WO2019230664A1 - Lamp for vehicles - Google Patents

Abstract

According to the present invention, a headlight (1) for vehicles is provided with: a phase modulation element (22) which can modulate a light distribution pattern of output light while diffracting input light and outputting the diffracted light; and a light source (21) which outputs laser beams (LR, LG, LB) having different wavelengths in a time-division manner. The laser beams (LR, LG, LB), which have the different wavelengths and are output from the light source (21), are input to the phase modulation element (22). The phase modulation element (22) diffracts the laser beams (LR, LG, LB) in phase modulation patterns corresponding to the laser beams (LR, LG, LB) having the different wavelengths and then outputs the diffracted laser beams. Areas, onto which light (DLR, DLG, DLB) output from the phase modulation element (22) and corresponding to the respective laser beams (LR, LG, LB) having the different wavelengths are irradiated, are superimposed on each other.

Description

Vehicle lighting

The present invention relates to a vehicular lamp.

As vehicle lamps, vehicle headlamps typified by automobile headlights, drawing devices that draw images on road surfaces, and the like are known. By the way, various configurations have been studied in order to make the light distribution pattern in the vehicular lamp a predetermined light distribution pattern. For example, Patent Document 1 listed below uses a hologram element which is a kind of diffraction grating to determine a predetermined light distribution pattern. The formation of a light distribution pattern is described.

The vehicle headlamp includes a hologram element and a light source for irradiating the hologram element with reference light. The hologram element is calculated so that the diffracted light reproduced by irradiating the reference light forms a low beam light distribution pattern. The vehicle headlamp forms a low beam light distribution pattern by the hologram element as described above, and therefore does not require a shade and can be miniaturized.

JP 2012-146621 A

The vehicular lamp according to the first aspect of the present invention includes a phase modulation element capable of diffracting and emitting incident light and changing a light distribution pattern of the emitted light, and time-dividing a plurality of laser beams having different wavelengths. The laser light of each wavelength emitted from the light source is incident on the phase modulation element, and the phase modulation element is a phase modulation pattern corresponding to the laser light of each wavelength The laser light is diffracted and emitted, and regions irradiated with light emitted from the phase modulation element corresponding to the laser light having the respective wavelengths are overlapped with each other.

In such a vehicular lamp, a plurality of laser beams having different wavelengths emitted from a light source in a time division manner are diffracted by the phase modulation element and emitted from the phase modulation element. In addition, regions irradiated with light emitted from the phase modulation elements corresponding to the laser beams having the respective wavelengths overlap each other. For this reason, light with different wavelengths is sequentially irradiated to the region irradiated with light. By the way, when light with different wavelengths, that is, light with different colors is repeatedly irradiated with a period shorter than the temporal resolution of human vision, a person is irradiated with light that is synthesized with light of these different colors by an afterimage phenomenon. Can be recognized. Therefore, when a plurality of laser beams having different wavelengths are repeatedly emitted from the light source at a cycle shorter than the temporal resolution of human vision, the vehicular lamp is a light in which the plurality of laser beams emitted from the light source are combined. Can be irradiated by an afterimage phenomenon.

Further, in the above vehicle lamp, the phase modulation element diffracts and emits the laser beam with a phase modulation pattern corresponding to the laser beam of each wavelength. Therefore, the phase modulation element corresponds to the laser beam of each wavelength. The light distribution pattern of the light emitted from each can be changed to a desired light distribution pattern. Therefore, the vehicular lamp can suppress the outer shape of the region irradiated with the light emitted from the phase modulation element corresponding to the laser light of each wavelength from being shifted, and the edge of the light distribution pattern formed by the afterimage phenomenon. It is possible to suppress the occurrence of color bleeding in the vicinity.

It is preferable that at least a part of the outer shape of the region irradiated with the light emitted from the phase modulation element corresponding to the laser light of each wavelength matches.

By adopting such a configuration, it is possible to further suppress the occurrence of color bleeding near the edge of the light distribution pattern formed by the afterimage phenomenon.

The phase modulation element may be a transmission type phase modulation element, and the phase modulation element may be a reflection type phase modulation element.

It is preferable that the light source emits at least three laser beams having different wavelengths.

In this case, laser beams of three primary colors can be used. Therefore, by adjusting the intensity of each laser beam emitted from the light source, light of a desired color can be irradiated by the afterimage phenomenon.

The vehicular lamp according to the second aspect of the present invention diffracts light emitted from the light source with a light source that emits light of a predetermined wavelength and a phase modulation pattern that changes at a time interval shorter than the predetermined time interval. And a phase modulation element that emits light, and regions irradiated with light emitted from the phase modulation elements having different phase modulation patterns are overlapped with each other.

In such a vehicular lamp, as described above, the phase modulation element diffracts and emits light emitted from the light source with a phase modulation pattern that changes at a time interval shorter than a predetermined time interval. For this reason, at least one of the light distribution pattern of the light emitted from the phase modulation element and the region irradiated with the light can change corresponding to the change of the phase modulation pattern. Further, as described above, regions irradiated with light emitted from phase modulation elements having different phase modulation patterns overlap each other. For this reason, visually overlapped light occurs in the part of the irradiated object where these regions overlap each other, and the optical path from the phase modulation element to this part changes the phase modulation pattern. It changes corresponding to. When the optical path changes in this way, even at the same position of the irradiated object, the incident angle and the phase of the light incident on the irradiated object from the vehicular lamp can be changed. Accordingly, it is possible to suppress the visual superimposition of light having different angles of incidence and phases and to prevent the light from flickering. The phase modulation pattern indicates a pattern for modulating the phase of light incident on the phase modulation element.

Further, in the vehicular lamp of the second aspect, the region irradiated with the light emitted from the phase modulation element may vibrate in a predetermined direction corresponding to the change of the phase modulation pattern.

In the vehicular lamp of the second aspect, the intensity distribution in the light distribution pattern of the light emitted from the phase modulation element may change corresponding to the change in the phase modulation pattern. Note that the intensity distribution and the outer shape of the light distribution pattern of the light emitted from the phase modulation element may change corresponding to the change of the phase modulation pattern, or only the intensity distribution may change. Further, only the intensity distribution may be changed without changing the region irradiated with the light emitted from the phase modulation element, corresponding to the change of the phase modulation pattern.

In the vehicular lamp according to the second aspect, it is preferable that the predetermined time interval is 1/15 s or less.

With such a configuration, the time interval of visual light superposition is 1/15 s or less. The human visual temporal resolution is approximately 1/30 s. In the case of a vehicular lamp, it is possible to suppress the flickering of light if the visual light overlapping time interval is about twice this time.

In the vehicle lamp of the second aspect, the phase modulation element may be a transmission type phase modulation element, and the phase modulation element is a reflection type phase modulation element. May be.

The vehicular lamp according to the third aspect of the present invention includes a light source that emits light having a predetermined wavelength and an arrangement that generates light having a predetermined light distribution pattern by changing a traveling direction of at least a part of the light. An optical pattern forming element and a movable reflecting member having a movable reflecting surface and moving the movable reflecting surface to vibrate the optical path of the light are provided.

Since the vehicular lamp according to the third aspect includes a light distribution pattern forming element formed of, for example, a diffraction grating, a predetermined light distribution can be achieved without using a shade, similar to the vehicular headlamp described in Patent Document 1. Pattern light can be emitted. Therefore, it can be reduced in size as compared with the vehicular lamp using the shade as in the vehicular headlamp disclosed in Patent Document 1.

The vehicle lamp according to the third aspect includes a movable reflecting member that moves the movable reflecting surface to vibrate the optical path of light having a predetermined light distribution pattern. According to such a configuration, the incident angle and phase of light having a predetermined light distribution pattern incident on the irradiated object can be changed with time in accordance with the vibration of the optical path. The change in the incident angle of the light and the phase of the light continuously occur to generate various interference patterns, and the respective lights of these interference patterns are superimposed. As a result, speckle becomes inconspicuous and light flicker can be suppressed.

In the vehicle lamp of the third aspect, it is preferable that the movable reflecting surface of the movable reflecting member reflects the light emitted from the light source toward the light distribution pattern forming element.

In this case, since the movable reflecting member can be arranged closer to the light source than the light distribution pattern forming element, the movable reflecting surface can be made small.

In the vehicle lamp of the third aspect, the movable reflecting surface of the movable reflecting member may reflect the light emitted from the light distribution pattern forming element.

In the vehicle lamp of the third aspect, the reflecting member may be a MEMS mirror or a polygon mirror, for example.

In the vehicular lamp of the third aspect, it is preferable that the movable reflecting member vibrates the optical path of the light in two or more directions.

In this case, as compared with the case where the optical path of light vibrates only in one direction, visually overlapping light is generated in multiple directions, and the flickering of light can be further suppressed.

In the vehicular lamp of the third aspect, it is preferable that the movable reflecting member vibrate the optical path of the light at a frequency of 15 Hz or more.

The human visual temporal resolution is approximately 30 Hz. In the case of a vehicular lamp, flickering of light can be suppressed if the frequency of vibration of the optical path of light irradiated on the irradiated object is about half the frequency (about 30 Hz) of human visual time resolution. In addition, if the frequency of the vibration of the optical path of the light is 30 Hz or more, the temporal resolution of human vision is generally exceeded. Therefore, the flickering of light can be more effectively suppressed. Moreover, if this frequency is 60 Hz or more, the flickering of light can be more effectively suppressed.

In the vehicular lamp of the third aspect, the light distribution pattern forming element is a diffraction grating formed of a diffraction grating pattern formed in each of a plurality of divided areas, and the movable reflecting member is the light May be oscillated at least one of the diffraction grating patterns on the incident surface of the light distribution pattern forming element.

According to such a configuration, since the optical path of the light vibrates at least one of the diffraction grating patterns, the incident angle and phase change of the light incident on the irradiated surface are increased. For this reason, the flicker of light can be suppressed more effectively.

In the case where the diffraction grating pattern is formed of a plurality of diffraction grating patterns, even if the optical path of the light vibrates less than one diffraction grating pattern, the light flicker can be suppressed. Further, the diffraction grating is not necessarily formed from a plurality of diffraction grating patterns, and may be formed from a single diffraction grating pattern.

In the vehicle lamp of the third aspect, the movable reflecting member may vibrate the optical path of the light by swinging the movable reflecting surface around at least one axis. Alternatively, the movable reflecting member may vibrate the optical path of the light by changing the curvature of the movable reflecting surface.

It is a figure which shows an example of the vehicle lamp in 1st Embodiment as a 1st aspect of this invention. It is a front view of the phase modulation element shown in FIG. It is a figure which shows roughly the cross section of the thickness direction of a part of phase modulation element shown in FIG. It is a figure which shows a light distribution pattern. It is a figure which shows the vehicle lamp in 2nd Embodiment as a 1st aspect of this invention similarly to FIG. It is a figure which shows schematically the cross section of the thickness direction of a part of phase modulation element shown in FIG. It is a figure which shows an example of the vehicle lamp in 3rd Embodiment as a 2nd aspect of this invention. It is an enlarged view of the optical system unit shown in FIG. FIG. 9 is a front view of the phase modulation element shown in FIG. 8. It is a figure which shows the optical system unit in 4th Embodiment as a 2nd aspect of this invention similarly to FIG. It is a figure which shows the optical system unit in 5th Embodiment as a 2nd aspect of this invention similarly to FIG. It is a longitudinal cross-sectional view which shows roughly an example of the vehicle lamp which concerns on 6th Embodiment as a 3rd aspect of this invention. It is an enlarged view of the optical system unit shown by FIG. It is a figure which shows roughly an example of the MEMS mirror shown by FIG. It is a figure which shows the laser beam which injects into the diffraction grating shown by FIG. It is a figure explaining operation | movement of the MEMS mirror shown by FIG. It is a figure which shows the outline of the optical system unit in the vehicle headlamp which concerns on 7th Embodiment as a 3rd aspect of this invention similarly to FIG. It is a figure which shows a part of optical system unit in the vehicle headlamp which concerns on 8th Embodiment as a 3rd aspect of this invention similarly to FIG. It is a figure which shows the laser beam which injects into the diffraction grating shown in FIG. 18 similarly to FIG. It is a figure which shows a part of optical system unit of the vehicle lamp which concerns on 9th Embodiment as a 3rd aspect of this invention similarly to FIG.

Hereinafter, the form for implementing the vehicle lamp concerning this invention is illustrated with an accompanying drawing. The embodiments exemplified below are intended to facilitate 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 spirit of the present invention.

(First embodiment)
FIG. 1 is a diagram illustrating an example of a vehicular lamp according to the first embodiment as a first aspect, and is a diagram schematically illustrating a vertical cross section of the vehicular lamp. The vehicular lamp of this embodiment is a vehicular headlamp 1. As shown in FIG. 1, the vehicular headlamp 1 of this embodiment has a casing 10 and a lamp unit 20 as main components. Prepare.

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. In addition, an opening smaller than the front is formed at the rear of the lamp housing 11, and the back cover 13 is fixed to the lamp housing 11 so as to close the opening.

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

The lamp unit 20 of this embodiment includes a light source 21, a phase modulation element 22, a control unit 70, and an input unit 72 as main components. The light source 21, the phase modulation element 22, and the control unit 70 are It is accommodated in the chamber R and fixed to the housing 10 by means (not shown).

The light source 21 emits a plurality of laser beams having different wavelengths from each other in a time-sharing manner. The light source 21 of the present embodiment includes a light emitting element (not shown) that emits red laser light with a power peak wavelength of 638 nm, for example, and a light emitting element (not shown) that emits green laser light with a power peak wavelength of 515 nm, for example. And a light emitting element (not shown) that emits blue laser light having a power peak wavelength of, for example, 445 nm. Electric power is supplied to these light emitting elements via a drive circuit. Moreover, the light source 21 of this embodiment has a collimating lens (not shown) corresponding to each of these light emitting elements. The collimating lens is a lens that collimates the fast axis direction and the slow axis direction of the light emitted from the corresponding light emitting element, and the laser light emitted from these light emitting elements and transmitted through the collimating lens corresponding to each light emitting element is a light source. 21 is emitted. The light source 21 can emit the red laser light LR, the green laser light LG, and the blue laser light LB in a time-sharing manner by adjusting the power supplied to each light emitting element. LR, LG, and LB are applied to substantially the same region of the phase modulation element 22. That is, the light source 21 of the present embodiment switches between the red laser light LR, the green laser light LG, and the blue laser light LB, and the laser light LR, LG, LB of any color is desired at a desired timing. It is configured to be able to emit time. In FIG. 1, the red laser beam LR is indicated by a solid line, the green laser beam LG is indicated by a broken line, the blue laser beam LB is indicated by a one-dot chain line, and the laser beams LR, LG, LB are shifted. Is shown. Moreover, the light source 21 can adjust the intensity | strength of each emitted laser beam LR, LG, LB by adjusting the electric power supplied to each light emitting element. In the present embodiment, the intensities of the laser beams LR, LG, and LB are adjusted so that the color of the combined light of the laser beams LR, LG, and LB is white as an initial state. As the light source 21, for example, a semiconductor laser in which a light emitting element is a laser element that emits laser light can be used.

The phase modulation element 22 is configured to diffract and emit incident light and to change the light distribution pattern of the emitted light. The phase modulation element 22 of the present embodiment is a reflection type phase modulation element that diffracts and emits incident light while reflecting incident light, and is, for example, a liquid crystal panel LCOS (Liquid Crystal On On Silicon). . Laser light LR, LG, LB emitted from the light source 21 is incident on the phase modulation element 22 in a time division manner.

FIG. 2 is a front view of the phase modulation element 22 shown in FIG. In FIG. 2, a region 21A where the laser beams LR, LG, and LB emitted from the light source 21 are incident is indicated by broken lines. The phase modulation element 22 has a rectangular outer shape, and has a plurality of modulation units arranged in a matrix within the rectangle. Each modulation unit diffracts light incident on the modulation unit. Exit. Each modulation unit includes a plurality of dots arranged in a matrix. The modulation unit is formed so as to be positioned one or more in the region 21A where the laser light emitted from the light source 21 is incident. Further, as shown in FIG. 2, a scanning line driving circuit 22H is arranged on the lateral side of the phase modulation element 22, and a data line driving circuit 22V is arranged on one side in the vertical direction of the phase modulation element 22. Yes.

FIG. 3 is a diagram schematically showing a section in the thickness direction of a part of the phase modulation element 22 shown in FIG. As shown in FIG. 3, the phase modulation element 22 of the present embodiment mainly includes a silicon substrate 23, a drive circuit layer 24, a plurality of electrodes 25, a reflective film 26, a liquid crystal layer 27, a transparent electrode 28, and a translucent substrate 29. Prepare as a simple configuration.

The plurality of electrodes 25 are arranged in a matrix corresponding to each dot of the modulation unit on one surface side of the silicon substrate 23, and each dot includes the electrode 25. The drive circuit layer 24 is a layer in which circuits connected to the scanning line drive circuit 22H and the data line drive circuit 22V shown in FIG. 2 are arranged, and is arranged between the silicon substrate 23 and the plurality of electrodes 25. The translucent substrate 29 is disposed on one side of the silicon substrate 23 so as to face the silicon substrate 23, and is a glass substrate, for example. The laser light emitted from the light source 21 is incident from the surface of the translucent substrate 29 opposite to the silicon substrate 23 side. The transparent electrode 28 is disposed on the surface of the translucent substrate 29 on the silicon substrate 23 side. The liquid crystal layer 27 includes liquid crystal molecules 27 a and is disposed between the plurality of electrodes 25 and the transparent electrode 28. The reflective film 26 is disposed between the plurality of electrodes 25 and the liquid crystal layer 27 and is, for example, a dielectric multilayer film. The laser light emitted from the light source 21 is incident from the surface of the translucent substrate 29 opposite to the silicon substrate 23 side.

As shown in FIG. 3, the light LR incident from the surface opposite to the silicon substrate 23 side of the translucent substrate 29 passes through the transparent electrode 28 and the liquid crystal layer 27, is reflected by the reflective film 26, and is reflected by the liquid crystal layer 27 The light passes through the transparent electrode 28 and is emitted from the translucent substrate 29. Here, when a voltage is applied between the specific electrode 25 and the transparent electrode 28, the orientation of the liquid crystal molecules 27 a of the liquid crystal layer 27 located between the electrode 25 and the transparent electrode 28 changes, and the electrode The refractive index of the liquid crystal layer 27 located between 25 and the transparent electrode 28 changes. Since the orientation of the liquid crystal molecules 27a changes according to the applied voltage, the refractive index also changes according to this voltage. As the refractive index of the liquid crystal layer 27 is changed, the optical path length of the light LR transmitted through the liquid crystal layer 27 is changed as described above. Therefore, the light transmitted through the liquid crystal layer 27 and emitted from the phase modulation element 22 is changed. The phase can be changed. As described above, since the plurality of electrodes 25 are arranged corresponding to each dot of the modulation unit, the voltage applied between the electrode 25 corresponding to each dot and the transparent electrode 28 is controlled. Thus, the amount of change in the phase of the light emitted from each dot is adjusted. By adjusting the refractive index of the liquid crystal layer 27 in each dot in this way, the phase modulation element 22 can diffract and emit the incident light and can change the light distribution pattern of the emitted light to a desired light distribution pattern. Moreover, the phase modulation element 22 can change the light distribution pattern of the emitted light by changing the refractive index of the liquid crystal layer 27 in each dot.

In the present embodiment, the same phase modulation pattern is formed in each modulation unit. In the present specification, the phase modulation pattern indicates a pattern for modulating the phase of incident light. In the present embodiment, the phase modulation pattern is a pattern of the refractive index of the liquid crystal layer 27 in each dot, and can be understood as a pattern of a voltage applied between the electrode 25 and the transparent electrode 28 corresponding to each dot. . The phase modulation element 22 of the present embodiment converts the modulation pattern into a phase modulation pattern corresponding to the red laser beam LR, a phase modulation pattern corresponding to the green laser beam LG, and a phase modulation pattern corresponding to the blue laser beam LB. It can be changed. Then, the phase modulation element 22 diffracts and emits each laser beam LR, LG, LB with a phase modulation pattern corresponding to each laser beam LR, LG, LB. In the present embodiment, the phase modulation patterns corresponding to the laser beams LR, LG, and LB are different from each other.

The light DLR diffracted by the phase modulation element 22 and emitted from the phase modulation element 22 is red, and the green laser light LG is diffracted by the phase modulation element 22 and emitted from the phase modulation element 22. The light DLG is green, and the light DLB emitted from the phase modulation element 22 after the blue laser light LB is diffracted by the phase modulation element 22 is blue. In FIG. 1, the red light DLR is indicated by a solid line, the green light DLG is indicated by a broken line, the blue light DLG is indicated by an alternate long and short dash line, and the lights DLR, DLG, and DLB are shifted from each other. Yes. The phase modulation patterns corresponding to the laser beams LR, LG, and LB are arranged so that the regions irradiated with the light DLR, DLG, and DLB are overlapped with each other at a focal position separated from the vehicle by a predetermined distance. The phase modulation pattern diffracts LG and LB. This focal position is, for example, a position 25 m away from the vehicle. In other words, the phase modulation element 22 is configured such that the light distribution pattern of the emitted light DLR, the light distribution pattern of the emitted light DLG, and the light distribution pattern of the emitted light DLB are at a focal position at a predetermined distance from the vehicle. Lights DLR, DLG, and DLB are emitted so as to overlap each other. As described above, the phase modulation element 22 has a plurality of modulation units that form the same phase modulation pattern, and the laser beams LR that are incident so that each modulation unit has such a light distribution pattern, LG and LB are diffracted, respectively.

Specifically, the phase modulation element 22 emits red light emitted from the light source 21 so that light obtained by combining the respective lights DLR, DLG, and DLB emitted from the phase modulation element 22 has a low beam distribution pattern. The laser beam LR, the green laser beam LG, and the blue laser beam LB are diffracted, respectively. Each light distribution pattern includes an intensity distribution. For this reason, the phase modulation element 22 of the present embodiment has the light distribution DLR, DLG, DLB emitted from the phase modulation element 22 superimposed on the light distribution pattern of the low beam and the intensity distribution based on the intensity distribution of the light distribution pattern of the low beam. Thus, the red laser light LR, the green laser light LG, and the blue laser light LB that are emitted from the light source 21 and incident on the phase modulation element 22 are diffracted, respectively. Thus, the phase modulation element 22 emits the red component light DLR of the low beam light distribution pattern, the green component light DLG of the low beam light distribution pattern, and the blue component light DLB of the low beam light distribution pattern.

The intensity distribution based on the intensity distribution of the low beam light distribution pattern is that the intensity of the light DLR, DLG, and DLB emitted from the phase modulation element 22 is high at a portion where the intensity of the low beam light distribution pattern is high. It means that.

The input unit 72 shown in FIG. 1 outputs information such as a command and a set value input according to a user's operation using an electrical signal. In the present embodiment, the information input to the input unit 72 includes the intensity of each of the laser beams LR, LG, LB emitted from the light source 21 and the length of each emission time of the laser beams LR, LG, LB. The Examples of the input unit 72 include a switch group in which a plurality of rotary switches are mounted on a circuit board.

As shown in FIG. 2, the control unit 70 is electrically connected to the scanning line driving circuit 22H and the data line driving circuit 22V of the phase modulation element 22, and controls the refractive index of the liquid crystal layer 27 in each dot. The control unit 70 is electrically connected to the light source 21 and controls the emission state of the laser light from the light source 21. The control unit 70 performs these controls based on a signal input to the control unit 70 from the outside. In the present embodiment, the control unit 70 is electrically connected to a control device 71 such as an ECU (electronic control device) of the vehicle, an input unit 72, and the like.

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

For example, when the control unit 70 detects a signal indicating low beam irradiation from the vehicle control device 71 and the signal is input to the control unit 70, the laser light emission state of the light source 21 is detected. And the refractive index of the liquid crystal layer 27 at each dot of the phase modulation element 22 are controlled to emit light from the vehicle headlamp 1. The controller 70 controls the state of laser light emitted from the light source 21 by driving the drive circuit of the light source 21. In addition, the control unit 70 controls the refractive index of the liquid crystal layer 27 in each dot of the phase modulation element 22 by adjusting the voltage applied between the electrode 25 corresponding to each dot and the transparent electrode 28. .

Specifically, the control unit 70 of the present embodiment uses the phase modulation pattern in which the red laser light LR emitted from the light source 21 is a phase modulation pattern in which the phase modulation pattern in the modulation unit corresponds to the red laser light LR. The light source 21 and the phase modulation element 22 are controlled so as to enter the element 22. That is, the control unit 70 emits the red laser light LR from the light source 21 for a predetermined time while making the phase modulation pattern in the modulation unit of the phase modulation element 22 a phase modulation pattern corresponding to the red laser light LR. Note that the control unit 70 may change the phase modulation pattern of the phase modulation element 22 and emit the red laser light LR from the light source 21 at the same timing, or may perform them at different timings. Is not particularly limited. The red laser light LR emitted from the light source 21 in this manner is diffracted as described above by the phase modulation element 22 in this state, and the red component light DLR of the low beam light distribution pattern is given from the phase modulation element 22 to a predetermined value. Emits time. The red component light DLR of the low beam light distribution pattern is emitted from the vehicle headlamp 1 through the front cover 12 for a predetermined time.

Next, the control unit 70 causes the green laser light LG emitted from the light source 21 to enter the phase modulation element 22 whose phase modulation pattern in the modulation unit is a phase modulation pattern corresponding to the green laser light LG. In addition, the light source 21 and the phase modulation element 22 are controlled. That is, the control unit 70 emits the green laser light LG from the light source 21 for a predetermined time while making the phase modulation pattern in the modulation unit of the phase modulation element 22 a phase modulation pattern corresponding to the green laser light LG. Similar to the case where the red component light DLR of the low beam distribution pattern is emitted from the phase modulation element 22, the control unit 70 changes the phase modulation pattern of the phase modulation element 22 and emits the green laser light LG from the light source 21. May be performed at the same timing, or may be performed at different timings. The green laser light LG emitted from the light source 21 in this manner is diffracted as described above by the phase modulation element 22 in this state, and the green component light DLG of the low beam light distribution pattern is predetermined from the phase modulation element 22. Emits time. The green component light DLG of the low beam light distribution pattern is emitted from the vehicle headlamp 1 through the front cover 12 for a predetermined time.

Next, the control unit 70 causes the blue laser light LB emitted from the light source 21 to enter the phase modulation element 22 in which the phase modulation pattern in the modulation unit is a phase modulation pattern corresponding to the blue laser light LB. In addition, the light source 21 and the phase modulation element 22 are controlled. That is, the control unit 70 emits the blue laser light LB from the light source 21 for a predetermined time while making the phase modulation pattern in the modulation unit of the phase modulation element 22 a phase modulation pattern corresponding to the blue laser light LB. Similarly to the case where the red component light DLR of the low beam distribution pattern is emitted from the phase modulation element 22, the control unit 70 changes the phase modulation pattern of the phase modulation element 22 and emits the blue laser light LB from the light source 21. May be performed at the same timing, or may be performed at different timings. The blue laser light LB emitted from the light source 21 in this manner is diffracted as described above by the phase modulation element 22 in this state, and the blue component light DLB of the low beam light distribution pattern is predetermined from the phase modulation element 22. Emits time. The blue component light DLB of the low beam light distribution pattern is emitted from the vehicle headlamp 1 through the front cover 12 for a predetermined time.

The control unit 70 changes the phase modulation pattern of the phase modulation element 22 and emits the red laser light LR from the light source 21, changes the phase modulation pattern of the phase modulation element 22, and the green laser light LG from the light source 21. , The change of the phase modulation pattern of the phase modulation element 22, and the emission of the blue laser light LB from the light source 21 are sequentially repeated, and the refractive index of the liquid crystal layer 27 in each dot of the phase modulation element 22 and the light source 21. Controls the state of laser light emission. That is, the emission of the red laser light LR, the green laser light LG, and the blue laser light LB in the time division of the light source 21 and the change of the phase modulation pattern of the phase modulation element 22 are synchronized. From the vehicle headlamp 1, the red component light DLR of the low beam light distribution pattern, the green component light DLG of the low beam light distribution pattern, and the blue component light DLB of the low beam light distribution pattern are sequentially repeated. Are emitted. In the present embodiment, since the lengths of the emission times of the laser beams LR, LG, and LB are substantially the same, the lengths of the emission times of the lights DLR, DLG, and DLB are also substantially the same.

By the way, when light of different colors is repeatedly irradiated with a period shorter than the temporal resolution of human vision, the person can recognize that the light of the different colors is irradiated by the afterimage phenomenon. In the present embodiment, when the time from when the laser beam of a predetermined color is emitted until the laser beam of the predetermined color is emitted again is shorter than the temporal resolution of human vision, the temporal resolution of human vision The light DLR, DLG, DLB emitted from the phase modulation element 22 with a shorter cycle is repeatedly irradiated, and the red light DLR, the green light DLG, and the blue light DLB are combined by an afterimage phenomenon. The lengths of the emission times of the light DLR, DLG, and DLB are substantially the same. Further, as described above, the intensities of the respective laser beams LR, LG, and LB are adjusted so that the color of the combined light of the laser beams LR, LG, and LB becomes white as described above. For this reason, the color of the light synthesized by the afterimage phenomenon is white. Each of the lights DLR, DLG, DLB overlaps with the low beam light distribution pattern as described above, and has an intensity distribution based on the intensity distribution of the low beam light distribution pattern. For this reason, the light distribution pattern of light in which the light DLR, DLG, and DLB are combined by the afterimage phenomenon becomes a low beam light distribution pattern. In addition, it is preferable that the period which repeats | emits said laser beam LR, LG, LB is set to 1/15 s or less from a viewpoint of suppressing feeling of the flicker of the light synthesize | combined by an afterimage phenomenon. The human visual temporal resolution is approximately 1/30 s. If it is a vehicle lamp, if the light emission cycle is about twice, it is possible to suppress the feeling of flickering of light. If this period is 1/30 s or less, it substantially exceeds the temporal resolution of human vision. Therefore, it is possible to further suppress the feeling of light flicker. Further, from the viewpoint of further suppressing the feeling of flickering of light, this period is preferably 1/60 s or less.

Thus, the vehicle headlamp 1 can irradiate light having a low beam light distribution pattern by an afterimage phenomenon.

FIG. 4 is a diagram showing a light distribution pattern for night illumination. Specifically, FIG. 4A is a diagram showing a low beam light distribution pattern, and FIG. 4B is a diagram showing a high beam light distribution pattern. FIG. In FIG. 4, S indicates a horizontal line, and a light distribution pattern is indicated by a thick line. Of the low beam light distribution pattern PTN _L , which is the light distribution pattern for night illumination shown in FIG. 4A, the region LA1 is the region with the highest intensity, and the intensity decreases in the order of the region LA2 and the region LA3. That is, the phase modulation element 22 diffracts the light so that the light synthesized by the afterimage phenomenon forms a light distribution pattern including a low beam intensity distribution. Note that, as indicated by a broken line in FIG. 4, light having a lower intensity than the low beam may be emitted from the vehicle headlamp 1 above the position where the low beam is irradiated by the afterimage phenomenon. This light is used as a light OHS for visually recognizing a sign. In this case, the light distribution pattern of the light DLR, DLG, and DLB emitted from the phase modulation element 22 overlaps with the region irradiated with the marker visual recognition light OHS and includes an intensity distribution of the optical signal OHS for visual recognition of the marker. A light pattern is preferably included. Further, the light distribution pattern of the light DLR, DLG, DLB includes an intensity distribution of the light OHS for visually recognizing the sign so that the external shape matches at least a part of the external shape of the region irradiated with the light OHS for visually recognizing the sign. More preferably, a light pattern is included. Furthermore, it is more preferable that this outer shape matches the entire outer shape of the region irradiated with the light OHS for visually recognizing the sign. In this case, it can be understood that a light distribution pattern for night illumination is formed by the low beam and the light OHS for visually recognizing the sign. The light distribution pattern for night illumination is not used only at night, but is also used in a dark place such as a tunnel.

Next, adjustment of the light color balance in the vehicle headlamp 1 will be described.

As described above, the input unit 72 is electrically connected to the control unit 70, and the control unit 70 has the intensities of the laser beams LR, LG, and LB emitted from the light source 21 and the laser beam LR. , LG, and LB are input from the input unit 72 as electrical signals.

Incidentally, the light synthesized by the afterimage phenomenon as described above changes the color balance of the light by changing the intensity of the synthesized light and the length of the emission time of the synthesized light. In the present embodiment, the input unit 72 can adjust the intensity of each of the laser beams LR, LG, LB emitted from the light source 21 and the length of each emission time of the laser beams LR, LG, LB. . For this reason, the color balance of the irradiated light can be adjusted without taking measures such as replacing the light source 21.

Specifically, in the present embodiment, for example, the intensity of the red laser light LR is greater than the intensity in a state in which light having the low beam light distribution pattern PTN _L is irradiated from the vehicle headlamp 1 by the afterimage phenomenon. When the height is increased, the color of the white light having the low beam light distribution pattern PTN _L irradiated from the vehicle headlamp 1 is changed to a color in which red is enhanced. Similarly, when the intensity of the green laser beam LG is increased, the color of the white light is changed to a color in which green is increased, and when the intensity of the blue laser beam LB is increased, the white color of white light is changed. The color of the light is changed to a color in which blue is enhanced. On the other hand, when the intensity of the red laser light LR is lowered, the color of the white light is changed to a color in which bluish green is enhanced, and when the intensity of the green laser light LG is lowered, the white light is changed. Is changed to a color in which reddish purple is enhanced, and when the intensity of the blue laser beam LB is lowered, the color of white light is changed to a color in which yellow is enhanced.

Further, in the present embodiment, the length of the emission time of the red laser light LR is set to the length of the emission time in a state where the light having the low beam distribution pattern PTN _L is irradiated from the vehicle headlamp 1 by the afterimage phenomenon. If it is longer than this, the color of the white light having the low beam distribution pattern PTN _L emitted from the vehicle headlamp 1 is changed to a color in which red is enhanced. Similarly, when the emission time of the green laser beam LG is increased, the color of the white light is changed to a color in which green is enhanced, and when the emission time of the blue laser beam LB is increased, The color of white light is changed to a color in which blue is enhanced. On the other hand, when the emission time of the red laser beam LR is shortened, the color of the white light is changed to a color in which blue-green is enhanced, and when the emission time of the green laser beam LG is shortened, the white color is changed to white. The color of the light is changed to a color in which reddish purple is enhanced, and when the emission time of the blue laser light LB is shortened, the color of the white light is changed to a color in which yellow is enhanced.

Incidentally, white reference light is incident from the light source on the hologram element of the vehicle lamp disclosed in Patent Document 1, and a predetermined light distribution pattern such as a low beam or a high beam is formed by the diffracted light. However, white light is light obtained by combining light of a plurality of wavelengths. Incidentally, a hologram element which is a kind of diffraction grating has wavelength dependency. Therefore, light of different wavelengths contained in white tends to have different light distribution patterns depending on the hologram element. For this reason, in the vehicular lamp described in Patent Document 1, bleeding of light from which different colors of light emerge near the edge of the formed light distribution pattern.

Therefore, the vehicle headlamp 1 of the present embodiment as the first aspect includes a light source 21 and a phase modulation element 22. The phase modulation element 22 can change the light distribution pattern of the emitted light while diffracting and emitting the incident light. The light source 21 emits red laser light LR, green laser light LG, and blue laser light LB in a time-sharing manner. The laser beams LR, LG, and LB emitted from the light source 21 are incident on the phase modulation element 22, and the phase modulation element 22 has a phase modulation pattern corresponding to each of the laser beams LR, LG, and LB. LG and LB are diffracted and emitted. The regions irradiated with the light DLR, DLG, DLB emitted from the phase modulation element 22 corresponding to the respective laser beams LR, LG, LB overlap each other.

As described above, when light of different colors is repeatedly emitted with a period shorter than the human visual temporal resolution, the person recognizes that the light of the different colors is irradiated by the afterimage phenomenon. obtain. Therefore, when the red laser beam LR, the green laser beam LG, and the blue laser beam LB are repeatedly emitted from the light source 21 at a cycle shorter than the temporal resolution of human vision, the vehicle headlamp 1 is White light obtained by combining the red laser light LR, the green laser light LG, and the blue laser light LB emitted from the light source 21 may be irradiated by an afterimage phenomenon.

Moreover, in the vehicle headlamp 1 of the present embodiment as the first aspect, as described above, the phase modulation element 22 has the phase modulation pattern corresponding to the laser beams LR, LG, and LB of the respective wavelengths. Laser beams LR, LG, and LB are diffracted and emitted. For this reason, the light distribution patterns of the light DLR, DLG, and DLB emitted from the phase modulation element 22 corresponding to the laser beams LR, LG, and LB of the respective wavelengths can be changed to desired light distribution patterns. Therefore, the vehicle headlamp 1 of the present embodiment as the first mode is irradiated with the light DLR, DLG, DLB emitted from the phase modulation element 22 corresponding to the laser beams LR, LG, LB of the respective wavelengths. It is possible to suppress the deviation of the outer shape of the region to be generated, and it is possible to suppress the occurrence of color bleeding near the edge of the low beam light distribution pattern PTN _L formed by the afterimage phenomenon.

From the viewpoint of suppressing color blurring near the edge of the low-beam light distribution pattern PTN _L , the phase modulation element 22 emits light DLR, DLG, DLB at a focal position that is a predetermined distance away from the vehicle. It is preferable that the laser beams LR, LG, and LB be diffracted to emit the light beams DLR, DLG, and DLB so that at least a part of the outer shape of the regions to be matched with each other. That is, the phase modulation element 22 emits the laser beams LR, LG, and LB so that at least a part of the outer shape of the light distribution pattern of the light DLR, DLG, and DLB matches each other at a focal position that is a predetermined distance away from the vehicle. It is preferable that the light DLR, DLG, and DLB are emitted after being diffracted. In other words, the phase modulation pattern corresponding to each laser beam LR, LG, LB is such that at least a part of the outer shape of the region irradiated with the light DLR, DLG, DLB is mutually at a focal position that is a predetermined distance away from the vehicle. A phase modulation pattern that diffracts the respective laser beams LR, LG, and LB so as to coincide with each other is preferable. With such a configuration, it is possible to suppress the occurrence of color bleeding near the edge of the low beam light distribution pattern PTN _L formed by the afterimage phenomenon as described above. Further, from the viewpoint of further suppressing the occurrence of color bleeding near the edge of the low beam light distribution pattern PTN _L , it is more preferable that the whole of these outer shapes match each other.

Further, as described above, the vehicle headlamp 1 according to the present embodiment as the first aspect includes the red laser light LR, the green laser light LG, and the blue laser light LB emitted from the light source 21. The synthesized white light can be irradiated by the afterimage phenomenon. The color balance of the light synthesized by the afterimage phenomenon is adjusted by adjusting the intensity of each laser beam LR, LG, LB emitted from the light source 21 and the length of the emission time of each laser beam LR, LG, LB. It can be adjusted by doing. Therefore, the vehicle headlamp 1 of the present embodiment as the first aspect can adjust the color balance without taking measures such as replacing the light source 21.

(Second Embodiment)
Next, a second embodiment as the first aspect of the present invention will be described in detail with reference to FIGS. FIG. 5 is a view showing the vehicular lamp in the second embodiment as the first aspect of the present invention in the same manner as FIG. 1, and FIG. 6 is a partial thickness direction of the phase modulation element shown in FIG. FIG. In addition, about the component which is the same as that of 1st Embodiment, or equivalent, except the case where it demonstrates especially, the same referential mark is attached | subjected and the overlapping description is abbreviate | omitted.

As shown in FIGS. 5 and 6, in the present embodiment, the vehicular lamp is a vehicular headlamp 1 as in the first embodiment. Further, the vehicle headlamp 1 of the present embodiment is a vehicle of the first embodiment in that it is a transmission type phase modulation element that mainly diffracts and emits the light incident on the phase modulation element 22. Different from the headlamp 1 for use.

In the present embodiment, the phase modulation element 22 is, for example, an LCD (Liquid Crystal Display) that is a transmissive liquid crystal panel, and laser light LR, LG, LB emitted from the light source 21 is received in the phase modulation element 22. Incident in time division. Similar to the phase modulation element 22 of the first embodiment, the phase modulation element 22 of the present embodiment has a rectangular outer shape, and has a plurality of modulation units arranged in a matrix within the rectangle. . Each modulation unit includes a plurality of dots arranged in a matrix. The modulation unit is formed so as to be positioned one or more in the region 21A where the laser light emitted from the light source 21 is incident.

As shown in FIG. 6, the phase modulation element 22 of the present embodiment is mainly provided with a translucent substrate 23 a instead of the silicon substrate 23, a point provided with a plurality of transparent electrodes 25 a instead of the plurality of electrodes 25, It differs from the phase modulation element 22 of the first embodiment in that the reflection film 26 is not provided. The phase modulation element 22 of the present embodiment includes a pair of translucent substrates 23a and 29, a drive circuit layer 24, a plurality of transparent electrodes 25a, a liquid crystal layer 27, and a transparent electrode 28 as main components.

The plurality of transparent electrodes 25a are arranged in a matrix corresponding to each dot of the modulation unit on one surface side of one translucent substrate 23a, and each dot includes the transparent electrode 25a. . The drive circuit layer 24 is disposed between the translucent substrate 23a and the plurality of transparent electrodes 25a. The other translucent substrate 29 is disposed so as to face the one translucent substrate 23a on one surface side of the one translucent substrate 23a. The laser light emitted from the light source 21 is incident on the surface of the other light-transmitting substrate 29 opposite to the one light-transmitting substrate 23a. The transparent electrode 28 is disposed on the surface of the other translucent substrate 29 on the one translucent substrate 23a side. The liquid crystal layer 27 includes liquid crystal molecules 27 a and is disposed between the plurality of transparent electrodes 25 a and the transparent electrodes 28. In this embodiment, the laser light emitted from the light source 21 is incident on the surface of the other translucent substrate 29 opposite to the one translucent substrate 23a.

As shown in FIG. 6, the light LR incident from the surface opposite to the one light transmissive substrate 23 a side of the other light transmissive substrate 29 is transmitted through the transparent electrode 28, the liquid crystal layer 27, the transparent electrode 25 a, The light passes through the translucent substrate 23a and is emitted from the surface of the one translucent substrate 23a opposite to the other translucent substrate 29 side. When a voltage is applied between the specific transparent electrode 25a and the transparent electrode 28, the orientation of the liquid crystal molecules 27a of the liquid crystal layer 27 located between the transparent electrode 25a and the transparent electrode 28 changes, and the transparent electrode The refractive index of the liquid crystal layer 27 located between 25a and the transparent electrode 28 changes. Since the orientation of the liquid crystal molecules 27a changes according to the applied voltage, the refractive index also changes according to this voltage. As the refractive index of the liquid crystal layer 27 is changed, the optical path length of the light LR transmitted through the liquid crystal layer 27 is changed as described above. Therefore, the light transmitted through the liquid crystal layer 27 and emitted from the phase modulation element 22 is changed. The phase can be changed. Since the plurality of transparent electrodes 25a are arranged corresponding to the respective dots of the modulation unit, the voltage applied between the transparent electrode 25a corresponding to each dot and the transparent electrode 28 is controlled. The amount of change in the phase of the light emitted from the dots is adjusted. Similarly to the phase modulation element 22 of the first embodiment, the phase modulation element 22 of the present embodiment adjusts the refractive index of the liquid crystal layer 27 in each dot, thereby diffracting and emitting incident light. The light distribution pattern can be changed to a desired light distribution pattern. Further, the phase modulation element 22 of the present embodiment can change the light distribution pattern of the emitted light by changing the refractive index of the liquid crystal layer 27 in each dot. The phase modulation element 22 emits light from the other light transmissive substrate 29 when light is incident from the one light transmissive substrate 23a side. Even in this case, the phase modulation element 22 can change the light distribution pattern of the emitted light to a desired light distribution pattern by adjusting the refractive index of the liquid crystal layer 27 in each dot.

In the phase modulation element 22 of the present embodiment, the same phase modulation pattern is formed in each modulation unit, similarly to the phase modulation element 22 of the first embodiment. The phase modulation element 22 can change the modulation pattern to a phase modulation pattern corresponding to the red laser light LR, a phase modulation pattern corresponding to the green laser light LG, and a phase modulation pattern corresponding to the blue laser light LB. It is said that. In the present embodiment, the phase modulation patterns corresponding to the laser beams LR, LG, and LB are different from each other.

The control unit 70 is configured so that the emission of the red laser light LR, the green laser light LG, and the blue laser light LB in the time division of the light source 21 and the change of the phase modulation pattern of the phase modulation element 22 are synchronized. 21 and the phase modulation element 22 are controlled. Therefore, similarly to the description in the first embodiment, the phase modulation element 22 diffracts each laser beam LR, LG, LB with a phase modulation pattern corresponding to each incident laser beam LR, LG, LB. Then, light DLR, DLG, and DLB are emitted. Thus, from the vehicle headlamp 1, the light distribution pattern PTN blue component light DLG light distribution pattern PTN _L of the low beam of the green component of the light distribution pattern PTN _L optical DLR and low beam of the red component of the _L low beam Light DLB is emitted sequentially and repeatedly. Even in such a configuration, when the red laser beam LR, the green laser beam LG, and the blue laser beam LB are repeatedly emitted at a cycle shorter than the temporal resolution of human vision, the vehicle headlamp is used. The lamp 1 can irradiate light having a low beam light distribution pattern PTN _L by an afterimage phenomenon. Further, the phase modulation element 22 diffracts and emits the laser beams LR, LG, and LB with a phase modulation pattern corresponding to the laser beams LR, LG, and LB of the respective wavelengths. For this reason, the vehicle headlamp 1 of the present embodiment has an outer shape of a region irradiated with the light DLR, DLG, DLB emitted from the phase modulation element 22 corresponding to the laser beams LR, LG, LB of the respective wavelengths. Can be suppressed, and the occurrence of color blurring in the vicinity of the edge of the low-beam light distribution pattern PTN _L formed by the afterimage phenomenon can be suppressed. The color balance of the light emitted by the afterimage phenomenon is adjusted by adjusting the intensity of each laser beam LR, LG, LB emitted from the light source 21 and the length of the emission time of each laser beam LR, LG, LB. Can be adjusted. Therefore, the vehicle headlamp 1 of the present embodiment can adjust the color balance without taking measures such as replacing the light source 21.

In this embodiment, as shown by a broken line in FIG. 4, the light OHS for sign visual recognition may be emitted. In this case, the light distribution pattern of the light DLR, DLG, and DLB emitted from the phase modulation element 22 overlaps with the region irradiated with the marker visual recognition light OHS and includes an intensity distribution of the optical signal OHS for visual recognition of the marker. A light pattern is preferably included. Further, the light distribution pattern of the light DLR, DLG, DLB includes an intensity distribution of the light OHS for visually recognizing the sign so that the external shape matches at least a part of the external shape of the region irradiated with the light OHS for visually recognizing the sign. More preferably, a light pattern is included. Furthermore, it is more preferable that this outer shape matches the entire outer shape of the region irradiated with the light OHS for visually recognizing the sign.

In the first and second embodiments as the first aspect, the vehicle headlamp 1 as the vehicle lamp is assumed to irradiate the low beam by the afterimage phenomenon, but as the first aspect of the present invention, The vehicle lamp is not particularly limited. For example, the vehicular lamp as the first aspect may be irradiated with a high beam by an afterimage phenomenon, or may be irradiated with light constituting an image by an afterimage phenomenon. If the vehicle lamp is intended to irradiate a high beam by afterimage phenomenon is illuminated by light distribution pattern PTN _H light afterimage of the high beam light distribution pattern is a light distribution pattern for nighttime illumination shown in FIG. 4 (B) . Note that, in the high beam light distribution pattern PTN _H in FIG. 4B, the region HA1 is a region having the highest intensity, and the region HA2 is a region having a lower intensity than the region HA1. That is, the phase modulation element 22 diffracts the light so that the light synthesized by the afterimage phenomenon forms a light distribution pattern including the high beam intensity distribution. Further, when the vehicular lamp irradiates light constituting the image by an afterimage phenomenon, the direction of the light emitted from the vehicular lamp and the position where the vehicular lamp is attached to the vehicle are not particularly limited.

In the first and second embodiments as the first mode, the light source 21 that emits the red laser beam LR, the green laser beam LG, and the blue laser beam LB in a time-division manner is described as an example. However, the light source only needs to be able to emit a plurality of laser beams having different wavelengths in a time division manner. For example, the light source may emit two laser beams having different wavelengths in a time division manner. Two or more laser beams may be emitted in a time division manner.

In the first and second embodiments as the first aspect, the vehicle headlamp 1 as a vehicle lamp including the input unit 72 has been described as an example. However, the vehicular lamp may not include the input unit 72. In such a case, for example, the control unit determines whether or not the laser light is emitted from the light source on the basis of a predetermined setting value related to the intensity of the laser light emitted from the light source, the length of the laser light emission time, or the like. Control the state. By adjusting this predetermined set value when manufacturing a vehicular lamp, etc., the intensity of the laser beam emitted from the light source and the length of the emission time of the laser beam can be adjusted. The color balance of the emitted light can be adjusted. Therefore, the vehicular lamp having such a configuration can adjust the color balance without taking measures such as replacing the light source.

In the first and second embodiments as the first mode, the phase modulation element 22 having a plurality of modulation units has been described as an example. However, the number, size, outer shape and the like of the modulation unit are not particularly limited. For example, the phase modulation element 22 may have one modulation unit, and incident light may be diffracted by the one modulation unit.

In the first and second embodiments as the first mode, the phase modulation patterns corresponding to the laser beams LR, LG, and LB are different from each other. However, the phase modulation pattern corresponding to the laser beam of each wavelength diffracts each laser beam so that the regions irradiated with the light emitted from the phase modulation element corresponding to the laser beam of each wavelength overlap each other. It is sufficient that the phase modulation pattern to be generated is used. For example, as a result of using the phase modulation pattern corresponding to the laser beam of each wavelength as such a phase modulation pattern, some of the phase modulation patterns may be the same.

Also, in the first embodiment as the first mode, the reflection type phase modulation element 22 has been described as an example, and in the second embodiment, the transmission type phase modulation element 22 has been described as an example. However, the phase modulation element only needs to be able to change the light distribution pattern of the emitted light while diffracting and emitting the incident light. For example, the phase modulation element may be a GLV (Grating Light Valve) in which a plurality of reflectors are formed on a silicon substrate. The GLV is a reflection type phase modulation element, and by electrically controlling the deflection of the reflector, the incident light is diffracted and emitted, and the light distribution pattern of the emitted light can be changed.

(Third embodiment)
Next, a third embodiment as the second aspect of the present invention will be described. In addition, about the component which is the same as that of the said 1st Embodiment, or the case where it demonstrates especially, the same referential mark is attached | subjected and the overlapping description is abbreviate | omitted. FIG. 7 is a diagram showing an example of a vehicle lamp in the present embodiment as the second mode, and is a diagram schematically showing a vertical section of the vehicle lamp. As in the first embodiment, the vehicular lamp of this embodiment is a vehicular headlamp 1, and as shown in FIG. 7, the vehicular headlamp 1 of the present embodiment has a configuration of a lamp unit 20. The difference is mainly different from the vehicle headlamp 1 of the first embodiment.

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

The heat sink 30 has a metal base plate 31 extending in a substantially horizontal direction, and a plurality of radiating fins 32 are provided integrally with the base plate 31 on the lower surface side of the base plate 31. The cooling fan 35 is disposed with a clearance from the heat 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.

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

FIG. 8 is an enlarged view of the optical system unit shown in FIG. As shown in FIG. 8, the first light-emitting optical system 51R includes a first light source 52R, a first collimator lens 53R, and a phase modulation element 54R. The first light source 52R is a laser element that emits a laser beam having a predetermined wavelength. In this embodiment, the first light source 52R emits a red laser beam having a power peak wavelength of, for example, 638 nm. The optical system unit 50 has a circuit board (not shown), and the first light source 52R is mounted on the circuit board, and power is supplied through the circuit board.

The first collimating lens 53R is a lens that collimates the fast axis direction and the slow axis direction of the laser light emitted from the first light source 52R. Instead of the first collimating lens 53R, a collimating lens for collimating the fast axis direction of the laser light and a collimating lens for collimating the slow axis direction may be provided separately.

The phase modulation element 54R diffracts and emits incident light, and can change a light distribution pattern of the emitted light and a region irradiated with the emitted light. The phase modulation element 54R of the present embodiment is a reflection type phase modulation element that diffracts and emits incident light while reflecting incident light. For example, the phase modulation element 54R is an LCOS like the phase modulation element 22 of the first embodiment. The Red laser light emitted from the first collimating lens 53R is incident on the phase modulation element 54R, and the phase modulation element 54R diffracts and emits the red laser light. Thus, the red first light DLR is emitted from the phase modulation element 54R, and this light DLR is emitted from the first light emitting optical system 51R.

The second light emitting optical system 51G includes a second light source 52G, a second collimating lens 53G, and a phase modulation element 54G. The third light emitting optical system 51B includes a third light source 52B, a third collimating lens 53B, And a phase modulation element 54B. The light sources 52G and 52B are laser elements that each emit laser light having a predetermined wavelength. In the present embodiment, the second light source 52G emits green laser light having a power peak wavelength of 515 nm, for example, and the third light source 52B emits blue laser light having a power peak wavelength of 445 nm, for example. The light sources 52G and 52B are each mounted on the circuit board, and power is supplied through the circuit board.

The second collimating lens 53G is a lens that collimates the fast axis direction and the slow axis direction of the laser light emitted from the second light source 52G, and the third collimating lens 53B is the fast axis of the laser light emitted from the third light source 52B. This lens collimates the direction and slow axis direction. Instead of these collimating lenses 53G and 53B, a collimating lens for collimating the fast axis direction of the laser light and a collimating lens for collimating the slow axis direction may be provided separately.

Similarly to the phase modulation element 54R, the phase modulation element 54G and the phase modulation element 54B can change the distribution pattern of the emitted light and the region irradiated with the emitted light, while diffracting and emitting the incident light. Has been. These phase modulation elements 54G and 54B are, for example, LCOS which is a reflective liquid crystal panel. Green laser light emitted from the second collimating lens 53G is incident on the phase modulation element 54G, and the phase modulation element 54G diffracts and emits the green laser light. The blue laser light emitted from the third collimating lens 53B is incident on the phase modulation element 54B, and the phase modulation element 54B diffracts and emits the blue laser light. Thus, the green second light DLG is emitted from the phase modulation element 54G, and this light DLG is emitted from the second light-emitting optical system 51G. Further, the blue third light DLB is emitted from the phase modulation element 54B, and this light DLB is emitted from the third light-emitting optical system 51B.

The synthetic optical system 55 includes a first optical element 55f and a second optical element 55s. The first optical element 55f is an optical element that synthesizes the first light DLR emitted from the first light emitting optical system 51R and the second light DLG emitted from the second light emitting optical system 51G. In the present embodiment, the first optical element 55f synthesizes the first light DLR and the second light DLG by transmitting the first light DLR and reflecting the second light DLG. The second optical element 55s is an optical that combines the first light DLR and the second light DLG synthesized by the first optical element 55f and the third light DLB emitted from the third light-emitting optical system 51B. It is an element. In the present embodiment, the second optical element 55s transmits the first light DLR and the second light DLG synthesized by the first optical element 55f and reflects the third light DLB, thereby reflecting the first light. The DLR, the second light DLG, and the third light DLB are combined. Examples of the first optical element 55f and the second optical element 55s include a wavelength selection filter in which an oxide film is stacked on a glass substrate. By controlling the type and thickness of the oxide film, it is possible to transmit light having a wavelength longer than a predetermined wavelength and reflect light having a wavelength shorter than this wavelength.

Thus, the combined optical system 55 emits light in which the first light DLR, the second light DLG, and the third light DLB are combined. 7 and 8, the first light DLR is indicated by a solid line, the second light DLG is indicated by a broken line, and the third light DLB is indicated by a one-dot chain line. These light DLR, DLG, DLB Shown staggered.

The cover 59 is fixed on the base plate 31 of the heat sink 30. The cover 59 has a substantially rectangular shape and is made of a metal such as aluminum. In the space inside the cover 59, the first light emitting optical system 51R, the second light emitting optical system 51G, the third light emitting optical system 51B, and the combining optical system 55 are arranged. In addition, an opening 59H through which light emitted from the combining optical system 55 can be transmitted is formed in front of the cover 59. Note that the inner wall of the cover 59 is preferably light-absorbing by black anodizing or the like. By making the inner wall of the cover 59 light-absorbing, it is possible to prevent light irradiated to the inner wall of the cover 59 from being reflected or refracted unintentionally and being emitted from the opening 59H in an unintended direction. .

Here, in the present embodiment, the phase modulation element 54R, the phase modulation element 54G, and the phase modulation element 54B have the same configuration, and the phase modulation elements 54R, 54G, and 54B are the same as those shown in FIGS. The configuration is the same as that of the phase modulation element 22 in one embodiment.

FIG. 9 is a front view of the phase modulation element shown in FIG. In FIG. 9, a region 53A where the laser light emitted from the first collimating lens 53R is incident is indicated by a broken line. Similarly to the phase modulation element 22 in the first embodiment, the phase modulation element 54R has a rectangular outer shape and includes a plurality of modulation units arranged in a matrix within the rectangle. Diffracts and emits light incident on the modulation unit. Each modulation unit includes a plurality of dots arranged in a matrix. The modulation unit is formed so as to be located at least one in the region 53A where the laser light emitted from the first collimating lens 53R is incident. As shown in FIG. 9, a scanning line driving circuit 22H is arranged on the lateral side of the phase modulation element 54R, and a data line driving circuit 22V is arranged on one side in the vertical direction of the phase modulation element 54R. Yes.

Similar to the phase modulation element 22 in the first embodiment, the phase modulation element 54R adjusts the refractive index of the liquid crystal layer 27 in each dot, thereby diffracting and emitting incident light. The light distribution pattern can be changed to a desired light distribution pattern. In addition, the phase modulation element 54R changes the refractive index of the liquid crystal layer 27 in each dot, thereby changing the light distribution pattern of the emitted light, or changing the direction of the emitted light and irradiating this light. Can be changed.

Similarly to the phase modulation element 22 in the first embodiment, the control unit 70 is electrically connected to the scanning line drive circuit 22H and the data line drive circuit 22V of the phase modulation element 54R. Controls the refractive index of the liquid crystal layer 27 in each dot. The control unit 70 is also electrically connected to a scanning line drive circuit and a data line drive circuit (not shown) in the phase modulation elements 54G and 54B, similarly to the phase modulation element 54R. The refractive index of the liquid crystal layer in each dot of 54B is also controlled. The control unit 70 performs these controls based on a signal input to the control unit 70 from the outside. In the present embodiment, the control unit 70 is electrically connected to a control device 71 such as an ECU (electronic control device) of the vehicle.

In the present embodiment, the same phase modulation pattern is formed in each modulation unit in the phase modulation element 54R. Further, the same phase modulation pattern is formed in each modulation unit in the phase modulation element 54G, and the same phase modulation pattern is formed in each modulation unit in the phase modulation element 54B. In the present embodiment, like the phase modulation pattern in the first embodiment, the phase modulation pattern is a pattern of the refractive index of the liquid crystal layer 27 in each dot, and between the electrode 25 and the transparent electrode 28 corresponding to each dot. It can be understood that this is also the pattern of the voltage applied to. By adjusting this phase modulation pattern, the light distribution pattern of the emitted light can be changed to a desired light distribution pattern. In the present embodiment, the phase modulation patterns in the phase modulation elements 54R, 54G, and 54B are different from each other.

Specifically, in this embodiment, the phase modulation patterns in the phase modulation elements 54R, 54G, and 54B are obtained by combining the light DLR, DLG, and DLB emitted from each of the phase modulation elements 54R, 54G, and 54B with the combining optical system 55. 4B is a phase modulation pattern for diffracting the laser beams emitted from the collimating lenses 53R, 53G, and 53B so that the combined light PTN _L shown in FIG. In other words, the phase modulation elements 54R, 54G, and 54B are light distribution patterns PTN _L in which the light DLR, DLG, and DLB emitted from each of the phase modulation elements 54R, 54G, and 54B is synthesized in the synthesis optical system 55. The laser beams emitted from the collimating lenses 53R, 53G, and 53B are diffracted so that This light distribution pattern includes an intensity distribution. Therefore, in the present embodiment, the light DLR emitted from the phase modulation element 54R is a strength distribution based on the intensity distribution of the light distribution pattern PTN _L low beam with overlapping the light distribution pattern PTN _L of the low beam. The light DLG emitted from the phase modulation element 54G overlaps the low beam light distribution pattern PTN _L and has an intensity distribution based on the intensity distribution of the low beam light distribution pattern. Further, the light DLB emitted from the phase modulating element 54B is an intensity distribution based on the intensity distribution of the light distribution pattern PTN _L low beam with overlapping the light distribution pattern PTN _L of the low beam. As described above, each of the phase modulation elements 54R, 54G, and 54B has a plurality of modulation units that form the same phase modulation pattern, and the collimating lens so that each modulation unit has such a light distribution pattern. The laser beams emitted from 53R, 53G, and 53B are diffracted, respectively. The phase modulation elements 54R, 54G, and 54B are configured such that the outer shape of the light distribution pattern of the light DLR, DLG, and DLB emitted from the phase modulation elements 54R, 54G, and 54B matches the outer shape of the low beam light distribution pattern PTN _L. In addition, it is preferable to diffract the laser beams emitted from the collimating lenses 53R, 53G, and 53B, respectively. Thus, the phase modulation element 54R emits the red component light DLR of the low-beam light distribution pattern PTN _L , and the phase modulation element 54G emits the green component light DLG of the low-beam light distribution pattern PTN _L , and the phase modulation element 54B. Emits the light component DLB of the blue component of the light distribution pattern PTN _L of the low beam.

The above and intensity distribution based on the intensity distribution of the light distribution pattern PTN _L of the low beam is in the portion intensity at high light distribution pattern PTN _L of the low beam, the phase modulation element 54R, 54G, light emitted from 54B DLR, This means that the strength of DLG and DLB is also high.

Further, each phase modulation pattern in the phase modulation elements 54R, 54G, and 54B is changed at a time interval shorter than a predetermined time interval. That is, the phase modulation elements 54R, 54G, and 54B diffract the laser beams emitted from the collimating lenses 53R, 53G, and 53B, respectively, with a phase modulation pattern that changes at a time interval shorter than a predetermined time interval. In the present embodiment, the phase modulation patterns in the phase modulation elements 54R, 54G, and 54B are the light DLR, DLG, and DLB emitted from the phase modulation elements 54R, 54G, and 54B at a focal position that is a predetermined distance away from the vehicle. The irradiated area is changed so as to vibrate in a predetermined direction. This focal position is, for example, a position 25 m away from the vehicle. Therefore, the region irradiated with the light DLR emitted from the phase modulation element 54R vibrates in a predetermined direction corresponding to the change of the phase modulation pattern in the phase modulation element 54R, and the light DLG emitted from the phase modulation element 54G The irradiated region vibrates in a predetermined direction corresponding to the change of the phase modulation pattern in the phase modulation element 54G, and the region irradiated with the light DLB emitted from the phase modulation element 54B is the phase modulation in the phase modulation element 54B. It vibrates in a predetermined direction in response to the pattern change. Each phase modulation pattern in the phase modulation elements 54R, 54G, and 54B is preferably changed so as not to change the outer shape of the region corresponding to the vibration of the region irradiated with the light DLR, DLG, and DLB. .

The amplitude of vibration in this region is smaller than the width of this region in the vibration direction. For this reason, it can be understood that the regions irradiated with the light DLR emitted from the phase modulation elements 54R having different phase modulation patterns overlap each other. In addition, it can be understood that regions irradiated with the light DLG emitted from the phase modulation elements 54G having different phase modulation patterns overlap each other. Further, it can be understood that regions irradiated with the light DLB emitted from the phase modulation elements 54B having different phase modulation patterns overlap each other. Note that the amplitude of the vibration in this region is preferably set to such an extent that a person in the vehicle cannot recognize the vibration in this region. For example, when the time intervals at which the phase modulation patterns in the phase modulation elements 54R, 54G, and 54B change are set to 1/15 s or less, the above-described amplitude at the focal position 25 m away from the vehicle is 3.6 mm or less. It is preferable.

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

First, when power is supplied from a power source (not shown), laser beams are emitted from the light sources 52R, 52G, and 52B, respectively. As described above, red laser light is emitted from the first light source 52R, green laser light is emitted from the second light source 52G, and blue laser light is emitted from the third light source 52B. The respective laser beams are collimated by the collimating lenses 53R, 53G, and 53B, and then enter the phase modulation elements 54R, 54G, and 54B. The phase modulation elements 54R, 54G, and 54B diffract the laser light incident on the phase modulation elements 54R, 54G, and 54B, respectively. The first light DLR, which is the red component light of the low beam light distribution pattern PTN _L , is emitted from the phase modulation element 54R, and the first light DLR, which is the green component light of the low beam light distribution pattern PTN _L , is emitted from the phase modulation element 54G. The second light DLG is emitted, and the third light DLB, which is the light of the blue component of the low beam distribution pattern PTN _L , is emitted from the phase modulation element 54B. Thus, the first light DLR is emitted from the first light emitting optical system 51R, the second light DLG is emitted from the second light emitting optical system 51G, and the third light DLB is emitted from the third light emitting optical system 51B.

In the combining optical system 55, first, the first light DLR and the second light DLG are combined by the first optical element 55f. The first light DLR and the second light DLG combined by the first optical element 55f are combined with the third light DLB by the second optical element 55s. In this way, the light obtained by combining the first red light DLR, the second green light DLG, and the third blue light DLB becomes white light. Further, the first light DLR, the second light DLG, and the third light DLB overlap with the low beam light distribution pattern PTN _L as described above, and are based on the intensity distribution of the low beam light distribution pattern PTN _L. Since the intensity distribution is obtained, white light obtained by combining these lights has a low beam intensity distribution.

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

Incidentally, as described above, the respective phase modulation patterns in the phase modulation elements 54R, 54G, and 54B are changed at a time interval shorter than a predetermined time interval. These changes in the phase modulation pattern are such that the region irradiated with the light DLR, DLG, DLB emitted from the phase modulation elements 54R, 54G, 54B vibrates in a predetermined direction at a focal position away from the vehicle by a predetermined distance. It has been changed. Therefore, each of the regions irradiated with the light DLR, DLG, DLB emitted from the phase modulation elements 54R, 54G, 54B has a predetermined direction corresponding to the change of the phase modulation pattern in the phase modulation elements 54R, 54G, 54B. Vibrate. In addition, regions irradiated with the light DLR emitted from the phase modulation elements 54R having different phase modulation patterns overlap each other. For this reason, in the portion of the irradiated object such as the road surface where these regions overlap each other, the visually continuous light DLR is superposed, and the optical path from the phase modulation element 54R to this portion is It changes corresponding to the change of the phase modulation pattern in the phase modulation element 54R. In addition, regions irradiated with the light DLG emitted from the phase modulation elements 54G having different phase modulation patterns are overlapped with each other. For this reason, in the part where these regions overlap each other in the irradiated object such as the road surface, the visually continuous light DLG is superposed, and the optical path from the phase modulation element 54G to this part is It changes corresponding to the change of the phase modulation pattern in the phase modulation element 54G. In addition, regions irradiated with the light DLB emitted from the phase modulation elements 54B having different phase modulation patterns overlap each other. For this reason, in the part where these regions overlap each other in the irradiated object such as the road surface, the visually continuous light DLB is superimposed, and the optical path from the phase modulation element 54B to this part is It changes corresponding to the change of the phase modulation pattern in the phase modulation element 54B. When the optical path changes in this way, the first light DLR, the second light DLG, and the third light that enter the irradiated object from the vehicle headlamp 1 even at the same position of the irradiated object such as the road surface. The incident angle of the light DLB and the phase of the light can change. Therefore, the visual superimposition of the first light DLR having different incident angles and phases, the visual superimposition of the second light DLG having different incident angles and phases, and the third light having different incident angles and phases. Each of the DLB visual overlays occurs continuously. For this reason, it can suppress feeling each flicker of 1st light DLR, 2nd light DLG, and 3rd light DLB. In this way, it is possible to suppress the feeling of flickering of the low beam formed by the first light DLR, the second light DLG, and the third light DLB.

It should be noted that the time intervals at which the phase modulation patterns in the phase modulation elements 54R, 54G, and 54B change are preferably 1/15 s or less from the viewpoint of suppressing light flickering. The human visual temporal resolution is approximately 1/30 s. In the case of a vehicular lamp, it is possible to suppress the flickering of light if the visual light overlapping time interval is about twice this time. If this time interval is 1/30 s or less, the time resolution of human vision is generally exceeded. Therefore, it is possible to further suppress the feeling of light flicker. Further, from the viewpoint of further suppressing the feeling of flickering of light, this time interval is preferably 1/60 s or less.

The direction in which the region irradiated with the light DLR, DLG, DLB emitted from the phase modulation elements 54R, 54G, 54B oscillates in response to changes in the respective phase modulation patterns in the phase modulation elements 54R, 54G, 54B. There is no particular limitation. For example, the vibration direction may be the up-down direction, the left-right direction, the up-down direction, and the left-right direction. However, from the viewpoint of suppressing the feeling of flickering of light, the direction is preferably set to two or more directions. Compared to the case where the direction of vibration is two or more directions, the visual continuous superposition of light occurs in multiple directions, and the light flickers. Can be further suppressed. Further, the vibration direction of the region irradiated with the light DLR, the vibration direction of the region irradiated with the light DLG, and the vibration direction of the region irradiated with the light DLB may be the same direction or different directions. Also good. Moreover, although each amplitude in the vibration of the area | region irradiated with light DLR, DLG, and DLB may be substantially constant, it is preferable to fluctuate from a viewpoint of suppressing feeling of light flicker. By changing the amplitude, it is possible to further suppress the occurrence of visually flickering by visually overlapping light continuously in multiple directions as compared with the case where the amplitude does not change. In addition, the amplitude in the vibration of the region irradiated with the light DLR, DLG, DLB may be different from each other, or may be the same amplitude. These vibrations may be synchronized with each other or may be asynchronous.

By the way, as the light incident on the hologram element of the vehicle headlamp of Patent Document 1, for example, laser light is cited. However, when the subject is irradiated with laser light, the fine spot pattern that causes light flickering due to the light scattered on the irradiated surface interfering with each other due to the influence of minute irregularities on the irradiated surface. There is a concern that speckle will occur.

Accordingly, the vehicle headlamp 1 of the present embodiment as the second aspect includes light sources 52R, 52G, and 52B that emit light of predetermined wavelengths, respectively, and three phase modulation elements 54R, 54G, and 54B. . The phase modulation element 54R diffracts and emits the light emitted from the first light source 52R with a phase modulation pattern that changes at a time interval shorter than a predetermined time interval. The phase modulation element 54G diffracts and emits the light emitted from the second light source 52G with a phase modulation pattern that changes at a time interval shorter than a predetermined time interval. The phase modulation element 54B diffracts and emits the light emitted from the third light source 52B with a phase modulation pattern that changes at a time interval shorter than a predetermined time interval. The region irradiated with the light DLR emitted from the phase modulation element 54R vibrates in a predetermined direction corresponding to the change of the phase modulation pattern in the phase modulation element 54R, and is emitted from the phase modulation elements 54R having different phase modulation patterns. Regions irradiated with the light DLR overlap each other. For this reason, as described above, in the portion of the irradiated object such as the road surface where these regions overlap each other, visually continuous superimposing of the light DLR occurs, and the phase modulation element 54R reaches this portion. Until the optical path changes corresponding to the change of the phase modulation pattern in the phase modulation element 54R. The region irradiated with the light DLG emitted from the phase modulation element 54G vibrates in a predetermined direction corresponding to the change of the phase modulation pattern in the phase modulation element 54G, and from the phase modulation elements 54G having different phase modulation patterns. The areas irradiated with the emitted light DLG overlap each other. For this reason, as described above, in the portion of the irradiated object such as the road surface where these regions overlap each other, visually continuous superimposing of the light DLG occurs, and the phase modulation element 54G reaches this portion. Until the optical path changes corresponding to the change of the phase modulation pattern in the phase modulation element 54G. Further, the region irradiated with the light DLB emitted from the phase modulation element 54B vibrates in a predetermined direction corresponding to the change of the phase modulation pattern in the phase modulation element 54B, and from the phase modulation elements 54B having different phase modulation patterns. The areas irradiated with the emitted light DLB overlap each other. For this reason, as described above, in the portion of the irradiated object such as the road surface where these regions overlap each other, visually continuous superimposing of the light DLB occurs, and this portion is reached from the phase modulation element 54B. Until the optical path changes corresponding to the change of the phase modulation pattern in the phase modulation element 54B.

When the optical path length changes in this way, as described above, the first light DLR that forms the low beam incident on the irradiated object from the vehicle headlamp 1 even at the same position of the irradiated object such as the road surface. The incident angles of the second light DLG and the third light DLB and the phase of these lights can be changed. Therefore, the visual superimposition of the first light DLR having different incident angles and phases, the visual superimposition of the second light DLG having different incident angles and phases, and the third light having different incident angles and phases. Each of the DLB visual overlays occurs continuously. For this reason, it can be suppressed that the flickering of the low beam formed by the first light DLR, the second light DLG, and the third light DLB is felt.

Further, in the present embodiment as the second aspect, since there are three light sources that emit light of different wavelengths and three light-emitting optical systems respectively corresponding to the three light sources, the light is emitted from each light source. By adjusting the light intensity, light of a desired color can be emitted.

(Fourth embodiment)
Next, a fourth embodiment as the second aspect of the present invention will be described in detail with reference to FIG. FIG. 10 is a view showing the optical system unit in the fourth embodiment as the second mode of the present invention in the same manner as FIG. In addition, about the component which is the same as that of 3rd Embodiment, or equivalent, except the case where it demonstrates especially, the same referential mark is attached | subjected and the overlapping description is abbreviate | omitted.

As shown in FIG. 10, the optical system unit 50 of the present embodiment is a transmission type phase modulation element that mainly diffracts and emits light incident on each of the phase modulation elements 54R, 54G, and 54B. This is different from the optical system unit 50 of the first embodiment.

In the present embodiment, the phase modulation elements 54R, 54G, and 54B are LCDs that are transmissive liquid crystal panels, for example, similarly to the phase modulation element 22 of the second embodiment shown in FIG. Red laser light emitted from the first collimating lens 53R is incident on the phase modulation element 54R, and the phase modulation element 54R diffracts and emits the red laser light. Green laser light emitted from the second collimating lens 53G is incident on the phase modulation element 54G, and the phase modulation element 54G diffracts and emits the green laser light. Red laser light emitted from the third collimating lens 53B is incident on the phase modulation element 54B, and the phase modulation element 54B diffracts and emits the blue laser light.

Each of the phase modulation elements 54R, 54G, and 54B of the present embodiment diffracts incident light by adjusting the refractive index of the liquid crystal layer 27 in each dot, similarly to the phase modulation element 22 of the second embodiment. The light distribution pattern of the emitted light can be changed to a desired light distribution pattern. Further, each of the phase modulation elements 54R, 54G, and 54B of the present embodiment changes the light distribution pattern of the emitted light by changing the refractive index of the liquid crystal layer 27 in each dot, and the direction of the emitted light. It is possible to change the area irradiated with this light by changing. Each of the phase modulation elements 54R, 54G, and 54B emits light from the other translucent substrate 29 when light enters from the one translucent substrate 23a side. Even in this case, each of the phase modulation elements 54R, 54G, and 54B can adjust the refractive index of the liquid crystal layer 27 in each dot to change the light distribution pattern of the emitted light to a desired light distribution pattern. Even in this case, each of the phase modulation elements 54R, 54G, 54B changes the light distribution pattern of the emitted light or emits it by changing the refractive index of the liquid crystal layer 27 in each dot. It is possible to change the area irradiated with this light by changing the direction of the light.

In the present embodiment, similarly to the third embodiment, the same phase modulation pattern is formed in each modulation unit in the phase modulation element 54R. Further, the same phase modulation pattern is formed in each modulation unit in the phase modulation element 54G, and the same phase modulation pattern is formed in each modulation unit in the phase modulation element 54B. The phase modulation patterns in the phase modulation elements 54R, 54G, and 54B are different from each other.

Specifically, also in the present embodiment, similarly to the third embodiment, the phase modulation elements 54R, 54G, and 54B combine the light DLR, DLG, and DLB emitted from the phase modulation elements 54R, 54G, and 54B, respectively. The laser beams emitted from the collimating lenses 53R, 53G, and 53B are diffracted so that the emitted light becomes a low beam light distribution pattern PTN _L. Therefore, the first light DLR that is the red component light of the low beam light distribution pattern PTN _L is emitted from the phase modulation element 54R, and the green component light of the low beam light distribution pattern PTN _L is emitted from the phase modulation element 54G. The second light DLG is emitted, and the third light DLB, which is the blue component light of the low beam light distribution pattern PTN _L , is emitted from the phase modulation element 54B. Then, the first light DLR, the second light DLG, and the third light DLB are combined by the combining optical system 55. As in the third embodiment, the first light DLR, the second light DLG, and the third light DLB overlap with the low beam light distribution pattern PTN _{L and have} the intensity distribution of the low beam light distribution pattern PTN _L , respectively. Since the intensity distribution is based on the white light, the white light obtained by combining these lights has a low beam intensity distribution. The phase modulation elements 54R, 54G, and 54B are configured such that the outer shape of the light distribution pattern of the light DLR, DLG, and DLB emitted from the phase modulation elements 54R, 54G, and 54B matches the outer shape of the low beam light distribution pattern PTN _L. In addition, it is preferable to diffract the laser beams emitted from the collimating lenses 53R, 53G, and 53B, respectively. The combined white light is emitted from the opening 59H of the cover 59, and this light is emitted from the vehicle headlamp 1 via the front cover 12. Since this light has a low beam distribution pattern PTN _L , the irradiated light is a low beam.

Also in this embodiment, as in the third embodiment, the phase modulation pattern in the phase modulation element 54R changes at a time interval shorter than a predetermined time interval, and the light DLR emitted from the phase modulation element 54R is irradiated. The region to be vibrated in a predetermined direction corresponding to the change of the phase modulation pattern in the phase modulation element 54R. Thus, the regions irradiated with the light DLR emitted from the phase modulation elements 54R having different phase modulation patterns overlap each other. The phase modulation pattern in the phase modulation element 54G changes at a time interval shorter than a predetermined time interval, and the region irradiated with the light DLG emitted from the phase modulation element 54G is the phase modulation pattern in the phase modulation element 54G. It vibrates in a predetermined direction in response to the change. Thus, the regions irradiated with the light DLG emitted from the phase modulation elements 54G having different phase modulation patterns overlap each other. The phase modulation pattern in the phase modulation element 54B changes at a time interval shorter than the predetermined time interval, and the region irradiated with the light DLB emitted from the phase modulation element 54B is the phase modulation pattern in the phase modulation element 54B. It vibrates in a predetermined direction in response to the change. Thus, the regions irradiated with the light DLB emitted from the phase modulation elements 54B having different phase modulation patterns overlap each other.

According to the vehicle headlamp 1 of the present embodiment, the first light DLR, the second light DLG, and the third light DLR, as in the vehicle headlamp 1 of the third embodiment as the second aspect. It is possible to suppress the flickering of the low beam formed by the light DLB.

(Fifth embodiment)
Next, a fifth embodiment as the second aspect of the present invention will be described in detail with reference to FIG. In addition, about the component which is the same as that of 4th Embodiment, or equivalent, except the case where it demonstrates especially, the same referential mark is attached | subjected and the overlapping description is abbreviate | omitted.

FIG. 11 is a view showing the optical system unit in the fifth embodiment as the second aspect of the present invention in the same manner as FIG. As shown in FIG. 11, the optical system unit 50 of this embodiment does not include the combining optical system 55, and each light emitted from the first light emitting optical system 51R, the second light emitting optical system 51G, and the third light emitting optical system 51B. Is different from the optical system unit 50 according to the fourth embodiment in that light is emitted from the cover 59 in a state where are not combined. In the present embodiment, in the first light emitting optical system 51R, the second light emitting optical system 51G, and the third light emitting optical system 51B, the light emission direction is set to the opening 59H side of the cover 59.

Also in the present embodiment, similarly to the fourth embodiment, the phase modulation elements 54R, 54G, and 54B receive light obtained by combining the light DLR, DLG, and DLB emitted from the phase modulation elements 54R, 54G, and 54B, respectively. The laser beams emitted from the collimating lenses 53R, 53G, and 53B are diffracted so that the low beam distribution pattern PTN _L is obtained. Therefore, the first light DLR that is the red component light of the low beam light distribution pattern PTN _L is emitted from the phase modulation element 54R, and the green component light of the low beam light distribution pattern PTN _L is emitted from the phase modulation element 54G. The second light DLG is emitted, and the third light DLB, which is the blue component light of the low beam light distribution pattern PTN _L , is emitted from the phase modulation element 54B. The first light DLR emitted from the phase modulation element 54R, the second light DLG emitted from the phase modulation element 54R, and the third light DLB emitted from the phase modulation element 54B are emitted from the opening 59H of the cover 59, respectively. The light is irradiated to the outside of the vehicle headlamp 1 through the front cover 12. At this time, the first light DLR, the second light DLG, and the third light DLB are irradiated so that the areas irradiated with the respective lights overlap each other at a focal position separated from the vehicle by a predetermined distance. . This focal position is, for example, a position 25 m away from the vehicle. The first light DLR, the second light DLG, and the third light DLB are preferably irradiated so that the outer shapes of the respective light distribution patterns substantially coincide at this focal position.

Also in the present embodiment, similarly to the fourth embodiment, the phase modulation pattern in the phase modulation element 54R changes at a time interval shorter than a predetermined time interval, and the light DLR emitted from the phase modulation element 54R changes. The irradiated region vibrates in a predetermined direction corresponding to the change of the phase modulation pattern in the phase modulation element 54R. Thus, the regions irradiated with the light DLR emitted from the phase modulation elements 54R having different phase modulation patterns overlap each other. The phase modulation pattern in the phase modulation element 54G changes at a time interval shorter than a predetermined time interval, and the region irradiated with the light DLG emitted from the phase modulation element 54G is the phase modulation pattern in the phase modulation element 54G. It vibrates in a predetermined direction in response to the change. Thus, the regions irradiated with the light DLG emitted from the phase modulation elements 54G having different phase modulation patterns overlap each other. The phase modulation pattern in the phase modulation element 54B changes at a time interval shorter than the predetermined time interval, and the region irradiated with the light DLB emitted from the phase modulation element 54B is the phase modulation pattern in the phase modulation element 54B. It vibrates in a predetermined direction in response to the change. Thus, the regions irradiated with the light DLB emitted from the phase modulation elements 54B having different phase modulation patterns overlap each other.

According to the vehicle headlamp 1 of the present embodiment, since the combining optical system 55 of the third embodiment as the second aspect is not used, the configuration can be simplified, and the first light DLR and It is possible to suppress the flickering of the low beam formed by the second light DLG and the third light DLB.

In the third to fifth embodiments as the second mode, the vehicular headlamp 1 as the vehicular lamp is assumed to irradiate a low beam. However, the vehicular headlamp 1 as the second mode of the present invention The lamp is not particularly limited. For example, the vehicular lamp as the second aspect may be irradiated with a high beam, or may be irradiated with light constituting an image. If the vehicle lamp is intended to irradiate a high beam, the light of the high beam light distribution pattern PTN _H is a light distribution pattern for night lighting, shown in FIG. 4 (B) is irradiated. That is, each of the phase modulation elements diffracts the light so that the combined light forms a light distribution pattern including a high beam intensity distribution. Further, when the vehicle lamp emits light constituting the image, the direction of the light emitted from the vehicle lamp and the position where the vehicle lamp is attached to the vehicle are not particularly limited.

In the third to fifth embodiments as the second mode, three light sources 52R, 52G, and 52B that emit light having different wavelengths and three phase modulations corresponding to the respective light sources 52R, 52G, and 52B are used. The optical system unit 50 including the elements 54R, 54G, and 54B has been described as an example. However, the optical system unit as the second aspect may include at least one light source and a phase modulation element corresponding to the light source. For example, the optical system unit may include a light source that emits white light and a phase modulation element that diffracts and emits the white light emitted from the light source.

In the third to fifth embodiments as the second mode, the phase modulation patterns in the phase modulation elements 54R, 54G, and 54B are the phase modulation elements 54R and 54G at the focal position that is a predetermined distance away from the vehicle. , 54B, the region irradiated with the light DLR, DLG, DLB is changed so as to vibrate in a predetermined direction. For this reason, each of the regions irradiated with the light DLR, DLG, DLB emitted from the phase modulation elements 54R, 54G, 54B is predetermined in response to the change in the phase modulation pattern in each of the phase modulation elements 54R, 54G, 54B. It was vibrating in the direction of. However, the phase modulation element as the second aspect diffracts and emits the light emitted from the light source with a phase modulation pattern that changes at a time interval shorter than a predetermined time interval, and the phase modulation elements having different phase modulation patterns It suffices that the areas irradiated with the light emitted from each other overlap each other. With such a configuration, at least one of the light distribution pattern of the light emitted from the phase modulation element and the region irradiated with the light can change corresponding to the change of the phase modulation pattern. In addition, since the areas irradiated with the light emitted from the phase modulation elements having different phase modulation patterns overlap with each other, the overlapping of visually continuous light is performed in the portion of the irradiated object where these areas overlap each other. The optical path from the phase modulation element to this part changes corresponding to the change of the phase modulation pattern. When the optical path changes in this way, even at the same position of the irradiated object, the incident angle and the phase of the light incident on the irradiated object from the vehicular lamp can be changed. Accordingly, it is possible to suppress the visual superimposition of light having different angles of incidence and phases and to prevent the light from flickering.

Further, the phase modulation pattern in the phase modulation element as the second aspect may be changed so that the intensity distribution in the light distribution pattern of the light emitted from the phase modulation element changes. That is, the intensity distribution in the light distribution pattern of the light emitted from the phase modulation element may change corresponding to the change in the phase modulation pattern in the phase modulation element. Even with such a configuration, it is possible to suppress the visual superimposition of light having different incident angles and phases, and to prevent the light from flickering. In addition, it is preferable that the change in the intensity distribution is a change that does not allow a person in the vehicle to recognize the change in the intensity distribution. For example, when the time interval at which the phase modulation pattern in the phase modulation element changes is 1/15 s or less, the intensity change rate is preferably 5% or less. When the intensity distribution in the light distribution pattern of the light emitted from the phase modulation element changes in this way, the phase modulation pattern may change so that the outer shape of the light distribution pattern corresponds to the change in the intensity distribution. . However, the phase modulation pattern is preferably changed so that the outer shape of the light distribution pattern does not change in response to the change in the intensity distribution in the light distribution pattern. That is, it is preferable that only the intensity distribution in the light distribution pattern of the light emitted from the phase modulation element changes. Further, the phase modulation pattern in the phase modulation element changes the intensity distribution of the light distribution pattern of the light emitted from the phase modulation element in response to the change in the phase modulation pattern, and is irradiated with the light emitted from the phase modulation element. The area to be applied may be changed so as to vibrate in a predetermined direction. That is, the intensity distribution in the light distribution pattern of the light emitted from the phase modulation element changes corresponding to the change of the phase modulation pattern in the phase modulation element, and the region irradiated with the light emitted from the phase modulation element is predetermined. You may vibrate in the direction of. Further, in response to the change of the phase modulation pattern in the phase modulation element, the intensity distribution in the light distribution pattern of the light emitted from the phase modulation element changes, and the region irradiated with the light emitted from the phase modulation element also changes. You don't have to.

In the third to fifth embodiments as the second mode, the phase modulation elements 54R, 54G, and 54B having a plurality of modulation units have been described as examples. However, the number, size, outer shape and the like of the modulation unit are not particularly limited. For example, the phase modulation element may have one modulation unit, and incident light may be diffracted by this one modulation unit.

In the third embodiment as the second aspect, the reflection type phase modulation elements 54R, 54G, and 54B will be described as an example. In the fourth and fifth embodiments as the second aspect, the transmission type is used. The phase modulation elements 54R, 54G, and 54B have been described as examples. However, the phase modulation element only needs to be able to change the light distribution pattern of the emitted light while diffracting and emitting the incident light. For example, the phase modulation element may be a GLV in which a plurality of reflectors are formed on a silicon substrate.

In the third to fifth embodiments as the second mode, the phase modulation patterns in the phase modulation elements 54R, 54G, and 54B are different from each other, but these phase modulation patterns are the same. It may be a phase modulation pattern.

In the third embodiment and the fourth embodiment as the second mode, the first optical element 55f transmits the first light DLR and reflects the second light DLG, whereby the first light DLR is transmitted. And the second light DLG, and the second optical element 55s transmits the first light DLR and the second light DLG synthesized by the first optical element 55f and reflects the third light DLB. Thus, the first light DLR, the second light DLG, and the third light DLB were synthesized. However, for example, the third light DLB and the second light DLG are combined by the first optical element 55f, and the third light DLB and the second light DLB combined by the first optical element 55f are combined by the second optical element 55s. The optical DLG and the first optical DLR may be combined. In this case, in the third embodiment and the fourth embodiment as the second mode, the first light emitting optical system 51R including the first light source 52R, the first collimating lens 53R, and the phase modulation element 54R, and the third light source 52B. The positions of the third light emitting optical system 51B including the third collimating lens 53B and the phase modulation element 54B are switched. In the third embodiment and the fourth embodiment as the second mode, the band pass filter that transmits light in a predetermined wavelength band and reflects light in other wavelength bands is the first optical element 55f or the second optical filter. It may be used for the optical element 55s. The combining optical system 55 only needs to superimpose the light emitted from the respective light emitting optical systems, and is not limited to the configurations of the third and fourth embodiments as the second mode or the above configuration.

(Sixth embodiment)
Next, a sixth embodiment as the third aspect of the present invention will be described. Note that the same or equivalent components as those in the third embodiment are denoted by the same reference numerals, unless otherwise described, and redundant description is omitted. FIG. 12 is a view showing an example of the vehicle lamp according to the present embodiment as the third mode, and is a longitudinal sectional view schematically showing a vertical section of the vehicle lamp. Similarly to the third embodiment, the vehicle lamp is the vehicle headlamp 1 in the present embodiment. As shown in FIG. 12, the vehicle headlamp 1 of the present embodiment is different from that of the third embodiment in that the cover 59 is a case 40 and the configuration of the optical system unit 50 is different. Mainly different from 1.

The case 40 of the present embodiment includes a base 41 made of a metal such as aluminum and a cover 42, and the base 41 is fixed to the upper surface of the base plate 31 in the heat sink 30. An opening is formed in the base 41 from the front to the top. The cover 42 is fixed to the base 41 so as to close the opening on the upper side. In the front portion of the case 40, an opening 40H defined by the front end portion of the base 41 and the front end portion of the cover 42 is formed. An optical system unit 50 is disposed in the internal space of the case 40.

In addition, in order to give light absorption to the inner wall of the base 41 and the inner wall of the cover 42, it is preferable to perform black alumite processing or the like on these inner walls. Since the inner wall of the base 41 and the inner wall of the cover 42 have light absorptivity, even when light is irradiated to these inner walls due to unintentional reflection or refraction, the irradiated light is reflected and passes through the opening 40H. Emitting in an unintended direction can be suppressed.

FIG. 13 is an enlarged view of the optical system unit 50 provided in the vehicle headlamp 1 shown in FIG. As shown in FIG. 13, the optical system unit 50 in this embodiment includes a first light source 52R, a second light source 52G, a third light source 52B, a first collimator lens 53R, a second collimator lens 53G, A third collimating lens 53B, a first diffraction grating 154R, a second diffraction grating 154G, a third diffraction grating 154B, a first MEMS (Micro Electro Mechanical System) mirror 80R, a second MEMS mirror 80G, and a third MEMS mirror 80B; And a synthetic optical system 55. In the present embodiment, the diffraction gratings 154R, 154G, and 154B are transmissive diffraction gratings.

In the present embodiment, the first light source 52R emits red laser light having a power peak wavelength of, for example, 638 nm upward. In the present embodiment, the second light source 52G emits green laser light having a power peak wavelength of, for example, 515 nm backward, and the third light source 52B emits blue laser light having a power peak wavelength of, for example, 445 nm backward. Further, the optical system unit 50 has a circuit board (not shown) fixed to the base 41. The first light source 52R, the second light source 52G, and the third light source 52B are each mounted on the circuit board, and power is supplied to these light sources via the circuit board.

In the present embodiment, the first collimating lens 53R is disposed above the first light source 52R, and collimates the fast axis direction and the slow axis direction of the laser light emitted from the first light source 52R. The second collimating lens 53G is disposed behind the second light source 52G, and collimates the fast axis direction and the slow axis direction of the laser light emitted from the second light source 52G. The third collimating lens 53B is disposed behind the third light source 52B, and collimates the fast axis direction and the slow axis direction of the laser light emitted from the third light source 52B. These collimating lenses 53R, 53G, and 53B are fixed to the base 41 by a configuration (not shown).

The first MEMS mirror 80R is disposed above the first collimating lens 53R. The first MEMS mirror 80R is attached to the base 41 with a configuration (not shown), and the movable reflecting surface 81R is slid by an actuator (not shown). The movable reflecting surface 81R is disposed at a position where at least a part of the laser light emitted from the first collimating lens 53R can enter and in a state inclined by approximately 45 ° with respect to the optical axis of the laser light.

The second MEMS mirror 80G is disposed behind the second collimating lens 53G. The second MEMS mirror 80G is attached to the base 41 with a configuration (not shown), and the movable reflecting surface 81G is slid by an actuator (not shown). The movable reflecting surface 81G is disposed at a position where at least a part of the laser light emitted from the second collimating lens 53G can enter, in a state inclined by approximately 45 ° with respect to the optical axis of the laser light.

The third MEMS mirror 80B is disposed behind the third collimating lens 53B. The third MEMS mirror 80B is attached to the base 41 with a configuration (not shown), and the movable reflecting surface 81B is slid by an actuator (not shown). The movable reflecting surface 81B is disposed at a position where at least a part of the laser light emitted from the third collimating lens 53B can enter, in a state inclined by approximately 45 ° with respect to the optical axis of the laser light.

FIG. 14 is a schematic view of an example of the first MEMS mirror 80R viewed from the movable reflecting surface 81R side. As shown in FIG. 14, the first MEMS mirror 80R includes a mirror main body 60 in which a movable reflecting surface 81R is formed, an inner frame portion 61 that surrounds the mirror main body 60, and an outer frame portion 62 that surrounds the inner frame portion 61. It is provided as a main component. The mirror main body 60 and the inner frame portion 61 are connected by a pair of torsion bars 63 and 63 extending along the first axis P. Further, the inner frame portion 61 and the outer frame portion 62 are connected by a pair of second torsion bars 64 and 64 extending along a second axis Q perpendicular to the first axis P. With such a configuration, the mirror main body 60 can swing in two directions around the first axis P and the second axis Q by operating the actuator. As the actuator, for example, an electromagnetic actuator or a piezoelectric actuator may be used. In the present embodiment, the second MEMS mirror 80G and the third MEMS mirror 80B have the same configuration as the first MEMS mirror 80R.

Note that the MEMS mirror may be configured to swing only in one direction, for example, along the first axis P. In this case, the outer frame portion 62 and the second torsion bar 64 are not necessary, and the MEMS mirror can be reduced in size.

As shown in FIG. 13, the first diffraction grating 154R is arranged in front of the first MEMS mirror 80R, the second diffraction grating 154G is arranged above the second MEMS mirror 80G, and the third diffraction grating 154B. Is disposed above the third MEMS mirror 80B.

FIG. 15 is a schematic view of the diffraction grating 154R in the present embodiment as viewed from the incident surface side. As shown in FIG. 15, the diffraction grating 154R is configured as an aggregate of diffraction grating patterns 170 formed in each of the divided regions. Each of these diffraction grating patterns 170 has the same three-dimensional structure (not shown). Therefore, the light of the same light distribution pattern is emitted from each of the laser light incident on each diffraction grating pattern 170. In the present embodiment, the diffraction gratings 154G and 154B have the same configuration as the diffraction grating 154R.

Further, as shown in FIG. 13, the synthesis optical system 55 includes a first optical element 55f and a second optical element 55s, similarly to the synthesis optical system 55 of the third embodiment. In the present embodiment, the first optical element 55f is disposed in front of the first diffraction grating 154R and above the second diffraction grating 154G, and is disposed in a state inclined by approximately 45 ° with respect to both the front-rear direction and the vertical direction. The In the present embodiment, the first optical element 55f is configured to transmit red laser light having a wavelength of 638 nm emitted from the first light source 52R and reflect green laser light having a wavelength of 515 nm emitted from the second light source 52G. .

In the present embodiment, the second optical element 55s is disposed in front of the first optical element 55f and above the third diffraction grating 154B, and is disposed at an angle of approximately 45 ° with respect to both the front-rear direction and the vertical direction. The In the present embodiment, the second optical element 55s transmits the red laser light having a wavelength of 638 nm emitted from the first light source 52R and the green laser light having a wavelength of 515 nm emitted from the second light source 52G, and emits the light from the third light source 52B. It is configured to reflect blue laser light having a wavelength of 445 nm.

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

As shown in FIG. 13, when power is supplied from a power source (not shown), red laser light is emitted upward from the light source 52R, green laser light is emitted backward from the light source 52G, and blue laser light is emitted from the light source 52B. Is emitted backward.

Above the light source 52R, the movable reflecting surface 81R of the MEMS mirror 80R is disposed in a state inclined by approximately 45 ° with respect to the optical axis of the red laser light emitted from the light source 52R. Therefore, the red laser light is reflected by the movable reflecting surface 81R, changed in direction by 90 °, and propagated forward, that is, toward the diffraction grating 154R. By the way, as described above, the movable reflecting surface 81R swings in two directions. Therefore, as shown in FIG. 16, the red laser light emitted from the movable reflecting surface 81R propagates while vibrating in two directions as the movable reflecting surface 81R swings. FIG. 16 is an enlarged view showing the vicinity of the MEMS mirror 80R and the diffraction grating 154R in FIG.

As shown in FIG. 13, behind the light source 52G, a movable reflecting surface 81G of the MEMS mirror 80G is arranged in a state inclined at approximately 45 ° with respect to the optical axis of the green laser light emitted from the light source 52G. Therefore, the green laser light is reflected by the movable reflecting surface 81G, turned 90 °, and propagates upward, that is, toward the diffraction grating 154G. As described above, since the movable reflecting surface 81G swings in two directions, the green laser light emitted from the movable reflecting surface 81G propagates while oscillating in two directions (see FIG. 16).

The movable reflecting surface 81B of the MEMS mirror 80B is disposed behind the light source 52B in a state inclined approximately 45 ° with respect to the optical axis of the blue laser light emitted from the light source 52B. Therefore, the blue laser light is reflected by the movable reflecting surface 81B, changed in direction by 90 °, and propagates upward, that is, toward the diffraction grating 154B. As described above, since the movable reflecting surface 81B swings in two directions, the blue laser light emitted from the movable reflecting surface 81B propagates while oscillating in two directions (see FIG. 16).

As described above, the MEMS mirrors 80R, 80G, and 80B in the present embodiment have the movable reflection surfaces 81R, 81G, and 81B that reflect the laser light toward the diffraction gratings 154R, 154G, and 154B, and the movable reflection is performed. It functions as a movable reflecting member that vibrates laser light by moving the surfaces 81R, 81G, and 81B.

As shown in FIG. 13, a diffraction grating 154R is arranged in front of the MEMS mirror 80R. Therefore, the red laser light emitted from the MEMS mirror 80R is incident on the incident surface of the diffraction grating 154R. As shown in FIG. 15, the diffraction grating 154R is an aggregate of a plurality of diffraction grating patterns 170 having the same three-dimensional structure. That is, red component light having the same light distribution pattern is generated from each of the red laser light incident on each diffraction grating pattern 170. In the present embodiment, the region irradiated with the red component light always includes at least one diffraction grating pattern 170. For this reason, even when the region where the laser beam is incident on the diffraction grating 154R changes as the MEMS mirror 80R is moved, the red component light having the same light distribution pattern can be generated. Hereinafter, the red component light emitted from the diffraction grating 154G is referred to as a first light LRA. The first light LRA is emitted from the diffraction grating 154G and propagates forward.

A diffraction grating 154G is disposed above the MEMS mirror 80G. Therefore, the green laser light emitted from the MEMS mirror 80G is incident on the incident surface of the diffraction grating 154G. As described above, the diffraction grating 154G is an aggregate of a plurality of diffraction grating patterns 170 having the same three-dimensional structure, like the diffraction grating 154R (see FIG. 15). That is, green component light having the same light distribution pattern is generated from each of the green laser light incident on each diffraction grating pattern 170. In the present embodiment, at least one diffraction grating pattern 170 is always included in the region irradiated with the green component light. For this reason, even when the region where the laser beam is incident on the diffraction grating 154G changes as the MEMS mirror 80G moves, green component light having the same light distribution pattern can be generated. Hereinafter, the green component light emitted from the diffraction grating 154G is referred to as a second light LGA. The second light LGA is emitted from the diffraction grating 154G and propagates upward.

A diffraction grating 154B is disposed above the MEMS mirror 80B. Therefore, the blue laser light emitted from the MEMS mirror 80B is incident on the incident surface of the diffraction grating 154B. As described above, the diffraction grating 154B is an aggregate of a plurality of diffraction grating patterns 170 having the same three-dimensional structure, like the diffraction grating 154R (see FIG. 15). That is, blue component light having the same light distribution pattern is generated from each of the blue laser light incident on each diffraction grating pattern 170. In the present embodiment, at least one diffraction grating pattern 170 is always included in the region irradiated with the blue component light. For this reason, even when the region where the laser beam is incident on the diffraction grating 154G changes as the MEMS mirror 80B is moved, light of a blue component having the same light distribution pattern can be generated. Hereinafter, the blue component light emitted from the diffraction grating 154B is referred to as a third light LBA. The third light LBA is emitted from the diffraction grating 154B and propagates upward.

As described above, the diffraction gratings 154R, 154G, and 154B in the present embodiment function as light distribution pattern forming elements in order to form a predetermined light distribution pattern. In the present embodiment, the diffraction gratings 154R, 154G, and 154B are the light distribution pattern formed from the diffraction grating 154R, the light distribution pattern formed from the diffraction grating 154G, and the light distribution pattern formed from the diffraction grating 154B. Are configured to have the same shape and light intensity distribution.

As shown in FIG. 13, the first optical element 55f of the combining optical system 55 is disposed in front of the diffraction grating 154R. As described above, the first optical element 55f is configured to transmit red light. Accordingly, the first light LRA formed in the predetermined light distribution pattern by the diffraction grating 154R is transmitted through the first optical element 55f and propagates forward. Further, the first optical element 55f is disposed above the diffraction grating 154G. As described above, the first optical element 55f is configured to reflect green light. Further, the first optical element 55f is inclined by approximately 45 ° with respect to the vertical direction. Therefore, the second light LGA formed in the predetermined light distribution pattern by the diffraction grating 154G is reflected by the first optical element 55f, turned 90 °, and propagates forward.

The second optical element 55s of the composite optical system 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. Accordingly, the first light LRA and the second light LGA emitted from the first optical element 55f are transmitted through the second optical element 55s. The second optical element 55s is disposed above the diffraction grating 154B. As described above, the second optical element 55s is configured to reflect blue light. Further, the second optical element 55s is inclined by approximately 45 ° with respect to the vertical direction. Therefore, the third light LBA formed in the predetermined light distribution pattern by the diffraction grating 154B is reflected by the second optical element 55s and turned 90 °. Thereby, the first light LRA, the second light LGA, and the third light LBA are combined to generate white light. The white light propagates forward and exits from the opening 40H of the case 40, and further exits from the vehicle headlamp 1 as a low beam L via the front cover 12. As described above, the shape and light intensity distribution of the first light LRA, the shape and light intensity distribution of the second light LGA, and the shape of the light distribution pattern of the third light LBA The light intensity distribution is the same. Accordingly, the shape and light intensity distribution of the light distribution pattern of the low beam L can be the same as the shape and light intensity distribution of the light distribution pattern of the first light LRA, the second light LGA, and the third light LBA.

In the present embodiment, the low beam L shown in FIG. 4A is emitted from the vehicle headlamp 1 and irradiates an object to be irradiated such as a road surface.

By the way, since there are irregularities in the irradiated object such as the road surface, when the low beam L is irradiated to the irradiated object, the light scattered on the irradiated surface of the irradiated object is affected by the unevenness. There is a problem that speckles occur due to mutual interference. However, according to the present embodiment, this speckle, that is, flickering of light is suppressed for the following reason.

As described above, the MEMS mirror 80R swings. Therefore, as shown in FIG. 16, the optical path of the laser light emitted from the MEMS mirror 80R, that is, the optical path of the first light LRA changes with time in synchronization with this peristalsis. Similarly, the MEMS mirror 80G swings. Therefore, the optical path of the laser light emitted from the MEMS mirror 80G, that is, the optical path of the second light LGA changes with time in synchronization with this peristalsis. Similarly, the MEMS mirror 80B swings. Therefore, the optical path of the laser light emitted from the MEMS mirror 80B, that is, the optical path of the third light LBA changes with time in synchronization with this peristalsis. In other words, the optical path of the low beam L generated from the first light LRA, the second light LGA, and the third light LBA changes with time in synchronization with the swinging of the MEMS mirrors 80R, 80G, and 80B. . As the optical path of the low beam L changes with time in this way, the incident angle and phase of light incident on the same position of the irradiated object can change with time. Then, by continuously changing the incident angle and the phase of the light, various interference patterns are generated from the reflected light reflected at the same position of the irradiated object, and the light of these interference patterns is superimposed. As a result, speckles become inconspicuous and light flickering can be suppressed.

In addition, it is preferable that the frequency of the vibration which MEMS mirror 80R, 80G, 80B gives to the optical path of light is 15 Hz or more from a viewpoint of suppressing the flicker of light. The human visual temporal resolution is approximately 30 Hz. In the case of a vehicular lamp, flickering of light can be suppressed if the frequency of vibration is about half of this frequency. In addition, if the frequency of the vibration which these vibration provision parts give is 30 Hz or more, it will generally exceed the time resolution of human vision. Therefore, the flickering of light can be further suppressed. Furthermore, if this frequency is 60 Hz or more, it is preferable from the viewpoint of further suppressing the flickering of light. In addition, the frequency of the vibration which MEMS mirror 80R, 80G, 80B gives to the optical path of light may be made into a mutually different frequency, and may be made into the same frequency.

Incidentally, as shown in FIG. 15 and FIG. 16, it is preferable that the MEMS mirror vibrates the optical path of light by at least one of the diffraction grating patterns 170 as shown in FIGS. By doing so, the amplitude of the optical path oscillated by the MEMS mirror is increased, and the change in the incident angle and phase of the light incident on the irradiated surface is increased, so that the flickering of light can be more effectively suppressed.

As described above, the vehicle headlamp 1 according to the present embodiment as the third aspect includes the diffraction gratings 154R, 154G, and 154B that are light distribution pattern forming elements that form the light distribution pattern of the low beam L. The light distribution pattern of the low beam L can be formed without using a shade. That is, it is not necessary to secure a space for using the shade, and the apparatus can be downsized.

In addition, the vehicle headlamp 1 of the present embodiment as the third aspect is a MEMS mirror 80R, 80G, 80B, which is a movable reflecting member that reflects light and vibrates the optical path of the light by moving a movable reflecting surface. Therefore, flickering of the low beam L is suppressed.

Further, in the present embodiment as the third aspect, since three lights having different wavelengths are combined, light of a desired color is emitted by adjusting the light intensity emitted from each light source. be able to.

In the present embodiment as the third aspect, since the MEMS mirror swings in two directions, more interference patterns are formed as compared with the case where the MEMS mirror swings in only one direction. Therefore, the flickering of light can be more effectively suppressed.

(Seventh embodiment)
Next, a seventh embodiment as the third aspect of the present invention will be described in detail with reference to FIG. Note that components that are the same as or equivalent to those in the sixth embodiment are denoted by the same reference numerals unless otherwise described, and redundant descriptions are omitted.

FIG. 17 is a view showing the optical system unit 150 of the vehicle headlamp according to the present embodiment in the same manner as FIG. As shown in FIG. 17, according to the vehicle headlamp optical system unit 150 of the present embodiment, the first light source 52R, the second light source 52G, and the third light source 52B are arranged in the vertical direction on the opposite side of the opening 40H. Arranged side by side. That is, laser light is emitted in the vertical direction from each of the light sources 52R, 52G, and 52B. Corresponding to the fact that the light sources 52R, 52G, 52B are arranged in the vertical direction, the MEMS mirrors 80R, 80G, 80B are arranged in the vertical direction, and the diffraction gratings 154R, 154G, 154B are arranged in the vertical direction. Arranged side by side.

According to such a configuration, the laser beams emitted from the light sources 52R, 52G, and 52B are reflected forward by the MEMS mirrors 80R, 80G, and 80B, respectively, and then forward through the diffraction gratings 154R, 154G, and 154B. To Penetrate. Then, the first light LRA, the second light LGA, and the third light LBA emitted from the diffraction gratings 154R, 154G, and 154B propagate forward toward the opening 40H. At this time, the first light LRA, the second light LGA, and the third light LBA are irradiated so that the regions irradiated with the respective lights overlap each other at a focal position that is a predetermined distance away from the vehicle. The This focal position is, for example, a position 25 m away from the vehicle.

Even with such a configuration, it is possible to suppress flickering of light while reducing the size as in the sixth embodiment as the third aspect. Further, according to the present embodiment, since the laser light is emitted from each of the light sources 52R, 52G, and 52B to the front, that is, toward the opening 40H, the combining optical system is provided to direct all the laser light to the opening 40H. There is no need. Therefore, it can be set as a simple structure compared with 6th Embodiment.

(Eighth embodiment)
Next, an eighth embodiment as a third aspect of the present invention will be described in detail with reference to FIGS. Note that components that are the same as or equivalent to those in the sixth embodiment are denoted by the same reference numerals unless otherwise described, and redundant descriptions are omitted.

FIG. 18 is a view showing a part of the optical system unit 50 of the vehicle headlamp according to the present embodiment in the same manner as FIG. As shown in FIG. 18, the optical system unit 50 of the vehicle headlamp in this embodiment includes the first MEMS mirror 280R instead of the first MEMS mirror 80R in the sixth embodiment. Different from the system unit 50. The MEMS mirror 280R includes a substrate 282 and a reflective layer 281R as a movable reflective surface as main components. A main portion 284 that is a portion other than both end portions 283 of the substrate 282 is formed thinner than both end portions 283. Thus, the main portion 284 is configured to have flexibility. On one surface of the main part 284, the reflective layer 281R as the movable reflective surface described above is formed. The reflective layer 281R may be made of silver, for example. In addition, a piezoelectric element (not shown) is disposed in the portion of the main portion 284 where the reflective layer 281R is located. According to such a configuration, by adjusting the voltage applied to the piezoelectric element, the main portion 284 and the reflective layer 281R can be bent according to the voltage. That is, the curvature of the reflective layer 281R can change according to the voltage applied to the piezoelectric element. Therefore, according to the present embodiment, as shown in FIG. 19, the laser beam can vibrate in the radial direction by changing the curvature of the reflective layer 281R. That is, the optical path of the first light LRA emitted from the diffraction grating 154R can vibrate in the radial direction. The MEMS mirrors 80G and 80B may have the same configuration as the MEMS mirror 280R.

(Ninth embodiment)
Next, a ninth embodiment as a third aspect of the present invention will be described in detail with reference to FIG. Note that components that are the same as or equivalent to those in the sixth embodiment are denoted by the same reference numerals unless otherwise described, and redundant descriptions are omitted.

FIG. 20 is a view showing the vicinity of the second light source 52G in the optical system unit 50 of the vehicle headlamp according to the present embodiment in the same manner as FIG. As shown in FIG. 20, the optical system unit 50 of the vehicle headlamp in the present embodiment is configured such that the laser light emitted from the second diffraction grating 154G is reflected by the second MEMS mirror 80G. Different from the optical system unit 50 in the sixth embodiment. More specifically, in the optical system unit 50 according to the ninth embodiment, the second diffraction grating 154G is disposed above the second collimating lens 53G, and the second MEMS mirror 80G is disposed above the second diffraction grating 154G. The According to such a configuration, the second light LGA transmitted through the diffraction grating 154G and having a predetermined light distribution pattern is reflected by the second MEMS mirror 80G and propagates forward. According to such a configuration, since the optical path of the second light LGA vibrates when the movable reflecting surface 81R of the second MEMS mirror 80G swings, flickering of light can be suppressed as in the first embodiment.

13 is compared with the ninth embodiment shown in FIG. 20, the vehicular headlamp 1 according to the sixth embodiment reflects the laser light by the MEMS mirror 80G. Since it is configured to enter the diffraction grating 154G, the MEMS mirror 80G can be brought closer to the light source 52G as compared with the vehicle headlamp according to the ninth embodiment. Therefore, in the sixth embodiment, the movable reflecting surface 81G of the MEMS mirror 80G can be made smaller than in the ninth embodiment.

In the sixth to ninth embodiments as the third aspect described above, the vehicle headlamp 1 as the vehicle lamp is assumed to irradiate the low beam L, but the third embodiment of the present invention The vehicle lamp as an aspect is not particularly limited. For example, the vehicular lamp in another embodiment as the third aspect has an intensity higher than that of the low beam L in a region indicated by a broken line in FIG. 4A, that is, a region above the region irradiated with the low beam L. It may be configured to irradiate with low light. Such low-intensity light is, for example, light OHS for label recognition. In this case, it is preferable that the light OHS for label | marker recognition is contained in the light radiate | emitted from each diffraction grating 154R, 154G, 154B. Moreover, the vehicle lamp in other another embodiment may be comprised so that a high beam as shown to FIG. 4 (B) may be irradiated. Furthermore, in another embodiment as the third aspect, the vehicular lamp according to the present invention may be applied as one constituting 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 sixth to ninth embodiments as the third aspect described above, the diffraction grating is composed of a plurality of diffraction grating patterns, and the MEMS mirror vibrates one or more optical paths of the spectrum of the diffraction grating pattern. As described above, even when the MEMS mirror vibrates the optical path of light by less than one of the diffraction grating patterns, the light flickering can be suppressed. Alternatively, the diffraction grating may be formed from a single diffraction grating pattern. In the case where the diffraction grating is formed from a single diffraction grating pattern, this single diffraction grating is formed in a region irradiated with light in order to form a low beam L light distribution pattern which is a predetermined light distribution pattern. Preferably all the patterns are included.

Further, in the sixth to ninth embodiments as the third aspect described above, an example including three light sources, three MEMS mirrors corresponding to the three light sources, and three diffraction gratings has been described. As the third aspect, at least one light source is sufficient, and correspondingly, at least one MEMS mirror and diffraction grating are sufficient. However, as described above, it is possible to generate light of a desired color by providing three light sources.

Further, in the sixth to ninth embodiments as the third aspect described above, the example using the diffraction grating as the light distribution pattern forming element has been described, but in the other embodiments as the third aspect, LCOS may be used as the light distribution pattern forming element.

In the sixth to ninth embodiments as the third aspect described above, the light distribution pattern forming element transmits light. However, the light distribution pattern forming element is configured to reflect light. May be.

Further, in the sixth to ninth embodiments as the third aspect described above, the example in which the MEMS mirror is used as the movable reflecting member has been described. However, the present invention is not limited to this. For example, in another embodiment as the third aspect, a polygon lens may be used as the movable reflecting member.

As described above, according to the first aspect of the present invention, there is provided a vehicular lamp that can suppress color blur, and according to the second aspect of the present invention, it is possible to suppress light flickering. According to the third aspect of the present invention, there is provided a vehicular lamp that can suppress light flickering while being reduced in size, and is used in the field of vehicular lamps such as automobiles. Is possible.

1 ... Vehicle headlamp (vehicle lamp)
DESCRIPTION OF SYMBOLS 10 ... Case 20 ... Lamp unit 21 ... Light source 22 ... Phase modulation element 40 ... Case 41 ... Base 50, 150 ... Optical system unit 51R ... 1st Light emitting optical system 51G ... second light emitting optical system 51B ... third light emitting optical system 52R ... first light source 52G ... second light source 52B ... third light sources 53R, 53G, 53B ... Collimating lens 54R ... first phase modulation element 54G ... second phase modulation element 54B ... third phase modulation element 55 ... synthetic optical system 55f ... first optical element 55s ... second Optical element 60... Mirror body 70... Control unit 72... Input unit 80R, 280R... First MEMS mirror (movable reflection member)
80G ... Second MEMS mirror (movable reflective member)
80B ... Third MEMS mirror (movable reflective member)
81R, 81G, 81B ... movable reflective surface 281R ... reflective layer 154R ... first diffraction grating (light distribution pattern forming element)
154G ... Second diffraction grating (light distribution pattern forming element)
154B ... Third diffraction grating (light distribution pattern forming element)
170: Diffraction grating pattern LR, LG, LB: Laser light

Claims (21)

1. A phase modulation element capable of changing the light distribution pattern of the emitted light while diffracting and emitting the incident light; and
   A light source that emits a plurality of laser beams having different wavelengths in a time-sharing manner;
   With
   The laser light of each wavelength emitted from the light source is incident on the phase modulation element,
   The phase modulation element diffracts and emits the laser beam with a phase modulation pattern corresponding to the laser beam of each wavelength,
   A vehicular lamp characterized in that regions irradiated with light emitted from the phase modulation element corresponding to the laser beams of respective wavelengths overlap each other.
2. 2. The vehicular lamp according to claim 1, wherein at least a part of an outer shape of a region irradiated with light emitted from the phase modulation element corresponds to the laser light having each wavelength.
3. The vehicular lamp according to claim 1, wherein the phase modulation element is a transmissive phase modulation element.
4. The vehicular lamp according to claim 1, wherein the phase modulation element is a reflection type phase modulation element.
5. The vehicular lamp according to any one of claims 1 to 4, wherein the light source emits at least three laser beams having different wavelengths.
6. A light source that emits light of a predetermined wavelength;
   A phase modulation element that diffracts and emits light emitted from the light source in a phase modulation pattern that changes at a time interval shorter than a predetermined time interval;
   With
   A vehicular lamp characterized in that regions irradiated with light emitted from the phase modulation elements having different phase modulation patterns overlap each other.
7. The vehicular lamp according to claim 6, wherein a region irradiated with light emitted from the phase modulation element vibrates in a predetermined direction corresponding to a change in the phase modulation pattern.
8. The vehicular lamp according to claim 6 or 7, wherein an intensity distribution in a light distribution pattern of light emitted from the phase modulation element changes corresponding to a change in the phase modulation pattern.
9. The vehicular lamp according to any one of claims 6 to 8, wherein the predetermined time interval is 1/15 s or less.
10. The vehicular lamp according to claim 6, wherein the phase modulation element is a transmission type phase modulation element.
11. The vehicular lamp according to any one of claims 6 to 9, wherein the phase modulation element is a reflection type phase modulation element.
12. A light source that emits light of a predetermined wavelength;
    A light distribution pattern forming element that generates light having a predetermined light distribution pattern by changing a traveling direction of at least a part of the light;
    A movable reflective member having a movable reflective surface and moving the movable reflective surface to vibrate the optical path of the light;
    A vehicular lamp characterized by comprising:
13. The vehicular lamp according to claim 12, wherein the movable reflecting surface of the movable reflecting member reflects the light emitted from the light source toward the light distribution pattern forming element.
14. The vehicular lamp according to claim 12, wherein the movable reflecting surface of the movable reflecting member reflects the light emitted from the light distribution pattern forming element.
15. The vehicular lamp according to any one of claims 12 to 14, wherein the movable reflecting member is a MEMS mirror.
16. The vehicular lamp according to any one of claims 12 to 15, wherein the movable reflection member vibrates the optical path of the light in two or more directions.
17. The vehicular lamp according to any one of claims 12 to 16, wherein the movable reflecting member vibrates the optical path of the light at a frequency of 15 Hz or more.
18. The light distribution pattern forming element is a diffraction grating composed of a diffraction grating pattern formed in each of a plurality of divided regions,
    18. The movable reflecting member according to claim 12, wherein the light reflecting path vibrates at least one of the diffraction grating patterns on the incident surface of the light distribution pattern forming element. The vehicle lamp as described.
19. 18. The vehicular lamp according to any one of claims 12 to 17, wherein the light distribution pattern forming element is LCOS (Liquid Crystal On Silicon).
20. The vehicular lamp according to any one of claims 12 to 19, wherein the movable reflecting member vibrates the optical path of the light by swinging the movable reflecting surface about at least one axis.
21. The vehicular lamp according to any one of claims 12 to 19, wherein the movable reflecting member vibrates an optical path of the light by changing a curvature of the movable reflecting surface.
    
    

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