A vehicle-mounted holographic display device

Abstract

The present invention provides a vehicle-mounted holographic display device, an image projection device, which is used to generate a real image and generate a laser beam; at least one processing module is located on one side of the image projection device, which includes a spectroscopic unit, the spectroscopic unit is used to perform spectroscopic processing on the laser beam and generate a first light path and a second light path; a reflection unit is located on one side of the processing module and receives the first light path; and an imaging lens is located on the propagation path of the first light path and the second light path, and the imaging lens converts the real image into an enlarged virtual image; wherein the length of the optical path of the first light path and the second light path is the same, and the first light path and the second light path contain the same wavefront information. The present invention can effectively improve the problem of small visual range of the existing head-up display.

Description

Technical Field

[0001] The invention relates to a display device, and in particular to a vehicle-mounted holographic display device. Background Art

[0002] The vehicle head-up display generally generates an image source by using a display screen or projecting onto a scattering screen. The image source is installed on the dashboard, and the light emitted by the image is directed upward, and is reflected to the human eye through an inclined semi-transparent reflector above, forming a virtual image, achieving the display effect of the car information floating in front of the driver. In actual driving, under different road conditions, the distance the driver observes the road usually increases with the increase of vehicle speed. At this time, since the distance of the virtual image is usually inconsistent with the distance of objects in the external environment, the driver needs to zoom back and forth to see the virtual image and road conditions clearly during driving. Summary of the invention

[0003] In view of the above shortcomings of the prior art, an object of the present invention is to provide a vehicle-mounted holographic display device to improve the problem of a small display range of a head-up display.

[0004] To achieve the above-mentioned and other related purposes, the present invention provides a vehicle-mounted holographic display device, comprising:

[0005] An image projection device for producing a real image and generating a laser beam;

[0006] At least one processing module is located on one side of the image projection device, and includes a light splitting unit, wherein the light splitting unit is used to perform light splitting processing on the laser beam and generate a first light path and a second light path;

[0007] a reflection unit, located at one side of the processing module and receiving the first light path; and

[0008] An imaging lens is located on the propagation path of the first optical path and the second optical path, and the imaging lens converts a real image into an enlarged virtual image;

[0009] The optical paths of the first optical path and the second optical path have the same length, and the first optical path and the second optical path contain the same wavefront information.

[0010] In one embodiment of the present invention, the image projection device comprises: a light source, a speckle reducer, a collimator and a spatial light modulator, wherein the light source, the speckle reducer, the collimator and the spatial light modulator are arranged in sequence.

[0011] In one embodiment of the present invention, the light splitting unit includes a plurality of light splitters, and the light splitters are semi-transparent mirrors.

[0012] In one embodiment of the present invention, the beam splitter comprises:

[0013] A first beam splitter is located on the propagation path of the laser beam, and

[0014] The second beam splitter is located on the propagation path of the laser beam, and the angle between the second beam splitter and the first beam splitter is 45 degrees.

[0015] In an embodiment of the present invention, the reflection unit comprises a reflector located at one side of the first beam splitter, and the reflector and the second beam splitter are symmetrically arranged along the first beam splitter.

[0016] In one embodiment of the present invention, a scattering sheet is further included. The scattering sheet is located on one side of the imaging lens, and the light path passes through the scattering sheet.

[0017] In one embodiment of the present invention, the magnified virtual image formed by the imaging lens is imaged on the outside of the windshield.

[0018] In one embodiment of the present invention, the area of ​​the enlarged virtual image formed on the windshield is the eye box area, and the size of the eye box area is E. d , expressed as Wherein, k represents the magnification factor, f represents the focal length of the imaging lens, p represents the pixel pitch of the spatial light modulator, and N represents the prime number of the spatial light modulator in a one-dimensional direction.

[0019] In one embodiment of the present invention, the positional relationship between the imaging lens, the spatial light modulator and the eye box area is: Among them, f represents the focal length of the imaging lens, u represents the distance between the spatial light modulator and the imaging lens, and v represents the distance between the eye box area and the imaging lens.

[0020] In one embodiment of the present invention, the processing module further includes an extension unit, the extension unit includes a plurality of reflectors, and the reflectors are located on a propagation path of the second light path.

[0021] In summary, the present invention discloses a vehicle-mounted holographic display device, which can reconstruct images at any depth, and through the processing module, the wavefront information is divided into two identical paths. Since the spacing between the two paths is the same as the eye box range, two identical eye box ranges can be generated at adjacent positions after splitting, so that the total eye box range is magnified to twice the original, thereby improving the actual observation effect. At the same time, by increasing the number of the processing modules, the eye box range is expanded, thereby expanding the visual range of the human eye. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a schematic structural diagram of a vehicle-mounted holographic display device in one embodiment of the present invention;

[0024] Figure 2 It is a schematic diagram of the structure of multiple processing modules of a vehicle-mounted holographic display device in one embodiment of the present invention;

[0025] Figure 3 This is a schematic structural diagram of an extension unit of an on-vehicle holographic display device in one embodiment of the present invention;

[0026] Figure 4 The figure is a schematic structural diagram of an extension unit of a vehicle-mounted holographic display device in one embodiment of the present invention.

[0027] Component number description

[0028] 100. Image projection device; 101. Light source; 102. Speckle reducer; 103. Collimator; 104. Spatial light modulator;

[0029] 200, processing module; 201, first beam splitter; 202, second beam splitter; 203, first optical path; 204, second optical path;

[0030] 300, reflecting mirror; 301, first plane mirror; 302, second plane mirror;

[0031] 400, scattering sheet;

[0032] 500, imaging lens;

[0033] 600, windshield;

[0034] 700, eye box range;

[0035] 800, real image, 801, magnified virtual image;

[0036] 901, a first reflector; 902, a second reflector; 903, a third reflector; 904, a fourth reflector. DETAILED DESCRIPTION

[0037] The following is an explanation of the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the features in the following embodiments and the embodiments can be combined with each other without conflict. It should also be understood that the terms used in the embodiments of the present invention are intended to describe specific embodiments, rather than to limit the scope of protection of the present invention. The test methods for which specific conditions are not indicated in the following examples are usually carried out under conventional conditions or according to the conditions recommended by the manufacturers.

[0038] See also Figures 1 to 4 . It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0039] See also Figure 1The present invention provides a vehicle-mounted holographic display device, which can record the complete light field information for reconstruction to provide image information of all depths required by the human eye. The vehicle-mounted holographic display device can reconstruct images at any depth, that is, the distance between the virtual image generated by the vehicle-mounted holographic display device and the external environment object can be adjusted at any depth. Among them, the vehicle-mounted holographic display device is arranged in the instrument panel of the vehicle, and the holographic reconstructed image generated by it is reflected to the human eye through the windshield to form a virtual image. It should be noted that the "vehicle" mentioned here refers to a vehicle equipped with the vehicle-mounted holographic display device. The holographic reconstructed image is a three-dimensional stereoscopic image of an object obtained by reconstructing the object using holographic technology, and the three-dimensional stereoscopic image can be seen in the eye box area, while the three-dimensional stereoscopic image cannot be seen in other areas or the three-dimensional stereoscopic image seen is relatively blurred. Therefore, when the human eye is located in the eye box area, the image information generated by the holographic enhancement head-up display can enter the human eye, that is, the image information generated by the vehicle-mounted holographic display device can be observed. Among them, the eye box area represents a visible range, that is, the eye box range 700. This allows the eye box range 700 to be increased to improve the visualization effect of the image information generated by the vehicle-mounted holographic display device.

[0040] See also Figure 1 As shown, in one embodiment, the vehicle-mounted holographic display device may include an image projection device 100, a processing module 200, a reflection module and an imaging lens 500. The image projection device 100 is used to generate image information, and the processing module 200, the reflection module and the imaging lens 500 are sequentially located on the path of optical propagation of the image information.

[0041] See also Figure 1As shown, in one embodiment, the image projection device 100 is located at one side of the image projection device 100, so that the image information generated by the image projection device 100 can enter the processing module 200. The image projection device 100 may include a light source 101, a speckle attenuator 102, a collimator 103 and a spatial light modulator 104, and the light source 101, the speckle attenuator 102, the collimator 103 and the spatial light modulator 104 are arranged in sequence. Specifically, the light source 101 may be an RGB three-color laser light source or an RGB three-color LED light source, and needs to have coherence or partial coherence. Therefore, the light source 101 can be used to generate a laser beam. The speckle attenuator 102 is located at one side of the light source 101, and the laser beam can enter the speckle attenuator 102. After the laser beam enters the speckle attenuator 102, the speckle attenuator 102 can allow the laser beam to be dynamically diffused to eliminate local interference in the laser system and significantly reduce speckle noise. The collimator 103 is located between the spatial light modulator 104 and the speckle attenuator 102, so the collimator 103 can be used to collimate the divergent light beam processed by the speckle attenuator 102 and incident on the spatial light modulator 104. It should be noted that the spatial light modulator 104 is a device for modulating the amplitude or phase or complex amplitude of a light beam to generate a holographic image at any depth in space. The spatial light modulator 104 can include one of a digital micromirror device, a liquid crystal display, an amplitude-type silicon-based liquid crystal and a phase-type silicon-based liquid crystal, or a combination of these devices, but is not limited to this, and can be determined according to actual conditions. Therefore, through the spatial light modulator 104, the position of the virtual image generated by the holographic enhancement head-up display can be adjusted.

[0042] See also Figure 1 As shown, in one embodiment, the processing module 200 is located at one side of the image projection device 100, and the laser beam generated by the image projection device is allowed to enter the processing module 200. Therefore, after the laser beam enters the processing module 200, the processing module 200 processes the laser beam. Specifically, the processing module 200 allows the laser beam to be subjected to branching processing and extension processing, wherein the branching processing represents that the laser beam is divided into multiple optical paths, and the wavefront information contained in the multiple optical paths is the same, and the extension processing represents that some optical paths are extended to ensure that the path lengths of the multiple optical paths are the same.

[0043] See also Figure 1As shown, in one embodiment, the processing module 200 may allow the laser beam to be divided into two optical paths, and the two optical paths may include a first optical path 203 and a second optical path 204, and the first optical path 203 and the second optical path 204 contain the same wavefront information. The eye box area represents a visible range, namely the eye box range 700. The processing module 200 includes a plurality of beam splitters, wherein the beam splitters may include a first beam splitter 201 and a second beam splitter 202. It should be noted that the beam splitter is allowed to use a semi-transparent mirror, and the first beam splitter 201 is parallel to the spatial light modulator 104, and the second beam splitter 202 is at an angle of 45° to the spatial light modulator 104. The second beam splitter 202 is located between the first beam splitter 201 and the spatial light modulator 104. Therefore, after the laser beam is emitted from the spatial light modulator 104, the laser beam passes through the second beam splitter 202 and then vertically irradiates the first beam splitter 201. Since the first beam splitter 201 is a semi-transparent mirror, part of the laser beam passes through the first beam splitter 201 to form a first optical path 203, and part of the laser beam returns along the original direction of the laser beam and irradiates the second beam splitter 202. In particular, since the second beam splitter 202 is at an angle of 45° with the spatial light modulator 104, part of the laser beam is at an angle of 45° to the normal direction of the mirror surface of the second beam splitter 202 and irradiates the second beam splitter 202, and the second beam splitter 202 reflects the laser tube beam to form a second optical path 204. In particular, by splitting the laser beam into the first optical path 203 and the second optical path 204, the laser beam is split and processed. During the reflection process of the laser beam between the first beam splitter 201 and the second beam splitter 202, the optical path of part of the laser beam can be extended. Therefore, by extending the second optical path 204, the optical paths of the first optical path 203 and the second optical path 204 when reaching the human eye can be ensured to be consistent, and the holographic reconstructed images of different branches can be reconstructed on the same plane at the same distance from the human eye. Therefore, in this embodiment, by extending the laser beam and performing beam splitting on the laser optical path, the optical path structure can be simplified.

[0044] See also Figure 1As shown, in one embodiment, the reflection module is located at one side of the processing module 200, and the reflection module is used to reflect the first light path 203 to change the direction of the first light path 203. The reflection module may include a reflector 300, and the reflector 300 is located at one side of the processing module 200. Specifically, the first beam splitter 201 is located between the reflector 300 and the second beam splitter 202, and the reflector 300 and the second beam splitter 202 can be symmetrically arranged relative to the first beam splitter 201. Therefore, the first light path 203 is 45° with the normal direction of the mirror surface of the reflector 300, and is irradiated on the reflector 300, and after the reflector 300 reflects the first light path 203, the first light path 203 and the second light path 204 are in a parallel state.

[0045] See also Figure 1 As shown, in one embodiment, the vehicle-mounted holographic display device further includes an imaging lens 500, and the imaging lens 500 is located on the propagation path of the first optical path 203 and the second optical path 204. The imaging lens 500 may be a Fresnel lens or a holographic optical element lens, but is not limited thereto, and the imaging lens 500 may be determined according to actual needs. Specifically, when the imaging lens 500 is a holographic optical element lens, the holographic optical element lens is attached to a light blocking plate. Therefore, through the imaging lens 500, the holographic real image generated by the spatial light modulator 104 is imaged into a reproduced image, that is, an enlarged virtual image 801.

[0046] Please note that, see Figure 1 As shown, the distance between the first beam splitter 201 and the second beam splitter 202, and the distance between the first beam splitter 201 and the reflector 300 are the same and can be defined as u2. The distance between the first beam splitter 201 and the spatial light modulator 104 can be defined as u1, the distance between the reflector 300 and the imaging lens 500 can be defined as u3, and the average optical path distance of the laser beam between the spatial light modulator 104 and the imaging lens 500 can be defined as u. In one embodiment, u=u1+u2+u3.

[0047] See also Figure 1As shown, in one embodiment, the vehicle-mounted holographic display device further includes a plurality of scattering sheets 400, and the scattering sheets 400 are located on one side of the imaging lens 500. The actual number of the scattering sheets 400 is consistent with the number of the optical paths, and the scattering sheets 400 are located on the propagation path of the optical paths. In one embodiment, the scattering sheets 400 may be provided in two groups, one group of the scattering sheets 400 is located between the reflector 300 and the imaging lens 500, and the other group of the scattering sheets 400 is located between the imaging lens 500 and the processing module 200, wherein the distance between the two groups of the scattering sheets 400 and the imaging lens 500 is the same. Therefore, the scattering sheets 400 can be used to expand the size of the eye box range 700 and improve the display quality of the reconstructed image of the holographic image. The scattering sheets 400 are generally holographic scattering screens, polymer dispersed liquid crystals, random phase scattering sheets 400, metasurfaces, and photon sieves, etc., but are not limited thereto and can be determined according to actual needs.

[0048] Specifically, the virtual image generated by the imaging lens 500 can be imaged on the outside of the windshield 600, and the depth position of the virtual image relative to the windshield 600 can be adjusted. Therefore, when the virtual image generated by the imaging lens 500 enters the eye box area, the human eye can observe the virtual image generated by the image display device.

[0049] See also Figure 1 As shown, in one embodiment, the image projection device 100 is used to reconstruct a holographic wavefront to generate a reconstructed image at any depth. The wavefront generated by the image projection device 100 is divided into two wavefronts with the same information by the processing module 200. The processing module 200 also allows the wavefront to be extended to ensure that the two wavefronts reconstruct images at the same depth plane, thereby making the image generated by the image projection device 100 at the same position from the imaging lens 500 in the two optical paths.

[0050] Specifically, in one embodiment, for each light path, the diffraction angle is Wherein, p represents the pixel pitch of the spatial light modulator 104, and λ represents the wavelength of the laser beam. The positional relationship between the imaging lens 500, the spatial light modulator 104, and the eye box range 700 satisfies Wherein, f represents the focal length of the imaging lens 500 , u represents the distance between the spatial light modulator 104 and the imaging lens 500 , and v represents the distance between the eye box range 700 and the imaging lens 500 .

[0051] It should be noted that when u > f is defined, the spatial light modulator 104 forms a real image 800 behind the imaging lens 500. Therefore, when the distance u between the spatial light modulator 104 and the lens, and the focal length f of the imaging lens 500 are determined, the distance between the eye box region 700 and the imaging lens 500 can be determined. At this time, v > 0, so the eye box and the spatial light modulator 104 are respectively located on both sides of the imaging lens 500. Among them, the eye box range 700 is The N represents the number of pixels of the image of the spatial light modulator 104 in one-dimensional direction.

[0052] Specifically, when the holographic image generated by the image projection device 100 is at a distance d on one side of the imaging lens 500, the position of the reconstructed image is at u - d, and the size of the real image 800 generated by the image projection device 100 is Among them, when the condition d < f is satisfied between the real image 800 and the imaging lens 500, the real image 800 forms an enlarged virtual image 801, and the enlarged virtual image 801 is located at At. Since the is negative, the enlarged virtual image 801 is on the same side of the lens as the real image 800, and the size of the enlarged virtual image 801 is

[0053] Therefore, it is possible to allow the eye box range 700 to be expanded by setting the diffuser 400. Specifically, the expanded eye box range 700 includes Among them, k represents the magnification factor. However, it should be noted that the scattering angle of the diffuser 400 should be greater than the diffraction angle to increase the overall optical expansion amount.

[0054] In summary, under the action of the processing module 200, the wavefront information can be allowed to be divided into two identical paths, namely the first optical path 203 and the second optical path 204. Among them, the distance between the first optical path 203 and the second optical path 204 is E d , and in one embodiment, it is allowed that the distance E d is the same as the eye box range 700 expanded by the diffuser 400. Therefore, through the processing module 200, the first optical path 203 and the second optical path 204 can generate two identical eye box ranges 700 at adjacent positions. Furthermore, the eye box range 700 is enlarged to twice its original size, and the final eye box range 700 is

[0055] It should be noted that please refer to Figure 2As shown, in one embodiment, the holographic enhancement to achieve the head-up display is also allowed to have a certain expansion performance, and the expansion performance can be used to increase the size of the eye box range 700. Specifically, the expansion performance is characterized in that a plurality of processing modules 200 can be provided in the vehicle-mounted holographic display device, and the optical path is split and extended by the processing module 200 to form a plurality of optical paths. Therefore, the information covered in each optical path is the same, and each optical path can form a display image. As an example, after the light beam emitted from the spatial light modulator 104 passes through a plurality of processing modules 200, the light beam is divided into m paths. Therefore, the final eye box range 700 is expanded by m times compared to the initial eye box range 700, that is,

[0056] See also Figure 3 As shown, in one embodiment, the processing module 200 may also include a splitter unit and an extension unit, and the splitter unit and the extension unit are split structures, that is, the extension unit is located on a certain optical path to extend the optical path. Specifically, the splitter unit includes a beam splitter, and the beam splitter is located on one side of the spatial light modulator 104, so as to split the laser beam emitted from the spatial light modulator 104, thereby obtaining at least two optical paths. Among them, the extension unit may include multiple groups of reflectors, and the reflectors are located on the propagation path of the second optical path. The second optical path is folded back between multiple groups of reflectors to extend the second optical path. It should be noted that the specific arrangement between the multiple groups of reflectors can be determined according to actual needs. As an example, in one embodiment, the reflectors can be set in four groups, including a first reflector 901, a second reflector 902, a third reflector 903 and a fourth reflector 904. The first reflector 901 and the second reflector 902 are arranged in parallel, and the reflection surface of the first reflector 901 is arranged opposite to the reflection surface of the second reflector 902. The third reflector 903 and the fourth reflector 904 are arranged in parallel, and the reflection surface of the third reflector 903 is arranged opposite to the reflection surface of the fourth reflector 904. The second reflector 902 and the third reflector 903 are arranged vertically, so the light path passes through the first reflector 901, the second reflector 902, the third reflector 903 and the fourth reflector 904 in sequence to increase the light path.

[0057] Alternatively, see Figure 4As shown, the extension unit may include a beam splitter and multiple groups of plane mirrors. In one embodiment, the plane mirrors are provided with two groups, and the plane mirrors may include a first plane mirror 301 and a second plane mirror 302. The first plane mirror 301 and the second plane mirror 302 are vertically arranged, and the beam splitter is located between the first plane mirror 301 and the second plane mirror 302. Therefore, after the light beam passes through the beam splitter, a part of the light beam is reflected and propagates to the first plane mirror 301. The first plane mirror 301 reflects the light beam and continues to propagate through the beam splitter. Another part of the light beam passes through the beam splitter, is reflected by the second plane mirror 302, is reflected by the beam splitter, and continues to propagate. Therefore, the optical path of the two beams is further increased during the process of returning.

[0058] In summary, the present invention discloses a vehicle-mounted holographic display device, and the holographic display can record the complete light field information for reconstruction and reconstruct the image at any depth. And the wavefront information is divided into two identical paths through the processing module. Since the spacing between the two branches is the same as the eye box range, two identical eye box ranges can be generated at adjacent positions after splitting, so that the total eye box range is magnified to twice the original, thereby improving the actual observation effect. At the same time, by increasing the number of the processing modules, the eye box range is expanded, thereby expanding the visible range of the human eye. Therefore, the present invention effectively overcomes some practical problems in the prior art and has a high utilization value and use significance.

[0059] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A vehicle-mounted holographic display device, characterized in that: include: An image projection device for producing a real image and generating a laser beam; At least one processing module is located on one side of the image projection device, and includes a light splitting unit, wherein the light splitting unit is used to perform light splitting processing on the laser beam and generate a first light path and a second light path; a reflection unit, located at one side of the processing module and receiving the first light path; and An imaging lens is located on the propagation path of the first optical path and the second optical path, and the imaging lens converts a real image into an enlarged virtual image; Wherein, the spectroscopic unit includes a plurality of spectroscopes, and the spectroscopes are semi-transparent mirrors. The optical paths of the first optical path and the second optical path are of the same length, and the first optical path and the second optical path contain the same wavefront information.

2. The vehicle-mounted holographic display device according to claim 1, characterized in that: The image projection device comprises: a light source, a speckle attenuator, a collimator and a spatial light modulator, wherein the light source, the speckle attenuator, the collimator and the spatial light modulator are arranged in sequence.

3. The vehicle-mounted holographic display device according to claim 2, characterized in that: The spectroscope comprises: A first beam splitter is located on the propagation path of the laser beam, and The second beam splitter is located on the propagation path of the laser beam, and the angle between the second beam splitter and the first beam splitter is 45 degrees.

4. The vehicle-mounted holographic display device according to claim 3, characterized in that: The reflection unit comprises a reflector located at one side of the first beam splitter, and the reflector and the second beam splitter are symmetrically arranged along the first beam splitter.

5. The vehicle-mounted holographic display device according to claim 1, characterized in that: A scattering sheet is also included, which is located on one side of the imaging lens, and the light path passes through the scattering sheet.

6. The vehicle-mounted holographic display device according to claim 2, characterized in that: The magnified virtual image formed by the imaging lens is imaged on the outside of the windshield.

7. The vehicle-mounted holographic display device according to claim 6, characterized in that: The area of ​​the enlarged virtual image formed on the windshield is the eye box area, and the size of the eye box area is E. d , expressed as: Among them, k represents the magnification factor, f represents the focal length of the imaging lens, p represents the pixel pitch of the spatial light modulator, N represents the prime number of the spatial light modulator in one-dimensional direction, and u represents the distance between the spatial light modulator and the imaging lens.

8. The vehicle-mounted holographic display device according to claim 7, characterized in that: The positional relationship between the imaging lens, the spatial light modulator and the eye box area is: Among them, f represents the focal length of the imaging lens, u represents the distance between the spatial light modulator and the imaging lens, and v represents the distance between the eye box area and the imaging lens.

9. The vehicle-mounted holographic display device according to claim 1, characterized in that: The processing module further includes an extension unit, wherein the extension unit includes a plurality of reflectors, and the reflectors are located on a propagation path of the second light path.

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