阅读说明：本技术 光照射装置 (Light irradiation device ) 是由 瓶子晃永 大岛律也 诹访胜重 于 2018-08-28 设计创作，主要内容包括：光照射装置(1)具有光源(11)、光学部件(20)和传感器(30)。光源(11)射出光(L0)。光学部件(20)被支承成以旋转轴(AR)为中心进行旋转,包含射出基于光(L0)的检测光(L4)的棱镜部(22)。传感器(30)接收检测光(L4),对检测光(L4)的光量进行检测。由传感器(20)接收的检测光(L4)的光量根据光学部件(20)旋转时的旋转方向(E)的位置而变化。(The light irradiation device (1) is provided with a light source (11), an optical member (20), and a sensor (30). The light source (11) emits light (L0). The optical member (20) is supported so as to rotate about a rotation Axis (AR) and includes a prism section (22) that emits detection light (L4) based on light (L0). The sensor (30) receives the detection light (L4) and detects the amount of light of the detection light (L4). The amount of light of the detection light (L4) received by the sensor (20) changes according to the position in the rotational direction (E) when the optical member (20) rotates.)

1. A light irradiation device is characterized by comprising:

a light source that emits light;

an optical member that is supported so as to rotate about a rotation axis and includes a 1 st prism portion that emits a 1 st detection light based on the light; and

a sensor that receives the 1 st detection light, detects a light amount of the 1 st detection light,

the light amount of the 1 st detection light received by the sensor changes according to the position of the rotation direction when the optical member rotates.

2. The light irradiation apparatus according to claim 1,

the 1 st prism portion is disposed on an outer peripheral portion of the optical member around the rotation axis.

3. A light irradiation apparatus according to claim 1 or 2,

the 1 st prism unit deflects the incident light and emits the deflected light as the 1 st detection light.

4. A light irradiation device as set forth in any one of claims 1 to 3,

the 1 st prism portion emits the 1 st detection light to a radial direction outer side of the optical member with the rotation axis as a center.

5. A light irradiation device as set forth in any one of claims 1 to 4,

the 1 st prism part includes a 1 st surface on which the light is incident and a 2 nd surface arranged to face the 1 st surface,

the 2 nd surface reflects the incident light to a radially outer side of the optical member with the rotation axis as a center.

6. A light irradiation device as set forth in any one of claims 1 to 5,

the optical member includes a light guide portion that guides the 1 st detection light to a light receiving portion of the sensor.

7. A light irradiation apparatus as set forth in claim 6,

the light guide portion includes a 1 st light emission end portion and a 2 nd light emission end portion arranged in parallel in a rotation direction of the optical member,

the 1 st detection light includes 2 nd detection light and 3 rd detection light,

the 1 st light emitting end emits the 2 nd detection light,

the 2 nd light emitting end emits the 3 rd detection light,

the sensor detects the light amount of the 1 st detection light based on the presence or absence of reception of the 1 st detection light and the reception of at least one of the 2 nd detection light and the 3 rd detection light.

8. A light irradiation apparatus as set forth in claim 7,

the light amount of the 2 nd detection light and the light amount of the 3 rd detection light are equal to each other.

9. A light irradiation apparatus as set forth in claim 7,

the light amount of the 2 nd detection light and the light amount of the 3 rd detection light are different from each other.

10. A light irradiation device as set forth in any one of claims 1 to 9,

the optical member includes a 2 nd prism portion that emits irradiation light based on the light,

the 2 nd prism unit changes the light distribution of the irradiation light according to a position in a rotation direction when the optical member rotates.

Technical Field

The present invention relates to a light irradiation device that emits light.

Background

For example, patent document 1 describes a light distribution control system that controls the light distribution of a headlight illumination device in accordance with the steering angle of the steering wheel of a vehicle. In this light distribution control system, the steering angle of the steering wheel is detected by a steering sensor as a detection unit. The steering sensor includes: a rotating plate that has a slit and rotates in conjunction with the steering of a steering wheel; and a plurality of photo-interrupters that detect a rotation direction and a rotation amount (rotation angle) of the rotating plate.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2003-81006 (for example, paragraphs 0010 to 0015, FIGS. 1 and 2)

Disclosure of Invention

Problems to be solved by the invention

However, each photointerrupter includes a light emitting element and a light receiving element. The light emitting element and the light receiving element are arranged to face each other with a rotating plate having a slit therebetween. Therefore, the light distribution control system has a problem that the structure of the detection unit is complicated.

The present invention has been made to solve the above problems of the prior art. The present invention aims to provide a light irradiation device capable of detecting the position of an optical component in the rotation direction by a simple structure.

Means for solving the problems

The light irradiation device of the present invention includes: a light source that emits light; an optical member that is supported so as to rotate about a rotation axis and includes a 1 st prism portion that emits a 1 st detection light based on the light; and a sensor that receives the 1 st detection light, and detects a light amount of the 1 st detection light, the light amount of the 1 st detection light received by the sensor changing according to a position in a rotation direction when the optical member rotates.

Effects of the invention

According to the present invention, the position of the optical member supported for rotation in the rotation direction can be detected with a simple configuration.

Drawings

Fig. 1 is a diagram schematically showing the configuration of a light irradiation device according to embodiment 1 of the present invention.

Fig. 2 (a), (B), and (C) are a front view, a side view, and a plan view schematically showing optical components of the light irradiation device according to embodiment 1.

Fig. 3 (a), (B), and (C) are diagrams illustrating a positional relationship between the light guide portion of the optical member of the light irradiation device and the photosensor in embodiment 1.

Fig. 4 is a diagram illustrating a relationship between a position of an optical member of the light irradiation device of embodiment 1 in a rotation direction and an amount of detected light received by the light sensor.

Fig. 5 (a) and (B) are a front view and a side view schematically showing optical components of a light irradiation device according to modification 1 of embodiment 1.

Fig. 6 is a front view schematically showing a light guide portion of the optical member shown in fig. 5 (a).

Fig. 7 (a) and (B) are diagrams showing a positional relationship between the light guide portion of the optical member shown in fig. 5 (a) and the optical sensor, and (C) and (D) are diagrams showing another positional relationship between the light guide portion of the optical member shown in fig. 5 (a) and the optical sensor.

Fig. 8 (a) and (B) are a front view and a side view schematically showing optical components of a light irradiation device according to modification 2 of embodiment 1.

Fig. 9 (a) is a front view schematically showing a light guide portion of the optical member shown in fig. 8 (a), and (B) is a plan view of a light emitting end portion of the light guide portion.

Fig. 10 (a) to (C) are diagrams showing a positional relationship between the light guide portion of the optical member shown in fig. 8 (a) and the optical sensor.

Fig. 11 is a view schematically showing the configuration of a light irradiation device according to embodiment 2 of the present invention.

Fig. 12 (a) and (B) are a front view and a side view schematically showing optical components of the light irradiation device of embodiment 2.

Fig. 13 is a view schematically showing the configuration of a light irradiation device according to embodiment 3 of the present invention.

Fig. 14 (a) and (B) are a front view and a side view schematically showing optical components of the light irradiation device of embodiment 3.

Detailed Description

A light irradiation device according to an embodiment of the present invention will be described below with reference to the drawings. The following embodiments are merely examples, and various modifications can be made within the scope of the present invention.

In order to easily understand the relationship between the drawings, coordinate axes of an xyz rectangular coordinate system are shown in each drawing as necessary.

The z-axis is a coordinate axis parallel to the rotation axis of the optical member. The z-axis is, for example, a coordinate axis parallel to the optical axis AP of the light source. Here, the light source is, for example, a light source 11 in fig. 1 described later. The + z-axis direction is, for example, a direction in which light is emitted from the light source 11.

The x-axis is a coordinate axis orthogonal to the z-axis. The x axis is, for example, a coordinate axis extending in a radial direction around the rotation axis of the optical member. The x-axis is, for example, parallel to the width direction of the light irradiation device.

The y-axis is a coordinate axis orthogonal to the z-axis and the x-axis. The y-axis is, for example, a coordinate axis extending in a radial direction around the rotation axis of the optical member. The y-axis is, for example, parallel to the height direction of the light irradiation device.

In the following embodiments, the optical member is rotated to change the distribution of emitted light.

A light irradiation device is known which irradiates light emitted from a light source forward through 2 wedge prisms. When each wedge prism is rotated around the rotation axis, the direction in which light emitted from the wedge prism is emitted is changed. The light emitted from the wedge prism is irradiated on the irradiation surface into a circular region.

For example, the illumination device can adopt the structure of such a light irradiation device. The illumination device scans a light beam having a large diameter and changes the irradiation direction. The lighting device is, for example, a spotlight that illuminates when the object moves. The light source of the lighting device is, for example, an LED or the like.

For example, the display device can adopt the structure of such a light irradiation device. The display device scans a laser beam having a relatively small diameter to form an image or display information.

For example, the projection apparatus can adopt the structure of such a light irradiation apparatus. The projection apparatus has an image display device on an optical path. The image display device corresponds to an image forming unit described later. The projection device projects an image or the like displayed by the image display device. The image display device is, for example, a liquid crystal panel or a light shielding plate having a shape such as a symbol. Thus, the projection device can move the projection image such as a symbol or an image. The projection device projects image information onto a road surface, a passageway, a wall, or the like. The projection device can also provide a notice or a guidance to the passer.

In addition, when the projection apparatus is applied to a vehicle, the projection apparatus can project an image on a road surface or the like. The projection device can also move the projected image on the road surface or the like. Thus, the projection device can provide information corresponding to the situation to, for example, a pedestrian. For example, the projection apparatus can guide the pedestrian to a position suitable for walking by projecting an arrow or the like onto the road surface.

For example, the vehicle lamp can employ such a structure of the light irradiation device. The vehicle lamp is, for example, a headlamp of a high beam of an automobile or the like. The high beam is a headlamp used in driving. The lamp distance of the high beam is, for example, 100 m. The headlight of the high beam illuminates a pedestrian ahead while traveling by moving an illuminated position in accordance with the pedestrian, for example.

As a vehicle lamp, the light irradiation device can be used as a low beam lamp of an automobile or the like. The low beam is a headlamp used when crossing an oncoming vehicle. The headlight distance of the low beam light is, for example, 30 m. The light irradiation device scans an irradiated position at a high speed, for example, to achieve light distribution required for a low beam lamp.

Further, as a vehicle lamp, the light irradiation device can be used as a light distribution variable headlamp system of an automobile or the like. The light distribution variable type headlamp system is, for example, ADB (Adaptive Driving Beam) or the like. The ADB only extinguishes the areas that make the vehicle in front feel dazzling so that the vehicle in front does not feel dazzling due to high beams while driving. In addition, the ADB uses a high beam to irradiate other areas, thereby ensuring the visibility and improving the safety.

However, when a mechanism for changing the direction of light irradiation is used for a long time, an error may occur in the position of the origin in the rotational direction of the rotating optical member. Therefore, a light irradiation device having a function of detecting the position of the optical member in the rotational direction is required. Further, there is a demand to avoid complication of the structure of the light irradiation device.

Therefore, in the following embodiments, the following light irradiation apparatus will be described: the position of the optical member that rotates about the rotation axis to change the distribution of emitted light in the rotation direction can be detected with a simple configuration.

In the following description, for ease of explanation, a stop position of the optical member is described as an origin position of the optical member as an example. However, the position at which the optical member is stopped is not limited to the origin position. The origin position is an example of a predetermined stop position of the optical member.

EXAMPLE 1

1-1 the structure of embodiment 1

Fig. 1 is a diagram schematically showing the configuration of a light irradiation device 1 according to embodiment 1 of the present invention. Fig. 2 (a), 2 (B), and 2 (C) are a front view, a side view, and a partial plan view schematically showing the optical member 20 of the light irradiation device 1 according to embodiment 1.

As shown in fig. 1, the light irradiation device 1 has a light source 11, an optical member 20, and a sensor 30. The light irradiation device 1 may include the light source control unit 11b, the lens unit 12, the heat sink 13, the lens barrel 14, the gear 31, the gear 32, the motor 33, the motor control unit 34, the lens barrel 35, the wedge prism 41, the lens barrel 44, or the image forming unit 90. The driving unit 37 includes, for example, a gear 31, a gear 32, a motor 33, and a motor control unit 34.

The light irradiation device 1 is a device suitable as a headlamp as a lighting device of a vehicle, for example. The light irradiation device 1 can be used as an illumination device other than a headlamp that changes a light distribution, for example. In addition, a structure for supporting the light irradiation device 1 is not shown in the figure.

1-1-1 light source 11

The light source 11 emits light L0. The optical axis AP is the optical axis of the light source 11. The optical axis AP of the light source 11 is, for example, an axis perpendicular to the light emitting surface 11a from the center of the light emitting surface 11a of the light source 11. Alternatively, the optical axis AP of the light source 11 is, for example, a main optical axis. The main optical axis is the optical center axis of the light radiated by the light source, and is generally the radiation direction of the highest luminosity.

The light source 11 shown in fig. 1 has a light emitting element. The Light Emitting element is, for example, an LED (Light Emitting Diode) or a laser. The Laser includes a semiconductor Laser (LD, Laser Diode: Laser Diode). The light source 11 can have a plurality of light emitting elements.

The light irradiation device 1 can have a drive circuit that drives the light source 11. The light source control unit 11b includes, for example, a drive circuit for driving the light source 11. The light source control unit 11b adjusts the light amount of the light source 11. The light amount adjustment includes turning on and off of the light source 11.

1-1-2 optical component 20

The optical member 20 is supported to rotate about a rotation axis AR. The rotation axis AR is, for example, parallel to the z-axis. The optical member 20 is provided in the lens barrel 35. The lens barrel 35 is supported to rotate with respect to the lens barrel 14, for example. The lens barrel is a cylindrical main body that supports a lens, a prism, or the like and blocks external light or the like.

Light L1 based on light L0 emitted from the light source 11 enters the optical member 20. When the lens unit 12 is not used, the light L1 is light L0. For example, the parallel light L1 is incident on the optical member 20. For example, light L1 parallel to the z-axis is incident on the optical member 20. For example, parallel light is incident on the optical member 20.

The optical member 20 deflects the incident light L1. The deflected light includes the irradiation light L2 and the detection light L4. The optical member 20 emits irradiation light L2. The optical member 20 emits the detection light L4. The optical axis AP and the rotation axis AR are, for example, the same axis.

The optical member 20 includes a prism portion 21 and a prism portion 22.

The prism portion 21 is a portion that changes the emission direction of the illumination light L2. When the optical member 20 rotates in the rotation direction E, the emission direction of the irradiation light L2 changes. The rotation direction E is a circumferential direction of the optical member 20 with the rotation axis AR as a center.

As shown in fig. 2 (a) and 2 (B), the prism portion 21 is, for example, a wedge prism. The prism portion 21 has a surface 21a and a surface 21 b. The surface 21a and the surface 21b are disposed opposite to each other.

The surface 21a is formed on the light incident surface side of the optical member 20. The surface 21a is formed on the light incident surface of the optical member 20, for example. The surface 21a is formed on the light source 11 side of the optical member 20. The surface 21a is, for example, a plane. The plane 21a has an intersection with the rotation axis AR.

The surface 21b is formed on the light exit surface side of the optical member 20. The surface 21b is formed on the light exit surface of the optical member 20, for example. The surface 21b is, for example, a flat surface. The plane 21b has an intersection with the rotation axis AR.

The wedge prism is a prism in which a light exit surface is inclined with respect to a light entrance surface. The wedge prism includes an inclined optical surface. The 1 face of the wedge prism is inclined at a small angle with respect to the other face. The inclination angle of 1 facet of the wedge prism with respect to the other facet is called a wedge angle or a vertex angle.

The light incident to the wedge prism is refracted at an angle corresponding to the inclination angle of the wedge prism and exits. Light incident on the wedge prism is refracted in a direction in which the thickness of the prism is thick. Light incident on the wedge prism is deflected in a direction in which the thickness of the prism is thick. The angle of light exiting the wedge prism relative to light incident on the wedge prism is referred to as the off-angle.

In the following embodiments, 1 surface of the wedge prism is a surface perpendicular to the rotation axis. However, the 2 surfaces of the wedge prism may be inclined with respect to the rotation axis. That is, the light incident surface and the light emitting surface of the wedge prism may be inclined with respect to the rotation axis.

The face 21a and the face 21b are inclined faces to each other. The face 21a is inclined with respect to the face 21 b. The surface 21a is inclined with respect to the rotation axis AR. In fig. 1 and 2 (B), the surface 21a is parallel to the x axis and inclined to the y axis. The surface 21b is, for example, a surface perpendicular to the rotation axis AR. The surface 21b is parallel to both the x-axis and the y-axis. Regarding the thickness of the prism portion 21, the-y-axis side is thicker than the + y-axis side. Therefore, the light incident on the prism portion 21 is deflected toward the-y axis.

Light L1 enters surface 21 a. The light L1 incident on the surface 21a is, for example, parallel to the z-axis. The light L1 incident on the surface 21a is, for example, parallel to the rotation axis AR. Light L1 is refracted at surface 21 a. The light L1 refracted at the surface 21a is refracted at the surface 21 b. The light L1 refracted at the surface 21b is emitted from the surface 21b as the irradiation light L2. The irradiation light L2 is light inclined with respect to the rotation axis AR. The irradiation light L2 is light inclined with respect to the z-axis.

The traveling direction of the irradiation light L2 changes depending on the position of the optical component 20 in the rotation direction E. That is, the light distribution of the irradiation light L2 changes depending on the position of the optical member 20 in the rotation direction E.

However, the surface 21a may be a surface perpendicular to the rotation axis AR, and the surface 21b may be a surface inclined with respect to the rotation axis AR. That is, the surface 21a may be a surface parallel to both the x axis and the y axis, and the surface 21b may be a surface parallel to the x axis and inclined to the y axis. In this case, light L1 parallel to the z-axis enters surface 21a perpendicularly. Light L1 parallel to the rotation axis AR is incident perpendicularly to the surface 21 a. The light L1 enters the surface 21a and is refracted at the surface 21 b. The light L1 refracted at the surface 21b is emitted from the surface 21b as the irradiation light L2. The irradiation light L2 is light inclined with respect to the rotation axis AR. The irradiation light L2 is light inclined with respect to the z-axis.

The prism section 22 extracts the detection light L4 from the light L1 incident on the optical member 20. The prism unit 22 is a prism for detecting light.

The prism section 22 is formed on the outer peripheral side of the optical component 20 with the rotation axis AR as the center. The prism portion 22 is formed on the outer peripheral portion of the optical member 20 around the rotation axis AR. The prism portion 22 is formed, for example, in a portion of the prism portion 21 having a small thickness. The prism portion 22 is formed, for example, in a portion having a thickness smaller than the average wall thickness of the prism portion 21. The prism portion 22 is formed at a portion where the thickness of the prism portion 21 is the thinnest, for example.

As shown in fig. 2 (a) and 2 (B), the prism portion 22 has a surface 22a and a surface 22B. The surface 22a and the surface 22b are disposed opposite to each other.

The surface 22a is formed on the light incident surface side of the optical member 20. The surface 22a is formed on the light incident surface of the optical member 20, for example. The surface 22a is formed on the light source 11 side of the optical member 20. The face 22a is, for example, a plane.

The surface 22b is formed on the light exit surface side of the optical member 20. The surface 22b is formed on the light exit surface of the optical member 20, for example. The surface 22b is, for example, the same surface as the surface 21 b. As shown in fig. 2 (B), the surface 22B is flush with the surface 21B. The face 22b is, for example, a plane.

The face 22a and the face 22b are inclined faces to each other. Face 22a is inclined relative to face 22 b. The face 22a is inclined with respect to the rotation axis AR. In fig. 1 and 2 (B), the surface 22a is parallel to the x axis and inclined to the y axis. As shown in fig. 2 (B), the surface 22a is inclined in the opposite direction to the surface 21 a. The surface 22b is, for example, a surface perpendicular to the rotation axis AR. The surface 22b is parallel to both the x-axis and the y-axis.

In the direction of the rotation axis AR, the outer peripheral side of the surface 22a centered on the rotation axis AR is positioned closer to the light source 11 than the inner peripheral side. In the direction of the rotation axis AR, the outer peripheral side of the surface 22a centered on the rotation axis AR protrudes further toward the direction in which the light L1 enters than the inner peripheral side. The direction side in which the light L1 is incident is the-z-axis direction side. That is, in the direction of the rotation axis AR, the outer peripheral side of the surface 22a centered on the rotation axis AR protrudes more upstream (toward the (-z-axis direction) side) in the traveling direction of the light L1 than the inner peripheral side. The outer peripheral side of the surface 22a around the rotation axis AR protrudes in the direction opposite to the direction (+ z-axis direction) in which the light L1 enters (i.e., the (-z-axis direction) than the inner peripheral side.

As shown in fig. 1, the light L1 is, for example, light parallel to the z-axis. The light L1 is, for example, light parallel to the rotation axis AR. Light L1 is incident on surface 22 a. Light L1 is refracted at surface 22 a. The light L1 is refracted at the surface 22a of the prism portion 22. The light L1 is refracted toward the outer peripheral side of the optical component 20 around the rotation axis AR.

Light L1 refracted at surface 22a is reflected at surface 22 b. The light L1 refracted at the surface 22a is totally reflected at the surface 22b, for example. The light L1 refracted at the surface 22a is reflected toward the outer peripheral side of the optical component 20 around the rotation axis AR. The light L1 reflected by the surface 22b travels toward the outer periphery of the optical component 20. Light L1 is reflected by surface 22b and travels toward light guide unit 23.

Light L1 reflected on surface 22b enters light guide 23 as detection light L4. Light L1 exits through light guide 23. The light L1 is emitted as detection light L4. The light L1 passes through the light guide portion 23 and is emitted from the light emitting end portion 24 and the light emitting end portion 25 as detection light L4.

However, the prism portion 22 may have a surface 22a parallel to both the x-axis and the y-axis and a surface 22b parallel to the x-axis and inclined to the y-axis. In this case, incident light L1 parallel to the z-axis enters from the surface 22 a. Then, the light L1 is reflected by the surface 22b and travels toward the light guide unit 23. Light L1 exits through light guide 23. The light L1 is emitted as detection light L4. The light L1 passes through the light guide portion 23 and is emitted from the light emitting end portion 24 and the light emitting end portion 25 as detection light L4.

Further, by reducing the area of the prism portion 22, the adverse effect on the light distribution of the illumination light L3 can be reduced. Further, by limiting the area of the prism portion 22 to the outer peripheral side of the optical member 20 around the rotation axis AR, it is possible to reduce the adverse effect on the light distribution of the illuminating light L3. Here, the adverse effect is, for example, a partial loss of the light distribution of the irradiation light L2.

The prism portion 21, the prism portion 22, and the light guide portion 23 are integrally formed, for example. The material of prism portion 21, prism portion 22, and light guide portion 23 is a transparent material. The transparent material is, for example, glass or plastic. The prism portion 21, the prism portion 22, and the light guide portion 23 are made of a material that transmits light, for example.

The light guide unit 23 guides the detection light L4 deflected by the prism unit 22. The light guide unit 23 receives the detection light L4 emitted from the prism unit 22. The light guide unit 23 guides the detection light L4 emitted from the prism unit 22. The light guide portion 23 is provided radially outward of the prism portion 22 about the rotation axis AR. The light guide unit 23 guides the detection light L4 deflected outward in the radial direction around the rotation axis AR by the prism unit 22. "light guiding" refers to guiding light for propagation.

The light guide portion 23 has a rod shape, for example. The cross section of light guide unit 23 is, for example, circular or rectangular. The detection light L4 entering the light guide unit 23 is reflected by the side surface of the light guide unit 23. The detection light L4 entering the light guide unit 23 is reflected by the side surface of the light guide unit 23 and guided. The reflection at the side of the light guide part 23 is, for example, total reflection. Light guide portion 23 is disposed, for example, through opening 36.

As shown in fig. 2 (a) to 2 (C), the light guide portion 23 can have a light emitting end portion 24 and a light emitting end portion 25. The light emitting end 24 and the light emitting end 25 are arranged in parallel in the rotation direction E of the optical member 20. The light emitting end 24 and the light emitting end 25 are arranged in parallel in the circumferential direction of the optical member 20. The light emitting end 24 and the light emitting end 25 are arranged in parallel in the circumferential direction of the optical member 20 about the rotation axis AR. The light emitting end 24 and the light emitting end 25 face radially outward of the optical member 20 about the rotation axis AR. The light guide unit 23 may have one light emitting end.

The detection light L4 deflected by the prism unit 22 travels inside the light guide unit 23. The detection light L4 that has traveled inside the light guide unit 23 is split into the light emitting end 24 and the light emitting end 25. The detection light L4 entering the light guide unit 23 enters the light emitting end portions 24 and 25 from the light incident portions 24b and 25 b. The detection light L4 incident on the light emitting ends 24 and 25 travels inside the light emitting ends 24 and 25. The detection light L4 that has traveled inside the light emitting ends 24 and 25 is emitted from the light emitting surfaces 24a and 25 a. The detection light L4 includes a detection light L41 and a detection light L42. The divided detection light L4 is emitted from the light emitting end 24 as detection light L41. The detection light L41 is emitted from the light emitting end 24. The divided detection light L4 is emitted from the light emitting end 25 as detection light L42. The detection light L42 is emitted from the light emitting end 25.

As shown in fig. 2 (a) and 2 (C), a gap is formed between the light emitting end 24 and the light emitting end 25. The gap is formed by a notch or the like, for example. The gap is, for example, a cut-out portion. In the example of fig. 2 (a) to 2 (C), a V-groove-shaped notch is formed between the light emitting end 24 and the light emitting end 25.

In the example of fig. 2 (a) to 2 (C), the light guide unit 23 is formed such that the light amount of the detection light L41 emitted from the light emitting end portion 24 and the light amount of the detection light L42 emitted from the light emitting end portion 25 are equal to each other. That is, the light amount of the detection light L41 and the light amount of the detection light L42 are equal.

In the circumferential direction of the optical member 20, the length W1 is defined as the dimension from the end outside the light exit surface 24a of the light exit end portion 24 to the end outside the light exit surface 25a of the light exit end portion 25. The dimension in the z-axis direction of the light emitting surfaces 24a and 25a of the light emitting ends 24 and 25 is defined as a width D1. The dimension of the light exit surfaces 24a and 25a in the z-axis direction is the dimension of the optical member 20 in the thickness direction.

In the example of fig. 2 (a) to 2 (C), the length W1 and the width D1 of the light emitting end of the light guide unit 23 are equal to the length and the width of the light receiving unit 30b of the sensor 30. The length W1 and the width D1 of the light emitting end of the light guide 23 may be smaller than the size of the light receiving unit 30b of the sensor 30. That is, the length W1 and the width D1 of the light exit end of the light guide unit 23 may be formed so as to be within the light receiving region of the sensor 30.

For example, when the detection light L4 is guided to the sensor 30 using an optical fiber or the like, the light receiving unit 30b of the sensor 30 becomes a portion of the optical fiber or the like on which the detection light L4 enters.

The optical member 20 may have a light guide portion 23. However, the optical member 20 may not include the light guide portion 23. Examples of the optical member without the light guide portion 23 will be described later in embodiment 2 (fig. 11) and embodiment 3 (fig. 13).

As shown in fig. 1, light guide unit 23 is disposed to penetrate through opening 36. The opening 36 is formed in the side surface of the lens barrel 35.

1-1-3 sensor 30

The sensor 30 receives the detection light L4. The sensor 30 detects the amount of light of the detection light L4. The detection of the light amount of the detection light L4 includes the detection of the presence or absence of the reception of the detection light L4 by the sensor 30. The detection of the light amount of the detection light L4 includes the detection of a change in the light receiving amount of the detection light L4 by the sensor 30.

The sensor 30 receives the detection light L4 deflected by the prism portion 22. The amount of light received by the detection light L4 from the sensor 30 varies depending on the position of the optical member 20 in the rotation direction E. The amount of light received by the sensor 30 varies depending on the position of the optical member 20 in the rotation direction E. The amount of the detection light L4 received by the sensor 30 changes according to the position of the light guide portion 23 in the rotation direction E.

The sensor 30 receives the deflected detection light L4, thereby detecting the position of the optical component 20 in the rotation direction E. The sensor 30 can detect, for example, the origin position in the rotation direction E of the optical member 20. The origin position is determined based on the amount of light received by the sensor 30, for example.

The sensor 30 is for example a light sensor. The sensor 30 is, for example, a photodiode or a phototransistor. The sensor 30 converts the light into an electrical signal. Generally, the sensor 30 has an electrical performance capable of detecting an illuminance in a range of about 0.1 lux to 1000 lux.

Lens unit 12 of 1-1-4

The lens section 12 converts the light L0 into light L1. The light L0 is emitted from the light source 11. The light L0 travels in the + z-axis direction. The light L1 travels in the + z-axis direction. The light L1 is incident light to the optical component 20.

The lens unit 12 condenses light, for example. The lens unit 12 is, for example, a converging lens. The divergence angle of the light L1 emitted from the lens portion 12 is smaller than the divergence angle of the light L0 incident on the lens portion 12. The light L1 is, for example, parallel light. "converging" means concentrating light in one place or direction.

In the case of projecting an image using the image forming unit 90 or the like, the lens unit 12 is a projection lens. Here, the image includes a light distribution pattern. The focal point of the lens unit 12 is located on the image plane formed by the image forming unit 90, for example.

The lens section 12 is a 1-lens or a lens group. The lens group has a plurality of lenses.

The optical axis AC is the optical axis of the lens unit 12. The optical axis AC and the rotation axis AR are, for example, the same axis. The optical axis AC and the optical axis AP are, for example, the same axis.

1-1-5 drive section 37

The driving section 37 has a motor 33, a motor control section 34, a gear 32, and a gear 31. The driving unit 37 rotates the optical member 20.

The motor 33 is, for example, a stepping motor or a DC (direct current) motor. A gear 32, for example, is attached to a shaft of the motor 33. When the shaft of the motor 33 rotates, the gear 32 rotates. The motor 33 rotates the gear 32.

The motor control unit 34 controls the rotation, stop, rotation direction, rotation speed, and the like of the motor 33. The motor control unit 34 has a circuit for driving the motor 33, for example.

The gear 32 transmits the rotational force of the motor 33 to the gear 31. The gear 32 is attached to a shaft of a motor 33, for example. The gear 32 meshes with the gear 31.

The gear 31 is provided to the lens barrel 35, for example. The gear 31 is provided on the outer periphery of the lens barrel 35. Gear 31 is provided on the outer periphery of barrel 35. The lens barrel 35 is rotated by the rotational force transmitted from the gear 32 to the gear 31. By the rotation of the lens barrel 35, the optical member 20 rotates. For example, the gear 31 may be provided on the outer periphery of the optical member 20. The optical member 20 is rotated by the rotational force transmitted from the gear 32 to the gear 31.

Wedge prism 41

As shown in fig. 1, the light irradiation device 1 may also have a wedge prism 41. The wedge prism 41 enters the irradiation light L2. The wedge prism 41 is an optical component that enters the irradiation light L2. The irradiation light L2 is light emitted from the optical component 20.

The wedge prism 41 has a light incident surface 42 and a light exit surface 43. The light incident surface 42 and the light exit surface 43 are disposed to face each other. The light incident surface 42 is formed on the optical member 20 side. The light incident surface 42 is, for example, a flat surface. The light exit surface 43 is, for example, a flat surface.

The light incident surface 42 and the light exit surface 43 are surfaces inclined to each other. The light incident surface 42 is, for example, perpendicular to the optical axis AP. The light incident surface 42 is parallel to both the x axis and the y axis. The light exit surface 43 is inclined with respect to the light entrance surface 42. The light exit surface 43 is inclined with respect to the optical axis AP, for example. In fig. 1, the light exit surface 43 is parallel to the x axis and inclined to the y axis. The optical axis AP is the optical axis of the light source 11. With respect to the thickness of the wedge prism 41, the + y-axis side is thicker than the-y-axis side. Therefore, the light incident on the wedge prism 41 is deflected toward the + y-axis side.

The irradiation light L2 is refracted at the light incidence surface 42. The irradiation light L2 refracted at the light incident surface 42 is refracted at the light exit surface 43. The irradiation light L2 refracted at the light exit surface 43 is emitted from the light exit surface 43 as irradiation light L3. The irradiation light L3 is light inclined with respect to the z-axis. The irradiation light L3 is, for example, light inclined with respect to the optical axis AP. The irradiation light L3 is, for example, light inclined with respect to the optical axis AC. The irradiation light L3 is, for example, light inclined with respect to the rotation axis AR.

The wedge prism 41 changes the traveling direction of the irradiation light L2 and emits the irradiation light L3. That is, the traveling direction of the irradiation light L3 is determined by the positional relationship between the prism portion 21 of the optical member 20 and the wedge prism 41. The traveling direction of the irradiation light L3 is determined by the deflection direction of the prism portion 21 of the optical component 20 and the deflection direction of the wedge prism 41. The light distribution of illumination light L3 includes the traveling direction of illumination light L3.

The light incident surface 42 may be a surface parallel to both the x axis and the y axis, and the light emitting surface 43 may be a surface parallel to the x axis and inclined to the y axis. That is, the light incident surface 42 of the wedge prism 41 may be inclined with respect to the optical axis AP, and the light exit surface 43 may be perpendicular to the optical axis AP.

The wedge prism 41 can rotate similarly to the optical member 20. The rotation axis AR and the rotation axis of the wedge prism 41 are, for example, the same axis. The rotation axis of the wedge prism 41 and the optical axis AP are, for example, the same axis. The rotation axis of the wedge prism 41 and the optical axis AC are, for example, the same axis.

The shape, number, and position of the other optical members for changing the light distribution of the illuminating light L2 are not limited to the illustrated example of the wedge prism 41.

1-1-7 radiator 13 and lens barrel 14, 35, 44

The heat sink 13 holds the light source 11, for example. The heat sink 13 radiates heat generated by the light source 11 to the outside.

The lens barrel 14 is a non-rotating lens barrel. The lens barrel 14 is attached to the heat sink 13, for example. The lens barrel 14 holds the lens unit 12, for example.

The lens barrel 35 holds the optical member 20. The lens barrel 35 rotates about a rotation axis AR. The lens barrel 35 is held so as to rotate about the rotation axis AR. The lens barrel 35 is supported, for example, to rotate with respect to the lens barrel 14. The lens barrel 35 is supported, for example, to rotate with respect to the lens barrel 44. The lens barrel 35 is supported, for example, to rotate relative to the light source 11.

By the rotation of the lens barrel 35, the optical member 20 rotates. The optical member 20 rotates about the rotation axis AR.

The lens barrel 35 has an opening 36. The lens barrel 35 has an opening 36 on a side surface.

The opening 36 may be formed of a transparent member. The light-transmitting member is a material that transmits light. In this case, light guide unit 23 is disposed without penetrating opening 36. The light emitting ends 24 and 25 of the light guide portion 23 are disposed to face the inner surface of the opening 36. The light emitting surfaces 24a and 25a of the light emitting ends 24 and 25 are disposed to face the inner surface of the opening 36.

The lens barrel 44 holds the wedge prism 41. The lens barrel 44 is held by the lens barrel 14, for example. The lens barrel 44 is fixed to the lens barrel 14, for example. The lens barrel 44 is held by the heat sink 13, for example. The lens barrel 44 is fixed to the heat sink 13, for example.

The lens barrel 44 is, for example, a non-rotating lens barrel. However, the lens barrel 44 may be a rotating lens barrel. In this case, the lens barrel 44 may be held by the lens barrel 35, for example.

The lens barrel 44 has an opening 45. The lens barrel 44 has an opening 45 at a side surface.

The position of the opening 45 in the z-axis direction is the same as the position of the opening 36 in the z-axis direction. The position of the opening 45 in the rotation axis AR direction is the same as the position of the opening 36 in the rotation axis AR direction. The lens barrel 35 is rotated with respect to the lens barrel 44. The circumferential position of the opening 45 is matched with the circumferential position of the opening 36. The opening 45 is located opposite to the opening 36. The position of the opening 45 relative to the opening 36 is, for example, the origin position.

At this time, the detection light L4 emitted from the light guide 23 passes through the opening 45 and reaches the sensor 30. That is, the detection light L4 emitted from the light emitting end portion 24 and the light emitting end portion 25 passes through the opening 45 and enters the light receiving portion 30b of the sensor 30. Here, the detection light L4 is light deflected by the prism unit 22 and emitted from the light guide unit 23.

The opening 45 may be formed of a light-transmitting member. In this case, the light emitting ends 24 and 25 of the light guide unit 23 are disposed to face the inner surface of the opening 45. The light emitting surfaces 24a and 25a of the light emitting ends 24 and 25 are disposed to face the inner surface of the opening 45. In this case, the detection light L4 emitted from the light guide unit 23 passes through the opening 36 and the opening 45 and reaches the sensor 30. That is, the detection light L4 emitted from the light emitting end portion 24 and the light emitting end portion 25 passes through the opening 36 and the opening 45 and enters the light receiving portion 30b of the sensor 30. The detection light L4 deflected by the prism portion 22 passes through the opening 36 and enters the light receiving portion 30b of the sensor 30. The detection light L4 deflected by the prism portion 22 passes through the opening 45 and enters the light receiving portion 30b of the sensor 30.

1-1-8 image forming section 90

The light irradiation device 1 may be a projection device for projecting an image. In this case, the lens unit 12 projects an image. The lens unit 12 can enlarge the projected image, for example. That is, the lens unit 12 is a projection lens.

The projected image is, for example, an image formed on the light emitting surface 11a of the light source 11. The image formed on the light-emitting surface 11a of the light source 11 includes an image obtained by changing the shape and luminance distribution of the light-emitting surface. The projected image is, for example, a light distribution pattern formed by light emitted from the light source 11. The light distribution pattern includes a pattern obtained by changing the light distribution of the light emitted from the light source 11.

The image forming unit 90 forms a projected image. For example, the lens unit 12 projects an image formed by the image forming unit 90. The image forming unit 90 is disposed between the light source 11 and the lens unit 12. The image forming unit 90 is disposed at a focal position of the lens unit 12, for example. The lens unit 12 projects an image formed by the image forming unit 90. Such as the shape of an object that reflects the eyes. Such as, for example, an image. The image is an image generated by refraction or reflection of light. The video includes a moving image and a still image. The image includes a light distribution pattern.

The image forming unit 90 is, for example, a light shielding plate. The light shielding plate is provided with a hole having a shape such as an arrow. The shape of an arrow formed by the light shielding plate is projected by the lens portion 12.

The image forming unit 90 is, for example, a liquid crystal panel. In this case, a moving image or the like formed by the image forming unit 90 is projected by the lens unit 12.

1-2 operation of embodiment 1

1-2-1 origin position detection operation

Fig. 3 (a) to 3 (C) are views showing the positional relationship between the light guide portion 23 of the optical member 20 and the sensor 30 in the light irradiation device 1 according to embodiment 1. Fig. 3 (a) to 3 (C) show positions P1, P2, and P3 when the optical component 20 rotates about the rotation axis AR. The positions P1, P2, and P3 are positions of the light emitting end 24 and the light emitting end 25 in the rotational direction E with respect to the sensor 30. The rotation direction E is a rotation direction of the optical member 20 about the rotation axis AR.

Fig. 3 (a) shows a position P1 in the rotation direction E. Fig. 3 (B) shows a position P2 in the rotation direction E. Fig. 3 (C) shows a position P3 in the rotation direction E.

Fig. 4 is a diagram showing the relationship of the positions P1, P2, P3 and the amount of light of the detection light L4 received by the sensor 30. Fig. 4 is a graph showing the light receiving amount of the sensor 30 at the positions P1, P2, P3. The detection light L4 includes a detection light L41 and a detection light L42. The light receiving amount of the sensor 30 shown in fig. 4 is the light receiving amount of the light emitted from the light guide unit 23.

At the position P1, neither the light exit end 24 nor the light exit end 25 faces the sensor 30. Therefore, neither the detection light L41 emitted from the light emitting end portion 24 nor the detection light L42 emitted from the light emitting end portion 25 reaches the sensor 30. At this time, the level of the signal indicating the amount of light received by the sensor 30 is zero.

At the position P2, the light emitting end 24 faces the sensor 30, and the light emitting end 25 does not face the sensor 30. Therefore, the detection light L41 emitted from the light emitting end 24 reaches the sensor 30. However, the detection light L42 emitted from the light emitting end 25 does not reach the sensor 30. At this time, the level of the signal indicating the amount of light received by the sensor 30 is R. R is the level of a signal indicating the amount of the detection light L41 emitted from the light emitting end 24.

In fig. 3a to 3C, the light amount of the detection light L41 emitted from the light emitting end portion 24 is equal to the light amount of the detection light L42 emitted from the light emitting end portion 25. Therefore, when the optical member 20 rotates in the reverse direction, the level of the signal indicating the amount of light received by the sensor 30 is also R in the state corresponding to the position P2. Here, the "state corresponding to the position P2" refers to a state in which the light emitting end 25 faces the sensor 30 and the light emitting end 24 does not face the sensor 30.

At the position P3, both the light emitting end 24 and the light emitting end 25 face the sensor 30. Therefore, both the detection light L41 emitted from the light emitting end portion 24 and the detection light L42 emitted from the light emitting end portion 25 reach the sensor 30. At this time, the level of the signal indicating the amount of light received by the sensor 30 is 2R. 2R is 2 times of R.

For example, the origin position of the optical component 20 is assumed to be a case where the level of the signal indicating the amount of light received by the sensor 30 is 2R. The light irradiation device 1 can obtain R at the signal level before obtaining 2R at the signal level of the origin position. Therefore, for example, even when the optical component 20 is rotated at a high speed, the rotation speed of the optical component 20 can be reduced and the optical component 20 can be stopped after R is obtained at the signal level. For example, the operation of detecting the origin position and stopping the optical component 20 is an example of the positioning operation of the optical component 20.

1-2-2 light quantity control when detecting origin position

In the light irradiation device 1, the light L1 incident on the prism portion 22 is guided to the sensor 30. The light L1 incident on the prism portion 22 is, for example, a light incident on the peripheral portion of the optical member 20. The peripheral portion of the optical member 20 is located around the optical member 20 centered on the rotation axis AR. By actively guiding the light L1 incident on the optical member 20 to the sensor 30 in this way, for example, even when the luminance of the light source 11 is reduced, the position of the optical member 20 in the rotation direction E is easily detected. That is, it is easy to reduce the light amount of the light source 11 and detect the position of the optical member 20 in the rotation direction E. For example, the amount of light received by the sensor 30 can be increased as compared with a method of guiding stray light in the lens barrel 35 to the sensor 30. Stray light in the lens barrel 35 leaks out of the lens barrel 35 from the opening 36. The stray light leaking to the outside of the lens barrel 35 is received by the sensor 30.

The light irradiation device 1 can reduce the amount of light when the optical member 20 is returned to the original position, compared to the amount of light when the irradiation target object is irradiated with light. For example, when the optical member 20 is returned to the original position by the amount of light when the irradiation target object is irradiated with light, the irradiation light L3 performs an unexpected movement on the irradiation surface. The unpredictable movement of the irradiation light L3 may cause an accident or the like to occur. For example, the light irradiation device 1 guides a passer by an error. For example, the light irradiation device 1 dazzles the front vehicle.

The light irradiation device 1 can return the optical member 20 to the original position with a small amount of light. This allows the light irradiation device 1 to reduce the amount of irradiation light L3 when the optical component 20 is returned to the origin position. The light irradiation device 1 reduces the amount of light L0 emitted from the light source 11 during the positioning operation of the optical member 20. The light irradiation device 1 reduces the light amount of the irradiation light L3 during the positioning operation of the optical member 20. Further, the light irradiation device 1 can reduce the influence of the unexpected movement of the irradiation light L3 on the irradiation surface. Here, the positioning of the optical member 20 is the positioning of the optical member 20 with respect to a position as a reference of the rotational operation.

< 1-3 > effects of embodiment 1

The light irradiation device 1 can detect the position of the optical member 20 in the rotation direction E using the light L0 emitted from the light source 11. Therefore, the light irradiation device 1 does not require a light emitting element for detecting the position of the optical member 20 in the rotation direction E. In this way, the light irradiation device 1 can detect the position of the optical member 20 in the rotation direction E with a simple configuration. The position of the optical member 20 in the rotation direction E is, for example, a stop position of the optical member 20. The position of the optical member 20 in the rotation direction E is a stop position of the optical member 20 with respect to a position as a reference.

The light irradiation device 1 can rotate the optical member 20 at a high speed until the level of the signal output from the sensor 30 becomes R. Thereby, the light irradiation device 1 can shorten the detection time of the origin position of the optical member 20 in the rotation direction E.

In step 3, the light irradiation device 1 rotates the optical member 20 at a low speed after the level of the signal output from the sensor 30 becomes R. Thereby, the light irradiation device 1 can improve the accuracy of the stop position of the optical member 20 in the rotation direction E. That is, the light irradiation device 1 can improve the accuracy of the origin position of the optical member 20. The origin position is a position as a reference.

For example, when the motor 33 is a stepping motor, high-speed rotation until the signal level becomes R is performed in a through region of the stepping motor. Then, the low-speed rotation after the signal level becomes R is performed in the self-start region of the stepping motor.

The through region is a region in which synchronous operation is possible when the stepping motor is driven at a high speed. When the stepping motor is driven in the through region, a slow-up/slow-down control is used in which the stepping motor is started at once in the self-start region and the pulse speed is gradually increased. The self-start region is a region in which start, forward rotation, or reverse rotation can be controlled in synchronization with a pulse signal input from the outside.

In the light irradiation device 1, the prism portion 22 is provided on the light incident surface side of the optical member 20. That is, it is not necessary to provide a protrusion on the light exit surface side of the optical member 20. Therefore, the gap between the optical member 20 and the wedge prism 41 can be reduced. This can reduce unnecessary light. Further, the utilization efficiency of the light emitted as the irradiation light L3 can be improved. Here, the unnecessary light is light emitted from the optical member 20 without being incident on the wedge prism 41.

In the light irradiation device 1, the optical member 20 having the light guide portion 23 is used. This can reduce the emission area of the detection light L4 emitted from the prism unit 22. Here, the emission region of the detection light L4 is the light emission surface of the light guide unit 23. In embodiment 1, the light emitting surfaces 24a and 25a of the light emitting end portions 24 and 25 are shown as an example. However, the light emitting end portion may not be divided. That is, the light emitting end may be one.

Therefore, the sizes of the openings 36 and 45 can be reduced. This can reduce the light that does not enter the sensor 30, out of the detection light L4 emitted from the prism unit 22. That is, the light receiving efficiency of the sensor 30 can be improved. Further, the detection accuracy of the position of the optical member 20 in the rotation direction E can be improved. That is, the accuracy of detecting the origin position of the optical member 20 can be improved.

In the 6 th place, the light irradiation device 1 has the prism portion 22, and thus the light irradiation device 1 can perform the operation of returning the optical member 20 to the original position with a small amount of light. Further, the light irradiation device 1 can reduce the influence of the unexpected movement of the irradiation light L3 on the irradiation surface.

1-4 variation of embodiment 1

Fig. 5 (a) and 5 (B) are a front view and a side view schematically showing an optical member 50 of a light irradiation device according to modification 1 of embodiment 1. Fig. 6 is a front view schematically showing light guide part 53 of optical member 50 shown in fig. 5 (a). The light irradiation device according to modification 1 is different from the light irradiation device 1 shown in fig. 1 to 4 in the shape of the light emitting end of the light guide portion 53 of the optical member 50. Except for this point, the light irradiation device of modification 1 of embodiment 1 is the same as the light irradiation device 1 shown in fig. 1 to 4. The same components as those of the light irradiation device 1 are denoted by the same reference numerals, and description thereof is omitted.

The components 51, 51a, and 51b correspond to the components 21, 21a, and 21b, respectively. The components 52, 52a, and 52b correspond to the components 22, 22a, and 22b, respectively. These components are explained by the light irradiation device 1 instead of the modification 1.

Light guide portion 53 corresponds to light guide portion 23. The light emitting end portions 54, 55, and 56 of the light guide portion 53 have different structures from the light emitting end portions 24 and 25 of the light guide portion 23. Light guide portion 53 other than this point is described with light guide portion 23 instead of light guide portion 53.

As shown in fig. 5 (a) and 6, the light guide portion 53 has a light exit end portion 54, a light exit end portion 55, and a light exit end portion 56. The light emitting end 54 emits the detection light L41 a. The light emitting end 55 emits the detection light L42 a. The light emitting end 56 emits the detection light L43 a. The light output surface 54a of the light output end 54, the light output surface 55a of the light output end 55, and the light output surface 56a of the light output end 56 have different areas. The areas of the light output surfaces 54a, 55a, and 56a are areas of regions from which the detection lights L41a, L42a, and L43a are emitted.

The amounts of the detection light L41a, the detection light L42a, and the detection light L43a emitted from the light emitting end 54, the light emitting end 55, and the light emitting end 56 are different from each other. In fig. 5 (a) and 6, for example, the ratio of the amounts of the detection light L41a, the detection light L42a, and the detection light L43a emitted from the light emitting end portion 54, the light emitting end portion 55, and the light emitting end portion 56 is set to 1: 3: light guide portion 53 is formed in the manner of 2. The light amount of the detection light L43a is, for example, 2 times the light amount of the detection light L41 a. The light amount of the detection light L42a is, for example, 3 times the light amount of the detection light L41 a.

Fig. 7 (a) and 7 (C) are diagrams illustrating a positional relationship between the light guide portion 53 of the optical member 50 and the sensor 30 shown in fig. 5 (a). Fig. 7 (B) and 7 (D) are diagrams illustrating the shape of the light receiving part 30B of the sensor 30 illustrated in fig. 5 (a).

Fig. 7 (a) shows the case of the position P4. At the position P4, the light emitting end 54 and the light emitting end 55 face the light receiving portion 30b of the sensor 30. Fig. 7 (C) shows the case of the position P5. At the position P5, the light emitting end 55 and the light emitting end 56 face the light receiving portion 30b of the sensor 30.

For example, the range of the light emitting surface of the light emitting end portion in which the light emitting surface 54a of the light emitting end portion 54 and the light emitting surface 55a of the light emitting end portion 55 are combined is a range of a rectangular shape in which the circumferential length of the optical member 50 is W2 and the z-axis direction length is D2. The length D2 is the length of the optical member 50 in the thickness direction. Similarly, the range of the light emitting surface of the light emitting end portion, which is formed by combining the light emitting surface 55a of the light emitting end portion 55 and the light emitting surface 56a of the light emitting end portion 56, is a rectangular range having a circumferential length W2 and a z-axis direction length D2 of the optical member 50.

The rectangular range corresponds to, for example, the range of the light receiving unit 30b of the sensor 30. The range of the light receiving unit 30b of the sensor 30 is a rectangular range having a length W2 corresponding to the circumferential direction of the optical member 50 and a length D2 in the z-axis direction. In the figure, the length corresponding to the circumferential direction of the optical member 50 is the length in the x-axis direction.

As shown in fig. 7 (a) and 7 (B), the light emitting end 54 and the light emitting end 55 receive the light amount I1 when they face the light receiving portion 30B of the sensor 30. The light amount I1 is the sum of the light amount of the detection light L41a emitted from the light emitting end 54 and the light amount of the detection light L42a emitted from the light emitting end 55.

As shown in fig. 7 (C) and 7 (D), the light emitting end 55 and the light emitting end 56 receive the light amount I2 when they face the light receiving portion 30b of the sensor 30. The light amount I2 is the sum of the light amount of the detection light L42a emitted from the light emitting end 55 and the light amount of the detection light L43a emitted from the light emitting end 56.

When the ratio of the light amounts of the detection light L41a, the detection light L42a, and the detection light L43a is 1: 3: 2, I1: i2 ═ 4: 5. that is, the light amount I2 was 1.25 times the light amount I1.

The light irradiation device according to modification 1 has a value of the light amount I1 different from a value of the light amount I2. Therefore, the light irradiation device can recognize the position P4 at which the light amount I1 is detected and the position P5 at which the light amount I2 is detected. Therefore, when fine adjustment of the origin position of the optical member 50 in the rotation direction E is required, any one of the plurality of positions P4 and P5 can be set as the origin position.

Variation 2 of embodiment 1 of (1-5)

Fig. 8 (a) and 8 (B) are a front view and a side view schematically showing an optical member 60 of a light irradiation device according to modification 2 of embodiment 1. Fig. 9 (a) is a front view schematically showing light guide unit 63 of optical member 60 shown in fig. 8 (a). Fig. 9 (B) is a plan view of the light emitting end of the light guide unit 63.

The light irradiation device according to modification 2 of embodiment 1 differs from the light irradiation device 1 shown in fig. 1 to 4 in the shape of the light guide portion 63 of the optical member 60 and the size of the light receiving portion 30b of the sensor 30 a. Except for these points, the light irradiation device according to modification 2 of embodiment 1 is the same as the light irradiation device 1 shown in fig. 1 to 4. The same components as those of the light irradiation device 1 are denoted by the same reference numerals, and description thereof is omitted.

The components 61, 61a, and 61b correspond to the components 21, 21a, and 21b, respectively. Components 62, 62a, and 62b correspond to components 22, 22a, and 22b, respectively. The description of the light irradiation device 1 replaces the description of the modification 2 with respect to these components.

Light guide portion 63 corresponds to light guide portion 23. The light emitting end portions 64, 65, and 66 of the light guide portion 63 have different structures from the light emitting end portions 24 and 25 of the light guide portion 23. In light guide portion 63 other than this, the description of light guide portion 23 is used instead of the description of light guide portion 63.

As shown in fig. 8 (a), 9 (a), and 9 (B), the light guide part 63 has a light emitting end 64, a light emitting end 65, and a light emitting end 66. The light emitting surface 64a of the light emitting end portion 64, the light emitting surface 65a of the light emitting end portion 65, and the light emitting surface 66a of the light emitting end portion 66 have the same area. The areas of the light output surfaces 64a, 65a, and 66a are areas of regions from which the detection lights L41b, L42b, and L43b are emitted.

The amounts of the detection light L41b, the detection light L42b, and the detection light L43b emitted from the light emitting end 64, the light emitting end 65, and the light emitting end 66 are different from each other.

In the circumferential direction of the optical member 60, the distance between the center of the light exit surface 64a of the light exit end portion 64 and the center of the light exit surface 65a of the light exit end portion 65 is F1. The distance between the center of the light exit surface 65a of the light exit end 65 and the center of the light exit surface 66a of the light exit end 66 is also F1. That is, the interval between the center of the light emitting surface 64a of the light emitting end portion 64 and the center of the light emitting surface 65a of the light emitting end portion 65 is equal to the interval between the center of the light emitting surface 65a of the light emitting end portion 65 and the center of the light emitting surface 66a of the light emitting end portion 66.

Further, the light guide portion 63 is provided with 2V-groove-shaped cutouts, thereby forming a light emitting end portion 64, a light emitting end portion 65, and a light emitting end portion 66. A V-groove shaped notch is formed between the light emitting end 64 and the light emitting end 65. A V-groove shaped notch is formed between the light emitting end 65 and the light emitting end 66.

As shown in fig. 9 (a), at the bottom of the 2 cutout portions of the light guide portion 63, the circumferential lengths of the portions divided into 3 are W4, W5, and W6. The length of the light entrance portion 64b of the light exit end portion 64 in the circumferential direction is W4. The length of the light entrance portion 65b of the light exit end portion 65 in the circumferential direction is W5. The length of the light entrance portion 66b of the light exit end portion 66 in the circumferential direction is W6. In fig. 9, the circumferential direction is the x-axis direction. The ratio of the circumferential length of the portion divided into 3 at the bottom of the 2 cutouts of light guide portion 63 is W4: w5: w6. The notch is in the shape of a V-shaped groove. The 3-divided portions include a portion having the light emitting end 64, a portion having the light emitting end 65, and a portion having the light emitting end 66. The light emitting ends 64, 65, and 66 have the same dimension in the thickness direction. In fig. 9, the thickness direction is the y-axis direction.

Therefore, the ratio of the cross-sectional area of the portion divided into 3 at the bottom of the 2 cutouts of light guide portion 63 is also W4: w5: w6. The light entrance part 64b is located at the bottom of the cutout part in the light exit end part 64. The light entrance portion 65b is located at the bottom of the cutout portion in the light exit end portion 65. The light entrance part 66b is located at the bottom of the cutout part in the light emission end part 66. That is, the ratio of the areas of the light incident part 64b, the light incident part 65b, and the light incident part 66b is W4: w5: w6. In this case, the ratio of the light amounts of the detection light L41b, the detection light L42b, and the detection light L43b emitted from the light emitting end 64, the light emitting end 65, and the light emitting end 66 is W4: w5: w6. The light emitting surfaces 64a, 65a, and 66a of the light guide unit 63 have the same area. The light guide unit 63 has different light incident portions 64b, 65b, and 66b in area. The light amount of each of the detection lights L41b, L42b, and L43b is proportional to the area of the light incident portion 64b, 65b, or 66 b. In addition, it is considered that the distribution of the amount of light incident on the light guide portion 63 is uniform.

Fig. 10 (a) to 10 (C) are views showing the positional relationship between the light guide portion 63 of the optical member 60 shown in fig. 8 (a) and the sensor 30 a. Positions P6, P7, and P8 are shown in fig. 10 (a) to 10 (C). The positions P6, P7, and P8 are positions of the light emitting ends 64, 65, and 66 with respect to the sensor 30 when the optical member 60 rotates about the rotation axis AR.

Fig. 10 (a) shows a case where the position of the optical member 60 in the rotation direction E is the position P6. Fig. 10 (B) shows a case where the position of the optical member 60 in the rotation direction E is the position P7. Fig. 10 (C) shows a case where the position of the optical member 60 in the rotation direction E is the position P8.

The shape of the light receiving part 30b of the sensor 30a is the same as the shape of the light emitting surface 64a of the light emitting end part 64, the shape of the light emitting surface 65a of the light emitting end part 65, and the shape of the light emitting surface 66a of the light emitting end part 66. For example, when the area of the light receiving part 30b of the sensor 30a is the area S, the area of the light emitting surface 64a of the light emitting end part 64, the area of the light emitting surface 65a of the light emitting end part 65, and the area of the light emitting surface 66a of the light emitting end part 66 may be set to the area S. The area S of the light receiving part 30b of the sensor 30a may be larger than the area of the light emitting surface 64a of the light emitting end part 64, the area of the light emitting surface 65a of the light emitting end part 65, and the area of the light emitting surface 66a of the light emitting end part 66.

However, it is preferable that the area in which the detection light cannot be simultaneously received from the plurality of light emitting ends of the light emitting end 64, the light emitting end 65, and the light emitting end 66. That is, the light receiving unit 30b of the sensor 30a is preferably not large enough to simultaneously receive the detection light L41b emitted from the light emitting end 64 and the detection light L42b emitted from the light emitting end 65.

At the position P6, the light emitting end 64 faces the sensor 30 a. The light emitting end 65 and the light emitting end 66 do not face the sensor 30 a. The detection light L41b emitted from the light emitting end 64 reaches the sensor 30 a. The detection light L42b emitted from the light emitting end 65 and the detection light L43b emitted from the light emitting end 66 do not reach the sensor 30 a. Therefore, the light receiving amount of the sensor 30a is the amount of the detection light L41b emitted from the light emitting end 64.

At the position P7, the light exit end 64 does not face the sensor 30 a. The light emitting end 65 faces the sensor 30 a. The light emitting end 66 does not face the sensor 30 a. The detection light L41b emitted from the light emitting end 64 does not reach the sensor 30 a. The detection light L42b emitted from the light emitting end 65 reaches the sensor 30 a. The detection light L43b emitted from the light emitting end 66 does not reach the sensor 30 a. Therefore, the light receiving amount of the sensor 30a is the amount of the detection light L42b emitted from the light emitting end portion 65.

At the position P8, the light emitting end 64 and the light emitting end 65 do not face the sensor 30 a. The light emitting end 66 faces the sensor 30 a. The detection light L41b emitted from the light emitting end 64 and the detection light L42b emitted from the light emitting end 65 do not reach the sensor 30 a. The detection light L43b emitted from the light emitting end 66 reaches the sensor 30 a. Therefore, the light receiving amount of the sensor 30a is the amount of the detection light L43b emitted from the light emitting end 66.

In the light irradiation device according to modification 2, the amounts of the detection light L41b, the detection light L42b, and the detection light L43b emitted from the light emitting end portion 64, the light emitting end portion 65, and the light emitting end portion 66 are different from each other. Therefore, when fine adjustment of the origin position of the optical component 60 in the rotation direction E is required, any one of the plurality of positions P6, P7, and P8 can be set as the origin position.

EXAMPLE 2

Fig. 11 is a diagram schematically showing the configuration of a light irradiation device 2 according to embodiment 2 of the present invention. In fig. 11, the same reference numerals as those shown in fig. 1 (embodiment 1) are given to the same or corresponding components as those shown in fig. 1. Moreover, their description is omitted.

Fig. 12 (a) and 12 (B) are a front view and a side view schematically showing the optical member 70 of the light irradiation device 2 according to embodiment 2. The light irradiation device 2 of embodiment 2 differs from the light irradiation device 1 of embodiment 1 in the structure of the optical member 70. Except for this point, the light irradiation device 2 of embodiment 2 is the same as the light irradiation device 1 of embodiment 1.

Components 71, 71a, and 71b correspond to components 21, 21a, and 21b, respectively. The description of the light irradiation device 1 is replaced with the description of the light irradiation device 2 for these components. Components 72, 72a, and 72b correspond to components 22, 22a, and 22b, respectively. The prism portion 72 has a different structure from the prism portion 22.

As shown in fig. 11, fig. 12 (a), and fig. 12 (B), for example, parallel light is incident on the optical member 70. The optical member 70 includes a prism portion 71 and a prism portion 72. The prism portion 71 emits irradiation light L2. The light distribution of the irradiation light L2 changes depending on the position of the optical member 70 in the rotation direction E. The prism portion 72 emits the detection light L5. The detection light L5 is emitted in an emission direction corresponding to the position of the optical member 70 in the rotation direction E. The optical member 70 deflects the incident light L1, and emits the irradiation light L2 and the detection light L5. The optical member 70 converts the incident light L1 into the irradiation light L2 and the detection light L5.

As shown in fig. 12 (a) and 12 (B), the prism portion 71 is a wedge prism. The prism portion 71 has a surface 71a and a surface 71 b. The surface 71a and the surface 71b are disposed opposite to each other.

The surface 71a is formed on the light incident surface side of the optical member 70. The surface 71a is formed on the light incident surface of the optical member 70, for example. The surface 71a is formed on the light source 11 side. The face 71a is, for example, a flat face. The plane 71a has an intersection with the rotation axis AR.

The surface 71b is formed on the light exit surface side of the optical member 70. The surface 71b is formed on the light exit surface of the optical member 70, for example. The face 71b is, for example, a flat face. The plane 71b has an intersection with the rotation axis AR.

The face 71a and the face 71b are inclined faces to each other. The face 71a is inclined with respect to the rotation axis AR. In fig. 11 and 12 (B), the surface 71a is parallel to the x axis and inclined to the y axis. The surface 71b is a surface perpendicular to the rotation axis AR. The surface 71b is parallel to both the x-axis and the y-axis. With respect to the thickness of the prism portion 71, the-y axis side is thicker than the + y axis side. Therefore, the light incident on the prism portion 71 is deflected toward the-y axis.

Light L1 enters surface 71 a. The light L1 incident on the surface 71a is, for example, light parallel to the z-axis. The rotation axis AR is parallel to the z-axis. Light L1 is refracted at surface 71 a. The light L1 refracted at the surface 71a is refracted at the surface 71 b. The light L1 refracted at the surface 71b is emitted from the surface 71b as the irradiation light L2. The irradiation light L2 is light inclined with respect to the rotation axis AR. The irradiation light L2 is light inclined with respect to the z-axis.

The traveling direction of the irradiation light L2 changes depending on the position of the optical member 70 in the rotation direction E. That is, the light distribution of the irradiation light L2 changes depending on the position of the optical member 70 in the rotation direction E.

However, the surface 71a may be a surface perpendicular to the rotation axis AR, and the surface 71b may be a surface inclined with respect to the rotation axis AR. That is, the surface 71a may be a surface parallel to both the x-axis and the y-axis, and the surface 71b may be a surface parallel to the x-axis and inclined to the y-axis. In this case, light L1 parallel to the z-axis enters surface 71a perpendicularly. Light L1 enters surface 71a and is refracted at surface 71 b. The light L1 refracted at the surface 71b is emitted from the surface 71b as the irradiation light L2. The irradiation light L2 is light inclined with respect to the rotation axis AR. The irradiation light L2 is light inclined with respect to the z-axis.

The prism section 72 extracts the detection light L5 from the incident light L1. The prism unit 72 is a prism for detecting light.

The prism portion 72 is formed on the outer peripheral side of the optical component 70 with the rotation axis AR as the center. The prism portion 72 is formed on the outer peripheral portion of the optical member 70 centered on the rotation axis AR. The prism portion 72 is formed, for example, in a thick portion of the prism portion 71. The prism portion 72 is formed, for example, in a portion having a thickness greater than the average wall thickness of the prism portion 71. The prism portion 72 is formed, for example, at the thickest part of the prism portion 71.

As shown in fig. 12 (a) and 12 (B), the prism portion 72 has a surface 72a and a surface 72B. The faces 72a and 72b are oppositely disposed.

The surface 72a is formed on the light incident surface side of the optical member 20. The surface 72a is formed on the light incident surface of the optical member 20, for example. The surface 72a is formed on the light source 11 side. The surface 72a may be, for example, the same surface as the surface 71 a. As shown in fig. 12 (B), the surface 72a may be formed on the same surface as the surface 71a, for example. The face 72a is, for example, a flat face.

The surface 72b is formed on the light exit surface side of the optical member 20. The surface 72b is formed on the light exit surface of the optical member 20, for example. The face 22b is, for example, a plane.

The faces 72a and 72b are inclined faces to each other. The face 72b is inclined with respect to the face 71 b. The face 72a is inclined with respect to the rotation axis AR. In fig. 11 and 12 (B), the surface 72a is parallel to the x axis and inclined to the y axis. The surface 72b is a surface inclined with respect to the rotation axis AR. The face 72b is parallel to the x-axis and oblique to the y-axis.

In the direction of the rotation axis AR, the outer peripheral side of the surface 72a centered on the rotation axis AR is positioned closer to the light source 11 than the inner peripheral side. The light source 11 side is the-z-axis side. In the direction of the rotation axis AR, the outer peripheral side of the surface 72a centered on the rotation axis AR protrudes in the direction (the (-z-axis direction) opposite to the direction (+ z-axis direction) in which the light L1 enters, than the inner peripheral side. That is, in the direction of the rotation axis AR, the outer peripheral side of the surface 72a centered on the rotation axis AR protrudes more upstream in the traveling direction of the light L1 than the inner peripheral side. In the direction of the rotation axis AR, the outer peripheral side of the surface 72b centered on the rotation axis AR protrudes further toward the light exit direction of the light L2 than the inner peripheral side. The emission direction side is the + z-axis direction side.

As shown in fig. 11, the light L1 is, for example, light parallel to the z-axis. The light L1 is, for example, light parallel to the rotation axis AR. Light L1 is incident on surface 72 a. Light L1 is refracted at surface 72 a. The light L1 is refracted at the surface 72a of the prism portion 72. The light L1 is refracted toward the outer peripheral side of the optical component 70 around the rotation axis AR.

The light L1 refracted at the surface 72a is reflected at the surface 72 b. The light L1 refracted at the surface 72a is totally reflected at the surface 72b, for example. The light L1 refracted at the surface 72a is reflected toward the outer peripheral side of the optical component 70 around the rotation axis AR. The light L1 reflected by the surface 72b travels toward the outer periphery of the optical component 70. Light L1 reflected on surface 72b is emitted from side surface 74 of prism 72 as detection light L5. The light L1 reflected on the surface 72b is emitted from the side surface of the optical member 70 as detection light L5. The side surface 74 is a surface on the outer peripheral side with the rotation axis AR as the center.

The prism portion 72 does not have a light guide portion radially outward of the rotation axis AR. However, similarly to embodiment 1, the light guide portion may be provided.

The lens barrel 35 holds an optical member 70. The lens barrel 44 holds the wedge prism 41. The lens barrel 35 has an opening 36. The lens barrel 44 has an opening 45. The position of the opening 45 in the z-axis direction is the same as the position of the opening 36 in the z-axis direction. The lens barrel 35 is rotated with respect to the lens barrel 44. The circumferential position of the opening 45 is matched with the circumferential position of the opening 36. The opening 45 is located opposite to the opening 36. The position of the opening 45 relative to the opening 36 is, for example, the origin position.

At this time, the detection light L5 emitted from the side surface 74 of the prism portion 72 passes through the opening 36 to reach the opening 45. The detection light L5 emitted from the side surface 74 of the prism portion 72 passes through the opening 45 to reach the sensor 30. That is, the detection light L5 emitted from the side surface 74 of the prism portion 72 passes through the opening 45 and enters the light receiving portion 30b of the sensor 30. Here, the detection light L4 is light deflected by the prism unit 72 and emitted from the side surface 74 of the prism unit 72. In the optical member 70, the side surface 74 of the prism portion 72 is the side surface of the optical member 70.

The sensor 30 receives the detection light L5. The sensor 30 receives the detection light L5 of the light amount corresponding to the position of the optical member 70 in the rotation direction E. The sensor 30 receives the detection light L5 deflected by the prism portion 72. The sensor 30 receives the deflected detection light L5, thereby detecting the position of the optical member 70 in the rotation direction E. The sensor 30 can detect, for example, the origin position in the rotation direction E of the optical member 70.

As described above, the light irradiation device 2 can detect the position of the optical member 70 in the rotation direction E using the light L0 emitted from the light source 11. In this way, the light irradiation device 2 can detect the position of the optical member 70 in the rotation direction E with a simple configuration. The position of the optical member 70 in the rotation direction E is, for example, an origin position.

Further, the light irradiation device 2 does not have a light guide portion, and thus the structure can be further simplified.

EXAMPLE 3

Fig. 13 is a diagram schematically showing the configuration of a light irradiation device 3 according to embodiment 3 of the present invention. In fig. 13, the same reference numerals as those shown in fig. 1 (embodiment 1) are given to the same or corresponding components as those shown in fig. 1. Moreover, their description is omitted.

Fig. 14 (a) and 14 (B) are a front view and a side view schematically showing an optical member 80 of a light irradiation device 3 according to embodiment 3. The light irradiation device 3 of embodiment 3 differs from the light irradiation device 1 of embodiment 1 in the structure of the optical member 80. In other words, the light irradiation device 3 of embodiment 3 differs from the light irradiation device 1 of embodiment 1 in that the optical member 80 does not have a light guide portion. Except for this point, the light irradiation device 3 of embodiment 3 is the same as the light irradiation device 1 of embodiment 1. In addition, the light irradiation device 1 will be described instead of the light irradiation device 3 except for the portion having no light guide portion.

As shown in fig. 13, fig. 14 (a), and fig. 14 (B), for example, parallel light is incident on the optical member 80. The optical member 80 includes a prism portion 81 and a prism portion 82. The optical member 80 deflects the incident light L1 and emits the irradiation light L2 and the detection light L6. The optical member 80 converts the incident light L1 into the irradiation light L2 and the detection light L6.

The prism portion 81 is a portion that changes the emission direction of the illuminating light L2. The prism portion 81 emits irradiation light L2. The light distribution of the irradiation light L2 changes depending on the position of the optical member 80 in the rotation direction E. When the optical member 80 rotates in the rotation direction E, the emission direction of the irradiation light L2 changes.

The prism section 82 extracts the detection light L6 from the incident light L1. The prism unit 82 is a prism for detecting light. The prism portion 82 emits the detection light L6 in an emission direction corresponding to the position of the optical member 80 in the rotation direction E.

The prism portion 81 corresponds to the prism portion 21. The surface 81a corresponds to the surface 21 a. The surface 81b corresponds to the surface 21 b. The prism portion 82 corresponds to the prism portion 22. The face 82a corresponds to the face 22 a. The face 82b corresponds to the face 22 b. The description of the light irradiation device 1 is replaced with the description of the light irradiation device 3 for these components.

As shown in fig. 14 (a) and 14 (B), the prism portion 81 is a wedge prism. The prism portion 81 has a surface 81a and a surface 81 b. The surface 81a and the surface 81b are disposed opposite to each other.

The face 81a and the face 81b are inclined faces to each other. The face 81a is inclined with respect to the face 81 b. The face 81a is inclined with respect to the rotation axis AR. In fig. 13 and 14 (B), the surface 81a is parallel to the x axis and inclined to the y axis. The surface 81b is, for example, a surface perpendicular to the rotation axis AR. The surface 81b is parallel to both the x-axis and the y-axis. With respect to the thickness of the prism portion 81, the-y axis side is thicker than the + y axis side. Therefore, the light incident on the prism portion 81 is deflected toward the-y axis.

Light L1 enters surface 81 a. The light L1 incident on the surface 81a is, for example, light parallel to the z axis. Light L1 is refracted at surface 81 a. The light L1 refracted at the surface 81a is refracted at the surface 81 b. The light L1 refracted at the surface 81b is emitted from the surface 81b as the irradiation light L2. The irradiation light L2 is light inclined with respect to the rotation axis AR. The irradiation light L2 is light inclined with respect to the z-axis.

The traveling direction of the irradiation light L2 changes depending on the position of the optical member 80 in the rotation direction E. That is, the light distribution of the irradiation light L2 changes depending on the position of the optical member 80 in the rotation direction E.

However, the surface 81a may be a surface perpendicular to the rotation axis AR, and the surface 81b may be a surface inclined with respect to the rotation axis AR. That is, the surface 81a may be a surface parallel to both the x axis and the y axis, and the surface 81b may be a surface parallel to the x axis and inclined to the y axis. In this case, light L1 parallel to the z-axis enters surface 81a perpendicularly. Light L1 enters surface 81a and is refracted at surface 81 b. The light L1 refracted at the surface 81b is emitted from the surface 81b as the irradiation light L2. The irradiation light L2 is light inclined with respect to the rotation axis AR. The irradiation light L2 is light inclined with respect to the z-axis.

The prism section 82 extracts the detection light L6 from the incident light. The prism unit 82 is a prism for detecting light.

The prism portion 82 is formed on the outer peripheral side of the optical component 80 with the rotation axis AR as the center. The prism portion 82 is formed on the outer peripheral portion of the optical member 80 centered on the rotation axis AR. The prism portion 82 is formed, for example, in a portion of the prism portion 81 having a small thickness. The prism portion 82 is formed, for example, in a portion having a thickness smaller than the average wall thickness of the prism portion 81. The prism portion 82 is formed, for example, at a portion where the thickness of the prism portion 81 is the thinnest.

As shown in fig. 14 (a) and 14 (B), the prism portion 82 has a surface 82a and a surface 82B. The faces 82a and 82b are disposed opposite to each other.

The face 82a and the face 82b are faces inclined to each other. The face 82b is inclined with respect to the face 81 b. The surface 82a is a surface inclined with respect to the rotation axis AR. In fig. 13 and 14 (B), the surface 82a is parallel to the x axis and inclined to the y axis. As shown in fig. 14 (B), the surface 82a is inclined in the opposite direction to the surface 81 a. The surface 82b is, for example, a surface perpendicular to the rotation axis AR. The surface 82b is parallel to both the x-axis and the y-axis.

In the direction of the rotation axis AR, the outer peripheral side of the surface 82a centered on the rotation axis AR is positioned closer to the light source 11 than the inner peripheral side. In the direction of the rotation axis AR, the outer peripheral side of the surface 82a centered on the rotation axis AR protrudes further toward the direction in which the light L1 enters than the inner peripheral side. The direction side in which the light L1 is incident is the-z-axis direction side. The outer peripheral side of the surface 82a around the rotation axis AR protrudes in the direction opposite to the direction (+ z-axis direction) in which the light L1 enters (i.e., the (-z-axis direction) than the inner peripheral side. That is, in the direction of the rotation axis AR, the outer peripheral side of the surface 82a centered on the rotation axis AR protrudes more upstream in the traveling direction of the light L1 than the inner peripheral side.

As shown in fig. 13, the light L1 is, for example, light parallel to the z-axis. The light L1 is, for example, light parallel to the rotation axis AR. Light L1 is incident on surface 82 a. Light L1 is refracted at surface 82 a. The light L1 is refracted at the surface 82a of the prism 82. The light L1 is refracted toward the outer peripheral side of the optical component 80 centered on the rotation axis AR.

The light L1 refracted at the surface 82a is reflected at the surface 82 b. The light L1 refracted at the surface 82a is totally reflected at the surface 82b, for example. The light L1 refracted at the surface 82a is reflected toward the outer peripheral side of the optical component 80 centered on the rotation axis AR. The light L1 reflected by the surface 82b travels toward the outer periphery of the optical component 80. The light L1 reflected on the surface 82b is emitted from the side surface 84 of the prism 82 as the detection light L6. The side surface 84 is a surface on the outer peripheral side with the rotation axis AR as the center. The side surface 84 of the prism portion 82 is, for example, a side surface of the optical member 80.

However, the prism portion 82 may have a surface 82a parallel to both the x-axis and the y-axis and a surface 82b parallel to the x-axis and inclined to the y-axis. In the direction of the rotation axis AR, the outer peripheral side of the surface 82b centered on the rotation axis AR protrudes further toward the light exit direction of the light L2 than the inner peripheral side. The emission direction side is the + z-axis direction side. In this case, incident light L1 parallel to the z-axis enters from the surface 82 a. Then, the light L1 is reflected on the surface 82b and is emitted from the side surface 84 of the prism 82 as the detection light L6.

The lens barrel 35 holds the optical member 80. The lens barrel 44 holds the wedge prism 41. The lens barrel 35 has an opening 36. The lens barrel 44 has an opening 45.

The position of the opening 45 in the z-axis direction is the same as the position of the opening 36 in the z-axis direction. The position of the opening 45 in the rotation axis AR direction is the same as the position of the opening 36 in the rotation axis AR direction. The lens barrel 35 is rotated with respect to the lens barrel 44. The circumferential position of the opening 45 is matched with the circumferential position of the opening 36. The opening 45 is located opposite to the opening 36. The position of the opening 45 relative to the opening 36 is, for example, the origin position.

At this time, the detection light L6 emitted from the side surface 84 of the prism portion 82 passes through the opening 36 to reach the opening 45. The detection light L6 emitted from the side surface 84 of the prism portion 82 passes through the opening 45 to reach the sensor 30. That is, the detection light L6 emitted from the side surface 84 of the prism portion 82 passes through the opening 45 and enters the light receiving portion 30b of the sensor 30. Here, the detection light L6 is light deflected by the prism portion 82 and emitted from the side surface 84 of the prism portion 82. In the optical member 80, for example, the side surface 84 of the prism portion 82 is the side surface of the optical member 80.

The sensor 30 receives the detection light L6 of the light amount corresponding to the position of the optical member 80 in the rotation direction E. The sensor 30 receives the detection light L6 deflected by the prism portion 82. The sensor 30 receives the deflected detection light L6, thereby detecting the position of the optical member 80 in the rotation direction E. The sensor 30 can detect, for example, the origin position in the rotation direction E of the optical member 80.

As described above, the light irradiation device 3 can detect the position of the optical member 80 in the rotation direction E using the light L0 emitted from the light source 11. In this way, the light irradiation device 3 can detect the position of the optical member 80 in the rotation direction E with a simple configuration. The position of the optical member 80 in the rotation direction E is, for example, an origin position.

Further, the light irradiation device 3 does not have a light guide portion, and thus the structure can be further simplified.

In the above embodiments, terms such as "parallel", "perpendicular", and "center" may be used to indicate the positional relationship between components and the shapes of the components. The ranges expressed by these terms are ranges in consideration of manufacturing tolerances, assembly variations, and the like. Therefore, when the claims describe the positional relationship between the components and the shapes of the components, the description includes a range in consideration of manufacturing tolerances, assembly variations, and the like.

While the embodiments of the present invention have been described above, the present invention is not limited to these embodiments.

According to the above embodiments, the following description of the invention is given as reference (1), reference (2), and reference (3). The attached mark (1), the attached mark (2) and the attached mark (3) are respectively marked with labels independently. Therefore, for example, "supplementary note 1" exists in supplementary notes (1), (2), and (3), respectively. Further, the features of note (1), the features of note (2), and the features of note (3) can be combined with each other.

< 4> attach memory (1)

< appendix 1>

A light irradiation device includes:

a 1 st light source that emits light;

a wedge prism that receives the light emitted from the 1 st light source and deflects and emits the light, and that is supported so as to be rotatable about a rotation axis; and

a sensor that detects a position of the wedge prism in a rotational direction,

the wedge prism has a prism on an outer peripheral portion centered on the rotation axis,

the prism deflects the incident light emitted from the 1 st light source toward the outer circumferential direction of the wedge prism,

the sensor receives the light deflected by the prism.

< appendix 2>

The light irradiation apparatus according to supplementary note 1, wherein,

the wedge prism has a light guide portion on an outer peripheral side of the prism, the light guide portion guiding light deflected by the prism to the sensor.

< appendix 3>

The light irradiation apparatus according to supplementary note 2, wherein,

the light guide portion includes a plurality of light exit end portions arranged side by side in a rotational direction of the wedge prism,

the sensor sequentially receives light emitted from the light emitting end according to rotation of the wedge prism.

< appendix 4>

The light irradiation apparatus according to supplementary note 3, wherein,

the light quantity emitted from the plurality of light emitting ends is equal.

< appendix 5>

The light irradiation apparatus according to supplementary note 3, wherein,

the light quantity emitted from the plurality of light emitting ends is different.

& lt 5 & gt, attached memory (2)

< appendix 1>

A light irradiation device is characterized by comprising:

a light source that emits light;

an optical member that is supported so as to be rotatable about a rotation axis and emits irradiation light based on the light and detection light based on the light; and

the sensor is provided with a sensor which is used for detecting the position of the sensor,

the optical component includes:

a 1 st prism portion that emits the irradiation light whose light distribution changes depending on a position of the optical member in a rotation direction; and

a 2 nd prism portion that guides the detection light in an emission direction corresponding to the position in the rotation direction,

the sensor receives the detection light of an amount of light corresponding to the position in the rotation direction.

< appendix 2>

The light irradiation device according to supplementary note 1, wherein,

the 1 st prism part is a wedge prism.

< appendix 3>

The light irradiation apparatus according to supplementary note 1 or 2, characterized in that,

the 2 nd prism portion is disposed on an outer peripheral side of the optical component.

< appendix 4>

A light irradiation device according to any one of supplementary notes 1 to 3, characterized in that,

the 2 nd prism portion emits the detection light radially outward of the optical member.

< appendix 5>

A light irradiation device according to any one of supplementary notes 1 to 4, characterized in that,

the optical member includes a light guide portion that guides the detection light to an outer side in a radial direction of the optical member.

< appendix 6>

The light irradiation device according to supplementary note 5, wherein,

the light guide portion includes a 1 st light emission end portion and a 2 nd light emission end portion arranged in parallel in a rotation direction of the optical member,

the sensor receives, based on the position in the rotational direction, either a 1 st detection light, which is the detection light emitted from the 1 st light emitting end, a 2 nd detection light, which is the detection light emitted from the 2 nd light emitting end, or both the 1 st detection light and the 2 nd detection light.

< appendix 7>

The light irradiation device according to supplementary note 6, wherein,

the light amount of the 1 st detection light and the light amount of the 2 nd detection light are equal to each other.

< appendix 8>

The light irradiation device according to supplementary note 6, wherein,

the light amount of the 1 st detection light and the light amount of the 2 nd detection light are different from each other.

< appendix 9>

The light irradiation device according to supplementary note 5, wherein,

the light guide portion includes a 1 st light emitting end portion, a 2 nd light emitting end portion, and a 3 rd light emitting end portion arranged in parallel in the rotation direction,

the sensor receives, based on the position in the rotational direction, 1 st detection light, which is the detection light emitted from the 1 st light emitting end, 2 nd detection light, which is the detection light emitted from the 2 nd light emitting end, or 3 rd detection light, which is the detection light emitted from the 3 rd light emitting end.

< appendix 10>

The light irradiation device according to supplementary note 9, wherein,

the areas of the 1 st light exit end portion, the 2 nd light exit end portion and the 3 rd light exit end portion are different from each other,

the light amount of the 1 st detection light, the light amount of the 2 nd detection light, and the light amount of the 3 rd detection light are different from each other.

< appendix 11>

The light irradiation device according to supplementary note 9, wherein,

the areas of the 1 st light exit end portion, the 2 nd light exit end portion and the 3 rd light exit end portion are the same as each other,

the light amount of the 1 st detection light, the light amount of the 2 nd detection light, and the light amount of the 3 rd detection light are different from each other.

& lt 6 & gt, attached memory (3)

< appendix 1>

A light irradiation device is characterized by comprising:

a light source that emits light;

an optical member that is supported so as to rotate about a rotation axis and includes a 1 st prism portion that emits a 1 st detection light based on the light; and

a sensor that receives the 1 st detection light, detects a light amount of the 1 st detection light,

the light amount of the 1 st detection light received by the sensor changes according to the position of the rotation direction when the optical member rotates.

< appendix 2>

The light irradiation device according to supplementary note 1, wherein,

the 1 st prism portion is disposed on an outer peripheral portion of the optical member around the rotation axis.

< appendix 3>

The light irradiation apparatus according to supplementary note 1 or 2, characterized in that,

the light is incident to the optical component along the rotation axis.

< appendix 4>

A light irradiation device according to any one of supplementary notes 1 to 3, characterized in that,

the 1 st prism unit deflects the incident light and emits the deflected light as the 1 st detection light.

< appendix 5>

A light irradiation device according to any one of supplementary notes 1 to 4, characterized in that,

the 1 st prism portion emits the 1 st detection light to a radial direction outer side of the optical member with the rotation axis as a center.

< appendix 6>

The light irradiation device according to any one of supplementary notes 1 to 5, wherein,

the 1 st prism part includes a 1 st surface on which the light is incident and a 2 nd surface arranged to face the 1 st surface,

the 2 nd surface reflects the incident light to a radially outer side of the optical member with the rotation axis as a center.

< appendix 7>

The light irradiation apparatus according to supplementary note 6, wherein,

the 2 nd surface is a surface inclined with respect to the rotation axis.

< appendix 8>

The light irradiation apparatus according to supplementary note 6 or 7, wherein,

the 1 st surface refracts the incident light to a radially outer side of the optical member with respect to the rotation axis.

< appendix 9>

The light irradiation device according to any one of supplementary notes 6 to 8, wherein,

the 1 st surface is a surface inclined with respect to the rotation axis.

< appendix 10>

The light irradiation device according to any one of supplementary notes 6 to 9, wherein,

the 1 st surface is formed on a surface side of the optical member on which light is incident.

< appendix 11>

The light irradiation device according to any one of supplementary notes 1 to 10, wherein,

the light receiving part of the sensor is disposed at a position facing a surface of the 1 st prism part from which the 1 st detection light is emitted.

< appendix 12>

The light irradiation device according to any one of supplementary notes 1 to 10, wherein,

the optical member includes a light guide portion that guides the 1 st detection light to a light receiving portion of the sensor.

< appendix 13>

The light irradiation apparatus according to supplementary note 12, wherein,

the light guide portion guides the 1 st detection light to a radial direction outer side of the optical member with the rotation axis as a center.

< appendix 14>

A light irradiation apparatus according to supplementary note 12 or 13, characterized in that,

the light guide portion includes a 1 st light emission end portion and a 2 nd light emission end portion arranged in parallel in a rotation direction of the optical member,

the 1 st detection light includes 2 nd detection light and 3 rd detection light,

the 1 st light emitting end emits the 2 nd detection light,

the 2 nd light emitting end emits the 3 rd detection light,

the sensor detects the light amount of the 1 st detection light based on the presence or absence of reception of the 1 st detection light and the reception of at least one of the 2 nd detection light and the 3 rd detection light.

< appendix 15>

The light irradiation device according to supplementary note 14, wherein,

the light amount of the 2 nd detection light and the light amount of the 3 rd detection light are equal to each other.

< appendix 16>

The light irradiation device according to supplementary note 14, wherein,

the light amount of the 2 nd detection light and the light amount of the 3 rd detection light are different from each other.

< appendix 17>

A light irradiation device according to any one of supplementary notes 14 to 16,

the area of the 1 st light emitting surface of the 1 st light emitting end from which the 2 nd detection light is emitted is equal to the area of the 2 nd light emitting surface of the 2 nd light emitting end from which the 3 rd detection light is emitted.

< appendix 18>

A light irradiation device according to any one of supplementary notes 14 to 16,

the area of the 1 st light emitting surface of the 1 st light emitting end from which the 2 nd detection light is emitted is different from the area of the 2 nd light emitting surface of the 2 nd light emitting end from which the 3 rd detection light is emitted.

< appendix 19>

A light irradiation device according to any one of supplementary notes 14 to 18,

the area of the 1 st light incident portion where the 2 nd detection light enters the 1 st light emitting end portion is equal to the area of the 2 nd light incident portion where the 3 rd detection light enters the 2 nd light emitting end portion.

< appendix 20>

A light irradiation device according to any one of supplementary notes 14 to 18,

the area of the 1 st light incident portion where the 2 nd detection light enters the 1 st light emitting end portion is different from the area of the 2 nd light incident portion where the 3 rd detection light enters the 2 nd light emitting end portion.

< appendix 21>

The light irradiation device according to any one of supplementary notes 12 to 20, wherein,

the light receiving part of the sensor is disposed at a position facing a surface of the light guide part from which the 1 st detection light is emitted.

< appendix 22>

The light irradiation device according to any one of supplementary notes 1 to 21, wherein,

the optical member includes a 2 nd prism portion that emits irradiation light based on the light,

the 2 nd prism unit changes the light distribution of the irradiation light according to a position in a rotation direction when the optical member rotates.

< appendix 23>

The light irradiation apparatus according to supplementary note 22, wherein,

the 2 nd prism unit deflects the incident light and emits the deflected light as the irradiation light.

< appendix 24>

The light irradiation apparatus according to supplementary note 22 or 23, wherein,

the 2 nd prism unit emits the irradiation light in a direction opposite to a direction in which the light is incident.

< appendix 25>

The light irradiation apparatus according to supplementary note 22 or 23, wherein,

the 2 nd prism unit includes a 3 rd surface having an intersection with the rotation axis and on which the light is incident, and a 4 th surface having an intersection with the rotation axis and disposed opposite to the 3 rd surface,

the incident light exits from the 4 th surface.

< appendix 26>

A light irradiation device according to any one of supplementary notes 22 to 25, wherein,

the 2 nd prism part is a wedge prism.

Description of the reference symbols

1.2, 3: a light irradiation device; 11: a light source; 11 a: a light emitting face; 12: a lens section; 13: a heat sink; 14: a lens barrel; 20. 50, 60, 70, 80: an optical member; 21. 51, 61, 71, 81: a prism section (wedge prism); 21a, 51a, 61a, 71a, 81 a: kneading; 21b, 51b, 61b, 71b, 81 b: kneading; 22. 52, 62, 72, 82: a prism unit (a prism for detecting light); 22a, 52a, 62a, 72a, 82 a: kneading; 22b, 52b, 62b, 72b, 82 b: kneading; 23. 53, 63: a light guide part; 24. 25: a light emitting end portion; 24a, 25 a: a light emitting surface; 24b, 25 b: a light incident part; 30. 30 a: a sensor; 30 b: a light receiving section; 31: a gear; 32: a gear; 33: a motor; 34: a motor control unit; 35: a lens barrel; 36: an opening; 41: a wedge prism; 42: a light incident surface; 43: a light emitting surface; 44: a lens barrel; 45: an opening; 54. 55, 56, 64, 65, 66: a light emitting end portion; 54a, 55a, 56a, 64a, 65a, 66 a: a light emitting surface; 54b, 55b, 56b, 64b, 65b, 66 b: a light incident surface; 74. 84: a side surface; 90: an image forming section; AP, AC: an optical axis; AR: a rotating shaft; e: a direction of rotation of the optical component; l0, L1: a light; l2, L3: irradiating light; l4, L5, L6: detecting light; l41, L41a, L41 b: detecting light; l42, L42a, L42 b: detecting light; l43a, L43 b: light is detected.