阅读说明：本技术 车辆用灯具 (Vehicle lamp ) 是由 大和田竜太郎 于 2019-07-18 设计创作，主要内容包括：本发明提供一种车辆用灯具。车辆用灯具的光的利用效率高,而且能够通过实现零件数的削减以及结构的简化而实现进一步的小型化。车辆用灯具包括：光源；将从光源射出的光朝向前方投影的投影光学系统；对准投影光学系统的后侧焦点而配置的液晶元件；被配置在液晶元件与投影光学系统之间的光路中而使特定的偏振成分的光穿过的第1偏振板；使从光源射出的光朝向液晶元件聚光的聚光光学系统；将从光源射出的光分离成包含一个偏振成分的第1光和包含另一偏振成分的第2光的偏振分束器；使第1光朝向液晶元件反射的反射光学系统；以及使第1光和第2光中的任意一个光的偏振方向旋转而使其与任意另一光的偏振方向一致的偏振旋转元件。(A vehicular lamp includes a light source, a projection optical system that projects light emitted from the light source forward, a liquid crystal element disposed so as to be aligned with a rear focal point of the projection optical system, a 1 st polarizing plate that is disposed in an optical path between the liquid crystal element and the projection optical system and transmits light of a specific polarization component, a condensing optical system that condenses the light emitted from the light source toward the liquid crystal element, a polarization beam splitter that separates the light emitted from the light source into 1 st light including polarization components and 2 nd light including another polarization component, a reflection optical system that reflects the 1 st light toward the liquid crystal element, and a polarization rotator that rotates a polarization direction of any light of the 1 st light and the 2 nd light to be aligned with a polarization direction of any other light.)

A vehicle light of the kind , comprising:

a light source that emits light;

a projection optical system that projects light emitted from the light source toward the front;

a liquid crystal element disposed in alignment with a rear focal point of the projection optical system, the liquid crystal element controlling an image of light projected by the projection optical system;

a 1 st polarizing plate disposed in an optical path between the liquid crystal element and the projection optical system to pass light of a specific polarization component;

a condensing optical system that condenses light emitted from the light source toward the liquid crystal element;

a polarization beam splitter which passes a 1 st light including polarization components among the light emitted from the light source and reflects a 2 nd light including another polarization component to perform separation;

a reflection optical system that reflects the 1 st light toward the liquid crystal element; and

and a polarization rotation element disposed on an optical path between the polarization beam splitter and the liquid crystal element, the polarization rotation element rotating a polarization direction of any of the 1 st light and the 2 nd light to a polarization direction of any other light.

2. The vehicular lamp according to claim 1,

the 1 st light and the 2 nd light are condensed at a common condensing point with each other.

3. The vehicular lamp according to claim 2,

the liquid crystal elements are located at the common focal point.

4. The vehicular lamp according to any of claims 1 to 3,

the condensing optical system is a 1 st reflector having a concave elliptical reflecting surface,

the 1 st reflector reflects light from the light source disposed so as to be directed to the 1 st focal point of the elliptical reflecting surface so as to converge toward the 2 nd focal point of the elliptical reflecting surface,

the polarization beam splitter reflects the 2 nd light in such a manner that the condensing point of the 2 nd light is coincident with the rear focal point of the projection optical system.

5. The vehicular lamp according to any of claims 1 to 3,

the condensing optical system is a condensing lens disposed in an optical path between the light source and the polarization beam splitter.

6. The vehicular lamp according to claim 4 or 5,

the reflection optical system is a 2 nd reflector having a hyperbolic reflection surface in a convex shape,

the 2 nd reflector reflects the 1 st light by the hyperbolic reflecting surface so that a condensing point of the 1 st light is coincident with a rear focal point of the projection optical system.

7. The vehicular lamp according to any of claims 1-6,

the polarization rotating element is an 1/2 wave plate.

8. The vehicular lamp according to any of claims 1-7,

the vehicle lamp has a 2 nd polarizing plate, and the 2 nd polarizing plate is disposed in an optical path of the 1 st light and the 2 nd light incident on the liquid crystal cell, and transmits light of a polarization component having a polarization direction out of the 1 st light and the 2 nd light.

9. The vehicular lamp according to any of claims 1-8,

the vehicular lamp includes:

a plurality of light sources; and

a plurality of condensing optical systems provided respectively in correspondence with the plurality of light sources,

the plurality of condensing optical systems condense the light beams emitted from the plurality of light sources, respectively, toward the focal points of points.

Technical Field

The present invention relates to a vehicle lamp.

Background

In recent years, a light distribution variable headlamp (ADB) has been developed which variably controls a light distribution pattern of light projected toward the front of a vehicle. ADB is the following technique: the vehicle-mounted camera recognizes the surrounding situation of the preceding vehicle, the oncoming vehicle, or the like, and blocks light that causes glare to the preceding vehicle or the oncoming vehicle, thereby enlarging the driver's forward field of view at night.

However, , which is a method for realizing such a vehicle lamp, separates light emitted from a light source into two polarization components, and controls and uses the light of each polarization component by a liquid crystal element (for example, see patent documents 1 and 2 listed below).

For example, patent document 1 below discloses the following structure: the light beam emitted from the light source 240 is separated into two polarization components, i.e., a transmitted light 252 and a reflected light 254 by the polarization separation mirror 250, the transmitted light 252 is projected through the liquid crystal element 272, the polarizer 282, and the projection lens 292, and the reflected light 254 is reflected by the reflection mirror 260 and then projected through the liquid crystal element 274, the polarizing plate 284, and the projection lens 294.

, an automotive headlamp 10 is disclosed in the following patent document 2, which comprises a light source 20, a polarization beam splitter 30 for splitting light incident from the light source 20 into two partial light paths S1, S2 polarized in different manners from each other and disposed in the light path of the light source 20, a 1 st liquid crystal mask 40, a 1 st polarization filter 50 and a 1 st lens 60 disposed in the 1 st partial light path S1, and a 2 nd liquid crystal mask 42, a 2 nd polarization filter 52 and a 2 nd lens 62 disposed in the 2 nd partial light path S2, the 1 st lens in the 1 st partial light path S1 having a different focal length f1 from the 2 nd lens 62 in the 2 nd partial light path S2.

Disclosure of Invention

Problems to be solved by the invention

However, in the case where the light emitted from the light source is separated into two polarized light components and the polarized light components are controlled by the liquid crystal element to use the polarized light components, the liquid crystal element and the projection lens corresponding to the polarized light components are required. In this case, the number of parts increases, the structure becomes complicated, and the lamp unit becomes large.

Further, it is impossible to condense the light of two polarization components onto liquid crystal cells simply by increasing the number of light sources, and it is necessary to add both a function of condensing the light from the light sources and a function of making the light of two polarization components incident on the liquid crystal cells.

The present invention has been made in view of the above-described conventional circumstances, and an object thereof is to provide a vehicle lamp which is high in light utilization efficiency and can be further reduced in size by steps by reducing the number of parts and simplifying the structure.

Means for solving the problems

In order to achieve the above object, the present invention provides the following means.

[ 1 ] A vehicle lamp, comprising:

a light source that emits light;

a projection optical system that projects light emitted from the light source toward the front;

a liquid crystal element disposed in alignment with a rear focal point of the projection optical system, the liquid crystal element controlling an image of light projected by the projection optical system;

a 1 st polarizing plate, the 1 st polarizing plate being disposed in an optical path between the liquid crystal element and the projection optical system, and passing light of a specific polarization component therethrough;

a condensing optical system that condenses light emitted from the light source toward the liquid crystal element;

a polarization beam splitter which passes a 1 st light including polarization components among the light emitted from the light source and reflects a 2 nd light including another polarization component to perform separation;

a reflection optical system that reflects the 1 st light toward the liquid crystal element; and

and a polarization rotation element disposed on an optical path between the polarization beam splitter and the liquid crystal element, the polarization rotation element rotating a polarization direction of any of the 1 st light and the 2 nd light to a polarization direction of any other light.

[ 2 ] the vehicular lamp according to the above [ 1 ], wherein,

the 1 st light and the 2 nd light are condensed at a common condensing point with each other.

[ 3 ] the vehicular lamp according to the above [ 2 ], wherein,

the liquid crystal elements are located at the common focal point.

[ 4 ] the vehicular lamp according to any of the above [ 1 ] to [ 3 ], wherein,

the condensing optical system is a 1 st reflector having a concave elliptical reflecting surface,

the 1 st reflector reflects light from the light source disposed so as to be directed to the 1 st focal point of the elliptical reflecting surface so as to converge toward the 2 nd focal point of the elliptical reflecting surface,

the polarization beam splitter reflects the 2 nd light in such a manner that the condensing point of the 2 nd light is coincident with the rear focal point of the projection optical system.

[ 5 ] the vehicular lamp according to any of the above [ 1 ] to [ 3 ], wherein,

the condensing optical system is a condensing lens disposed in an optical path between the light source and the polarization beam splitter.

[ 6 ] the vehicular lamp according to the above [ 4 ] or [ 5 ], wherein,

the reflection optical system is a 2 nd reflector having a hyperbolic reflection surface in a convex shape,

the 2 nd reflector reflects the 1 st light by the hyperbolic reflecting surface so that a condensing point of the 1 st light is coincident with a rear focal point of the projection optical system.

[ 7 ] the vehicular lamp according to any of the above [ 1 ] to [ 6 ], wherein,

the polarization rotating element is an 1/2 wave plate.

[ 8 ] the vehicular lamp according to any of the above [ 1 ] to [ 7 ], wherein,

the vehicle lamp has a 2 nd polarizing plate, and the 2 nd polarizing plate is disposed in an optical path of the 1 st light and the 2 nd light incident on the liquid crystal element, and transmits light of a polarization component having a polarization direction out of the 1 st light and the 2 nd light.

[ 9 ] the vehicular lamp according to any of the above [ 1 ] to [ 8 ], wherein,

the vehicular lamp includes:

a plurality of light sources; and

a plurality of condensing optical systems provided respectively in correspondence with the plurality of light sources,

the plurality of condensing optical systems condense the light beams emitted from the plurality of light sources, respectively, toward the focal points of points.

Effects of the invention

As described above, according to the present invention, it is possible to provide a vehicle lamp which is high in light utilization efficiency and can be further reduced in size by steps by reducing the number of parts and simplifying the structure.

Drawings

Fig. 1 is a perspective view of a lamp unit included in a vehicle lamp according to embodiment 1 of the present invention, as viewed from the front.

Fig. 2 is a perspective view of the lamp unit shown in fig. 1, as viewed from the back side.

Fig. 3 is a perspective view of the lamp unit shown in fig. 1, as viewed from the back side, with the reflector unit removed.

Fig. 4 is a sectional view showing the structure of the lamp unit shown in fig. 1.

Fig. 5 is a schematic diagram illustrating a light path of light in the lamp unit shown in fig. 1.

Fig. 6 is a perspective view of a lamp unit included in the vehicle lamp according to embodiment 2 of the present invention, as viewed from the front.

Fig. 7 is a perspective view of the lamp unit shown in fig. 6, as viewed from the back side.

Fig. 8 is a front view showing the structure of the lamp unit shown in fig. 6.

Fig. 9 is a rear view showing the structure of the lamp unit shown in fig. 6.

Fig. 10 is a side view showing the structure of the lamp unit shown in fig. 6.

Fig. 11 is a schematic diagram showing an optical path of light in the lamp unit shown in fig. 6.

Fig. 12 is a schematic diagram showing a configuration of a lamp unit included in the vehicle lamp according to embodiment 3 of the present invention and an optical path of light thereof.

Description of the symbols

1A to 1C … vehicle lamps 2A to 2C … lamp unit 3 … light source 4 … projection lens (projection optical system) 5 … liquid crystal element 6 … first reflector (condensing optical system) 6a … elliptical reflecting surface 7 … polarization beam splitter 8 … second reflector (reflection optical system) 8a … hyperbolic reflecting surface 9 … polarization rotating element (1/2 wave plate) 10 … first polarizing plate 11 … second polarizing plate 12 … mounting substrate 13 … heat sink 14 … cooling fan 15 … holding frame 16, 17 … reflector unit 18 … condenser lens (condensing optical system) L … light L1 … first light L2 … second light.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In the drawings shown below, an XYZ rectangular coordinate system is set, and an X axis direction is a front-back direction (longitudinal direction) of the vehicle lamp, a Y axis direction is a left-right direction (width direction) of the vehicle lamp, and a Z axis direction is a vertical direction (height direction) of the vehicle lamp.

(embodiment 1)

First, as embodiment 1 of the present invention, a vehicle lamp 1A shown in fig. 1 to 5, for example, will be described.

Fig. 1 is a perspective view of a lamp unit 2A included in a vehicle lamp 1A, as viewed from the front. Fig. 2 is a perspective view of the lamp unit 2A as viewed from the back side. Fig. 3 is a perspective view of the lamp unit 2A from the back side with the reflector unit 16 removed. Fig. 4 is a sectional view showing the structure of the lamp unit 2A. Fig. 5 is a schematic diagram showing the optical path of light in the lamp unit 2A.

The vehicle lamp 1A of the present embodiment is applied to a light distribution variable headlamp (ADB) that variably controls a light distribution pattern of light projected forward of a vehicle, as a vehicle headlamp (headlamp) mounted forward of the vehicle, for example.

Specifically, the vehicle lamp 1A includes a lamp unit 2A. The vehicle lamp 1A has a configuration in which the lamp unit 2A is disposed inside a lamp body including a housing whose front surface is open, and a transparent lens cover covering the opening of the housing, which are not shown.

The lamp unit 2A of the present embodiment includes a light source 3, a projection optical system 4, a liquid crystal element 5, a condensing optical system 6, a polarization beam splitter 7, a reflection optical system 8, a polarization rotation element 9, a 1 st polarizing plate 10, and a 2 nd polarizing plate 11.

The light source 3 emits unpolarized (unpolarized) light L, and in the present embodiment, a light emitting element such as a Light Emitting Diode (LED) that emits white light is used as the light source 3, and a high-output (high-luminance) type LED for vehicle illumination is used as the LED the light source 3 radially emits the light L emitted from the LED toward the rear side (-X axis direction) in a state where the LED is mounted on the surface (rear surface in the present embodiment) of the mounting substrate 12.

The light source 3 may be a light emitting element such as a Laser Diode (LD) in addition to the LED described above, and a light source other than the light emitting element described above may be used.

The mounting board 12 is constituted by a rectangular printed wiring board having at least sides provided with wiring (not shown) electrically connected to the above-described LEDs (light sources 3), and when the light sources 3 are constituted by a plurality of LEDs, these plurality of LEDs are mounted in a state of being arranged at equal intervals in the width direction of the mounting board 12.

Although not shown, in the lamp unit 2A of the present embodiment, the mounting board 12 on which the above-described LED (light source 3) is mounted and a circuit board on which an LED driving circuit for driving the LED (light source 3) is provided are disposed separately, and these mounting board and circuit board are electrically connected to each other via a wiring cord called a harness (harness). Thus, the LED driving circuit is protected from being damaged by heat emitted from the LED (light source 3).

Further, the lamp unit 2A of the present embodiment includes: a heat sink 13 having a plurality of heat radiating fins 13a provided on a front surface side thereof for radiating heat emitted from the light source 3; and a cooling fan 14 disposed on the front surface side of the heat sink 13.

The mounting substrate 12 is mounted on the rear surface side of the heat sink 13 at a position facing the heat radiating fins 13a by screwing or the like. The mounting board 12 may be mounted on the heat sink 13 via a heat conductive member such as a heat conductive grease.

The heat sink 13 is configured by using a metal material such as aluminum or copper having high thermal conductivity, a resin material, or a composite material thereof for at least in part or all, and the cooling fan 14 blows air toward the heat radiation fins 13a, thereby efficiently radiating heat transferred from the light source 3 side to the heat sink 13 side to the outside.

The projection optical system 4 is configured by at least or a plurality of ( in the present embodiment) lenses (hereinafter referred to as projection lenses 4) that project the light L emitted from the light source 3 forward (+ X-axis direction), the projection lenses 4 are disposed at positions on the front side of the liquid crystal element 5 in a state of being held by the holder 15, the holder 15 is attached to the heat sink 13 at a position above the heat sink 13a on the front surface side by screwing or the like, and the heat sink 13 is provided with a cutout portion 13b that is cut out so as to face the projection lenses 4, in another .

The liquid crystal element 5 is constituted by a transmissive liquid crystal panel (LCD). The liquid crystal element 5 is disposed so as to be aligned with the rear focal point fp of the projection lens 4. That is, the liquid crystal element 5 is located at or near the rear focal point fp of the projection lens 4. In the lamp unit 2A of the present embodiment, the liquid crystal element 5 is held inside the holder 15.

The liquid crystal element 5 controls a driving voltage applied between the electrodes by a liquid crystal driving circuit (not shown) to modulate light (1 st light L1 and 2 nd light L2 described later) passing through the liquid crystal element 5 and control an image (light distribution pattern) of the light L1 and the light L2 projected by the projection lens 4.

The liquid crystal element 5 may be of a segment type in which modulation of light is switched by controlling a drive voltage applied between electrodes for segments, or may be of a dot matrix type in which modulation of light is switched in an arbitrary region by controlling a drive voltage applied between electrodes at each dot (pixel) arranged in a matrix.

The condensing optical system 6 is constituted by a 1 st reflector (hereinafter referred to as a 1 st reflector 6) for condensing the light L emitted from the light source 3 toward the liquid crystal element 5. the 1 st reflector 6 has a concave elliptical reflecting surface 6a formed so that an elliptical line having two focal points fe1, fe2 is drawn in a cross-sectional shape thereof. the 1 st focal point fe1 of the elliptical reflecting surface 6a is aligned with the light source 3 . thus, the 1 st reflector 6 reflects the light L from the light source 3 disposed so as to be aligned with the 1 st focal point fe1 of the elliptical reflecting surface 6a, and condenses the light L toward the 2 nd focal point fe2 of the elliptical reflecting surface 6 a.

The polarization beam splitter 7 splits the light L emitted from the light source 3 into a 1 st light L1 containing polarization components (for example, P-polarization components) and a 2 nd light L2 containing another polarization components (for example, S-polarization components). the polarization beam splitter 7 is disposed on an optical path between the condensing optical system (1 st reflector) 6 and the reflecting optical system (2 nd reflector described later) 8.

As the polarization beam splitter 7, for example, a wire grid system, a system using an optical multilayer film, or the like can be used. The polarizing beam splitter 7 is not limited to a flat plate type, and may be a cube type in which two right-angle prisms are combined.

The polarization beam splitter 7 passes the 1 st light L1 of the light L emitted from the light source 3 upward (+ Z-axis direction) and reflects the 2 nd light L2 forward (+ X-axis direction), and the polarization beam splitter 7 reflects the 2 nd light L2 so that the condensing point C2 of the 2 nd light L2 coincides with the rear side focal point fp of the projection lens 4.

The reflection optical system 8 is constituted by a 2 nd reflector (hereinafter, referred to as the 2 nd reflector 8) that reflects the 1 st light L1 toward the liquid crystal element 5, the 2 nd reflector 8 has a convex hyperbolic reflection surface 8a formed so as to draw a hyperbolic curve having two focuses fh1 and fh2 in a cross-sectional shape, the hyperbolic reflection surface 8a has its 1 st focus fh1 aligned with the 2 nd focus fe2 of the elliptic reflection surface 6a and its 2 nd focus fh2 aligned with the rear side focus fp of the projection lens 4, and thereby the 2 nd reflector 8 reflects the 1 st light L1 by the hyperbolic reflection surface 8a so that the focal point C1 of the 1 st light L1 is aligned with the rear side focus fp of the projection lens 4.

Here, the lamp unit 2A of the present embodiment includes the reflector unit 16 constituted by the above-described 1 st reflector 6 and 2 nd reflector 8 , the reflector unit 16 is made of, for example, a resin material, and the elliptical reflecting surface 6a and the hyperbolic reflecting surface 8a are made of, for example, a metal reflecting film formed by vapor deposition of, for example, an aluminum alloy or the like having a high reflectance in .

In the lamp unit 2A of the present embodiment, the reflector unit 16 is attached to the rear surface side of the heat sink 13 by screwing or the like in a state where the polarization beam splitter 7 is held inside the reflector unit 16.

The polarization rotation element 9 is constituted by an 1/2 wave plate (λ/2) arranged in the optical path between the polarization beam splitter 7 and the liquid crystal element 5. The lamp unit 2A of the present embodiment is attached to the front surface side of the reflector unit 16.

The polarization rotator 9 passes through the liquid crystal element 5 in a state where the polarization direction of any light (in this embodiment, 1 st light L1) of the 1 st light L1 and the 2 nd light L2 is rotated so as to coincide with the polarization direction of any other light (in this embodiment, 2 nd light L2).

Therefore, in the present embodiment, the λ/2 plate (polarization rotating element 9) is disposed on the optical path between the 2 nd reflector 8 and the liquid crystal element 5 of the 1 st light L1. The λ/2 plate converts the polarization direction of the 1 st light L1 from P polarization to S polarization. This makes it possible to align the polarization directions of the 1 st light L1 and the 2 nd light L2.

On the other hand, in , when the polarization direction of the 2 nd light L2 is rotated to match the polarization direction of the 1 st light L1, a λ/2 plate (polarization rotation element 9) may be disposed on the optical path between the polarization beam splitter 7 of the 2 nd light L2 and the liquid crystal element 5, and in this case, the polarization direction of the 2 nd light L2 can be converted from S polarization to P polarization by the λ/2 plate, and the polarization directions of the 1 st light L1 and the 2 nd light L2 can be aligned.

As the polarization rotator 9, in addition to the retardation plate such as the λ/2 plate described above, an optical element that rotates the polarization direction, such as a faraday element or a liquid crystal element, can be used.

The 1 st polarizing plate 10 is disposed in the optical path between the liquid crystal element 5 and the projection lens 4. In the lamp unit 2A of the present embodiment, the 1 st polarizing plate 10 is held inside the holder 15.

The 1 st polarizing plate 10 transmits light having a specific polarization component of the 1 st light L1 and the 2 nd light L2 modulated by the liquid crystal cell 5. That is, the 1 st polarizing plate 10 transmits light having a polarization component corresponding to the light distribution pattern of the light controlled by the liquid crystal cell 5, and cuts light having other polarization components. Thus, the 1 st light L1 and the 2 nd light L2 modulated by the liquid crystal element 5 can be selectively passed through in accordance with the light distribution pattern of the light controlled by the liquid crystal element 5.

The 2 nd polarizing plate 11 is disposed in the optical path of the 1 st light L1 and the 2 nd light L2 incident on the liquid crystal cell 5. In the lamp unit 2A of the present embodiment, the 2 nd polarizing plate 11 is held inside the holder 15.

The 2 nd polarizing plate 11 passes light having a polarization component (S polarization in the present embodiment) in the polarization direction of the 1 st light L1 and the 2 nd light L2, and cuts off light having other polarization components, thereby increasing the degree of polarization of the 1 st light L1 and the 2 nd light L2 entering the liquid crystal cell 5, and as a result, increasing the contrast of the light distribution pattern of light controlled by the liquid crystal cell 5.

In the lamp unit 2A of the present embodiment, the polarization directions of the 1 st light L1 and the 2 nd light L2 incident on the liquid crystal cell 5 can be aligned by the polarization rotator 9, and therefore the 2 nd polarizing plate 11 can be omitted as appropriate.

The first polarizing plate 10 and the second polarizing plate 11 described above are preferably disposed apart from the liquid crystal elements 5, because they generate heat by blocking (absorbing) light.

In the vehicle lamp 1A of the present embodiment having the above configuration, the surrounding information of the preceding vehicle, the oncoming vehicle, and the like is determined by the control circuit unit, not shown, using the image obtained from the camera provided in the vehicle or the information of various sensors provided in the vehicle, the area to be blocked is calculated, and the information of the area to be blocked is transmitted to the liquid crystal driving circuit as a control signal.

The liquid crystal driving circuit controls the driving of the liquid crystal element 5 in accordance with a control signal from the control circuit unit, and controls the images (light distribution patterns) of the light beams L1 and L2 projected by the projection lens 4. This makes it possible to variably control the light distribution pattern of the light beams L1 and L2 projected from the projection lens 4 toward the front of the vehicle.

That is, the vehicle lamp 1A of the present embodiment is configured to recognize the surrounding situation of the preceding vehicle, the oncoming vehicle, or the like by the in-vehicle camera or the like as the ADB, and to block the light that causes glare to the preceding vehicle or the oncoming vehicle, thereby making it possible to increase the forward field of view of the driver at night.

In the lamp unit 2A of the present embodiment, the light L emitted from the light source 3 is reflected while being condensed toward the liquid crystal element 5 by the 1 st reflector 6 (elliptical reflection surface 6a), and the light L emitted from the light source 3 is separated into the 1 st light L1 including polarization components passing through the polarization beam splitter 7 and the 2 nd light L2 including another polarization component reflected by the polarization beam splitter 7.

Here, the 1 st light L1 is reflected toward the liquid crystal cell 5 by the 2 nd reflector 8 (hyperbolic reflective surface 8a) and, on the other hand, , the 2 nd light L2 is reflected toward the liquid crystal cell 5 by the polarizing beam splitter 7, and the 1 st light L1 and the 2 nd light L2 enter the liquid crystal cell 5 in a (aligned) state in which the polarization directions of each other are changed to by the polarization rotating element 9 and the 2 nd polarizing plate 11.

Here, the 1 st reflector 6 condenses and reflects the light L from the light source 3 disposed so as to be aligned with the 1 st focal point fe1 of the elliptical reflecting surface 6a toward the 2 nd focal point fe2 of the elliptical reflecting surface 6a, and the 2 nd reflector 8 condenses and reflects the 1 st light L1 toward the 2 nd focal point fh2 of the hyperbolic reflecting surface 8a by aligning the 1 st focal point fh1 of the hyperbolic reflecting surface 8a with the 2 nd focal point fe2 of the elliptical reflecting surface 6a and aligning the 2 nd focal point fh2 of the hyperbolic reflecting surface 8a with the rear side focal point fp of the projection lens 4, in addition to .

Thus, the 2 nd reflector 8 reflects the 1 st light L1 so that the focal point C1 of the 1 st light L1 coincides with the rear side focal point fp of the projection lens 4, and the polarization beam splitter 7 reflects the 2 nd light L2 so that the focal point C2 of the 2 nd light L2 coincides with the rear side focal point fp of the projection lens 4 in .

Therefore, in the lamp unit 2A of the present embodiment, the 1 st light L1 and the 2 nd light L2 are condensed at the common condensing points C1 and C2 (the rear focal point fp of the projection lens 4), and thus, the light of two polarization components (the 1 st light L1 and the 2 nd light L2) separated by the polarization beam splitter 7 can be condensed with respect to the liquid crystal elements 5 without increasing the number of light sources 3, and the utilization efficiency of the light L emitted from the light sources 3 can be improved.

In the lamp unit 2A of the present embodiment, the liquid crystal element 5 is located at the common focal points C1 and C2 (the rear focal point fp of the projection lens 4), and thus, the polarization directions of the 1 st light L1 and the 2 nd light L2 incident on the liquid crystal element 5 can be further -dependent (aligned) in a state, and as a result, the influence of the viewing angle dependency of the liquid crystal element 5 can be reduced, and the amounts of light L1 and L2 incident on the projection lens 4 through the liquid crystal element 5 can be increased.

Therefore, in the lamp unit 2A of the present embodiment, the luminance of the light distribution pattern of the light beams L1 and L2 projected forward of the vehicle from the projection lens 4 can be increased, and as a result, the visibility in front of the vehicle (particularly, at a distance) can be improved, and the safety can be further improved .

In the lamp unit 2A of the present embodiment, it is not necessary to prepare the liquid crystal element 5, the projection lens 4, and the like for each of the two polarized components of light separated by the polarization beam splitter 7, and these elements can be used in common, whereby the number of parts constituting the lamp unit 2A can be reduced and the structure can be simplified, and further -step reduction and weight reduction of the lamp unit 2A can be achieved.

As described above, in the vehicle lamp 1A of the present embodiment, by providing the lamp unit 2A as described above, it is possible to improve the utilization efficiency of the light emitted from the light source 3, and to reduce the number of parts and simplify the structure, thereby realizing further steps of downsizing and weight saving of the lamp unit 2A.

(embodiment 2)

Next, as embodiment 2 of the present invention, a vehicle lamp 1B shown in fig. 6 to 11, for example, will be described.

Fig. 6 is a perspective view of the lamp unit 2B of the vehicle lamp 1B as viewed from the front. Fig. 7 is a perspective view of the lamp unit 2B as viewed from the back side. Fig. 8 is a front view showing the structure of the lamp unit 2B. Fig. 9 is a rear view showing the structure of the lamp unit 2B. Fig. 10 is a side view showing the structure of the lamp unit 2B. Fig. 11 is a schematic diagram showing the optical path of light in the lamp unit 2B. In the following description, the same portions as those of the vehicle lamp 1A (lamp unit 2A) are not described, and the same reference numerals are given to the drawings.

The vehicle lamp 1B of the present embodiment includes a lamp unit 2B. The vehicle lamp 1B has a structure in which the lamp unit 2B is disposed inside a lamp body including a case whose front surface is open, and a transparent lens cover covering the opening of the case, which are not shown.

The lamp unit 2B of the present embodiment includes: a plurality of (two in the present embodiment) light sources 3; and a plurality of (two in the present embodiment) 1 st reflectors 6 provided corresponding to the plurality of light sources 3, respectively.

The lamp unit 2B of the present embodiment includes a projection lens (projection optical system) 4, a liquid crystal element 5, a polarization rotation element 9, a 1 st polarizing plate 10, and a 2 nd polarizing plate 11, in the same manner as the lamp unit 2A, except that the reflector unit 17 is integrally configured by the plurality of 1 st reflectors 6, the polarization beam splitter 7, and the 2 nd reflector 8 .

In the lamp unit 2B, a plurality of (two in the present embodiment) mounting boards 12 on which the light sources 3 are mounted on the rear surface side of the heat sink 13 (not shown in fig. 6 to 11) by screwing or the like.

The plurality of 1 st reflectors 6 reflect the light L from each light source 3 arranged so as to be aligned with the 1 st focal point fe1 of each elliptical reflecting surface 6a while condensing it toward the 2 nd focal point fe2 of each elliptical reflecting surface 6a, and the 2 nd focal points fe2 of the elliptical reflecting surfaces 6a of the 1 st reflectors 6 are located at positions from each other, and therefore, the plurality of 1 st reflectors 6 condense the light L emitted from each of the plurality of light sources 3 toward the focal point from each other (the 2 nd focal point fe 2).

Further , the 2 nd reflector 8 focuses the 1 st light L1 toward the 2 nd focal point fh2 of the hyperbolic reflective surface 8a and reflects the 1 st light L1 simultaneously by focusing the 1 st focal point fh1 of the hyperbolic reflective surface 8a and the common 2 nd focal point fe2 of the elliptic reflective surface 6a of each 1 st reflector 6 and focusing the 2 nd focal point fh2 of the hyperbolic reflective surface 8a and the rear focal point fp of the projection lens 4.

Thus, the 2 nd reflector 8 reflects the 1 st light L1 so that the focal point C1 of the 1 st light L1 coincides with the rear side focal point fp of the projection lens 4, and the polarizing beam splitter 7 reflects the 2 nd light L2 so that the focal point C2 of the 2 nd light L2 coincides with the rear side focal point fp of the projection lens 4 in the other .

Therefore, in the lamp unit 2B of the present embodiment, the 1 st light L1 and the 2 nd light L2 separated by the polarization beam splitter 7 among the light L emitted from the plurality of light sources 3 described above are condensed at the common condensing points C1 and C2 (the rear focal point fp of the projection lens 4), and thus, even when the number of light sources 3 is increased, the light of two polarization components separated by the polarization beam splitter 7 (the 1 st light L1 and the 2 nd light L2) can be condensed with respect to the liquid crystal elements 5, and the utilization efficiency of the light L emitted from the plurality of light sources 3 can be improved.

In the lamp unit 2B of the present embodiment, the liquid crystal element 5 is located at the common focal points C1 and C2 (the rear focal point fp of the projection lens 4), and thus the polarization directions of the 1 st light L1 and the 2 nd light L2 incident on the liquid crystal element 5 can be further -dependent (aligned) in a state, and as a result, the influence of the viewing angle dependency of the liquid crystal element 5 can be reduced, and the amounts of light L1 and L2 incident on the projection lens 4 through the liquid crystal element 5 can be increased.

Therefore, in the lamp unit 2B of the present embodiment, even when a plurality of light sources 3 are used, the luminance of the light distribution pattern of the light beams L1 and L2 projected forward of the vehicle from the projection lens 4 can be increased, and as a result, the visibility in front of the vehicle (particularly, at a distance) can be increased, and the safety can be further improved .

In the lamp unit 2B of the present embodiment, when the plurality of light sources 3 are used, the polarizing beam splitter 7, the 2 nd reflector 8, the liquid crystal element 5, the projection lens 4, and other elements can be used in common, and thus, even when the plurality of light sources 3 are used, the number of parts constituting the lamp unit 2B can be reduced and the structure can be simplified, and further, the size and weight of the lamp unit 2B can be reduced by steps.

As described above, in the vehicle lamp 1B according to the present embodiment, by providing the lamp unit 2B described above, it is possible to improve the utilization efficiency of the light emitted from the plurality of light sources 3, and to reduce the number of parts and simplify the structure, thereby making it possible to further -step reduce the size and weight of the lamp unit 2B.

(embodiment 3)

Next, as embodiment 3 of the present invention, a vehicle lamp 1C shown in fig. 12, for example, will be described. Fig. 12 is a schematic diagram showing the configuration of a lamp unit 2C included in the vehicle lamp 1C and the optical path of light thereof. In the following description, the same portions as those of the vehicle lamp 1A (lamp unit 2A) are not described, and the same reference numerals are given to the drawings.

The vehicle lamp 1C of the present embodiment includes a lamp unit 2C. The vehicle lamp 1C has a structure in which the lamp unit 2C is disposed inside a lamp body including a case whose front surface is open, and a transparent lens cover covering the opening of the case, which are not shown.

The lamp unit 2C of the present embodiment has a condenser lens 18 as a condensing optical system in place of the 1 st reflector 6, the condenser lens 18 is configured by at least or a plurality of lenses ( in the present embodiment) for condensing the light L emitted from the light source 3 toward the liquid crystal device 5, the condenser lens 18 is disposed on the optical path between the light source 3 and the polarization beam splitter 7, and other than that, the lamp unit 2C has basically the same configuration as the lamp unit 2A.

In the lamp unit 2C of the present embodiment having the above configuration, the light L emitted from the light source 3 is condensed by the condenser lens 18 toward the liquid crystal element 5, and the light L emitted from the light source 3 is separated into the 1 st light L1 containing polarization components passing through the polarization beam splitter 7 and the 2 nd light L2 containing another polarization component reflected by the polarization beam splitter 7.

Here, the 1 st light L1 is reflected toward the liquid crystal element 5 by the 2 nd reflector 8 (hyperbolic reflective surface 8a) and, on the other hand, , the 2 nd light L2 is reflected toward the liquid crystal element 5 by the polarizing beam splitter 7, and the 1 st light L1 and the 2 nd light L2 enter the liquid crystal element 5 in a (aligned) state where the polarization directions of each other are changed to by the polarization rotation element 9 and the 2 nd polarizing plate 11.

Here, the condenser lens 18 condenses the light L emitted from the light source 3 to the front side focal point fc, and , the 2 nd reflector 8 condenses the 1 st focal point fh1 of the hyperbolic reflective surface 8a to the front side focal point fc of the condenser lens 18, and condenses the 2 nd focal point fh2 of the hyperbolic reflective surface 8a to the rear side focal point fp of the projection lens 4, thereby reflecting the 1 st light L1 while condensing it to the 2 nd focal point fh2 of the hyperbolic reflective surface 8 a.

Thus, the 2 nd reflector 8 reflects the 1 st light L1 so that the focal point C1 of the 1 st light L1 coincides with the rear side focal point fp of the projection lens 4, and the polarizing beam splitter 7 reflects the 2 nd light L2 so that the focal point C2 of the 2 nd light L2 coincides with the rear side focal point fp of the projection lens 4 in the other .

Therefore, in the lamp unit 2C of the present embodiment, the 1 st light L1 and the 2 nd light L2 are condensed at the common condensing points C1 and C2 (the rear focal point fp of the projection lens 4), and thus, the light of two polarization components (the 1 st light L1 and the 2 nd light L2) separated by the polarization beam splitter 7 can be condensed with respect to the liquid crystal elements 5 without increasing the number of light sources 3, and the utilization efficiency of the light L emitted from the light sources 3 can be improved.

In the lamp unit 2C of the present embodiment, the liquid crystal element 5 is located at the common focal points C1 and C2 (the rear focal point fp of the projection lens 4), and thus, the polarization directions of the 1 st light L1 and the 2 nd light L2 incident on the liquid crystal element 5 can be further -dependent (aligned) in a state, and as a result, the influence of the viewing angle dependency of the liquid crystal element 5 can be reduced, and the amounts of light L1 and L2 incident on the projection lens 4 through the liquid crystal element 5 can be increased.

Therefore, in the lamp unit 2C of the present embodiment, the luminance of the light distribution pattern of the light beams L1 and L2 projected forward of the vehicle from the projection lens 4 can be increased, and as a result, the visibility in front of the vehicle (particularly, at a distance) can be improved, and the safety can be further improved .

Further, in the lamp unit 2C of the present embodiment, it is not necessary to prepare the liquid crystal element 5, the projection lens 4, and the like for each of the two polarized components separated by the polarization beam splitter 7, and these elements can be used in a common use, whereby the number of parts constituting the lamp unit 2C can be reduced and the structure can be simplified, and further, -step reduction and weight reduction of the lamp unit 2C can be achieved.

As described above, in the vehicle lamp 1C of the present embodiment, by providing the lamp unit 2C described above, it is possible to improve the utilization efficiency of the light emitted from the light source 3, and to reduce the number of parts and simplify the structure, thereby making it possible to further reduce the size and weight of the lamp unit 2C by steps.

The present invention is not necessarily limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention.

For example, although the polarization beam splitter 7 is held inside the reflector units 16 and 17 integrally configured by the 1 st reflector 6 and the 2 nd reflector 8 described above in the above embodiment, a light guide unit integrally configured by the 1 st reflector 6 (elliptical reflecting surface 6a), the 2 nd reflector 8 (hyperbolic reflecting surface 8a), and the polarization beam splitter 7 may be used.

Specifically, the light guide unit has a configuration in which the polarization beam splitter 7 is disposed on the abutting surface of the light guide, and the elliptical reflecting surface 6a and the hyperbolic reflecting surface 8a are disposed on the outer peripheral surface of the light guide. In the light guide unit, light L emitted from the light source 3 is guided inside the light guide body, and light of two polarization components (1 st light L1 and 2 nd light L2) separated by the polarization beam splitter 7 is reflected by the elliptical reflection surface 6a and the hyperbolic reflection surface 8 a. This makes it possible to obtain the same configuration as the 1 st reflector 6 (elliptical reflecting surface 6a), the 2 nd reflector 8 (hyperbolic reflecting surface 8a), and the polarization beam splitter 7 described above.

In the above-described embodiment, the present invention is applied to the light distribution variable headlamp (ADB) described above, but in addition to this, the present invention can be applied to a light distribution variable headlamp System (AFS: Adaptive Front-lighting System) that controls a liquid crystal element in accordance with a steering angle (turning angle) or a speed (vehicle speed) of a vehicle that is turning and traveling, and that enlarges an irradiation range of a headlight short-focus lamp in a traveling direction of the vehicle, thereby ensuring visibility in the traveling direction of the vehicle.

Further, the present invention can be applied to a dual-function (Bi-function) type vehicle lamp in which a light distribution pattern for a headlight including a cutoff line at an upper end thereof as a headlight short-focus lamp (low beam) and a light distribution pattern for a high beam positioned above the light distribution pattern for the headlight short-focus lamp as a traveling light beam (hi beam) are switched by lamp units.