Adaptive laser vehicle light
The adaptive laser headlight, composed of a reflective wavelength conversion unit and a freeform reflector bowl, solves the problems of insufficient brightness and complex structure of traditional pixelated headlights, achieving a high-brightness, low-volume, and low-cost adaptive lighting effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- APPOTRONICS CORP LTD
- Filing Date
- 2020-04-27
- Publication Date
- 2026-06-23
AI Technical Summary
Traditional pixelated headlights suffer from insufficient optical brightness, complex overall structure, low imaging resolution and contrast, and low light utilization, resulting in large headlight size, high cost, and difficulty in widespread application.
The adaptive laser car light, composed of a reflective wavelength conversion unit, a freeform reflector bowl or lens, and a digital micromirror array, achieves intensity gradient distribution and efficient modulation of light through a non-uniform light generation unit and a spatial light modulator, thereby reducing the number of optical components and improving light utilization and imaging resolution.
This has resulted in a high-brightness, low-volume, and low-cost adaptive laser headlight, which improves light utilization and imaging resolution, reduces headlight size and cost, and expands its application range.
Smart Images
Figure CN122258317A_ABST
Abstract
Description
[0001] This application is a divisional application of application number 202010341862.6, filed on April 27, 2020, entitled "An Adaptive Laser Vehicle Light". Technical Field
[0002] This invention relates to the field of lighting technology, and in particular to an adaptive laser vehicle light. Background Technology
[0003] Currently, in the field of automotive lighting, traditional mechanical adaptive headlights have low adjustment precision, leading to the development of pixelated headlights. However, traditional pixelated headlights generally use LED light sources and combine them with high-resolution light modulation devices to form LED matrix pixelated headlights, which can achieve precise control over the angle of light and dark areas.
[0004] However, due to the insufficient brightness of LED light sources, using fewer LED light sources will result in low precision in controlling the angle of light and dark areas, leading to low resolution. Conversely, in order to obtain a higher resolution light distribution, multiple LED light sources are used. However, because the light emitted from multiple LED light sources has a large spread, it is necessary to use a smaller F# and a larger imaging lens to project the modulated light spot. This not only reduces the overall contrast of the headlight but also significantly increases the size and cost of the headlight, which is not conducive to the application and promotion of pixelated headlights.
[0005] Meanwhile, since pixelated headlight technology mainly uses light modulation devices to map uniform light into non-uniform light and project it onto the lighting area, it not only causes the problem of low overall headlight contrast, but also causes technical problems of low light utilization and large light energy loss.
[0006] Therefore, there is a need to develop a pixelated vehicle headlight solution with high optical brightness, simple overall structure, high imaging resolution and contrast, and high light utilization, so as to reduce the overall size and cost of the vehicle headlight and expand the application scenarios and scope of pixelated vehicle headlights. Summary of the Invention
[0007] To address the shortcomings of existing automotive headlights, such as large size, high application cost, low contrast, and significant light loss, this invention provides an adaptive laser headlight with high optical brightness, simple overall structure, high imaging resolution and contrast, and high light utilization. The headlight includes an excitation source, a white light generation unit, a non-uniform light generation unit, a spatial light modulator, and an imaging lens. The white light generation unit includes a wavelength conversion unit, which is a reflective structure used to convert the excitation light emitted by the excitation source into absorbed laser light. The absorbed laser light and the unabsorbed excitation light are reflected by the wavelength conversion unit along a preset direction to form a first light beam. The non-uniform light generating unit is used to collect the first light. The non-uniform light generating unit includes a freeform surface reflector or a freeform surface lens, which is used to map the first light into a second light with an intensity gradient, and then illuminate the spatial light modulator with the second light. The spatial light modulator controls the modulation of the second light according to the intensity gradient distribution of the second light, and emits a third light. The third light is illuminated by the imaging lens, and the imaging lens images the third light onto the low beam area or high beam area outside the adaptive laser headlight to form the adaptive illumination of the adaptive laser headlight.
[0008] Compared with the prior art, the present invention has the following beneficial effects: The adaptive laser headlight provided by the present invention can obtain a second light with an intensity gradient distribution, enabling the spatial light modulator to perform different image modulations for different intensity gradient distributions of the second light. Since the spatial light modulator can perform different modulations for different intensity distributions, rather than performing the same image modulation for uniform light, unnecessary light waste can be effectively avoided, thereby improving the light utilization rate of the headlight. At the same time, with the help of the non-uniform light generation unit, the adaptive laser headlight of the present invention can effectively collect the first light emitted by the white light generation unit and convert it into a second light with an intensity gradient distribution. The two functions of beam collection and light distribution control are integrated with only one device, effectively reducing the size of the headlight. Furthermore, since the wavelength conversion unit with a reflective structure is used, compared with the combination of the wavelength conversion unit with a transmissive structure and a reflector in the prior art, the number of optical components can be reduced, and the size of the headlight can be reduced. Of course, the use of the wavelength conversion unit with a reflective structure can increase the heat dissipation capacity of the wavelength conversion unit and extend the service life of the adaptive laser headlight provided by the present invention.
[0009] In one embodiment, the non-uniform light generating unit includes a freeform surface reflector bowl. The reflective arc surface of the freeform surface reflector bowl faces the wavelength conversion unit, and a through hole is provided at the center of the freeform surface reflector bowl. The excitation light passes through the through hole and illuminates the wavelength conversion unit. Since the excitation light passes through the through hole and illuminates the wavelength conversion unit, the wavelength conversion unit converts part of the excitation light into laser light and reflects both the laser light and the unexcited excitation light together to form first light. The first light illuminates the reflective arc surface of the freeform surface reflector bowl and is reflected by the reflective arc surface of the freeform surface reflector bowl. After two reflections, the light transmission displacement is reduced while the light propagation path remains unchanged, thereby effectively reducing the size of the vehicle lamp.
[0010] In one embodiment, the spatial light modulator is a digital micromirror array (DMI). The difference between the radius of the reflective arc surface of the freeform surface reflector and the side length of the DMI is a preset value, and the angle formed by the optical axis of the freeform surface reflector and the normal of the DMI is equal to the extreme angle of the tilt of the micromirrors in the DMI. In this technical solution, because the difference between the radius of the reflective arc surface of the freeform surface reflector and the side length of the DMI is a preset value, the matching degree of the light distribution reflected by the freeform surface reflector and the light distribution illuminating the DMI is higher. Furthermore, when the angle formed by the optical axis of the freeform surface reflector and the normal of the DMI is the extreme angle of the tilt of the micromirrors in the DMI, the optical spread of the second light is optimal, resulting in the maximum F# number of the imaging lens and thus reducing the size of the headlight.
[0011] In one embodiment, the white light generating unit further includes a shaping device group, and the non-uniform light generating unit includes a freeform lens. The shaping device group illuminates the wavelength conversion unit with the excitation light emitted from the light source, and illuminates the freeform lens with the first light generated by the wavelength conversion unit. In this technical solution, the shaping device group can project the first light reflected by the wavelength conversion unit onto the freeform lens, and the freeform lens collects the first light and maps it into a second light with an intensity gradient distribution, thereby reducing the size of the vehicle lamp.
[0012] In one embodiment, the shaping device assembly includes a collecting lens assembly and a regional diaphragm, or includes a collecting lens assembly and a reflector. In this technical solution, the regional diaphragm or reflector is used to reflect the excitation light to the collecting lens assembly. The collecting lens assembly focuses the laser light onto the wavelength conversion unit and collects the first light reflected by the wavelength conversion unit, then illuminates the regional diaphragm, thereby causing the first light to illuminate the freeform lens. In this way, the excitation light can be converted and synthesized into the first light, while simultaneously mapping the first light into a second light with an intensity gradient distribution, reducing the size of the vehicle lamp.
[0013] In one embodiment, the collecting lens group includes only a first lens. The collecting function of the second lens in the collecting lens group is achieved by a freeform surface lens, which further reduces the number of optical components in the headlight and realizes the miniaturization of the headlight.
[0014] In one embodiment, the collecting lens group is replaced with a square rod. The square rod collects the excitation light reflected by the mirror and illuminates the wavelength conversion unit. It then homogenizes the first light reflected by the wavelength conversion unit and projects it onto a freeform lens to generate a second light with an intensity gradient distribution. The second light illuminates the spatial light modulator, which can effectively avoid the grainy light spots when the second light illuminates the spatial light modulator.
[0015] In one embodiment, the modulation image of the spatial light modulator is controlled to be consistent with the intensity gradient distribution of the second light. In this technical solution, because the modulation signal of the modulation image of the spatial light modulator is changed according to the different intensity gradient distribution of the second light, the matching between each modulation unit of the spatial light modulator and the modulation image is stronger, and most of the light energy can be reflected, resulting in less light energy waste and high light utilization.
[0016] Specifically, the spatial light modulator is a digital micromirror array (DMI). When the grayscale value of the modulated image is large, the proportion of time that controls the micromirrors of the DMI (i.e., the modulation units of the aforementioned spatial light modulator) to be "ON" is higher; conversely, when the grayscale value of the modulated image is small, the proportion of time that controls the micromirrors of the DMI to be "OFF" is higher. In this technical solution, because the modulation signal of the modulated image of the DMI is changed according to the different intensity gradient distribution of the second light, the matching between the "ON" and "OFF" time proportions of the DMI is stronger with the modulated image. The grayscale value of the "OFF" state is smaller, and it ensures that most of the light energy can be reflected out through the "ON" state, resulting in less light energy waste and high light utilization.
[0017] In one embodiment, the second light is obliquely incident on the spatial light modulator. The second light is corrected by calculating the corrected second light based on the modulation image distribution of the second light incident perpendicularly on the spatial light modulator and the angle at which the second light is obliquely incident on the spatial light modulator. The corrected second light is then controlled to be obliquely incident on the spatial light modulator to compensate for the distortion of the modulation image caused by the oblique incident light on the spatial light modulator. In this technical solution, by correcting the second light, the image distortion of the modulation image caused by the oblique incident light on the spatial light modulator can be corrected, thereby ensuring the modulation accuracy of the spatial light modulator and further improving light utilization.
[0018] In one embodiment, the white light generating unit further includes a light homogenizing device, which converts the excitation light generated by the excitation source into uniform excitation light. In this technical solution, by converting the excitation light generated by the excitation source into uniform excitation light, the excitation area of the wavelength conversion unit can be increased, the conversion efficiency of the wavelength conversion unit can be improved, and light loss can be reduced. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the adaptive laser vehicle lighting path according to Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the non-uniform generation unit in the adaptive laser vehicle light path of Embodiment 1 of the present invention; Figure 3 The intensity gradient image distribution generated by the non-uniform generation unit in the adaptive laser vehicle light path according to Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the adaptive laser vehicle lighting path according to Embodiment 1 of the present invention; Figure 5 This is a schematic diagram of the adaptive laser vehicle lighting path according to Embodiment 3 of the present invention; Figure 6 This is a schematic diagram of the adaptive laser vehicle lighting path according to Embodiment 4 of the present invention. Detailed Implementation
[0020] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings and descriptions. Example 1
[0021] Please see Figure 1 This is a schematic diagram of the adaptive laser vehicle light path according to Embodiment 1 of the present invention. The adaptive laser vehicle light 1 includes an excitation light source 101, a white light generating unit A, a non-uniform light generating unit B, a spatial light modulator 401, and an imaging lens 501. After the excitation light source 101 emits excitation light, it illuminates the white light generating unit A to generate a first light S1. The first light S1 is mapped by the non-uniform white light generating unit B into a second light S2 with an intensity gradient distribution. Then, the spatial light modulator 401 controls the spatial light modulator to modulate the second light S2 according to the intensity gradient distribution of the second light S2 and emits a third light S3. The third light S3 is illuminated by the imaging lens. The imaging lens 501 images the third light onto the near beam area or high beam area outside the adaptive laser vehicle light to form the adaptive illumination of the adaptive laser vehicle light.
[0022] In this embodiment, the excitation light source 101 can be, for example, a semiconductor laser diode light source. Typically, for the needs of vehicle headlight illumination, and taking cost into consideration, a blue laser diode light source can be selected.
[0023] In this embodiment, the white light generation unit includes a wavelength conversion unit 201. The wavelength conversion unit is a reflective structure used to convert the excitation light emitted by the excitation source into a laser beam. The laser beam and the unabsorbed excitation light are reflected by the wavelength conversion unit along a preset direction to form the first light S1. The wavelength conversion unit can be selected from a YAG-based yellow fluorescent material to work with a blue laser diode. This series of wavelength conversion materials has high conversion efficiency and material stability, and can emit yellow excitation light under blue light excitation, which combines with the remaining unexcited blue laser beam to form the first light S1. Preferably, the wavelength conversion unit can be an organic fluorescent structure encapsulated in silicone or epoxy resin, an inorganic fluorescent structure encapsulated in glass, or a fluorescent ceramic, such as single-crystal Ce:YAG or polycrystalline Ce:YAG, or a ceramic fluorescent structure encapsulated in a transparent ceramic material (such as alumina).
[0024] To further ensure the normal operation of the wavelength conversion unit, a high thermal conductivity material can also be attached to the wavelength conversion unit to dissipate the heat borne by the phosphor layer on the wavelength conversion unit 201. The high thermal conductivity material can be one or more of the following: thermally conductive adhesive, thermally conductive silicone, phase change material, etc.
[0025] It is worth mentioning that, in order to meet different vehicle lighting needs and conditions, other wavelength light sources can also be selected in combination with wavelength conversion units to generate the first light S1.
[0026] In this embodiment, the white light generation unit may further include a light homogenizing device 202, which converts the excitation light generated by the excitation source 101 into uniform excitation light. Preferably, the light homogenizing device may be a combination of a microlens array / compound eye and a focusing lens. In this technical solution, by converting the excitation light generated by the excitation source 101 into uniform excitation light, the excitation area of the wavelength conversion unit illuminated by the excitation light can be increased, the conversion efficiency of the wavelength conversion unit 201 can be improved, and light loss can be reduced.
[0027] In this embodiment, the non-uniform light generating unit is used to collect the first light S1 and map the first light S1 into a second light S2 with an intensity gradient, and then the second light S2 is used to illuminate the spatial light modulator 401; as Figure 2The diagram shows a structural schematic of the non-uniform light generation unit in the adaptive laser vehicle lighting path of the present invention. In this embodiment, the non-uniform light generation unit includes a freeform surface reflector bowl 301. The reflective arc surface 3011 of the freeform surface reflector bowl faces the wavelength conversion unit 201, and a through hole 3012 is provided in the center of the freeform surface reflector bowl. Excitation light passes through the through hole 3012 and irradiates the wavelength conversion unit 201. The wavelength conversion unit 201 excites the excitation light into laser light, which, together with the unexcited excitation light, is reflected in a Lambertian emission manner to generate a first light S1, which then irradiates the reflective arc surface 3011 of the freeform surface reflector bowl. In this embodiment, through the cooperation of the wavelength conversion unit 201 and the freeform surface reflector bowl, only two reflections are needed to map the excitation light into a second light S1 with an intensity gradient without changing the incident direction of the excitation light or the path length of the light. 2. The structure is simple and the size of the headlight is effectively reduced; In this embodiment, the angle of the reflective arc surface 3011 of the freeform reflector bowl 301 is controllable, so the angle of the incident beam and the output range can be changed. Preferably, the freeform reflector bowl 301 can reflect all the laser and excitation light reflected by the wavelength conversion unit 201. The material of the freeform reflector bowl is preferably a metal material with low density, which can achieve high thermal conductivity while effectively reducing the weight of the headlight. Preferably, the material of the freeform reflector bowl is aluminum or aluminum alloy.
[0028] In this embodiment, the spatial light modulator is based on, as follows Figure 3The intensity gradient distribution of the second light S2 shown controls the spatial light modulator to modulate the second light S2 and emit the third light S3. Preferably, the spatial light modulator is a DMD (Digital Micromirror Device), which includes multiple micromirrors as modulation units for the incident light, with each group of micromirrors forming a modulation region. Preferably, the difference between the radius of the reflective arc surface of the DMD and the side length of the freeform surface reflector bowl is a preset value, ranging from 0 to 2 micrometers. The smaller the preset value, the higher the matching degree of the light distribution of the second light distribution S2 reflected by the freeform surface reflector bowl and illuminating the DMD. Even better, when the DMD is working, the DMD controller applies a reset pulse of "1" or "0" to each micromirror, so that each micromirror is in a corresponding ±α° state (α=12 or α=12). In the projection system, the +α° state corresponds to the "on" pixel (i.e., the "ON" state). Under the "on" pixel, the incident light can be reflected to the back-end optical system and exited through the transmission device after shining on the micromirror. Correspondingly, the -α° state corresponds to the "off" pixel (i.e., the "OFF" state). Under the "off" pixel, the incident light shining on the micromirror cannot enter the back-end optical system and is absorbed and consumed by the vehicle lighting system. Therefore, when the angle formed by the optical axis of the freeform reflector bowl and the DMD normal O is 2α° (the extreme angle at which each micromirror can rotate, i.e., the difference between the maximum and minimum angles of each micromirror's flip, α° and -α°), the optical spread of the second light S2 is optimal, and it can illuminate the DMD to the maximum extent, thereby maximizing the F# number of the imaging lens and reducing the size of the headlight; in this embodiment, the intensity gradient distribution of the modulated image of the DMD is controlled to be consistent with that of the second light, such as... Figure 3 As shown, when the grayscale value of the modulated image is large, that is... Figure 3 During the peak region of the modulation image, the micromirrors controlling the DMD are "ON" for a higher percentage of the time. At this time, beams with higher grayscale values can be smoothly reflected by the micromirrors to the back-end optical system, ensuring the effective utilization of high-energy beams. The light transmittance reaches its upper limit, i.e., as close to 100% as possible (since light loss during transmission through a medium or interface is unavoidable, 100% light transmittance is the ideal value; therefore, the upper limit here refers to the maximum light transmittance excluding unavoidable light loss). It is worth mentioning that the DMD can adjust the flip state of each micromirror according to the grayscale value of the modulated image, so that different grayscale values correspond to different flip angles of the micromirrors, thereby maximizing the "ON" time percentage of the overall modulated image and thus maximizing the light transmittance. When the grayscale value of the modulated image is low, i.e., Figure 3During the valley region, the micromirrors of the DMD are controlled to be in the "OFF" state to ensure that the energy loss of light is minimized in the OFF state. This operation allows for a higher degree of matching between the "ON" and "OFF" time proportions of the DMD and the different grayscale values of the modulated image. The grayscale value loss in the "OFF" state is smaller, ensuring that most of the light energy can be reflected out through the "ON" state, improving the overall light transmittance of the modulated image, ultimately resulting in less light energy waste and higher light utilization.
[0029] Preferably, the second light distribution S2 can be corrected to reduce the image distortion of the modulated image caused by the second light obliquely incident on the DMD. Specifically, the corrected second light is calculated based on the modulated image distribution of the second light normally incident on the DMD and the angle of the second light obliquely incident on the DMD, and the corrected second light is controlled to obliquely incident on the DMD to compensate for the distortion of the modulated image caused by the second light obliquely incident on the DMD.
[0030] Of course, in order to achieve high-resolution vehicle headlight illumination, the spatial light modulator can also be other high-resolution modulation devices, such as LCD (Liquid Crystal Display) and LC-SLM (Liquid Crystal Spatial Light Modulator).
[0031] When the spatial light modulator is a transmissive LCD, the liquid crystal cells of the LCD control the light transmittance to control the light transmission rate. Based on the intensity gradient distribution of the second light S2, the light transmittance of the LCD's liquid crystal cells is controlled, thereby allowing images with higher grayscale values to pass through the LCD as much as possible, thus improving light utilization. Correspondingly, since the LCD is a transmissive LCD, the optical path of the LCD and the subsequent third light S3 can be modified accordingly. For example, the relative position of the LCD and the freeform reflector bowl 202 can be modified to ensure that the second light S2 illuminates the transmissive LCD as much as possible; the lens S3 can be placed at the rear end of the optical path of the transmissive LCD; and devices such as mirrors can be used to reflect the illumination beam again to reduce the overall size of the headlight.
[0032] When the spatial light modulator is an LC-SLM, the pixel unit of the LC-SLM controls the light transmittance by controlling the reflectivity of light. Based on the intensity gradient distribution of the second light S2, it controls the reflectivity of the pixel unit of the liquid crystal cell of the LC-SLM, so that the image with a larger gray value is reflected by the LC-SLM as much as possible, thereby improving the light utilization rate. When using an LC-SLM, the light source 101 can be changed to a linearly polarized laser to maximize the energy of the polarized light incident on the LC-SLM and minimize the waste of light energy.
[0033] In this embodiment, since the adaptive laser headlight 1 has high brightness and small optical expansion, a small F# imaging lens 501 can be used; when the third light S3 is irradiated by the imaging lens 501, the imaging lens 501 images the third light S3 onto the low beam area or high beam area outside the adaptive laser headlight, forming adaptive headlight illumination of the adaptive laser headlight 1 that meets the illumination angle and range required by automotive standards.
[0034] Please refer to Example 2 Figure 4 This is a schematic diagram of the adaptive laser vehicle light path according to Embodiment 2 of the present invention. The adaptive laser vehicle light 1a includes an excitation light source 101a, a white light generating unit A, a non-uniform light generating unit B, a spatial light modulator 401a, and an imaging lens 501a. The white light generating unit includes 201a, a light homogenizing device 202a, and a shaping device group (not shown in the figure). The shaping device group includes a collecting lens group (including a first lens 205a and a second lens 204a) and a regional diaphragm 203a. The angle between the normal O1 of the regional diaphragm 203a and the transmission direction of the excitation light from the light source is 45°, and the central region of the regional diaphragm 203a is a reflective region, while the two end regions are transmissive regions. The non-uniform light generating unit B is a freeform surface lens 301a.
[0035] During operation, the excitation light emitted from the light source 101a is homogenized by the light homogenizer 202a and then irradiates the reflective area of the region diaphragm 203a of the shaping device group. The region diaphragm 203a reflects the laser light and passes through the collecting lens group (second lens 204a, first lens 205a) before irradiating the wavelength conversion unit 201a. The wavelength conversion unit 201a converts part of the excitation light into laser light and unabsorbed excitation light, which are reflected together along a preset direction. After being collected by the collecting lens group, the light is emitted through the transmission area of the region diaphragm 203a to form the first light S1. After the above process, the shaping device group illuminates the first light S1 generated by the wavelength conversion unit 201a onto the freeform lens 301a. The freeform lens 301a maps the first light S1 into a second light S2 with an intensity gradient distribution. Then, the spatial light modulator 401a controls the spatial light modulator to modulate the second light S2 according to the intensity gradient distribution of the second light S2 and emits a third light S3. The third light S3 is illuminated by the imaging lens 501a, which images the third light onto the low beam or high beam area outside the adaptive laser headlight to form the adaptive lighting of the adaptive laser headlight.
[0036] The difference between this embodiment and embodiment one is that the non-uniform light generating unit B is a freeform lens 301a and includes a shaping device group. Therefore, the position of the freeform lens 301a is not restricted. Depending on the different parameters of the freeform lens 301a, it is placed as close as possible to or inside the shaping device group. After the shaping device group projects the first light S1 reflected by the wavelength conversion unit onto the freeform lens 301a, the freeform lens 301a can collect the first light S1 and map it into a second light S2 with an intensity gradient distribution, thereby reducing the size of the headlight and improving the design freedom of the adaptive laser headlight. Example 3
[0037] Please see Figure 5 This is a schematic diagram of the adaptive laser vehicle light path according to Embodiment 3 of the present invention. The adaptive laser vehicle light 1b includes an excitation light source 101b, a white light generating unit A, a non-uniform light generating unit B, a spatial light modulator 401b, and an imaging lens 501b. The white light generating unit includes a 201b, a homogenizing device 202b, and a shaping device group (not shown in the figure). The shaping device group includes a first lens 205b and a regional diaphragm. The angle between the normal O2 of the regional diaphragm and the transmission direction of the excitation light from the light source is less than 45°, and the central region of the regional diaphragm is a reflective region, while the two end regions are transmission regions. The regional diaphragm can also be replaced by a reflector 203b. The reflector 203b is used to reflect the excitation light emitted from the light source 101b to the rear optical system. Simultaneously, the reflector 203b should be positioned as low as possible within the shaping device group to avoid blocking the light beam reflected by the wavelength conversion unit 201b in the shaping device group. In this embodiment, the regional diaphragm is replaced by a reflector 203b. The non-uniform light generating unit B is a freeform lens 301b. The freeform lens 301b is essentially equivalent to the combination of the freeform lens 301a and the second lens 204a in the second embodiment, and the 203b is arranged in the middle of the optical path between the reflector 203b and the first lens 205b of the shaping device group. It is worth mentioning that the freeform lens 301b is a unidirectional functional device, from its positive direction ( Figure 5 When incident from left to right (positive direction), it can collect and map uniform light into a device with an intensity gradient distribution. When incident from the opposite direction, it illuminates other areas outside the freeform area of the freeform lens 301b to achieve regional distribution function, so as not to affect the gradient distribution of the incident light spot of the wavelength conversion unit.
[0038] During operation, the excitation light emitted from the light source 101b can be perpendicularly or obliquely incident on the homogenizing device 202b. After homogenization, it is incident on the reflector 203b of the shaping device group. The oblique excitation light incident on the homogenizing device 202b avoids the reflector 203b from affecting the subsequent optical path. The reflector 203b collects the laser light reflected by the laser and sequentially passes through the freeform lens 301b and the first lens 205b in the shaping device group before incidenting it on the wavelength conversion unit 201b. The wavelength conversion unit 201b converts part of the excitation light into laser light and reflects the unabsorbed excitation light along a preset direction. After passing through the first lens 205b, it forms the first light S1. After the above process, the shaping device group incidents the first light S1 generated by the wavelength conversion unit 201b onto the freeform lens 301b. The freeform lens 301b maps the first light S1 into a second light S2 with an intensity gradient distribution. Then, the spatial light modulator 401b controls the spatial light modulator to modulate the second light S2 according to the intensity gradient distribution of the second light S2, and emits a third light S3. The third light S3 is illuminated by the imaging lens 501b, and the imaging lens 501b images the third light onto the low beam or high beam area outside the adaptive laser headlight to form the adaptive lighting of the adaptive laser headlight.
[0039] The difference between this embodiment three and embodiment two is that the freeform lens 301b, which serves as the non-uniform light generating unit B, is a combination of the freeform lens 301a in embodiment two and the second lens 204a described in embodiment two, which have the function of collecting light. Furthermore, the freeform lens 301b is a unidirectional functional device, operating from its positive direction ( Figure 5 When light is incident from left to right (positive direction), it directly illuminates the freeform area of the freeform lens 301b, collecting and mapping uniform light into a device with an intensity gradient distribution. When light is incident from the opposite direction, it illuminates areas outside the freeform area of the freeform lens 301b, achieving a regional distribution function without affecting the gradient distribution of the incident light spot of the wavelength conversion unit. It can be understood that by using only one freeform lens 301b, the functions of multiple devices can be integrated, reducing the number of optical components in the optical path, thus further reducing the size of the optical path and achieving miniaturization of the vehicle headlight. Example 4
[0040] Please see Figure 6This is a schematic diagram of the adaptive laser vehicle light path according to Embodiment 4 of the present invention. The adaptive laser vehicle light 1b includes an excitation light source 101c, a white light generating unit A, a non-uniform light generating unit B, a spatial light modulator 401c, and an imaging lens 501c. The white light generating unit includes a wavelength conversion unit 201c, a light homogenizing device, and a shaping device group (not shown in the figure). The light homogenizing device is a lens 202c, used to focus the excitation light. The shaping device group includes a square rod 204c and a reflector 203c. The reflector 203c is used to reflect the excitation light emitted from the light source 101c to the rear optical system. The size of the reflector should be as small as possible, only covering the laser beam, thereby avoiding blocking the beam reflected by the wavelength conversion unit 201b in the shaping device group. The reflector 203c can also be replaced by a regional diaphragm. The angle between the normal O3 of the regional diaphragm and the transmission direction of the excitation light from the light source is less than 45°, and the central region of the regional diaphragm is a reflective region, while the two end regions are transmission regions. The non-uniform light generating unit B is a freeform surface lens 301c.
[0041] During operation, the excitation light emitted from the light source 101c is focused onto the reflector 203c of the shaping device group after passing through the lens 202c. The reflector 203c reflects the laser light and collects it through devices such as the freeform lens 301c and the square rod 204c in the shaping device group before irradiating it onto the wavelength conversion unit 201c. The wavelength conversion unit 201c converts part of the excitation light into laser light and reflects the unabsorbed excitation light along a preset direction. Then, the light is homogenized and collected by the square rod 204c to form the first light S1. After the above process, the shaping device group irradiates the first light S1 generated by the wavelength conversion unit 201c onto the freeform lens 301c. The freeform lens 301c maps the first light S1 into a second light S2 with an intensity gradient distribution. Then, the spatial light modulator 401c controls the spatial light modulator to modulate the second light S2 according to the intensity gradient distribution of the second light S2, and emits a third light S3. The third light S3 is illuminated by the imaging lens 501c, and the imaging lens 501c images the third light onto the low beam or high beam area outside the adaptive laser car light to form the adaptive lighting of the adaptive laser car light.
[0042] The difference between this embodiment four and embodiment two is that the collecting lens group described in embodiment two is replaced with a square rod. The square rod can homogenize and collect the excitation light reflected by the lens 202c and the reflector 203c, and then illuminate the wavelength conversion unit 201c, thereby maximizing the excitation efficiency of the wavelength conversion unit 201c. At the same time, the square rod can also homogenize the laser-received and unexcited excitation light (i.e., the first light S1) reflected by the wavelength conversion unit 201c, and then project it onto the freeform lens 301c to generate a second light S2 with an intensity gradient distribution. Since the first light S1 illuminating the freeform lens 301c is homogenized multiple times, the grainy light spot generated when the second light illuminates the spatial light modulator can be effectively avoided.
[0043] The adaptive laser vehicle light provided by this invention includes an excitation light source, a white light generation unit, a non-uniform light generation unit, a spatial light modulator, and an imaging lens. The white light generation unit includes a wavelength conversion unit, which is a reflective structure used to generate first light. The non-uniform white light generation unit includes a freeform surface reflector or a freeform surface lens used to collect the first light and map it into second light with an intensity gradient distribution. The spatial light modulator performs image modulation according to the intensity gradient distribution of the second light and emits third light. The imaging lens images the third light onto the near beam or high beam region to form adaptive illumination. The technical solution of this invention integrates the beam collection function and the light distribution control function with only one device, effectively reducing the size of the vehicle light.
[0044] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.
[0045] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.
Claims
1. An adaptive laser vehicle light, characterized in that, It includes an excitation light source, a white light generation unit, a non-uniform light generation unit, a spatial light modulator, and an imaging lens, among which, The white light generation unit includes a wavelength conversion unit, which is a reflective structure used to convert the excitation light emitted by the excitation source into a laser beam. The laser beam and the unabsorbed excitation light are reflected by the wavelength conversion unit along a preset direction to form the first light. The non-uniform light generating unit is used to collect the first light, and includes a freeform lens for mapping the first light into a second light with an intensity gradient, and then irradiating the second light onto the spatial light modulator; The spatial light modulator controls the modulation of the second light according to the intensity gradient distribution of the second light, and emits the third light; The third light is irradiated by the imaging lens, which images the third light onto the low beam or high beam area outside the adaptive laser headlight to form the adaptive illumination of the adaptive laser headlight.
2. The adaptive laser vehicle light according to claim 1, characterized in that, The white light generating unit further includes a shaping device group, which irradiates the wavelength conversion unit with the excitation light emitted from the light source, and irradiates the freeform lens with the first light generated by the wavelength conversion unit.
3. The adaptive laser vehicle light according to claim 2, characterized in that, The shaping device group includes a collecting lens group and a regional diaphragm, or includes a collecting lens group and a reflector.
4. The adaptive laser vehicle light according to claim 3, characterized in that, The collecting lens group includes only the first lens.
5. The adaptive laser vehicle light according to claim 3, characterized in that, Replace the collecting lens group with a square rod.
6. The adaptive laser vehicle light according to claim 1, characterized in that, The modulation image of the spatial light modulator is controlled to be consistent with the intensity gradient distribution of the second light.
7. The adaptive laser vehicle light according to claim 6, characterized in that, The second light is obliquely incident on the spatial light modulator. The second light is corrected. Based on the modulation image distribution of the second light incident perpendicularly on the spatial light modulator and the angle at which the second light is obliquely incident on the spatial light modulator, the corrected second light is calculated and controlled to be obliquely incident on the spatial light modulator to compensate for the distortion of the modulation image caused by the oblique incident on the spatial light modulator.
8. The adaptive laser vehicle light according to claim 1, characterized in that, The white light generation unit also includes a light homogenizing device, which converts the excitation light generated by the excitation source into uniform excitation light.