Vehicle lighting lamp and vehicle headlamp

文档序号：1713268 发布日期：2019-12-13 浏览：15次中文

阅读说明：本技术 车辆用照明灯具以及车辆用前照灯 (Vehicle lighting lamp and vehicle headlamp ) 是由内田直树鬼头壮宜于 2018-04-10 设计创作，主要内容包括：作为车辆用照明灯具的一方式的车辆用前照灯(1)具备光源(52R、52G、52B)和对从该光源(52R、52G、52B)入射的光进行衍射的衍射光栅(54R、54G、54B)。由衍射光栅(54R、54G、54B)衍射的光以规定的配光图案照射。向衍射光栅(54R、54G、54B)入射的光中的在衍射光栅(54R、54G、54B)中直行并透过的成分(LCR、LCG、LCB)所投影的投影区域(AR)比配光图案靠下侧,位于车辆的驾驶员的视野被所述车辆阻碍的范围(RNG)内。(A vehicle headlamp (1) as one mode of a vehicle lighting lamp is provided with light sources (52R, 52G, 52B) and diffraction gratings (54R, 54G, 54B) which diffract light incident from the light sources (52R, 52G, 52B). The light diffracted by the diffraction gratings (54R, 54G, 54B) is irradiated with a predetermined light distribution pattern. Of the light incident on the diffraction gratings (54R, 54G, 54B), the component (LC) that passes through the diffraction gratings (54R, 54G, 54B) while traveling straight is present R 、LC G 、LC B ) The projected projection Area (AR) is located below the light distribution pattern and within a Range (RNG) in which the field of view of the driver of the vehicle is obstructed by the vehicle.)

1. A vehicular illumination lamp is characterized by comprising:

A light source; and

A diffraction grating that diffracts light incident from the light source;

The light diffracted by the diffraction grating is irradiated with a predetermined light distribution pattern,

A projection area, onto which a component that is transmitted while traveling straight through the diffraction grating is projected, of the light incident on the diffraction grating is located below the light distribution pattern and within a range in which a field of view of a driver of the vehicle is blocked by the vehicle.

2. The vehicular illumination lamp according to claim 1,

The light distribution pattern is a light distribution pattern of low beams.

3. The vehicular illumination lamp according to claim 1 or 2,

The light distribution pattern has a luminosity distribution.

4. The vehicular illumination lamp according to claim 3,

Having a plurality of light-emitting optical systems including one said light source and one said diffraction grating,

Further comprises a combining optical system for combining the lights emitted from the light emitting optical systems,

The light sources in the respective light emitting optical systems emit light of predetermined wavelengths different from each other, and the diffraction grating in the respective light emitting optical systems diffracts the light from the light sources so that the light combined by the combining optical system becomes a light distribution pattern of low beams.

5. The vehicular illumination lamp according to claim 4,

The components that are straight and transmitted through the diffraction grating in each of the light-emitting optical systems are combined by the combining optical system and projected onto the projection area.

6. A vehicular illumination lamp is characterized by comprising:

A light source;

A diffraction grating that diffracts light incident from the light source; and

An optical element disposed on an optical path of the light component between a projection area of the light component that passes through the diffraction grating while traveling straight and the diffraction grating, and configured to reduce an energy density of the light;

Among the light beams emitted from the diffraction grating, the light beams diffracted by the diffraction grating are irradiated with a predetermined light distribution pattern.

7. The vehicular illumination lamp according to claim 6,

The optical element is disposed in the housing.

8. The vehicular illumination lamp according to claim 6,

The optical element is a light blocking element.

9. The vehicular illumination lamp according to claim 6,

The optical element is a light diffusing element.

10. The vehicular illumination lamp according to any one of claims 6 to 9,

The projection area is located outside the light distribution pattern.

11. The vehicular illumination lamp according to any one of claims 6 to 9,

The light distribution pattern has a prescribed luminous intensity distribution,

the projection region is included in a region of the light distribution pattern having a luminous intensity lower than a half value of a maximum luminous intensity in a luminous intensity distribution of the light diffracted by the diffraction grating.

12. The vehicular illumination lamp according to claim 10 or 11,

Having a plurality of light-emitting optical systems including one said light source and one said diffraction grating,

Further comprises a combining optical system for combining the lights emitted from the light emitting optical systems,

13. The vehicular illumination lamp according to claim 12,

The light components that are straight and transmitted through the diffraction grating in each of the light emitting optical systems are combined by the combining optical system,

The optical element reduces the energy density of the light component synthesized by the synthesizing optical system.

14. A vehicular illumination lamp is characterized by comprising:

A light source; and

A diffraction grating that diffracts light incident from the light source;

A light distribution pattern having a predetermined luminous intensity distribution is formed by the light diffracted by the diffraction grating and the light that passes through the diffraction grating in a straight line,

the projection region of the light that passes through the diffraction grating in the light distribution pattern is located in a region having a luminous intensity higher than half the maximum luminous intensity in the luminous intensity distribution of the light diffracted by the diffraction grating.

15. The vehicular illumination lamp according to claim 14,

The projection area is located at a position avoiding a portion of the luminosity distribution that becomes the highest luminosity.

16. The vehicular illumination lamp according to claim 15,

The zones are hot zones.

17. The vehicular illumination lamp according to claim 16,

The light distribution pattern is a light distribution pattern of low beams.

18. The vehicular illumination lamp according to claim 17,

Having a plurality of light-emitting optical systems including one said light source and one said diffraction grating,

Further comprises a combining optical system for combining the lights emitted from the light emitting optical systems,

The light sources in the respective light emitting optical systems emit light of predetermined wavelengths different from each other, and the diffraction gratings in the respective light emitting optical systems emit light from the light sources so that the light synthesized by the synthesizing optical system becomes the light distribution pattern.

19. The vehicular illumination lamp according to claim 18,

The light that travels straight and passes through the diffraction grating in each of the light-emitting optical systems is synthesized by the synthesizing optical system and irradiated to the projection area.

20. A vehicular illumination lamp is characterized by comprising:

A light source; and

a diffraction grating that diffracts light incident from the light source;

The light emitted from the diffraction grating is irradiated with a light distribution pattern having a predetermined luminous intensity distribution,

In a projection region of the light that is transmitted straight through the diffraction grating in the light distribution pattern, the light intensity of the light that is diffracted by the diffraction grating and is irradiated to the projection region is smaller than the light intensity of the light that is irradiated to the outer periphery of the projection region.

21. The vehicular illumination lamp according to claim 20,

the total value of the luminous intensity of the light diffracted by the diffraction grating and irradiated to the projection area and the luminous intensity of the light which is transmitted straight through the diffraction grating and irradiated to the projection area is lower than the highest luminous intensity in the luminous intensity distribution of the light diffracted by the diffraction grating.

22. The vehicular illumination lamp according to claim 21,

The illuminance of the light diffracted by the diffraction grating and irradiated to the projection area is zero.

23. The vehicular illumination lamp according to any one of claims 20 to 22,

The projection region is included in a region having a luminous intensity higher than a half value of the highest luminous intensity in the luminous intensity distribution of the light diffracted by the diffraction grating.

24. The vehicular illumination lamp according to claim 23,

The projection region includes a position of highest luminosity in the luminosity distribution of the light diffracted by the diffraction grating.

25. The vehicular illumination lamp according to any one of claims 20 to 22,

Having a plurality of light-emitting optical systems including one said light source and one said diffraction grating,

Further comprises a combining optical system for combining the lights emitted from the light emitting optical systems,

26. The vehicular illumination lamp according to claim 25,

27. The vehicular illumination lamp according to any one of claims 20 to 22,

having a plurality of light-emitting optical systems including one said light source and one said diffraction grating,

The light sources in the respective light emitting optical systems emit light of predetermined wavelengths different from each other, and the diffraction gratings in the respective light emitting optical systems emit light from the light sources so as to form the light distribution pattern at a position separated by a predetermined distance from the vehicle.

28. A vehicle headlamp characterized in that,

Comprises at least two light emitting optical systems having a light source and a diffraction grating,

The light sources in the respective light emitting optical systems emit light of predetermined wavelengths different from each other,

The diffraction grating in each of the light-emitting optical systems diffracts light from the light source so that light synthesized from light emitted from each of the light-emitting optical systems becomes a light distribution pattern for night illumination.

29. The vehicular headlamp according to claim 28,

At least three of the light-emitting optical systems are provided.

30. The vehicular headlamp according to claim 28 or 29,

The light source device further includes a combining optical system that combines the external shapes of the lights emitted from the light emitting optical systems.

31. The vehicular headlamp according to claim 30, wherein,

The synthesis optical system has at least one wavelength selective filter,

The wavelength selective filter combines light transmitted through the wavelength selective filter and light reflected by the wavelength selective filter.

Technical Field

The present invention relates to a vehicle lighting fixture and a vehicle headlamp.

Background

A vehicle headlamp, such as an automobile headlamp, is configured to emit at least low beams for illuminating the front at night. In order to form a light distribution pattern of the low beam, a shade is used which blocks a part of the light emitted from the light source. However, there is a demand for a vehicle headlamp that is compact due to diversification of the design of the vehicle.

Patent document 1 listed below describes a vehicle headlamp capable of forming a light distribution pattern of low beams without using a shade. The vehicle headlamp includes a hologram element and a light source for irradiating the hologram element with reference light. The hologram element is calculated to form a light distribution pattern of low beams by diffracted light regenerated by irradiation with the reference light. In this vehicle headlamp, since the light distribution pattern of the low beam is formed by the hologram element, a shade is not required, and the vehicle headlamp can be downsized.

Disclosure of Invention

The lighting lamp for vehicle of the invention includes: a light source; and a diffraction grating that diffracts light incident from the light source, wherein the light diffracted by the diffraction grating is irradiated with a predetermined light distribution pattern, and wherein a projection area, onto which a component that passes through the diffraction grating while traveling straight, of the light incident on the diffraction grating is projected, is located below the light distribution pattern and within a range in which a field of vision of a driver of a vehicle is obstructed by the vehicle.

The component that passes straight through the diffraction grating corresponds to the 0 th order light and has a luminous intensity higher than that of the higher order light after the 1 st order light. However, in the vehicle lighting fixture of the present invention, since the projection region on which the component corresponding to the 0 th order light is projected is located within the range in which the field of view of the driver of the vehicle is not obstructed by the vehicle, it is possible to suppress a reduction in the driver's attention-attracting ability due to the component. Therefore, driving can be performed more easily than in the case where the 0 th light is located in the field of view of the driver of the automobile.

The light distribution pattern may be a light distribution pattern of low beams. In this case, in the vehicular illumination lamp according to the present invention, the light diffracted by the diffraction grating is irradiated with the light distribution pattern of the low beam, and the light distribution pattern of the low beam can be formed without using a shade. Therefore, the size can be reduced as compared with a vehicle illumination lamp using a shade.

in addition, the light distribution pattern may have a luminous intensity distribution. In this case, if the light intensity distribution is such that the central portion of the light distribution pattern is bright and the peripheral portions other than the central portion are relatively dark, a natural light distribution pattern can be obtained without giving a sense of incongruity to the driver.

Further, the light source may emit light of a predetermined wavelength different from each other in each of the light emitting optical systems, and the diffraction grating in each of the light emitting optical systems may diffract the light from the light source so that the light synthesized by the synthesizing optical system becomes a light distribution pattern of a low beam.

In this case, in each light emitting optical system, light of a predetermined wavelength emitted from the light source is diffracted by the diffraction grating to form a light distribution pattern. In this case, in each light-emitting optical system, since the light diffracted by the diffraction grating has a predetermined wavelength as described above, even if the diffraction grating has wavelength dependency, it is possible to suppress occurrence of bleeding in the vicinity of the edge of the light distribution pattern in the light emitted from each diffraction grating. The light having the light distribution pattern in which the color bleeding is suppressed is synthesized by the synthesizing optical system to form a light distribution pattern of low beam. Therefore, the low beam irradiated by the vehicular illumination lamp according to the present invention can suppress the occurrence of color bleeding in the vicinity of the edge of the light distribution pattern.

In addition, the components that pass through the diffraction grating in the respective light-emitting optical systems while traveling straight may be combined by the combining optical system and projected onto the projection area. In this case, as described above, even if the diffraction grating has wavelength dependence, the components transmitted through the respective diffraction gratings can be made to be the same color. Therefore, it is possible to reduce the possibility that a pedestrian or the like outside the vehicle unnecessarily recognizes the projection area.

Further, a vehicle lighting fixture according to the present invention includes: a light source; a diffraction grating that diffracts light incident from the light source; and an optical element disposed on an optical path of the light component between a projection area of the light component that passes through the diffraction grating while traveling straight and the diffraction grating, the optical element reducing an energy density of the light, and the light diffracted by the diffraction grating among the light emitted from the diffraction grating being irradiated with a predetermined light distribution pattern.

The light component that passes straight through the diffraction grating corresponds to the above-mentioned 0 th order light, and the light diffracted by the diffraction grating corresponds to the above-mentioned higher order diffracted light. Therefore, light that travels straight and passes through the diffraction grating tends to have higher luminosity than light diffracted by the diffraction grating. However, in the vehicle illumination lamp according to the present invention, an optical element that reduces the energy density of light is disposed on the optical path of the light component between the diffraction grating and the projection area of the light component corresponding to the 0 th order light. Therefore, even if the light component that is transmitted straight through the diffraction grating has a higher luminous intensity than the light component diffracted by the diffraction grating, the energy density of the light component is reduced by the optical element. Therefore, compared to a light distribution pattern formed by light diffracted by the diffraction grating among light emitted from the diffraction grating, it is possible to suppress the projected area of the light component that travels straight through the diffraction grating and passes through from becoming significantly brighter. As described above, the vehicle lamp according to the present invention can be driven more easily than a vehicle lamp without the optical element.

In addition, when an optical element for reducing the energy density of light is provided, a housing for housing the light source and the diffraction grating may be provided, and the optical element may be disposed in the housing. In this case, the light component corresponding to the 0 th order light can be reduced from being emitted to the outside of the vehicle. Therefore, the projection area of the light component corresponding to the 0 th order light can be suppressed from becoming significantly bright outside the vehicle, and as a result, the driver, the pedestrian, or the like can be suppressed from being unnecessarily aware of the projection area.

In addition, when an optical element for reducing the energy density of light is provided, the optical element may be a light blocking element or a light diffusing element. Therefore, in the vehicle lighting fixture of the present invention, the light blocking element or the light diffusing element can be selected as the optical element according to the vehicle type or the like mounted on the vehicle lighting fixture.

In addition, when an optical element that reduces the energy density of light is provided, the projection region may be located outside the light distribution pattern. In this case, as compared with the case where the projection region is located within the light distribution pattern, it is possible to suppress a part of the light distribution pattern from becoming significantly bright, and as a result, it is possible to more easily drive the vehicle.

In addition, in the case where the optical element for reducing the energy density of light is provided, the light distribution pattern may have a predetermined luminous intensity distribution, and the projection region may be included in a region of the light distribution pattern having a luminous intensity lower than half the maximum luminous intensity in the luminous intensity distribution of light diffracted by the diffraction grating.

In this case, as compared with a case where the projection region is included in a region higher than the half value of the maximum luminous intensity in the luminous intensity distribution of the light diffracted by the diffraction grating, the luminous intensity distribution of the light distribution pattern can be easily and smoothly formed with reference to the position where the maximum luminous intensity is present in the luminous intensity distribution of the light diffracted by the diffraction grating.

in addition, in the case where the optical element for reducing the energy density of light is provided, the optical element may include a plurality of light emitting optical systems each including one light source and one diffraction grating, and a combining optical system for combining the light emitted from the light emitting optical systems, the light sources in the light emitting optical systems may emit light of predetermined wavelengths different from each other, and the diffraction gratings in the light emitting optical systems may diffract the light from the light sources so that the light combined by the combining optical systems forms the light distribution pattern.

In addition, in the case where an optical element for reducing the energy density of light is provided, the light components that pass through the diffraction grating in each of the light-emitting optical systems in a straight line may be combined by the combining optical system, and the optical element may reduce the energy density of the light components combined by the combining optical system.

In this case, the irradiation area of the light component irradiated to the optical element can be reduced as compared with a case where the light components that travel straight and transmit through the diffraction gratings in the respective light emitting optical systems are not combined. Therefore, it is possible to suppress a decrease in the energy density of light diffracted by the diffraction grating among the light emitted from the diffraction grating due to the optical element.

Further, a vehicle lighting fixture according to the present invention includes: a light source; and a diffraction grating configured to diffract light incident from the light source, wherein a light distribution pattern having a predetermined luminous intensity distribution is formed by the light diffracted by the diffraction grating and the light that is transmitted straight through the diffraction grating, and a projection region of the light that is transmitted straight through the diffraction grating in the light distribution pattern is located in a region where the luminous intensity of the light diffracted by the diffraction grating is higher than a half value of a maximum luminous intensity.

The light that passes straight through the diffraction grating corresponds to the 0 th order light, and the light diffracted by the diffraction grating corresponds to the higher order diffracted light. Therefore, light that travels straight and passes through the diffraction grating tends to have higher luminosity than light diffracted by the diffraction grating. However, in the vehicle lighting fixture of the present invention, the projected area of the light corresponding to the 0 th order light is located in an area having a light intensity higher than a half value of the maximum light intensity in the light intensity distribution of the light corresponding to the high-order diffracted light. Therefore, even if light corresponding to 0 th order light is irradiated to the projection region, the projection region in the light distribution pattern can be suppressed from being brightened significantly. Therefore, the vehicle headlamp according to the present invention can be driven more easily than a case where the projection region is disposed outside the region where the luminous intensity is higher than the half value of the maximum luminous intensity in the luminous intensity distribution of the light diffracted by the diffraction grating.

In addition, when the projection region of the light corresponding to the 0 th order light is located in a region having a higher luminous intensity than a half value of the highest luminous intensity in the luminous intensity distribution of the light corresponding to the high-order diffracted light, it is preferable that the projection region is located at a position avoiding a portion having the highest luminous intensity in the luminous intensity distribution. In this case, it is possible to suppress the portion of the light intensity distribution of light corresponding to the high-order diffracted light from becoming excessively bright.

In addition, when the projection region of the light corresponding to the 0 th order light is located in a region having a luminous intensity higher than a half value of the highest luminous intensity in the luminous intensity distribution of the light corresponding to the high-order diffracted light, the region is preferably a hot region. In this case, while light equivalent to 0 th order light is used as the light distribution pattern, the projected area can be suppressed from being significantly brightened in the light distribution pattern.

Further, when the projection region of the light corresponding to the 0 th order light is located in a region where the light corresponding to the high-order diffracted light has a higher luminous intensity than a half value of the highest luminous intensity in the luminous intensity distribution, the projector may include a plurality of light emitting optical systems including one light source and one diffraction grating, and a synthesizing optical system for synthesizing the lights emitted from the light emitting optical systems, wherein the light sources in the light emitting optical systems emit lights having different predetermined wavelengths from each other, and the diffraction gratings in the light emitting optical systems emit the lights from the light sources so that the lights synthesized by the synthesizing optical systems form the light distribution pattern.

In this case, light of a predetermined wavelength emitted from each light source is formed into a light distribution pattern by the diffraction grating. In this case, in each light-emitting optical system, since the light diffracted by the diffraction grating has a predetermined wavelength, even if the diffraction grating has wavelength dependency, it is possible to suppress occurrence of bleeding in the vicinity of the edge of the light distribution pattern in the light emitted from each diffraction grating. The light having the light distribution pattern in which the color bleeding is suppressed is synthesized by the synthesizing optical system to form the light distribution pattern. Therefore, the occurrence of bleeding in the vicinity of the edge of the light distribution pattern can be suppressed.

In addition, when the projection area of the light corresponding to the 0 th order light is located in an area where the light intensity distribution of the light corresponding to the high-order diffracted light has a light intensity higher than a half value of the maximum light intensity, the light that has passed through the diffraction grating in each of the light emitting optical systems while traveling straight may be synthesized by the synthesizing optical system and irradiated to the projection area. In this case, as described above, even if the diffraction grating has wavelength dependency, the 0 th order light transmitted through each diffraction grating can be made to be the same color as white. Therefore, the driver can be less unnecessarily aware of the projection area, and driving can be facilitated.

Further, a vehicle lighting fixture according to the present invention includes: a light source; and a diffraction grating which diffracts light incident from the light source, wherein the light emitted from the diffraction grating is irradiated with a light distribution pattern having a predetermined luminous intensity distribution, and in a projection region of the light which is transmitted while being straight on the diffraction grating in the light distribution pattern, the luminous intensity of the light which is diffracted by the diffraction grating and is irradiated to the projection region is smaller than the luminous intensity of the light which is irradiated to the outer peripheral edge of the projection region.

The light that passes straight through the diffraction grating corresponds to the 0 th order light, and the light diffracted by the diffraction grating corresponds to the higher order diffracted light. Therefore, light that travels straight and passes through the diffraction grating tends to have higher luminosity than light diffracted by the diffraction grating. However, in the vehicle lighting fixture of the present invention, in the projection area of the light corresponding to the 0 th order light, the light corresponding to the high-order diffracted light has a lower luminous intensity than the light irradiated to the outer peripheral edge of the projection area. Therefore, even when light corresponding to 0 th order light is irradiated to the projection area, it is possible to reduce the projection area from being significantly brightened in the light distribution pattern. Therefore, the vehicle lighting fixture of the present invention can be driven more easily than in the case where the light intensity of the high-order diffracted light in the projection area is equal to or higher than the light intensity of the light irradiated to the outer peripheral edge of the projection area.

In the projection region of light corresponding to 0 th order light, when the light corresponding to the high-order diffracted light is smaller in intensity than the light irradiated to the outer periphery of the projection region, the total value of the light intensity of the light diffracted by the diffraction grating and irradiated to the projection region and the light intensity of the light transmitted straight through the diffraction grating and irradiated to the projection region may be lower than the highest light intensity in the light intensity distribution of the light diffracted by the diffraction grating.

In this case, the luminous intensity distribution of the light distribution pattern can be easily and smoothly formed with reference to the position where the highest luminous intensity is obtained in the luminous intensity distribution of the light diffracted by the diffraction grating.

in the projection region of the light corresponding to the 0 th order light, when the light corresponding to the high-order diffracted light is lower in intensity than the light irradiated to the outer periphery of the projection region, the light diffracted by the diffraction grating and irradiated to the projection region may be zero in intensity.

In this case, even when the difference between the light intensity of the light corresponding to the 0 th order light and the light intensity of the light corresponding to the high-order diffracted light is large, the projected area is reduced from being brightened significantly in the light distribution pattern, and a smooth light intensity distribution is easily formed in the entire light distribution pattern.

In the projection region of the light corresponding to the 0 th order light, when the light corresponding to the high-order diffracted light has a lower luminous intensity than the light irradiated to the outer periphery of the projection region, the projection region may be included in a region having a luminous intensity higher than half the maximum luminous intensity in the luminous intensity distribution of the light diffracted by the diffraction grating.

In this case, the projected area in the light distribution pattern can be reduced from becoming significantly brighter as compared with a case where the projected area is included in an area equal to or less than half the maximum luminous intensity in the luminous intensity distribution of the light diffracted by the diffraction grating.

In the projection region of the light corresponding to the 0 th order light, when the light corresponding to the high-order diffracted light has a lower luminous intensity than the light irradiated to the outer periphery of the projection region, the projection region may include a position having the highest luminous intensity in the luminous intensity distribution of the light diffracted by the diffraction grating.

in this case, the brightest region in the light distribution pattern does not change substantially regardless of whether the light intensity of the light corresponding to the 0 th order light is large or not. Therefore, the luminous intensity distribution of the light distribution pattern can be formed more smoothly with reference to the position where the highest luminous intensity is obtained in the luminous intensity distribution of the light diffracted by the diffraction grating.

In addition, when the light intensity corresponding to the high-order diffracted light is smaller than the light intensity of the light irradiated to the outer periphery of the projection area in the projection area of the light corresponding to the 0 th order light, a plurality of light emitting optical systems including one light source and one diffraction grating may be provided, and a synthesizing optical system may be further provided that synthesizes the light emitted from the light emitting optical systems, the light sources in the light emitting optical systems may emit light of predetermined wavelengths different from each other, and the diffraction gratings in the light emitting optical systems may emit the light from the light sources such that the light synthesized by the synthesizing optical system forms the light distribution pattern.

In this case, in each light emitting optical system, light of a predetermined wavelength emitted from the light source is diffracted by the diffraction grating to form a light distribution pattern. In this case, in each light-emitting optical system, since the light diffracted by the diffraction grating has a predetermined wavelength as described above, even if the diffraction grating has wavelength dependency, it is possible to suppress occurrence of bleeding in the vicinity of the edge of the light distribution pattern in the light emitted from each diffraction grating. The light having the light distribution pattern in which the color bleeding is suppressed is synthesized by the synthesizing optical system to form the light distribution pattern. Therefore, the occurrence of bleeding in the vicinity of the edge of the light distribution pattern formed by the vehicle lamp of the present invention can be suppressed.

In the projection area of the light corresponding to the 0 th order light, when the light corresponding to the high-order diffracted light is lower in intensity than the light irradiated to the outer periphery of the projection area, the light which travels straight through the diffraction grating in each of the light-emitting optical systems may be synthesized by the synthesizing optical system and irradiated to the projection area. In this case, as described above, even if the diffraction grating has wavelength dependence, the components transmitted through the respective diffraction gratings can be made to be the same color. Therefore, the driver can be less unnecessarily aware of the projection area, and driving can be facilitated.

In the case where the light intensity corresponding to the high-order diffracted light is smaller than the light intensity of the light irradiated to the outer periphery of the projection area in the projection area of the light corresponding to the 0 th order light, a plurality of light-emitting optical systems including one light source and one diffraction grating may be provided, the light sources in the light-emitting optical systems may emit light having different predetermined wavelengths from each other, and the diffraction gratings in the light-emitting optical systems may emit light from the light sources so as to form the light distribution pattern at positions separated by a predetermined distance from the vehicle.

In this case, since the above-described combining optical system is not used, a simple configuration can be provided.

the vehicle headlamp of the present invention includes at least two light emitting optical systems each having a light source and a diffraction grating, wherein the light sources in the light emitting optical systems emit light of predetermined wavelengths different from each other, and the diffraction gratings in the light emitting optical systems diffract the light from the light sources so that the light synthesized by the light emitted from the light emitting optical systems becomes a light distribution pattern for night illumination.

This vehicle headlamp can form a light distribution pattern of low beams without using a shade, as in the vehicle headlamp described in patent document 1, and therefore, can be made smaller than the vehicle headlamp using a shade, as in the vehicle headlamp described in patent document 1. In each of the light emitting optical systems, light of a predetermined wavelength emitted from the light source is diffracted by the diffraction grating to form a light distribution pattern. In this case, in each light-emitting optical system, since the light diffracted by the diffraction grating has a predetermined wavelength as described above, even if the diffraction grating has wavelength dependency, it is possible to suppress occurrence of bleeding in the vicinity of the edge of the light distribution pattern in the light emitted from each diffraction grating. The light distribution pattern for night illumination is formed by light synthesis of the light distribution pattern with the color bleeding suppressed. Therefore, the low beam irradiated by the vehicle headlamp of the present invention can suppress the occurrence of color bleeding in the vicinity of the edge of the light distribution pattern, as compared with the case where white light is diffracted by the diffraction grating as in patent document 1. The light emitted from each light-emitting optical system may be combined in the vehicle headlamp or may be combined outside the vehicle headlamp.

In addition, when at least two light emitting optical systems having a light source and a diffraction grating are provided, it is preferable that at least three light emitting optical systems are provided.

In this case, light of three primary colors can be used. Therefore, by adjusting the luminous intensity of the light emitted from each light-emitting optical system, light of a desired color can be irradiated.

In addition, in the case where at least two light emitting optical systems each having a light source and a diffraction grating are provided, it is preferable that a combining optical system for combining the external shapes of the lights emitted from the light emitting optical systems is further provided, and in this case, the combining optical system may further include at least one wavelength selective filter for combining the light transmitted through the wavelength selective filter and the light reflected by the wavelength selective filter.

In this case, since the lights emitted from the respective light emitting optical systems are synthesized by the synthesizing optical system and then emitted from the vehicle headlamp, it is possible to further suppress the occurrence of color bleeding in the vicinity of the edge of the light distribution pattern to be irradiated regardless of the distance from the vehicle. Further, since the lights emitted from the respective light emitting optical systems are combined by the combining optical system and then emitted from the vehicle headlamp, the emission portion of the vehicle headlamp from which the combined light is emitted can be reduced and the degree of freedom in design can be improved, as compared with a case where the lights emitted from the respective light emitting optical systems are not combined and emitted from the vehicle headlamp and combined outside the vehicle headlamp.

Drawings

Fig. 1 is a schematic cross-sectional view showing a vehicle including a vehicle headlamp according to a first embodiment of the present invention.

Fig. 2 is an enlarged view of an optical system unit of the vehicle headlamp of fig. 1.

Fig. 3 is a diagram showing a light distribution pattern of low beams.

Fig. 4 is a diagram showing a projection area of 0 th order light.

Fig. 5 is a view showing an optical system unit of a vehicle headlamp according to a second embodiment of the present invention, similarly to fig. 2.

Fig. 6 is a schematic cross-sectional view showing a vehicle including a vehicle headlamp according to a third embodiment of the present invention.

Fig. 7 is a view showing an optical system unit of a vehicle headlamp according to a fourth embodiment of the present invention, similarly to fig. 2.

Fig. 8 is a diagram showing a light distribution pattern of low beam and a light distribution pattern of light for visual confirmation of a logo.

Fig. 9 is a diagram showing a light distribution pattern of high beam.

Fig. 10 is a schematic cross-sectional view showing a vehicle including a vehicle headlamp according to a fifth embodiment of the present invention.

Fig. 11 is an enlarged view of an optical system unit of the vehicle headlamp of fig. 10.

Fig. 12 is a diagram showing a light distribution pattern of low beams and a luminous intensity distribution of the light distribution pattern.

Fig. 13 is a view showing an optical system unit of a vehicle headlamp according to a sixth embodiment of the present invention, similarly to fig. 11.

Fig. 14 is a view showing a light distribution pattern of low beam and a light distribution pattern of light for visual confirmation of a logo.

Fig. 15 is a diagram showing a light distribution pattern of low beams and a luminous intensity distribution of the light distribution pattern.

Fig. 16 is a diagram showing a light distribution pattern of low beams and a luminous intensity distribution of the light distribution pattern in the case of 0-time non-irradiation of light beams.

Fig. 17 is a schematic cross-sectional view showing a vehicle including a vehicle headlamp according to a ninth embodiment of the present invention.

fig. 18 is an enlarged view of the optical system unit of fig. 17.

Fig. 19 is a view showing a light distribution pattern.

Fig. 20 is a view showing an optical system unit of a vehicle headlamp according to a tenth embodiment of the present invention, similarly to fig. 18.

Detailed Description

hereinafter, a mode of a vehicle lamp and a vehicle headlamp for implementing the present invention will be described by way of example together with the attached drawings. The following embodiments are provided for easy understanding of the present invention, and are not intended to limit the present invention. The present invention can be modified and improved according to the following embodiments without departing from the gist thereof.

First, the configuration of the vehicular illumination lamp according to the present embodiment will be described.

(first embodiment)

Fig. 1 is a schematic cross-sectional view showing a vehicle including a vehicle headlamp according to the present embodiment. The vehicle headlamp 1 of the present embodiment includes a housing 10 and a lamp unit 20.

The housing 10 includes a lamp housing 11, a front cover 12, and a rear cover 13 as main components. The front cover 12 is fixed to the lamp housing 11 so as to close a front opening of the lamp housing 11. An opening smaller than the front is formed in the rear of the lamp housing 11, and the rear cover 13 is fixed to the lamp housing 11 so as to close the opening.

A space formed by the lamp housing 11, the front cover 12 closing the front opening of the lamp housing 11, and the rear cover 13 closing the rear opening of the lamp housing 11 is a lamp chamber R in which the lamp unit 20 is housed.

The lamp unit 20 includes a heat sink 30, a cooling fan 40, and an optical system unit 50 as main components. The lamp unit 20 is fixed to the housing 10 by a configuration not shown.

The heat sink 30 has a metal bottom plate 31 extending substantially in the horizontal direction, and a plurality of fins 32 are provided integrally with the bottom plate 31 on the lower surface side of the bottom plate 31. The cooling fan 40 is disposed with a gap from the heat sink 32 and fixed to the heat sink 30. The radiator 30 is cooled by an air flow generated by the rotation of the cooling fan 40.

An optical system unit 50 is disposed on the upper surface of the bottom plate 31 of the heat sink 30. The optical system unit 50 includes a first light-emitting optical system 51R, a second light-emitting optical system 51G, a third light-emitting optical system 51B, a combining optical system 55, and a cover 59.

Fig. 2 is an enlarged view of an optical system unit of the vehicle headlamp of fig. 1. As shown in fig. 2, the first light-emitting optical system 51R includes a light source 52R, a collimator lens 53R, and a diffraction grating 54R. The light source 52R is a laser element that emits laser light of a predetermined wavelength, and in the present embodiment, the peak wavelength of the emission power is, for example, red laser light of 638 nm. The optical system unit 50 includes a circuit board, not shown, on which the light source 52R is mounted. Power is supplied to the light source 52R through the circuit board.

the collimator lens 53R is a lens for collimating the laser beam emitted from the light source 52R in the fast axis direction and the slow axis direction. The collimator lens for collimating the laser light in the fast axis direction and the collimator lens for collimating the laser light in the slow axis direction may be provided separately.

The diffraction grating 54R emits the laser beam emitted from the collimator lens 53R so as to form a predetermined light distribution pattern. Specifically, the diffraction grating 54R diffracts the laser light incident from the collimator lens 53R so that the light emitted from each of the first, second, and third light-emitting optical systems 51R, 51G, and 51B in the combining optical system 55 described below becomes a light distribution pattern of the low beam L. The light distribution pattern also includes a luminous intensity distribution. Therefore, the diffraction grating 54R of the present embodiment diffracts the laser light incident from the collimator lens 53R so that the laser light emitted from the diffraction grating 54R has the same outer shape as the outer shape of the light distribution pattern of the low beam L and has the light intensity distribution based on the light intensity distribution of the light distribution pattern of the low beam L.

the light diffracted by the diffraction grating 54R is high-order diffracted light having an order of 1 or more, and 0-order light which is not diffracted by the diffraction grating 54R but passes straight is emitted from the diffraction grating 54R in addition to the high-order diffracted light. That is, the light emitted from the diffraction grating 54R includes a high-order diffraction light which is a light component diffracted by the diffraction grating 54R and a 0-order light which is a light component transmitted straight through the diffraction grating 54R. In the present embodiment, 0 th-order light that travels straight through the diffraction grating 54R and is transmitted therethrough is emitted from the diffraction grating 54R so that the projection area of the 0 th-order light beam LC emitted from the combining optical system 55 described later is located within a predetermined range below the light distribution pattern of the low beam L. For example, the diffraction grating 54R may diffract the laser light incident from the collimator lens 53R so as to emit high-order diffracted light in a state shifted to the upper side than the direction of the 0 th-order light traveling straight in the diffraction grating 54R.

Thus, the first light-emitting optical system 51R emits high-order diffracted light of the red component in the low beam L, and emits 0-order light of the red component in the 0-order beam LC. In the present embodiment, the high-order diffracted light of the red component emitted from the first light-emitting optical system 51R is the first light L_RThe 0 th order light of the red component is set as the first 0 th order light LC_R。

The second light emission optical system 51G includes a light source 52G, a collimator lens 53G, and a diffraction grating 54G, and the third light emission optical system 51B includes a light source 52B, a collimator lens 53B, and a diffraction grating 54B. The light sources 52G and 52B are each a laser element that emits laser light of a predetermined wavelength, and in the present embodiment, the light source 52G emits green laser light having a peak power wavelength of, for example, 515nm, and the light source 52B emits blue laser light having a peak power wavelength of, for example, 445 nm. The light sources 52G and 52B are mounted on the circuit board, and power is supplied to the light sources 52G and 52B through the circuit board.

The collimator lens 53G is a lens for collimating the fast axis direction and the slow axis direction of the laser beam emitted from the light source 52G, and the collimator lens 53B is a lens for collimating the fast axis direction and the slow axis direction of the laser beam emitted from the light source 52B. In the collimator lenses 53G and 53B, a collimator lens for collimating the laser beam in the fast axis direction and a collimator lens for collimating the laser beam in the slow axis direction may be provided separately from each other, similarly to the collimator lens 53R.

The diffraction grating 54G emits the laser beam emitted from the collimator lens 53G so as to form a predetermined light distribution pattern, and the diffraction grating 54B emits the laser beam emitted from the collimator lens 53B so as to form a predetermined light distribution pattern. Specifically, the diffraction gratings 54G and 54B diffract the laser beams incident from the collimator lenses 53G and 53B, respectively, so that the light beams emitted from the first light-emitting optical system 51R, the second light-emitting optical system 51G, and the third light-emitting optical system 51B in the combining optical system 55 form a light distribution pattern of the low beam L. As described above, the light distribution pattern also includes the light intensity distribution. Therefore, the diffraction gratings 54G and 54B of the present embodiment diffract the laser beams incident from the collimator lenses 53G and 53B, respectively, so that the laser beams emitted from the diffraction gratings 54G and 54B have the same outer shape as the outer shape of the light distribution pattern of the low beam L and have the light intensity distribution based on the light intensity distribution of the light distribution pattern of the low beam L.

The light diffracted by the diffraction grating 54G is high-order diffracted light having an order of 1 or more, and 0-order light which is not diffracted by the diffraction grating 54G but passes straight is emitted from the diffraction grating 54G in addition to the high-order diffracted light. That is, the light emitted from the diffraction grating 54G includes a high-order diffraction light which is a light component diffracted by the diffraction grating 54G and a 0 th-order light which is a light component that passes through the diffraction grating 54G in a straight line. In the present embodiment, 0 th-order light that travels straight through the diffraction grating 54G is emitted from the diffraction grating 54G so that the projection area of the 0 th-order light beam LC emitted from the combining optical system 55 described below is located within a predetermined range below the light distribution pattern of the low beam L. For example, the diffraction grating 54G may diffract the laser light incident from the collimator lens 53G so as to emit high-order diffracted light in a state shifted to the upper side than the direction of the 0 th-order light traveling straight in the diffraction grating 54G.

similarly, the light diffracted by the diffraction grating 54B is high-order diffracted light having a frequency of 1 or more, and 0-order light which is not diffracted by the diffraction grating 54B but passes straight is emitted from the diffraction grating 54B in addition to the high-order diffracted light. That is, the light emitted from the diffraction grating 54B includes a high-order diffraction light which is a light component diffracted by the diffraction grating 54G and a 0-order light which is a light component transmitted straight through the diffraction grating 54B. In the present embodiment, 0 th-order light that travels straight through the diffraction grating 54B and is transmitted therethrough is emitted from the diffraction grating 54B so that the projection area of the 0 th-order light beam LC emitted from the combining optical system 55 described later is located within a predetermined range below the light distribution pattern of the low beam L. For example, the diffraction grating 54B may diffract the laser light incident from the collimator lens 53B so that the high-order diffracted light is emitted in a state shifted to the upper side than the direction of the 0 th-order light traveling straight in the diffraction grating 54B.

Thus, the second light-emitting optical system 51G emits high-order diffracted light of the green component in the low beam L, and emits 0-order light of the green component in the 0-order beam LC. In addition, the third light-emitting optical system 51B emits high-order diffracted light of the blue component in the low beam L, and emits 0-order light of the blue component in the 0-order beam LC. In the present embodiment, the high-order diffracted light of the green component emitted from the second light-emitting optical system 51G is the second light L_GThe 0 th light of the green component is set as the second 0 th light LC_GThe third light L is high-order diffracted light of blue component emitted from the third light-emitting optical system 51B_BThe 0 th order light of the blue component is set as the third 0 th order light LC_B. Therefore, in the present embodiment, the first light L_RHas the longest wavelength of the second light L_GThe third light L_BSuccessively shorter. Also, the first 0 th order light LC_Rhas the longest wavelength of (1), and second 0 th order light LC_GThird 0 th order light LC_BSuccessively shorter.

The light intensity distribution based on the light intensity distribution of the light distribution pattern of the low beam L means that the light intensities of the lights emitted from the diffraction gratings 54R, 54G, and 54B are also high in the portions of the light distribution pattern of the low beam L where the light intensities are high.

the second optical element 55s is the first light L to be combined by the first optical element 55f_RAnd the second light L_GAnd an optical element for combining the third light beam LB emitted from the third light-emitting optical system 51B. The second optical element 55s is also the first 0 th order light LC to be combined by the first optical element 55f_RAnd second 0 th order light LC_GAnd third 0-th light LC emitted from third light-emitting optical system 51B_BA resultant optical element. In the present embodiment, the second optical element 55s makes the first light L combined by the first optical element 55f_RAnd the second light L_Gtransmits and transmits the third light L_BReflect to thereby emit the first light L_RAnd the second light L_GAnd the third light L_BAnd (4) synthesizing. The second optical element 55s is configured to combine the first 0 th order light LC combined by the first optical element 55f_RAnd second 0 th order light LC_GTransmits and LC third 0 th light_BReflect to thereby mix the first 0 th order light LC_RSecond 0 th order light LC_GAnd third 0 th order light LC_BAnd (4) synthesizing.

As such a first optical element 55f and a second optical element 55s, a wavelength selective filter in which an oxide film is laminated on a glass substrate can be cited. By controlling the type and thickness of the oxide film, light having a wavelength longer than a predetermined wavelength can be transmitted and light having a wavelength shorter than the predetermined wavelength can be reflected.

Thus, the first light L is emitted from the combining optical system 55_RThe second light L_GAnd the third light L_BCombined to emit a low beam L, the first 0 th order light LC_RSecond 0 th order light LC_GAnd third 0 th order light LC_Bare combined to emit 0-order beamLC。

The cover 59 is fixed to the bottom plate 31 of the heat sink 30. The cover 59 has a substantially rectangular shape and is made of metal such as aluminum, for example. The first light-emitting optical system 51R, the second light-emitting optical system 51G, the third light-emitting optical system 51B, and the combining optical system 55 are disposed in a space inside the cover 59. Further, an opening 59H through which light emitted from the combining optical system 55 can pass is formed in front of the cover 59. The inner wall of the cover 59 is preferably made light absorbing by black anodizing or the like. By making the inner wall of the cover 59 light-absorbing, it is possible to suppress light reflected by the inner wall of the cover 59 due to unwanted reflection, refraction, or the like from being emitted from the opening 59H in an unwanted direction.

Next, the emission of light by the vehicle headlamp 1 of the present embodiment will be described.

First, laser light is emitted from the light sources 52R, 52G, and 52B by supplying power from a power supply not shown. As described above, the red laser beam is emitted from the light source 52R, the green laser beam is emitted from the light source 52G, and the blue laser beam is emitted from the light source 52B. The respective laser beams are collimated by the collimator lenses 53R, 53G, and 53B, and then enter the diffraction gratings 54R, 54G, and 54B. Then, as described above, the respective laser beams are diffracted by the diffraction gratings 54R, 54G, and 54B, and the first light L, which is the light of the red component of the light distribution pattern of the low beam L, is emitted from the first light-emitting optical system 51R_Rsecond light L, which is a green component of the light distribution pattern of the low beam L, is emitted from the second light-emitting optical system 51G_GThird light L, which is a blue component of the light distribution pattern of the low beam L, is emitted from the third light-emitting optical system 51B_B. As described above, the first 0 th light LC of the 0 th light as the red component is emitted from the first light-emitting optical system 51R as the 0 th light which is transmitted in the diffraction gratings 54R, 54G, and 54B in a straight line manner_RSecond 0 th light LC which is 0 th light of green component emitted from the second light-emitting optical system 51G_GThird 0 th light LC which is 0 th light of blue component emitted from the third light emission optical system 51B_B。

In the combining optical system 55, first, the first light L_RAnd the second light L_GSynthesized and emitted by the first optical element 55f, and the first 0 th-order light LC_RAnd second 0 th light LC_GSynthesized by the first optical element 55f and emitted. The first light L synthesized by the first optical element 55f_RAnd the second light L_GThe second optical element 55s and the third light L_BThe first 0 th light LC synthesized by the first optical element 55f_RAnd second 0 th light LC_GThe second optical element 55s and the third 0-th light LC_BAnd (4) synthesizing. At this time, the respective lights L_R、L_G、L_BIs the same as the low beam L, so the respective beams LR, L_G、L_BAre uniformly synthesized with each other. In addition, each 0 th order light LC_R、LC_G、LC_BIs also processed in the same way, so that each 0 th order light LC_R、LC_G、LC_BAre uniformly synthesized with each other. That is, the positions of the light-emitting optical systems and the combining optical system are finely adjusted so that the first light L is emitted_RSecond light L_GAnd the third light L_Band first 0 th order light LC_RSecond 0 th order light LC_GAnd third 0 th order light LC_BThe outer shape of (2) is combined by the synthesizing optical system as described above.

Thus, the first light L of red color_RGreen second light L_GAnd blue third light L_BThe synthesized light becomes white light. In addition, the first 0 th order light LC of red_RGreen second 0 th light LC_GAnd blue third 0 th primary light LC_BThe synthesized light becomes white 0 th order light. In addition, the first light L_RThe second light L_GAnd the third light L_BSince each of the light intensity distributions is obtained from the light intensity distribution of the light distribution pattern of the low beam L as described above, the white light obtained by the light combination of the light intensity distributions is obtained as the light intensity distribution of the low beam L.

The white light thus combined is emitted from the opening 59H of the cover 59, and the light is emitted from the vehicle headlamp 1 toward the front of the vehicle via the front cover 12. Since this light has a light distribution pattern of the low beam L, the irradiated light becomes the low beam L.

Fig. 3 is a diagram showing a light distribution pattern of the low beam L in the present embodiment. In fig. 3, S denotes a horizontal line, and the light distribution pattern is indicated by a thick line. A light distribution pattern PTN of the low beam L_LThe medium area LA1 is an area with the highest luminous intensity, and the luminous intensities of the areas LA2 and LA3 become lower in order. That is, the diffraction gratings 54R, 54G, and 54B diffract the light so that the combined light forms a light distribution pattern including the light intensity distribution of the low beam L.

The synthesized white 0 th-order light is emitted from the opening 59H of the cover 59, and the light is emitted from the vehicle headlamp 1 toward the lower side in the front direction of the vehicle through the front cover 12 and projected to the projection area below the light distribution pattern of the low beam L.

Fig. 4 is a diagram showing a projection area of 0 th order light. As shown in fig. 4, the projection area AR of the present embodiment is located within a range RNG in which the field of view of the driver of the automobile is blocked by the hood of the vehicle. That is, the projection area AR is located within the range RNG which becomes a blind spot for the driver of the automobile. The road surface illuminance in a region other than the projection region AR of the 0 th order light in the range RNG which is a blind spot of the driver of the automobile is set to be substantially 5 lux or less.

However, the hologram element of the vehicle headlamp in patent document 1 is calculated to irradiate 1 st beam for forming a light distribution pattern of a low beam toward the front of the vehicle and irradiate 0 th beam toward the front other than the light distribution pattern of the low beam. Therefore, in the vehicle headlamp in patent document 1, the possibility that the 0 th light causes glare can be prevented. The 0 th order light tends to have a higher light intensity than the light intensity of the high order diffracted light having the order of 1 or more. However, in the vehicle headlamp in patent document 1, the 0 th light emitted from the hologram element is not a light distribution pattern of the low beam, but the 0 th light is irradiated toward the front of the vehicle. Therefore, there is a demand for making driving easier.

Therefore, the vehicle headlamp 1 of the present embodiment includes the light sources 52R, 52G, and 52B and the diffraction gratings 54R, 54G, and 54B that diffract the light incident from the light sources 52R, 52G, and 52B.

The projection area AR, onto which 0 th order light, which is a component of light incident on the diffraction gratings 54R, 54G, and 54B and passing through the diffraction gratings 54R, 54G, and 54B straight, is projected, is located below the light distribution pattern diffracted and irradiated by the diffraction gratings 54R, 54G, and 54B. In addition, the projection area AR is located within a range RNG in which the field of view of the driver of the automobile is blocked by the automobile.

Therefore, the vehicle headlamp 1 of the present embodiment can suppress a reduction in the driver's attention-attracting ability due to the 0 th light having a higher luminous intensity than the luminous intensity of the high-order light after the 1 st light. Therefore, the vehicle headlamp 1 of the present embodiment can be driven more easily than when the 0 th light is positioned in the field of view of the driver of the automobile.

In the present embodiment, the light diffracted by the diffraction gratings 54R, 54G, and 54B is irradiated with a light distribution pattern of the low beam L. A light distribution pattern PTN of the low beam L_LAs shown in fig. 3, is a light distribution pattern PTN_LThe central portion of (a) is bright and the peripheral portions other than the central portion are relatively dark, so that a natural light distribution pattern without a sense of incongruity can be irradiated to the driver.

therefore, the vehicle headlamp 1 of the present embodiment can form the light distribution pattern PTN of the low beam L without using a shade_LTherefore, the vehicle headlamp can be downsized compared to a vehicle headlamp using a shade.

The vehicle headlamp 1 of the present embodiment includes a plurality of light emitting optical systems each including one light source and one diffraction grating. That is, the vehicle headlamp 1 has a first light-emitting optical system 51R including one light source 52R and one diffraction grating 54R, a second light-emitting optical system 51G including one light source 52G and one diffraction grating 54G, and a third light-emitting optical system 51B including one light source 52B and one diffraction grating 54B. In addition, the vehicle headlamp 1 of the present embodiment further includes a combining optical system 55 that combines the lights emitted from the respective light emitting optical systems 51R, 51G, and 51B. The light sources 52R, 52G, and 52B emit light beams having different predetermined wavelengths, and the diffraction gratings 54R, 54G, and 54B form a light distribution pattern PTN in which the light beams combined by the combining optical system 55 have the low beam L_LFor light sources 52R, 52G, 52BThe light is diffracted.

In this case, light of a predetermined wavelength emitted from the light sources 52R, 52G, and 52B is diffracted by the diffraction gratings 54R, 54G, and 54B to form the light distribution pattern PTN_L. At this time, in the respective light-emitting optical systems 51R, 51G, and 51B, since the light diffracted by the diffraction gratings 54R, 54G, and 54B has a predetermined wavelength, even if the diffraction gratings 54R, 54G, and 54B have wavelength dependency, the light distribution pattern PTN in the light emitted from the respective diffraction gratings 54R, 54G, and 54B can be suppressed_LProduces bleeding near the edge of the sheet. The light having the light distribution pattern in which the color bleeding is suppressed in this manner is synthesized by the synthesizing optical system 55 to form the light distribution pattern PTN of the low beam L_L. Therefore, the low beam L emitted from the vehicle headlamp 1 of the present embodiment can be suppressed in the light distribution pattern PTN_LBleeding occurred near the edge of (a).

In the vehicle headlamp 1 according to the present embodiment, the 0 th order light LC that travels straight through the diffraction gratings 54R, 54G, and 54B and is transmitted therethrough_R、LC_G、LC_BSynthesized by the synthesizing optical system 55 and projected onto the projection area AR. In this case, as described above, even if the diffraction gratings 54R, 54G, and 54B have wavelength dependency, the 0 th order light LC transmitted through the respective diffraction gratings 54R, 54G, and 54B can be caused to pass through_R、LC_G、LC_BAre the same white. Therefore, in the vehicle headlamp 1 of the present embodiment, it is possible to reduce the possibility that the pedestrian or the like outside the vehicle is unnecessarily aware of the projection area AR.

(second embodiment)

Next, a second embodiment of the present invention will be described in detail with reference to fig. 5. The same or equivalent components as those in the first embodiment are denoted by the same reference numerals and redundant description thereof is omitted unless otherwise specified.

Fig. 5 is a view showing an optical system unit of the vehicle headlamp according to the present embodiment, similarly to fig. 2. As shown in fig. 5, the optical system unit 50 of the vehicle headlamp according to the present embodiment is different from the optical system unit 50 according to the first embodiment in that the synthesizing optical system 55 is not provided, and the lights emitted from the first light-emitting optical system 51R, the second light-emitting optical system 51G, and the third light-emitting optical system 51B are emitted from the cover 59 without being synthesized. In the present embodiment, the light emission direction of the first light emission optical system 51R, the second light emission optical system 51G, and the third light emission optical system 51B is set to the opening 59H side of the cover 59.

In the present embodiment, as in the first embodiment, light is emitted so that the combined light forms a light distribution pattern of the low beam L in each of the diffraction grating 54R of the first light-emitting optical system 51R, the diffraction grating 54G of the second light-emitting optical system 51G, and the diffraction grating 54B of the third light-emitting optical system 51B.

That is, the first light L emitted from the diffraction grating 54R_RAnd second light L emitted from diffraction grating 54G_GAnd third light L emitted from diffraction grating 54B_BEach of the light beams is emitted from an opening 59H of the cover 59 and is irradiated to the outside of the vehicle headlamp via the front cover 12. In addition, the first 0 th order light LC emitted from the diffraction grating 54R_Rsecond 0 th-order light LC emitted from diffraction grating 54G_GThe third 0 th primary light LCB emitted from the diffraction grating 54B is emitted from the opening 59H of the cover 59 and is irradiated to the outside of the vehicle headlamp via the front cover 12. At this time, the first light L_RThe second light L_GAnd the third light L_BThe light distribution patterns are irradiated so that the outer shapes of the light distribution patterns are substantially matched at a focal position separated from the vehicle by a predetermined distance. The distance from the vehicle is set to 25m, for example. In addition, the first 0 th order light LC_RSecond 0 th order light LC_GAnd third 0 th order light LC_BThe light distribution patterns are irradiated so that the outlines of the light distribution patterns are substantially matched within a range RNG that is a blind spot of a driver of the automobile. That is, in the present embodiment, as described above, the light emission directions of the first light emission optical system 51R, the second light emission optical system 51G, and the third light emission optical system 51B are finely adjusted so that the outer shapes are uniform.

According to the vehicle headlamp of the present embodiment, since the synthetic optical system 55 of the first embodiment is not used, a simple configuration can be provided. In addition, according to the vehicle headlamp 1 of the present embodiment, the same as the first embodiment, becauseSince 0-th light having a higher luminous intensity than that of the higher-order light after 1-th light is irradiated into the range RNG which is a blind spot of the driver of the automobile, the reduction of the driver's ability to attract attention can be suppressed. In addition, the first light L of the present embodiment_RSecond light L_GAnd the third light L_BAnd first 0 th order light LC_RSecond 0 th order light LC_GAnd third 0 th order light LC_BThe outer shapes of (2) tend to be slightly deviated from each other except for the above-mentioned focal position. However, the variation in the outer shape can be suppressed as compared with light obtained by incident white light on one diffraction grating. Therefore, according to the present embodiment, a vehicle headlamp that can be downsized and can suppress color bleeding can be realized.

in the first and second embodiments, the first light L emitting the red component is provided_REmits the second light L of the green component_GAnd third light L emitting a blue component_BThe third light-emitting optical system of (1). However, in the first and second embodiments, the light emitted from the light sources of the three light-emitting optical systems is not limited to red, green, and blue as long as the light has different predetermined wavelengths.

In addition, one or two light emitting optical systems may be provided. Further, the number of the light emitting optical systems may be three or more. In this case, for example, a fourth light-emitting optical system may be provided that emits light of a yellow component near the light L. In this case, the fourth light-emitting optical system can emit light of a yellow component near the light L in addition to the red, green, and blue light-emitting optical systems described above. In addition, when the light intensities of a part of the red, green, and blue colors are low, the fourth light emission optical system may emit light of the same color component as the color with low light intensity.

In the first and second embodiments, a white balance adjustment circuit may be further provided. The white balance adjustment circuit can achieve a desired white balance by controlling the total luminous flux amount of light emitted from the light source 52R of the first light-emitting optical system 51R, the total luminous flux amount of light emitted from the light source 52G of the second light-emitting optical system 51G, and the total luminous flux amount of light emitted from the light source 52B of the third light-emitting optical system 51B. For example, the light source may be switched to emit warm white light or blue white light within the scope of the regulations.

In the first embodiment, the first optical element 55f transmits the first light L_RAnd the second light L_GReflects to synthesize the first light L_RAnd the second light L_GThe second optical element 55s makes the first light L synthesized by the first optical element 55f_RAnd the second light L_GTransmits and reflects the third light L_BThereby synthesizing the first light L_Rthe second light L_GAnd the third light L_B. However, for example, the third light L may be combined with the first optical element 55f_BAnd the second light L_Gin the second optical element 55s, the third light L synthesized by the first optical element 55f is emitted_BAnd the second light L_GAnd the first light L_RAnd (4) synthesizing. In this case, the positions of the first light emission optical system 51R and the third light emission optical system 51B in the first embodiment are replaced. In this case, the third 0 th order light LC is combined with the first optical element 55f_BAnd second 0 th light LC_GIn the second optical element 55s, the third 0 th-order light LC synthesized by the first optical element 55f_Band second 0 th order light LC_GAnd first 0 th order light LC_RAnd (4) synthesizing. In the first embodiment, a band-pass filter that transmits light in a predetermined wavelength band and reflects light in another wavelength band may be used for the first optical element 55f and the second optical element 55 s. The combining optical system 55 may be combined by combining the outer shapes of the lights emitted from the respective light emitting optical systems, and is not limited to the first embodiment.

In the first embodiment, the 0 th order light LC which travels straight through the diffraction gratings 54R, 54G, and 54B and passes therethrough is the 0 th order light LC_R、LC_G、LC_BSynthesized by the synthesizing optical system 55Projected onto the projection area AR. However, 0 th order light LC_R、LC_G、LC_BThe images can be projected to different regions in the range RNG which is a blind spot of the driver of the automobile without being synthesized by the synthesizing optical system 55. However, as described above, in the case of reducing the possibility that pedestrians and the like outside the vehicle are unnecessarily aware of the projection area AR, it is preferable that the 0 th-order light LC which travels straight and transmits through the respective diffraction gratings 54R, 54G, and 54B_R、LC_G、LC_BSynthesized by the synthesizing optical system 55 and projected onto the projection area AR.

In the first and second embodiments, a light distribution pattern of the low beam L is formed as a light distribution pattern for dark illumination. However, the light distribution pattern for dark illumination is not limited to the light distribution pattern of the low beam L. Further, the light distribution pattern for dark illumination is used in dark places such as nighttime and tunnels. For example, a light distribution pattern of the low beam L and a light distribution pattern of the marker visual recognition light located outside the light distribution pattern, for example, above the light distribution pattern may be formed as a light distribution pattern for dark illumination. In this case, it is preferable that the high-order diffracted light diffracted by the diffraction gratings 54R, 54G, and 54B include light for visual confirmation of the marker. Further, for example, a light distribution pattern of high beam may be formed as a light distribution pattern for dark illumination.

In the first and second embodiments, the vehicle headlamp 1 is exemplified by an automotive headlamp. However, the first and second embodiments are not limited to the headlamps of the automobile, and may be headlamps of other vehicles. The first and second embodiments are not limited to headlamps, but may be lamps such as back lamps, tail lamps, brake lamps, and indicator lamps.

In short, the present invention exemplified in the first and second embodiments may be any vehicle lamp as follows. That is, the vehicle lighting fixture includes a light source and a diffraction grating that diffracts light incident from the light source. The light diffracted by the diffraction grating is irradiated with a predetermined light distribution pattern, and a projection region projected by a component which is transmitted while traveling straight through the diffraction grating in the light incident on the diffraction grating is located below the light distribution pattern, and the field of view of the driver of the vehicle is located within a range blocked by the vehicle. As long as such a vehicle lamp is used, driving can be facilitated.

(third embodiment)

Next, a third embodiment of the present invention will be explained. The same or equivalent components as those in the first embodiment are denoted by the same reference numerals and redundant description thereof is omitted unless otherwise specified. Fig. 6 is a schematic cross-sectional view showing a vehicle including the vehicle headlamp of the present embodiment. As shown in fig. 6, the vehicle headlamp 1 of the present embodiment differs in that it includes an optical element 60.

The optical system unit 50 of the present embodiment includes a first light-emitting optical system 51R, a second light-emitting optical system 51G, a third light-emitting optical system 51B, a combining optical system 55, a cover 59, and an optical element 60.

The optical element 60 is an optical element that reduces the energy density of light. Examples of the optical element 60 include a light shielding element and a light diffusing element. Specific examples of the light-shielding member include members obtained by subjecting a metal plate such as aluminum to black anodizing or molding a light-shielding material such as carbon black and a base material. Specific examples of the light diffusing element include a lens and a sheet that diffuse or scatter light.

The optical element 60 is disposed on the optical path of the 0-order light beam LC between the projection area of the 0-order light beam LC and the diffraction gratings 54R, 54G, and 54B. The optical element 60 of the present embodiment is disposed in the housing 10. In the example shown in fig. 6, the optical element 60 is disposed on the lamp room R side surface of the front cover 12, and the distance of the optical path between the optical element 60 and the diffraction grating 54B closest to the optical element 60 is, for example, 100 mm.

Next, light emission from the vehicle headlamp 1 of the present embodiment will be described.

As in the first embodiment, first, power is supplied from a power supply not shown, and laser light is emitted from each of the light sources 52R, 52G, and 52B. As described above, the red laser beam is emitted from the light source 52R, and the green laser beam is emitted from the light source 52GThe colored laser beam is emitted from the light source 52B as a blue laser beam. The respective laser beams are collimated by the collimator lenses 53R, 53G, and 53B, and then enter the diffraction gratings 54R, 54G, and 54B. Then, as described above, the respective laser beams are diffracted by the diffraction gratings 54R, 54G, and 54B, and the first light L, which is the light of the red component of the light distribution pattern of the low beam L, is emitted from the first light-emitting optical system 51R_RSecond light L, which is a green component of the light distribution pattern of the low beam L, is emitted from the second light-emitting optical system 51G_GThird light L, which is a blue component of the light distribution pattern of the low beam L, is emitted from the third light-emitting optical system 51B_B. As described above, the first 0 th light LC of the 0 th light as the red component is emitted from the first light-emitting optical system 51R as the 0 th light which is transmitted in the diffraction gratings 54R, 54G, and 54B in a straight line manner_RSecond 0 th light LC which is 0 th light of green component emitted from the second light-emitting optical system 51G_GThird 0 th light LC which is 0 th light of blue component emitted from the third light emission optical system 51B_B。

In the combining optical system 55, first, the first light L_RAnd the second light L_GSynthesized and emitted by the first optical element 55f, and the first 0 th-order light LC_Rand second 0 th light LC_GSynthesized by the first optical element 55f and emitted. The first light L synthesized by the first optical element 55f_RAnd the second light L_GThe second optical element 55s and the third light L_BThe first 0 th light LC synthesized by the first optical element 55f_RAnd second 0 th light LC_GThe second optical element 55s and the third 0-th light LC_BAnd (4) synthesizing. At this time, the respective lights L_R、L_G、L_BIs the same as the low beam L, so the respective beams LR, L_G、L_BAre uniformly synthesized with each other. In addition, each 0 th order light LC_R、LC_G、LC_BIs also processed in the same way, so that each 0 th order light LC_R、LC_G、LC_BAre uniformly synthesized with each other. That is, the positions of the light-emitting optical systems and the combining optical system are finely adjusted so that the first light L is emitted_RSecond light L_GOf (2) isAnd the third light L_BAnd first 0 th order light LC_RSecond 0 th order light LC_GAnd third 0 th order light LC_BThe outer shape of (2) is combined by the synthesizing optical system as described above.

Thus, the first light L of red color_Rgreen second light L_GAnd blue third light L_BThe combined light becomes white, and the white light is emitted from the combining optical system 55 as low beam L. In addition, the first 0 th order light LC of red_RGreen second 0 th light LC_GAnd blue third 0 th light LC_BThe combined light becomes white, and the white light is emitted from the combining optical system 55 as the 0-order light beam LC.

The 0-order light beam LC emitted from the combining optical system 55 is emitted from the opening 59H of the cover 59, and is irradiated to the optical element 60 attached to the lamp room R side surface of the front cover 12, and the energy density of the 0-order light beam LC is reduced by the optical element 60.

the low beam L emitted from the combining optical system 55 is emitted from the opening 59H of the cover 59, is emitted from the vehicle headlamp 1 toward the front of the vehicle through the front cover 12, and is irradiated with a predetermined light distribution pattern. In the present embodiment, the light distribution pattern PTN of the low beam L shown in fig. 3 is used_LAnd (4) irradiating.

As described above, the vehicle headlamp 1 of the present embodiment includes the light sources 52R, 52G, and 52B and the diffraction gratings 54R, 54G, and 54B that diffract the light incident from the light sources 52R, 52G, and 52B. Among the light beams emitted from the diffraction gratings 54R, 54G, and 54B, the high-order diffracted light beams diffracted by the diffraction gratings 54R, 54G, and 54B form a light distribution pattern PTN of the low beam L_LAnd (4) irradiating.

In addition, the vehicle headlamp 1 of the present embodiment includes the optical element 60. The optical element 60 is disposed on the optical path of the 0-order light beam LC between the projection area of the 0-order light beam LC and the diffraction gratings 54R, 54G, and 54B, and reduces the energy density of the 0-order light beam LC.

Therefore, in the vehicle headlamp 1 according to the present embodiment, even if the light intensity of 0 th order light is higher than the light intensity of high order diffracted light among the light beams emitted from the diffraction gratings 54R, 54G, and 54B, the light intensity can be reduced by the optical element 60Energy density of 0 th order light. Therefore, the light distribution pattern PTN under higher-order diffracted light than in the light emitted from the diffraction gratings 54R, 54G, and 54B can be suppressed_LThe projected area of 0 th light becomes significantly brighter. As described above, the vehicle headlamp 1 according to the present embodiment can be driven more easily than a case without the optical element 60.

In the case of the present embodiment, as described above, the optical element 60 is disposed in the housing 10. Therefore, 0-time light emission to the outside of the vehicle is reduced. Therefore, the projection area of the 0 th-order light beam LC can be suppressed from becoming significantly bright outside the vehicle, and as a result, the driver, the pedestrian, or the like can be suppressed from being unnecessarily aware of the projection area.

In the case of the present embodiment, as described above, the optical element 60 may be a light blocking element or a light diffusing element. Therefore, in the vehicle headlamp 1 of the present embodiment, the light blocking element or the light diffusing element can be selected as the optical element 60 according to the vehicle type or the like on which the vehicle headlamp 1 is mounted.

In the present embodiment, the light distribution pattern PTN having the projection area positioned at the low beam L_Loutside of (a). In this case, the light distribution pattern PTN located at the low beam L from the projection area_LThe light distribution pattern PTN can be suppressed as compared with the case of_LA part of the light-emitting element becomes bright, and as a result, the driving can be facilitated.

The vehicle headlamp 1 of the present embodiment includes a plurality of light emitting optical systems each including one light source and one diffraction grating. That is, the vehicle headlamp 1 has a first light-emitting optical system 51R including one light source 52R and one diffraction grating 54R, a second light-emitting optical system 51G including one light source 52G and one diffraction grating 54G, and a third light-emitting optical system 51B including one light source 52B and one diffraction grating 54B. In addition, the vehicle headlamp 1 of the present embodiment further includes a combining optical system 55 that combines the lights emitted from the respective light emitting optical systems 51R, 51G, and 51B. The light sources 52R, 52G, and 52B emit light beams having different predetermined wavelengths, and the diffraction gratings 54R, 54G, and 54B convert the light beams combined by the combining optical system 55 into light beamsLight distribution pattern PTN of low beam L_LThe light from the light sources 52R, 52G, 52B is diffracted.

In this case, light of a predetermined wavelength emitted from the light sources 52R, 52G, and 52B is diffracted by the diffraction gratings 54R, 54G, and 54B to form the light distribution pattern PTN_L. At this time, in the respective light-emitting optical systems 51R, 51G, and 51B, since the light diffracted by the diffraction gratings 54R, 54G, and 54B has a predetermined wavelength, even if the diffraction gratings 54R, 54G, and 54B have wavelength dependency, the light distribution pattern PTN in the light emitted from the respective diffraction gratings 54R, 54G, and 54B can be suppressed_LProduces bleeding near the edge of the sheet. Having the light distribution pattern PTN in which the color bleeding is suppressed like this_LIs synthesized by the synthesizing optical system 55 to form a light distribution pattern PTN of a low beam L_L. Therefore, the low beam L emitted from the vehicle headlamp 1 of the present embodiment can be suppressed in the light distribution pattern PTN_LBleeding occurred near the edge of (a).

Therefore, the irradiation area of the 0 th order light irradiated to the optical element 60 can be reduced as compared with the case where the 0 th order light that travels straight and passes through the respective diffraction gratings 54R, 54G, and 54B is not combined. Therefore, the optical element 60 can suppress the energy density of the higher-order diffracted light in the light emitted from the diffraction gratings 54R, 54G, and 54B from being reduced.

(fourth embodiment)

Next, a fourth embodiment of the present invention will be described in detail with reference to fig. 7. The same or equivalent components as those in the third embodiment are denoted by the same reference numerals and redundant description thereof is omitted unless otherwise specified.

Fig. 7 is a view showing an optical system unit of the vehicle headlamp according to the present embodiment, similarly to fig. 2. As shown in fig. 7, the optical system unit 50 of the vehicle headlamp according to the present embodiment is different from the optical system unit 50 according to the third embodiment in that the synthesizing optical system 55 is not provided, and the lights emitted from the first light-emitting optical system 51R, the second light-emitting optical system 51G, and the third light-emitting optical system 51B are emitted from the cover 59 without being synthesized. In the present embodiment, the light emission direction of the first light emission optical system 51R, the second light emission optical system 51G, and the third light emission optical system 51B is set to the opening 59H side of the cover 59.

In the present embodiment, as in the third embodiment, light is emitted so that the combined light forms a light distribution pattern of the low beam L in each of the diffraction grating 54R of the first light-emitting optical system 51R, the diffraction grating 54G of the second light-emitting optical system 51G, and the diffraction grating 54B of the third light-emitting optical system 51B.

The optical system unit 50 of the vehicle headlamp is different from the optical system unit 50 of the third embodiment in that the optical elements 60A to 60C for reducing the energy density of 0 th-order light emitted from the first light-emitting optical system 51R, the second light-emitting optical system 51G, and the third light-emitting optical system 51B are provided instead of the optical elements 60. The optical element 60A is disposed on the first 0-th order light LC_RAnd the diffraction grating 54R, and the first 0 th order light LC between the projection area of_ROn the optical path of (a). In addition, the optical element 60B is disposed at the second 0 timesLight LC_GAnd the second 0 th order light LC between the diffraction grating 54G and the projection area of_GThe optical element 60C is disposed on the third 0-th light LC_BAnd the third 0 th-order light LC between the projection area of the diffraction grating 54B_BOn the optical path of (a). The optical elements 60A to 60C are disposed at positions corresponding to the first light L emitted from the diffraction grating 54R_RAnd second light L emitted from diffraction grating 54G_GAnd third light L emitted from diffraction grating 54B_BThe positions of overlap are also possible, but they may be non-overlapping positions. In the present embodiment, the optical elements 60A to 60C are disposed in the cover 59 and fixed to the cover 59 via a fixing tool not shown. The distance of the optical path between each of the optical elements 60A to 60C and the diffraction grating 54R is, for example, 100 mm. Therefore, it can be understood that the optical system unit 50 of the present embodiment has a larger configuration than the optical system unit 50 of the third embodiment.

According to the vehicle headlamp of the present embodiment, since the synthetic optical system 55 of the third embodiment is not used, a simple configuration can be provided. Even if the light intensity of 0 th order light is higher than the light intensity of the higher order diffracted light among the light beams emitted from the diffraction gratings 54R, 54G, and 54B, the energy density of the 0 th order light is reduced by the optical elements 60A to 60C. Therefore, the light distribution pattern PTN in the projection area of the 0 th order light can be suppressed from being lower than that in the higher order diffracted light in the same manner as in the third embodiment described above without using the synthesis optical system 55_LAnd is obviously brightened.

In the third and fourth embodiments, the first light L emitting the red component is provided_REmits the second light L of the green component_GAnd third light L emitting a blue component_Bthe third light-emitting optical system of (1). However, in the third and fourth embodiments, the light emitted from the light sources of the three light-emitting optical systems is not limited to red, green, and blue as long as the light has different predetermined wavelengths.

In addition, one or two light emitting optical systems may be provided. Further, the number of the light emitting optical systems may be three or more. In this case, a fourth light-emitting optical system may be provided that emits light of a yellow component near the light L. For example, the fourth light-emitting optical system may emit light of a yellow component near the light L, in addition to the red, green, and blue light-emitting optical systems described above. In addition, when the light intensities of a part of the red, green, and blue colors are low, the fourth light emission optical system may emit light of the same color component as the color with low light intensity.

In the third and fourth embodiments, a white balance adjustment circuit may be further provided. The white balance adjustment circuit can achieve a desired white balance by controlling the total luminous flux amount of light emitted from the light source 52R of the first light-emitting optical system 51R, the total luminous flux amount of light emitted from the light source 52G of the second light-emitting optical system 51G, and the total luminous flux amount of light emitted from the light source 52B of the third light-emitting optical system 51B. For example, the light source may be switched to emit warm white light or blue white light within the scope of the regulations.

In the third embodiment, the first optical element 55f transmits the first light L_RTransmits and transmits the second light L_GReflecting to combine the first light LR and the second light L_GThe second optical element 55s makes the first light L synthesized by the first optical element 55f_RAnd the second light L_GTransmits and reflects the third light L_BThereby synthesizing the first light L_RAnd the second light L_GAnd the third light L_B. However, for example, the third light L may be synthesized in the first optical element 55f_BAnd the second light L_GThe third light L synthesized by the first optical element 55f is combined in the second optical element 55s_BAnd the second light L_GAnd the first light L_RAnd (4) synthesizing. In this case, the positions of the first light emission optical system 51R and the third light emission optical system 51B in the third embodiment are replaced. In this case, the third 0 th order light LC is combined with the first optical element 55f_BAnd second 0 th light LC_GIn the second optical element 55s, the third 0 th-order light LC synthesized by the first optical element 55f_BAnd second 0 th order light LC_GAnd first 0 th order light LC_RAnd (4) synthesizing. In the third embodiment, a band-pass filter that transmits light in a predetermined wavelength band and reflects light in another wavelength band may be used for the first optical element 55f and the second optical element 55 s. The combining optical system 55 may be combined by combining the outer shapes of the lights emitted from the respective light emitting optical systems, and is not limited to the third embodiment.

in the third embodiment, the 0 th order light LC which travels straight and passes through the diffraction gratings 54R, 54G, and 54B is transmitted through the diffraction gratings 54R, 54G, and 54B_R、LC_G、LC_BEach region of the optical element 60 may be irradiated without being synthesized by the synthesizing optical system 55. However, as described above, when the irradiation area of the 0 th order light to the optical element 60 is reduced and the decrease of the energy density of the high-order diffracted light by the optical element 60 is suppressed, it is preferable that the 0 th order light LC which passes through the diffraction gratings 54R, 54G, and 54B straight is transmitted through the diffraction gratings 54R, 54G, and 54B_R、LC_G、LC_BSynthesized by the synthesizing optical system 55.

In the third and fourth embodiments, the light distribution pattern PTN having the projection area positioned at the low beam L is described_LBut may be located outside the light distribution pattern PTN_Land (4) the following steps. In this case, it is preferable that the light distribution pattern PTN of the low beam L_LAmong the light intensity distributions of the high-order diffracted lights diffracted by the diffraction gratings 54R, 54G, and 54B, the region having a light intensity equal to or less than half the maximum light intensity includes the projection region. In this way, as compared with a case where the projection region is included in a region higher than the half value of the maximum luminous intensity in the luminous intensity distribution of the high-order diffracted light, the luminous intensity distribution of the light distribution pattern can be formed more easily and smoothly with reference to the position at which the maximum luminous intensity is set in the luminous intensity distribution.

The optical element 60 according to the third and fourth embodiments may have zero energy density of the incident 0 th order light, or may emit the 0 th order light at an energy density smaller than the energy density of the incident 0 th order light. However, as described above, the light distribution pattern PTN located at the low beam L in the projection area_LIn the case of the above, it is preferable to use the light having a smaller energy density than the incident 0 th lightThe energy density of (2) is 0 th order light. Thus, even if 0 th order light is used as the light distribution pattern PTN of the low beam L_LAlso, the light distribution pattern PTN can be suppressed_LThe projected area of the middle 0 light becomes significantly brighter.

In the third and fourth embodiments, the light distribution pattern PTN of the low beam L is formed as the light distribution pattern for dark illumination_L. However, the light distribution pattern PTN is not limited to the light distribution pattern PTN of the low beam L as long as it is a light distribution pattern for illumination in a dark place_L. Further, the light distribution pattern for dark illumination is used in dark places such as nighttime and tunnels. For example, as shown in fig. 8, there is a light distribution pattern PTN for passing a low beam L_LAnd a light distribution pattern PTN provided on the light distribution pattern_LLight distribution pattern PTN of light for visual confirmation of outer, e.g., upper, sign_SWhen the light distribution pattern is formed for illumination in a dark place. In this case, it is preferable that the high-order diffracted light diffracted by the diffraction gratings 54R, 54G, and 54B include light for visual confirmation of the marker. Further, for example, as shown in fig. 9, there is a light distribution pattern PTN of high beam_HAnd is formed as a light distribution pattern for dark illumination. The light distribution pattern PTN of the high beam_HThe region HA1 in (a) is the region with the highest luminosity and the region HA2 is the region with a lower luminosity than the region HA 1. That is, the diffraction gratings 54R, 54G, and 54B form the light distribution pattern PTN including the luminous intensity distribution of the high beam with the combined light_HDiffracts the light.

In the third and fourth embodiments, the vehicle headlamp 1 is exemplified by an automobile headlamp. However, the third and fourth embodiments are not limited to the headlamps of the automobile, and may be headlamps of other vehicles. The third and fourth embodiments are not limited to headlamps, but may be lamps such as back lamps, tail lamps, brake lamps, and indicator lamps.

In short, the present invention exemplified in the third and fourth embodiments may be any vehicle lamp as follows. That is, the vehicle lighting fixture includes a light source, a diffraction grating that diffracts light incident from the light source, and an optical element that is disposed on an optical path of a light component between a projection area of the light component that travels straight through the diffraction grating and reduces the energy density of the light. Among the light beams emitted from the diffraction grating, the light beam diffracted by the diffraction grating is irradiated with a predetermined light distribution pattern. As long as such a vehicle lamp is used, driving can be facilitated.

(fifth embodiment)

Next, a fifth embodiment of the present invention will be explained. The same or equivalent components as those in the first embodiment are denoted by the same reference numerals and redundant description thereof is omitted unless otherwise specified. Fig. 10 is a schematic cross-sectional view showing a vehicle including the vehicle headlamp of the present embodiment. Fig. 11 is an enlarged view of an optical system unit of the vehicle headlamp of fig. 10. As shown in fig. 10 and 11, the configuration of the vehicle headlamp 1 according to the present embodiment is the same as the configuration of the vehicle headlamp 1 according to the first embodiment, but the light distribution pattern of the light emitted from the vehicle headlamp 1 according to the present embodiment is different from the light distribution pattern of the light emitted from the vehicle headlamp 1 according to the first embodiment.

The diffraction grating 54R of the present embodiment diffracts the laser light incident from the collimator lens 53R so as to form a predetermined light distribution pattern. Specifically, the diffraction grating 54R diffracts the laser light incident from the collimator lens 53R so that the light emitted from each of the first, second, and third light-emitting optical systems 51R, 51G, and 51B in the combining optical system 55 described below becomes a light distribution pattern of the diffracted light beam LD. The light distribution pattern also includes a luminous intensity distribution. Therefore, the diffraction grating 54R of the present embodiment diffracts the laser light incident from the collimator lens 53R so that the light diffracted by the diffraction grating 54R has the same outer shape as the outer shape of the light distribution pattern of the diffracted light beam LD and has the light intensity distribution based on the light intensity distribution of the light distribution pattern of the diffracted light beam LD.

The light diffracted by the diffraction grating 54R is high-order diffracted light having an order of 1 or more, and 0-order light which is not diffracted by the diffraction grating 54R but passes straight is emitted from the diffraction grating 54R in addition to the high-order diffracted light. In the present embodiment, 0 th-order light is emitted from the diffraction grating 54R such that the projection area of the 0 th-order light beam LC emitted from the combining optical system 55 described later is positioned within the light distribution pattern of the low beam L formed by the 0 th-order light beam LC and the diffracted light beam LD.

Thus, the first light-emitting optical system 51R emits high-order diffracted light of the red component in the low beam L, and emits 0-order light of the red component in the 0-order beam LC. In the present embodiment, the high-order diffracted light of the red component emitted from the first light-emitting optical system 51R is referred to as the first light LD_RThe 0 th order light of the red component is set as the first 0 th order light LC_R。

the diffraction grating 54G diffracts the laser light incident from the collimator lens 53G so as to form a predetermined light distribution pattern, and the diffraction grating 54B diffracts the laser light incident from the collimator lens 53B so as to form a predetermined light distribution pattern. Specifically, the diffraction gratings 54G and 54B diffract the laser beams incident from the collimator lenses 53G and 53B, respectively, so that the light emitted from the first light-emitting optical system 51R, the second light-emitting optical system 51G, and the third light-emitting optical system 51B in the combining optical system 55 becomes a light distribution pattern of the diffracted light beam LD. As described above, the light distribution pattern also includes the light intensity distribution. Therefore, the diffraction gratings 54G and 54B of the present embodiment diffract the laser beams incident from the collimator lenses 53G and 53B, respectively, so that the laser beams emitted from the diffraction gratings 54G and 54B have the same outer shape as the outer shape of the light distribution pattern of the diffracted light beam LD and have the light intensity distribution based on the light intensity distribution of the light distribution pattern of the diffracted light beam LD.

Thus, the second light-emitting optical system 51G emits high-order diffracted light of the green component in the low beam L, and emits 0-order light of the green component in the 0-order beam LC. In addition, the third light-emitting optical system 51B emits high-order diffracted light of the blue component in the low beam L, and emits 0-order light of the blue component in the 0-order beam LC. In the present embodiment, the high-order diffracted light of the green component emitted from the second light-emitting optical system 51G is the second light LD_GThe 0 th light of the green component is set as the second 0 th light LC_GThe third light LD is a high-order diffraction light of the blue component emitted from the third light-emitting optical system 51B_BThe 0 th order light of the blue component is set as the third 0 th order light LC_B. Therefore, in the present embodiment, the first light LD_RHas the longest wavelength, and the second light LD_GAnd the third light LD_BSuccessively shorter. Also, the first 0 th order light LC_RHas the longest wavelength of (1), and second 0 th order light LC_GThird 0 th order light LC_BSuccessively shorter.

the light intensity distribution based on the light intensity distribution of the light distribution pattern of the diffracted light beam LD is such that the light intensities of the respective high-order diffracted lights emitted from the diffraction gratings 54R, 54G, and 54B are high also in the portions of the light distribution pattern of the diffracted light beam LD having high light intensities.

The synthesizing optical system 55 has a first optical element 55f and a second optical element 55 s. The first optical element 55f is a first light LD to be emitted from the first light-emitting optical system 51R_RAnd second light LD emitted from second light-emitting optical system 51G_GA resultant optical element. The first optical element 55f is also the first 0-th order light LC to be emitted from the first light-emitting optical system 51R_RAnd from the second light-emitting optical system 5Second 0 th order light LC emitted from 1G_Ga resultant optical element. In the present embodiment, the first optical element 55f is configured to convert the first light LD_RTransmits and transmits the second light LD_GReflect to thereby convert the first light LD_RAnd a second light LD_GSynthesizing to make the first 0 th light LC_RTransmits and LC the second 0 th light_GReflect to thereby mix the first 0 th order light LC_RAnd second 0 th light LC_GAnd (4) synthesizing.

Second optical element 55s is first light LD to be combined by first optical element 55f_RAnd a second light LD_GAnd third light LD emitted from third light-emitting optical system 51B_BA resultant optical element. The second optical element 55s is also the first 0 th order light LC to be combined by the first optical element 55f_RAnd second 0 th order light LC_GAnd third 0-th light LC emitted from third light-emitting optical system 51B_BA resultant optical element. In the present embodiment, the second optical element 55s is configured to combine the first light LD combined by the first optical element 55f_RAnd a second light LD_GTransmits and transmits the third light LD_BReflect to thereby convert the first light LD_RAnd a second light LD_GAnd the third light LD_BAnd (4) synthesizing. The second optical element 55s is configured to combine the first 0 th order light LC combined by the first optical element 55f_RAnd second 0 th order light LC_GTransmits and LC third 0 th light_BReflect to thereby mix the first 0 th order light LC_RAnd second 0 th light LC_GAnd third 0 th light LC_BAnd (4) synthesizing.

Thus, the first light LD is emitted from the combining optical system 55_RA second light LD_GAnd the third light LD_BSynthesized to emit diffracted light beam LD, first 0-th order light LC_RSecond 0 th order light LC_GAnd third 0 th light LC_Band synthesized to emit 0-time beam LC.

Next, the emission of light by the vehicle headlamp 1 of the present embodiment will be described.

First, laser light is emitted from the light sources 52R, 52G, and 52B by supplying power from a power supply not shown. As described above, the red laser beam is emitted from the light source 52R, the green laser beam is emitted from the light source 52G, and the blue laser beam is emitted from the light source 52B. The respective laser beams are collimated by the collimator lenses 53R, 53G, and 53B, and then enter the diffraction gratings 54R, 54G, and 54B. Then, as described above, the respective laser beams are diffracted by the diffraction gratings 54R, 54G, and 54B, the first light LDR as the red component of the diffracted beam LD is emitted from the first light emitting optical system 51R, and the second light LD as the green component of the diffracted beam LD is emitted from the second light emitting optical system 51G_GThird light LD emitted from third light-emitting optical system 51B as a blue component of diffracted light LD_B. As described above, the first 0 th order light LC as the red component of the 0 th order light beam LC is emitted from the first light emission optical system 51R while passing through the diffraction gratings 54R, 54G, and 54B in a straight line, respectively_RSecond 0 th order light LC as the green component of the 0 th order light beam LC is emitted from the second light emission optical system 51G_GThird 0-order light LC as a blue component of the 0-order light beam LC is emitted from the third light emission optical system 51B_B。

In the combining optical system 55, first, the first light LD_RAnd a second light LD_GSynthesized and emitted by the first optical element 55f, and the first 0 th-order light LC_RAnd second 0 th light LC_GSynthesized by the first optical element 55f and emitted. First light LD synthesized by first optical element 55f_RAnd a second light LD_GSecond optical element 55s and third light LD_BThe first 0 th light LC synthesized by the first optical element 55f_RAnd second 0 th light LC_GThe second optical element 55s and the third 0-th light LC_Band (4) synthesizing. At this time, each light LD_R、LD_G、LD_BThe profile is set to be the same as that of the diffracted light beam LD, and thus each light beam LD_R、LD_G、LD_BAre uniformly synthesized with each other. In addition, each 0 th order light LC_R、LC_G、LC_BIs also processed in the same way, so that each 0 th order light LC_R、LC_G、LC_BAre uniformly synthesized with each other. That is, the positions of the light emitting optical systems and the combining optical system are finely adjusted so that the first light LD can be controlled_ROuter shape of, the second light LD_GAnd the third light LD_BAnd first 0 th order light LC_Rsecond 0 th order light LC_GAnd third 0 th order light LC_BThe outer shape of (2) is combined by the synthesizing optical system as described above.

Thus, the first light LD of red color_RGreen second light LD_GAnd blue third light LD_BThe combined light becomes white, and the white light is emitted from the combining optical system 55 as a diffracted light beam LD. In addition, the first 0 th order light LC of red_RGreen second 0 th light LC_GAnd blue third 0 th light LC_BThe combined light becomes white, and the white light is emitted from the combining optical system 55 as the 0-order light beam LC.

The diffracted light beam LD and the 0-order light beam LC emitted from the combining optical system 55 are emitted from the opening 59H of the cover 59 and emitted from the vehicle headlamp 1 to the front of the vehicle through the front cover 12. A light distribution pattern of low beam L is formed by diffracted beam LD and 0-order beam LC in front of the vehicle.

Fig. 12 is a diagram showing the light distribution pattern of the low beam and the luminous intensity distribution of the light distribution pattern in the present embodiment. As shown in fig. 12, the light distribution pattern PTN of the low beam L_LThe luminous intensity of the first region LA1, the second region LA2, and the third region LA3 is reduced in the order of LA1, LA2, and LA 3.

The first area LA1 is an area having a luminous intensity higher than the first luminous intensity threshold in the luminous intensity distribution of the diffracted light beam LD which is the high-order diffracted light, and the first area LA1 includes the highest luminous intensity L in the luminous intensity distribution of the diffracted light beam LD_HSite P of (a). The second area LA2 is an area having a luminous intensity equal to or lower than a first luminous intensity threshold and higher than a second luminous intensity threshold set to be lower than the first luminous intensity threshold in the luminous intensity distribution of the diffracted light beam LD, and the third area LA3 is an area having a luminous intensity of the diffracted light beam LDA region in the distribution that is below the second photometric threshold. The first luminosity threshold is set to, for example, the highest luminosity L in the luminosity distribution of the diffracted light beams LD_HHalf value of (c).

Such a light distribution pattern PTN of the low beam L_LThe projection area PAR of 0 th light irradiated by the 0 th light beam LC is located in the first area LA1 and is located in the hot zone HZ narrower than the first area LA 1. However, the projection area PAR of the 0 th light is located in the light intensity distribution avoiding the diffracted light beam LD and becomes the highest light intensity L_HPosition of the site P. The illuminance of the projection area PAR is a sum of the illuminance of the diffracted light beam LD and the illuminance of the 0 th-order light beam LC. In the example shown in fig. 12, the illuminance of the projection area PAR is higher than the highest illuminance L in the illuminance distribution of the diffracted light beam LD_HHigher than, but may be higher than, the light intensity L_HPoor quality. For example, the light intensity L can be compared by not irradiating the projection area PAR with the diffracted light beam LD_HThe luminosity of the PAR in the projection area is reduced.

The light diffracted by the diffraction gratings 54R, 54G, and 54B is combined by a combining optical system 55, and is emitted from the combining optical system 55 as a diffracted light beam LD. The light beams that travel straight and pass through the diffraction gratings 54R, 54G, and 54B are combined by the combining optical system 55, and are emitted from the combining optical system 55 as the 0 th-order light beam LC. The diffracted light beam LD and the 0 th-order light beam LC form a light distribution pattern of the low beam L. As shown in fig. 12, the projection area PAR of the 0 th-order light beam LC in the light distribution pattern is located in the light intensity distribution of the diffracted light beam LD which is the high-order diffracted light and becomes higher than the maximum light intensity L_HIn the region of high half-value luminosity.

Therefore, even if 0 th order light having a higher luminous intensity than that of the high-order diffracted light is irradiated to the projection area PAR, the light distribution pattern PTN at the low beam L can be suppressed_LThe middle projection area PAR becomes significantly brighter. Therefore, the vehicle headlamp 1 according to the present embodiment is arranged such that the maximum luminous intensity L is obtained in the luminous intensity distribution of the diffracted beam LD with respect to the projection area PAR_HCan be driven more easily than in the case outside the region of high half-value luminous intensity.

In the present embodiment, the projection area PAR is located in the light intensity distribution avoiding the diffracted beam LD and has the highest light intensity L_HPosition of the site P. Thus, the light distribution pattern PTN of the diffracted light beam LD can be suppressed_LMiddle to maximum luminosity L_Hthe portion P of (A) is excessively brightened.

In addition, the projection area PAR is disposed in the hot zone HZ, so that the light distribution pattern PTN using the 0 th beam LC as the low beam L is used_LAlso, the light distribution pattern PTN can be suppressed_LThe projected area PAR in (1) becomes significantly brighter.

The vehicle headlamp 1 of the present embodiment includes a plurality of light emitting optical systems each including one light source and one diffraction grating. That is, the vehicle headlamp 1 has a first light-emitting optical system 51R including one light source 52R and one diffraction grating 54R, a second light-emitting optical system 51G including one light source 52G and one diffraction grating 54G, and a third light-emitting optical system 51B including one light source 52B and one diffraction grating 54B. In addition, the vehicle headlamp 1 of the present embodiment further includes a combining optical system 55 that combines the lights emitted from the respective light emitting optical systems 51R, 51G, and 51B. The light sources 52R, 52G, and 52B emit light beams having different predetermined wavelengths, and the diffraction gratings 54R, 54G, and 54B form a light distribution pattern PTN in which the light beams combined by the combining optical system 55 have the low beam L_LThe light from the light sources 52R, 52G, and 52B is emitted.

In this case, light of a predetermined wavelength emitted from the light sources 52R, 52G, and 52B forms the light distribution pattern PTN by the diffraction gratings 54R, 54G, and 54B_L. At this time, in the respective light-emitting optical systems 51R, 51G, and 51B, since the light diffracted by the diffraction gratings 54R, 54G, and 54B has a predetermined wavelength, even if the diffraction gratings 54R, 54G, and 54B have wavelength dependency, the light distribution pattern PTN in the light emitted from the respective diffraction gratings 54R, 54G, and 54B can be suppressed_LProduces bleeding near the edge of the sheet. The light having the light distribution pattern PTNL with the color bleeding suppressed in this manner is synthesized by the synthesizing optical system 55 to form a near fieldLight distribution pattern PTN of light L_L. Therefore, the low beam L emitted from the vehicle headlamp 1 of the present embodiment can suppress the light distribution pattern PTN_LBleeding occurred near the edge of (a).

In the vehicle headlamp 1 according to the present embodiment, the 0 th order light LC that travels straight through the diffraction gratings 54R, 54G, and 54B and is transmitted therethrough_R、LC_G、LC_BSynthesized by the synthesizing optical system 55 and irradiated to the projection area PAR. In this case, as described above, even if the diffraction gratings 54R, 54G, and 54B have wavelength dependency, the 0 th order light LC transmitted through the respective diffraction gratings 54R, 54G, and 54B can be caused to pass through_R、LC_G、LC_BThe color is white. Therefore, in the vehicle headlamp 1 of the present embodiment, it is possible to reduce the driver from unnecessarily recognizing the projection area PAR, and to make driving easier.

(sixth embodiment)

Next, a sixth embodiment of the present invention will be described in detail with reference to fig. 13. The same or equivalent components as those in the fifth embodiment are denoted by the same reference numerals and redundant description thereof is omitted unless otherwise specified.

Fig. 13 is a view showing an optical system unit of the vehicle headlamp of the present embodiment, similarly to fig. 11. As shown in fig. 13, an optical system unit 50 of a vehicle headlamp according to the present embodiment is different from the optical system unit 50 according to the fifth embodiment in that a combining optical system 55 is not provided, and lights emitted from a first light-emitting optical system 51R, a second light-emitting optical system 51G, and a third light-emitting optical system 51B are emitted from a cover 59 without being combined. In the present embodiment, the light emission direction of the first light emission optical system 51R, the second light emission optical system 51G, and the third light emission optical system 51B is set to the opening 59H side of the cover 59.

In the present embodiment, as in the fifth embodiment, light is emitted so that the combined light forms a light distribution pattern of the low beam L in each of the diffraction grating 54R of the first light-emitting optical system 51R, the diffraction grating 54G of the second light-emitting optical system 51G, and the diffraction grating 54B of the third light-emitting optical system 51B.

That is, the first light LD emitted from the diffraction grating 54R_RAnd a second light LD emitted from the diffraction grating 54G_GAnd third light LD emitted from diffraction grating 54B_BEach of the light beams is emitted from an opening 59H of the cover 59 and is irradiated to the outside of the vehicle headlamp via the front cover 12. In addition, the first 0 th order light LC emitted from the diffraction grating 54R_RSecond 0 th-order light LC emitted from diffraction grating 54G_GAnd third 0 th order light LC emitted from diffraction grating 54B_BEach of the light beams is emitted from an opening 59H of the cover 59 and is irradiated to the outside of the vehicle headlamp via the front cover 12. At this time, the first light LD_RA second light LD_GAnd a third light LD_BAnd first 0 th order light LC_RSecond 0 th order light LC_GAnd third 0 th order light LC_BThe light distribution patterns are irradiated so that the outer shapes of the light distribution patterns are substantially matched at a focal position separated from the vehicle by a predetermined distance. The distance from the vehicle is set to 25m, for example. Therefore, a light distribution pattern of the low beam L is formed at a position separated from the vehicle by a predetermined distance. The light distribution pattern is a light distribution pattern PTN shown in fig. 12_LHaving the same photometric distribution as that shown in fig. 12. Therefore, as in the fifth embodiment, the light distribution pattern PTN_LThe projection area PAR of the middle 0 th order light is located in the light intensity distribution of the diffracted light beam LD as the high-order diffracted light and becomes higher than the maximum light intensity L_HIn the region of high half-value luminosity.

According to the vehicle headlamp of the present embodiment, the synthesizing optical system 55 of the fifth embodiment is not used, and therefore, a simple configuration can be provided. In addition, according to the vehicle headlamp of the present embodiment, since the projection area PAR of the 0 th order light is located in the light intensity distribution of the high-order diffracted light, the light intensity is higher than the maximum light intensity L_HIn the high-half-value light intensity region, the projected area PAR can be suppressed from being significantly brightened, as in the fifth embodiment. In addition, the first optical LD of the present embodiment_ROuter shape of, the second light LD_GAnd the third light LD_BAnd first 0 th order light LC_RSecond 0 th order light LC_GAnd third 0 th order light LC_BIs located at the above-mentioned focal pointThe outer portions tend to slightly deviate from each other. However, the variation in the outer shape can be suppressed as compared with light obtained by incident white light on one diffraction grating. Therefore, according to the present embodiment, a vehicle headlamp that can be downsized and can suppress color bleeding can be realized.

In the fifth and sixth embodiments, the first light LD that emits the red component is provided_RAnd a second light LD emitting a green component_GAnd a third light LD emitting a blue component_Bthe third light-emitting optical system of (1). However, in the vehicle headlamps according to the fifth and sixth embodiments, the light emitted from the light sources included in the three light-emitting optical systems is not limited to red, green, and blue, as long as the light has predetermined wavelengths different from each other.

In the fifth and sixth embodiments, a white balance adjustment circuit may be further provided. The white balance adjustment circuit can achieve a desired white balance by controlling the total luminous flux amount of light emitted from the light source 52R of the first light-emitting optical system 51R, the total luminous flux amount of light emitted from the light source 52G of the second light-emitting optical system 51G, and the total luminous flux amount of light emitted from the light source 52B of the third light-emitting optical system 51B. For example, the light source may be switched to emit warm white light or blue white light within the scope of the regulations.

In the fifth embodiment, the first optical element 55f transmits the first light through the first light guide plateOptical LD_RAnd second light LD_GReflecting to synthesize the first light LD_RAnd a second light LD_GSecond optical element 55s combines first light LD obtained by first optical element 55f_RAnd a second light LD_GTransmits and reflects the third light LD_BThereby synthesizing the first light LD_RAnd a second light LD_GAnd the third light LD_B. However, for example, the third light LD may be combined with the first optical element 55f_BAnd a second light LD_GIn the second optical element 55s, the third light LDB and the second light LD combined by the first optical element 55f_GAnd the first light LD_RAnd (4) synthesizing. In this case, the positions of the first light emission optical system 51R and the third light emission optical system 51B in the fifth embodiment are replaced. In this case, the third 0 th order light LC is combined with the first optical element 55f_BAnd second 0 th light LC_GIn the second optical element 55s, the third 0 th-order light LC synthesized by the first optical element 55f_BAnd second 0 th order light LC_GAnd first 0 th order light LC_RAnd (4) synthesizing. In the fifth embodiment, a band-pass filter that transmits light in a predetermined wavelength band and reflects light in another wavelength band may be used for the first optical element 55f and the second optical element 55 s. The combining optical system 55 may be combined by combining the outer shapes of the lights emitted from the respective light emitting optical systems, and is not limited to the fifth embodiment.

In the fifth embodiment, the 0 th order light LC which travels straight through the diffraction gratings 54R, 54G, and 54B and is transmitted therethrough is the 0 th order light LC_R、LC_G、LC_BThe respective regions of the projection region PAR may be irradiated without being synthesized by the synthesizing optical system 55. However, as described above, in order to reduce the driver from being unnecessarily aware of the projection area PAR, it is preferable to combine the 0 th order light LC which travels straight through the respective diffraction gratings 54R, 54G, and 54B and passes therethrough_R、LC_G、LC_B。

In the fifth and sixth embodiments, the projection area PAR is located in the light intensity distribution avoiding the high-order diffracted light and has the highest light intensity L_HBut may also include the position of (a). In this case, the light distribution pattern PTN of the low beam L is determined whether the illuminance of the 0 th order light is large or not_LThe brightest areas in the array do not change substantially. Therefore, the light distribution pattern PTN of the low beam L can be formed more easily and smoothly with reference to the position of the maximum luminous intensity in the luminous intensity distribution of the diffracted light beam LD_LThe photometric distribution of (1). However, as described above, in order to suppress the light distribution pattern PTN of the diffracted light beam LD_LMiddle to maximum luminosity L_HThe portion P of (A) is excessively brightened, and the maximum luminous intensity L in the luminous intensity distribution of the diffracted light beam LD is preferably avoided_HThe position of (a).

In the fifth and sixth embodiments, the light distribution pattern PTN of the low beam L is formed as the light distribution pattern for dark illumination_L. However, if the light distribution pattern for dark illumination is used, the light distribution pattern is not limited to the light distribution pattern PTN of the low beam L alone_L. Further, the light distribution pattern for dark illumination is used in dark places such as nighttime and tunnels. For example, as shown in fig. 14, there is a light distribution pattern PTN of the low beam L_LAnd a light distribution pattern PTN provided on the light distribution pattern_LLight distribution pattern PTN of light for visual confirmation of outer, e.g., upper, sign_SAnd is formed into a light distribution pattern for dark illumination. In this case, it is preferable that the high-order diffracted light diffracted by the diffraction gratings 54R, 54G, and 54B include light for visual confirmation of the marker. Further, for example, a light distribution pattern of high beam may be formed as a light distribution pattern for dark illumination.

In the fifth and sixth embodiments, the vehicle headlamp 1 is exemplified by an automotive headlamp. However, the fifth and sixth embodiments are not limited to the headlamps of the automobile, and may be headlamps of other vehicles. The fifth and sixth embodiments are not limited to headlamps, but may be lamps such as back lamps, tail lamps, brake lamps, and indicator lamps.

In short, the present invention exemplified in the fifth and sixth embodiments may be any vehicle lamp as follows. That is, the vehicle lighting fixture includes a light source and a diffraction grating that diffracts light incident from the light source. The light diffracted by the diffraction grating and the light that travels straight through the diffraction grating form a light distribution pattern having a predetermined luminous intensity distribution. The projection region of the light that passes through the diffraction grating in a straight line in the light distribution pattern is located in a region having a luminous intensity higher than half the maximum luminous intensity in the luminous intensity distribution of the light diffracted by the diffraction grating. As long as such a vehicle lamp is used, driving can be facilitated.

(seventh embodiment)

Next, a seventh embodiment of the present invention will be explained. The same or equivalent components as those in the fifth embodiment are denoted by the same reference numerals and redundant description thereof is omitted unless otherwise specified. The configuration of the vehicle headlamp 1 in the present embodiment is the same as the configuration of the vehicle headlamp 1 in the fifth embodiment, but the light distribution pattern of the light emitted from the vehicle headlamp 1 in the present embodiment is different from the light distribution pattern of the light emitted from the vehicle headlamp 1 in the fifth embodiment.

The diffraction grating 54R of the present embodiment emits the laser light incident from the collimator lens 53R so as to form a predetermined light distribution pattern. Specifically, the diffraction grating 54R emits the laser light incident on the collimator lens 53R so that the light emitted from each of the first, second, and third light-emitting optical systems 51R, 51G, and 51B in the combining optical system 55 becomes a light distribution pattern of the diffracted light beam LD. The light distribution pattern also includes a luminous intensity distribution. Therefore, the diffraction grating 54R of the present embodiment emits the laser light incident from the collimator lens 53R so that the light diffracted by the diffraction grating 54R has the same outer shape as the outer shape of the light distribution pattern of the diffracted light beam LD and has the light intensity distribution based on the light intensity distribution of the light distribution pattern of the diffracted light beam LD.

The light diffracted by the diffraction grating 54R is high-order diffracted light having a frequency of 1 or more, and 0-order light which is not diffracted by the diffraction grating 54R but passes straight is emitted from the diffraction grating 54R in addition to the high-order diffracted light. In the present embodiment, 0-th order light is emitted from the diffraction grating 54R such that the projection area of the 0-th order light beam LC emitted from the combining optical system 55 is positioned within the light distribution pattern of the low beam L formed by the 0-th order light beam LC and the diffracted light beam LD. The diffraction grating 54R of the present embodiment emits the laser light incident from the collimator lens 53R so that the high-order diffracted light diffracted by the diffraction grating 54R in the projection area of the 0 th-order light beam LC becomes non-irradiation. Therefore, in the projection area of the 0 th order light flux LC in the light distribution pattern of the low beam L, the light intensity of the high order diffracted light diffracted by the diffraction grating 54R is zero.

Thus, the first light-emitting optical system 51R emits high-order diffracted light of the red component in the low beam L, and emits 0-order light of the red component in the 0-order beam LC. In the present embodiment, the high-order diffracted light of the red component emitted from the first light-emitting optical system 51R is referred to as the first light LD_RThe 0 th order light of the red component is set as the first 0 th order light LC_R。

The diffraction grating 54G emits the laser beam incident from the collimator lens 53G so as to form a predetermined light distribution pattern, and the diffraction grating 54B emits the laser beam incident from the collimator lens 53B so as to form a predetermined light distribution pattern. Specifically, the diffraction gratings 54G and 54B diffract the laser beams incident from the collimator lenses 53G and 53B, respectively, so that the light emitted from the first light-emitting optical system 51R, the second light-emitting optical system 51G, and the third light-emitting optical system 51B in the combining optical system 55 becomes a light distribution pattern of the diffracted light beam LD. As described above, the light distribution pattern also includes the light intensity distribution. Therefore, the diffraction gratings 54G and 54B of the present embodiment diffract the laser beams incident from the collimator lenses 53G and 53B, respectively, so that the laser beams emitted from the diffraction gratings 54G and 54B have the same outer shape as the outer shape of the light distribution pattern of the diffracted light beam LD and have the light intensity distribution based on the light intensity distribution of the light distribution pattern of the diffracted light beam LD.

The light diffracted by the diffraction grating 54G is high-order diffracted light having an order of 1 or more, and 0-order light which is not diffracted by the diffraction grating 54G but passes straight is emitted from the diffraction grating 54G in addition to the high-order diffracted light. In the present embodiment, 0 th-order light is emitted from the diffraction grating 54G so that the projection area of the 0 th-order light beam LC emitted from the combining optical system 55 is positioned within the light distribution pattern of the low beam L formed by the 0 th-order light beam LC and the diffracted light beam LD. The diffraction grating 54G of the present embodiment emits the laser light incident from the collimator lens 53G so that the high-order diffracted light diffracted by the diffraction grating 54G becomes non-irradiated in the projection area of the 0 th-order light beam LC. Therefore, in the projection area of the 0 th order light flux LC in the light distribution pattern of the low beam L, the light intensity of the high order diffracted light diffracted by the diffraction grating 54G is zero.

Similarly, the light diffracted by the diffraction grating 54B is high-order diffracted light having a frequency of 1 or more, and 0-order light which is not diffracted by the diffraction grating 54B but passes straight is emitted from the diffraction grating 54B in addition to the high-order diffracted light. In the present embodiment, 0 th order light is emitted from the diffraction grating 54B so that the projection area of the 0 th order light beam LC emitted from the combining optical system 55 is positioned within the light distribution pattern of the low beam L formed by the 0 th order light beam LC and the diffracted light beam LD. The diffraction grating 54B of the present embodiment emits the laser light incident from the collimator lens 53B so that the high-order diffracted light diffracted by the diffraction grating 54B is not irradiated in the projection area of the 0 th-order light beam LC. Therefore, in the projection area of the 0 th order light flux LC in the light distribution pattern of the low beam L, the light intensity of the high order diffracted light diffracted by the diffraction grating 54B is zero.

Thus, the second light-emitting optical system 51G emits high-order diffracted light of the green component in the low beam L, and emits 0-order light of the green component in the 0-order beam LC. In addition, the third light-emitting optical system 51B emits high-order diffracted light of the blue component in the low beam L, and emits 0-order light of the blue component in the 0-order beam LC. In the present embodiment, the high-order diffracted light of the green component emitted from the second light-emitting optical system 51G is the second light LD_GThe 0 th light of the green component is set as the second 0 th light LC_GThe third light LD is a high-order diffraction light of the blue component emitted from the third light-emitting optical system 51B_BThe 0 th order light of the blue component is set as the third 0 th order light LC_B. Therefore, in the present embodiment, the first light LD_RHas the longest wavelength, and the second light LD_GAnd the third light LD_BSuccessively shorter. Also, the first 0 th lightLC_RHas the longest wavelength of (1), and second 0 th order light LC_GThird 0 th order light LC_BSuccessively shorter.

Next, the emission of light by the vehicle headlamp 1 of the present embodiment will be described.

First, laser light is emitted from the light sources 52R, 52G, and 52B by supplying power from a power supply not shown. As described above, the red laser beam is emitted from the light source 52R, the green laser beam is emitted from the light source 52G, and the blue laser beam is emitted from the light source 52B. The respective laser beams are collimated by the collimator lenses 53R, 53G, and 53B, and then enter the diffraction gratings 54R, 54G, and 54B. Then, as described above, the respective laser beams are diffracted by the diffraction gratings 54R, 54G, and 54B, the first light LDR as the red component of the diffracted beam LD is emitted from the first light emitting optical system 51R, and the second light LD as the green component of the diffracted beam LD is emitted from the second light emitting optical system 51G_GThird light LD emitted from third light-emitting optical system 51B as a blue component of diffracted light LD_B. As described above, the first 0 th order light LC as the red component of the 0 th order light beam LC is emitted from the first light emission optical system 51R while passing through the diffraction gratings 54R, 54G, and 54B in a straight line, respectively_RSecond 0 th order light LC as the green component of the 0 th order light beam LC is emitted from the second light emission optical system 51G_GThird 0-order light LC as a blue component of the 0-order light beam LC is emitted from the third light emission optical system 51B_B。

in the combining optical system 55, first, the first light LD_RAnd a second light LD_GSynthesized and emitted by the first optical element 55f, and the first 0 th-order light LC_RAnd second 0 th light LC_GSynthesized by the first optical element 55f and emitted. First light LD synthesized by first optical element 55f_RAnd a second light LD_GSecond optical element 55s and third light LD_BThe first 0 th light LC synthesized by the first optical element 55f_RAnd second 0 th light LC_GThe second optical element 55s and the third 0-th light LC_BAnd (4) synthesizing. At this time, each light LD_R、LD_G、LD_BIs set to be the same as the outer shape of the diffracted light beam LD, and therefore eachSingle light LD_R、LD_G、LD_BAre uniformly synthesized with each other. In addition, each 0 th order light LC_R、LC_G、LC_BIs also processed in the same way, so that each 0 th order light LC_R、LC_G、LC_BAre uniformly synthesized with each other. That is, the positions of the light emitting optical systems and the combining optical system are finely adjusted so that the first light LD can be controlled_ROuter shape of, the second light LD_GAnd the third light LD_BAnd first 0 th order light LC_RSecond 0 th order light LC_GAnd third 0 th order light LC_Bthe outer shape of (2) is combined by the synthesizing optical system as described above.

Thus, the first light LD of red color_RGreen second light LD_GAnd blue third light LD_BThe combined light becomes white, and the white light is emitted from the combining optical system 55 as a diffracted light beam LD. In addition, the first 0 th order light LC of red_RGreen second 0 th light LC_GAnd blue third 0 th light LC_Bthe combined light becomes white, and the white light is emitted from the combining optical system 55 as the 0-order light beam LC.

Fig. 15 is a diagram showing a light distribution pattern of low beams and a luminous intensity distribution of the light distribution pattern according to the present embodiment. As shown in fig. 15, the light distribution pattern PTN of the low beam L_LThe luminous intensity of the first region LA1, the second region LA2, and the third region LA3 is reduced in the order of LA1, LA2, and LA 3.

The first area LA1 is an area having a luminous intensity higher than the first luminous intensity threshold in the luminous intensity distribution of the diffracted light beam LD which is the high-order diffracted light, and the first area LA1 includes the highest luminous intensity L in the luminous intensity distribution of the diffracted light beam LD_HSite P of (a). The second area LA2 is equal to or less than the first luminous intensity threshold value and higher than the set luminous intensity threshold value in the luminous intensity distribution of the diffracted light beam LDThe third area LA3 is an area of the luminous intensity distribution of the diffracted light beam LD that is equal to or lower than the second luminous intensity threshold, which is set to a luminous intensity area of the second luminous intensity threshold lower than the first luminous intensity threshold. The first luminosity threshold is set to, for example, the highest luminosity L in the luminosity distribution of the diffracted light beams LD_HHalf value of (c).

Such a light distribution pattern PTN of the low beam L_LThe projection area PAR of 0 th light irradiated by the 0 th light beam LC is included in the second area LA2 and overlaps with a part of the first area LA 1. In addition, the illuminance of the projection area PAR of the 0 th light is lower than the highest illuminance LH in the illuminance distribution of the diffracted light beam LD.

Fig. 16 is a diagram showing a light distribution pattern of the low beam L and a luminous intensity distribution of the light distribution pattern in the case where the 0-time light flux LC is not irradiated. As described above, in the present embodiment, since the light intensity of the high-order diffracted light irradiated to the projection area PAR of the 0 th order light is zero, as shown in fig. 16, when the 0 th order light beam LC is not irradiated, the light distribution pattern PTN of the low beam L_LThe projected area PAR of 0 light becomes a darker aperture. By irradiating the projection area PAR with the light beam LC 0 times, a light distribution pattern PTN of the low beam L shown in fig. 15 is formed_L. That is, the light intensity of the projection area PAR is the total value of the light intensity of the diffracted beam LD and the light intensity of the 0 th-order beam LC, but in the present embodiment, the light intensity of the high-order diffracted light irradiated to the projection area PAR is zero as described above, and therefore the light intensity of the projection area PAR matches the light intensity of the 0 th-order beam LC.

The light beams emitted from the diffraction gratings 54R, 54G, and 54B are combined by a combining optical system 55, and are emitted from the combining optical system 55 as a diffracted light beam LD and a 0-order light beam LC. A low beam L is obtained from the diffracted beam LD and the 0-order beam LC, and the low beam L has a light distribution pattern PTN with a prescribed luminous intensity distribution_LAnd (4) irradiating. In the light distribution pattern PTN_LIn the projection area PAR of 0 th light, the diffracted light beam LD is not irradiated. As described above, the diffracted beam LD is formed by the diffraction grating 54R,54G, 54B diffracted light of higher order.

Therefore, the light intensity of the high-order diffracted light in the projection area PAR is smaller than the light intensity of the light irradiated to the outer periphery of the projection area PAR. Therefore, even if 0 th order light having a higher luminous intensity than that of the high-order diffracted light is irradiated to the projection area PAR, the light distribution pattern PTN of the low beam L can be reduced_LThe projected area PAR in (1) becomes significantly brighter. Therefore, the vehicle headlamp 1 according to the present embodiment can be driven more easily than in the case where the light intensity of the high-order diffracted light in the projection area PAR is equal to or greater than the light intensity of the light irradiated to the outer peripheral edge of the projection area PAR.

In the case of the present embodiment, since the diffracted light beam LD is not irradiated to the projection area PAR as described above, the light intensity of the high-order diffracted light irradiated to the projection area PAR is zero. Therefore, in the present embodiment, even when the difference between the light intensity of the 0 th order light and the light intensity of the high-order diffracted light is large, the light distribution pattern PTN of the low beam L is reduced_LThe projection area PAR becomes remarkably bright, and the light distribution pattern PTN_LThe whole body is easy to form smooth luminosity distribution.

As described above, since the light intensity of the high-order diffracted light irradiated to the projection area PAR is zero, the light intensity of the projection area PAR becomes 0 th order light intensity. The luminous intensity of the 0 th order light is, as shown in FIG. 15, compared with the highest luminous intensity L in the luminous intensity distribution of the diffracted light LD as the higher-order diffracted light_HLow. Therefore, in the present embodiment, the highest luminous intensity L is obtained in the luminous intensity distribution of the high-order diffracted light_HEasily and smoothly forms a light distribution pattern PTN with reference to the portion P of (A)_LThe photometric distribution of (1).

In the case of the present embodiment, the light distribution pattern PTN of the low beam L_LHas a first area LA1, a second area LA2 of a lower illuminance than that of the first area LA1, and a third area LA3 of a lower illuminance than that of the second area LA 2. Also, the projected area PAR is contained within the second area LA2, and a part of the projected area PAR overlaps with the first area LA 1. Thus, the light distribution pattern PTN with the low beam L_LThe third area LA3, which is the area with the lowest luminous intensity, includes projectionThe light distribution pattern PTN of the low beam L can be reduced as compared with the case of the shadow area PAR_LThe projected area PAR in (1) becomes significantly brighter.

The vehicle headlamp 1 of the present embodiment includes a plurality of light emitting optical systems each including one light source and one diffraction grating. That is, the vehicle headlamp 1 has a first light-emitting optical system 51R including one light source 52R and one diffraction grating 54R, a second light-emitting optical system 51G including one light source 52G and one diffraction grating 54G, and a third light-emitting optical system 51B including one light source 52B and one diffraction grating 54B. In addition, the vehicle headlamp 1 of the present embodiment further includes a combining optical system 55 that combines the lights emitted from the respective light emitting optical systems 51R, 51G, and 51B. The light sources 52R, 52G, and 52B emit light beams having different predetermined wavelengths, and the diffraction gratings 54R, 54G, and 54B emit light beams from the light sources 52R, 52G, and 52B so that the light beams combined by the combining optical system 55 form a light distribution pattern of the low beam L.

In this case, light of a predetermined wavelength emitted from the light sources 52R, 52G, and 52B is diffracted by the diffraction gratings 54R, 54G, and 54B to form a light distribution pattern. At this time, in each of the light-emitting optical systems 51R, 51G, and 51B, since the light diffracted by the diffraction gratings 54R, 54G, and 54B has a predetermined wavelength, even if the diffraction gratings 54R, 54G, and 54B have wavelength dependency, it is possible to suppress occurrence of color bleeding in the vicinity of the edge of the light distribution pattern in the light emitted from each of the diffraction gratings 54R, 54G, and 54B. The light having the light distribution pattern in which the color bleeding is suppressed in this manner is synthesized by the synthesizing optical system 55 to form a light distribution pattern of the low beam L. Therefore, the low beam L emitted from the vehicle headlamp 1 of the present embodiment can suppress the occurrence of bleeding in the vicinity of the edge of the light distribution pattern.

In the vehicle headlamp 1 according to the present embodiment, the 0 th order light LC that travels straight through the diffraction gratings 54R, 54G, and 54B and is transmitted therethrough_R、LC_G、LC_BSynthesized by the synthesizing optical system 55 and irradiated to the projection area PAR. In this case, as described above, even if the diffraction gratings 54R, 54G, and 54B have wavelength dependency, the 0 th order light transmitted through the respective diffraction gratings 54R, 54G, and 54B can be transmittedLC_R、LC_G、LC_BThe color is white. Therefore, in the vehicle headlamp 1 of the present embodiment, it is possible to reduce the driver from unnecessarily recognizing the projection area PAR, and to make driving easier.

(eighth embodiment)

Next, an eighth embodiment of the present invention will be explained. The same or equivalent components as those in the seventh embodiment are denoted by the same reference numerals and redundant description thereof is omitted unless otherwise specified.

Since the drawings showing the optical system unit of the vehicle headlamp of the present embodiment are the same as those in fig. 13, the present embodiment will be described with reference to fig. 13. As shown in fig. 13, the optical system unit 50 of the vehicle headlamp according to the present embodiment is different from the optical system unit 50 according to the seventh embodiment in that the synthesizing optical system 55 is not provided, and the lights emitted from the first light-emitting optical system 51R, the second light-emitting optical system 51G, and the third light-emitting optical system 51B are emitted from the cover 59 without being synthesized. In the present embodiment, the light emission direction of the first light emission optical system 51R, the second light emission optical system 51G, and the third light emission optical system 51B is set to the opening 59H side of the cover 59.

In the present embodiment, as in the seventh embodiment, light is emitted so that the combined light forms a light distribution pattern of the low beam L in each of the diffraction grating 54R of the first light-emitting optical system 51R, the diffraction grating 54G of the second light-emitting optical system 51G, and the diffraction grating 54B of the third light-emitting optical system 51B.

That is, the first light LD emitted from the diffraction grating 54R_RAnd a second light LD emitted from the diffraction grating 54G_GAnd third light LD emitted from diffraction grating 54B_BEach of the light beams is emitted from an opening 59H of the cover 59 and is irradiated to the outside of the vehicle headlamp via the front cover 12. In addition, the first 0 th order light LC emitted from the diffraction grating 54R_RSecond 0 th-order light LC emitted from diffraction grating 54G_GAnd third 0 th order light LC emitted from diffraction grating 54B_BRespectively, are emitted from openings 59H of the cover 59, and are irradiated toward the front of the vehicle via the front cover 12The exterior of the lamp. At this time, the first light LD_RA second light LD_GAnd a third light LD_BAnd first 0 th order light LC_RSecond 0 th order light LC_Gand third 0 th order light LC_BThe light distribution patterns are irradiated so that the outer shapes of the light distribution patterns are substantially matched at a focal position separated from the vehicle by a predetermined distance. The distance from the vehicle is set to 25m, for example. Therefore, a light distribution pattern of the low beam L is formed at a position separated from the vehicle by a predetermined distance. The light distribution pattern is a light distribution pattern PTN shown in fig. 15_LAnd has the same photometric distribution as that shown in fig. 15. Therefore, as in the seventh embodiment, the diffracted light beam LD is not irradiated in the projection area PAR of the 0 th order light, and the light intensity of the high-order diffracted light in the projection area PAR is smaller than the light intensity of the light irradiated to the outer periphery of the projection area PAR.

According to the vehicle headlamp of the present embodiment, the synthesizing optical system 55 of the seventh embodiment is not used, and therefore, a simple configuration can be provided. In addition, according to the vehicle headlamp of the present embodiment, since the light intensity of the high-order diffracted light in the projection area PAR is smaller than the light intensity of the light irradiated to the outer peripheral edge of the projection area PAR, the light distribution pattern PTN can be reduced as in the seventh embodiment_LIn the case of a clearly brighter projected area PAR. In addition, the outer shape of the first light LDR and the second light LD in the present embodiment_GAnd the third light LD_BAnd first 0 th order light LC_RSecond 0 th order light LC_GAnd third 0 th order light LC_BThe outer shapes of (2) tend to be slightly deviated from each other except for the above-mentioned focal position. However, the variation in the outer shape can be suppressed as compared with light obtained by incident white light on one diffraction grating. Therefore, according to the present embodiment, a vehicle headlamp that can be downsized and can suppress color bleeding can be realized.

In the seventh and eighth embodiments, the first light LD that emits the red component is provided_RAnd a second light LD emitting a green component_GAnd a third light LD emitting a blue component_BThird of (2)A light emitting optical system. However, in the vehicle headlamps according to the seventh and eighth embodiments, the light emitted from the light sources included in the three light-emitting optical systems is not limited to red, green, and blue, as long as the light has predetermined wavelengths different from each other.

In the seventh and eighth embodiments, a white balance adjustment circuit may be further provided. The white balance adjustment circuit can achieve a desired white balance by controlling the total luminous flux amount of light emitted from the light source 52R of the first light-emitting optical system 51R, the total luminous flux amount of light emitted from the light source 52G of the second light-emitting optical system 51G, and the total luminous flux amount of light emitted from the light source 52B of the third light-emitting optical system 51B. For example, the light source may be switched to emit warm white light or blue white light within the scope of the regulations.

In the seventh embodiment, the first optical element 55f transmits the first light through the first light LD_RAnd second light LD_GReflecting to synthesize the first light LD_RAnd a second light LD_GSecond optical element 55s combines first light LD obtained by first optical element 55f_RAnd a second light LD_GTransmits and reflects the third light LD_BThereby synthesizing the first light LD_RAnd a second light LD_GAnd the third light LD_B. However, for example, the third light LD may be combined with the first optical element 55f_BAnd a second light LD_GIn the second optical element 55s, the third optical element 55f is combined with the first optical element 55fLight LDB and second light LD_GAnd the first light LD_RAnd (4) synthesizing. In this case, the positions of the first light emission optical system 51R and the third light emission optical system 51B of the seventh embodiment are replaced. In this case, the third 0 th order light LC is combined with the first optical element 55f_BAnd second 0 th light LC_GIn the second optical element 55s, the third 0 th-order light LC synthesized by the first optical element 55f_BAnd second 0 th order light LC_GAnd first 0 th order light LC_RAnd (4) synthesizing. In the seventh embodiment, a band-pass filter that transmits light in a predetermined wavelength band and reflects light in another wavelength band may be used for the first optical element 55f and the second optical element 55 s. The combining optical system 55 may be combined by combining the outer shapes of the lights emitted from the respective light emitting optical systems, and is not limited to the above-described embodiments.

In the seventh and eighth embodiments, the high-order diffracted light diffracted by the diffraction gratings 54R, 54G, and 54B and emitted from the diffraction gratings 54R, 54G, and 54B is not irradiated to the projection area PAR, and the light intensity of the high-order diffracted light is zero in the projection area PAR. However, if the light intensity of the high-order diffracted light irradiated to the projection area PAR is smaller than the light intensity of the light irradiated to the outer periphery of the projection area PAR, the light intensity of the high-order diffracted light irradiated to the projection area PAR may be larger than zero.

In the seventh embodiment, the 0 th order light LC which travels straight through the diffraction gratings 54R, 54G, and 54B and passes through them is_R、LC_G、LC_BThe respective regions of the projection region PAR may be irradiated without being synthesized by the synthesizing optical system 55. However, as described above, in order to reduce the driver from being unnecessarily aware of the projection area PAR, it is preferable to combine the 0 th order light LC which travels straight through the respective diffraction gratings 54R, 54G, and 54B and passes therethrough_R、LC_G、LC_B。

In the seventh and eighth embodiments, the projection area PAR overlaps with a part of the first area LA1, but may be included in the first area LA 1. The projection area PAR does not include high-order diffracted lightBecomes the highest luminosity L in the luminosity distribution_HBut may also include the location(s). In this case, the light distribution pattern PTN of the low beam L is determined whether the illuminance of the 0 th order light is large or not_LThe brightest areas in the array do not change substantially. Therefore, the light distribution pattern PTN of the low beam L can be formed more smoothly with reference to the position where the highest luminous intensity is obtained in the luminous intensity distribution of the high-order diffracted light_LThe photometric distribution of (1).

In the seventh and eighth embodiments, the illuminance of the projection area PAR is higher than the highest illuminance L in the illuminance distribution of the high-order diffracted light_HLow. However, the light intensity of the projection area PAR may be the highest light intensity L in the light intensity distribution of the higher-order diffracted light_HThe above. In this case, the projection area PAR is preferably included in the first area LA1, and the highest luminous intensity L in the luminous intensity distribution of the high-order diffracted light is more preferably set to the maximum luminous intensity L_HContains the projection area PAR.

in the seventh and eighth embodiments, the light distribution pattern PTN of the low beam L is formed as a light distribution pattern for dark illumination_L. However, if the light distribution pattern for dark illumination is used, the light distribution pattern is not limited to the light distribution pattern PTN of the low beam L alone_L. Further, the light distribution pattern for dark illumination is used in dark places such as nighttime and tunnels. For example, a light distribution pattern of the low beam L and a light distribution pattern of the marker visual recognition light located outside the light distribution pattern, for example, above the light distribution pattern may be formed as a light distribution pattern for dark illumination. In this case, it is preferable that the high-order diffracted light diffracted by the diffraction gratings 54R, 54G, and 54B include light for visual confirmation of the marker. Further, for example, a light distribution pattern of high beam may be formed as a light distribution pattern for dark illumination.

In the seventh and eighth embodiments, the vehicle headlamp 1 is exemplified by an automobile headlamp. However, the seventh and eighth embodiments are not limited to the headlamps of the automobile, and may be headlamps of other vehicles. The seventh and eighth embodiments are not limited to headlamps, but may be lamps such as back lamps, tail lamps, brake lamps, and indicator lamps.

In short, the present invention exemplified in the seventh and eighth embodiments may be any vehicle lamp as follows. That is, the vehicle lighting fixture includes a light source and a diffraction grating that diffracts light incident from the light source. The light emitted from the diffraction grating is irradiated with a light distribution pattern having a predetermined luminous intensity distribution. In the projection region of the light that passes through the diffraction grating in the light distribution pattern while traveling straight, the light intensity of the light that is diffracted by the diffraction grating and is irradiated onto the projection region is smaller than the light intensity of the light that is irradiated onto the outer periphery of the projection region. As long as such a vehicle lamp is used, driving can be facilitated.

(ninth embodiment)

Next, a ninth embodiment of the present invention will be explained. The same or equivalent components as those in the first embodiment are denoted by the same reference numerals and redundant description thereof is omitted unless otherwise specified. Fig. 17 is a schematic cross-sectional view showing a vehicle including the vehicle headlamp according to the present embodiment. Fig. 18 is an enlarged view of the optical system unit 50 of the vehicle headlamp 1 shown in fig. 17. As shown in fig. 17 and 18, the configuration of the vehicle headlamp 1 according to the present embodiment is the same as the configuration of the vehicle headlamp 1 according to the first embodiment, but the light distribution pattern of the light emitted from the vehicle headlamp 1 according to the present embodiment is different from the light distribution pattern of the light emitted from the vehicle headlamp 1 according to the first embodiment.

The diffraction grating 54R of the present embodiment diffracts the laser light emitted from the collimator lens 53R so as to form a predetermined light distribution pattern. Specifically, the diffraction grating 54R diffracts the laser light incident from the collimator lens 53R so that the light emitted from each of the first, second, and third light-emitting optical systems 51R, 51G, and 51B becomes a light distribution pattern of low beams in a combining optical system 55 described below. The light distribution pattern also includes a luminous intensity distribution. Therefore, the diffraction grating 54R of the present embodiment has the same outer shape as the outer shape of the light distribution pattern of the low beam L and the light intensity of the light distribution pattern of the low beam L with the laser light emitted from the diffraction grating 54RThe distribution mode diffracts the laser light incident from the collimator lens 53R. In this way, the first light-emitting optical system 51R emits light of the red component of the light distribution pattern of the low beam L. In the present embodiment, the light of the red component emitted from the first light-emitting optical system 51R is defined as the first light L_R。

The diffraction grating 54G diffracts the laser light emitted from the collimator lens 53G so as to form a predetermined light distribution pattern, and the diffraction grating 54B diffracts the laser light emitted from the collimator lens 53B so as to form a predetermined light distribution pattern. Specifically, the diffraction gratings 54G and 54B diffract the laser beams incident from the collimator lenses 53G and 53B, respectively, so that the light beams emitted from the first light-emitting optical system 51R, the second light-emitting optical system 51G, and the third light-emitting optical system 51B in the combining optical system 55 form a light distribution pattern of the low beam L. As described above, the light distribution pattern also includes the light intensity distribution. Therefore, the diffraction gratings 54G and 54B of the present embodiment diffract the laser beams incident from the collimator lenses 53G and 53B, respectively, so that the laser beams emitted from the diffraction gratings 54G and 54B have the same outer shape as the outer shape of the light distribution pattern of the low beam L and have the light intensity distribution based on the light intensity distribution of the light distribution pattern of the low beam L. In this way, the second light-emitting optical system 51G emits light of the green component of the light distribution pattern of the low beam L, and the third light-emitting optical system 51B emits light of the blue component of the light distribution pattern of the low beam L. In the present embodiment, the green component light emitted from the second light-emitting optical system 51G is the second light L_GThe light of the blue component emitted from the third light-emitting optical system 51B is set as the third light L_B. Therefore, in the present embodiment, the first light L_RHas the longest wavelength of the second light L_GThe third light L_BSuccessively shorter.

The synthesizing optical system 55 has a first optical element 55f and a second optical element 55 s. The first optical element 55f is a light source that emits the first light L emitted from the first light-emitting optical system 51R_RAnd second light L emitted from the second light-emitting optical system 51G_GA resultant optical element. In the present embodiment, the first optical element 55f makes the first light L_RTransmits and reflects the second light L_GThereby synthesizing the first light L_RAnd the second light L_G. The second optical element 55s is the first light L to be combined by the first optical element 55f_RAnd the second light L_GAnd third light L emitted from the third light-emitting optical system 51B_BA resultant optical element. In the present embodiment, the second optical element 55s makes the first light L combined by the first optical element 55f_RAnd the second light L_Gtransmits and reflects the third light L_BThereby synthesizing the first light L_RAnd the second light L_GAnd the third light L_B. As such a first optical element 55f and a second optical element 55s, a wavelength selective filter in which an oxide film is laminated on a glass substrate can be cited. By controlling the type and thickness of the oxide film, light having a wavelength longer than a predetermined wavelength can be transmitted and light having a wavelength shorter than the predetermined wavelength can be reflected.

Thus, the first light L is emitted from the combining optical system 55_RThe second light L_GAnd the third light L_BThe resultant light.

Next, the emission of light by the vehicle headlamp 1 of the present embodiment will be described.

In the combining optical system 55, first, the first light L_RAnd the second light L_GFrom the first opticsThe elements 55f are combined and emitted. The first light L synthesized by the first optical element 55f_RAnd the second light L_Gthe second optical element 55s and the third light L_BAnd (4) synthesizing. At this time, the outer shapes of the respective lights are made the same as the outer shape of the low beam L, and therefore the outer shapes of the respective lights are combined with each other. That is, the positions of the light-emitting optical systems and the combining optical system are finely adjusted so that the first light L is emitted_RSecond light L_GAnd the third light L_BThe outer shapes of (a) and (b) are combined by the synthesizing optical system as described above. Thus, the first light L of red color_RGreen second light L_GAnd blue third light L_BThe combined light becomes white light. In addition, the first light L_RThe second light L_GAnd the third light L_BSince the luminous intensity distribution is based on the luminous intensity distribution of the light distribution pattern of the low beam L as described above, the white light after the light combination becomes the luminous intensity distribution of the low beam L.

The white light thus combined is emitted from the opening 59H of the cover 59, and the light is emitted from the vehicle headlamp 1 via the front cover 12. Since this light has a light distribution pattern of the low beam L, the irradiated light becomes the low beam L.

fig. 19 is a view showing a light distribution pattern for night illumination in the present embodiment, specifically, fig. 19(a) is a view showing a light distribution pattern for low beams, and fig. 19(B) is a view showing a light distribution pattern for high beams. In fig. 19, S denotes a horizontal line, and the light distribution pattern is indicated by a thick line. An area LA1 in the light distribution pattern of low beam L, which is the light distribution pattern for nighttime lighting shown in fig. 19(a), is an area having the highest luminous intensity, and the luminous intensities of the area LA2 and the area LA3 become lower in this order. That is, the diffraction gratings 54R, 54G, and 54B diffract the combined light so that the combined light forms a light distribution pattern including the light intensity distribution of the low beam L. As indicated by the broken line in fig. 19, light having a lower luminous intensity than the low beam L may be emitted from above the position where the vehicle headlamp 1 emits light to the low beam L. The light is an optical OHS for visual recognition of the mark. In this case, it is preferable that the diffracted light emitted from each of the diffraction gratings 54R, 54G, and 54B include the light OHS for visual confirmation of the marker. In this case, it can be understood that a light distribution pattern for night illumination is formed by the low beam L and the marker visual confirmation light OHS. The light distribution pattern for night illumination is used not only at night but also in dark places such as tunnels.

However, in the hologram element of the vehicle headlamp of patent document 1, white reference light is incident from a light source, and a light distribution pattern of low beams is formed by the diffracted light. However, white light is light obtained by combining light of a plurality of wavelengths. However, a hologram element, which is one of the diffraction gratings, has wavelength dependence. Therefore, light having different wavelengths included in white tends to have different light distribution patterns from each other by the hologram element. Therefore, when low beams are irradiated with the vehicle headlamp described in patent document 1, light leakage occurs in the vicinity of the edge of the light distribution pattern of the low beams, where light of different colors is exposed. Therefore, there is a demand for suppressing bleeding while reducing the size.

therefore, the vehicle headlamp 1 of the present embodiment includes three first, second, and third light-emitting optical systems 51R, 51G, and 51B including the light sources 52R, 52G, and 52B and the diffraction gratings 54R, 54G, and 54B, and a combining optical system 55 that combines the light emitted from the respective light-emitting optical systems. The light sources 52R, 52G, and 52B in the respective light emitting optical systems emit light of predetermined wavelengths different from each other, and the diffraction gratings 54R, 54G, and 54B in the respective light emitting optical systems diffract the light from the respective light sources 52R, 52G, and 52B so that the light combined by the combining optical system 55 becomes a light distribution pattern of the low beam L.

Therefore, the vehicle headlamp 1 of the present embodiment can form a light distribution pattern of the low beam L without using a shade, and thus can be downsized compared to a vehicle headlamp using a shade. In each of the light emitting optical systems, light of a predetermined wavelength emitted from the light sources 52R, 52G, and 52B is diffracted by the diffraction gratings 54R, 54G, and 54B, respectively, to form a light distribution pattern. At this time, in each light-emitting optical system, since the light diffracted by the diffraction gratings 54R, 54G, and 54B has a predetermined wavelength as described above, even if the diffraction gratings 54R, 54G, and 54B have wavelength dependency, it is possible to suppress occurrence of color bleeding in the vicinity of the edge of the light distribution pattern in the light emitted from the respective diffraction gratings 54R, 54G, and 54B. The light having the light distribution pattern in which the color bleeding is suppressed in this manner is synthesized by the synthesizing optical system 55 to form a light distribution pattern of the low beam L. Therefore, the low beam L emitted by the vehicle headlamp 1 of the present embodiment can be suppressed from bleeding near the edge of the light distribution pattern. In addition, in the present embodiment, since there are three light emitting optical systems that emit light of different wavelengths from each other, light of a desired color can be emitted by adjusting the luminous intensities of the light emitted from the respective light emitting optical systems.

In the vehicle headlamp 1 according to the present embodiment, the lights emitted from the first, second, and third light-emitting optical systems 51R, 51G, and 51B are combined by the combining optical system 55, and the combined light is emitted from the vehicle headlamp 1. Therefore, compared to the case where the lights emitted from the first, second, and third light-emitting optical systems 51R, 51G, and 51B are emitted from the vehicle headlamp 1 and combined outside the vehicle headlamp 1, it is possible to suppress the occurrence of color bleeding in the vicinity of the edge of the light distribution pattern to be irradiated regardless of the distance from the vehicle. Further, since the lights emitted from the respective light emitting optical systems are combined by the combining optical system 55 and then emitted from the vehicle headlamp, the light emitting portion of the vehicle headlamp 1 can be reduced, and the degree of freedom in design can be improved.

(tenth embodiment)

next, a tenth embodiment of the present invention will be described in detail with reference to fig. 20. The same or equivalent components as those in the ninth embodiment are denoted by the same reference numerals unless otherwise specified, and redundant description thereof is omitted.

Fig. 20 is a view showing an optical system unit of the vehicle headlamp of the present embodiment, similarly to fig. 18. As shown in fig. 20, an optical system unit 50 of a vehicle headlamp according to the present embodiment is different from the optical system unit 50 according to the ninth embodiment in that a combining optical system 55 is not provided, and lights emitted from a first light-emitting optical system 51R, a second light-emitting optical system 51G, and a third light-emitting optical system 51B are emitted from a cover 59 without being combined. In the present embodiment, the light emission direction of the first light emission optical system 51R, the second light emission optical system 51G, and the third light emission optical system 51B is set to the opening 59H side of the cover 59.

In the present embodiment, as in the ninth embodiment, light is diffracted so that the combined light forms a light distribution pattern of the low beam L in each of the diffraction grating 54R of the first light emission optical system 51R, the diffraction grating 54G of the second light emission optical system 51G, and the diffraction grating 54B of the third light emission optical system 51B. First light L emitted from diffraction grating 54R_RAnd second light L emitted from diffraction grating 54G_GAnd third light L emitted from diffraction grating 54B_BEach of the light beams is emitted from an opening 59H of the cover 59 and is irradiated to the outside of the vehicle headlamp via the front cover 12. At this time, the first light L_RA second light LG and a third light L_BThe light distribution patterns are irradiated so that the outer shapes of the light distribution patterns are substantially matched at a focal position separated from the vehicle by a predetermined distance. The focal position is set to a position 25m away from the vehicle, for example. That is, in the present embodiment, as described above, the light emission directions of the first light emission optical system 51R, the second light emission optical system 51G, and the third light emission optical system 51B are finely adjusted so that the outer shapes are uniform. In the present embodiment, as shown by the broken line in fig. 19, the optical OHS for visual confirmation of the marker may be emitted. In this case, as in the ninth embodiment, it is preferable that the diffracted light emitted from each of the diffraction gratings 54R, 54G, and 54B include the light OHS for visual confirmation of the marker.

According to the vehicle headlamp of the present embodiment, since the synthetic optical system 55 of the ninth embodiment is not used, a simple configuration can be provided. In addition, the first light L of the present embodiment_RSecond light L_GAnd the third light L_BThe outer shapes of (2) tend to be slightly deviated from each other except for the above-mentioned focal position. However, the deviation of the outer shape can be suppressed as compared with diffracted light obtained by incident white light on one diffraction grating. Therefore, according to the present embodiment, downsizing can be realizedAnd can inhibit the vehicle headlamp of the color bleed at the same time.

In the ninth and tenth embodiments, the low beam L is emitted from the vehicle headlamp 1, but the ninth and tenth embodiments are not limited to emitting light for night illumination. For example, the high beam H may be emitted from the vehicle headlamp 1. In this case, light of a light distribution pattern of high beam H, which is a light distribution pattern for night illumination shown in fig. 19(B), is irradiated. In the light distribution pattern of the high beam H in fig. 19(B), the region HA1 is the region having the highest luminous intensity, and the region HA2 is the region having a luminous intensity lower than the region HA 1. That is, each diffraction grating diffracts the light so that the combined light forms a light distribution pattern including the luminous intensity distribution of the high beam H.

In the ninth and tenth embodiments, the first light L emitting the red component is provided_REmits the second light L of the green component_GAnd third light L emitting a blue component_BThe third light-emitting optical system of (1). However, the number of the light emitting optical systems and the light emitted from the light sources are not limited as long as at least two of the light emitting optical systems have light sources that emit light of predetermined wavelengths different from each other and the combined light forms a light distribution pattern for night illumination. For example, in the case where two light emitting optical systems are provided, one light emitting optical system may emit green light and the other light emitting optical system may emit red light as yellow night light, or one light emitting optical system may emit blue light and the other light emitting optical system may emit yellow light as white night light.

The number of the light-emitting optical systems may be three or more. In this case, for example, a fourth light-emitting optical system may be provided that emits light of a yellow component near the light L. For example, the fourth light-emitting optical system may emit light of a yellow component near the light L, in addition to the red, green, and blue light-emitting optical systems described above. In addition, when the light intensities of a part of the red, green, and blue colors are low, the fourth light emission optical system may emit light of the same color component as the color with low light intensity.

In the ninth and tenth embodiments, a white balance adjustment circuit may be further provided. The white balance adjustment circuit can achieve a desired white balance by controlling the total luminous flux amount of light emitted from the light source 52R of the first light-emitting optical system 51R, the total luminous flux amount of light emitted from the light source 52G of the second light-emitting optical system 51G, and the total luminous flux amount of light emitted from the light source 52B of the third light-emitting optical system 51B. For example, the light source may be switched to emit warm white light or blue white light within the scope of the regulations.

In the ninth embodiment, the first optical element 55f makes the first light L_RTransmits and reflects the second light L_GThereby synthesizing the first light L_RAnd the second light L_GThe second optical element 55s makes the first light L synthesized by the first optical element 55f_RAnd the second light L_GTransmits and reflects the third light L_BThereby synthesizing the first light L_RThe second light L_GAnd the third light L_B. However, for example, the third beam LB and the second beam L may be combined in the first optical element 55f_GIn the second optical element 55s, the third light L synthesized by the first optical element 55f is emitted_BAnd the second light L_GIs combined with the first light LR. In this case, the positions of the first light emission optical system 51R and the third light emission optical system 51B of the ninth embodiment are replaced. In the ninth embodiment, a band-pass filter that transmits light in a predetermined wavelength band and reflects light in another wavelength band may be used for the first optical element 55f and the second optical element 55 s. The combining optical system 55 may be combined by combining the outer shapes of the lights emitted from the respective light emitting optical systems, and is not limited to the configuration of the ninth embodiment and the above configuration.

As described above, according to the present invention, it is possible to provide a vehicle lighting lamp which is easy to drive, a vehicle headlamp which is compact and can suppress color bleeding, and the present invention can be used in the field of vehicle lighting lamps such as automobiles.

Description of the reference numerals

1. vehicle headlamp

10. frame

20. lamp unit

30. radiator

40. cooling fan

51 R.first light-emitting optical system

51 G.second light-emitting optical system

51B. third light-emitting optical System

52R, 52G, 52B. light source

54R, 54G, 54B DEG diffraction grating

55. composite optical system

55 f. first optical element

55 s.second optical element

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Vehicle lighting lamp and vehicle headlamp

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