JP2023164961A - Vehicular lighting fixture - Google Patents

Abstract

To provide a vehicular lighting fixture in which a width of each incidence spot in a horizontal direction can be reduced in comparison with a case where a specific direction and the horizontal direction are made parallel, and a width of each phase modulation element in the horizontal direction can be reduced in comparison with the case where the specific direction and the horizontal direction are made parallel.SOLUTION: A vehicular lighting fixture comprises light sources, and a phase modulation element assembly 54 including phase modulation elements 54R, 54G, and 54B having a plurality of modulation parts MPR, MPG, and MPB for shaping light from the light sources into a predetermined pattern by diffracting the light. Incidence surfaces of the phase modulation elements 54R, 54G, and 54B are formed in an approximately rectangular shape that is long in a lateral direction, and incidence spots SR, SG, and SB of the light in the phase modulation elements 54R, 54G, and 54B are formed in an approximately elliptical shape that is long in the lateral direction.SELECTED DRAWING: Figure 9

Description

The present invention relates to a vehicle lamp.

2. Description of the Related Art Various configurations have been considered for vehicle lamps, such as automobile headlights, in order to achieve a predetermined light distribution pattern of emitted light. For example, Patent Document 1 below describes forming a predetermined light distribution pattern using a hologram element, which is a type of phase modulation element.

The vehicle lamp described in Patent Document 1 below includes a hologram element and a light source that irradiates the hologram element with reference light. The hologram element is calculated so that the diffracted light reproduced by being irradiated with the reference light forms a predetermined light distribution pattern. Further, the shape of this hologram element is generally rectangular.

Japanese Patent Application Publication No. 2012-146621

A vehicular lamp according to a first aspect of the present invention includes a phase modulation element having a light source that emits light and a plurality of modulation units that diffracts the light from the light source to form a predetermined light distribution pattern. The width of the light incident surface in the vertical direction of the phase modulating element is larger than the horizontal width of the incident surface, and the size of the light incident spot on the phase modulating element is , is characterized in that it is sized to include at least one of the modulation sections, and at least some of the plurality of modulation sections are arranged in parallel in the vertical direction.

The vertical amplitude of vehicle vibration tends to be larger than the horizontal amplitude, and vehicle lamps also vibrate in the same way as the vehicle. Therefore, the incident spot of light on the phase modulation element tends to vibrate in the vertical direction rather than in the horizontal direction. In this vehicle lamp, as described above, the width of the light incident surface of the phase modulation element in the vertical direction is larger than the width of the light incident surface in the horizontal direction. Therefore, even if the incident spot vibrates in the vertical direction in response to vehicle vibration, this vehicle lamp can prevent part of the incident spot from protruding from the incident surface of the phase modulation element, reducing energy efficiency. can be restrained from doing so. Further, in this vehicle lamp, as described above, the size of the incident spot is large enough to include at least one modulation section, and at least some of the plurality of modulation sections are arranged in parallel in the vertical direction. . Therefore, in this vehicular lamp, even when the incident spot vibrates in the vertical direction in response to vibrations of the vehicle, light can enter any of the modulation sections, so that a predetermined light distribution pattern can be formed.

The incident spot may have a longer shape in a specific direction than in other directions, and the specific direction and the horizontal direction may be non-parallel.

With such a configuration, the width of the incident spot in the horizontal direction can be made smaller than when the specific direction and the horizontal direction are parallel. Therefore, compared to the case where the specific direction and the horizontal direction are parallel, the width of the phase modulation element in the horizontal direction can be made smaller, and the manufacturing cost of the vehicle lamp can be reduced.

Alternatively, the incident spot may have a longer shape in a specific direction than in other directions, and the specific direction and the vertical direction may be non-parallel.

With such a configuration, the width of the incident spot in the vertical direction can be made smaller than when the specific direction and the vertical direction are parallel. Therefore, compared to the case where a specific direction and the vertical direction are parallel, when the incident spot vibrates in the vertical direction in response to vehicle vibration, a part of this incident spot protrudes from the incident surface of the phase modulation element. can be suppressed.

The plurality of modulation units may be arranged in parallel in the vertical direction and in the horizontal direction, and the number of the modulation units arranged in parallel in the vertical direction may be greater than the number of modulation units arranged in parallel in the horizontal direction. good.

With this configuration, the incident spot can be moved vertically in response to vehicle vibrations, compared to a case where the number of modulation units arranged in parallel in the vertical direction is smaller than the number of modulation units arranged in parallel in the horizontal direction. When vibrating, it is possible to make it easier for light from the light source to enter one of the modulation sections.

The vehicle lamp has a plurality of light sources, the phase modulation element is provided for each of the plurality of light sources, and the phase modulation element maximizes the optical path length with the corresponding light source among the plurality of phase modulation elements. The width of the incident spot in the element in the vertical direction may be less than or equal to the maximum width of the incident spots in the other phase modulation elements in the vertical direction.

The amplitude of vibration of the incident spot relative to the phase modulation element tends to increase as the optical path length between the phase modulation element and the light source becomes longer. In this vehicle lamp, the vertical width of the incident spot on the phase modulating element, where the amplitude of vibration of the incident spot with respect to the phase modulating element tends to be large, is the largest of the vertical widths of the incident spots on the other phase modulating elements. It is considered to be less than or equal to the width. Therefore, even without adjusting the vertical width of the incident surface of the phase modulation element or the optical path length between the phase modulation element and the light source, the amplitude of vibration of the incident spot with respect to the phase modulation element tends to increase. Part of the spot can be prevented from protruding from the incident surface of the phase modulation element. Therefore, the degree of freedom in the size of the phase modulation element and the arrangement of the phase modulation element with respect to the light source can be improved.

A plurality of the light sources are provided, the phase modulation element is provided for each of the plurality of light sources, and at least one of the phase modulation elements is connected to at least one other phase modulation element so as to be connected to the other phase modulation element. It may also be formed integrally.

In this vehicle lamp, at least two phase modulating elements are integrally formed, so the number of parts can be reduced.

A vehicular lamp according to a second aspect of the present invention includes a light source that emits light, and a phase modulation unit that includes at least one modulation unit that diffracts the light from the light source to make the light into a predetermined light distribution pattern. an incident surface of the phase modulating element on which the light enters, and an incident spot of the light on the phase modulating element having a longer shape in a predetermined direction than in other directions, and The size of the spot is large enough to include at least one of the modulation sections, and the longitudinal direction of the incident surface of the phase modulation element and the longitudinal direction of the incident spot are non-perpendicular. do.

In this vehicle lamp, the light from the light source can be incident on at least one modulation section, so that a predetermined light distribution pattern can be formed by the modulation section into which the light is incident. Further, in this vehicle lamp, as described above, the longitudinal direction of the incident surface of the phase modulation element is not perpendicular to the longitudinal direction of the incident spot. Therefore, compared to the case where the longitudinal direction of the incident surface of the phase modulation element is perpendicular to the longitudinal direction of the incident spot, this vehicle lamp can be used to change the incident spot without adjusting the shape of the light from the light source. Part of it can be prevented from protruding from the phase modulation element. Therefore, the vehicular lamp can suppress increase in size while suppressing a decrease in energy efficiency.

Further, in the vehicle lamp according to the second aspect, the longitudinal direction of the incident surface of the phase modulation element and the longitudinal direction of the incident spot may be parallel to each other.

With such a configuration, it is possible to further suppress part of the incident spot from protruding from the phase modulation element without adjusting the shape of the laser beam.

Further, in the vehicle lamp according to the second aspect, the longitudinal direction of the incident surface of the phase modulating element may be a horizontal direction.

Further, the vehicle lamp according to the second aspect includes a plurality of the light sources, the phase modulation element is provided for each of the plurality of light sources, and at least one of the phase modulation elements It may be connected to the element and formed integrally with the other phase modulation element.

In this vehicle lamp, at least two phase modulating elements are integrally formed, so the number of parts can be reduced.

Further, the vehicle lamp according to the second aspect includes a plurality of the light sources, the phase modulation element is provided for each of the plurality of light sources, and at least two of the phase modulation elements are arranged in parallel adjacent to each other in a specific direction. The longitudinal direction of each of the incident surfaces of the at least two phase modulating elements may be parallel to the specific direction.

In this vehicle lamp, as described above, at least two phase modulation elements are arranged in parallel adjacent to each other in a specific direction. For this reason, for example, from the viewpoint of simplifying the configuration of a vehicle lamp, a plurality of light sources corresponding to a plurality of adjacently arranged phase modulation elements may be arranged in parallel. In this case, the light from the light source can be made to enter the phase modulation element without using a light guiding optical system that reflects the incident light and guides it to a desired position. In this vehicle lamp, as described above, the longitudinal direction of each of the incident surfaces of the phase modulating elements arranged adjacent to each other in parallel is parallel to the specific direction. Therefore, the distance between the centers of adjacent phase modulation elements can be made longer than in the case where the longitudinal direction of each of the plurality of phase modulation elements arranged in parallel is perpendicular to the specific direction. Therefore, in the case where multiple light sources are arranged in parallel as described above, compared to the case where the longitudinal direction of each of the incident surfaces of the plurality of phase modulation elements arranged in parallel is perpendicular to the specific direction, The distance between adjacent light sources can be increased. Therefore, in this vehicle lamp, the light source is made larger, compared to the case where the longitudinal direction of each of the incident surfaces of the plurality of phase modulation elements arranged in parallel is perpendicular to the specific direction. It is possible to prevent adjacent light sources from interfering with each other, or to prevent the light sources from being overheated due to thermal interference between adjacent light sources.

A vehicular lamp according to a third aspect of the present invention includes a plurality of light sources that emit light having different wavelengths from each other, and diffracts the light emitted from each of the plurality of light sources, so that each of the plurality of lights can be set in a predetermined manner. at least one phase modulation element having a light distribution pattern, and the size of the incident spot on the phase modulation element of the at least two lights having different wavelengths is different from each other.

According to this vehicle lamp, it is allowed that the sizes of the incident spots of light having different wavelengths incident on the phase modulation element are different. Therefore, it is possible to eliminate the provision of optical components for adjusting the size of the incident spot of light having different wavelengths, and an increase in the number of components can be suppressed.

In the vehicle lamp according to the third aspect, the incident spots of the plurality of lights may all have different sizes.

In this case, the size of the spot diameter can be adjusted more effectively, and an increase in the number of parts can be more effectively suppressed.

Furthermore, in the vehicle lamp according to the third aspect, at least two of the lights may be incident on a common phase modulation element.

In this way, by making different lights incident on a common phase modulation element, the number of phase modulation elements can be reduced.

Furthermore, in the vehicle lamp according to the third aspect, the phase modulation element may be an LCOS (Liquid Crystal On Silicon).

In this way, by using the LCOS as the phase modulation element, it becomes possible to change the phase modulation pattern of the phase modulation element as appropriate. Further, a predetermined light distribution pattern can be formed by making different lights incident on a common phase modulation element.

Further, in the vehicle lamp according to the third aspect, among the at least two lights whose incident spot sizes are different from each other, the incident spot of the light having a larger total luminous flux number may be made larger.

In this case, the energy of each light beam per unit area of the incident surface of the phase modulation element can be nearly equal. Therefore, it is possible to prevent a specific phase modulation element from deteriorating faster than other phase modulation elements.

Further, in the vehicle lamp according to the third aspect, among the at least two lights whose incident spot sizes are different from each other, the incident spot of the light may be made smaller as the light has a longer optical path length to the phase modulation element. .

The longer the optical path length to the phase modulation element, the greater the amount of movement of the spot on the phase modulation element when the light source is shaken. Therefore, by making the spot diameter smaller as the optical path length of the light to the phase modulation element becomes longer, it is possible to suppress the spot diameter from extending beyond the phase modulation element when the light source is shaken.

Furthermore, in the vehicle lamp according to the third aspect, among the at least two lights whose incident spots have different sizes, the light whose incident spot is smaller may be emitted from more of the light sources.

In this case, it becomes possible to receive all the light emitted from a larger number of light sources without making the phase modulation element that receives the light emitted from a larger number of light sources larger than other phase modulation elements. .

Furthermore, in the vehicle lamp according to the third aspect, when the incident spots of the plurality of lights all have different sizes, the incident spots of the light having a longer wavelength may be smaller.

In this case, color blurring of light can be suppressed.

A vehicle lamp according to a fourth aspect of the present invention includes a light source that emits light of a predetermined wavelength, and a phase modulation element that makes the light a predetermined light distribution pattern by diffracting the light emitted from the light source. and a spot moving unit that moves an incident spot of the light on the phase modulation element relative to the phase modulation element, the phase modulation element being divided into modulation units that form the light distribution pattern. and at least one of the modulation sections is included within the incident spot.

According to this vehicle lamp, since at least one modulation section is included in the incident spot, the same light distribution pattern can be formed even if the position of the incident spot moves. Further, according to this vehicle lamp, since the incident spot moves relative to the phase modulation element, it is possible to suppress the light from being concentrated on a specific area of the phase modulation element, and the specific area is High temperature can be suppressed. Therefore, the occurrence of areas where it is difficult to form a predetermined light distribution pattern is suppressed, and it becomes easier to obtain a desired light distribution pattern.

In the vehicle lamp according to the fourth aspect, it is preferable that the distance over which the incident spot moves relative to each other is equal to or greater than the radius of the incident spot.

The power distribution of light in an incident spot is generally not uniform, and for example, a predetermined region such as the central region of the incident spot tends to have a peak power region. Considering the size of this peak area, if the distance that the incident spot moves relative to the phase modulation element is equal to or greater than the radius of the incident spot, it is possible to suppress the peak areas from overlapping before and after the relative movement. , temperature increase in a specific region of the phase modulation element can be effectively suppressed.

Furthermore, in the vehicle lamp according to the fourth aspect, when the distance over which the incident spot moves relative to each other is equal to or greater than the radius of the incident spot, it is preferable that the distance is equal to or greater than the diameter of the incident spot.

In this case, since a part of the incident spot after relative movement and a part of the incident spot before relative movement are suppressed from overlapping, heating of a specific area of the phase modulation element is more effectively suppressed. can be done.

Furthermore, in the vehicle lamp according to the fourth aspect, the incident spot may be periodically moved relative to each other.

In this case, since the incident spot periodically moves relative to each other, it is possible to further suppress light from being incident on a specific region of the phase modulation element for a long period of time. For this reason, it can be effectively suppressed that the specific region becomes high in temperature.

Further, in the vehicle lamp according to the fourth aspect, the spot moving section may relatively move the incident spot in two or more directions.

In this case, the incident spot can be relatively moved over a wider range than when the incident spot is relatively moved in only one direction. Therefore, it can be effectively suppressed that a specific region of the phase modulation element becomes high in temperature.

Furthermore, in the vehicle lamp according to the fourth aspect, the phase modulation element may be LCOS (Liquid Crystal On Silicon).

LCOS is a phase modulation element that produces a refractive index difference in a liquid crystal layer by changing the orientation pattern of liquid crystal molecules. In such an LCOS, when the temperature of a specific region increases, the change in the orientation pattern in that region increases, which may make it difficult to obtain a desired light distribution pattern. However, as described above, since the light is prevented from entering a specific region in a concentrated manner, it becomes easier to obtain a desired light distribution pattern even when the phase modulation element is an LCOS.

Furthermore, in the vehicle lamp according to the fourth aspect, the spot moving section may move the light source.

Light sources tend to be lighter than phase modulation elements. Therefore, by configuring the spot moving section to move the light source, it may be easier to relatively move the incident spot. However, if the incident spot moves relative to the phase modulation element, the spot moving section may be configured to move the phase modulation element.

Further, in the vehicle lamp according to the fourth aspect, when the spot moving unit moves the light source as described above, the light source further includes a circuit board that supplies power to the light source, and the light source moves with respect to the circuit board. It's okay.

In this case, it is possible to move only the light source without moving the circuit board.

Furthermore, in the vehicle lamp according to the fourth aspect, when the spot moving section moves the light source as described above, the circuit board may include an elastic connection section to which the light source is electrically connected.

This may allow the light source to move relative to the circuit board.

Further, in the vehicle lamp according to the fourth aspect, the vehicle lamp may include a plurality of the light sources that emit light of different wavelengths, and the phase modulation element may be provided for each of the plurality of light sources.

By providing a plurality of light sources that emit light of different wavelengths, it is possible to generate light of a desired color. Moreover, by providing a phase modulation element for each of these light sources, it may become easy to adjust the light distribution pattern for each light source.

Further, in the vehicle lamp according to the fourth aspect, the vehicle lamp includes a plurality of the light sources that emit light of different wavelengths, and at least two of the plurality of light sources emit the light in a predetermined manner. The plurality of lights that are switched periodically and are emitted from the at least two light sources may be incident on a common phase modulation element.

By providing a plurality of light sources that emit light of different wavelengths, it is possible to generate light of a desired color. In addition, by using a common phase modulation element to receive light from at least two light sources, the number of phase modulation elements installed in vehicle lamps can be reduced, reducing the number of parts and cost. It is possible.

1 is a diagram schematically showing a vehicle lamp according to a first embodiment as a first aspect of the present invention. FIG. 2 is an enlarged view of the optical system unit shown in FIG. 1. FIG. 3 is a front view of the phase modulation element assembly shown in FIG. 2. FIG. 4 is a diagram schematically showing a part of a cross section in the thickness direction of the phase modulation element assembly shown in FIG. 3. FIG. It is a figure showing a light distribution pattern. FIG. 3 is a diagram similar to FIG. 2 showing an optical system unit in a second embodiment as a first aspect of the present invention. It is a front view of the phase modulation element in 3rd Embodiment as a 1st aspect of this invention. FIG. 3 is a diagram similar to FIG. 2 showing an optical system unit in a fourth embodiment as a second aspect of the present invention. 9 is a front view of the phase modulation element assembly shown in FIG. 8. FIG. It is a figure which shows roughly the optical system unit in 5th Embodiment as a 2nd aspect of this invention. 11 is a front view of the phase modulation element assembly shown in FIG. 10. FIG. It is a figure which shows the optical system unit in 6th Embodiment as the 2nd aspect of this invention similarly to FIG. It is a figure which shows a part of lamp unit in 7th Embodiment as a 3rd aspect of this invention. FIG. 14 is a front view schematically showing the phase modulation element shown in FIG. 13 together with an incident spot of light incident on the phase modulation element. FIG. 14 is a diagram similar to FIG. 13 showing a part of a lamp unit of a vehicle lamp according to an eighth embodiment as a third aspect of the present invention. FIG. 16 is a front view schematically showing the phase modulation element shown in FIG. 15 together with an incident spot of light incident on the phase modulation element. FIG. 14 is a diagram similar to FIG. 13 showing a part of a lamp unit of a vehicle lamp according to a ninth embodiment as a third aspect of the present invention. FIG. 15 is a front view showing a phase modulation element according to a tenth embodiment as a third aspect of the present invention, along with an incident spot of light incident on the phase modulation element, from the same viewpoint as FIG. 14; 16 is a diagram showing another example using the phase modulation element shown in FIG. 15 from the same viewpoint as FIG. 16. FIG. It is a figure which shows a part of lamp unit in 11th Embodiment as the 4th aspect of this invention. 21 is a front view schematically showing a part of the circuit board shown in FIG. 20. FIG. 21 is a front view schematically showing the phase modulation element shown in FIG. 20. FIG. 21 is a diagram similar to FIG. 20 showing a part of a lamp unit of a vehicle lamp according to a twelfth embodiment as a fourth aspect of the present invention. FIG. 21 is a diagram similar to FIG. 20 showing a part of a lamp unit of a vehicle lamp according to a thirteenth embodiment as a fourth aspect of the present invention. FIG.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments for implementing a vehicle lamp according to the present invention will be illustrated together with the accompanying drawings. The embodiments illustrated below are provided to facilitate understanding of the present invention, and are not intended to be interpreted as limiting the present invention. The present invention can be modified and improved from the following embodiments without departing from the spirit thereof. Note that in the drawings referred to below, the dimensions of each member may be shown with different dimensions to facilitate understanding.

(First embodiment)
FIG. 1 is a diagram showing a vehicle lamp according to a first embodiment as a first aspect, and is a diagram schematically showing a vertical cross section of the vehicle lamp. The vehicle lamp of this embodiment is a headlamp for an automobile. 2. Description of the Related Art Automobile headlights are generally provided at the front of the vehicle in the left and right directions, and the left and right headlights are generally symmetrical in the left and right direction. Therefore, in this embodiment, one headlamp will be described. As shown in FIG. 1, the vehicle headlamp 1 of this embodiment includes a housing 10 and a lamp unit 20 as main components.

The housing 10 mainly includes a lamp housing 11, a front cover 12, and a back cover 13. The front of the lamp housing 11 is open, and a front cover 12 is fixed to the lamp housing 11 so as to close the opening. Further, a smaller opening is formed at the rear of the lamp housing 11 than at the front, and the back cover 13 is fixed to the lamp housing 11 so as to close the opening.

A space formed by the lamp housing 11, a front cover 12 that closes the front opening of the lamp housing 11, and a back cover 13 that closes the rear opening of the lamp housing 11 is a lamp chamber R. A lamp unit 20 is housed inside.

The lamp unit 20 of this embodiment mainly includes a heat sink 30, a cooling fan 35, a cover 36, and an optical system unit 50, and is fixed to the housing 10 by a structure not shown.

The heat sink 30 has a metal base plate 31 extending generally horizontally, and a plurality of radiation fins 32 are provided integrally with the base plate 31 on the lower surface side of the base plate 31 . The cooling fan 35 is arranged with a gap between it and the radiation fins 32 and is fixed to the heat sink 30. The heat sink 30 is cooled by the airflow caused by the rotation of the cooling fan 35. Further, a cover 36 is arranged on the upper surface of the base plate 31 of the heat sink 30.

The cover 36 is fixed onto the base plate 31 of the heat sink 30. The cover 36 has a generally rectangular shape and is made of metal such as aluminum. An optical system unit 50 is housed in the space inside the cover 36. An opening 36H through which light emitted from the optical system unit 50 can pass is formed in the front part of the cover 36. Note that in order to give the inner walls of the cover 36 light absorption properties, it is preferable that these inner walls be subjected to black alumite processing or the like. Since the inner walls of the cover 36 have light absorbing properties, even if light is irradiated onto these inner walls due to unintended reflection or refraction, the irradiated light will be reflected and emitted from the opening 36H in an unintended direction. may be suppressed.

FIG. 2 is an enlarged view of the optical system unit shown in FIG. 1. Note that, in FIG. 2, the description of the heat sink 30, cover 36, etc. is omitted for easy understanding. As shown in FIG. 2, the optical system unit 50 of this embodiment includes a first light emitting optical system 51R, a second light emitting optical system 51G, a third light emitting optical system 51B, a light guide optical system 155, and a plurality of A phase modulation element assembly 54 formed by unitizing phase modulation elements is provided.

The first light emitting optical system 51R includes a first light source 52R and a first collimator lens 53R. The first light source 52R is a laser element that emits laser light in a predetermined wavelength band, and in this embodiment, it is a semiconductor laser that emits red laser light with a peak power wavelength of 638 nm, for example. Note that the optical system unit 50 has a circuit board (not shown), and the first light source 52R is mounted on the circuit board.

The first collimating lens 53R is a lens that collimates the fast axis direction and the slow axis direction of the laser beam emitted from the first light source 52R. Red light LR emitted from the first collimator lens 53R is emitted from the first light emitting optical system 51R. Instead of the first collimating lens 53R, a collimating lens for collimating the fast axis direction of the laser beam and a collimating lens for collimating the slow axis direction of the laser beam may be provided separately.

The second light emitting optical system 51G includes a second light source 52G and a second collimating lens 53G, and the third light emitting optical system 51B includes a third light source 52B and a third collimating lens 53B. Each of the light sources 52G and 52B is a laser element that emits laser light in a predetermined wavelength band. In this embodiment, the second light source 52G is a semiconductor laser that emits a green laser beam with a peak power wavelength of 515 nm, for example, and the third light source 52B emits a blue laser beam with a peak power wavelength of 445 nm, for example. It is considered to be a semiconductor laser. Therefore, in this embodiment, the three light sources 52R, 52G, and 52B emit laser beams in different predetermined wavelength bands. The light sources 52G and 52B are each mounted on the circuit board described above, similarly to the first light source 52R described above.

The second collimating lens 53G is a lens that collimates the fast axis direction and the slow axis direction of the laser beam emitted from the second light source 52G, and the third collimating lens 53B is a lens that collimates the fast axis direction and the slow axis direction of the laser beam emitted from the third light source 52B. This is a lens that collimates in the slow axis direction. Green light LG emitted from the second collimating lens 53G is emitted from the second light emitting optical system 51G, and blue light LB emitted from the third collimating lens 53B is emitted from the third light emitting optical system 51B. Instead of these collimating lenses 53G and 53B, a collimating lens for collimating the fast axis direction of the laser beam and a collimating lens for collimating the slow axis direction of the laser beam may be provided separately.

The light guiding optical system 155 combines the light LR emitted from the first light emitting optical system 51R, the light LG emitted from the second light emitting optical system 51G, and the light LB emitted from the third light emitting optical system 51B into a phase modulation element set. The light is guided to the body 54. The light guide optical system 155 of this embodiment includes a reflection mirror 155m, a first optical element 155f, and a second optical element 155s. The reflecting mirror 155m reflects the light LR emitted from the first light emitting optical system 51R. The first optical element 155f transmits the light LR reflected by the reflection mirror 155m, and reflects the light LG emitted from the second light emitting optical system 51G. The second optical element 155s transmits the light LR transmitted through the first optical element 155f and the light LG reflected by the first optical element 155f, and reflects the light LB emitted from the third light emitting optical system 51B. Examples of the first optical element 155f and the second optical element 155s include a wavelength selection filter in which an oxide film is laminated on a glass substrate. By controlling the type and thickness of this oxide film, it is possible to create a configuration in which light with a wavelength longer than a predetermined wavelength is transmitted and light with a wavelength shorter than this wavelength is reflected.

The light guide optical system 155 of this embodiment outputs these lights LR, LG, and LB in parallel in the left and right direction without multiplexing them, and makes these lights LR, LG, and LB enter the phase modulation element assembly 54. let In this embodiment, these lights LR, LG, and LB are arranged in parallel in a direction perpendicular to the paper surface of FIG. In FIG. 2, the light LR is shown by a solid line, the light LG is shown by a broken line, and the light LB is shown by a chain line, and these lights LR, LG, and LB are shown offset.

The phase modulation element assembly 54 diffracts the incident light to form a predetermined light distribution pattern. The phase modulation element assembly 54 of this embodiment is arranged so that the entrance surface EF into which light enters is inclined at approximately 45 degrees with respect to the vertical direction, and the lights LR, LG, and LB emitted from the light guide optical system 155 are The light is incident on the entrance plane EF. Incidentally, the entrance plane EF may be non-parallel to the horizontal direction; for example, the phase modulation element assembly 54 may be arranged so that the entrance plane EF is approximately parallel to the vertical direction. In this embodiment, the optical path length from this phase modulation element assembly 54 to the first light source 52R of the first light emitting optical system 51R is the same as the optical path length from the phase modulation element assembly 54 to the second light source 52G of the second light emitting optical system 51G. longer than the optical path length. Further, the optical path length from the phase modulating element assembly 54 to the second light source 52G of the second light emitting optical system 51G is longer than the optical path length from the phase modulating element assembly 54 to the third light source 52B of the third light emitting optical system 51B. long.

As described above, the phase modulation element assembly 54 includes a plurality of phase modulation elements. Specifically, the phase modulating element assembly 54 includes a phase modulating element that diffracts the light LR from the first light emitting optical system 51R and makes the light LR into a predetermined light distribution pattern, and a phase modulating element that diffracts the light LR from the first light emitting optical system 51R, and A phase modulation element that diffracts the light LG to make the light LG a predetermined light distribution pattern, and a phase modulation element that diffracts the light LB from the third light emitting optical system 51B and makes the light LB a predetermined light distribution pattern. Contains. These three phase modulation elements are arranged in one direction, and the entrance surface EF of the phase modulation element assembly 54 is constituted by the light entrance surface of these phase modulation elements.

In this embodiment, each of these three phase modulation elements is a reflective phase modulation element that reflects and diffracts incident light and emits the light. ). Therefore, the phase modulation element assembly 54 diffracts the lights LR, LG, and LB incident on the entrance surface EF by the corresponding phase modulation elements, and the first light DLR from which the red light LR is diffracted and the green light A second light DLG in which LG is diffracted and a third light DLB in which blue light LB is diffracted are emitted from the entrance surface EF. In this way, the lights DLR, DLG, and DLB emitted from the phase modulation element assembly 54 are emitted from the optical system unit 50. In addition, in FIGS. 1 and 2, the first light DLR is shown by a solid line, the second light DLG is shown by a broken line, and the third light DLB is shown by a dashed line. Shown offset.

Next, the configuration of the phase modulation element assembly 54 of this embodiment will be described in detail.

FIG. 3 is a front view of the phase modulation element assembly shown in FIG. 2. Note that FIG. 3 is a front view of the phase modulation element assembly 54 seen from the side of the entrance plane EF into which light enters, and in FIG. 3, the phase modulation element assembly 54 is schematically shown. The phase modulation element assembly 54 of this embodiment is formed into a generally rectangular shape that is elongated in the horizontal direction when viewed from the front, and the entire area when viewed from the front is the entrance plane EF. Therefore, it can be understood that the entrance surface EF of the phase modulation element assembly 54 is formed into a generally rectangular shape that is elongated in the horizontal direction. Hereinafter, in this specification, when the phase modulation element assembly 54 is viewed from the front, a direction parallel to the horizontal direction will be referred to as a horizontal direction, and a direction perpendicular to this horizontal direction will be referred to as a vertical direction. Therefore, the horizontal direction is a direction parallel to the horizontal direction, and the vertical direction is a direction parallel to the direction in which the vertical direction is projected onto the entrance plane EF, and is a direction parallel to the vertical direction in this front view.

The phase modulating element assembly 54 of this embodiment includes a first phase modulating element 54R corresponding to the first light emitting optical system 51R, a second phase modulating element 54G corresponding to the second light emitting optical system 51G, and a third light emitting optical system 54R. It has a third phase modulation element 54B corresponding to the system 51B. The first phase modulation element 54R, the second phase modulation element 54G, and the third phase modulation element 54B are arranged adjacent to each other in the horizontal direction. A three-phase modulation element 54B is connected thereto. In other words, the phase modulation element assembly has a configuration in which these phase modulation elements 54R, 54G, and 54B are integrally formed. A drive circuit 60R is electrically connected to this phase modulation element assembly 54. The drive circuit 60R includes a scanning line drive circuit connected to the horizontal side of the phase modulation element assembly 54 and a data line drive circuit connected to one side of the phase modulation element assembly 54 in the vertical direction. Power is supplied to each of the phase modulation elements 54R, 54G, and 54B constituting the phase modulation element assembly 54 via this drive circuit 60R.

The vertical width of the first phase modulating element 54R, the vertical width of the second phase modulating element 54G, and the vertical width of the third phase modulating element 54B are the vertical width H54 of the phase modulating element assembly 54. is considered to be the same as The horizontal width WR of the first phase modulation element 54R, the horizontal width WG of the second phase modulation element 54G, and the horizontal width WB of the third phase modulation element 54B are in the vertical direction of the phase modulation element assembly 54. width H54. That is, these phase modulation elements 54R, 54G, and 54B are formed into a generally rectangular shape that is elongated in the vertical direction, that is, the vertical direction. As described above, the entire area of the phase modulation element assembly 54 in front view is defined as the entrance plane EF, and the entrance plane EF of the phase modulation element assembly 54 is defined by the light incidence plane of these phase modulation elements 54R, 54G, and 54B. Therefore, each of the light incident surfaces of the phase modulation elements 54R, 54G, and 54B is formed into a generally rectangular shape that is elongated in the vertical direction, that is, the vertical direction. Therefore, the vertical width H54 of the entrance surface of the first phase modulation element 54R is made larger than the horizontal width WR of the entrance surface of the first phase modulation element 54R, and the width H54 of the entrance surface of the second phase modulation element 54G is The vertical width H54 is larger than the horizontal width WG of the entrance surface of the second phase modulation element 54G, and the vertical width H54 of the entrance surface of the third phase modulation element 54B is larger than the width WG of the entrance surface of the third phase modulation element 54B. It is larger than the width WB in the horizontal direction of the incident surface. In this embodiment, the horizontal width WG of the second phase modulation element 54G and the vertical width WB of the third phase modulation element 54B are approximately the same, and the horizontal width WR of the first phase modulation element 54R is It is larger than these widths WG and WB. Therefore, the lateral widths WG and WB of the entrance surfaces of the phase modulation elements 54G and 54B are approximately the same, and the lateral width WR of the entrance surface of the first phase modulation element 54R is larger than these widths WG and WB. considered to be large.

The first phase modulation element 54R is composed of a plurality of modulation sections MPR divided into a matrix. The second phase modulation element 54G is composed of a plurality of modulation sections MPG divided into a matrix, and the third phase modulation element 54B is composed of a plurality of modulation sections MPB divided into a matrix. In this embodiment, these modulation units MPR, MPG, and MPB are squares of the same size. Therefore, the number of modulation units MPR arranged in parallel in the vertical direction is greater than the number of modulation units MPR arranged in parallel in the horizontal direction. Further, the number of modulation units MPG arranged in parallel in the vertical direction is greater than the number of modulation units MPG arranged in parallel in the horizontal direction, and the number of modulation units MPB arranged in parallel in the vertical direction is greater than the number of modulation units MPB arranged in parallel in the horizontal direction. The number of MPBs is greater than the number of MPBs. Each of the modulation units MPR, MPG, and MPB includes a plurality of dots arranged in a matrix, and diffracts and emits light incident on the modulation units MPR, MPG, and MPB.

The red light LR emitted from the light guide optical system 155 enters the first phase modulation element 54R, and the first phase modulation element 54R emits the first light DLR obtained by diffracting the light LR. The green light LG emitted from the light guide optical system 155 enters the second phase modulation element 54G, and the second phase modulation element 54G emits second light DLG obtained by diffracting this light LG. The blue light LB emitted from the light guide optical system 155 enters the third phase modulation element 54B, and the third phase modulation element 54B emits third light DLB which is the diffracted light LB.

FIG. 3 shows an incident spot SR that is an area that is irradiated with red light LR, an incident spot SG that is an area that is irradiated with green light LG, and an incident spot that is an area that is irradiated with blue light LB. SB is shown. In this embodiment, as described above, the light sources 52R, 52G, and 52B are semiconductor lasers, so the laser beams emitted from the light sources 52R, 52G, and 52B propagate while expanding in an approximately elliptical shape. Furthermore, although the fast axis direction and slow axis direction of the laser beams emitted from these light sources 52R, 52G, and 52B are collimated by collimating lenses 53R, 53G, and 53B, the shapes of these laser beams are not adjusted. The lights LR, LG, and LB whose shapes have not been adjusted in this way are emitted from the light emitting optical systems 51R, 51G, and 51B, and are incident on the phase modulation element assembly 54 via the light guiding optical system 155, respectively. In this embodiment, since the shapes of these lights LR, LG, and LB are not adjusted in the light guide optical system 155, the shapes of the incident spots SR, SG, and SB are each approximately elliptical.

Further, in this embodiment, the size of the generally elliptical incident spot SR is set to be large enough to include at least one modulation part MPR, and the long axis LAR of this incident spot SR is generally parallel to the lateral direction. . In other words, the incident spot SR has a generally elliptical shape that is elongated in the horizontal direction, and the longitudinal direction and the vertical direction of the incident spot SR are non-parallel. Further, the size of the generally elliptical incident spot SG is set to be large enough to include at least one modulation section MPG, and the long axis LAG of this incident spot SG is generally parallel to the longitudinal direction. In other words, the incident spot SG has a generally elliptical shape that is elongated in the vertical direction, and the longitudinal direction and the horizontal direction of the incident spot SG are non-parallel. Furthermore, the size of the generally elliptical incident spot SB is set to be large enough to include at least one modulation section MPB, and the long axis LAB of this incident spot SB is generally parallel to the longitudinal direction. In other words, the incident spot SB has a generally elliptical shape that is elongated in the vertical direction, and the longitudinal direction and the horizontal direction of the incident spot SB are non-parallel.

Further, in this embodiment, the vertical width SHR of the incident spot SR on the first phase modulation element 54R is made smaller than the vertical width SHG of the incident spot SG on the second phase modulation element 54G. Further, the vertical width SHG of the incident spot SG is approximately the same as the vertical width SHB of the incident spot SB on the third phase modulation element 54B. Note that the width SHG and the width SHB may be different from each other.

FIG. 4 is a diagram schematically showing a part of a cross section in the thickness direction of the phase modulation element assembly shown in FIG. 3. FIG. As shown in FIG. 4, the phase modulation element assembly 54 of this embodiment includes a silicon substrate 62, a drive circuit layer 63, a plurality of electrodes 64, a reflective film 65, a liquid crystal layer 66, and a transparent electrode 67. , and a translucent substrate 68 as main components.

The plurality of electrodes 64 are arranged in a matrix on one surface of the silicon substrate 62 in one-to-one correspondence with each dot. The drive circuit layer 63 is a layer in which circuits connected to the scanning line drive circuit and the data line drive circuit of the drive circuit 60R shown in FIG. 3 are arranged, and is arranged between the silicon substrate 62 and the plurality of electrodes 64. Ru. The transparent substrate 68 is disposed on one side of the silicon substrate 62 to face the silicon substrate 62, and is made of, for example, a glass substrate. The transparent electrode 67 is arranged on the surface of the transparent substrate 68 on the silicon substrate 62 side. The liquid crystal layer 66 has liquid crystal molecules 66a and is arranged between the plurality of electrodes 64 and the transparent electrode 67. The reflective film 65 is arranged between the plurality of electrodes 64 and the liquid crystal layer 66, and is made of, for example, a dielectric multilayer film. The light LR emitted from the light guide optical system 155 enters from the entrance surface EF of the transparent substrate 68 on the side opposite to the silicon substrate 62 side.

As shown in FIG. 4, light LR entering from the incident surface EF on the side opposite to the silicon substrate 62 side of the transparent substrate 68 is transmitted through the transparent electrode 67 and the liquid crystal layer 66, reflected by the reflective film 65, and then The light passes through the layer 66 and the transparent electrode 67 and is emitted from the transparent substrate 68 . When a voltage is applied between a specific electrode 64 and the transparent electrode 67, the orientation of the liquid crystal molecules 66a of the liquid crystal layer 66 located between the specific electrode 64 and the transparent electrode 67 changes. Due to this change in the orientation of the liquid crystal molecules 66a, the refractive index of the liquid crystal layer 66 located between the electrode 64 and the transparent electrode 67 changes, and the optical path length of the light LR passing through the liquid crystal layer 66 changes. Therefore, when the light LR passes through the liquid crystal layer 66 and exits from the liquid crystal layer 66, the phase of the light LR that exits from the liquid crystal layer 66 can change from the phase of the light LR that enters the liquid crystal layer 66. As described above, since the plurality of electrodes 64 are arranged for each dot DT in each modulation section MPR, MPG, MPB, the voltage applied between the electrode 64 corresponding to each dot DT and the transparent electrode 67 is is controlled, the orientation of the liquid crystal molecules 66a changes, and the amount of change in the phase of light emitted from each dot DT can be adjusted according to each dot DT. Since the lights with different phases interfere with each other and are diffracted, the lights emitted from the dots DT interfere with each other and are diffracted, and this diffracted light is emitted from the phase modulation element assembly 54. Therefore, by adjusting the refractive index of the liquid crystal layer 66 in each dot, the phase modulation element assembly 54 diffracts and emits the incident light, and also changes the light distribution pattern of the emitted light to a desired light distribution pattern. obtain. In addition, the phase modulation element assembly 54 changes the refractive index of the liquid crystal layer 66 in each dot to change the light distribution pattern of the emitted light, or changes the direction of the emitted light so that the light is irradiated. You can also change the area that is displayed.

In this embodiment, the same phase modulation pattern is formed in each modulation section MPR in the first phase modulation element 54R of the phase modulation element assembly 54. Further, the same phase modulation pattern is formed in each modulation section MPG in the second phase modulation element 54G, and the same phase modulation pattern is formed in each modulation section MPB in the third phase modulation element 54B. Note that in this specification, a phase modulation pattern refers to a pattern that modulates the phase of incident light. In this embodiment, the phase modulation pattern is a pattern of the refractive index of the liquid crystal layer 66 in each dot DT, and is also a pattern of voltage applied between the electrode 64 and the transparent electrode 67 corresponding to each dot DT. It can be understood. By adjusting this phase modulation pattern, the light distribution pattern of the emitted light can be made into a desired light distribution pattern. In this embodiment, the phase modulation patterns in the modulation units MPR, MPG, and MPB are different from each other.

Specifically, in the present embodiment, each of the phase modulation patterns in the modulation units MPR, MPG, and MPB is composed of the first light DLR emitted from the first phase modulation element 54R and the first light DLR emitted from the second phase modulation element 54G. a phase modulation pattern that diffracts the lights LR, LG, and LB, respectively, so that the combined light of the second light DLG and the third light DLB emitted from the third phase modulation element 54B becomes a low beam light distribution pattern; be done. In other words, the phase modulation elements 54R, 54G, and 54B of the phase modulation element assembly 54 have a low beam light distribution pattern in which the light DLR, DLG, and DLB emitted from the phase modulation elements 54R, 54G, and 54B are combined. The incident lights LR, LG, and LB are each diffracted so that This light distribution pattern also includes the light intensity distribution. Therefore, in this embodiment, the first light DLR emitted from the first phase modulation element 54R overlaps with the low beam light distribution pattern and has a light intensity distribution based on the light intensity distribution of the low beam light distribution pattern. be done. The second light DLG emitted from the second phase modulation element 54G overlaps the low beam light distribution pattern and has a light intensity distribution based on the light intensity distribution of the low beam light distribution pattern. The third light DLB emitted from the third phase modulation element 54B overlaps with the low beam light distribution pattern and has a light intensity distribution based on the light intensity distribution of the low beam light distribution pattern. As described above, these phase modulation elements 54R, 54G, and 54B each have a plurality of modulation sections MPR, MPG, and MPB that form the same phase modulation pattern. The lights LR, LG, and LB are each diffracted so as to form a light distribution pattern. Note that these phase modulation elements 54R, 54G, and 54B are designed so that the outline of the light distribution pattern of the light DLR, DLG, and DLB emitted from the phase modulation elements 54R, 54G, and 54B matches the outline of the light distribution pattern of the low beam. , it is preferable to diffract the incident lights LR, LG, and LB, respectively. In this way, the first phase modulation element 54R emits the light DLR of the red component of the low beam light distribution pattern, the second phase modulation element 54G emits the light DLG of the green component of the low beam light distribution pattern, and the third phase modulation element 54R emits the light DLR of the red component of the low beam light distribution pattern. The element 54B emits blue component light DLB of a low beam light distribution pattern.

Next, light emission by the vehicle headlamp 1 will be explained. Specifically, a case where a low beam is emitted from the vehicle headlamp 1 will be described.

By supplying power to each of the light sources 52R, 52G, and 52B from a power supply (not shown), the first light source 52R emits a red laser beam, the second light source 52G emits a green laser beam, and the third light source 52R emits a red laser beam. The light source 52B emits blue laser light. After being collimated by collimating lenses 53R, 53G, and 53B, the respective laser beams are emitted from light emitting optical systems 51R, 51G, and 51B. Light LR, LG, and LB emitted from the light emitting optical systems 51R, 51G, and 51B enter the light guiding optical system 155.

In the light guide optical system 155, the light LR from the first light emitting optical system 51R is reflected by a reflection mirror 155m, passes through the first optical element 155f and the second optical element 155s, and exits from the light guide optical system 155. The light LR emitted from the light guide optical system 155 in this manner is incident on the first phase modulation element 54R of the phase modulation element assembly 54. That is, the light LR is guided to the first phase modulation element 54R of the phase modulation element assembly 54 by the light guide optical system 155. The light LG from the second light emitting optical system 51G is reflected by the first optical element 155f, passes through the second optical element 155s, and exits from the light guiding optical system 155. The light LG emitted from the light guide optical system 155 in this manner is incident on the second phase modulation element 54G of the phase modulation element assembly 54. That is, the light LG is guided to the second phase modulation element 54G of the phase modulation element assembly 54 by the light guide optical system 155. The light LB from the third light emitting optical system 51B is reflected by the second optical element 155s and exits from the light guiding optical system 155. The light LB emitted from the light guide optical system 155 in this manner enters the third phase modulation element 54B of the phase modulation element assembly 54. That is, the light LB is guided to the third phase modulation element 54B of the phase modulation element assembly 54 by the light guide optical system 155.

The first phase modulating element 54R of the phase modulating element assembly 54 diffracts the light LR that is incident on the first phase modulating element 54R, and emits the first light DLR that is red component light of the low beam light distribution pattern. do. The second phase modulation element 54G diffracts the light LG that is incident on the second phase modulation element 54G, and emits second light DLG that is light of the green component of the low beam light distribution pattern. The third phase modulation element 54B diffracts the light LB that is incident on the third phase modulation element 54B, and emits the third light DLB, which is light of the blue component of the low beam light distribution pattern. In this way, these lights DLR, DLG, and DLB emitted from the phase modulation element assembly 54 are irradiated to the outside of the vehicle headlamp 1 via the front cover 12, respectively. At this time, these lights DLR, DLG, and DLB are irradiated at a focal position a predetermined distance away from the vehicle so that the areas irradiated with each light overlap with each other. This focal point position is, for example, 25 meters away from the vehicle. The combined light of these lights DLR, DLG, and DLB has a low beam light distribution pattern, so the irradiated light becomes a low beam. Note that it is preferable that these lights DLR, DLG, and DLB are irradiated so that the outer shapes of their respective light distribution patterns approximately match each other at this focal position.

FIG. 5 is a diagram showing a light distribution pattern for night lighting. Specifically, FIG. 5(A) is a diagram showing a light distribution pattern for a low beam, and FIG. 5(B) is a diagram showing a light distribution pattern for a high beam. FIG. In FIG. 5, S indicates a horizontal line, and the light distribution pattern is indicated by a thick line. Of the low beam light distribution pattern PL, which is a light distribution pattern for night lighting shown in FIG. It gets lower. In other words, each of the phase modulation elements 54R, 54G, and 54B of the phase modulation element assembly 54 diffracts the light so that the combined light forms a light distribution pattern including the low beam intensity distribution. Note that, as shown by the broken line in FIG. 5, light with lower intensity than the low beam may be emitted from the vehicle headlamp 1 above the position where the low beam is emitted. This light is used as light OHS for visual recognition of signs. In this case, it is preferable that the lights DLR, DLG, and DLB emitted from the phase modulation elements 54R, 54G, and 54B of the phase modulation element assembly 54 include the light OHS for visual recognition of the sign. Further, in this case, it can be understood that the low beam and the light OHS for visualizing the sign form a light distribution pattern for night illumination. Note that the light distribution pattern for night lighting is not only used at night, but also in dark places such as tunnels.

Here, the vehicle vibrates depending on road surface conditions and the like, and the vehicle lamp also vibrates in the same way as the vehicle. Therefore, in the vehicle lamp described in Patent Document 1, the incident spot of the reference light on the hologram element vibrates with respect to the hologram element due to vehicle vibration, and the reference light may not be irradiated to a part of the hologram element. There is. Therefore, with this vehicle lamp, there is a risk that a predetermined light distribution pattern may not be formed due to vibrations of the vehicle, and there is a need to be able to form a predetermined light distribution pattern even if vibrations occur. To meet this requirement, it is conceivable to make the incident spot of the reference light larger so that even if vibration occurs, the entire hologram element is irradiated with the reference light. However, in such a case, a portion of the reference light is not irradiated onto the hologram element, resulting in a decrease in energy efficiency.

Therefore, the vehicle headlamp 1 of the present embodiment as a first aspect includes light sources 52R, 52G, and 52B that emit light, a first phase modulation element 54R, a second phase modulation element 54G, and a third phase modulation element. and a phase modulation element assembly 54 having an element 54B. The first phase modulation element 54R includes a plurality of modulation units MPR that diffracts the light LR from the first light source 52R to form a predetermined light distribution pattern. The second phase modulation element 54G includes a plurality of modulation units MPG that diffracts the light LG from the second light source 52G to form a predetermined light distribution pattern. The third phase modulation element 54B includes a plurality of modulation units MPB that diffracts the light LB from the third light source 52B to form a predetermined light distribution pattern. The vertical width H54 of the entrance surface of the first phase modulation element 54R is larger than the horizontal width WR of the entrance surface. The vertical width H54 of the entrance surface of the second phase modulation element 54G is larger than the horizontal width WG of the entrance surface, and the vertical width H54 of the entrance surface of the third phase modulation element 54B is It is larger than the width WB in the horizontal direction of the incident surface. The size of the incident spot SR of the light LR on the first phase modulation element 54R is set to be large enough to include at least one modulation part MPR, and the size of the incident spot SG of the light LG on the second phase modulation element 54G is , and the size of the incident spot SB of the light LB on the third phase modulation element 54B is made large enough to include at least one modulation part MPB. At least some of the plurality of modulation units MPR are arranged in parallel in the vertical direction, at least some of the plurality of modulation units MPG are arranged in parallel in the longitudinal direction, and at least some of the plurality of modulation units MPB are arranged in parallel in the longitudinal direction.

The vertical amplitude of vehicle vibration tends to be larger than the horizontal amplitude, and the vehicle headlamp 1 also vibrates in the same way as the vehicle. Therefore, the incident spots SR, SG, and SB of the light beams LR, LG, and LB on each of the phase modulation elements 54R, 54G, and 54B of the phase modulation element assembly 54 tend to vibrate in the vertical direction rather than in the horizontal direction. That is, the incident spots SR, SG, and SB tend to vibrate more in the vertical direction, which is a direction parallel to the direction in which the vertical direction is projected onto the entrance plane EF, than in the lateral direction, which is parallel to the horizontal direction. In the vehicle headlamp 1 of this embodiment, as described above, the vertical width H54 of the entrance surface of each phase modulation element 54R, 54G, 54B is the horizontal width WR, WG of the entrance surface, It is said to be larger than WB. Therefore, in the vehicle headlamp 1 of this embodiment, even when the incident spots SR, SG, and SB vibrate in the vertical direction in response to vibrations of the vehicle, some of the incident spots SR, SG, and SB are out of phase. It is possible to prevent the modulation elements 54R, 54G, and 54B from protruding from the incident plane, and it is possible to prevent the energy efficiency from decreasing. Further, in the vehicle headlamp 1 of the present embodiment, as described above, each of the incident spots SR, SG, and SB has a size that can include at least one modulation section MPR, MPG, and MPB. be done. Further, at least a portion of each of the modulation units MPR, MPG, and MPB are arranged in parallel in the vertical direction. Therefore, in the vehicle headlamp 1 of the present embodiment, even if the incident spots SR, SG, and SB move in the vertical direction in response to vibrations of the vehicle, the light LR may not be incident on any of the modulation units MPR. , the light LG may be incident on any of the modulation units MPG, and the light LB may be incident on any of the modulation units MPG. Therefore, the vehicle headlamp 1 of this embodiment can form the low beam light distribution pattern PL even in such a case.

Further, the vehicle headlamp 1 of the present embodiment as the first aspect has a plurality of light sources 52R, 52G, and 52B, and the phase modulation element assembly 54 receives the light LR from the first light source 52R. a second phase modulation element 54G into which light LG from a second light source 52G is incident, and a third phase modulation element 54B into which light LB from a third light source 52B is incident. That is, these phase modulation elements 54R, 54G, and 54B of the phase modulation element assembly 54 are provided for each light source 52R, 52G, and 52B. Further, the optical path length from the phase modulation element assembly 54 to the first light source 52R is longer than the optical path length from the phase modulation element assembly 54 to the second light source 52G, and from the phase modulation element assembly 54 to the second light source 52G. The optical path length is longer than the optical path length from the phase modulation element assembly 54 to the third light source 52B. In other words, the optical path length from the first phase modulation element 54R to the first light source 52R is longer than the optical path length from the second phase modulation element 54G to the second light source 52G, and from the second phase modulation element 54G to the second light source 52G. The optical path length is longer than the optical path length from the third phase modulation element 54B to the third light source 52B. Further, the vertical width SHR of the incident spot SR on the first phase modulating element 54R is the vertical width SHG of the incident spot SG on the second phase modulating element 54G and the vertical width SHG of the incident spot SB on the third phase modulating element 54B. is smaller than the width SHB at . In other words, the vertical width SHR of the incident spot SR in the first phase modulating element 54R, which has the maximum optical path length with respect to the corresponding light source, is the vertical width SHR of the incident spot SG, SB in the other phase modulating elements 54G, 54B. The width shall be less than or equal to the maximum width of SHG and SHB.

The amplitude of vibration of the incident spot relative to the phase modulation element tends to increase as the optical path length between the phase modulation element and the light source becomes longer. In the vehicle headlamp 1 of this embodiment, the vertical width SHR of the incident spot SR in the first phase modulating element 54R, where the amplitude of vibration of the incident spot with respect to the phase modulating element tends to be large, is different from that of the other phase modulating element 54G. , 54B. Therefore, the phase of the incident spot can be adjusted without adjusting the vertical width of the incident surface of the phase modulation elements 54R, 54G, 54B or the optical path length between the phase modulation elements 54R, 54G, 54B and the light sources 52R, 52G, 52B. It is possible to suppress a part of the incident spot SR on the first phase modulating element 54R, in which the amplitude of vibration to the modulating element tends to become large, from protruding from the incident surface of the phase modulating element 54R. Therefore, the size of the phase modulation elements 54R, 54G, 54B and the degree of freedom in the arrangement of the phase modulation elements 54R, 54G, 54B relative to the light sources 52R, 52G, 52B can be improved.

Further, in the vehicle headlamp 1 of the present embodiment as the first aspect, the phase modulation element assembly 54 includes the first phase modulation element 54R and the third phase modulation element 54B connected to the second phase modulation element 54G. These phase modulation elements 54R, 54G, and 54B are integrally formed. Therefore, in the vehicle headlamp 1 of this embodiment, the number of parts can be reduced compared to a case where these phase modulation elements 54R, 54G, and 54B are provided separately.

Further, in the vehicle headlamp 1 of the present embodiment as the first aspect, the incident spot SR on the first phase modulating element 54R has a generally elliptical shape that is elongated in a specific direction, and the incident spot SR is in the longitudinal direction of the incident spot SR. The specific direction is non-parallel to the vertical direction. Therefore, the width SHR of the incident spot SR in the vertical direction can be made smaller than when the vertical direction is parallel to a specific direction, which is the longitudinal direction of the incident spot SR. Therefore, when the incident spot SR vibrates in the vertical direction in response to vibrations of the vehicle, the angle of the incident spot SR becomes It is possible to prevent the portion from protruding from the incident surface of the phase modulation element 54R. In addition, from the viewpoint of suppressing a part of the incident spot SR from protruding from the incident surface of the first phase modulation element 54R in response to vibrations of the vehicle, as in the present embodiment, a specific part of the incident spot SR in the longitudinal direction is It is preferable that the direction and the horizontal direction are parallel to each other.

Further, in the vehicle headlamp 1 of the present embodiment as the first aspect, the incident spot SG on the second phase modulation element 54G has a generally elliptical shape that is elongated in a specific direction, and the incident spot SG has a longitudinal direction. A specific direction and a horizontal direction are considered to be non-parallel. Furthermore, the incident spot SB on the third phase modulation element 54B has a generally elliptical shape elongated in a specific direction, and the specific longitudinal direction of the incident spot SB is non-parallel with the horizontal direction. Ru. Therefore, compared to the case where the horizontal direction is parallel to a specific longitudinal direction of the incident spots SG and SB, it is possible to reduce the width of the phase modulation elements 54G and 54B in the horizontal direction. Therefore, the manufacturing cost of the vehicle headlamp 1 can be reduced. In addition, from the viewpoint of reducing the widths WG and WB in the horizontal direction of the phase modulation elements 54R and 54B, as in this embodiment, the incident spots SG and SB are arranged in a specific direction, which is the longitudinal direction, and in a vertical direction, which is the vertical direction. are preferably parallel.

Further, in the vehicle headlamp 1 of the present embodiment as the first aspect, the number of modulation units MPR arranged in parallel in the vertical direction is greater than the number of modulation units MPR arranged in parallel in the horizontal direction. Further, the number of modulation units MPG arranged in parallel in the vertical direction is greater than the number of modulation units MPG arranged in parallel in the horizontal direction, and the number of modulation units MPB arranged in parallel in the vertical direction is greater than the number of modulation units MPB arranged in parallel in the horizontal direction. The number of MPBs is greater than the number of MPBs.

Therefore, when the incident spot SR vibrates in the vertical direction in response to vehicle vibration, compared to the case where the number of modulation units MPR arranged in parallel in the vertical direction is smaller than the number of modulation units MPR arranged in parallel in the horizontal direction, The light LR from the first light source 52R can be made easier to enter one of the modulators MPR. Further, similarly to the modulation unit MPR, when the incident spot SG vibrates in the vertical direction in response to vibrations of the vehicle, the light LG from the second light source 52G can be made easier to enter one of the modulation units MPG. Further, similarly to the modulation unit MPR, when the incident spot SB vibrates in the vertical direction in response to vibrations of the vehicle, the light LB from the third light source 52B can be made easier to enter one of the modulation units MPB.

(Second embodiment)
Next, a second embodiment as a first aspect of the present invention will be described in detail with reference to FIG. Note that components that are the same or equivalent to those in the first embodiment are given the same reference numerals and redundant explanations will be omitted, unless otherwise specified.

FIG. 6 is a diagram similar to FIG. 2 showing an optical system unit in a second embodiment as the first aspect of the present invention. Note that in FIG. 6, descriptions of the heat sink 30, cover 36, etc. are omitted for easy understanding. As shown in FIG. 6, the optical system unit 50 of this embodiment has the following points: the phase modulation elements 54R, 54G, and 54B are spaced apart from each other, and the light guide optical system 155 is replaced by a combining optical system 55. This is different from the optical system unit 50 of the first embodiment.

Each of the phase modulation elements 54R, 54G, and 54B of this embodiment is an LCOS like the phase modulation elements 54R, 54G, and 54B of the first embodiment. Further, the phase modulation element 54R is formed into a generally rectangular shape that is elongated in the vertical direction when viewed from the front from the side of the entrance surface EFR into which light enters. Therefore, the width in the vertical direction of the entrance surface EFR of the first phase modulation element 54R is made larger than the width in the lateral direction of the entrance surface EFR of the first phase modulation element 54R. A plurality of modulation parts MPR arranged in a matrix are formed in the first phase modulation element 54R, and the number of modulation parts MPR arranged in parallel in the vertical direction in the first phase modulation element 54R is equal to the number of modulation parts MPR arranged in parallel in the horizontal direction. The number is greater than the number of modulation units MPR. The light LR from the first light source 52R enters the first phase modulation element 54R, and the first phase modulation element 54R emits the first light DLR obtained by diffracting the light LR. In this embodiment, as in the first embodiment, the shape of the light LR from the first light source 52R, which is a semiconductor laser, is not adjusted, so the shape of the incident spot SR on the first phase modulation element 54R is approximately elliptical. be done. In this embodiment, similarly to the first embodiment, the size of the generally elliptical incident spot SR is set to be large enough to include at least one modulation part MPR, and the long axis LAR of this incident spot SR is in the horizontal direction. It is assumed to be approximately parallel to the horizontal direction.

The second phase modulation element 54G of this embodiment is formed into a generally rectangular shape that is elongated in the vertical direction when viewed from the front from the side of the entrance surface EFG where light enters. Therefore, the width in the vertical direction of the entrance surface EFR of the second phase modulation element 54G is made larger than the width in the lateral direction of the entrance surface EFR of the second phase modulation element 54G. A plurality of modulation units MPR arranged in a matrix are formed in the second phase modulation element 54G, and the number of modulation units MPG arranged in parallel in the vertical direction in the second phase modulation element 54G is equal to that in parallel in the horizontal direction. The number is greater than the number of modulation units MPG. Light LG from the second light source 52G is incident on the second phase modulation element 54G, and the second phase modulation element 54G emits second light DLG that is the diffracted light LG. In this embodiment, as in the first embodiment, the shape of the light LG from the second light source 52G, which is a semiconductor laser, is not adjusted, so the shape of the incident spot SG on the second phase modulation element 54G is approximately elliptical. be done. In this embodiment, as in the first embodiment, the size of the generally elliptical incident spot SG is set to be large enough to include at least one modulation part MPG, and the long axis LAG of this incident spot SG is in the vertical direction. It is generally parallel to the vertical direction.

The third phase modulation element 54B of this embodiment is formed into a generally rectangular shape that is elongated in the vertical direction when viewed from the front from the side of the entrance surface EFB where light enters. Therefore, the width in the vertical direction of the entrance surface EFB of the third phase modulation element 54B is made larger than the width in the lateral direction of the entrance surface EFB of the third phase modulation element 54B. A plurality of modulation units MPB arranged in a matrix are formed in the third phase modulation element 54B, and the number of modulation units MPB arranged in parallel in the vertical direction in the third phase modulation element 54B is equal to the number of modulation units MPB arranged in parallel in the horizontal direction. The number is greater than the number of modulators MPB. The light LB from the third light source 52B enters the third phase modulation element 54B, and the third phase modulation element 54B emits the third light DLB obtained by diffracting the light LB. In this embodiment, as in the first embodiment, the shape of the light LB from the third light source 52B, which is a semiconductor laser, is not adjusted, so the shape of the incident spot SB on the third phase modulation element 54B is approximately elliptical. be done. In this embodiment, as in the first embodiment, the size of the generally elliptical incident spot SB is set to be large enough to include at least one modulation part MPB, and the long axis LAB of this incident spot SB is in the vertical direction. It is generally parallel to the vertical direction.

The combining optical system 55 of this embodiment includes a first optical element 55f and a second optical element 55s. The first optical element 55f is an optical element that combines the first light DLR emitted from the first phase modulation element 54R and the second light DLG emitted from the second phase modulation element 54G. In this embodiment, the first optical element 55f combines the first light DLR and the second light DLG by transmitting the first light DLR and reflecting the second light DLG. Further, the second optical element 55s is an optical element that combines the first light DLR and second light DLG combined by the first optical element 55f and the third light DLB emitted from the third phase modulation element 54B. It is element. In the present embodiment, the second optical element 55s transmits the first light DLR and the second light DLG combined by the first optical element 55f, and reflects the third light DLB, thereby generating the first light. The DLR, the second optical DLG, and the third optical DLB are combined. Examples of the first optical element 55f and the second optical element 55s include wavelength selection filters in which an oxide film is laminated on a glass substrate. By controlling the type and thickness of this oxide film, it is possible to create a configuration in which light with a wavelength longer than a predetermined wavelength is transmitted and light with a wavelength shorter than this wavelength is reflected.

In this way, the first light DLR, the second light DLG, and the third light DLB are combined in the combining optical system 55, and this light is emitted from the combining optical system 55. In addition, in FIG. 6, the first light DLR is shown by a solid line, the second light DLG is shown by a broken line, and the third light DLB is shown by a dashed line. It is shown.

In the present embodiment, the phase modulation elements 54R, 54G, and 54B have a low beam light distribution pattern in which the light DLR, DLG, and DLB emitted from each of the phase modulation elements 54R, 54G, and 54B are combined by the combining optical system 55. The lights LR, LG, and LB from the light sources 52R, 52G, and 52B are each diffracted so as to become PL. Therefore, the first light DLR, which is the red component light of the low beam light distribution pattern PL, is emitted from the first phase modulation element 54R, and the green component of the low beam light distribution pattern PL is emitted from the second phase modulation element 54G. The second light DLG, which is the light of the low beam, is emitted, and the third light DLB, which is the light of the blue component of the low beam light distribution pattern PL, is emitted from the third phase modulation element 54B.

As described above, these lights DLR, DLG, and DLB are combined in the combining optical system 55, and this combined white light is emitted from the opening 36H of the cover 36, and this light is transmitted to the front of the vehicle through the front cover 12. The light is emitted from the illumination light 1. Since this light has a low beam light distribution pattern PL, the emitted light becomes a low beam.

Similarly to the first embodiment, the vehicle headlamp 1 according to the present embodiment has the advantage that even when the incident spots SR, SG, and SB vibrate in the vertical direction in response to vibrations of the vehicle, the incident spots SR, SG, and SB are It is possible to prevent a portion of the phase modulating elements 54R, 54G, and 54B from protruding from the entrance planes EFR, EFG, and EFB, and it is possible to suppress a decrease in energy efficiency. Furthermore, in the vehicle headlamp 1 of the present embodiment, as in the first embodiment, even when the incident spots SR, SG, and SB vibrate in the vertical direction in response to vibrations of the vehicle, any of the modulation parts Light LR may be incident on MPR, light LG may be incident on any modulation unit MPG, and light LB may be incident on any modulation unit MPB. Therefore, the vehicle headlamp 1 of this embodiment can form the low beam light distribution pattern PL even in such a case.

(Third embodiment)
Next, a third embodiment as the first aspect of the present invention will be described in detail. Note that components that are the same or equivalent to those in the first embodiment are given the same reference numerals and redundant explanations will be omitted, unless otherwise specified. The optical system unit 50 of this embodiment mainly differs from the optical system unit 50 of the first embodiment in that it includes one phase modulation element 54S instead of the phase modulation element assembly 54.

FIG. 7 is a front view of a phase modulation element in a third embodiment as a first aspect of the present invention. Note that FIG. 7 is a front view of the phase modulation element 54S viewed from the incident surface side where light enters, and in FIG. 7, the phase modulation element 54S is schematically shown.

In this embodiment, the configuration of the phase modulation element 54S is similar to that of the phase modulation element 54R of the first embodiment. The phase modulating element 54S of this embodiment is formed into a generally rectangular shape that is elongated in the vertical direction, which is the vertical direction, when viewed from the front from the incident surface side where light enters. Therefore, the vertical width H54 of the entrance surface of the phase modulation element 54S is made larger than the horizontal width WS of the entrance surface of the phase modulation element 54S. Similar to the phase modulation element 54R of the first embodiment, the phase modulation element 54S includes a plurality of modulation sections MPS arranged in a matrix. The number of modulation units MPS arranged in parallel in the vertical direction is greater than the number of modulation units MPS arranged in parallel in the horizontal direction. Like the modulation unit MPR of the first embodiment, the modulation unit MPS includes a plurality of dots arranged in a matrix, and diffracts the light incident on the modulation unit MPS and outputs the diffracted light.

In this embodiment, the lights LR, LG, and LB emitted from the light emitting optical systems 51R, 51G, and 51B are guided to the phase modulation element 54S by the light guiding optical system 155, and are phase modulated, as in the first embodiment. The light is incident on element 54S. For this reason, below, with reference to FIG. 2, the incidence of these lights LR, LG, and LB on the phase modulation element 54S will be explained. In this embodiment, the power supplied to the light sources 52R, 52G, and 52B is adjusted so that each of the light sources 52R, 52G, and 52B emits laser light alternately, and the light emitting optical system 51R, 51G, and 51B alternately emits laser light. Lights LR, LG, and LB are emitted. That is, when the first light emitting optical system 51R emits the light LR, the second light emitting optical system 51G and the third light emitting optical system 51B do not emit the light LG and LB, and the second light emitting optical system 51G emits the light LR. When the light is emitted, the first light emitting optical system 51R and the third light emitting optical system 51B do not emit the light LR and LB, and when the third light emitting optical system 51B is emitting the light LB, the first light emitting optical system 51R and the third light emitting optical system 51B do not emit the light LB. The system 51R and the second light emitting optical system 51G do not emit the lights LR and LG. Then, the emission of laser light from each of the light sources 52R, 52G, and 52B is sequentially switched, and the emission of light LR, LG, and LB from each of the light emitting optical systems 51R, 51G, and 51B is sequentially switched. Therefore, the lights LR, LG, and LB having mutually different wavelength bands emitted from the light emitting optical systems 51R, 51G, and 51B are sequentially incident on the phase modulation element 54S. The phase modulation element 54S sequentially emits light DLR, DLG, and DLB obtained by diffracting the incident light LR, LG, and LB. Note that in this embodiment, as in the first embodiment, the optical path length from the phase modulation element 54S to the first light source 52R is longer than the optical path length from the phase modulation element 54S to the second light source 52G. The optical path length from the element 54S to the second light source 52G is longer than the optical path length from the phase modulation element 54S to the third light source 52B.

FIG. 7 shows an incident spot SR that is an area that is irradiated with red light LR, an incident spot SG that is an area that is irradiated with green light LG, and an incident spot that is an area that is irradiated with blue light LB. SB is shown. In addition, in FIG. 7, the incident spot SR is shown by a solid line, the incident spot SG is shown by a broken line, and the incident spot SB is shown by a chain line. In this embodiment, as in the first embodiment, the shapes of the lights LR, LG, and LB from the light sources 52R, 52G, and 52B, which are semiconductor lasers, are not adjusted. The shapes of the incident spots SR, SG, and SB of LB are approximately elliptical. In this embodiment, the sizes of these generally elliptical incident spots SR, SG, and SB are such that they can each contain at least one modulation section MPS. Furthermore, these incident spots SR, SG, and SB overlap each other.

In this embodiment, the incident spot SR has a generally elliptical shape that is elongated in the horizontal direction, and the longitudinal direction and the vertical direction of the incident spot SR are non-parallel. Further, the incident spot SG has a generally elliptical shape that is elongated in the vertical direction, and the longitudinal direction and the horizontal direction of the incident spot SG are non-parallel. Further, the incident spot SB has a generally elliptical shape that is elongated in the vertical direction, and the longitudinal direction and the horizontal direction of the incident spot SB are non-parallel. Further, in this embodiment, the vertical width of the incident spot SR is smaller than the vertical width of the incident spot SG, and the vertical width of the incident spot SG is approximately the same as the vertical width of the incident spot SB. considered to be the same.

Next, the emission of light from the phase modulation element 54S of this embodiment will be explained. Specifically, a case where the vehicle headlamp 1 emits light having a low beam light distribution pattern PL will be described as an example.

In this embodiment, the phase modulation element 54S changes the phase modulation pattern in synchronization with the switching of laser light emission for each of the light sources 52R, 52G, and 52B as described above. Specifically, when the light LR from the light source 52R is incident on the phase modulation element 54S, the first light DLR emitted from the phase modulation element 54S has a phase modulation pattern corresponding to the light source 52R. Create a phase modulation pattern that produces red component light in the low beam light distribution pattern. Therefore, when the light LR from the light source 52R is incident on the phase modulation element 54S, the phase modulation element 54S emits the first light DLR that is the light of the red component of the low beam light distribution pattern. Further, when the light LG from the light source 52G is incident on the phase modulation element 54S, the second light DLG emitted from the phase modulation element 54S has a phase modulation pattern corresponding to the light source 52G and a low beam pattern. Create a phase modulation pattern that produces light with the green component of the light pattern. Therefore, when the light LG from the light source 52G is incident on the phase modulation element 54S, the phase modulation element 54S emits the second light DLG that is the light of the green component of the low beam light distribution pattern. Further, when the light LB from the light source 52B is incident on the phase modulation element 54S, the third light DLB emitted from the phase modulation element 54S has a phase modulation pattern corresponding to the light source 52B, and the third light DLB emitted from the phase modulation element 54S is a low beam pattern. Create a phase modulation pattern that produces blue component light. Therefore, when the light LB from the light source 52B is incident on the phase modulation element 54S, the phase modulation element 54S emits the third light DLB, which is light of the blue component of the low beam light distribution pattern.

In other words, by changing the phase modulation pattern according to the wavelength bands of the incident lights LR, LG, and LB in this way, the phase modulation element 54S changes the first light DLR, which is the light of the red component of the low beam, and the low beam. The second light DLG, which is green component light, and the third light DLB, which is blue component light of the low beam, are sequentially emitted. These lights DLR, DLG, and DLB are each emitted from the opening 36H of the cover 36 and are sequentially irradiated to the outside of the vehicle headlamp 1 via the front cover 12. At this time, the first light DLR, the second light DLG, and the third light DLB are irradiated at a focal position a predetermined distance away from the vehicle so that the areas irradiated with each light overlap with each other. . This focal position is, for example, a position 25 meters away from the vehicle. Note that the first light DLR, the second light DLG, and the third light DLB are irradiated so that the outlines of the regions to which the respective lights DLR, DLG, and DLB are irradiated generally match at this focal position. It is preferable. Further, in this embodiment, since the length of each emission time of the laser beams emitted from the light sources 52R, 52G, and 52B is approximately the same, the length of each emission time of the light DLR, DLG, and DLB is also approximately the same. It will be the same.

By the way, when light of different colors is repeatedly irradiated at a cycle shorter than the time resolution of human vision, the human can recognize that light that is a combination of the different colors is irradiated due to the afterimage effect. In this embodiment, if the time from when the first light source 52R emits a laser beam until when the first light source 52R emits a laser beam again is made shorter than the time resolution of human vision, the time of human vision The lights DLR, DLG, and DLB emitted from the phase modulation element 54S are repeatedly irradiated with a cycle shorter than the resolution, and the red light DLR, the green light DLG, and the blue light DLB are combined by an afterimage effect. As mentioned above, the length of the emission time of each of the lights DLR, DLG, and DLB is approximately the same, and the intensity of the laser light emitted from the light sources 52R, 52G, and 52B is the same as in the first embodiment. It is assumed to have a predetermined strength. Therefore, the color of the light that is combined due to the afterimage effect is the same white color as the light that is the combination of the lights DLR, DLG, and DLB in the first embodiment. In addition, the light distribution pattern of the light DLR, DLG, and DLB combined becomes the low beam light distribution pattern PL, so the light distribution pattern of the light combined the light DLR, DLG, and DLB due to the afterimage effect also becomes the low beam light distribution pattern. This becomes the light distribution pattern PL. In this way, the light of the low beam light distribution pattern PL is emitted from the vehicle headlamp 1.

The period of repeatedly emitting laser light from the light sources 52R, 52G, and 52B is preferably set to 1/15 seconds or less from the viewpoint of suppressing the perception of flickering of the combined light due to an afterimage effect. The temporal resolution of human vision is approximately 1/30 s. In the case of a vehicle lamp, if the period of light emission is approximately twice as long, the perception of flickering of the light can be suppressed. If this period is 1/30 seconds or less, it generally exceeds the temporal resolution of human vision. Therefore, the perception of flickering of light can be further suppressed. Further, from the viewpoint of further suppressing the perception of flickering of light, it is preferable that this period is 1/60 seconds or less.

In this embodiment, as described above, the vertical width H54 of the entrance surface of the phase modulation element 54S is larger than the horizontal width WS of the entrance surface. Furthermore, the sizes of the incident spots SR, SG, and SB on the phase modulation element 54S are set to be large enough to include at least one modulation section MPS, and at least some of the plurality of modulation sections MPS are arranged in parallel in the vertical direction. Ru. Therefore, similarly to the first embodiment, the vehicle headlamp 1 of this embodiment has a low beam light distribution pattern even when the incident spots SR, SG, and SB move in the vertical direction in response to vibrations of the vehicle. PL can be formed.

In addition, in this embodiment, as described above, the width in the vertical direction of the incident spot SR having the maximum optical path length with the corresponding light source is the largest width among the widths in the vertical direction of the other incident spots SG and SB. The following shall apply. Therefore, in the vehicle headlamp 1 of this embodiment, the vertical width H54 of the entrance surface of the phase modulation element 54S and the difference between the phase modulation element 54S and the light sources 52R, 52G, and 52B are similar to the first embodiment. Even without adjusting the optical path length of the phase modulating element 54S, it is possible to prevent a part of the incident spot SR, where the amplitude of vibration of the incident spot with respect to the phase modulating element 54S tends to become large, from protruding from the incident surface of the phase modulating element 54S.

Further, in this embodiment, the incident spot SR has a generally elliptical shape that is elongated in a specific direction, and the specific direction that is the longitudinal direction of the incident spot SR is non-parallel to the vertical direction that is the vertical direction. Therefore, the vehicle headlamp 1 of this embodiment is similar to the first embodiment, compared to the case where the vertical direction is parallel to the specific direction that is the longitudinal direction of the incident spot SR. When the incident spot SR vibrates in the vertical direction in response to vibrations, part of the incident spot SR can be prevented from protruding from the incident surface of the phase modulation element 54R.

Furthermore, in this embodiment, the number of modulation units MPS arranged in parallel in the vertical direction is greater than the number of modulation units MPS arranged in parallel in the horizontal direction. Therefore, as in the first embodiment, compared to the case where the number of modulation units MPS arranged in parallel in the vertical direction is smaller than the number of modulation units MPS arranged in parallel in the horizontal direction, the incident When the spots SR, SG, and SB vibrate in the vertical direction, the lights LR, LG, and LB from the light sources 52R, 52G, and 52B can be made easier to enter one of the modulation units MPG.

Further, in the vehicle headlamp 1 of the present embodiment, the phase modulation element that diffracts the lights LR, LG, and LB from the three light sources 52R, 52G, and 52B can be a common phase modulation element, so that parts The number of points can be reduced or the size can be reduced.

Note that the vehicle lamp according to the first aspect includes a light source and a phase modulation element having a plurality of modulation sections that diffracts the light from the light source to form a predetermined light distribution pattern. The vertical width of the light incident surface of the modulation element is larger than the horizontal width of the light incidence surface, and the size of the light incident spot on the phase modulation element includes at least one modulation part. There is no particular limitation on the size of the phase modulation element, as long as at least some of the plurality of modulation sections are arranged in parallel in the vertical direction of the phase modulation element. A vehicle lamp with such a configuration can prevent a part of the incident spot from protruding from the incident surface of the phase modulation element even when the incident spot vibrates in the vertical direction in response to vehicle vibration, resulting in improved energy efficiency. It is possible to suppress the decrease. Further, in this vehicle lamp, even when the incident spot vibrates in the vertical direction in response to vibrations of the vehicle, light can enter any modulation section, so that a predetermined light distribution pattern can be formed.

In addition, in the first to third embodiments as the first aspect, the vehicle headlamp 1 as the vehicle lamp emits a low beam, but the vehicle lamp as the first aspect emits a low beam. The light used is not limited to low beam. For example, the vehicle lamp may be one that emits high beams or may be one that emits light that forms an image. When the vehicle lamp emits a high beam, light of a high beam light distribution pattern PH, which is a light distribution pattern for night illumination shown in FIG. 5(B), is emitted. Note that in the high beam light distribution pattern PH in FIG. 5(B), the area PHA1 is the area where the light intensity is the highest, and the area PHA2 is the area where the light intensity is lower than the area PHA1. In other words, each of the phase modulation elements 54R, 54G, and 54B in the phase modulation element assembly 54 of the first embodiment diffracts light so that the combined light forms a light distribution pattern that includes the intensity distribution of the high beam. It is said that Further, each of the phase modulation elements 54R, 54G, and 54B of the second embodiment as the first aspect diffracts light so that the combined light forms a light distribution pattern including the intensity distribution of the high beam. be done. Further, the phase modulation element 54S of the third embodiment is configured to diffract light so that the combined light due to the afterimage effect forms a light distribution pattern including the intensity distribution of the high beam. Further, in the case where the vehicular lamp emits light constituting an image, the direction of the light emitted by the vehicular lamp and the position at which the vehicular lamp is attached to the vehicle are not particularly limited.

Further, in the first to third embodiments as the first aspect, the phase modulation elements 54R, 54G, 54B, and 54S are reflective phase modulation elements. However, as the phase modulation element, for example, an LCD (Liquid Crystal Display) which is a liquid crystal panel, a GLV (Grating Light Valve) in which a plurality of reflectors are formed on a silicon substrate, a diffraction grating, etc. may be used. The LCD is a transmissive phase modulation element. Similar to the above-mentioned LCOS, which is a reflective liquid crystal panel, this LCD controls the phase of light emitted from each dot by controlling the voltage applied between a pair of electrodes that sandwich the liquid crystal layer at each dot. The amount of change is adjusted, and the light distribution pattern of the emitted light can be made into a desired light distribution pattern. Note that this pair of electrodes are transparent electrodes. Further, GLV is a reflective phase modulation element. By electrically controlling the deflection of the reflector, the GLV diffracts and emits incident light, and can make the light distribution pattern of the emitted light into a desired light distribution pattern.

Further, in the first embodiment as the first aspect, the first phase modulation element 54R, the second phase modulation element 54G, and the third phase modulation element 54B of the phase modulation element assembly 54 are adjacent to each other in the horizontal direction and are parallel to each other. It had been. However, these phase modulation elements 54R, 54G, and 54B may be arranged in parallel in the vertical direction, or may be arranged in parallel in the vertical and horizontal directions.

Further, in the first embodiment as the first aspect and the third embodiment, the light guide optical system 155 included a reflection mirror 155m, a first optical element 155f, and a second optical element 155s. However, the light guiding optical system 155 only needs to guide the lights LR, LG, and LB emitted from the respective light emitting optical systems 51R, 51G, and 51B to the phase modulating element assembly 54 and the phase modulating element 54S, and It is not limited to the configuration of the embodiment or the third embodiment. For example, the light guiding optical system 155 does not need to include the reflecting mirror 155m. In such a case, the light LR emitted from the first light emitting optical system 51R is made incident on the first optical element 155f. Furthermore, in the first and third embodiments described above, a bandpass filter that transmits light in a predetermined wavelength band and reflects light in other wavelength bands is used in the first optical element 155f and the second optical element 155s. It's okay to be beaten.

Further, in the first embodiment as the first aspect and the third embodiment, the optical system unit 50 transmits the lights LR, LG, and LB emitted from the light emitting optical systems 51R, 51G, and 51B to the phase modulation element assembly 54 and the third embodiment. It was equipped with a light guide optical system 155 that guides the light to the phase modulation element 54S. However, the optical system unit 50 does not need to include the light guiding optical system 155. In this case, the light emitting optical systems 51R, 51G, and 51B are arranged so that these lights LR, LG, and LB are incident on the phase modulation element assembly 54 and the phase modulation element 54S.

Further, in the second embodiment as the first aspect, the first optical element 55f transmits the first light DLR and reflects the second light DLG, so that the first light DLR and the second light DLR are connected to each other. DLG, and the second optical element 55s transmits the first light DLR and the second light DLG combined by the first optical element 55f, and reflects the third light DLB. The optical DLR, the second optical DLG, and the third optical DLB were combined. However, for example, the third light DLB and the second light DLG are combined in the first optical element 55f, and the third light DLB and the second light DLG combined in the first optical element 55f are combined in the second optical element 55s. The optical DLG and the first optical DLR may be combined. In this case, in the second embodiment, the first light source 52R, first collimating lens 53R, and first phase modulating element 54R, and the third light source 52B, third collimating lens 53B, and third phase modulating element 54B The positions are swapped. Further, in the second embodiment, a bandpass filter that transmits light in a predetermined wavelength band and reflects light in other wavelength bands may be used for the first optical element 55f and the second optical element 55s. In addition, in the second embodiment, the combining optical system 55 only needs to combine the lights DLR, DLG, and DLB emitted from the respective phase modulation elements 54R, 54G, and 54B. Not limited.

Further, in the second embodiment as the first aspect, the optical system unit 50 was equipped with a combining optical system 55 that combines the first light DLR, the second light DLG, and the third light DLB. However, the optical system unit 50 does not need to include the combining optical system 55. In this case, similarly to the first embodiment, each of the phase modulation elements 54R, 54G, and 54B is arranged so that the lights DLR, DLG, and DLB emitted from the respective phase modulation elements 54R, 54G, and 54B are combined. , diffracts the incident lights LR, LG, and LB.

Further, in the first embodiment as the first aspect, the optical system unit 50 did not include a combining optical system that combines the first light DLR, the second light DLG, and the third light DLB. However, the optical system unit 50 of the first embodiment may include a synthetic optical system similarly to the second embodiment.

Further, in the second embodiment as the first aspect, the optical system unit 50 is a light guide that guides the lights LR, LG, and LB emitted from the light emitting optical systems 51R, 51G, and 51B to the phase modulation elements 54R, 54G, and 54B. It did not have an optical system. However, the optical system unit 50 of the second embodiment may be provided with a light guide optical system similarly to the first embodiment.

Further, in the first to third embodiments as the first aspect, the lamp unit 20 did not include an imaging lens system including an imaging lens. However, the lamp unit 20 may include an imaging lens system, and the light emitted from the optical system unit 50 may be emitted through this imaging lens system. With such a configuration, the light distribution pattern of the emitted light can be easily made into a wider light distribution pattern. Note that "wide" here means that it is wide when comparing light distribution patterns formed on a vertical plane a predetermined distance away from the vehicle.

Furthermore, in the first to third embodiments as the first aspect, the incident spots SR, SG, and SB were generally elliptical. However, the shapes of the incident spots SR, SG, and SB are not particularly limited, and may be circular, for example.

Further, in the first to third embodiments as the first form, the shapes of the phase modulation elements 54R, 54G, 54B, and 54S are generally rectangular, and the incident surfaces of each are also generally rectangular. However, the shape of the entrance surface of the phase modulation elements 54R, 54G, 54B, and 54S may be any shape as long as the width in the vertical direction is larger than the width in the horizontal direction.

Further, in the first embodiment as the first form, all three phase modulation elements 54R, 54G, and 54B are integrally formed. However, from the viewpoint of reducing the number of parts, if at least one phase modulation element among the plurality of phase modulation elements is connected to at least one other phase modulation element and formed integrally with this other phase modulation element, good.

Further, in the third embodiment as the first form, the three light sources 52R, 52G, and 52B alternately emit light. However, from the viewpoint of reducing the number of parts and downsizing, it is sufficient that at least two light sources emit light alternately. In this case, the light emitted from the phase modulation element into which the light emitted from at least two light sources enters is combined by the afterimage effect, and the combined light and the light emitted from the other phase modulation element are combined by this afterimage effect. Then, light with a predetermined light distribution pattern is irradiated.

Further, in the first embodiment as the first form, three light sources 52R, 52G, 52B that emit laser beams in different wavelength bands and three phase modulation elements 54R, 54G, 54B are integrated into a single unit. The optical system unit 50 including two phase modulating element aggregates 54 has been described as an example. In addition, in the second embodiment as the first form, three light sources 52R, 52G, 52B that emit laser beams in different wavelength bands, and three phase modulations that correspond one-to-one to the light sources 52R, 52G, 52B. The optical system unit 50 including the elements 54R, 54G, and 54B has been described as an example. Further, in the third embodiment as the first form, an optical system unit 50 including three light sources 52R, 52G, and 52B that emit laser beams of mutually different wavelength bands and one phase modulation element 54S is taken as an example. explained. However, the optical system unit only needs to include at least one light source and a phase modulation element corresponding to this light source. For example, the optical system unit may include a light source that emits white laser light and a phase modulation element that diffracts and emits the white laser light that is emitted from the light source. Further, when the optical system unit includes a plurality of light sources and phase modulation elements, at least one light source only needs to correspond to each phase modulation element. For example, light that is a combination of lights emitted from a plurality of light sources may be input to one phase modulation element.

(Fourth embodiment)
Next, a fourth embodiment as a second aspect of the present invention will be described. Note that components that are the same or similar to those in the first embodiment are given the same reference numerals and redundant explanations will be omitted, unless otherwise specified. In the optical system unit 50 of this embodiment, the configuration of the phase modulation element assembly 54 is different from the configuration of the phase modulation element assembly 54 of the first embodiment.

FIG. 8 is a diagram similar to FIG. 2 showing an optical system unit in a fourth embodiment as a second aspect of the present invention. As shown in FIG. 8, the phase modulation element assembly 54 of this embodiment is arranged so that the entrance surface EF into which light enters is inclined at approximately 45 degrees with respect to the vertical direction, and the light is emitted from the light guide optical system 155. Lights LR, LG, and LB are incident on the entrance plane EF. Note that the angle of the entrance plane EF with respect to the vertical direction is not particularly limited, and for example, the phase modulation element assembly 54 may be arranged so that the entrance plane EF is approximately parallel to the vertical direction. The light guide optical system 155 of this embodiment emits the lights LR, LG, and LB in parallel in the front-back direction without multiplexing them, and these lights LR, LG, and LB enter the phase modulation element assembly 54 . In this embodiment, the optical path length from this phase modulation element assembly 54 to the first light source 52R of the first light emitting optical system 51R is the same as the optical path length from the phase modulation element assembly 54 to the second light source 52G of the second light emitting optical system 51G. longer than the optical path length. Further, the optical path length from the phase modulating element assembly 54 to the second light source 52G of the second light emitting optical system 51G is longer than the optical path length from the phase modulating element assembly 54 to the third light source 52B of the third light emitting optical system 51B. long.

Similar to the phase modulation element assembly 54 of the first embodiment, the phase modulation element assembly 54 performs phase modulation that diffracts the light LR from the first light emitting optical system 51R and makes the light LR a predetermined light distribution pattern. a phase modulation element that diffracts the light LG from the second light emitting optical system 51G and makes the light LG into a predetermined light distribution pattern; and a phase modulation element that diffracts the light LB from the third light emitting optical system 51B and makes the light LB and a phase modulation element that has a predetermined light distribution pattern. These three phase modulation elements are arranged in one direction, and the entrance surface EF of the phase modulation element assembly 54 is constituted by the light entrance surface of these phase modulation elements. Further, these phase modulation elements are reflection type LCOS, similar to the phase modulation element of the first embodiment.

Next, the configuration of the phase modulation element assembly 54 of this embodiment will be explained in detail.

FIG. 9 is a front view of the phase modulation element assembly shown in FIG. 8. Note that FIG. 9 is a front view of the phase modulation element assembly 54 seen from the side of the entrance plane EF where light enters, and the phase modulation element assembly 54 is schematically shown in FIG. The phase modulation element assembly 54 of this embodiment is formed into a generally rectangular shape elongated in the vertical direction when viewed from the front, and the entire area when viewed from the front is the entrance plane EF. Therefore, it can be understood that the entrance surface EF of the phase modulation element assembly 54 is formed into a generally rectangular shape that is elongated in the vertical direction. Hereinafter, in this specification, when the phase modulation element assembly 54 is viewed from the front, a direction parallel to the horizontal direction will be referred to as a horizontal direction, and a direction perpendicular to this horizontal direction will be referred to as a vertical direction. Therefore, the horizontal direction is a direction parallel to the horizontal direction, and the vertical direction is a direction parallel to the direction in which the vertical direction is projected onto the entrance plane EF, and is a direction parallel to the vertical direction in this front view.

The phase modulating element assembly 54 of this embodiment includes a first phase modulating element 54R corresponding to the first light emitting optical system 51R, a second phase modulating element 54G corresponding to the second light emitting optical system 51G, and a third light emitting optical system 54R. It has a third phase modulation element 54B corresponding to the system 51B. The first phase modulation element 54R, the second phase modulation element 54G, and the third phase modulation element 54B are arranged adjacently in parallel in the vertical direction. A three-phase modulation element 54B is connected thereto. In other words, the phase modulation element assembly has a configuration in which these phase modulation elements 54R, 54G, and 54B are integrally formed. A drive circuit 60R is electrically connected to this phase modulation element assembly 54. The drive circuit 60R includes a scanning line drive circuit connected to the horizontal side of the phase modulation element assembly 54 and a data line drive circuit connected to one side of the phase modulation element assembly 54 in the vertical direction. Power is supplied to each of the phase modulation elements 54R, 54G, and 54B constituting the phase modulation element assembly 54 via this drive circuit 60R.

The lateral width of the first phase modulation element 54R, the lateral width of the second phase modulation element 54G, and the lateral width of the third phase modulation element 54B are the lateral width W54 of the phase modulation element assembly 54. is considered to be the same as The vertical width of the first phase modulating element 54R, the vertical width of the second phase modulating element 54G, and the vertical width of the third phase modulating element 54B are the horizontal width W54 of the phase modulating element assembly 54. It is considered to be smaller than That is, these phase modulation elements 54R, 54G, and 54B are formed into a generally rectangular shape that is elongated in the horizontal direction. As described above, the entire area of the phase modulation element assembly 54 in front view is defined as the entrance plane EF, and the entrance plane EF of the phase modulation element assembly 54 is defined by the light incidence plane of these phase modulation elements 54R, 54G, and 54B. Because of this configuration, each of the light incident surfaces of the phase modulation elements 54R, 54G, and 54B is also formed into a generally rectangular shape that is elongated in the horizontal direction. Further, the longitudinal direction of each of these phase modulation elements 54R, 54G, and 54B is generally perpendicular to the longitudinal direction in which these phase modulation elements 54R, 54G, and 54B are arranged in parallel. Therefore, the longitudinal direction of each of the light incident surfaces of the phase modulation elements 54R, 54G, and 54B is substantially perpendicular to the longitudinal direction. In this embodiment, the vertical width of the first phase modulating element 54R, the vertical width of the second phase modulating element 54G, and the vertical width of the third phase modulating element 54B are approximately the same. Therefore, the vertical widths of the light incident surfaces of the phase modulation elements 54R, 54G, and 54B are approximately the same.

A plurality of modulation units MPR arranged in a matrix are formed in the first phase modulation element 54R. A plurality of modulation sections MPG arranged in a matrix are formed in the second phase modulation element 54G, and a plurality of modulation sections MPB arranged in a matrix are formed in the third phase modulation element 54B. In this embodiment, these modulation units MPR, MPG, and MPB are squares of the same size. Therefore, the number of modulation units MPR arranged in parallel in the longitudinal direction of the entrance surface of the first phase modulation element 54R is smaller than the number of modulation parts MPR arranged in parallel in the direction perpendicular to the longitudinal direction of the entrance surface of the phase modulation element 54R. There are also many. Further, the number of modulation units MPG arranged in parallel in the longitudinal direction of the entrance surface of the second phase modulation element 54G is the number of modulation units MPG arranged in parallel in the direction perpendicular to the longitudinal direction of the entrance surface of the second phase modulation element 54G. The number of modulators MPB arranged in parallel in the longitudinal direction of the entrance surface of the third phase modulator 54B is greater than the number of modulators MPB arranged in parallel in the longitudinal direction of the entrance surface of the third phase modulator 54B. more than the number of Each of the modulation units MPR, MPG, and MPB includes a plurality of dots arranged in a matrix, and diffracts and emits light incident on the modulation units MPR, MPG, and MPB.

The red light LR emitted from the light guide optical system 155 enters the first phase modulation element 54R, and the first phase modulation element 54R emits the first light DLR obtained by diffracting the light LR. The green light LG emitted from the light guide optical system 155 enters the second phase modulation element 54G, and the second phase modulation element 54G emits second light DLG obtained by diffracting this light LG. The blue light LB emitted from the light guide optical system 155 enters the third phase modulation element 54B, and the third phase modulation element 54B emits third light DLB which is the diffracted light LB.

FIG. 9 shows an incident spot SR that is an area that is irradiated with red light LR, an incident spot SG that is an area that is irradiated with green light LG, and an incident spot that is an area that is irradiated with blue light LB. SB is shown. In this embodiment, as described above, the light sources 52R, 52G, and 52B are semiconductor lasers, so the laser beams emitted from the light sources 52R, 52G, and 52B propagate while expanding in an approximately elliptical shape. Furthermore, although the fast axis direction and slow axis direction of the laser beams emitted from these light sources 52R, 52G, and 52B are collimated by collimating lenses 53R, 53G, and 53B, the shapes of these laser beams are not adjusted. The lights LR, LG, and LB whose shapes have not been adjusted in this way are emitted from the light emitting optical systems 51R, 51G, and 51B, and are incident on the phase modulation element assembly 54 via the light guiding optical system 155, respectively. In this embodiment, since the shapes of these lights LR, LG, and LB are not adjusted in the light guide optical system 155, the shapes of the incident spots SR, SG, and SB are each approximately elliptical.

Further, in this embodiment, the size of the approximately elliptical incident spot SR is set to be large enough to include at least one modulation section MPR, and the long axis LAR of this incident spot SR is the incident spot of the first phase modulating element 54R. It is generally parallel to the lateral direction, which is the longitudinal direction of the surface. In other words, the incident spot SR has a generally elliptical shape that is elongated in the horizontal direction, and the longitudinal direction of the incident spot SR is not perpendicular to the longitudinal direction of the incident surface of the first phase modulation element 54R. Further, the size of the approximately elliptical incident spot SG is set to be large enough to include at least one modulation section MPG, and the long axis LAG of this incident spot SG is in the longitudinal direction of the incident surface of the second phase modulation element 54G. It is assumed to be approximately parallel to a certain horizontal direction. In other words, the incident spot SG has a generally elliptical shape that is elongated in the horizontal direction, and the longitudinal direction of the incident spot SG is not perpendicular to the longitudinal direction of the incident surface of the second phase modulation element 54G. Further, the size of the approximately elliptical incident spot SB is set to be large enough to include at least one modulation section MPB, and the long axis LAB of this incident spot SB is in the longitudinal direction of the incident surface of the third phase modulation element 54B. It is assumed to be approximately parallel to a certain horizontal direction. In other words, the incident spot SB has a generally elliptical shape that is elongated in the horizontal direction, and the longitudinal direction of the incident spot SB is not perpendicular to the longitudinal direction of the incident surface of the third phase modulation element 54B.

In addition, in this embodiment, the width in the vertical direction, which is a direction perpendicular to the longitudinal direction of the incident spot SR, the width in the vertical direction, which is a direction perpendicular to the longitudinal direction of the incident spot SG, and the longitudinal direction of the incident spot SB, The width in the vertical direction is approximately the same. Further, the width of the incident spot SR in the lateral direction in the longitudinal direction, the width in the lateral direction in the longitudinal direction of the incident spot SG, and the lateral width in the longitudinal direction of the incident spot SB are approximately the same. Note that the widths of these incident spots SR, SG, and SB may be different from each other.

In this embodiment, the same phase modulation pattern is formed in each modulation section MPR in the first phase modulation element 54R of the phase modulation element assembly 54. Furthermore, the same phase modulation pattern is formed in each modulation section MPG in the second phase modulation element 54G, and the same phase modulation pattern is formed in each modulation section MPB in the third phase modulation element 54B. Note that in this specification, a phase modulation pattern refers to a pattern that modulates the phase of incident light. In this embodiment, the phase modulation pattern is a pattern of the refractive index of the liquid crystal layer 66 in each dot DT, and is also a pattern of voltage applied between the electrode 64 and the transparent electrode 67 corresponding to each dot DT. It can be understood. By adjusting this phase modulation pattern, the light distribution pattern of the emitted light can be made into a desired light distribution pattern. In this embodiment, the phase modulation patterns in the modulation units MPR, MPG, and MPB are different from each other.

Specifically, in this embodiment, as in the first embodiment, each phase modulation pattern in the modulation units MPR, MPG, and MPB is composed of the first light DLR emitted from the first phase modulation element 54R and the second light DLR. The light obtained by combining the second light DLG emitted from the phase modulation element 54G and the third light DLB emitted from the third phase modulation element 54B becomes the low beam light distribution pattern PL shown in FIG. 5(A). This is a phase modulation pattern that diffracts the lights LR, LG, and LB, respectively. In other words, the phase modulation elements 54R, 54G, and 54B of the phase modulation element assembly 54 have a low beam light distribution pattern in which the light DLR, DLG, and DLB emitted from the phase modulation elements 54R, 54G, and 54B are combined. The incident lights LR, LG, and LB are each diffracted so as to become PL. This light distribution pattern also includes intensity distribution. Therefore, in this embodiment, the first light DLR emitted from the first phase modulation element 54R overlaps with the low beam light distribution pattern PL and has an intensity distribution based on the intensity distribution of the low beam light distribution pattern PL. . The second light DLG emitted from the second phase modulation element 54G overlaps the low beam light distribution pattern PL and has an intensity distribution based on the intensity distribution of the low beam light distribution pattern PL. The third light DLB emitted from the third phase modulation element 54B overlaps the low beam light distribution pattern PL and has an intensity distribution based on the intensity distribution of the low beam light distribution pattern PL. As described above, these phase modulation elements 54R, 54G, and 54B each have a plurality of modulation sections MPR, MPG, and MPB that form the same phase modulation pattern. The lights LR, LG, and LB are each diffracted so as to form a light distribution pattern. Note that these phase modulation elements 54R, 54G, and 54B are arranged so that the outline of the light distribution pattern of the light DLR, DLG, and DLB emitted from the phase modulation elements 54R, 54G, and 54B matches the outline of the light distribution pattern PL of the low beam. Preferably, the incident lights LR, LG, and LB are each diffracted. In this way, the first phase modulating element 54R emits the red component light DLR of the low beam light distribution pattern PL, the second phase modulating element 54G emits the green component light DLG of the low beam light distribution pattern PL, and the third phase modulating element 54G emits the green component light DLG of the low beam light distribution pattern PL. The phase modulation element 54B emits blue component light DLB of the low beam light distribution pattern PL.

These lights DLR, DLG, and DLB emitted from the phase modulation element assembly 54 are irradiated to the outside of the vehicle headlamp 1 via the front cover 12, respectively. At this time, these lights DLR, DLG, and DLB are irradiated at a focal position a predetermined distance away from the vehicle so that the areas irradiated with each light overlap with each other. This focal position is, for example, a position 25 meters away from the vehicle. The combined light of these lights DLR, DLG, and DLB becomes a low beam light distribution pattern PL, so the irradiated light becomes a low beam. Note that it is preferable that these lights DLR, DLG, and DLB are irradiated so that the outer shapes of their respective light distribution patterns approximately match each other at this focal position.

Here, in the above-mentioned Patent Document 1, a semiconductor laser is mentioned as a light source, for example. Since the laser light emitted from the semiconductor laser propagates while spreading in a generally elliptical shape, if the shape of the laser light is not adjusted, the incident spot of the laser light will have a generally elliptical shape that is elongated in a specific direction. On the other hand, the hologram element is generally rectangular, which is different from the shape of the incident spot of the laser beam. Therefore, when the laser light emitted from the semiconductor laser is incident on the entire hologram element, a part of the laser light emitted from the semiconductor laser is not irradiated to the hologram element, resulting in a decrease in energy efficiency. There is a demand to suppress this. To meet this request, for example, it may be possible to adjust the shape of the laser beam so that the shape of the incident spot corresponds to the shape of the hologram element. However, in such a case, since an optical element is used to adjust the shape of the laser beam, there is a risk that the vehicle lamp will become larger.

Therefore, the vehicle headlamp 1 of this embodiment as a second aspect includes light sources 52R, 52G, and 52B that emit light, a first phase modulation element 54R, a second phase modulation element 54G, and a third phase modulation element. and a phase modulation element assembly 54 having an element 54B. The first phase modulation element 54R includes a plurality of modulation units MPR that diffracts the light LR from the first light source 52R to form a predetermined light distribution pattern. The second phase modulation element 54G includes a plurality of modulation units MPG that diffracts the light LG from the second light source 52G to form a predetermined light distribution pattern. The third phase modulation element 54B includes a plurality of modulation units MPB that diffracts the light LB from the third light source 52B to form a predetermined light distribution pattern. The entrance surface of the first phase modulation element 54R, the entrance surface of the second phase modulation element 54G, and the entrance surface of the third phase modulation element 54B are each generally rectangular in shape, elongated in the lateral direction. The incident spot SR of the light LR on the first phase modulating element 54R, the incident spot SG of the light LG on the second phase modulating element 54G, and the incident spot SB of the light LB on the third phase modulating element 54B are each elongated in the horizontal direction. It has a roughly elliptical shape. The size of the incident spot SR is set to be large enough to include at least one modulation section MPR, the size of the incident spot SG is set to be large enough to include at least one modulation section MPG, and the size of the incident spot SB is set to be large enough to include at least one modulation section MPG. The size is such that it can include at least one modulation section MPB. The longitudinal direction of the incident surface of the first phase modulation element 54R and the longitudinal direction of the incident spot SR are non-perpendicular, and the longitudinal direction of the incident surface of the second phase modulation element 54G and the longitudinal direction of the incident spot SG are non-perpendicular. The longitudinal direction of the incident surface of the third phase modulation element 54B and the longitudinal direction of the incident spot SB are made non-perpendicular.

In the vehicle headlamp 1 of the present embodiment as the second aspect, the light LR from the first light source 52R can enter at least one modulation section MPR, and the light LR from the second light source 52G can enter at least one modulation section MPG. The light LG from the third light source 52B may be incident on at least one modulation unit MPB. Therefore, the low beam light distribution pattern PL can be formed by these modulators MPR, MPG, and MPB. Further, in the vehicle headlamp 1 of the present embodiment, as described above, the entrance surface of the first phase modulation element 54R, the entrance surface of the second phase modulation element 54G, and the entrance surface of the third phase modulation element 54B are , each of which has a generally rectangular shape that is elongated in the horizontal direction. The incident spot SR, the incident spot SG, and the incident spot SG each have a substantially elliptical shape that is elongated in the horizontal direction. The longitudinal direction of the incident surface of the first phase modulation element 54R and the longitudinal direction of the incident spot SR are non-perpendicular, and the longitudinal direction of the incident surface of the second phase modulation element 54G and the longitudinal direction of the incident spot SG are non-perpendicular. The longitudinal direction of the incident surface of the third phase modulation element 54B and the longitudinal direction of the incident spot SB are made non-perpendicular. Therefore, in the vehicle headlamp 1 of the present embodiment, compared to the case where the longitudinal direction of the incident surface of the first phase modulating element 54R and the longitudinal direction of the incident spot SR are perpendicular, Even without adjusting the shape of the light LR, it is possible to prevent a part of the incident spot SR from protruding from the incident surface of the first phase modulation element 54R. Furthermore, in the vehicle headlamp 1 of the present embodiment, compared to the case where the longitudinal direction of the incident surface of the second phase modulation element 54G and the longitudinal direction of the incident spot SG are perpendicular, the light emitted from the second light source 52G is Even without adjusting the shape of the light LG, it is possible to prevent a part of the incident spot SG from protruding from the incident surface of the second phase modulating element 54G, and the longitudinal direction of the incident surface of the third phase modulating element 54B and the incident spot can be suppressed. Compared to the case where the longitudinal direction of SB is perpendicular, a part of the incident spot SB protrudes from the incident surface of the third phase modulation element 54B without adjusting the shape of the light LB from the third light source 52B. can be suppressed. Therefore, the vehicle headlamp 1 of this embodiment can suppress increase in size while suppressing a decrease in energy efficiency.

In addition, in the vehicle headlamp 1 of the present embodiment as a second aspect, the longitudinal direction of the incident surface of the first phase modulation element 54R and the longitudinal direction of the incident spot SR are generally parallel to each other, and the second phase modulation The longitudinal direction of the incident surface of the element 54G and the longitudinal direction of the incident spot SG are generally parallel, and the longitudinal direction of the incident surface of the third phase modulating element 54B and the longitudinal direction of the incident spot SB are generally parallel. Therefore, the vehicle headlamp 1 of this embodiment can further suppress part of the incident spot SR from protruding from the incident surface of the first phase modulation element 54R. Moreover, it is possible to further suppress a part of the incident spot SG from protruding from the incident surface of the second phase modulation element 54G, and it is possible to further suppress a part of the incident spot SB from protruding from the incident surface of the third phase modulation element 54B. obtain.

Further, the vehicle headlamp 1 of the present embodiment as a second aspect has a plurality of light sources 52R, 52G, 52B, and the phase modulation element assembly 54 receives the light LR from the first light source 52R. a second phase modulation element 54G into which light LG from a second light source 52G is incident, and a third phase modulation element 54B into which light LB from a third light source 52B is incident. That is, these phase modulation elements 54R, 54G, and 54B of the phase modulation element assembly 54 are provided for each light source 52R, 52G, and 52B. The phase modulation element assembly 54 has a configuration in which a first phase modulation element 54R and a third phase modulation element 54B are connected to a second phase modulation element 54G, and these phase modulation elements 54R, 54G, and 54B are integrally formed. ing. Therefore, in the vehicle headlamp 1 of this embodiment, the number of parts can be reduced compared to a case where these phase modulation elements 54R, 54G, and 54B are provided separately.

(Fifth embodiment)
Next, a fifth embodiment as a second aspect of the present invention will be described in detail with reference to FIGS. 10 and 11. Note that components that are the same or equivalent to those in the fourth embodiment are given the same reference numerals and redundant explanations will be omitted, unless otherwise specified.

FIG. 10 is a diagram schematically showing an optical system unit in a fifth embodiment as a second aspect of the present invention. Note that FIG. 10 is a view of the optical system unit 50 seen from the opening 36H side of the cover 36, which is the front side. In FIG. 10, the heat sink 30, the cover 36, and the phase modulation element assembly are The description of the light DLR, DLG, DLB, etc. emitted from 54 is omitted. As shown in FIG. 10, the optical system unit 50 of this embodiment differs from the optical system unit 50 of the fourth embodiment mainly in that it does not include a light guide optical system 155.

In the optical system unit 50 of this embodiment, similarly to the fourth embodiment, the phase modulation element assembly 54 is arranged such that the entrance plane EF into which light is incident is inclined at approximately 45 degrees with respect to the vertical direction, and the phase modulation element assembly 54 is arranged such that the entrance plane EF on which light enters is inclined at approximately 45 degrees with respect to the vertical direction. The optical systems 51R, 51G, and 51B are arranged below the phase modulation element assembly 54. Each of the lights LR, LG, and LB emitted from the light emitting optical systems 51R, 51G, and 51B is directly incident on the phase modulation element assembly 54. In this embodiment, the light sources 52R, 52G, and 52B are arranged in parallel in the left-right direction, and the light emitting optical systems 51R, 51G, and 51B including the light sources 52R, 52G, and 52B are arranged in parallel in the left-right direction. The lights LR, LG, and LB from the light emitting optical systems 51R, 51G, and 51B arranged in parallel in this manner enter the phase modulation element assembly 54 in a state in which they are arranged in parallel in the left-right direction.

FIG. 11 is a front view of the phase modulation element assembly shown in FIG. 10. Note that FIG. 11 is a front view of the phase modulation element assembly 54 seen from the side of the entrance surface EF where light enters, and the phase modulation element assembly 54 is schematically shown in FIG. 11. As shown in FIG. 11, the phase modulation element assembly 54 of this embodiment is different from the phase modulation element assembly 54 of the fourth embodiment in that the three phase modulation elements 54R, 54G, and 54B are arranged in adjacent parallel directions. It is different from the body 54.

Specifically, the phase modulation element assembly 54 of this embodiment is formed into a generally rectangular shape that is elongated in the horizontal direction, which is the left-right direction, when viewed from the front. The three phase modulation elements 54R, 54G, and 54B are arranged adjacent to each other in the horizontal direction, and the first phase modulation element 54R and the third phase modulation element 54B are connected to the second phase modulation element 54G. These phase modulation elements 54R, 54G, and 54B each have a generally rectangular shape that is long in the horizontal direction, and the incident spots SR, SG, and SB each have a generally long elliptical shape that is long in the horizontal direction. It is said that Therefore, the longitudinal direction of the incident surface of the first phase modulating element 54R and the longitudinal direction of the incident spot SR are non-perpendicular, and the longitudinal direction of the incident surface of the second phase modulating element 54G and the longitudinal direction of the incident spot SG are not perpendicular to each other. The longitudinal direction of the incident surface of the third phase modulating element 54B and the longitudinal direction of the incident spot SB are non-perpendicular. Further, the longitudinal direction of the incident surface of these phase modulation elements 54R, 54G, 54B is generally parallel to the lateral direction, which is the direction in which these phase modulation elements 54R, 54G, 54B are arranged in parallel.

In the vehicle headlamp 1 of the present embodiment as the second aspect, the longitudinal direction of the incident surface of the first phase modulating element 54R and the longitudinal direction of the incident spot SR are perpendicular, similarly to the fourth embodiment. Compared to the case where the light LR from the first light source 52R is not adjusted, part of the incident spot SR can be prevented from protruding from the incident surface of the first phase modulation element 54R. Furthermore, in the vehicle headlamp 1 of the present embodiment, compared to the case where the longitudinal direction of the incident surface of the second phase modulation element 54G and the longitudinal direction of the incident spot SG are perpendicular, the light emitted from the second light source 52G is Even without adjusting the shape of the light LG, it is possible to prevent a part of the incident spot SG from protruding from the incident surface of the second phase modulating element 54G, and the longitudinal direction of the incident surface of the third phase modulating element 54B and the incident spot can be suppressed. Compared to the case where the longitudinal direction of SB is perpendicular, a part of the incident spot SB protrudes from the incident surface of the third phase modulation element 54B without adjusting the shape of the light LB from the third light source 52B. can be suppressed. Therefore, the vehicle headlamp 1 of this embodiment can suppress increase in size while suppressing a decrease in energy efficiency.

Further, in the vehicle headlamp 1 of this embodiment as the second aspect, the three phase modulation elements 54R, 54G, and 54B are arranged adjacent to each other in the horizontal direction, which is the left-right direction. Further, the light sources 52R, 52G, 52B are arranged in parallel in the left and right direction corresponding to the phase modulation elements 54R, 54G, 54B, and the light from the light sources 52R, 52G, 52B is phase modulated without passing through the light guide optical system 155. The light is incident on the element assembly 54. Therefore, the vehicle headlamp 1 of this embodiment can have a simpler configuration than the case where the light guiding optical system 155 is provided. Further, in the vehicle headlamp 1 of this embodiment, the longitudinal direction of the entrance plane of the phase modulating elements 54R, 54G, 54B is approximately the same as the lateral direction, which is the direction in which these phase modulating elements 54R, 54G, 54B are arranged in parallel. considered to be parallel. For this reason, compared to the case where the longitudinal direction of each of the incident surfaces of the phase modulation elements 54R, 54G, 54B that are arranged adjacent to each other in parallel is perpendicular to the direction in which these phase modulation elements 54R, 54G, 54B are arranged in parallel. , the distance between the centers of the first phase modulation element 54R and the second phase modulation element 54G and the distance between the centers of the second phase modulation element 54G and the third phase modulation element 54B become longer. For this reason, compared to the case where the longitudinal direction of each of the incident surfaces of the phase modulation elements 54R, 54G, 54B that are arranged adjacent to each other in parallel is perpendicular to the direction in which these phase modulation elements 54R, 54G, 54B are arranged in parallel. , the distance between the first light source 52R and the second light source 52G and the distance between the second light source 52G and the third light source 52B can be increased. Therefore, in the vehicle headlamp 1 of this embodiment, the phase modulation elements 54R, 54G, 54B are arranged in parallel with each other in the longitudinal direction of the entrance plane of the phase modulation elements 54R, 54G, 54B that are arranged in parallel. The light sources 52R, 52G, and 52B can be made larger than in the case where the direction is perpendicular to the light source. Moreover, the vehicle headlamp 1 of this embodiment can suppress interference between the adjacent first light source 52R and second light source 52G, and between the second light source 52G and third light source 52B. Further, in the vehicle headlamp 1 of this embodiment, these light sources 52R, 52G, and 52B are overheated due to thermal interference between the adjacent first light source 52R and second light source 52G and between the second light source 52G and third light source 52B. It can suppress heating.

(Sixth embodiment)
Next, a sixth embodiment as a second aspect of the present invention will be described in detail with reference to FIG. 12. Note that components that are the same or equivalent to those in the fourth embodiment are given the same reference numerals and redundant explanations will be omitted, unless otherwise specified.

FIG. 12 is a diagram similar to FIG. 2 showing an optical system unit in a sixth embodiment as a second aspect of the present invention. Note that in FIG. 12, the description of the heat sink 30, cover 36, etc. is omitted for easy understanding. As shown in FIG. 12, the optical system unit 50 of this embodiment is mainly different from the optical system unit 50 of the fourth embodiment in that it includes one phase modulation element 54S instead of the phase modulation element assembly 54. different.

In this embodiment, the configuration of the phase modulation element 54S is the same as that of the phase modulation elements 54R, 54G, and 54B of the fourth embodiment. The phase modulation element 54S is formed into a generally rectangular shape that is elongated in the lateral direction when viewed from the front from the side of the entrance surface EFS where light enters. Therefore, the width in the horizontal direction of the entrance surface EFS of the phase modulation element 54S is made larger than the width in the vertical direction of the entrance surface EFS of the phase modulation element 54S. The phase modulation element 54S has a plurality of modulation parts arranged in a matrix, and the number of modulation parts arranged in parallel in the longitudinal direction of the entrance surface EFS of the phase modulation element 54S is equal to the number of modulation parts arranged in a matrix. The number of modulators is greater than the number of modulators arranged in parallel in the direction perpendicular to the longitudinal direction.

In this embodiment, as in the third embodiment as the first aspect, the power supplied to the light sources 52R, 52G, and 52B is adjusted, and the laser beams are alternately emitted from each of the light sources 52R, 52G, and 52B. Lights LR, LG, and LB are emitted alternately from each light emitting optical system 51R, 51G, and 51B. Therefore, the lights LR, LG, and LB having mutually different wavelength bands emitted from the light emitting optical systems 51R, 51G, and 51B are sequentially incident on the phase modulation element 54S. The phase modulation element 54S sequentially emits light DLR, DLG, and DLB obtained by diffracting the incident light LR, LG, and LB. In addition, in FIG. 12, these optical lights DLR, DLG, and DLB are shown shifted.

In this embodiment, as in the fourth embodiment, the shapes of the lights LR, LG, and LB from the light sources 52R, 52G, and 52B, which are semiconductor lasers, are not adjusted. The shape of the LB incident spot is approximately elliptical. In this embodiment, the size of each of these approximately elliptical incident spots is such that it can include at least one modulation section, and the long axis of each of these incident spots is in the longitudinal direction of the incident surface EFS of the phase modulation element 54S. It is said that it is roughly parallel to Furthermore, these incident spots overlap each other.

The phase modulation element 54S of this embodiment can change the phase modulation pattern according to the wavelength bands of the incident lights LR, LG, and LB in the same way as in the third embodiment as the first aspect. , a first light DLR that is a red component of the low beam, a second light DLG that is a green component of the low beam, and a third light DLB that is a blue component of the low beam are sequentially emitted. These lights DLR, DLG, and DLB are each emitted from the opening 36H of the cover 36 and are sequentially irradiated to the outside of the vehicle headlamp 1 via the front cover 12. The vehicle headlamp 1 of the present embodiment has a low beam light distribution pattern by combining these lights DLR, DLG, and DLB by the afterimage phenomenon, as in the third embodiment as the first aspect. Emit PL light.

In this embodiment as the second aspect, as described above, the longitudinal direction of the entrance surface EFS of the phase modulation element 54S and the longitudinal direction of the respective incident spots of the lights LR, LG, and LB from the light sources 52R, 52G, and 52B are Direction is assumed to be non-perpendicular. Therefore, in the vehicle headlamp 1 of this embodiment, as in the fourth embodiment, the lights LR, LG, and LB from the light sources 52R, 52G, and 52B do not need to be adjusted in shape. Parts of the incident spots of LG and LB can be suppressed from protruding from the incident surface EFS of the phase modulation element 54S. Therefore, the vehicle headlamp 1 of this embodiment can suppress increase in size while suppressing a decrease in energy efficiency. Further, in the vehicle headlamp 1 of the present embodiment, the phase modulation element that diffracts the lights LR, LG, and LB from the three light sources 52R, 52G, and 52B can be used as a common phase modulation element. The number of points can be reduced or the size can be reduced.

Note that the vehicle lamp according to the second aspect includes a light source and a phase modulation element having at least one modulation section that diffracts the light from the light source to form a predetermined light distribution pattern. , the light incidence surface of the phase modulation element and the light incidence spot of the phase modulation element have a longer shape in a predetermined direction than in other directions, and the size of the incidence spot is determined by the size of at least one modulation section. There is no particular limitation as long as the longitudinal direction of the incident surface of the phase modulation element and the longitudinal direction of the incident spot are non-perpendicular. In a vehicle lamp with such a configuration, the incident light can be adjusted without adjusting the shape of the light from the light source, compared to a case where the longitudinal direction of the incident surface of the phase modulation element and the longitudinal direction of the incident spot are perpendicular. It is possible to prevent a part of the spot from protruding from the incident surface of the phase modulation element, and it is possible to suppress the increase in size while suppressing a decrease in energy efficiency.

Further, in the fourth to sixth embodiments as the second aspect, the vehicle headlamp 1 as the vehicle lamp emits a low beam, but the vehicle lamp as the first aspect emits a low beam. The light used is not limited to low beam. For example, the vehicle lamp may emit light having a high beam light distribution pattern PH shown in FIG. 5(B), or may emit light constituting an image. In other words, each of the phase modulation elements 54R, 54G, and 54B in the phase modulation element assembly 54 of the fourth and fifth embodiments emits light such that the combined light forms a light distribution pattern that includes the intensity distribution of the high beam. It is assumed that it diffracts. Further, the phase modulation element 54S of the sixth embodiment is configured to diffract light so that the combined light due to the afterimage effect forms a light distribution pattern including the intensity distribution of the high beam. Further, in the case where the vehicular lamp emits light constituting an image, the direction of the light emitted by the vehicular lamp and the position at which the vehicular lamp is attached to the vehicle are not particularly limited.

Further, in the fourth to sixth embodiments as the second aspect, the phase modulation elements 54R, 54G, 54B, and 54S are reflective phase modulation elements. However, for example, an LCD, a GLV, a diffraction grating, etc. may be used as the phase modulation element.

Further, the vehicle headlamp according to the second embodiment may have the same configuration as the vehicle headlamp 1 according to the first embodiment shown in FIG. That is, the optical system unit 50 may be configured to include three phase modulating elements 54R, 54G, 54B and a combining optical system 55, which are spaced apart from each other, instead of the phase modulating element assembly 54 and the light guiding optical system 155. In this case, the lights DLR, DLG, and DLB emitted from the three phase modulation elements 54R, 54G, and 54B are combined by the combining optical system 55, and this combined light is emitted from the vehicle headlamp 1.

Further, in the fourth embodiment as the second aspect, the first phase modulation element 54R, the second phase modulation element 54G, and the third phase modulation element 54B of the phase modulation element assembly 54 are adjacent to each other in the vertical direction and are parallel to each other. It had been. Further, in the fifth embodiment as the second aspect, the first phase modulation element 54R, the second phase modulation element 54G, and the third phase modulation element 54B of the phase modulation element assembly 54 are horizontally adjacent to each other in parallel. It had been. However, the direction in which these phase modulation elements 54R, 54G, and 54B are arranged in parallel is not particularly limited, and for example, they may be arranged in parallel in the vertical direction and the horizontal direction.

Further, in the fourth and sixth embodiments as the second aspect, the light guide optical system 155 included a reflection mirror 155m, a first optical element 155f, and a second optical element 155s. However, the light guiding optical system 155 only needs to guide the lights LR, LG, and LB emitted from the respective light emitting optical systems 51R, 51G, and 51B to the phase modulating element assembly 54 and the phase modulating element 54S, and the fourth embodiment The present invention is not limited to the form or the configuration of the sixth embodiment. For example, the light guiding optical system 155 does not need to include the reflecting mirror 155m. In such a case, the light LR emitted from the first light emitting optical system 51R is made incident on the first optical element 155f. Further, in the fourth embodiment and the sixth embodiment, a bandpass filter that transmits light in a predetermined wavelength band and reflects light in other wavelength bands is used in the first optical element 155f and the second optical element 155s. It's okay.

Further, in the fourth and sixth embodiments as the second aspect, the optical system unit 50 converts the lights LR, LG, and LB emitted from the light emitting optical systems 51R, 51G, and 51B into the phase modulation element assembly 54 and the phase modulation It was equipped with a light guide optical system 155 that guides the light to the element 54S. However, the optical system unit 50 does not need to include the light guiding optical system 155. In this case, the light emitting optical systems 51R, 51G, and 51B are arranged so that these lights LR, LG, and LB are incident on the phase modulation element assembly 54 and the phase modulation element 54S.

Further, in the fourth and fifth embodiments as the second aspect, the optical system unit 50 includes a combining optical system that combines the first light DLR, the second light DLG, and the third light DLB. There wasn't. However, the optical system unit 50 of the fourth and fifth embodiments may include a synthetic optical system similarly to the second embodiment as the first aspect.

Further, in the fifth embodiment as the second aspect, the optical system unit 50 is a light guide optical system that guides the lights LR, LG, and LB emitted from the light emitting optical systems 51R, 51G, and 51B to the phase modulation element assembly 54. was not equipped with. However, the optical system unit 50 of the fifth embodiment may include a light guide optical system similarly to the fourth embodiment.

Furthermore, in the fourth to sixth embodiments as the second aspect, the lamp unit 20 did not include an imaging lens system including an imaging lens. However, the lamp unit 20 may include an imaging lens system, and the light emitted from the optical system unit 50 may be emitted through this imaging lens system. With such a configuration, it is possible to easily make the light distribution pattern of the emitted light wider. Note that "wide" here means that it is wide when comparing light distribution patterns formed on a vertical plane a predetermined distance away from the vehicle.

Furthermore, in the fourth to sixth embodiments as the second aspect, the incident spots SR, SG, and SB were generally elliptical. However, the shapes of the incident spots SR, SG, and SB only need to be longer in a predetermined direction than in other directions.

Further, in the fourth to sixth embodiments as the second aspect, the shape of each of the phase modulation elements 54R, 54G, 54B, and 54S is approximately rectangular, and the incident surface of each is also approximately rectangular. However, the shapes of the entrance surfaces of the phase modulation elements 54R, 54G, 54B, and 54S only need to be longer in a predetermined direction than in other directions.

Further, in the fourth to sixth embodiments as the second aspect, the longitudinal direction of the incident surface of each of the phase modulation elements 54R, 54G, 54B, and 54S is the horizontal direction. However, the longitudinal direction of the incident surfaces of the phase modulation elements 54R, 54G, 54B, and 54S is not particularly limited, and may be the vertical direction.

Furthermore, in the fourth and fifth embodiments as the second aspect, all three phase modulation elements 54R, 54G, and 54B are integrally formed. However, from the viewpoint of reducing the number of parts, if at least one phase modulation element among the plurality of phase modulation elements is connected to at least one other phase modulation element and formed integrally with this other phase modulation element, good.

Further, in the fifth embodiment as the second aspect, all three phase modulation elements 54R, 54G, and 54B are arranged adjacently in parallel. However, it is only necessary that at least two phase modulation elements are arranged in parallel, and that the longitudinal direction of the entrance plane of the at least two parallel phase modulation elements is parallel to the direction in which these phase modulation elements are arranged in parallel. For example, in the fifth embodiment, the third phase modulation element 54B in the phase modulation element assembly 54 may be provided separately from the phase modulation element assembly 54.

Further, in the sixth embodiment as the second aspect, the three light sources 52R, 52G, and 52B alternately emit light. However, from the viewpoint of reducing the number of parts and downsizing, it is sufficient that at least two light sources emit light alternately. In this case, the light emitted from the phase modulation element into which the light emitted from at least two light sources enters is combined by the afterimage effect, and the combined light and the light emitted from the other phase modulation element are combined by this afterimage effect. Then, light with a predetermined light distribution pattern is irradiated.

Further, in the fourth and fifth embodiments as the second aspect, three light sources 52R, 52G, 52B that emit laser beams in different wavelength bands and three phase modulation elements 54R, 54G, 54B are integrated. The optical system unit 50 including one phase modulation element assembly 54 has been described as an example. Further, in the sixth embodiment, the optical system unit 50 including three light sources 52R, 52G, and 52B that emit laser beams in different wavelength bands and one phase modulation element 54S was described as an example. However, the optical system unit only needs to include at least one light source and a phase modulation element corresponding to this light source. For example, the optical system unit may include a light source that emits white laser light and a phase modulation element that diffracts and emits the white laser light that is emitted from the light source. Further, when the optical system unit includes a plurality of light sources and phase modulation elements, at least one light source only needs to correspond to each phase modulation element. For example, light that is a combination of lights emitted from a plurality of light sources may be input to one phase modulation element.

(Seventh embodiment)
Next, a seventh embodiment as a third aspect of the present invention will be described. Note that components that are the same or similar to those in the first embodiment are given the same reference numerals and redundant explanations will be omitted, unless otherwise specified.

FIG. 13 is a diagram showing a part of the lamp unit 20 in the seventh embodiment as a third aspect of the present invention, and is a longitudinal sectional view showing a part of the vertical cross section of the lamp unit 20. FIG. 13 shows the optical system unit 50 in the lamp unit 20. As shown in FIG. 13, in the optical system unit 50 of this embodiment, the positional relationship between the light sources 52R, 52G, 52B and the light guiding optical system 155 is different from that of the optical system unit 50 of the first embodiment. The positional relationship between the optical system 155 and the light guiding optical system 155 is different. In this embodiment, these light sources 52R, 52G, and 52B are arranged so that the optical path length from the second light source 52G to the phase modulation element assembly 54 is the longest, and from the third light source 52B to the phase modulation element assembly 54. The lamp is arranged in the lamp chamber R so that the optical path length up to the lamp is the shortest. The first light source 52R emits red laser light upward, the second light source 52G emits green laser light forward, and the third light source 52B emits blue laser light forward.

In addition, in this embodiment, the total number of luminous fluxes of the red laser beam emitted from the first light source 52R, the total number of luminous fluxes of the green laser beam emitted from the second light source 52G, and the total number of luminous fluxes of the blue laser beam emitted from the third light source 52B. The total number of luminous fluxes is the same.

A first collimating lens 53R is arranged above the first light source 52R. A second collimating lens 53G is arranged in front of the second light source 52G. A third collimating lens 53B is arranged in front of the third light source 52B.

In this embodiment, the light guide optical system 155 includes a first optical element 155f and a second optical element 155s. The first optical element 155f is disposed above the first collimating lens 53R and in front of the second collimating lens 53G, and is inclined at approximately 45 degrees with respect to the front-back direction and the up-down direction. The first optical element 155f is, for example, a wavelength selection filter in which an oxide film is laminated on a glass substrate, and transmits light with a wavelength longer than a predetermined wavelength and reflects light with a wavelength shorter than the predetermined wavelength. The type and thickness of the oxide film are adjusted as follows. In this embodiment, the first optical element 155f is configured to transmit red component light emitted from the first light source 52R and reflect green component light emitted from the second light source 52G. In this embodiment, the red laser light emitted from the first collimating lens 53R and the green laser light emitted from the second collimating lens 53G are emitted upward from different positions on the emitting surface of the first optical element 155f.

The second optical element 155s is arranged above the first optical element 155f and in front of the third collimating lens 53B, and is inclined at approximately 45 degrees in the same direction as the first optical element 155f with respect to the front-rear direction and the up-down direction. There is. This second optical element 155s is used as a wavelength selection filter similarly to the first optical element 155f. In this embodiment, the second optical element 155s transmits red component light emitted from the first light source 52R and green component light emitted from the second light source 52G, and transmits blue component light emitted from the third light source 52B. configured to reflect. In this embodiment, the red laser light emitted from the first optical element 155f, the green laser light emitted from the first optical element 155f, and the blue laser light emitted from the third collimating lens 53B are emitted from the second optical element 155s. Emits upward from different positions on the surface.

The phase modulation element assembly 54 is arranged above the light guide optical system 155, and is inclined at approximately 45° in the same direction as the optical elements 155f and 155s with respect to the front-rear direction and the up-down direction. The phase modulation element assembly 54 includes a plurality of phase modulation elements, similar to the phase modulation element assembly 54 of the first embodiment. Specifically, the phase modulation element assembly 54 includes a first phase modulation element 54R that modulates the phase of the red laser light to make the red laser light into a predetermined light distribution pattern, and a first phase modulation element 54R that modulates the phase of the green laser light. a second phase modulation element 54G that modulates the phase of the blue laser light to make the blue laser light a predetermined light distribution pattern; and a third phase modulation element 54B that modulates the phase of the blue laser light to make the blue laser light a predetermined light distribution pattern. These phase modulation elements 54R, 54G, and 54B are arranged in one direction.

In this embodiment, each of the phase modulation elements 54R, 54G, and 54B is a reflection type phase modulation element that reflects and diffracts incident light and emits it, and specifically, it is a reflection type LCOS. .

Next, the configuration of the phase modulation element assembly 54 will be explained in more detail.

The phase modulation elements 54R, 54G, and 54B of this embodiment have the same configuration as the phase modulation elements 54R, 54G, and 54B of the first embodiment. However, the external shapes of the phase modulating elements 54R, 54G, and 54B when viewed from the front are different from the external shapes of the phase modulating elements 54R, 54G, and 54B of the first embodiment. FIG. 14 is a front view schematically showing phase modulation elements 54R, 54G, and 54B shown in FIG. 13. As shown in FIG. 14, the phase modulation element assembly 54 is formed into a substantially rectangular shape when viewed from the front, with a first phase modulation element 54R located at the top and a first phase modulation element 54R located below the first phase modulation element 54R. It has a second phase modulation element 54G and a third phase modulation element 54B located below the second phase modulation element 54G. A drive circuit 60R is electrically connected to this phase modulation element assembly 54.

Here, in FIG. 14, the incident spot SR of the red laser beam incident on the first phase modulation element 54R is a solid line, the incident spot SG of the green laser beam incident on the second phase modulation element 54G is a broken line, and the third An incident spot SB of the blue laser beam incident on the phase modulation element 54B is indicated by a dashed line. In this embodiment, among the incident spots SR, SG, and SB, the incident spot SB of the blue laser beam is the largest, and the incident spot SG of the green laser beam is the smallest. In other words, the longer the optical path length from the light source to the phase modulating element assembly 54, the smaller the spot diameter is made. Note that although the incident spots SR, SG, and SB are shown as circles in FIG. 14, the outer shape of the incident spots may be non-circular, for example, elliptical.

In this embodiment, each of the modulation units MPR of the first phase modulation element 54R has the same phase modulation pattern corresponding to red laser light. Furthermore, each of the modulation units MPG of the second phase modulation element 54G has the same phase modulation pattern corresponding to green laser light. Further, each of the modulation units MPB of the third phase modulation element 54B has the same phase modulation pattern corresponding to blue laser light.

In this embodiment, when the entire incident spot SR is incident on the first phase modulation element 54R as shown in FIG. 14, the incident spot SR includes at least one modulation section MPR. As described above, since each modulation unit MPR has the same phase modulation pattern, when the entire incident spot SR is incident on the first phase modulation element 54R, the red laser emitted from the first phase modulation element 54R The light distribution pattern of light is a predetermined light distribution pattern based on the phase modulation pattern of the modulation unit MPR. In this embodiment, this predetermined light distribution pattern is a light distribution pattern in which a low beam light distribution pattern PL shown in FIG. 5(A) can be formed. Hereinafter, the red laser light emitted from the phase modulation element assembly 54 may be referred to as the first light DLR.

Furthermore, when the entire incident spot SG is incident on the second phase modulation element 54G as shown in FIG. 14, the incident spot SG includes at least one modulation section MPG. As described above, each modulation unit MPG has the same phase modulation pattern, so when the entire incident spot SG is incident on the second phase modulation element 54G, the green laser emitted from the second phase modulation element 54G The light distribution pattern of light is a predetermined light distribution pattern based on the phase modulation pattern of the modulator MPG. In this embodiment, this predetermined light distribution pattern is a light distribution pattern in which a low beam light distribution pattern PL can be formed. Hereinafter, the green laser light emitted from the phase modulation element assembly 54 may be referred to as second light DLG.

Furthermore, when the entire incident spot SB is incident on the third phase modulation element 54B as shown in FIG. 14, the incident spot SB includes at least one modulation section MPB. As described above, each modulation unit MPB has the same phase modulation pattern, so when the entire incident spot SB is incident on the third phase modulation element 54B, the blue laser emitted from the third phase modulation element 54B The light distribution pattern of the light is a predetermined light distribution pattern based on the phase modulation pattern of the modulator MPB. In this embodiment, this predetermined light distribution pattern is a light distribution pattern in which a low beam light distribution pattern PL can be formed. Hereinafter, the blue laser light emitted from the phase modulation element assembly 54 may be referred to as third light DLB.

Next, light emission from the vehicle headlamp 1 of this embodiment will be explained. Specifically, a case where a low beam is emitted from the vehicle headlamp 1 will be described.

When power is supplied to the first light source 52R, red laser light is generated by the first light source 52R. As shown in FIG. 13, this red laser light is emitted upward and is collimated by the first collimating lens 53R. Furthermore, when power is supplied to the second light source 52G, green laser light is generated by the second light source 52G, and this green laser light is emitted forward. This green laser light is collimated by the second collimating lens 53G. Furthermore, when power is supplied to the third light source 52B, blue laser light is generated by the third light source 52B, and this blue laser light is emitted forward. This blue laser light is collimated by the third collimating lens 53B.

As described above, the red laser light emitted from the first collimator lens 53R is transmitted through the first optical element 155f arranged above the first collimator lens 53R. Moreover, the green laser light emitted from the second collimating lens 53G is reflected by the first optical element 155f arranged in front of the second collimating lens 53G, as described above. That is, this green laser light changes direction by 90 degrees at the first optical element 155f and is emitted forward. As described above, these red laser beams and green laser beams are emitted from different positions on the emission surface of the first optical element 155f. Therefore, the red laser light and green laser light emitted from the first optical element 155f propagate upward while generally being lined up in the front-rear direction.

As described above, the red laser beam and the green laser beam pass through the second optical element 155s arranged above the first optical element 155f. Moreover, the blue laser light emitted from the third collimating lens 53B is reflected by the second optical element 155s arranged in front of the third collimating lens 53B, as described above. That is, this blue laser light changes direction by 90 degrees at the second optical element 155s and is emitted forward. As described above, these red laser light, green laser light, and blue laser light are emitted from different positions on the emitting surface of the second optical element 155s. Therefore, the red laser light, green laser light, and blue laser light emitted from the second optical element 155s propagate upward while generally being lined up in the front-rear direction. Specifically, among the red laser light, green laser light, and blue laser light, the red laser light is located furthest to the front, and the blue laser light is located furthest back.

As described above, with the red laser light located at the frontmost side and the blue laser light located at the rearmost side, the red laser light, green laser light, and blue laser light propagate upward, resulting in the red laser light being The light enters the first phase modulation element 54R of the phase modulation element assembly 54 arranged above the second optical element 155s. Further, the green laser light is incident on the second phase modulation element 54G of the phase modulation element assembly 54. Further, the blue laser light is incident on the third phase modulation element 54B of the phase modulation element assembly 54.

In this embodiment, as described above, among the optical path lengths from each light source to the phase modulation element assembly 54, the optical path length of the green laser light from the second light source 52G to the phase modulation element assembly 54 is the longest. Therefore, the optical path length of the blue laser light from the third light source 52B to the phase modulation element assembly 54 is the shortest.

The red laser light incident on the first phase modulation element 54R is diffracted by the first phase modulation element 54R and becomes the first light DLR. This first light DLR is emitted forward from the first phase modulation element 54R. As described above, this first light DLR has a low beam light distribution pattern PL. Further, the green laser light that has entered the second phase modulation element 54G is diffracted by the second phase modulation element 54G and becomes second light DLG. This second light DLG is emitted forward from the second phase modulation element 54G. As described above, this second light DLG has a low beam light distribution pattern PL. Further, the blue laser light that has entered the third phase modulation element 54B is diffracted by the third phase modulation element 54B and becomes third light DLB. This third light DLB is emitted forward from the third phase modulation element 54B. As described above, this third light DLB has a low beam light distribution pattern PL.

In this way, the lights DLR, DLG, and DLB emitted from the phase modulation element assembly 54 all have a low beam light distribution pattern. Therefore, when these lights DLR, DLG, and DLB are emitted from the opening 36H of the cover 36 and propagate forward by a predetermined distance, the lights DLR, DLG, and DLB overlap to form a low beam that is white light. obtain.

Here, in a vehicle lamp using a phase modulating element as described in Patent Document 1 mentioned above, it is conceivable to synthesize a desired color using a plurality of semiconductor lasers that emit laser beams with different wavelengths. However, when using a plurality of semiconductor lasers, the distances from each semiconductor laser to a phase modulation element that forms a desired light distribution pattern may be different. Further, in general, the diameters of laser beams of different wavelengths emitted from a plurality of semiconductor laser elements tend to be different from each other. In such a case, it may be possible to use a lens or a shade to align the spot diameters of the laser beams incident on the phase modulation element, but this would result in an increase in the number of parts.

Therefore, the vehicle headlamp 1 of the present embodiment as a third aspect includes a plurality of light sources 52R, 52G, 52B that emit light of different wavelengths, and a plurality of light sources 52R, 52G, 52B that emit light from each other. It includes phase modulation elements 54R, 54G, and 54B that each form a predetermined light distribution pattern for a plurality of lights by diffracting the light. The sizes of the incident spots SR, SG, and SB on the phase modulation elements 54R, 54G, and 54B of light having different wavelengths are different from each other. Therefore, in the vehicle headlamp 1 of this embodiment, it is possible to eliminate the provision of optical components for adjusting the sizes of the incident spots SR, SG, and SB of light having different wavelengths, and an increase in the number of components can be suppressed. can be done.

Furthermore, when the vehicle on which the vehicle headlamp 1 is mounted vibrates and the light sources 52R, 52G, and 52B shake, the laser beams emitted from the light sources 52R, 52G, and 52B also shake, so that the incident spots SR, SG, and SB are It may move on the entrance plane of the phase modulation element assembly 54. In this case, if the distance traveled by the incident spot is long, the incident spot may protrude outside the phase modulation element assembly 54 or protrude into a different phase modulation element. For example, consider a case where an incident spot of a laser beam of a predetermined color protrudes into a phase modulation element corresponding to a laser beam of a different color. In this case, since the phase modulation pattern of the protruding area is a phase modulation pattern corresponding to a laser beam of a different color, the light distribution pattern of the laser beam of the predetermined color emitted from the protruding area is different from that of the low beam. It can be a light distribution pattern. When such light having a light distribution pattern different from that of the low beam is mixed in the light emitted from the vehicle headlamp 1, the formation of the low beam may be inhibited.

When the light source fluctuates as described above, the longer the optical path length of the light to the irradiation position is, the larger the fluctuation width of the incident spot of the light at the irradiation position tends to be. According to the vehicle headlamp 1 of this embodiment, as described above, the longer the optical path length of the light from the light source to the phase modulation element assembly 54, the smaller the spot diameter, so that the spot diameter is reduced as shown in FIG. , the incident spot SG of the green laser beam is smaller than the incident spots SR and SB. Therefore, even if the incident spot SG of the green laser beam moves significantly due to vibrations of the vehicle, the incident spot SG can be prevented from protruding into the first phase modulation element 54R or the third phase modulation element 54B. Therefore, according to the vehicle headlamp 1 of this embodiment, a desired light distribution pattern such as a low beam can be prevented from being disrupted.

In this way, the size of the incident spot of each laser beam differs depending on the optical path length to the irradiation position, so the spot diameter can be adjusted from the phase modulation element without installing an optical system etc. to adjust the size of the incident spot. Protrusion can be suppressed, and an increase in the number of parts can be suppressed.

Incidentally, the incident spots SR and SB of the red laser beam and the blue laser beam, which have longer optical path lengths than the green laser beam, may have the same size, and only the size of the incident spot SG may be reduced. That is, among at least two lights having different incident spot sizes, the longer the optical path length to the phase modulation element, the smaller the incident spot. However, as mentioned above, the longer the optical path length from the light source to the phase modulation element assembly 54, the smaller the incident spot, so that the size of the incident spot will correspond to the optical path length, so that the desired light distribution can be achieved. Patterns may become easier to obtain.

(Eighth embodiment)
Next, an eighth embodiment as the third aspect of the present invention will be described. Note that components that are the same or equivalent to those in the seventh embodiment are given the same reference numerals and redundant explanations will be omitted, unless otherwise specified.

FIG. 15 is a diagram similar to FIG. 13 showing a part of the lamp unit 20 of the vehicle headlamp 1 in the eighth embodiment as the third aspect of the present invention. Note that in FIG. 15, the heat sink 30, cover 36, etc. of the lamp unit 20 are omitted for easy understanding. As shown in FIG. 15, in the lamp unit 20 according to the eighth embodiment, one phase modulation element 54S is provided, and a phase modulation element is provided for each light source to form a phase modulation element assembly 54. This is different from the lamp unit 20 in the seventh embodiment. The configuration of the lamp unit 20 in the eighth embodiment will be described below.

In this embodiment, the first light source 52R emits red laser light upward, the second light source 52G emits green laser light forward, and the third light source 52B emits blue laser light forward. These red laser light, green laser light, and blue laser light enter the phase modulation element 54S via the combining optical system 55. These light sources 52R, 52G, and 52B are arranged so that the optical path length from the second light source 52G to the phase modulation element 54S is the longest, and the optical path length from the third light source 52B to the phase modulation element 54S is the shortest. , is arranged in the lamp room R. Note that the total number of luminous fluxes of red laser light, green laser light, and blue laser light in this embodiment is the same as in the seventh embodiment.

FIG. 16 is a front view schematically showing the phase modulation element 54S shown in FIG. 15 together with an incident spot of light incident on the phase modulation element 54S. As shown in FIG. 16, in this embodiment, the incident spot SG of the green laser beam having the longest optical path length to the phase modulation element 54S is made the smallest, and the incident spot SG of the blue laser beam having the shortest optical path length to the phase modulation element 54S. The incident spot SB is made the largest. Note that although the incident spots SR, SG, and SB are shown as circles in FIG. 16, the outer shape of the incident spots may be non-circular, for example, elliptical.

The light sources 52R, 52G, and 52B of this embodiment are connected to a control system (not shown). This control system prevents the light sources 52G and 52B from emitting light while the light source 52R emits red laser light, and prevents the light sources 52R and 52B from emitting light while the light source 52G emits green laser light. is not emitted, and while the light source 52B is emitting blue laser light, the light from the light sources 52R and 52G is not emitted. That is, the vehicle headlamp 1 in this embodiment switches the emission of light from the light sources 52R, 52G, and 52B at a predetermined cycle based on the control of the control system.

Note that, similarly to the seventh embodiment, the laser beams emitted from the light sources 52R, 52G, and 52B are collimated by collimating lenses 53R, 53G, and 53B.

As shown in FIG. 15, a combining optical system 55 is provided above the collimating lens 53R and in front of the collimating lenses 53G and 53B. That is, a first optical element 55f is provided above the collimating lens 53R and in front of the collimating lens 53G, and a second optical element 55s is provided above the first optical element 55f and in front of the collimating lens 53B. These optical elements 55f and 55s are arranged at an angle of about 45 degrees in the same direction in the front-rear direction and the up-down direction.

One phase modulation element 54S is provided above the second optical element 55s. This phase modulation element 54S is arranged at a position where the red laser beam, green laser beam, and blue laser beam that have passed through the combining optical system 55 can be incident. The phase modulation element 54S in this embodiment is, for example, a reflective LCOS. This phase modulation element 54S is arranged at an angle of about 45 degrees in the front-rear direction and the up-down direction, and the direction of the inclination is the same as that of the optical elements 55f and 55s.

Next, light emission from the lamp unit 20 of this embodiment will be explained. Specifically, a case where a low beam is emitted from the vehicle headlamp 1 will be described.

As described above, the lamp unit 20 in this embodiment switches the emission of light from the light sources 52R, 52G, and 52B at a predetermined cycle based on the control of the control system. For example, first, red laser light is emitted from the first light source 52R for a predetermined period of time. During this time, the laser beams from the light sources 52G and 52B are not emitted. This red laser light is collimated by the collimating lens 53R, and then enters the phase modulation element 54S via the combining optical system 55. As shown in FIG. 16, this red laser light is incident on the incident surface of the phase modulation element 54S at an incident spot SR of a predetermined size.

When the red laser light is incident on the phase modulation element 54S, the red laser light is diffracted and reflected by the phase modulation element 54S, and the first light DLR having the low beam light distribution pattern PL is emitted forward.

After a predetermined period of time has elapsed, the light source 52R stops emitting light, and instead of emitting light from the light source 52R, green laser light is emitted from the light source 52G for a predetermined period of time. This green laser light is collimated by a collimating lens 53G, and then enters a phase modulating element 54S via a combining optical system 55. As described above, this green laser light is incident on the incident surface of the phase modulation element 54S at an incident spot SG that is smaller than the incident spot SR of the red laser beam.

When the green laser light is incident on the phase modulation element 54S, the green laser light is diffracted and reflected by the phase modulation element 54S, and second light DLG having a low beam light distribution pattern PL is emitted forward.

After a further predetermined period of time has elapsed, the light source 52G stops emitting light, and instead of emitting light from the light source 52G, blue laser light is emitted from the light source 52B for a predetermined period of time. This blue laser light is collimated by the collimating lens 53B, and then enters the phase modulation element 54S via the combining optical system 55. As described above, this blue laser light is incident on the incident surface of the phase modulation element 54S at an incident spot SB that is larger than the incident spot SR of the red laser beam.

When the blue laser light is incident on the phase modulation element 54S, the blue laser light is diffracted and reflected by the phase modulation element 54S, and third light DLB having a low beam light distribution pattern PL is emitted forward.

Under the control of the control system, the light emission cycle is repeated at a predetermined period.

In this way, the control system switches the emission of light from the light sources 52R, 52G, and 52B at a predetermined cycle, so that the lights DLR, DLG, and DLB are switched and emitted from the vehicle headlamp 1 at a predetermined cycle. . If this cycle is shorter than the temporal resolution of human vision, an afterimage effect will occur, as in the third embodiment as the first aspect, and the person will perceive that different colors of light are being combined and irradiated. It is possible. Therefore, by making the period in this embodiment shorter than the human time resolution, a person can recognize that the low beam, which is white light, is emitted from the vehicle headlamp 1.

As mentioned above, the temporal resolution of human vision is approximately 1/30 s, so the period is preferably 1/30 s or less, more preferably 1/60 s or less. Note that even if the period is greater than 1/30 s, the afterimage effect may occur. For example, even if the period is 1/15 seconds, the afterimage effect may occur.

As described above, according to the vehicle headlamp 1 of the present embodiment, the incident spot SG of the green laser light, which has a longer optical path length to the phase modulation element assembly 54 than the red laser light and the blue laser light, is the longest. Since it is made small, similarly to the seventh embodiment, even if the incident spot SG of the green laser beam moves significantly due to vibrations of the vehicle, the incident spot SG can be prevented from protruding from the phase modulation element 54S. Therefore, according to the vehicle headlamp 1 of this embodiment, a desired light distribution pattern such as a low beam can be easily obtained.

In this way, the size of the incident spot of each laser beam differs depending on the optical path length to the irradiation position, so the spot diameter can be adjusted from the phase modulation element without installing an optical system etc. to adjust the size of the incident spot. Protrusion can be suppressed, and an increase in the number of parts can be suppressed. Moreover, according to the vehicle headlamp 1 in this embodiment, since the laser beams from the light sources 52R, 52G, and 52B enter the common phase modulation element 54S, the number of phase modulation elements is reduced to one. Therefore, an increase in the number of parts can be more effectively suppressed.

(Ninth embodiment)
Next, a ninth embodiment as the third aspect of the present invention will be described. Note that components that are the same or equivalent to those in the seventh embodiment are given the same reference numerals and redundant explanations will be omitted, unless otherwise specified.

FIG. 17 is a diagram similar to FIG. 13 showing a part of the lamp unit 20 of the vehicle headlamp 1 in the ninth embodiment as the third aspect of the present invention. As shown in FIG. 17, the lamp unit 20 according to the ninth embodiment is different from the lamp unit 20 according to the ninth embodiment in that phase modulation elements 54R, 54G, and 54B are arranged apart from each other. The lamp unit 20 in the ninth embodiment will be described below.

As shown in FIG. 17, the optical system unit 50 of the lamp unit 20 in this embodiment includes a first light source 52R, a second light source 52G, a third light source 52B, a first phase modulation element 54R, and a second phase modulation element 54R. The main components include a modulation element 54G, a third phase modulation element 54B, and a combining optical system 55. In this embodiment, the phase modulation elements 54R, 54G, and 54B are reflective phase modulation elements that reflect and diffract incident light and emit the light, and specifically, are reflective LCOS.

The first light source 52R emits a predetermined total number of luminous fluxes of red laser light upward. The second light source 52G emits green laser light with a larger total luminous flux number than the red laser light backward. The third light source 52B emits blue laser light with a larger total luminous flux number than the green laser light backward. That is, in this embodiment, the total number of luminous fluxes of the red laser beam is the smallest, and the total number of luminous fluxes of the blue laser beam is the largest.

Note that, similarly to the seventh embodiment, the laser beams emitted from the light sources 52R, 52G, and 52B are collimated by collimating lenses 53R, 53G, and 53B.

The first phase modulation element 54R is arranged above the first collimating lens 53R, and is inclined at approximately 45 degrees with respect to the front-back direction and the up-down direction. The red laser beam collimated by the collimating lens 53R is incident on the incident surface of the first phase modulating element 54R with an incident spot SR having a predetermined size.

The second phase modulation element 54G is arranged behind the second collimating lens 53G, and is arranged at an angle of about 45 degrees in the opposite direction to the first phase modulation element 54R with respect to the front-rear direction and the up-down direction. . The green laser beam collimated by the collimating lens 53G is incident on the incident surface of the second phase modulation element 54G at an incident spot SG that is larger than the above-mentioned incident spot SR.

The third phase modulation element 54B is arranged behind the third collimating lens 53B, and is arranged at an angle of about 45° in the opposite direction to the first phase modulation element 54R with respect to the front-rear direction and the up-down direction. . The blue laser beam collimated by the collimating lens 53B is incident on the incident surface of the third phase modulation element 54B at an incident spot SB that is larger than the above-mentioned incident spot SG.

As described above, in this embodiment, the incident spot SR of the red laser beam with the smallest total number of luminous fluxes is the smallest, and the incident spot SB of the blue laser beam with the largest total number of luminous fluxes is the largest.

Next, light emission from the vehicle headlamp 1 will be explained. Specifically, a case where a low beam is emitted from the vehicle headlamp 1 will be described.

The red laser beam emitted upward from the first light source 52R is collimated by the collimating lens 53R, and enters the first phase modulation element 54R at an incident spot SR of a predetermined size. This red laser light is diffracted and reflected by the first phase modulation element 54R, and first light DLR having a low beam distribution pattern PL is emitted forward.

The green laser beam emitted backward from the second light source 52G is collimated by a collimator lens 53G, and enters the second phase modulation element 54G at an incident spot SG larger than the incident spot SR. This green laser light is diffracted and reflected by the second phase modulation element 54G, and second light DLG having a low beam light distribution pattern PL is emitted upward.

The blue laser light emitted backward from the third light source 52B is collimated by the collimator lens 53B, and enters the third phase modulation element 54B at an incident spot SB that is larger than the incident spot SG. This blue laser light is diffracted and reflected by the third phase modulation element 54B, and third light DLB having a low beam light distribution pattern PL is emitted upward.

The first light DLR emitted from the first phase modulation element 54R is transmitted through the first optical element 55f of the combining optical system 55 arranged in front of the first phase modulation element 54R. The second light DLG emitted from the second phase modulation element 54G is reflected by the first optical element 55f arranged above the second phase modulation element 54G, and is emitted forward from the first optical element 55f. In this way, the first combined light LS1 consisting of the lights DLR and DLG propagates forward.

The first combined light LS1 emitted from the first optical element 55f is transmitted through the second optical element 55s of the combining optical system 55 arranged in front of the first optical element 55f. The third light DLB emitted from the third phase modulation element 54B is reflected by the second optical element 55s disposed above the third phase modulation element 54B, and is emitted forward from the second optical element 55s. In this way, the second combined light LS2 composed of the lights DLR, DLG, and DLB is emitted forward from the second optical element 55s.

As described above, the lights DLR, DLG, and DLB forming the second combined light all have a low beam light distribution pattern. Therefore, when the second combined light LS2 emitted from the aperture 36H propagates forward by a predetermined distance, the lights DLR, DLG, and DLB overlap to form a low beam that is white light.

As described above, according to the vehicle headlamp 1 in this embodiment, the incident spot SB of the blue laser beam with the largest total luminous flux number is made the largest, and the incident spot SR of the red laser beam with the smallest total luminous flux number is made the smallest. Therefore, the energy per unit area of the red laser beam incident on the phase modulation element 54R, the energy per unit area of the green laser beam incident on the phase modulation element 54G, and the energy per unit area of the blue laser beam incident on the phase modulation element 54B. The energy per unit area can be nearly equal. Therefore, it is possible to prevent a specific phase modulation element from deteriorating faster than other phase modulation elements, and it is possible to prevent the light distribution pattern from collapsing over a long period of time. Therefore, the useful life of the vehicle headlamp can be prevented from becoming short.

In this way, the size of the incident spot of each laser beam differs depending on the total number of light beams, so the energy per unit area of each laser beam can be equalized without the need for an optical system to adjust the size of the incident spot. Therefore, an increase in the number of parts can be suppressed.

(10th embodiment)
Next, a tenth embodiment as a third aspect of the present invention will be described. Note that components that are the same or equivalent to those in the seventh embodiment are given the same reference numerals and redundant explanations will be omitted, unless otherwise specified.

The lamp unit 20 of the vehicle headlamp 1 according to the tenth embodiment as the third aspect of the present invention includes three first light sources 52R, two second light sources 52G, and one third light source 52B. This is different from the lamp unit 20 in the seventh embodiment, which includes one each of light sources 52R, 52G, and 52B.

Although the light sources 52R, 52G, and 52B of this embodiment can be visually recognized as shown in FIG. 13 in a longitudinal cross-sectional view, three first light sources 52R are arranged along the depth direction perpendicular to the front-rear direction and the up-down direction, and the three first light sources 52R are Two second light sources 52G are arranged above the first light source 52R along the depth direction, and one third light source 52B is arranged above the two second light sources 52G. Note that in this embodiment, the total luminous flux of light emitted from each of the plurality of light sources is approximately the same.

In order to improve the brightness and white balance of white light, for example, among red light, green light, and blue light, the total luminous flux of red light should be the largest, and the total luminous flux of blue light should be the smallest. It may be preferable to do so. Therefore, in the lamp unit 20 of this embodiment, as described above, three first light sources 52R that emit red light are arranged to maximize the total luminous flux of red light, and the second light source 52R that emits green light is arranged to maximize the total luminous flux of red light. Two light sources 52G are arranged to make the total luminous flux of green light smaller than the total luminous flux of red light, and one third light source 52B that emits blue light is arranged to minimize the total luminous flux of blue light. are doing.

FIG. 18 is a front view showing the phase modulation element according to this embodiment along with the incident spot of light incident on the phase modulation element from the same viewpoint as FIG. 14. As shown in FIG. 18, in this embodiment, the number of first light sources 52R is three, which is the largest number, and each of the incident spots SR of red light emitted from these first light sources 52R corresponds to two incident spots of green light. It is smaller than the spot SG and one blue light incident spot SB. Further, each of the incident spots SG of the green light emitted from the two second light sources 52G is smaller than the incident spot SR. Further, the number of third light sources 52B is the smallest at one, and the incident spot SB of the blue light emitted from this third light source 52B is the largest. In this way, in this embodiment, the smaller the incident spot of light, the more light is emitted from a larger number of light sources.

By doing so, it may be possible to receive all the red light emitted from a larger number of light sources 52R without making the first phase modulation element 54R larger than the other phase modulation elements 54G and 54B. .

In this way, the smaller the incident spot, the more light is emitted from a larger number of light sources, so that the phase modulation element can be controlled without increasing the size of the phase modulation element, without the need for an optical system etc. to adjust the size of the incident spot. The modulation element can receive all the light emitted from a large number of light sources, and an increase in the number of parts can be suppressed.

Note that in this embodiment, an example has been described in which the number of first light sources 52R is the largest (three) and the number of third light sources 52B is the smallest (one); Among the two types of light, the smaller the incident spot of the light, the more the light needs to be emitted from more light sources.

Note that although the third aspect of the present invention has been described using the seventh to tenth embodiments as examples, the third aspect of the present invention is not limited to these.

For example, in the seventh and eighth embodiments as the third aspect, an example has been described in which the longer the optical path length of the laser beam to the phase modulation element, the smaller the incident spot on the phase modulation element, but the invention is not limited to this. . For example, similarly to the ninth embodiment, the incident spot on the phase modulation element may be made larger as the total number of light beams is larger. In this case, similarly to the ninth embodiment, the energy per unit area of the red laser beam incident on the phase modulation element 54R, the energy per unit area of the green laser beam incident on the phase modulation element 54G, and the energy per unit area of the red laser beam incident on the phase modulation element 54G, The energies per unit area of the blue laser light incident on 54B can be nearly the same. Therefore, it is possible to prevent a particular phase modulation element from deteriorating faster than other phase modulation elements.

Further, in the ninth embodiment as the third aspect, an example has been described in which the incident spot on the phase modulation element becomes larger as the total number of light beams becomes larger, but the invention is not limited to this. For example, similarly to the seventh and eighth embodiments, the longer the optical path length of the laser beam to the phase modulation element, the smaller the incident spot on the phase modulation element. In this case, in the vehicle headlamp 1 of the ninth embodiment, it may be easier to obtain a desired light distribution pattern.

Further, in the seventh to tenth embodiments as the third aspect, the incident spot SR of the red light emitted from the first light source 52R, the incident spot SG of the green light emitted from the second light source 52G, and the incident spot SG of the green light emitted from the second light source 52G, Although an example has been described in which the incident spots SB of the blue light emitted from the blue light 52B are all different, it is sufficient that at least two of the incident spots SR, SG, and SB are different in size. However, if the sizes of the incident spots SR, SG, and SB are all different, the size of the spot diameter can be adjusted more effectively, and an increase in the number of parts can be more effectively suppressed.

In addition, if the sizes of the incident spots SR, SG, and SB are all different, for example, taking into consideration that light with a longer wavelength tends to be refracted more, the incident spot of light with a longer wavelength may be made smaller. . For example, as shown in FIG. 19, the incident spot SR of red light having the longest wavelength, the incident spot SG of green light having a shorter wavelength than the red light, and the incident spot SB of blue light having the shortest wavelength are arranged in order of size. The incident spots SR, SG, and SB are made concentric circles. The red light, the green light, and the blue light are each refracted by the phase modulation element 54S, reflected by the phase modulation element 54S, and emitted from the phase modulation element 54S. As mentioned above, light with a longer wavelength tends to be refracted more, so the red light emitted from the phase modulation element 54S is refracted the most within the phase modulation element 54S, and the blue light emitted from the phase modulation element 54S is bent to the smallest extent within the phase modulation element 54S. Here, as described above, among the concentric incident spots SR, SG, and SB, the incident spot SR is the smallest and the incident spot SB is the largest, so the red light, green light, and blue light emitted from the phase modulation element 54S By propagating the light a predetermined distance, the respective outer edges of the red light, green light, and blue light overlap, and color blurring at the outer edge of the composite light consisting of the red light, green light, and blue light can be suppressed.

Further, in the seventh to tenth embodiments as the third aspect, an example was explained in which a reflective LCOS was used as the phase modulation element, but other types of phase modulation elements may be used as the phase modulation element. . For example, an LCD, a diffraction grating, or a GLV may be used.

Further, in the seventh to tenth embodiments as the third aspect, the vehicle headlamp 1 as the vehicle lamp emits a low beam, but the vehicle lamp as the third aspect emits a low beam. The light used is not limited to low beam. For example, a vehicle lamp in another embodiment may be configured to emit a low beam and a sign recognition light OHS, as shown in FIG. 5(A). Further, a vehicle lamp in another embodiment may be configured to emit light with a high beam light distribution pattern PH as shown in FIG. 5(B). In yet another embodiment, the vehicle lamp according to the third aspect of the present invention may be applied as a component of an image. In such a case, the direction of light emitted from the vehicle lamp and the mounting position of the vehicle lamp in the vehicle are not particularly limited.

(Eleventh embodiment)
Next, a tenth embodiment as the fourth aspect of the present invention will be described. Note that components that are the same or similar to those in the first embodiment are given the same reference numerals and redundant explanations will be omitted, unless otherwise specified.

FIG. 20 is a diagram showing a part of the lamp unit 20 in the eleventh embodiment as the fourth aspect of the present invention, and is a longitudinal cross-sectional view showing a part of the cross section of the lamp unit 20 in the vertical direction. As shown in FIG. 13, the lamp unit 20 of this embodiment differs from the lamp unit 20 of the first embodiment mainly in that it includes a case 40 instead of the cover 36. Further, the optical system unit 50 in this embodiment includes a plurality of phase modulation elements 54R, 54G, 54B instead of the phase modulation element assembly 54, a plurality of movable members 57R, 57G, 57B, and a guide. The main difference from the optical system unit 50 of the first embodiment is that a combining optical system 55 is provided instead of the light optical system 155.

In this embodiment, a case 40 is disposed on the upper surface of the base plate 31 of the heat sink 30. The case 40 of this embodiment includes a base 41 made of metal such as aluminum and a cover 42, and the base 41 is fixed to the upper surface of the base plate 31 of the heat sink 30. The base 41 is formed into a box shape with an opening extending from the front to the top, and a cover 42 is fixed to the base 41 so as to close the opening on the upper side. An opening 40H defined by the front end of the base 41 and the front end of the cover 42 is formed in the front of the case 40. An optical system unit 50 is arranged in a space inside the case 40. Note that the inner walls of the base 41 and the cover 42 are preferably treated with black alumite or the like to have light-absorbing properties. By making the inner walls of the base 41 and the cover 42 light-absorbing, it is possible to prevent light irradiated onto the inner wall of the base 41 from being reflected and emitted from the opening 40H in an unintended direction due to unintended reflection or refraction. Can be suppressed.

As shown in FIG. 20, the optical system unit 50 in this embodiment includes a first light source 52R, a second light source 52G, a third light source 52B, a first phase modulation element 54R, and a second phase modulation element 54G. , a third phase modulation element 54B, and a combining optical system 55 as main components. In this embodiment, the phase modulation elements 54R, 54G, and 54B are reflective phase modulation elements that reflect and diffract incident light and emit the light, and specifically, are reflective LCOS.

In this embodiment, the first light source 52R emits red laser light upward, the second light source 52G emits green laser light backward, and the third light source 52B emits blue laser light backward.

The first light source 52R is fixed to a movable part of a movable member 57R fixed to the base 41. The movable part of the movable member 57R is connected to a control part (not shown), and under the control of the control part, periodically moves in two directions: a front-back direction and a depth direction perpendicular to the front-back direction and the up-down direction. It looks like this. The second light source 52G is fixed to a movable part of a movable member 57G fixed to the base 41. The movable part of the movable member 57G is connected to a control section (not shown), and is periodically moved in the vertical direction and the depth direction under the control of the control section. The third light source 52B is fixed to a movable portion of a movable member 57B fixed to the base 41. The movable portion of the movable member 57B is connected to a control section (not shown), and is periodically moved in the vertical direction and the depth direction under the control of this control section.

Further, the first light source 52R is electrically connected to a circuit board 59R fixed to the base 41, and receives power via the circuit board 59R. The second light source 52G is electrically connected to a circuit board 59G fixed to the base 41, and receives power via this circuit board 59G. The third light source 52B is electrically connected to a circuit board 59B fixed to the base 41, and receives power via the circuit board 59B.

Each of the circuit boards 59R, 59G, and 59B has an elastic connection portion that movably holds the light source. FIG. 21 is a front view schematically showing a part of such a circuit board 59R. Note that since the circuit boards 59G and 59B have the same configuration as the circuit board 59R, a description of the circuit boards 59G and 59B will be omitted.

As shown in FIG. 21, a circular hole 90 is formed in the circuit board 59R. A conductive layer 94 is formed on one side and the other side with the circular hole 90 in between. These conductive layers 94 are electrically connected via a plate-shaped conductive member 91. This conductive member 91 has a pair of flat plate portions 92 located outside the circular hole 90 and a pair of elastic connection portions 93 located inside the circular hole 90. A flat plate portion 92 located on one side of the circular hole 90 is fixed to a conductive layer 94 located on one side of the circular hole 90 . A flat plate portion 92 located on the other side of the circular hole 90 is fixed to a conductive layer 94 located on the other side of the circular hole 90 .

The pair of elastic connection parts 93 are generally formed into a substantially circular shape, and the diameter of the circle formed by the pair of elastic connection parts 93 is made smaller than the diameter of the terminal of the light source 52R. Therefore, by fitting the terminal of the light source 52R inside the circle formed by the elastic connection part 93, the light source 52R and the elastic connection part 93 are electrically connected, and the light source 52R is movable by the elastic connection part 93. is maintained. With such a configuration, the light source 52R can also be moved as the movable portion of the movable member 57R is actively moved.

As shown in FIG. 20, the first collimating lens 53R is arranged above the first light source 52R, and collimates the laser beam emitted from the first light source 52R in the fast axis direction and the slow axis direction. The second collimating lens 53G is arranged behind the second light source 52G, and collimates the laser beam emitted from the second light source 52G in the fast axis direction and the slow axis direction. The third collimating lens 53B is arranged behind the third light source 52B, and collimates the laser beam emitted from the third light source 52B in the fast axis direction and the slow axis direction. These collimating lenses 53R, 53G, and 53B are each fixed to the case 40 by a structure not shown.

The first phase modulation element 54R is arranged above the first collimating lens 53R, and is fixed to the base 41 by a structure not shown. Further, the first phase modulation element 54R is arranged at an angle of about 45 degrees with respect to the front-rear direction and the up-down direction. Therefore, the red laser light emitted from the first collimating lens 53R is incident on the first phase modulation element 54R, is diffracted, and is also turned approximately 90 degrees and emitted toward the combining optical system 55 located in front. do.

The second phase modulation element 54G is arranged behind the second collimator lens 53G, and is fixed to the base 41 by a structure not shown. Further, the second phase modulation element 54G is arranged at an angle of about 45 degrees in the opposite direction to the first phase modulation element 54R with respect to the front-rear direction and the up-down direction. Therefore, the green laser light emitted from the second collimating lens 53G is incident on the second phase modulation element 54G, is diffracted, and is also turned approximately 90 degrees and emitted toward the combining optical system 55 located above. do.

The third phase modulation element 54B is arranged behind the third collimating lens 53B, and is fixed to the base 41 by a structure not shown. Further, the third phase modulation element 54B is arranged to be inclined at approximately 45° in the opposite direction to the first phase modulation element 54R with respect to the front-rear direction and the up-down direction. Therefore, the blue laser light emitted from the third collimating lens 53B is incident on the third phase modulation element 54B, is diffracted, and is also turned approximately 90 degrees and emitted toward the combining optical system 55 located above. do.

The combining optical system 55 includes a first optical element 55f and a second optical element 55s. The first optical element 55f is arranged in front of the first phase modulation element 54R and above the second phase modulation element 54G, and is inclined at approximately 45 degrees in the same direction as the first phase modulation element 54R with respect to the front-back direction and the up-down direction. It is placed in the same state. The first optical element 55f is, for example, a wavelength selection filter in which an oxide film is laminated on a glass substrate, and transmits light with a wavelength longer than a predetermined wavelength and reflects light with a wavelength shorter than the predetermined wavelength. The type and thickness of the oxide film are adjusted as follows. In this embodiment, the first optical element 55f is configured to transmit red light with a wavelength of 638 nm emitted from the first light source 52R and reflect green light with a wavelength of 515 nm emitted from the second light source 52G.

The second optical element 55s is arranged in front of the first optical element 55f and above the third phase modulation element 54B, and is inclined at approximately 45 degrees in the same direction as the first phase modulation element 54R with respect to the front-rear direction and the up-down direction. placed in the state. The second optical element 55s is a wavelength selection filter like the first optical element. In this embodiment, the second optical element 55s transmits red light with a wavelength of 638 nm emitted from the first light source 52R and green light with a wavelength of 515 nm emitted from the second light source 52G, and transmits the red light with a wavelength of 445 nm emitted from the third light source 52B. configured to reflect blue light.

Next, the configurations of the first phase modulation element 54R, second phase modulation element 54G, and third phase modulation element 54B will be described in detail.

In this embodiment, the phase modulation elements 54R, 54G, and 54B have the same configuration. Therefore, only the first phase modulation element 54R will be described in detail below, and the description of the second phase modulation element 54G and third phase modulation element 54B will be omitted as appropriate.

The first phase modulation element 54R of this embodiment has the same configuration as the first phase modulation element 54R of the first embodiment. However, the outer shape of the first phase modulation element 54R when viewed from the front is different from the outer shape of the first phase modulation element 54R of the first embodiment when viewed from the front. FIG. 22 is a front view schematically showing the first phase modulation element 54R of this embodiment. As shown in FIG. 22, the first phase modulation element 54R is formed into a substantially rectangular shape when viewed from the front. Like the first phase modulation element 54R of the first embodiment, this first phase modulation element 54R is composed of a plurality of modulation parts MP divided into a matrix, and each of the modulation parts MP is arranged in a matrix. Contains multiple dots. In addition, in FIG. 22, the circle shown by a solid line and the circle shown by a broken line indicate the incident spot SR of the red laser beam that enters the incident surface of the first phase modulation element 54R. This incident spot will be explained in detail later.

Similar to the first phase modulation element 54R, the second phase modulation element 54G and the third phase modulation element 54B are each composed of a plurality of modulation sections MP divided into a matrix shape, and each of the modulation sections MP is divided into a matrix shape. Contains multiple dots arranged in .

In this embodiment, each of the modulation parts MP of the first phase modulation element 54R has the same phase modulation pattern corresponding to red laser light. This phase modulation pattern is such that the shape of the light distribution pattern of the emitted light is the same as the light distribution pattern PL of the low beam shown in FIG. 5(A). Moreover, each of the modulation parts MP of the second phase modulation element 54G has the same phase modulation pattern corresponding to the green laser light. This phase modulation pattern is such that the shape of the light distribution pattern of the emitted light is the same as the light distribution pattern PL of the low beam. Furthermore, each of the modulation sections MP of the third phase modulation element 54B has the same phase modulation pattern corresponding to blue laser light. This phase modulation pattern is such that the shape of the light distribution pattern of the emitted light is the same as the light distribution pattern PL of the low beam. Therefore, the shape of the light distribution pattern of the light emitted from the phase modulation elements 54R, 54G, and 54B is generally the same shape as the light distribution pattern of the low beam.

Next, light emission from the vehicle headlamp 1 will be explained. In this embodiment, a case where a low beam is emitted from the vehicle headlamp 1 will be described.

When power is supplied from a power source (not shown) to the first light source 52R via the circuit board 59R, the first light source 52R generates red laser light, and this red laser light is emitted upward. As described above, the first light source 52R is fixed to the movable member 57R, and the movable member 57R periodically moves in the front-back direction and the depth direction. Therefore, the red laser light emitted from the first light source 52R also periodically moves in the front-rear direction and the depth direction. Such red laser light is collimated by the first collimating lens 53R arranged above, and enters the phase modulation element 54R.

When power is supplied from a power supply (not shown) to the second light source 52G via the circuit board 59G, the second light source 52G generates green laser light, and this green laser light is emitted backward. As described above, the second light source 52G is fixed to the movable member 57G, and the movable member 57G periodically moves in the vertical direction and the depth direction. Therefore, the green laser light emitted from the second light source 52G also periodically moves in the vertical direction and the depth direction. Such green laser light is collimated by a second collimator lens 53G arranged at the rear, and enters a phase modulation element 54G.

When power is supplied from a power supply (not shown) to the third light source 52B via the circuit board 59B, the third light source 52B generates blue laser light, and this blue laser light is emitted backward. As described above, the third light source 52B is fixed to the movable member 57B, and the movable member 57B periodically moves in the vertical direction and the depth direction. Therefore, the blue laser light emitted from the third light source 52B also periodically moves in the vertical direction and the depth direction. Such blue laser light is collimated by the third collimating lens 53B placed at the rear, and enters the phase modulation element 54B.

The red laser beam incident on the phase modulation element 54R is reflected by the phase modulation element 54R and is emitted forward from the phase modulation element 54R. As mentioned above, the movable member 57R moves periodically in two directions. Therefore, as shown in FIG. 22, the incident spot SR of the red laser beam moves periodically in two directions on the incident surface of the phase modulation element 54R. In this way, the movable member 57R functions as a spot moving section that moves the incident spot SR relative to the phase modulation element 54R. Note that the solid line circle in FIG. 22 indicates the position of the incident spot SR before movement, and the four broken line circles indicate the position of the incident spot SR after movement.

As shown in FIG. 22, the incident spot SR includes at least one modulation section MPR regardless of the position of the incident spot SR on the incident surface of the phase modulation element 54R. Therefore, the light distribution pattern of the red laser light emitted from the phase modulation element 54R is the same regardless of whether before, during, or after the relative movement of the incident spot SR. In this way, red laser light having a predetermined light distribution pattern is emitted forward from the phase modulation element 54R. Hereinafter, the red laser light emitted from the phase modulation element 54R will be referred to as first light DLR. As described above, the shape of the light distribution pattern of the first light DLR is approximately the same shape as the light distribution pattern PL of the low beam. In this embodiment, the moving distance of the incident spot SR on the incident surface of the phase modulating element 54R is set to be equal to or larger than the diameter of the incident spot SR. Note that although the incident spot is shown as a circle in FIG. 22, the outer shape of the incident spot is not limited to a circle, and may be, for example, an ellipse.

The green laser light incident on the phase modulation element 54G is reflected by the phase modulation element 54G and is emitted upward from the phase modulation element 54G. As mentioned above, the movable member 57G moves periodically in two directions. Therefore, the incident spot of the green laser beam moves periodically in two directions on the incident surface of the phase modulation element 54G. In this way, the movable member 57G functions as a spot moving unit that moves the incident spot of the green laser beam relative to the phase modulation element 54G.

Similar to the incident spot SR of the red laser beam, the incident spot of the green laser beam includes at least one modulation section MP. Therefore, the light distribution pattern of the green laser light emitted from the phase modulation element 54G is the same regardless of whether before, during, or after the relative movement of the incident spot of the green laser light. In this way, green light having a predetermined light distribution pattern is emitted upward from the phase modulation element 54G. Hereinafter, the green light emitted from the phase modulation element 54G will be referred to as second light DLG. As described above, the shape of the light distribution pattern of the second light DLG is the same as the light distribution pattern of the low beam. In this embodiment, the moving distance of the incident spot of the green laser beam on the incident surface of the phase modulation element 54G is set to be equal to or larger than the diameter of the incident spot.

The blue laser light incident on the phase modulation element 54B is reflected by the phase modulation element 54B and exits upward from the phase modulation element 54B. As mentioned above, the movable member 57B moves periodically in two directions. Therefore, the incident spot of the blue laser beam moves periodically in two directions on the incident surface of the phase modulation element 54B. In this way, the movable member 57B functions as a spot moving unit that moves the incident spot of the blue laser light relative to the phase modulation element 54G.

Similar to the incident spot SR of the red laser beam, the incident spot of the blue laser beam includes at least one modulation section MP. Therefore, the light distribution pattern of the blue laser light emitted from the phase modulation element 54B is the same regardless of whether before, during, or after the relative movement of the incident spot of the blue laser light. In this way, blue light having a predetermined light distribution pattern is emitted upward from the phase modulation element 54B. Hereinafter, the blue light emitted from the phase modulation element 54B will be referred to as third light DLB. As described above, the shape of the light distribution pattern of the third light DLB is the same as the light distribution pattern of the low beam. In addition, in this embodiment, the moving distance of the incident spot of the blue laser beam on the incident surface of the phase modulation element 54B is set to be greater than or equal to the diameter of the incident spot.

A first optical element 55f of the combining optical system 55 is arranged in front of the first phase modulation element 54R. As described above, the first optical element 55f is configured to transmit red light. Therefore, the first light DLR emitted from the first phase modulation element passes through the first optical element 55f and propagates forward. Furthermore, a first optical element 55f is arranged above the second phase modulation element 54G. As described above, the first optical element 55f is configured to reflect green light and is inclined at approximately 45 degrees with respect to the front-rear direction and the up-down direction, so that the first optical element 55f does not emit light from the second phase modulation element 54G. The second light DLG is reflected by the first optical element 55f and propagates forward. That is, the first combined light LS1 consisting of the first light DLR and the second light DLG propagates toward the second optical element 55s.

A second optical element 55s of the synthetic optical system 55 is arranged in front of the first optical element 55f. As described above, the second optical element 55s is configured to transmit red light and green light. Therefore, the first combined light LS1 passes through the second optical element 55s. Furthermore, a second optical element 55s is arranged above the third phase modulation element 54B. As described above, the second optical element 55s is configured to reflect blue light, and is inclined at approximately 45 degrees with respect to the front-rear direction and the up-down direction, so that the blue light is emitted from the third phase modulation element 54B. The third light DLB is reflected by the second optical element 55s and propagates forward. That is, the second combined light LS2 consisting of the first light DLR, the second light DLG, and the third light DLB propagates toward the opening 40H of the case 40 and exits from the opening 40H.

As described above, the lights DLR, DLG, and DLB forming the second combined light all have a light distribution pattern in the shape of a low beam. Therefore, when the second combined light LS2 emitted from the aperture 40H propagates forward by a predetermined distance, the lights DLR, DLG, and DLB overlap, and the low beam, which is white light, is arranged as shown in FIG. 5(A). A light pattern PL may be formed.

Here, in the phase modulation element in the vehicle lamp described in Patent Document 1, when light is concentrated and incident on a specific area, the temperature in that area becomes high and the characteristics of the phase modulation element change. There is a concern that the light distribution pattern will not be formed.

Therefore, the vehicle headlamp 1 of this embodiment as a fourth aspect includes light sources 52R, 52G, 52B, phase modulation elements 54R, 54G, 54B, and movable members 57R, 57G, 57B as spot moving parts. Equipped with. The light sources 52R, 52G, and 52B emit light of predetermined wavelengths. The phase modulation elements 54R, 54G, and 54B diffract the light emitted from the light sources 52R, 52G, and 52B, thereby forming the light into a predetermined light distribution pattern. The movable members 57R, 57G, 57B move the light incident spots on the phase modulation elements 54R, 54G, 54B relative to the phase modulation elements 54R, 54G, 54B. The phase modulation elements 54R, 54G, and 54B are divided into modulation parts MP that form a light distribution pattern, and at least one modulation part MP is included in the incident spot. Therefore, according to the vehicle headlamp 1 in this embodiment, the same light distribution pattern can be formed even if the incident spot moves. Further, according to the vehicle headlamp 1 in this embodiment, since the incident spot moves relative to the phase modulation elements 54R, 54G, 54B, light is directed to specific areas of the phase modulation elements 54R, 54G, 54B. It may be possible to prevent the light from being incident in a concentrated manner, and it may be possible to prevent the specific region from increasing in temperature. Therefore, the occurrence of areas where it is difficult to form a predetermined light distribution pattern is suppressed, and it becomes easier to obtain a desired light distribution pattern.

Further, as described above, according to the vehicle headlamp 1 in this embodiment as the fourth aspect, the distance that the incident spot of the red laser beam moves on the incident surface of the phase modulation element 54R is It is assumed that the diameter is greater than or equal to the diameter of Similarly, the distance that the incident spot of the green laser beam moves on the incident surface of the phase modulation element 54G is set to be greater than or equal to the diameter of the incident spot. Similarly, the distance that the incident spot of the blue laser beam moves on the incident surface of the phase modulation element 54B is set to be greater than or equal to the diameter of the incident spot. Therefore, as shown in FIG. 22, the incident spot after the movement and the incident spot before the movement can be prevented from overlapping, and it is effective to prevent specific regions of the phase modulation elements 54R, 54G, and 54B from becoming heated. can be suppressed.

Further, as described above, according to the vehicle headlamp 1 in this embodiment as the fourth aspect, the incident spot of the red laser beam, the incident spot of the green laser beam, and the incident spot of the blue laser beam are respectively Move regularly. Therefore, it can be effectively suppressed that light enters specific regions of the phase modulation elements 54R, 54G, and 54B for a long period of time, and the temperature of the specific regions of the phase modulation elements 54R, 54G, and 54B is prevented from increasing. can be more suppressed. Note that the cycle of moving the incident spot can be changed as appropriate in consideration of the heat resistance of the phase modulation elements 54R, 54G, and 54B. For example, the incident spot may move in two directions at a cycle of 1 second, or this cycle may be set at a cycle of 1 minute.

Further, as described above, according to the vehicle headlamp 1 in this embodiment as the fourth aspect, the incident spot is moved in two directions by the movable members 57R, 57G, and 57B, which are spot moving mechanisms. Therefore, compared to the case where the incident spot moves only in one direction, the incident spot can move over a wider range on the incident surface of the phase modulation element. Therefore, it can be effectively suppressed that a specific region becomes high in temperature. However, the incident spot may move only in one direction. Further, the incident spot may move in three or more directions. When the incident spot moves in three or more directions, the incident surface of the phase modulation element can be moved over a wider range than when the incident spot moves in two directions. For this reason, increase in temperature in a specific region can be more effectively suppressed.

Further, as described above, according to the vehicle headlamp 1 in this embodiment as the fourth aspect, the light sources 52R, 52G, 52B are held by the elastic connection portions 93 of the circuit boards 59B, 59G, 59B. Therefore, it is possible to move only the light sources 52R, 52G, and 52B.

Further, as described above, according to the vehicle headlamp 1 in this embodiment, the phase modulation elements 54R, 54G, and 54B are provided for each of the light sources 52R, 52G, and 52B. That is, since the phase modulating elements 54R, 54G, 54B are provided in one-to-one correspondence with the light sources 52R, 52G, 52B, it may be easy to adjust the light distribution pattern for each light source.

(12th embodiment)
Next, a twelfth embodiment as the fourth aspect of the present invention will be described. Note that components that are the same or equivalent to those in the eleventh embodiment are given the same reference numerals and redundant explanations will be omitted, unless otherwise specified.

FIG. 23 is a diagram similar to FIG. 20 showing a part of the lamp unit 20 of the vehicle headlamp 1 in the twelfth embodiment as the fourth aspect of the present invention. As shown in FIG. 23, the lamp unit 20 according to the present embodiment is different from the lamp unit 20 according to the eleventh embodiment in that the light sources 52R, 52G, and 52B are attached to the base 41 of the case 40 via elastic members. It differs from Specifically, the first light source 52R is attached to the base 41 via a pair of elastic members 157R, and the second light source 52G is attached to the base 41 via a pair of elastic members 157G. The third light source 52B is attached to the base 41 via a pair of elastic members 157B. Note that these elastic members 157R, 157G, and 157B may be springs, for example.

According to such a configuration, since the light sources 52R, 52G, 52B are attached to the base 41 via the elastic members 157R, 157G, 157B, the light sources 52R, 52G, 52B are vibrates passively. Therefore, as the light sources 52R, 52G, and 52B vibrate, the incident spots move relative to the phase modulation elements 54R, 54G, and 54B. Therefore, similarly to the eleventh embodiment, light is prevented from being incident on a specific region of the phase modulation element in a concentrated manner, making it easier to obtain a desired light distribution pattern.

(13th embodiment)
Next, a thirteenth embodiment as a fourth aspect of the present invention will be described. Note that components that are the same or equivalent to those in the eleventh embodiment are given the same reference numerals and redundant explanations will be omitted, unless otherwise specified.

FIG. 24 is a diagram similar to FIG. 20 showing a part of the lamp unit 20 of the vehicle headlamp 1 in the thirteenth embodiment as the fourth aspect of the present invention. Note that in FIG. 24, a part of the case 40 is omitted for ease of understanding. As shown in FIG. 24, in the lamp unit 20 according to the thirteenth embodiment, the number of phase modulation elements in the optical system unit 50 is one, but the number of phase modulation elements in the optical system unit 50 is three. This is different from the lamp unit 20 in the eleventh and twelfth embodiments. The configuration of the lamp unit 20 in the thirteenth embodiment will be described below.

In this embodiment, the first light source 52R is arranged to emit red laser light upward, the second light source 52G is arranged to emit green laser light backward, and the third light source 52B is arranged to emit blue laser light. It is arranged so that it emits to the rear.

The first light source 52R is fixed to a movable part of a movable member 57R fixed to the base 41. In this embodiment, the movable portion of the movable member 57R periodically moves in the front-rear direction and the depth direction. Further, the first light source 52R is held by the elastic connection portion of the circuit board 59R, similarly to the first embodiment. Therefore, the light source 52R can move in the front-rear direction and the depth direction as the movable portion of the movable member 57R moves.

The second light source 52G is fixed to a movable part of a movable member 57G fixed to the base 41. In this embodiment, the movable portion of the movable member 57G periodically moves in the vertical direction and the depth direction. Further, the second light source 52G is held by the elastic connection portion of the circuit board 59G, similarly to the first embodiment. Therefore, the light source 52G can move in the vertical direction and the depth direction as the movable portion of the movable member 57G moves.

The third light source 52B is fixed to a movable portion of a movable member 57B fixed to the base 41. In this embodiment, the movable portion of the movable member 57B periodically moves in the vertical direction and the depth direction. Further, the third light source 52B is held by the elastic connection portion of the circuit board 59B, similarly to the first embodiment. Therefore, the light source 52B can move in the vertical direction and the depth direction as the movable portion of the movable member 57B moves.

The circuit boards 59R, 59G, and 59B are connected to a control section (not shown). This control section prevents light from the light sources 52G and 52B from being emitted while the light source 52R is emitting red laser light, and prevents light from the light sources 52R and 52B from emitting while the light source 52G is emitting green laser light. is not emitted, and while the light source 52B is emitting blue laser light, the light from the light sources 52R and 52G is not emitted. That is, in this embodiment, the red laser light from the light source 52R, the green laser light from the light source 52G, and the blue laser light from the light source 52B are switched and emitted at a predetermined cycle based on the control of the control section. .

Note that, similarly to the first and second embodiments, the laser beams emitted from the light sources 52R, 52G, and 52B are collimated by collimating lenses 53R, 53G, and 53B.

A combining optical system 55 is provided above the collimating lens 53R and behind the collimating lenses 53G and 53B. That is, a first optical element 55f is provided above the collimating lens 53R and behind the collimating lens 53G, and a second optical element 55s is provided above the first optical element 55f and behind the collimating lens 53B. These optical elements 55f and 55s are arranged at an angle of approximately 45 degrees in the front-back direction and the up-down direction.

One phase modulation element 54S is provided above the second optical element 55s. This phase modulation element 54S is arranged at a position where the red laser beam, green laser beam, and blue laser beam that have passed through the combining optical system 55 can be incident. The phase modulation element 54S in this embodiment is, for example, a reflective LCOS. This phase modulation element 54S is arranged at an angle of about 45 degrees in the front-rear direction and the up-down direction, and the direction of the inclination is opposite to that of the optical elements 55f and 55s.

Similar to the eleventh and twelfth embodiments, the phase modulation element 54S is divided into a plurality of modulation sections, and each modulation section forms a light distribution pattern having approximately the same shape as the low beam light distribution pattern. obtain. In this embodiment, the entire area of at least one modulation section is included in each of the incident spots of the red laser beam, the green laser beam, and the blue laser beam.

Next, light emission from the lamp unit 20 of this embodiment will be explained.

As described above, the red laser light from the light source 52R, the green laser light from the light source 52G, and the blue laser light from the light source 52B are switched and emitted at a predetermined cycle. For example, first, red laser light is emitted from the first light source 52R for a predetermined period of time. Note that when a plurality of first light sources 52R that emit red laser light are provided, red laser light is emitted from the plurality of first light sources 52R for a predetermined period of time. During this time, the laser beams from the light sources 52G and 52B are not emitted. This red laser light is collimated by the collimating lens 53R, passes through the combining optical system 55, and enters the phase modulation element 54S. As described above, since the first light source 52R moves in two directions, the incident spot of the red laser beam also moves in two directions on the incident surface of the phase modulation element 54S.

As described above, since at least one modulation section is included in the incident spot of the red laser beam, the first light having a light distribution pattern approximately the same shape as the light distribution pattern of the low beam is emitted from the phase modulation element 54S. DLR fires forward.

After a predetermined period of time has elapsed, the light source 52R stops emitting light, and the light source 52G emits green laser light for a predetermined period of time. Note that when a plurality of second light sources 52G that emit green laser light are provided, the green laser light is emitted from the plurality of second light sources 52G for a predetermined period of time. This green laser light is collimated by a collimating lens 53G, passes through a combining optical system 55, and enters a phase modulation element 54S. As described above, since the first light source 52R moves in two directions, the incident spot of the green laser beam also moves in two directions on the incident surface of the phase modulation element 54S.

As described above, since at least one modulation section is included in the incident spot of the green laser beam, the second light having a light distribution pattern approximately the same shape as the light distribution pattern of the low beam is emitted from the phase modulation element 54S. DLG fires forward.

After a further predetermined period of time has elapsed, the red laser beam from the light source 52G is not emitted, and the blue laser beam is emitted from the light source 52B for a predetermined period of time. Note that when a plurality of third light sources 52B that emit blue laser light are provided, the blue laser light is emitted from the plurality of third light sources 52B for a predetermined period of time. After being collimated by the collimating lens 53B, this blue laser light passes through the combining optical system 55 and enters the phase modulation element 54S. As described above, since the third light source 52B moves in two directions, the incident spot of the blue laser beam also moves in two directions on the incident surface of the phase modulation element 54S.

As described above, since at least one modulation section is included in the incident spot of the blue laser beam, the third light having a light distribution pattern approximately the same shape as the light distribution pattern of the low beam is emitted from the phase modulation element 54S. DLB fires forward.

The light emission cycle as described above is repeated at a predetermined period. As described above, if the period of this emission cycle is shorter than the time resolution of human vision, an afterimage effect occurs, and the person may perceive that different colors of light are being combined and irradiated. Therefore, by making the above-mentioned period shorter than the human time resolution, a person can receive white light, which is a combination of red light DLR, green light DLG, and blue light DLB, from the lamp unit 20. It can be recognized that it is being emitted.

Note that, as described above, the temporal resolution of human vision is approximately 1/30 s, so the period is preferably 1/30 s or less, and more preferably 1/60 s or less. Note that even if the period is greater than 1/30 s, the afterimage effect may occur. For example, even if the period is 1/15 seconds, the afterimage effect may occur.

According to the vehicle headlamp 1 in this embodiment, as in the eleventh and twelfth embodiments, the incident spot moves on the incident surface of the phase modulation element, so that light is concentrated on a specific area of the phase modulation element. This makes it easier to obtain a desired light distribution pattern such as a low beam.

Further, according to the vehicle headlamp 1 in this embodiment, unlike the eleventh and twelfth embodiments in which a phase modulation element is provided for each light source, the number of phase modulation elements constituting the optical system unit 50 is reduced. Since it can be made into one, the number of parts can be reduced and costs can be reduced.

In this embodiment, an example has been described in which the light sources 52R, 52G, and 52B switch the light emission, but at least two of the light sources 52R, 52G, and 52B may switch the light emission at a predetermined period. For example, the thirteenth embodiment may be modified so that only the light sources 52R and 52G switch light emission at a predetermined period. In this modification, an optical system is constructed from two phase modulation elements: a phase modulation element that receives red laser light and green laser light from light sources 52R and 52G, and a phase modulation element 54B that receives blue laser light from light source 52B. Unit 50 may be configured. That is, also in this modification, the number of phase modulation elements can be reduced compared to the eleventh and twelfth embodiments.

Note that although the fourth aspect of the present invention has been described using the eleventh to thirteenth embodiments as examples, the fourth aspect of the present invention is not limited to these.

For example, in the eleventh to thirteenth embodiments as the fourth aspect, an example will be described in which the phase modulation element is fixed to a base and the light source is moved to move the incident spot on the entrance surface of the phase modulation element. did. However, the light source may be fixed to the case 40 and the phase modulation element may be moved relative to the light source. That is, a spot moving section that moves the phase modulation element may be configured. However, since the light source tends to be lighter than the phase modulation element, by configuring a spot moving section that moves the light source as in the 11th to 13th embodiments, the incident spot can be moved onto the entrance surface of the phase modulation element. It can be easier to move.

Further, in the eleventh to thirteenth embodiments as the fourth aspect, an example is described in which an LCOS is used as the phase modulation element, but a diffraction grating may be used as the phase modulation element. However, as described above, LCOS is a phase modulation element that produces a refractive index difference in a liquid crystal layer by changing the orientation pattern of liquid crystal molecules. In such an LCOS, when the temperature of a specific region increases, the change in the alignment pattern in that region becomes large, so there is a big concern that it will be difficult to obtain a desired light distribution pattern. However, according to the eleventh to thirteenth embodiments, it is suppressed that light is concentrated and incident on a specific area of the LCOS, and a large change in the light distribution pattern is effectively suppressed. It becomes easier to obtain a light distribution pattern. Further, a GLV may be used as the phase modulation element.

Further, in the eleventh to thirteenth embodiments as the fourth aspect, an example in which the phase modulation element is a reflective type has been described, but the phase modulation element may be a transmission type.

Furthermore, in the eleventh to thirteenth embodiments as the fourth aspect, an example has been described in which the moving distance of the incident spot is greater than or equal to the diameter of the incident spot, but the moving distance of the incident spot is greater than the diameter of the incident spot. It can be small. For example, the distance over which the incident spot moves relative to each other may be greater than or equal to the radius of the incident spot. The power distribution of light in an incident spot is generally not uniform, and for example, a predetermined region such as the central region of the incident spot tends to have a peak power region. Considering the size of this peak area, if the distance that the incident spot moves relative to the phase modulation element is equal to or greater than the radius of the incident spot, it is possible to suppress the peak areas from overlapping before and after the relative movement. , temperature increase in a specific region of the phase modulation element can be effectively suppressed. However, if the moving distance of the incident spot is smaller than the diameter of the incident spot, a region may occur where the incident spot before movement and the incident spot after movement overlap, and there is a risk that the temperature increase will increase in this region. For this reason, it is more preferable that the moving distance of the incident spot is equal to or greater than the diameter of the incident spot.

Further, in the eleventh to thirteenth embodiments as the fourth aspect, an example in which the incident spot moves periodically has been described, but the incident spot may move irregularly. However, if the incident spot moves irregularly, the period during which the incident spot remains in the same area may become long, and there is a possibility that the temperature rise in this area will be large. For this reason, it is preferable that the incident spot moves periodically.

Further, in the eleventh to thirteenth embodiments as the fourth aspect, an example has been described in which a vehicle headlamp as a vehicle lamp includes three light sources 52R, 52G, and 52B. It is sufficient to include one light source and one phase modulation element that receives light from the light source. However, as in the eleventh to thirteenth embodiments, when the vehicle lamp includes a plurality of light sources that emit light of different wavelengths, it is possible to generate light of a desired color such as white light.

Further, in the eleventh to thirteenth embodiments as the fourth aspect, the vehicle headlamp 1 as the vehicle lamp emits a low beam, but the vehicle lamp as the fourth aspect emits a low beam. The light used is not limited to low beam. For example, a vehicle lamp in another embodiment may be configured to emit a low beam and a sign recognition light OHS, as shown in FIG. 5(A). Further, a vehicle lamp in another embodiment may be configured to emit light with a high beam light distribution pattern PH as shown in FIG. 5(B). In yet another embodiment, the vehicle lamp of the present invention may be used as a component of an image. In such a case, the direction of light emitted from the vehicle lamp and the mounting position of the vehicle lamp in the vehicle are not particularly limited.

According to a first aspect of the present invention, there is provided a vehicle lamp that can form a predetermined light distribution pattern while suppressing a decrease in energy efficiency. According to a third aspect of the present invention, there is provided a vehicle light that can suppress increase in the number of parts while suppressing the increase in the number of parts. According to the present invention, a vehicle lamp with which a desired light distribution pattern can be easily obtained is provided, and can be used in the field of vehicle lamps such as automobiles.

1...Vehicle headlights (vehicle lights)
10... Housing 20... Lamp unit 50... Optical system unit 52R... First light source 52G... Second light source 52B... Third light source 54... Phase modulation element assembly 54R ...First phase modulation element 54G...Second phase modulation element 54B...Third phase modulation element 54S...Phase modulation element 55...Synthesizing optical system 57R, 57G, 57B...Movable member (Spot moving part)
59R, 59G, 59B...Circuit board 93...Elastic connection part 155...Light guide optical system 157R, 157G, 157G...Elastic member EF, EFR, EFG, EFB...Incidence surface LAR, LAG , LAB... Long axis MPR, MPG, MPB, MP... Modulation section SR, SG, SB... Incident spot H54... Vertical width of phase modulation element WR... First phase modulation element Lateral width WG...Lateral width WB of the second phase modulation element...Lateral width WS of the third phase modulation element...Lateral width of the phase modulation element

Claims (24)

a light source that emits light;
a phase modulation element having at least one modulation section that diffracts the light from the light source to make the light into a predetermined light distribution pattern;
Equipped with
An incident surface on which the light enters the phase modulation element and an incident spot of the light on the phase modulation element have a shape that is longer in a predetermined direction than in other directions,
The incident spot has a size that can include at least one of the modulation parts,
A vehicle lamp characterized in that a longitudinal direction of the incident surface of the phase modulation element and a longitudinal direction of the incident spot are non-perpendicular. 2. The vehicular lamp according to claim 1, wherein a longitudinal direction of the incident surface of the phase modulation element and a longitudinal direction of the incident spot are parallel to each other. 3. The vehicle lamp according to claim 1, wherein the longitudinal direction of the incident surface of the phase modulation element is a horizontal direction. having a plurality of the light sources;
The phase modulation element is provided for each of the plurality of light sources,
4. At least one phase modulation element is connected to at least one other phase modulation element and is formed integrally with the other phase modulation element. Vehicle lights listed. having a plurality of the light sources;
The phase modulation element is provided for each of the plurality of light sources,
at least two of the phase modulation elements are arranged adjacently in parallel in a specific direction,
4. The vehicle lamp according to claim 1, wherein the longitudinal direction of each of the incident surfaces of the at least two phase modulating elements is parallel to the specific direction. multiple light sources that emit light of different wavelengths,
at least one phase modulation element that diffracts the light emitted from each of the plurality of light sources to make each of the plurality of lights a predetermined light distribution pattern;
Equipped with
A vehicular lamp characterized in that the sizes of incident spots of at least two lights of different wavelengths on the phase modulation element are different from each other. The vehicular lamp according to claim 6, wherein the incident spots of the plurality of lights all have different sizes. The vehicular lamp according to claim 6 or 7, wherein at least two of the lights are incident on a common phase modulation element. 9. The vehicle lamp according to claim 6, wherein the phase modulation element is an LCOS (Liquid Crystal On Silicon). 10. The vehicle according to claim 6, wherein among the at least two lights whose incident spot sizes are different from each other, the incident spot of the light having a larger total luminous flux is made larger. Light equipment. Any one of claims 6 to 9, wherein among the at least two lights whose incident spot sizes are different from each other, the incident spot of the light is made smaller as the light has a longer optical path length to the phase modulation element. Vehicle lighting equipment described in section. According to any one of claims 6 to 9, the light having a smaller incident spot among the at least two lights having different incident spot sizes is emitted from more of the light sources. Vehicle lights listed. The vehicular lamp according to any one of claims 7 to 9, wherein the incident spot of the light having a longer wavelength is smaller. a light source that emits light of a predetermined wavelength;
a phase modulation element that diffracts the light emitted from the light source to form a predetermined light distribution pattern;
a spot moving unit that moves an incident spot of the light on the phase modulation element relative to the phase modulation element;
Equipped with
The phase modulation element is divided into modulation sections that form the light distribution pattern,
A vehicular lamp characterized in that at least one of the modulation sections is included in the incident spot. 15. The vehicular lamp according to claim 14, wherein a distance over which the incident spot moves relative to each other is greater than or equal to a radius of the incident spot. The vehicular lamp according to claim 15, wherein the distance is greater than or equal to the diameter of the incident spot. 17. The vehicular lamp according to claim 14, wherein the incident spot moves relative to each other periodically. 18. The vehicle lamp according to claim 14, wherein the spot moving unit relatively moves the incident spot in two or more directions. 19. The vehicle lamp according to claim 14, wherein the phase modulation element is an LCOS (Liquid Crystal On Silicon). The vehicle lamp according to any one of claims 14 to 19, wherein the spot moving section moves the light source. further comprising a circuit board that supplies power to the light source,
21. The vehicle lamp according to claim 20, wherein the light source moves relative to the circuit board. The vehicular lamp according to claim 21, wherein the circuit board includes an elastic connection part to which the light source is electrically connected. comprising a plurality of the light sources that emit light of mutually different wavelengths,
23. The vehicle lamp according to claim 14, wherein the phase modulation element is provided for each of the plurality of light sources. comprising a plurality of the light sources that emit light of mutually different wavelengths,
At least two of the plurality of light sources switch the emission of the light at a predetermined period,
23. The vehicle lamp according to claim 14, wherein the plurality of lights emitted from the at least two light sources enter the common phase modulation element.

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