WO2020039964A1

WO2020039964A1 - Vehicle lamp

Info

Publication number: WO2020039964A1
Application number: PCT/JP2019/031394
Authority: WO
Inventors: 和也本橋; 壮宜鬼頭
Original assignee: 株式会社小糸製作所
Priority date: 2018-08-21
Filing date: 2019-08-08
Publication date: 2020-02-27
Also published as: JP7285260B2; JPWO2020039964A1; CN112368510B; CN112368510A

Abstract

A vehicle headlamp (1) serving as a vehicle lamp comprises: light sources (52R, 52G, 52B) that emit beams of light of mutually different wavelengths; phase modulation elements (54R, 54G, 54B) in which the beams of light emitted from each of the light sources (52R, 52G, 52B) are diffracted, thereby imparting each of the plurality of beams of light with a prescribed light distribution pattern; and a projection lens (80) that adjusts the divergence angle of beams of light DLR, DLG, DLB emitted from the phase modulation elements (54R, 54G, 54B). Of the beams of light DLR, DLG, DLB imparted with the prescribed light distribution pattern by the phase modulation elements (54R, 54G, 54B), the beam of light DLB having the shortest wavelength is imaged at an imaging position CPB closest to the projection lens (80).

Description

Vehicle lighting

The present invention relates to a vehicle lamp, and more specifically, to a vehicle lamp having a projection lens.

構成 Vehicle headlights, which are representative of automotive headlights, are being studied for various configurations that allow emitted light to have a desired light distribution pattern. For example, Patent Literature 1 below describes that a predetermined light distribution pattern is formed using a hologram element which is a kind of a phase modulation element.

JP 2012-146621 A

By the way, in the phase modulation element described in Patent Document 1, it tends to be difficult to increase the divergence angle due to the manufacturing convenience and the properties of the phase modulation element. Therefore, when a low beam is generated via such a phase modulation element, for example, it may be preferable to separately arrange a projection lens in order to adjust the divergence angle of light emitted from the phase modulation element. However, when light is transmitted through such a projection lens, there is a concern that chromatic aberration of the projection lens may cause color fringing at the outer edge of the light.

Accordingly, it is an object of the present invention to provide a vehicle lamp having a projection lens and capable of suppressing color fringing.

In order to achieve the above object, the vehicle lamp according to the first 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, At least one phase modulation element that sets each of the plurality of lights to a predetermined light distribution pattern, and a projection lens that adjusts a divergence angle of the plurality of lights emitted from the phase modulation element, is provided by the phase modulation element. The plurality of lights having the predetermined light distribution pattern are formed such that light having a shorter wavelength forms an image closer to the projection lens.

光 Light having a short wavelength tends to be refracted more greatly when it enters a lens than light having a long wavelength. In this vehicle lamp, since light with a shorter wavelength forms an image at a position closer to the projection lens, when these lights pass through the projection lens, the outer edges of these lights can be closer to parallel to each other, and the Color bleeding can be suppressed.

In addition, in the vehicle lamp according to the first aspect, it is preferable that outer edges of the plurality of lights emitted from the projection lens are parallel to each other.

In this case, the light bleeding can be effectively suppressed.

In the vehicle lighting device according to the first aspect, each of the plurality of lights may form an image at a focal point of the projection lens.

In this case, the outer edges of the plurality of lights emitted from the projection lens are parallel to each other.

In addition, in the vehicle lamp according to the first aspect, it is preferable that outer edges of the plurality of lights emitted from the projection lens overlap each other.

In this case, the color bleeding can be more effectively suppressed.

In the vehicle lighting device according to the first aspect, it is preferable that the predetermined light distribution patterns of the plurality of lights have the same outer shape.

In this case, since the light distribution pattern of each light has the same outer shape, the outer edges of the light emitted from the projection lens can easily become parallel and can easily overlap each other.

To achieve the above object, the vehicle lamp according to the second 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. At least one phase modulation element having a plurality of light beams each having the same shape light distribution pattern, and a projection lens for adjusting a divergence angle of the plurality of light beams emitted from the phase modulation element, comprising: Among the plurality of light images formed on the focal plane passing through the focal point and perpendicular to the optical axis direction of the projection lens, the light image having a shorter wavelength is enlarged.

像 When images of light having different wavelengths overlap on the focal plane, each light enters the projection lens in a state where the outer edges of the light distribution pattern of each light overlap. In this case, due to the chromatic aberration of the projection lens, light having a shorter wavelength is refracted inward and the distance between the outer edges of the light distribution pattern of each light is widened, so that color fringing tends to occur at the outer edge of the light. On the other hand, in this vehicular lamp, of the light images formed on the focal plane, the light image having a shorter wavelength is enlarged. That is, in the focal plane, the outer edge of the image of the light having the shorter wavelength is located outside the outer edge of the image of the light having the longer wavelength, so that the light having the shorter wavelength can enter the projection lens at the outer side. Therefore, in the plurality of lights emitted from the projection lens, the outer edges of the light distribution patterns of the plurality of lights can be almost parallel, and the color blur can be suppressed.

In addition, in the vehicle lamp according to the second aspect, it is preferable that outer edges of the plurality of lights emitted from the projection lens are parallel to each other.

In this case, the color bleeding can be more effectively suppressed.

In addition, in the vehicle lamp according to the second aspect, it is preferable that outer edges of the plurality of lights emitted from the projection lens overlap each other.

In this case, the color fringing can be more effectively suppressed by overlapping the outer edges of the light.

In the vehicle lighting device according to the first and second aspects, the phase modulation element may be provided for each of the plurality of light sources.

In this case, since the phase modulation elements are provided in a one-to-one correspondence with the plurality of light sources, it is easy to form a light distribution pattern according to the light emitted from each light source.

Further, in the vehicular lamp according to the first and second aspects, at least two of the plurality of light sources switch the emission of the light from each light source at a predetermined cycle, and the at least two light sources A plurality of the lights emitted from the light are incident on the common phase modulation element, and the phase modulation element on which the light from the at least two light sources is incident changes a diffraction pattern according to a wavelength of the incident light. May be.

In this case, since the phase modulation element that receives light from at least two light sources can be a common phase modulation element, the number of phase modulation elements provided in the vehicle lamp can be reduced, and the number of parts and the cost can be reduced. Down can be realized.

In the vehicle lighting device according to the first and second aspects, it is preferable that the cycle is 1/30 s or less.

(4) When light having different wavelengths is repeatedly irradiated at a time interval shorter than the temporal resolution of human vision, a person can recognize that light combined with light of different colors is being irradiated due to an afterimage effect. The temporal resolution of human vision is approximately 1/30 s. Therefore, if the switching cycle of at least two light sources is 1/30 s or less, a person can easily recognize that the combined light of the lights of different colors is being irradiated.

In the vehicle lighting device according to the first and second embodiments, the phase modulation element may be an LCOS (Liquid Crystal On Silicon).

LCOS causes a difference in the refractive index of the liquid crystal layer by changing the arrangement of the liquid crystal molecules according to the voltage. Therefore, by adjusting the voltage applied to the LCOS, it may be possible to change the light distribution pattern of light and adjust the light imaging position.

In addition, in the vehicular lamp according to the first and second aspects, the light emitted from the phase modulation element may be imaged through at least one imaging lens.

By passing through the imaging lens, the light can be easily imaged at the imaging position.

In the vehicle lighting device according to the first and second aspects, the imaging lens may be arranged for each phase modulation element.

In this case, in the first aspect, the convergence angle of the light emitted from each phase modulation element can be adjusted separately, so that the image forming position of light having a shorter wavelength can be easily brought closer to the projection lens.

In addition, in this case, in the second aspect, the convergence angles of the lights emitted from the respective phase modulation elements can be individually adjusted, so that it is easy to form an image of each of the plurality of lights.

In addition, in the vehicle lighting device according to the first and second aspects, the plurality of light sources may include three light sources.

In this case, light of a desired color can be generated.

As described above, according to the first and second aspects of the present invention, a vehicular lamp provided with a projection lens and capable of suppressing color fringing is provided.

1 is a longitudinal sectional view schematically showing a vehicular lamp according to a first embodiment of the present invention. It is an enlarged view of the lamp unit shown in FIG. FIG. 3 is a front view of the phase modulation element shown in FIG. 2. FIG. 4 is a diagram schematically showing a cross section in a thickness direction of a part of the phase modulation element shown in FIG. 3. FIG. 2 is an enlarged view schematically showing the vicinity of an imaging lens and a projection lens in the vehicle lamp shown in FIG. 1. It is a figure which shows the light distribution pattern of a low beam. It is a figure showing a lamp unit of a vehicular lamp concerning a 2nd embodiment of the present invention like FIG. FIG. 8 is a diagram showing the vicinity of a projection lens in the vehicle lamp shown in FIG. 7, similarly to FIG. 5. It is an enlarged drawing which shows roughly the vicinity of the imaging lens and the projection lens in the vehicle lamp concerning 3rd Embodiment of this invention. FIG. 10 is a diagram schematically showing the vicinity of the focal point on the focal plane shown in FIG. 9. It is a figure which shows the vicinity of the projection lens in the vehicle lamp concerning 4th Embodiment of this invention similarly to FIG. It is a figure showing a lamp unit of a vehicular lamp concerning a 5th embodiment of the present invention like FIG. It is a figure which shows the lamp unit of the vehicle lamp concerning 6th Embodiment of this invention similarly to FIG. It is a figure which shows the light distribution pattern of a high beam.

Hereinafter, embodiments for implementing the vehicular lamp according to the present invention will be exemplified with the accompanying drawings. The embodiments illustrated below are for the purpose of facilitating the understanding of the present invention, and are not intended to limit the present invention. The present invention can be modified and improved from the following embodiments without departing from the gist thereof. In the drawings referred to below, the dimensions of each member may be changed in order to facilitate understanding.

First, a first aspect of the present invention will be described using the vehicle headlight according to the first embodiment and the second embodiment as an example.

(1st Embodiment)
Drawing 1 is a figure showing an example of the vehicular lamp concerning this embodiment, and is a longitudinal section showing roughly the section of the vertical direction of the vehicular lamp. In the present embodiment, the vehicular lamp is the vehicular headlamp 1. As shown in FIG. 1, the vehicle headlamp 1 is provided with a housing 10, a lamp unit 20, an imaging lens 81 disposed in front of the lamp unit 20, and disposed in front of the imaging lens 81. Projection lens 80 as a main configuration.

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

The space formed by the lamp housing 11, the front cover 12 closing the front opening of the lamp housing 11, and the back cover 13 closing the rear opening of the lamp housing 11 is a lamp room R. The lamp unit 20, the imaging lens 81, and the projection lens 80 are housed therein.

The lamp unit 20 of the present embodiment includes the heat sink 30, the cooling fan 35, the cover 59, and the optical system unit 50 as main components. The lamp unit 20 is fixed to the housing 10 by a configuration (not shown).

In the present embodiment, the heat sink 30 has a metal base plate 31 extending in a substantially horizontal direction, and a plurality of heat radiation fins 32 are provided integrally with the base plate 31 on the lower surface side of the base plate 31. I have. In addition, the cooling fan 35 is arranged with a gap from the radiation fin 32 and is fixed to the heat sink 30. The heat sink 30 is cooled by the airflow generated by the rotation of the cooling fan 35. A cover 59 is arranged on the upper surface of the base plate 31 of the heat sink 30.

The cover 59 of the present embodiment is made of a metal such as aluminum, for example, and is fixed to the upper surface of the base plate 31 of the heat sink 30. An optical system unit 50 for generating light forming a low beam or the like is accommodated inside the cover 59. An opening 59H is formed at the front of the cover 59, and the light from the optical system unit 50 is emitted forward through the opening 59H.

In order to make the inner walls of the cover 59 have a light absorbing property, it is preferable that these inner walls are subjected to black alumite processing or the like. Since the inner wall of the cover 59 has a light absorbing property, even when the inner wall is irradiated with light due to unintended reflection or refraction, the irradiated light is reflected and emitted from the opening 59H in an unintended direction. Can be suppressed.

The imaging lens 81 is a lens for imaging the light emitted from the opening 59H at a predetermined imaging position. The imaging lens 81 is disposed in front of the opening 59H of the cover 59, and is fixed to the housing 10 by a configuration (not shown). In the example of the present embodiment, the imaging lens 81 is a lens in which the entrance surface and the exit surface are formed in a convex shape, and is formed such that the focal point is located between the imaging lens 81 and the projection lens 80. ing.

The projection lens 80 is a lens for adjusting the divergence angle of the light imaged at the image forming position. That is, when the light passes through the projection lens 80, the divergence angle of the light is adjusted, and the low beam or the like is formed into a predetermined size. The projection lens 80 is arranged in front of the imaging lens 81, and is fixed to the housing 10 by a configuration (not shown). In the example of the present embodiment, the projection lens 80 is a lens in which the entrance surface and the exit surface are formed in a convex shape.

FIG. 2 is an enlarged view of a lamp unit 20 included in the vehicle headlight 1 shown in FIG. As shown in FIG. 2, the optical system unit 50 according to the present 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 54 </ b> B, and a combining optical system 55 as main components. In the present embodiment, the

phase modulation elements

54R, 54G, and 54B are reflection-type phase modulation elements that diffract and emit incident light while reflecting the light, and are, for example, reflection-type LCOS (Liquid Crystal On Silicon). You.

The first light source 52R is a laser element that emits a laser beam having a predetermined wavelength. In the present embodiment, the first light source 52R emits a red laser beam having a power peak wavelength of, for example, 638 nm upward. Each of the second light source 52G and the third light source 52B is a laser element that emits a laser beam having a predetermined wavelength. In the present embodiment, the second light source 52G transmits a green laser beam having a peak wavelength of power of, for example, 515 nm backward. The third light source 52B emits blue laser light having a power peak wavelength of, for example, 445 nm backward. The optical system unit 50 has a circuit board (not shown) fixed to the cover 59. The first light source 52R, the second light source 52G, and the third light source 52B are respectively mounted on the circuit board, and power is supplied to these light sources via the circuit board.

The first collimating lens 53R is disposed above the first light source 52R, and collimates the laser light 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 light emitted from the second light source 52G in the fast axis direction and the slow axis direction. The third collimating lens 53B is disposed behind the third light source 52B, and collimates the laser light emitted from the third light source 52B in the fast axis direction and the slow axis direction. These

collimating lenses

53R, 53G, 53B are fixed to the cover 59 by a configuration not shown.

Note that the collimating lens for collimating the fast axis direction of the laser light and the collimating lens for collimating the slow axis direction may be separately provided, so that the fast axis direction and the slow axis direction of the laser light may be collimated.

The first phase modulation element 54R is disposed above the first collimator lens 53R. Further, the first phase modulating element 54R is arranged at an angle of approximately 45 ° with respect to the front-rear direction and the vertical direction. Accordingly, the red laser light emitted from the first collimating lens 53R is incident on the first phase modulation element 54R, is diffracted, changes its direction by approximately 90 °, and forwards as the red first light DLR, ie, Are emitted toward the combining optical system 55.

The second phase modulation element 54G is disposed behind the second collimating lens 53G. The second phase modulating element 54G is disposed at an angle of approximately 45 ° in the direction opposite to the first phase modulating element 54R with respect to the front-rear direction and the vertical direction. Accordingly, the green laser light emitted from the second collimating lens 53G is incident on the second phase modulation element 54G and is diffracted, changes its direction by approximately 90 °, and moves upward as the green second light DLG, that is, Are emitted toward the combining optical system 55.

The third phase modulation element 54B is disposed behind the third collimating lens 53B. The third phase modulating element 54B is arranged at an angle of approximately 45 ° in the direction opposite to the first phase modulating element 54R with respect to the front-rear direction and the vertical direction. Accordingly, the blue laser light emitted from the third collimating lens 53B is incident on the third phase modulation element 54B and is diffracted, changes its direction by approximately 90 °, and rises upward as blue third light DLB, ie, Are emitted toward the combining optical system 55.

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

The second optical element 55s is disposed in front of the first optical element 55f and above the third phase modulation element 54B, and is inclined by approximately 45 ° in the same direction as the first phase modulation element 54R with respect to the front-rear direction and the vertical direction. It is arranged in a state. The second optical element 55s is a wavelength selection filter, like the first optical element. In the present embodiment, the second optical element 55s transmits red light having a wavelength of 638 nm emitted from the first light source 52R and green light having a wavelength of 515 nm emitted from the second light source 52G, and has a wavelength of 445 nm emitted from the third light source 52B. Is configured to reflect blue light.

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

In the present embodiment, the

phase modulation elements

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

FIG. 3 is a front view of the first phase modulation element 54R. As shown in FIG. 3, the first phase modulation element 54R is formed in a substantially rectangular shape when viewed from the front, and includes a substantially circular incident area 53A into which red laser light emitted from the first collimating lens 53R is incident. . The first phase modulation element 54R has a plurality of modulation units arranged in a matrix in the rectangle. The incident area 53A includes at least one modulation unit. Each modulation unit includes a plurality of dots arranged in a matrix, diffracts while reflecting the incident red laser light, and emits the diffracted light. The drive circuit 60R is electrically connected to the phase modulation element 54R. The driving circuit 60R includes a scanning line driving circuit connected to the side of the phase modulation element 54R and a data line driving circuit connected to one side of the phase modulation element 54R in the vertical direction.

FIG. 4 is a diagram schematically showing a cross section in the thickness direction of a part of the phase modulation element shown in FIG. As shown in FIG. 4, the phase modulation element 54R of the present 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, a transparent electrode 67, and a transparent electrode 67. And an optical substrate 68 as a main configuration.

(4) The plurality of electrodes 64 are arranged on one surface of the silicon substrate 62 in a matrix corresponding to the dots. That is, each dot includes a corresponding electrode 64. The drive circuit layer 63 is a layer in which circuits connected to the scan 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. You. The translucent substrate 68 is arranged on one side of the silicon substrate 62 so as to face the silicon substrate 62, and is, for example, a glass substrate. The transparent electrode 67 is disposed on the surface of the light transmitting substrate 68 on the silicon substrate 62 side. The liquid crystal layer 66 has liquid crystal molecules 66 a and is arranged between the plurality of electrodes 64 and the transparent electrode 67. The reflection film 65 is disposed between the plurality of electrodes 64 and the liquid crystal layer 66, and is, for example, a dielectric multilayer film. The laser light emitted from the collimator lens 53R enters from the surface of the translucent substrate 68 opposite to the silicon substrate 62 side.

As shown in FIG. 4, light RL entering from a surface of the light-transmitting substrate 68 opposite to the silicon substrate 62 side passes through the transparent electrode 67 and the liquid crystal layer 66, is reflected by the reflection film 65, and is reflected by the liquid crystal layer 66. The light passes through the transparent electrode 67 and is emitted from the light-transmitting substrate 68. Here, when a voltage is applied between the 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 electrode 64 and the transparent electrode 67 changes. Due to the change in the light distribution 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 RL transmitted through the liquid crystal layer 66 changes. Therefore, when the light RL passes through the liquid crystal layer 66 and exits from the liquid crystal layer 66, the phase of the light RL exiting from the liquid crystal layer 66 can be changed from the phase of the light RL entering the liquid crystal layer 66. As described above, since the plurality of electrodes 64 are arranged corresponding to each dot of the modulation unit, the voltage applied between the electrode 64 corresponding to each dot and the transparent electrode 67 is controlled. Thus, the orientation of the liquid crystal molecules 66a changes, and the amount of change in the phase of light emitted from each dot can be adjusted according to each dot. By adjusting the refractive index of the liquid crystal layer 66 in each dot in this manner, light emitted from the first phase modulation element 54R can be formed into a predetermined light distribution pattern, and the divergence angle and convergence angle of the light can be adjusted. It can be at a predetermined angle.

In the present embodiment, the first phase modulation element 54R is configured such that the same light distribution pattern is formed in each modulation unit. As described above, since at least one modulation unit is included in the incident area 53A, when the red laser light is incident on the first phase modulation element 54R, a predetermined divergence angle or a predetermined convergence angle is obtained. May be generated. Similarly, the second phase modulation element 54G is configured so that the same light distribution pattern is formed in each modulation unit, and at least one modulation unit is included in the incident area of the second phase modulation element 54G. ing. Therefore, when the green laser light is incident on the second phase modulation element 54G, the second light DLG having a predetermined light distribution pattern having a predetermined divergence angle or a predetermined convergence angle can be generated. Similarly, the third phase modulation element 54B is configured such that the same light distribution pattern is formed in each modulation unit, and at least one modulation unit is included in the incident area of the third phase modulation element 54B. ing. Therefore, when the blue laser light is incident on the third phase modulation element 54B, the third light DLB having a predetermined light distribution pattern having a predetermined divergence angle or a predetermined convergence angle can be generated.

In the example of the present embodiment, the voltages applied to the

phase modulation elements

54R, 54G, and 54B are controlled so that the light distribution patterns of the lights DLR, DLG, and DLB have the same shape, respectively. DLG and DLB are controlled to be emitted from the

phase modulation elements

54R, 54G and 54B at different divergence angles. In the example of the present embodiment, the divergence angle of the light DLR is minimized, and the divergence angle of the light DLB is maximized. In the example of the present embodiment, the divergence of the light DLR, DLG, and DLB is set such that the outer edge of the light DLR is located at the innermost position and the outer edge of the light DLB is located at the outermost position on the emission surface of the second optical element 55s. The corner is adjusted.

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

As shown in FIG. 2, when the first light source 52R is supplied with power from a power supply (not shown), the red laser light is emitted upward. This red laser light is collimated by a first collimating lens 53R disposed above the first light source 52R. When the second light source 52G is supplied with power from a power supply (not shown), the green laser light is emitted backward. This green laser light is collimated by a second collimating lens 53G disposed behind the second light source 52G. When the third light source 52B is supplied with power from a power supply (not shown), the third light source 52B emits blue laser light backward. This blue laser light is collimated by a third collimating lens 53B disposed behind the third light source 52B.

第 A first phase modulating element 54R is disposed above the first collimating lens 53R so as to be inclined at approximately 45 ° with respect to the optical axis of the red laser light emitted from the first light source 52R. Therefore, when this red laser light enters the first phase modulation element 54R, it becomes the first light DLR having a predetermined light distribution pattern, and the first light DLR is emitted forward from the first phase modulation element 54R.

A second phase modulating element 54G is disposed behind the second collimating lens 53G in a state where the second phase modulating element 54G is inclined at approximately 45 ° with respect to the optical axis of the green laser light emitted from the second light source 52G. Therefore, when this green laser light is incident on the second phase modulation element 54G, it becomes a second light DLG having a predetermined light distribution pattern, and this second light DLG is emitted upward from the second phase modulation element 54G.

A third phase modulating element 54B is disposed behind the third collimating lens 53B in a state of being inclined at approximately 45 ° with respect to the optical axis of the blue laser light emitted from the third light source 52B. Therefore, when this blue laser light enters the third phase modulation element 54B, it becomes the third light DLB having a predetermined light distribution pattern, and the third light DLB is emitted upward from the third phase modulation element 54B.

In the example of this embodiment, the shape of the light distribution pattern of the light DLR, DLG, and DLB is similar to the shape of the low beam light distribution pattern and is reduced in a similar manner.

１A first optical element 55f of the combining optical system 55 is disposed 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. In addition, a first optical element 55f is disposed above the second phase modulation element 54G. As described above, the first optical element 55f is configured to reflect green light, and is inclined by approximately 45 ° with respect to the front-back direction and the up-down direction. The second light DLG is reflected by the first optical element 55f and propagates forward. That is, the first combined light LS1 including the first light DLR and the second light DLG propagates toward the second optical element 55s.

２A second optical element 55s of the combining optical system 55 is disposed 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. Further, 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 by approximately 45 ° with respect to the front-rear direction and the up-down direction, so that the second optical element 55s 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 including the first light DLR, the second light DLG, and the third light DLB propagates toward the opening 59H of the cover 59.

In the example of the present embodiment, as described above, the light DLR, DLG, and DLB are arranged such that the outer edge of the light DLR is located on the innermost side and the outer edge of the light DLB is located on the outermost side on the emission surface of the second optical element 55s. Is adjusted. In addition, as described above, the divergence angle of the light DLR is minimized, and the divergence angle of the third light DLB is maximized. Therefore, the second combined light LS2 propagating forward from the second optical element 55s is a combined light in which the outer edge of the first light DLR is located on the innermost side and the outer edge of the third light DLB is located on the outermost side. You. The second combined light LS2 exits from the opening 59H of the cover 59 and enters the imaging lens 81 disposed in front of the cover 59. Therefore, as shown in FIG. 5, on the incident surface of the imaging lens 81, the outer edge of the first light DLR may be located on the innermost side, and the outer edge of the third light DLB may be located on the outermost side. FIG. 5 is an enlarged view schematically showing the vicinity of the imaging lens 81 and the projection lens 80. For easy understanding, light transmitted through the lens is refracted at the center in the width direction of the lens. Is shown in

By the way, the light incident on the lens tends to be refracted more as the wavelength is shorter. Therefore, if the outer edges of the first light DLR, the second light DLG, and the third light DLB overlap each other in the second combined light LS2, the third light DLB having the shortest wavelength is the most light. The first light DLR having the longest wavelength can be refracted the least and form an image at a position farthest from the imaging lens 81 by refracting greatly and forming an image at a position closest to the imaging lens 81.

However, as described above, in the present embodiment, the outer edge of the first light DLR is located on the innermost side, and the outer edge of the third light DLB is located on the outermost side on the incident surface of the imaging lens 81. ing. Therefore, by transmitting the second combined light LS2 through the imaging lens 81, the third light DLB is focused on the imaging position CPB farthest from the imaging lens 81, that is, the imaging light closest to the projection lens 80. An image can be formed at the position CPB. On the other hand, the first light DLR can form an image at an imaging position CPR closest to the imaging lens 81, that is, an imaging position CPR farthest from the projection lens 80. In addition, the second light DLG can form an image at an image forming position CPG between the image forming position CPB and the image forming position CPR.

(4) Lights DLB, DLG, and DLR imaged at the image forming positions CPB, CPG, and CPR enter the projection lens 80 while diverging from the image forming positions CPB, CPG, and CPR, respectively. Therefore, the shape of the light distribution pattern of the light beams DLB, DLG, and DLR incident on the projection lens 80 is inverted from the shape before the image is formed, and the shape of the light distribution pattern of the low beam is reduced to a similar shape. You.

As described above, the third light DLB is imaged at the imaging position CPB closest to the incident surface 80A of the projection lens 80, and the first light DLR is imaged at the imaging position CPB farthest from the incident surface 80A of the projection lens 80. Is imaged. Therefore, in the present embodiment, the incident angle of the third light DLB on the incident surface 80A can be the largest, and the incident angle of the first light DLR on the incident surface 80A can be the smallest. That is, the third light DLB incident on the incident surface 80A at the largest incident angle is refracted most by the projection lens 80, and the first light DLR incident on the incident surface 80A at the smallest incident angle is most reflected by the projection lens 80. Refracts small. As a result, in the second combined light LS2 emitted from the projection lens 80, the respective outer edges of the lights DLR, DLG, and DLB may be nearly parallel.

The low beam L as shown in FIG. 6 can be formed by propagating the second combined light LS2 in which the outer edges of the lights DLR, DLG, and DLB are nearly parallel from the headlight 1 for a vehicle. In FIG. 6, the light distribution pattern is indicated by a thick line, and the straight line S indicates a horizontal line. The area LA1 is the area having the highest light intensity, and the light intensity decreases in the order of the area LA2 and the area LA3.

As described above, according to the vehicle headlamp 1 of the present embodiment, the divergence angle of the light generated by the lamp unit 20 can be adjusted by the projection lens 80 and the light can be emitted, so that the low beam L is formed. That can be easy.

Further, according to the vehicle headlamp 1 of the present embodiment, of the light having a predetermined light distribution pattern formed by the

phase modulation elements

54R, 54G, and 54B, light having a shorter wavelength is formed at a position closer to the projection lens 80. Imaged. As the light having a shorter wavelength is imaged at a position closer to the projection lens 80 as described above, the incident angle of the third light DLB on the incident surface 80A can be maximized, and the incident surface 80A of the first light DLR can be formed. Can be the smallest. As a result, in the second combined light LS2 emitted from the projection lens 80, the outer edges of the lights having different wavelengths become almost parallel to each other, so that the color blur at the outer edge of the combined light emitted from the projection lens 80 can be suppressed. That is, according to the present embodiment, even when the projection lens 80 is used, the low beam L in which color fringing at the outer edge is suppressed can be generated.

In the case where the outer edges of the lights having different wavelengths emitted from the projection lens 80 are parallel to each other, the color bleeding can be effectively suppressed. For example, the imaging position CPR matches the focus of red light on the projection lens 80, the imaging position CPG matches the focus of green light on the projection lens 80, and the imaging position CPB matches the blue light on the projection lens 80. , The outer edges of the light beams DLR, DLG, and DLB emitted from the projection lens 80 are parallel to each other. In addition, when the outer edges of lights having different wavelengths overlap with each other, the color bleeding can be more effectively suppressed.

Further, in the present embodiment, since the shapes of the light distribution patterns of the lights DLR, DLG, and DLB are made identical by the

phase modulation elements

54R, 54G, and 54B, the outer edges of the lights DLR, DLG, and DLB tend to be parallel. Further, the outer edges of the light DLR, DLG, and DLB are likely to overlap each other. Therefore, the color blur can be effectively suppressed.

In this embodiment, since the LCOS is used as the phase modulation element, the light DLR, DLG, and DLB having a desired light distribution pattern can be easily generated by adjusting the voltage applied to the phase modulation element. I can do it. Further, the light imaging position can be appropriately adjusted.

In addition, in the present embodiment, since the first light source 52R, the second light source 52G, and the third light source 52B that emit light of different wavelengths are provided, light of a desired color can be generated.

(2nd Embodiment)
Next, a second embodiment of the present invention will be described. It should be noted that components that are the same as or equivalent to those of the first embodiment are denoted by the same reference numerals unless otherwise specified, and duplicate descriptions are omitted.

FIG. 7 is a diagram showing a lamp unit 20 of the vehicle headlamp 1 according to the second embodiment of the present invention, similarly to FIG. As shown in FIG. 7, the lamp unit 20 in the second embodiment includes a first imaging lens 81R, a second imaging lens 81G, and a third imaging lens near the

phase modulation elements

54R, 54G, and 54B, respectively. This embodiment differs from the lamp unit 20 in the first embodiment in which one imaging lens 81 is disposed outside the lamp unit 20 in that the 81B is disposed. Hereinafter, this point will be described.

As shown in FIG. 7, the lamp unit 20 according to the second embodiment includes a first imaging lens 81R disposed between the first phase modulation element 54R and the first optical element 55f in the front-back direction, and a vertical imaging direction. The second imaging lens 81G disposed between the second phase modulation element 54G and the first optical element 55f, and the second imaging lens 81G disposed between the third phase modulation element 54B and the second optical element 55s in the vertical direction. And three imaging lenses 81B. That is, the lamp unit 20 in the present embodiment has a configuration in which an imaging lens is arranged for each of the

phase modulation elements

54R, 54G, and 54B, that is, in one-to-one correspondence with the

phase modulation elements

54R, 54G, and 54B. .

(4) The

imaging lenses

81R, 81G, and 81B are lenses each having an incident surface and an exit surface formed in a convex shape. Lights DLR, DLG, and DLB emitted from the

phase modulation elements

54R, 54G, and 54B propagate through the

imaging lenses

81R, 81G, and 81B while converging at predetermined convergence angles. In the example of the present embodiment, the convergence angle of the light DLR is maximized, and the convergence angle of the light DLB is minimized. In addition, the convergence angles of the light DLR, DLG, and DLB are adjusted such that the outer edge of the light DLR is located on the innermost side and the outer edge of the light DLB is located on the outermost side on the emission surface of the second optical element 55s.

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

(4) When the red laser light emitted upward from the first collimating lens 53R enters the first phase modulation element 54R, a first light DLR having a predetermined light distribution pattern is generated. The first light DLR is reflected by the first phase modulation element 54R and propagates forward. Further, when the green laser light emitted backward from the second collimating lens 53G enters the second phase modulation element 54G, the second light DLG having a predetermined light distribution pattern is generated. This second light DLG is reflected by the second phase modulation element 54G and propagates upward. Further, when the blue laser light emitted backward from the third collimating lens 53B is incident on the third phase modulation element 54B, the third light DLB having a predetermined light distribution pattern is generated. The third light DLB is reflected by the third phase modulation element 54B and propagates upward. As in the first embodiment, each of the light distribution patterns of these lights DLR, DLG, and DLB has a similar shape that is obtained by inverting the shape of the low beam light distribution pattern and reducing the same. Further, in the present embodiment, the light distribution pattern of the third light DLB on the emission surface of the third phase modulation element 54B, the light distribution pattern of the first light DLR on the emission surface of the first phase modulation element 54R, The light distribution pattern of the second light DLG on the emission surface of the two-phase modulation element 54G has the same size.

The first light DLR is incident on the first imaging lens 81R disposed in front of the first phase modulation element 54R, and is transmitted through the first imaging lens 81R, so that the first light DLR converges at a predetermined convergence angle and moves forward. Propagation to. The second light DLG is incident on the second imaging lens 81G disposed above the second phase modulation element 54G and passes through the second imaging lens 81G, so that the second light DLG converges at a predetermined convergence angle and Propagation to. The third light DLB is incident on the third imaging lens 81B disposed above the third phase modulation element 54B, passes through the third imaging lens 81B, and converges at a predetermined convergent angle. Propagation to.

同様 Similar to the first embodiment, the first light DLR emitted from the first imaging lens 81R passes through the first optical element 55f of the combining optical system 55. Further, the second light DLG emitted from the second imaging lens 81G is reflected forward by the first optical element 55f. Thereby, the first combined light LS1 is generated.

同様 Similar to the first embodiment, the first combined light LS1 emitted from the first optical element 55f passes through the second optical element 55s. Further, the third light DLB emitted from the third imaging lens 81B is reflected forward by the second optical element 55s. Thereby, the second combined light LS2 is generated.

In the example of the present embodiment, the convergence angles of the light DLR, DLG, and DLB are adjusted such that the outer edge of the light DLR is located on the innermost side and the outer edge of the light DLB is located on the outermost side on the exit surface of the second optical element 55s. Is done. Further, the convergence angle of the light DLR is maximized, and the convergence angle of the third light DLB is minimized. Therefore, the second combined light LS2 propagating forward from the second optical element 55s is a combined light in which the outer edge of the first light DLR is located at the innermost position and the outer edge of the third light DLB is located at the outermost position. You. Such a second combined light LS2 is emitted from the opening 59H of the cover 59.

When the second combined light LS2 is emitted to the outside of the cover 59 while being converged from the opening 59H of the cover 59, as shown in FIG. , And the third light DLB whose outer edge is located at the outermost position forms an image at an imaging position CPB closest to the projection lens 80. Therefore, similarly to the first embodiment, the incident angle of the third light DLB on the incident surface 80A can be the largest, and the incident angle of the first light DLR on the incident surface 80A can be the smallest. Therefore, when the second combined light LS2 passes through the projection lens 80, the outer edges of the lights DLR, DLG, and DLB become nearly parallel to each other, and color blur at the outer edge of the combined light LS2 emitted from the projection lens 80 can be suppressed. FIG. 8 is an enlarged view schematically showing the vicinity of the projection lens 80. For easy understanding, light transmitted through the lens is shown to be refracted at the center in the width direction of the lens. .

According to the present embodiment, unlike the first embodiment, the

imaging lenses

81R, 81G, and 81B are provided in one-to-one correspondence with the

light sources

52R, 52G, and 52B. By providing the imaging lenses in a one-to-one correspondence in this manner, the convergence angles of the lights emitted from the respective light sources can be adjusted individually. Therefore, it can be easier to make the image forming position of light having a shorter wavelength closer to the projection lens 80 as compared with the first embodiment.

Next, a second embodiment of the present invention will be described with reference to the vehicle headlights according to the third and fourth embodiments as examples.

(Third embodiment)
First, a third embodiment of the second aspect will be described. It should be noted that components that are the same as or equivalent to those of the first embodiment are denoted by the same reference numerals unless otherwise specified, and duplicate descriptions are omitted.

縦 A vertical cross section of the vehicle headlamp 1 of the present embodiment is represented in the same manner as FIG. The lamp unit 20 of the vehicle headlamp 1 according to the present embodiment is represented in the same manner as in FIG. Further, the

phase modulation elements

54R, 54G, 54B of the present embodiment are represented in the same manner as in FIG. In addition, cross sections in the thickness direction of the

phase modulation elements

54R, 54G, and 54B of the present embodiment are represented in the same manner as in FIG.

Further, in the example of the present embodiment, the projection lens 80 is a lens in which the entrance surface and the exit surface are formed in a convex shape, and is formed so that the focal point is located between the projection lens 80 and the imaging lens 81. Have been. In the present embodiment, the projection lens 80 and the imaging lens 81 are arranged such that the focal point of the projection lens 80 and the focal point of the imaging lens 81 are at the same position.

With such a configuration, similarly to the first embodiment, the light distribution patterns of the light DLR, DLG, and DLB of the present embodiment have the same shape. Further, as shown in FIG. 2, the divergence angles of the light DLR, DLG, and DLB are such that the outer edge of the light DLR is located on the innermost side and the outer edge of the light DLB is located on the outermost side on the exit surface of the second optical element 55s. Is adjusted. Therefore, on the exit surface of the second optical element 55s, the light distribution pattern of the light DLR, the light distribution pattern of the light DLG in which the light distribution pattern of the light DLR is similarly enlarged, and the light DLG are similarly enlarged. The light distribution pattern of the light DLB is superimposed. In the second combined light LS2 in such a state, as described above, the divergence angle of the light DLR is minimized, and the divergence angle of the third light DLB is maximized. Therefore, the second combined light LS2 emitted from the second optical element 55s is a combined light in which the outer edge of the first light DLR is located on the innermost side and the outer edge of the third light DLB is located on the outermost side. The second combined light LS2 exits from the opening 59H of the cover 59 and enters the imaging lens 81 disposed in front of the cover 59.

Therefore, as shown in FIG. 9, on the incident surface of the imaging lens 81, the outer edge of the first light DLR may be located on the innermost side, and the outer edge of the third light DLB may be located on the outermost side. For this reason, the second combined light LS2 emitted from the imaging lens 81 is formed with the outer edge of the first light DLR positioned at the innermost position and the outer edge of the third light DLB positioned at the outermost position. Converge towards the focal point of FIG. 9 is an enlarged view schematically showing the vicinity of the imaging lens 81 and the projection lens 80. For easy understanding, light transmitted through the lens is refracted at the center in the width direction of the lens. Is shown in

As described above and as shown in FIG. 9, the projection lens 80 in the present embodiment is formed so that the focal point F is located between the projection lens 80 and the imaging lens 81. In the example of the present embodiment, as described above, the focal point F of the projection lens 80 and the focal point of the imaging lens 81 are at the same position. A plane passing through the focal point F and perpendicular to the optical axis direction of the projection lens 80 is referred to as a “focal plane SF”.

FIG. 10 is a diagram schematically showing the vicinity of the focal point F on the focal plane SF. The second combined light LS2 converges toward the focal point F in a state where the outer edge of the first light DLR is located at the innermost position and the outer edge of the third light DLB is located at the outermost position. In addition, among the images of the light DLR, DLG, and DLB formed on the focal plane SF, the image of the light DLB having the shortest wavelength is the largest, and the image of the light DLR having the longest wavelength is the smallest. Further, as described above, since the shape of the light distribution pattern of the lights DLR, DLG, and DLB is formed by inverting the shape of the light distribution pattern of the low beam, the lights DLR, DLG, and DLB formed on the focal plane SF. Also has a shape obtained by inverting the shape of the low beam light distribution pattern.

As shown in FIG. 9, after passing through the focal plane SF, the second combined light LS2 has the outer edge of the first light DLR located at the innermost position, and the outer edge of the third light DLB located at the outermost position. The light propagates toward the projection lens 80 while diverging in the state. Therefore, on the incident surface 80A of the projection lens 80, the outer edge of the first light DLR may be located on the innermost side, and the outer edge of the third light DLB may be located on the outermost side. Further, when the second combined light LS2 passes through the focal point F, the shape of the light distribution pattern of the lights DLB, DLG, and DLR is inverted from the shape before passing through the focal point F, and the light distribution pattern of the low beam is incident on the incident surface 80A. Is similarly reduced.

As described above, the light DLB is incident on the outermost surface of the incident surface 80A of the projection lens 80, and the light DLR is incident on the innermost surface of the incident surface 80A. That is, the incident angle of the light DLB on the incident surface 80A can be the largest, and the incident angle of the light DLR on the incident surface 80A can be the smallest. In the lens, the light DLB incident on the projection lens 80 at the largest incident angle can be refracted the most by the projection lens 80, and the light DLB incident on the projection lens 80 can be projected at the smallest incident angle. The light DLR incident on the lens 80 can be refracted the least. Therefore, in the second combined light LS2 emitted from the projection lens 80, the outer edges of the lights DLR, DLG, and DLB may be nearly parallel.

The low beam L as shown in FIG. 6 can be formed by propagating the second combined light LS2 in which the outer edges of the lights DLR, DLG, and DLB are nearly parallel from the headlight 1 for a vehicle.

Further, according to the vehicle headlamp 1 of the present embodiment, among the images of the light DLR, DLG, and DLB formed on the focal plane SF, the image of the light DLR is formed to be the smallest, and the image of the light DLB is formed the most. Due to the large size, the light DLR can be incident on the innermost side of the incident surface 80A of the projection lens 80, and the light DLB having the longest wavelength can be incident on the outermost side of the incident surface 80A. That is, the incident angle of the light DLB having the shortest wavelength on the incident surface 80A can be the largest, and the incident angle of the light DLR having the longest wavelength on the incident surface 80A can be the smallest. For this reason, in the second combined light LS2 emitted from the projection lens 80, the outer edges of the lights DLR, DLG, and DLB are nearly parallel to each other, and color blurring at the outer edge of the combined light emitted from the projection lens 80 can be suppressed. Therefore, according to the present embodiment, even when the projection lens 80 is used, it is possible to generate the low beam L and the like in which color fringing at the outer edge is suppressed. When the outer edges of the lights having different wavelengths are parallel to each other, the color bleeding can be effectively suppressed. In addition, when the outer edges of lights having different wavelengths overlap with each other, the color bleeding can be more effectively suppressed.

In this embodiment, since the LCOS is used as the phase modulation element, the light DLR, DLG, and DLB having a desired light distribution pattern can be easily generated by adjusting the voltage applied to the phase modulation element. I can do it. Further, the size of the light image on the focal plane SF can be appropriately adjusted.

(Fourth embodiment)
Next, a fourth embodiment of the second aspect will be described. It should be noted that components that are the same as or equivalent to those of the first embodiment are denoted by the same reference numerals unless otherwise specified, and duplicate descriptions are omitted.

縦 A longitudinal section of the vehicle headlamp 1 of the present embodiment is represented in the same manner as FIG. In the example of the present embodiment, as shown in FIG. 7, the convergence angle of the light DLR is maximized, and the convergence angle of the light DLB is minimized. In addition, the convergence angles of the light DLR, DLG, and DLB are adjusted such that the outer edge of the light DLR is located on the innermost side and the outer edge of the light DLB is located on the outermost side on the emission surface of the second optical element 55s. In the present embodiment, the convergence angles are adjusted so that the lights DLR, DLG, and DLB converge on the focal point of the projection lens 80, respectively.

Therefore, the second combined light LS2 propagating forward from the second optical element 55s is a combined light in which the outer edge of the first light DLR is located at the innermost position and the outer edge of the third light DLB is located at the outermost position. You. Such second combined light LS2 is emitted from the opening 59H of the cover 59 while converging.

As shown in FIG. 11, in the combined light LS2 emitted from the opening 59H, the outer edge of the first light DLR is located at the innermost position, and the outer edge of the third light DLB is located at the outermost position. Therefore, as in the third embodiment, among the images of the light DLR, DLG, and DLB formed on the focal plane SF, the image of the light DLB having the shortest wavelength can be the largest, and the image of the light DLR having the longest wavelength can be obtained. May be the smallest. Therefore, similarly to the third embodiment, the incident angle of the third light DLB on the incident surface 80A can be the largest, and the incident angle of the first light DLR on the incident surface 80A can be the smallest. Therefore, when the second combined light LS2 passes through the projection lens 80, the outer edges of the lights DLR, DLG, and DLB become nearly parallel, respectively, and color blur at the outer edge of the combined light LS2 emitted from the projection lens 80 can be suppressed.

According to the present embodiment, unlike the third embodiment, the

imaging lenses

81R, 81G, and 81B are provided in one-to-one correspondence with the

light sources

52R, 52G, and 52B. By providing the imaging lenses in a one-to-one correspondence in this manner, the convergence angles of the lights emitted from the respective light sources can be adjusted individually. Therefore, of the light images formed on the focal plane SF, it can be easier to increase the size of the light image having a shorter wavelength as compared with the third embodiment.

(Fifth embodiment)
Next, a fifth embodiment of the present invention will be described. It should be noted that components that are the same as or equivalent to those of the first embodiment are denoted by the same reference numerals unless otherwise specified, and duplicate descriptions are omitted.

FIG. 12 is a view showing a lamp unit 20 of the vehicle headlamp 1 according to the fifth embodiment of the present invention, similarly to FIG. As shown in FIG. 12, the lamp unit 20 according to the fifth embodiment is different from the lamp unit 20 according to the first embodiment in that the phase modulation element is configured by a transmission-type phase modulation element. Hereinafter, this point will be described.

As shown in FIG. 12, the lamp unit 20 according to the present embodiment includes a first light source 52R, a second light source 52G, and a third light source 52B that are arranged in the vertical direction, and the

light sources

52R, 52G, and 52B. A first collimating lens 53R, a second collimating lens 53G, and a third collimating lens 53B respectively correspondingly disposed on the front side, and a first phase modulation disposed respectively forwardly corresponding to the

collimating lenses

53R, 53G, 53B. An element 54R, a second phase modulation element 54G, a third phase modulation element 54B, a combining optical system 55, a first reflection mirror 58G, and a second reflection mirror 58B are provided as main components. In the present embodiment, the inclination directions of the first optical element 55f and the second optical element 55s of the combining optical system 55 are opposite to each other. In the present embodiment, the first light source 52R is disposed near the center in the vertical direction, the second light source 52G is disposed above the first light source 52R, and the third light source 52B is disposed below the first light source 52R. You.

The first reflection mirror 58G is disposed in front of the second phase modulation element 54G and above the first optical element 55f in a state in which the first reflection mirror 58G is inclined by approximately 45 ° in the same direction as the first optical element 55f with respect to the front-rear direction and the vertical direction. Is done. The second reflection mirror 58B is disposed in front of the first optical element 55f and above the third phase modulation element 54B in a state where the second reflection mirror 58B is inclined at approximately 45 ° in the same direction as the second optical element 55s with respect to the front-rear direction and the vertical direction. Is done.

In the present embodiment, the

phase modulation elements

54R, 54G, 54B are transmission LCOSs, unlike the

phase modulation elements

54R, 54G, 54B in the first embodiment. These

phase modulation elements

54R, 54G, 54B are arranged at predetermined intervals in the vertical direction corresponding to the three

light sources

52R, 52G, 52B.

That is, when the red laser light emitted from the first collimating lens 53R passes through the first phase modulation element 54R, the phase of the red laser light changes, and the first light DLR having a predetermined light distribution pattern is generated. Is done. Further, the green laser light emitted from the second collimating lens 53G passes through the second phase modulation element 54G, so that the phase of the green laser light changes, and the second light DLG having a predetermined light distribution pattern is generated. Is done. Further, the blue laser light emitted from the third collimating lens 53B passes through the third phase modulation element 54B, so that the phase of the blue laser light changes, and the third light DLB having a predetermined light distribution pattern is generated. Is done.

In the example of the present embodiment, as in the first embodiment, the divergence angles of the light DLR, DLG, and DLB are increased in the order of the light DLR, the light DLG, and the light DLB. The divergence angles of the lights DLR, DLG, and DLB are angles at which the outer edge of the light DLR is located at the innermost position and the outer edge of the light DLB is located at the outermost position on the emission surface of the second optical element 55s.

Next, light emission from the lamp unit 20 of the present embodiment will be described.

When red laser light is emitted from the first light source 52R, the red laser light is collimated by the first collimating lens 53R and then enters the incident area of the first phase modulation element 54R. This red laser light is transmitted through the phase modulation element 54R to generate a first light DLR having a predetermined light distribution pattern. The first light DLR is emitted forward from the first phase modulation element 54R at the smallest divergence angle.

(4) When green laser light is emitted from the second light source 52G, this green laser light is collimated by the second collimating lens 53G and then enters the incident area of the phase modulation element 54G. This green laser light is transmitted through the phase modulation element 54G, and a second light DLG having a predetermined light distribution pattern is generated. The second light DLG is emitted forward from the second phase modulation element 54G at a larger divergence angle than the first light DLR.

(4) When blue laser light is emitted from the third light source 52B, this blue laser light is collimated by the third collimating lens 53B and then enters the incident area of the phase modulation element 54B. The blue laser light passes through the phase modulation element 54B, and generates a third light DLB having a predetermined light distribution pattern. The third light DLB is emitted forward from the third phase modulation element 54B at a larger divergence angle than the second light DLG.

には A first reflection mirror 58G is disposed at an angle of approximately 45 ° in the front-rear direction and the vertical direction in front of the emission direction of the second light DLG. For this reason, the second light DLG is reflected by the first reflection mirror 58G and exits downward from the first reflection mirror 58G.

１A first optical element 55f of the combining optical system 55 is disposed in front of the emission direction of the first light DLR. Therefore, like the first embodiment, the first light DLR transmits through the first optical element 55f and propagates forward. The first optical element 55f is disposed below the first reflecting mirror 58G in a state where the first optical element 55f is inclined in the same direction as the first reflecting mirror 58G. Therefore, the second light DLG emitted from the first reflection mirror 58G is reflected by the first optical element 55f and propagates forward. Thereby, the first combined light LS1 is generated, and the first combined light LS1 propagates toward the second optical element 55s of the combined optical system 55. In the example of the present embodiment, as described above, the divergence angle of the second light DLG is set to be larger than the divergence angle of the first light DLR, so that the first combined light LS1 has the divergence angle of the second light DLG. The outer edge is located slightly outside the outer edge of the first light DLR.

前方 A second reflection mirror 58B is disposed at an angle of approximately 45 ° in the front-rear direction and the vertical direction in front of the emission direction of the third light DLB. The inclination direction of the second reflection mirror 58B is opposite to the inclination direction of the first reflection mirror 58G. Therefore, the third light DLB is reflected by the second reflection mirror 58B and is emitted upward from the second reflection mirror 58B.

には A second optical element 55s of the combining optical system 55 is disposed in front of the emission direction of the first combined light LS1. Therefore, like the first embodiment, the first combined light LS1 passes through the second optical element 55s and propagates forward. The second optical element 55s is disposed above the second reflection mirror 58B in a state where the second optical element 55s is inclined in the same direction as the second reflection mirror 58B. Therefore, the third light DLB emitted from the second reflection mirror 58B is reflected by the second optical element 55s and propagates forward. Thereby, the second combined light LS2 is generated. The second combined light LS2 propagates through the opening 59H of the cover 59 toward the imaging lens 81 as in the first embodiment. In the example of the present embodiment, as described above, the divergence angle of the third light DLB is set to be larger than the divergence angle of the second light DLG. The outer edge is located on the outermost side, and the outer edge of the first light DLR is located on the innermost side.

In the first embodiment, as shown in FIG. 5, as a result of forming such a second combined light LS <b> 2 by the imaging lens 81, the first light DLR is focused on the imaging position closest to the projection lens 80. An image is formed on the CPB, and the third light is formed on the image forming position CPR farthest from the projection lens 80. Therefore, similarly to the first embodiment, in the second combined light LS2 emitted from the projection lens 80, the outer edges of the lights DLR, DLG, and DLB can be nearly parallel. Therefore, color bleeding at the outer edge of light can be suppressed.

In the second embodiment, as shown in FIG. 9, the second combined light LS2 is converged by the imaging lens 81 as shown in FIG. 9, and as a result, as shown in FIG. May be the smallest, and the image of the third light DLB may be the largest. Therefore, similarly to the third embodiment, in the second combined light LS2 emitted from the projection lens 80, the outer edges of the lights DLR, DLG, and DLB may be nearly parallel. Therefore, color bleeding at the outer edge of light can be suppressed.

As described above, according to the fifth embodiment of the present invention, the same effects as those of the first and third embodiments can be realized using the transmission type phase modulation element.

(Sixth embodiment)
Next, a sixth embodiment of the present invention will be described. It should be noted that components that are the same as or equivalent to those of the first embodiment are denoted by the same reference numerals unless otherwise specified, and duplicate descriptions are omitted.

FIG. 13 is a view showing a lamp unit 20 of the vehicle headlamp 1 according to the fourth embodiment of the present invention, similarly to FIG. In FIG. 13, the heat sink 30, the cover 59, and the like of the lamp unit 20 are omitted for easy understanding. As shown in FIG. 13, the lamp unit 20 according to the fourth embodiment is different from the optical system unit 50 in that the number of phase modulation elements is one, and three phase modulation elements are provided for each light source. This is different from the lamp unit 20 in the first to third embodiments in which the optical system unit 50 is constituted by 54R, 54G, 54B. Hereinafter, the configuration of the lamp unit 20 according to the fourth embodiment will be described.

In the present 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. These three

light sources

52R, 52G, 52B are connected to a control unit (not shown). This control unit does not emit light from the

light sources

52G and 52B while the light source 52R emits red laser light, and emits light from the

light sources

52R and 52B while the light source 52G emits green laser light. Are not emitted, and the operation of the

light sources

52R, 52G, 52B is controlled such that the light from the

light sources

52R, 52G is not emitted while the light source 52B emits the blue laser light. That is, the

light sources

52R, 52G, and 52B in the present embodiment switch the light emission from each light source at a predetermined cycle based on the control of the control unit.

As in the other embodiments, the laser beams emitted from the

light sources

52R, 52G, 52B are collimated by the

collimating lenses

53R, 53G, 53B.

合成 A combining optical system 55 is provided above the collimating lens 53R and behind the

collimating lenses

53G and 53B. That is, the first optical element 55f is provided above the collimator lens 53R and behind the collimator lens 53G, and the second optical element 55s is provided above the first optical element 55f and behind the collimator lens 53B. These

optical elements

55f and 55s are arranged at an angle of approximately 45 ° in the front-rear direction and the vertical direction.

位相 One phase modulation element 54S is provided above the second optical element 55s. The phase modulation element 54S is disposed at a position where the red laser light, the green laser light, and the blue laser light that have passed through the combining optical system 55 can enter. In the present embodiment, the phase modulation element 54S is arranged such that the red laser light, the green laser light, and the blue laser light are incident on the same region on the incident surface of the phase modulation element 54S. Note that the red laser light, the green laser light, and the blue laser light do not necessarily need to be incident on the same area on the incident surface. The phase modulation element 54S in the present embodiment is, for example, a reflection type LCOS. The phase modulation element 54S is arranged to be inclined at approximately 45 ° in the front-rear direction and the vertical direction, and the inclination direction is opposite to the

optical elements

55f and 55s.

In addition, in the present embodiment, the voltage applied to the phase modulation element 54S is adjusted so that the diffraction pattern of the phase modulation element 54S changes according to the wavelength of the incident light. Specifically, the voltage is controlled so that the light distribution patterns of the red laser light, the green laser light, and the blue laser light emitted from the phase modulation element 54S have the same shape. The convergence angle of the red laser light is controlled to be the largest, and the convergence angle of the blue laser light emitted from the phase modulation element 54S is minimized.

As described above, the

light sources

52R, 52G, and 52B in the present embodiment switch the emission of light from each light source at a predetermined cycle based on the control of the control unit. For example, first, a red laser beam is emitted from the first light source 52R for a predetermined time. During this time, the laser beams from the

light sources

52G and 52B are not emitted. After being collimated by the collimator lens 53R, the red laser light passes through the combining optical system 55 and enters the phase modulation element 54S. Note that, as described above, the red laser light, the green laser light, and the blue laser light in the present embodiment are incident on the same region on the incident surface of the phase modulation element 54S.

(4) When red laser light is incident on the phase modulation element 54S, the voltage applied to the phase modulation element 54S is adjusted so that a diffraction pattern corresponding to the red laser light is obtained. That is, as described above, the diffraction pattern of the phase modulation element 54S changes so that the light distribution pattern has a predetermined shape and the convergence angle of the red laser light is maximized. The red laser light diffracted by this diffraction pattern becomes the first light DLR and propagates forward.

(4) After a lapse of a predetermined time, the light from the light source 52R is in a non-emission state, and instead of the light from the light source 52R, the green laser light is emitted from the light source 52G for a predetermined time. The green laser light is collimated by the collimator lens 53G, passes through the combining optical system 55, and enters the phase modulation element 54S.

(4) When green laser light is incident on the phase modulation element 54S, the voltage applied to the phase modulation element 54S is adjusted so that a diffraction pattern corresponding to the green laser light is obtained. That is, as described above, the phase modulation element is formed so that the light distribution pattern has the same shape as the first light DLR, and the convergence angle of the green laser light is smaller than that of the red laser light. The 54S diffraction pattern changes. The green laser light diffracted by this diffraction pattern becomes the second light DLG and propagates forward.

(4) After a further predetermined time, the light from the light source 52G is in a non-emission state, and instead of the light from the light source 52G, the blue laser light is emitted from the light source 52B for a predetermined time. After being collimated by the collimator lens 53B, this blue laser light passes through the combining optical system 55 and enters the phase modulation element 54S.

(4) When blue laser light enters the phase modulation element 54S, the voltage applied to the phase modulation element 54S is adjusted so that a diffraction pattern corresponding to the blue laser light is obtained. That is, as described above, the diffraction pattern of the phase modulation element 54S is changed so that the light distribution pattern has the same shape as the light DLR and DLG and the convergence angle of the blue laser light is the smallest convergence angle. Change. The blue laser light diffracted by this diffraction pattern becomes the third light DLB and propagates forward.

The light emission cycle as described above is repeated at a predetermined cycle.

As described above, the convergence angle of the first light DLR emitted from the phase modulation element 54S is maximized, and the convergence angle of the third light DLB emitted from the phase modulation element 54S is minimized. Outer edges of the light DLR, DLG, and DLB emitted from the modulation element 54S, the outer edge of the light DLR is located at the innermost position, and the outer edge of the light DLB is located at the outermost position. In the first embodiment, when such lights DLR, DLG, and DLB exit the cover 59 while converging from the openings 59H of the cover 59, the outer edge is located at the innermost side as shown in FIG. The first light DLR forms an image at an imaging position CPR farthest from the projection lens 80, and the third light DLB having the outer edge positioned at the outermost forms an image at an imaging position CPB closest to the projection lens 80. Therefore, similarly to the first embodiment, the incident angle of the third light DLB on the incident surface 80A can be the largest, and the incident angle of the first light DLR on the incident surface 80A can be the smallest. Therefore, the light DLR, DLG, and DLB each pass through the projection lens 80, so that the outer edges of the light DLR, DLG, and DLB can be nearly parallel.

As described above, the convergence angle of the first light DLR emitted from the phase modulation element 54S is maximized, and the convergence angle of the third light DLB emitted from the phase modulation element 54S is minimized. Outer edges of the light DLR, DLG, and DLB emitted from the modulation element 54S, the outer edge of the light DLR is located at the innermost position, and the outer edge of the light DLB is located at the outermost position. In the second aspect, as described above, since the

light sources

52R, 52G, and 52B switch the light emission at a predetermined cycle, the lights DLR, DLG, and DLB are alternately emitted to the outside of the optical system unit 50. , An image is formed alternately at the focal point F. As described above, the shapes of the light distribution patterns of the light DLR, DLG, and DLB are the same, and the outer edge of the light DLR is located at the innermost position, and the outer edge of the light DLB is located at the outermost position. The formed images of the light DLR, DLG, and DLB are superimposed such that the outer edge of the image of the light DLR is the innermost and the outer edge of the image of the light DLR is the outermost (see FIG. 10).

Therefore, similarly to the third to fifth embodiments, the incident angle of the third light DLB on the incident surface 80A of the projection lens 80 can be the largest, and the incident angle of the first light DLR on the incident surface 80A. May be the smallest. Therefore, when the lights DLR, DLG, and DLB pass through the projection lens 80, the outer edges of the lights DLR, DLG, and DLB can be nearly parallel (see FIG. 9).

Further, as described above, since the

light sources

52R, 52G, and 52B in the present embodiment switch the light emission at a predetermined cycle, the light DLR, DLG, and light DLB are alternately emitted from the projection lens 80 at a predetermined cycle. You. If this period is shorter than the temporal resolution of human vision, an afterimage effect occurs, and the human can perceive that light of different colors is synthesized and emitted. Therefore, by making the period shorter than the time resolution of a person in the present embodiment, the person can obtain white light obtained by combining the light DLR that is red light, the light DLG that is green light, and the DLB that is blue light. It can be recognized that the light is emitted from the lamp unit 20. As described above, since the outer edges of the lights DLR, DLG, and DLB constituting the white light are close to being parallel to each other, a person recognizes that the white light in which the color fringing of the outer edge is suppressed is irradiated. obtain.

Since the time resolution of human vision is approximately 1/30 s, the above cycle is preferably set to 1/30 s or less, more preferably 1/60 s or less. Note that the afterimage effect can occur even when the period is longer than 1/30 s. For example, even if the period is 1/15 s, the afterimage effect may occur.

According to this embodiment, unlike the first to fifth embodiments, the number of phase modulation elements can be reduced to one, so that the number of components can be reduced and the cost can be reduced.

In the present embodiment, an example has been described in which the

light sources

52R, 52G, and 52B switch light emission. However, at least two of the

light sources

52R, 52G, and 52B may switch light emission at a predetermined cycle. For example, the fourth embodiment may be modified so that the

light sources

52R and 52G switch light emission at a predetermined cycle. In this modification, the optical system is composed of two phase modulation elements, a phase modulation element that receives red laser light and green laser light from the

light sources

52R and 52G, and a phase modulation element 54B that receives blue laser light from the light source 52B. Unit 50 may be configured.

Also, in the present embodiment, an example in which light is converged by the phase modulation element has been described, but light may be diverged by the phase modulation element. In this case, a converging lens may be provided between the phase modulation element and the projection lens as in the first and third embodiments.

Also, in the present embodiment, an example in which the phase modulation element is of a reflection type has been described. However, as in the fifth embodiment, the phase modulation element may be of a transmission type.

The first, second, third, fourth, fifth, and sixth embodiments have been described as examples of the present invention, but the present invention is not limited to these embodiments. Not something.

For example, in the first, second, third, and fourth embodiments, examples in which LCOS is used as the phase modulation element have been described, but a diffraction grating may be used as the phase modulation element. However, if the phase modulation element is LCOS, a desired light distribution pattern can be obtained by adjusting the applied voltage, so that a desired light distribution pattern can be formed as compared with a case where a diffraction grating is used as the phase modulation element. Can be easier. Further, GLV (Grating @ Light @ Valve) may be used as the phase modulation element. This GLV is a reflection-type phase modulation element in which a plurality of reflectors are provided on a silicon substrate. According to the GLV, different diffraction patterns can be formed by electrically controlling the deflection of the plurality of reflectors. Therefore, for example, the phase modulation element of the fourth embodiment may be a GLV instead of the LCOS.

In the first embodiment, the second embodiment, the third embodiment, the fourth embodiment, the fifth embodiment, and the sixth embodiment, the vehicle headlamp 1 as a vehicle lamp emits a low beam L. However, the present invention is not particularly limited. For example, the vehicular lamp according to another embodiment is configured to irradiate a region indicated by a broken line in FIG. 6, that is, a region above a region irradiated with the low beam L with light having a lower intensity than the low beam L. May be done. Such low-intensity light is, for example, light OHS for sign recognition. In this case, it is preferable that the light emitted from each of the

phase modulation elements

54R, 54G, and 54B contains light OHS for label recognition. Further, in such an embodiment, it can be understood that the light distribution pattern for night illumination is formed by the low beam L and the light OHS for sign recognition. It should be noted that the “nighttime” here is not limited to simply “nighttime” but includes a dark place such as a tunnel. Further, a vehicle lamp according to another embodiment may be configured to emit a high beam H as shown in FIG. In FIG. 14, the light distribution pattern of the high beam H is indicated by a bold line, and the straight line S is a horizontal line. In the light distribution pattern of the high beam H, the area HA1 is an area where the light intensity is high, and the area HA2 is an area where the light intensity is lower than that of the HA1. In still another embodiment, the vehicular lamp according to the present invention may be applied as 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.

In the first embodiment, the second embodiment, the third embodiment, the fourth embodiment, the fifth embodiment, and the sixth embodiment, examples in which three

light sources

52R, 52G, and 52B are provided have been described. It is sufficient that at least one light source emits light of different wavelengths, that is, at least two light sources. However, as in the first embodiment, the second embodiment, the third embodiment, and the fourth embodiment, one light source that emits light of different wavelengths is provided, that is, three light sources are provided. It may be possible to generate light of any color.

In the first embodiment, the second embodiment, the third embodiment, the fourth embodiment, the fifth embodiment, and the sixth embodiment, the projection lens 80 in which the entrance surface and the exit surface are formed in a convex shape is used. Although the example of use has been described, the present invention is not limited to this, and a lens having an incident surface formed in a planar shape and an exit surface formed in a convex shape may be used as the projection lens.

In the first aspect, if the shorter the wavelength of the plurality of lights in the predetermined light distribution pattern by the phase modulation element, the closer the image is formed to the projection lens, the divergence angle of the plurality of lights and the The convergence angle can be appropriately changed. For example, a divergence angle and a convergence angle of a plurality of lights may be the same.

In the second aspect, the divergence angle and the convergence angle of the plurality of lights are appropriately changed as long as the shorter the wavelength of the light image among the plurality of light images formed on the focal plane, the larger the image. be able to. For example, a divergence angle and a convergence angle of a plurality of lights may be the same.

According to the present invention, a vehicle lamp provided with a projection lens and capable of suppressing color fringing is provided, and can be used in the field of vehicle lamps such as automobiles.

1 ... Vehicle headlight (vehicle lamp)
20, lamp unit 50, optical system unit 52R, first light source 52G, second light source 52B, third light source 54R, first phase modulation element 54G, second phase Modulating element 54B Third phase modulating element 54S Phase modulating element 55 Synthetic optical system 80 Projection lens 81 Imaging lens 81R First imaging lens 81G .2nd imaging lens 81B... 3rd imaging lens

Claims

A plurality of light sources that emit light having different wavelengths from each other;
By diffracting the light emitted from each of the plurality of light sources, at least one phase modulation element that sets each of the plurality of lights to a predetermined light distribution pattern,
A projection lens for adjusting a divergence angle of the plurality of lights emitted from the phase modulation element,
With
A plurality of the light beams having the predetermined light distribution pattern formed by the phase modulation element form an image at a position closer to the projection lens as light having a shorter wavelength.
The vehicular lamp according to claim 1, wherein outer edges of the plurality of lights emitted from the projection lens are parallel to each other.
The vehicular lamp according to claim 2, wherein each of the plurality of lights forms an image at a focal point of the projection lens.
The vehicular lamp according to claim 2, wherein outer edges of the plurality of lights emitted from the projection lens overlap with each other.
5. The vehicular lamp according to claim 1, wherein the predetermined light distribution patterns of the plurality of lights have the same outer shape. 6.
A plurality of light sources that emit light having different wavelengths from each other;
By diffracting the light emitted from each of the plurality of light sources, at least one phase modulation element that makes the plurality of lights have the same shape light distribution pattern,
A projection lens for adjusting a divergence angle of the plurality of lights emitted from the phase modulation element,
With
A vehicular lamp characterized in that, among a plurality of light images formed on a focal plane that passes through the focal point of the projection lens and is perpendicular to the optical axis direction of the projection lens, an image of light with a shorter wavelength is enlarged. .
The vehicular lamp according to claim 6, wherein outer edges of the plurality of lights emitted from the projection lens are parallel to each other.
The vehicular lamp according to claim 7, wherein outer edges of the plurality of lights emitted from the projection lens overlap each other.
The vehicular lamp according to any one of claims 1 to 8, wherein the phase modulation element is provided for each of the plurality of light sources.
At least two light sources among the plurality of light sources switch the emission of the light from each light source at a predetermined cycle,
The plurality of lights emitted from the at least two light sources are incident on a common phase modulation element,
9. The device according to claim 1, wherein the phase modulation element on which the light from the at least two light sources is incident changes a diffraction pattern according to a wavelength of the incident light. Vehicle lighting.
The vehicular lamp according to claim 10, wherein the cycle is 1 / 30s or less.
The vehicular lamp according to any one of claims 1 to 11, wherein the phase modulation element is a liquid crystal on silicon (LCOS).
The vehicular lamp according to any one of claims 1 to 12, wherein the light emitted from the phase modulation element is imaged through at least one imaging lens.
14. The vehicular lamp according to claim 13, wherein the imaging lens is arranged for each phase modulation element.
The vehicular lamp according to any one of claims 1 to 14, wherein the plurality of light sources includes three light sources.