Grating assembly and preparation method thereof, head-up display device and carrier

Abstract

The invention discloses a grating assembly and a preparation method thereof, a head-up display device and a carrier, the grating assembly comprises a light splitting device and an aberration compensation layer, and the light splitting device is used for splitting image light emitted by an imaging unit of head-up display; the aberration compensation layer is located on a light path of the image light after light splitting of the light splitting device, and is used for refracting the image light after light splitting to the windshield and compensating image distortion caused by the surface type of the windshield. The grating assembly provided by the invention can be applied to the head-up display device, firstly, the light splitting device is used for splitting the head-up displayed image light, and then the aberration compensation layer is used for carrying out aberration correction, so that the imaging effect of the head-up display device and the visual experience of a user are improved.

Description

Technical Field

[0001] Embodiments of the present invention relate to the field of display technology, and in particular, to a grating component, a preparation method thereof, a head-up display device, and a vehicle. Background Art

[0002] The naked-eye 3D display technology enables users to perceive a flat two-dimensional picture or video as a three-dimensional stereoscopic effect with the naked eye without the aid of any external devices such as 3D glasses. The naked-eye 3D display technology involves attaching a slit / cylindrical lens grating to a liquid crystal display (LCD). By utilizing the grating technology, the pixels covered under the grating are divided into the pixels viewed by the user's left eye and the pixels viewed by the user's right eye. When the user's left and right eyes view the screen, they will respectively see two sets of pixel points, thereby generating a parallax, and the user can view the information with a 3D display effect.

[0003] Applying the naked-eye 3D display technology to an in-vehicle HUD results in the AR-HUD technology. Existing AR-HUD optical systems generally include at least one imaging unit and multiple optical mirrors, such as plane mirrors, curved mirrors, etc. After the imaging unit emits image light, the light is sequentially adjusted in direction and corrected for aberration by passing through a plane mirror and a curved mirror, and then reflected to the windshield, and finally reflected by the windshield to the eye box. However, due to the fact that the surface shape of the windshield does not conform to the ideal situation, the projected image exhibits display distortion, affecting the display effect, especially having an adverse impact on the naked-eye 3D imaging effect. In addition, the complex optical elements in the existing system increase the system cost, structural volume, and assembly complexity. Summary of the Invention

[0004] The present invention provides a grating component, a preparation method thereof, a head-up display device, and a vehicle. The grating component can be applied to a head-up display device. First, a beam splitter device is used to split the image light, and then an aberration compensation layer is used to correct the aberration, thereby improving the imaging effect of the head-up display device and the user's visual experience.

[0005] In a first aspect, an embodiment of the present invention provides a grating component, which is applied to a head-up display device and includes:

[0006] A beam splitter device, configured to split the image light emitted from the imaging unit of the head-up display;

[0007] An aberration compensation layer, located on the optical path of the image light after being split by the beam splitter device, configured to refract the split image light to the windshield and compensate for the image distortion caused by the windshield surface shape.

[0008] Optionally, the outermost surface shape of the aberration compensation layer is a free-form surface;

[0009] The curvature of any point on the free-form surface is set to compensate for the curvature of the light refracted at the corresponding reflection point on the windshield surface when reaching that point.

[0010] Optionally, the aberration compensation layer is attached to the beam splitting device.

[0011] Optionally, it further includes an intermediate layer that covers the beam splitting device, and the aberration compensation layer covers the intermediate layer;

[0012] The difference between the refractive index of the beam splitting device, the refractive index of the intermediate layer, and the refractive index of the aberration compensation layer is set to compensate for the image distortion caused by the non-coplanarity of multiple reflection points on the windshield.

[0013] Optionally, the beam splitting device includes a cylindrical lens grating, and the cylindrical lens grating includes a plurality of periodically arranged grating structures;

[0014] The aberration compensation layer includes a plurality of array units, and each array unit covers at least one of the grating structures.

[0015] Optionally, the outermost surface profiles of the array units are the same; or, the outermost surface profiles of at least two of the array units are different.

[0016] Optionally, the materials of the beam splitting device and the aberration compensation layer include optical resin.

[0017] Optionally, the refractive indices of both the beam splitting device and the aberration compensation layer are greater than or equal to 1.3.

[0018] Optionally, the beam splitting device and the aberration compensation layer are glued together.

[0019] Based on the same inventive concept, in a second aspect, an embodiment of the present invention further provides a method for manufacturing a grating assembly applied to a head-up display, for manufacturing the grating assembly provided in the first aspect, and the manufacturing method includes:

[0020] Manufacture a beam splitting device for splitting the image light emitted by the imaging unit of the head-up display device;

[0021] Manufacture an aberration compensation layer for refracting the image light to the windshield and compensating for the image distortion caused by the windshield surface profile.

[0022] Optionally, the manufacturing method further includes:

[0023] Attach the aberration compensation layer to the beam splitting device, and set the outermost surface profile of the aberration compensation layer as a free-form surface; the curvature of any point on the free-form surface is set to compensate for the curvature of the light refracted at the corresponding reflection point on the windshield surface when reaching that point.

[0024] Optionally, before preparing the aberration compensation layer, it further includes:

[0025] Prepare an intermediate layer to cover the beam splitter device;

[0026] Prepare an aberration compensation layer to cover the intermediate layer, wherein, based on the image distortion generated by the non-coplanarity of multiple reflection points on the windshield, set the difference between the refractive index of the beam splitter device, the refractive index of the intermediate layer, and the refractive index of the aberration compensation layer; set the outermost surface profile of the aberration compensation layer as a free-form surface; based on the curvature of the light ray refracted at any point on the free-form surface reaching the corresponding reflection point on the windshield surface, set the curvature of the any point on the free-form surface.

[0027] Based on the same inventive concept, in a third aspect, an embodiment of the present invention further provides a head-up display device, including the grating component provided in the first aspect, and further including:

[0028] An imaging unit for emitting image light;

[0029] The grating component is disposed on the optical path of the image light;

[0030] The windshield is disposed on the optical path of the image light after being split by the grating component, and is used for reflecting the image light to the viewing area.

[0031] Based on the same inventive concept, in a fourth aspect, an embodiment of the present invention further provides a vehicle, including the head-up display device provided in the third aspect.

[0032] The grating component provided by the embodiment of the present invention is applied to a head-up display device. On the optical path of the image light emitted by the imaging unit of the head-up display device, only the grating component is used. The head-up display image light is split by a beam splitter device and aberration correction is performed using an aberration compensation layer. Compared with the prior art, there is no need to set a curved mirror before the imaging component. In this way, the number of optical devices on the optical path of the image light can be reduced, the system cost can be reduced. At the same time, since there is no need to configure multiple sets of reflectors, the assembly process of the grating component of the present application is simpler and the cost is lower, which is suitable for mass production. On the other hand, the present application covers the beam splitter device with an aberration compensation layer, which can avoid thermal deformation of the beam splitter device and protect the beam splitter device, and ultimately helps to improve the system stability of the head-up display device. Description of the Drawings

[0033] Figure 1 It is a schematic diagram of a head-up display device provided by the prior art applied in a vehicle;

[0034] Figure 2 It is a schematic structural diagram of a head-up display device provided by an embodiment of the present invention;

[0035] Figure 3It is a schematic structural diagram of a grating component provided by an embodiment of the present invention;

[0036] Figure 4 is Figure 3 a schematic cross-sectional view of a grating component provided;

[0037] Figure 5 is Figure 3 a schematic cross-sectional view of another grating component provided;

[0038] Figure 6 It is a schematic structural diagram of another head-up display device provided by an embodiment of the present invention;

[0039] Figure 7 It is a schematic structural diagram of another grating component provided by an embodiment of the present invention;

[0040] Figure 8 is Figure 7 a schematic cross-sectional view of another grating component provided;

[0041] Figure 9 It is a schematic structural diagram of another head-up display device provided by an embodiment of the present invention;

[0042] Figure 10 is Figure 9 a schematic interface view of a grating component provided;

[0043] Figure 11 It is a schematic structural diagram of another head-up display device provided by an embodiment of the present invention;

[0044] Figure 12 It is a schematic diagram of a head-up display device provided by an embodiment of the present invention applied in a vehicle. Detailed implementation manners

[0045] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. Additionally, it should be noted that for the sake of description, only parts related to the present invention rather than all structures are shown in the drawings.

[0046] Figure 1 It is a schematic diagram of a head-up display device provided by the prior art applied in an automobile, referring to Figure 1, in the prior art, a Head Up Display (HUD) is a driving assistance instrument used in automobiles and is an integrated electronic display device composed of electronic components, a display component, a controller, etc. It can project information such as vehicle speed, navigation information, and warnings in the form of images and characters onto the front of the driver through optical components. The HUD usually emits image light from at least one imaging unit, and at least one plane mirror and one curved mirror are sequentially arranged on the optical path of the image light. After the propagation direction of the image light is adjusted by the plane mirror, it is reflected to the front windshield of the car after aberration correction by the curved mirror, and then reflected by the front windshield to the driver's eyebox range. The driver can see the image displayed by the imaging unit in front of the front windshield. However, in reality, due to non-ideal factors such as the surface shape and thickness of the front windshield, the projected images seen by the left and right eyes will be distorted, such as horizontal stretching, vertical stretching, or local deformation of the image, which will affect the 3D display effect and even driving safety.

[0047] Based on the above technical problems, an embodiment of the present invention provides a grating component that can be applied to a head-up display device. The imaging unit of the head-up display device emits image light, and a grating component is added to the optical path of the image light. First, the image light is split by a beam splitter device, and then aberration correction is performed using an aberration compensation layer, so that the left and right eyes of the user can respectively see virtual images of image light with different emission angles, and the seen images have a three-dimensional sense due to the parallax effect. Figure 2 It is a schematic structural diagram of a head-up display device provided by an embodiment of the present invention. Figure 3 It is a schematic structural diagram of a grating component provided by an embodiment of the present invention. Figure 4 is Figure 3 A cross-sectional schematic diagram of a grating component provided. Figure 5 is Figure 3 Another cross-sectional schematic diagram of the provided grating component, refer to Figures 2 - 5 , the head-up display device provided by the embodiment of the present invention includes an imaging unit 1, a grating component 2, and a windshield 3.

[0048] Refer to Figure 2, the imaging unit 1 includes a display device that can emit image light for emitting image light. For example, the imaging unit 1 can be a liquid crystal display, or an active light-emitting dot matrix screen composed of light-emitting point light sources such as LED (Light-Emitting Diode), OLED (Organic Light-Emitting Diode), and plasma light-emitting dots; it can also be based on projection technologies such as DLP (Digital Light Procession), LCOS (Liguid Crystal on Silicon), and liquid crystal, driven by light sources such as LED, OLED, laser, and fluorescence or combinations thereof, reflected or transmitted through display panels such as DMD (Digital Micromirror Device), LCOS, and LCD, and then projected onto a projection screen through a projection lens for imaging; it can also be a projection imaging device that scans and images a laser beam on a screen. The embodiments of the present invention do not limit the type of the imaging unit 1. It can be understood that in the embodiments of the present invention, the image light S emitted by the imaging unit 1 includes the image light directly emitted by the imaging unit 1, and also includes the light formed after the image light undergoes optical effects such as refraction, reflection, waveguide, and diffraction.

[0049] Among them, in vehicle-mounted applications, the eyebox is the area where the driver's eyes move. The image light S can transmit important system information such as navigation and Bluetooth calls. The windshield 3 can be the front windshield in a vehicle. It should have a high transmittance for visible light to ensure a clear view for the vehicle driver, and also have a certain reflection effect on the image light S emitted by the imaging unit 1, so that the driver can clearly see the system information on the front windshield and avoid safety hazards caused by the driver lowering their head or shifting their line of sight.

[0050] In the embodiments of the present application, a grating assembly 2 is provided on the optical path of the image light emitted by the imaging unit 1. The beam splitter S1 of the grating assembly 2 splits the image light emitted by the imaging unit 1 of the head-up display device into two image lights with different propagation directions. The aberration compensation layer S2 compensates for the aberration of the two split image lights based on the image distortion caused by the windshield surface shape. The two compensated image lights are reflected by the windshield 3 and then respectively incident on the eyebox, so that the user's left eye and right eye can respectively see the virtual images of the image lights with different emission angles, and the stereoscopic effect of the seen image is generated by the parallax effect.

[0051] It should be noted that the aberration compensation layer S2 provided in the embodiments of the present invention compensates for the aberration caused by the windshield 3 reflecting the image light S based on the surface shape parameters of the windshield 3 and other factors to achieve the purpose of aberration correction. Specifically, refer to Figures 3 - 5, the surface shape of the outermost layer S21 of the aberration compensation layer S2 is a free-form surface, and the curvature of any point on the free-form surface is set to compensate for the image distortion caused by the windshield surface of the light refracted at that any point. Exemplarily, before the aberration compensation layer S2 is provided, methods such as Ray Tracing are used to record the virtual image seen at the eyebox after the image light split by the beam splitter device S1 is reflected by the windshield 3, and the virtual image aberration and distortion are determined. By changing the curvature of each point on the free-form surface S21, the propagation direction of the image light can be changed, so that a virtual image without aberration distortion can be seen at the eyebox after the light is reflected by the windshield. Therefore, by adjusting and optimizing the curvature distribution of each point on the free-form surface, precise compensation for the aberration caused by the windshield surface shape can be achieved, the distortion of the projected image can be improved, and the naked-eye 3D imaging effect can be enhanced.

[0052] Based on the above embodiments, referring to Figure 3 and Figure 5 , the aberration compensation layer S2 is attached to the beam splitter device S1. Exemplarily, the aberration compensation layer S2 is adhesively provided with the beam splitter device S1, so that the light loss between the aberration compensation layer S2 and the beam splitter device S1 can be reduced, and the light efficiency can be improved.

[0053] Based on the above embodiments, referring to Figure 4 , the grating assembly 2 further includes an intermediate layer S3, the intermediate layer S3 covers the beam splitter device S1, and the aberration compensation layer S2 covers the intermediate layer S3. The differences between the refractive index of the beam splitter device S1, the refractive index of the intermediate layer S3, and the refractive index of the aberration compensation layer S3 are set to compensate for the image distortion caused by the non-coplanarity of multiple reflection points on the windshield. In the embodiments of the present invention, due to reasons such as the curved surface shape or rough surface of the windshield 3, there are multiple non-coplanar reflection points on the surface of the windshield 3, which results in that even the image light with the same incident angle is reflected by the multiple non-coplanar reflection points, and the light will still generate aberration in the observation area (eyebox), causing image distortion. Based on this, the embodiments of the present invention can also adjust the refractive indices of the optical devices S1, the intermediate layer S3, and the aberration compensation layer S2 stacked in the grating assembly 2, so that the image light changes its propagation direction to reach the windshield 3 after being refracted by the intermediate layer S3 and the multi-aberration compensation layer S2 in sequence, so that the image light converges in the observation area (eyebox) after being reflected by the windshield 3, forming a non-distorted image, thus compensating for the aberration caused by the windshield 3 surface shape in the subsequent optical path, thereby improving the naked-eye 3D effect.

[0054] Based on the above embodiments, referring to Figures 3 - 5 , the beam splitter device S1 includes a lenticular grating, the lenticular grating includes a plurality of periodically arranged grating structures S12, and the aberration compensation layer S2 covers the lenticular grating.

[0055] In the embodiments of the present application, the grating assembly 2 alone can complete the light modulation of the image light S and the aberration correction. Compared with the prior art, there is no need to set a curved mirror in front of the windshield 3, so the number of optical devices on the optical path of the image light S can be reduced, and the system cost can be reduced. At the same time, in the present application, the aberration compensation layer S2 covers the cylindrical lens grating, which can protect the grating structure and prevent the grating structure from being worn.

[0056] Figure 6 FIG. 4 is a schematic structural diagram of another head-up display device provided by an embodiment of the present invention. Figure 7 FIG. 6 is a schematic structural diagram of a grating assembly provided by an embodiment of the present invention. Figure 8 is Figure 7 A cross-sectional schematic diagram of the provided grating assembly, referring to Figures 6 - 8 , the beam splitting device S1 includes a cylindrical lens grating, the cylindrical lens grating includes a plurality of periodically arranged grating structures S12, the aberration compensation layer S2 includes a plurality of array units 222, and the array unit 222 covers at least one grating structure S12. Among them, the outermost surface shape of the array unit 222 is the free-form surface provided in the above embodiment.

[0057] In some embodiments, the outermost surface shapes of the array units 222 are the same. For example, a spherical surface is used, and the refraction effects of the plurality of array units 222 on the image light S are the same. In some embodiments, the outermost surface shapes of at least two array units 222 are different. In some applications, it is necessary to perform differential refraction on the image light S in different regions. The outermost surface S21 of one array unit 222 is set to be spherical, and the outermost surface S21 of one array unit 222 is set to be aspherical. In this way, the aberration correction is performed on the image light corresponding to the two regions respectively. Due to the non-uniformity of the HUD system, such a design can meet the different aberration correction requirements of different regions of the system and reduce image distortion.

[0058] Optionally, referring to Figure 8 , the array unit 222 covers at least one grating structure S12 to realize the aberration correction of the image light emitted by the grating structure S12 alone.

[0059] Figure 9 FIG. 24 is a schematic structural diagram of another head-up display device provided by an embodiment of the present invention. Figure 10 is Figure 9 An interface schematic diagram of a provided grating assembly, referring to Figure 9 and Figure 10 , the outermost layer S21 of the aberration compensation layer S2 is a plane, and its surface records the corresponding phase distribution information according to the shape of the windshield 3 by a photosensitive material. After the image light S is split by the cylindrical lens grating, the light rays at different positions of the aberration compensation layer S2 generate different phase differences.

[0060] See Figure 9 andFigure 10 , an embodiment of the present invention provides another head-up display device structure. In this embodiment, the outermost surface S21 of the aberration compensation layer S2 is designed as a plane, and the phase distribution information corresponding to the shape of the windshield 3 is recorded on the plane surface by a photosensitive material. When the image light S is split by the cylindrical lens grating and passes through different positions of the compensation layer S2, corresponding phase difference changes will occur. Therefore, the phase distribution pattern of the front windshield 3 can be recorded on the outer layer of S2 by using holographic projection technology according to the actual shape of the front windshield 3, so that the plane S21 can introduce corresponding phase compensation when refracting the light, thereby canceling the aberration generated by the windshield. The topography information of the windshield is recorded on the outer surface of the compensation layer by holographic means, so that the compensation layer itself becomes a phase compensation element, and the phase information of the image light is spatially modulated to achieve the purpose of aberration compensation.

[0061] Figure 11 is a schematic structural diagram of another head-up display device provided by an embodiment of the present invention. Refer to Figure 11 , the head-up display device provided by the embodiment of the present application further includes a reflection component 4, which is arranged on the optical path of the image light S between the grating component 2 and the windshield 3, and is used to adjust the propagation direction of the image light S to the windshield 3.

[0062] Refer to Figure 11 , the reflection component 4 includes a first reflector 41 and a second reflector 42, and the first reflector 41 and the second reflector 42 are arranged opposite to each other. The grating component 2 can be any one of the structures provided in the above embodiments, and is arranged on the optical path of the image light emitted by the imaging unit 1. After the image light S is adjusted in light and aberration corrected by the grating component 2, it is reflected by the first reflector 41 and the second reflector 42 and then reaches the windshield 3. The first reflector 41 is a plane mirror, which has a reflection effect on the image light and is used to adjust the propagation direction of the image light S. The second reflector 42 is a curved mirror, which is used to adjust the spatial distribution of the image light. It can be understood that in the embodiment of the present invention, the spatial distribution of the image light can be jointly adjusted by the grating component and the second reflector 42, which can reduce the assembly accuracy requirements of the reflection component.

[0063] Optionally, refer to Figures 2 - 11 , the refractive indices of both the cylindrical lens grating and the aberration compensation layer S2 are greater than or equal to 1.3. Selecting materials with a higher refractive index is beneficial to generating a large refraction in the compensation layer to produce the required aberration compensation effect. Among them, the refractive indices of the two can be the same or different, and the embodiments of the present application do not make any restrictions and can be adjusted according to design requirements.

[0064] Optionally, refer to Figures 2 - 11 , the materials of the cylindrical lens grating and the aberration compensation layer S2 include optical resin. The cylindrical lens grating and the aberration compensation layer S2 are glued and fixed, and the structure is integrally formed, which can reduce the assembly process.

[0065] Optionally, referring to Figure 4 , Figure 7 , Figure 8 and Figure 10 , the grating assembly 2 further includes an intermediate layer S3, the intermediate layer S3 covers the lenticular grating, and the aberration compensation layer S2 covers the intermediate layer S3. The intermediate layer S3 is used to fill the lenticular grating, and the bottom surface S22 of the aberration compensation layer S2 can be a plane. The materials of the lenticular grating, the intermediate layer S3, and the aberration compensation layer S2 are all optical resins with good light transmittance, and the refractive indices of the three are all greater than 1.3. Among them, the refractive indices of the three can be the same or different, and the difference between the refractive index of the light splitting device, the refractive index of the intermediate layer, and the refractive index of the aberration compensation layer is set to compensate for the image distortion caused by the non-coplanarity of multiple reflection points on the windshield, which can be adjusted according to design requirements and is not limited in the embodiments of the present application.

[0066] In summary, the head-up display device provided by the embodiments of the present application, by setting any one of the grating assemblies provided in the above embodiments on the image optical path, first uses the light splitting device to split the image light, and then uses the aberration compensation layer to compensate for the aberration of the rear-end optical path, improving the problem of image distortion. At the same time, the number of curved mirrors can be reduced, and the volume and cost of the device can be reduced. The structural design has high flexibility, and the image quality is better than that of traditional HUDs, improving the stereoscopic vision imaging effect and the user's visual experience.

[0067] Based on the same inventive concept, the embodiments of the present application also provide a preparation method for a grating assembly, which is used to prepare the grating assembly provided in the above embodiments. The preparation method includes:

[0068] S101. Prepare a light splitting device for splitting the image light emitted by the imaging unit of the head-up display device.

[0069] S102. Prepare an aberration compensation layer for refracting the image light to the windshield and compensating for the image distortion caused by the windshield surface shape.

[0070] Specifically, referring to Figures 3 - 5 , the light splitting device S1 can adopt a lenticular grating to split the image light emitted by the imaging unit of the head-up display device. Based on the characteristics of the windshield surface shape, the aberration compensation layer S2 is attached to the light splitting device S1, and the outermost surface shape of the aberration compensation layer S2 is set as a free-form surface.

[0071] Among them, the curvature of any point on the free-form surface is set to compensate for the curvature of the light ray refracted by the any point reaching the corresponding reflection point on the windshield surface.

[0072] Specifically, referring to Figures 3 - 5 , the light splitting device S1 can adopt a lenticular grating to split the image light emitted by the imaging unit of the head-up display device. Prepare an intermediate layer S2 to cover the lenticular grating, and prepare an aberration compensation layer S3 to cover the intermediate layer S2.

[0073] Among them, the differences between the refractive index of the beam splitting device, the refractive index of the intermediate layer, and the refractive index of the aberration compensation layer are set based on the image distortion generated by the non-coplanarity of multiple reflection points on the windshield. At the same time, the outermost surface shape of the aberration compensation layer is set as a free-form surface, and the curvature of any point on the free-form surface is set based on the curvature of the light ray refracted at any point on the free-form surface reaching the corresponding reflection point on the windshield surface.

[0074] The grating assembly 2 obtained in this way can complete the light modulation of the image light S and aberration correction of the head-up display device. In this application, covering the cylindrical grating with the aberration compensation layer S2 or the intermediate layer S3 can play a role in protecting the grating structure and avoiding wear of the grating structure.

[0075] Based on the same inventive concept, the embodiment of this application also provides a vehicle. Figure 12 It is a schematic diagram of a head-up display device provided by an embodiment of the present invention applied in a vehicle. As Figure 12 shown, the head-up display device HUD is assembled in the vehicle and also has the beneficial effects of the head-up display device HUD in the above-mentioned implementation manner. When the vehicle is an automobile, the imaging component is the front windshield, and the user sees a virtual image at the image plane through the front windshield. The same parts can be understood with reference to the above explanation of the head-up display device HUD, and will not be elaborated below.

[0076] Note that the above is only the preferred embodiment of this application and the applied technical principle. Those skilled in the art will understand that this application is not limited to the specific embodiments described here. Various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of this application. Therefore, although this application has been described in more detail through the above embodiments, this application is not limited to the above embodiments. Without departing from the concept of this application, it can also include more other equivalent embodiments, and the scope of this application is determined by the scope of the appended claims.

Claims

1. A grating component, which is applied to a head-up display device, and is characterized in that, Comprising: A beam splitting device for splitting the image light emitted by the imaging unit of the head-up display device; An aberration compensation layer located on the optical path of the image light after splitting by the beam splitting device, for refracting the split image light to the windshield and compensating for the image distortion caused by the windshield surface shape.

2. The grating component according to claim 1, characterized in that, The outermost surface shape of the aberration compensation layer is a free-form surface; The curvature of any point on the free-form surface is set to compensate for the curvature of the light ray refracted at the corresponding reflection point on the windshield surface when reaching that point.

3. The grating assembly according to claim 2, wherein The aberration compensation layer is attached to the beam splitting device.

4. The grating component according to claim 2, characterized in that, It further includes an intermediate layer that covers the beam splitting device, and the aberration compensation layer covers the intermediate layer; The difference between the refractive index of the beam splitting device, the refractive index of the intermediate layer, and the refractive index of the aberration compensation layer is set to compensate for the image distortion caused by the non-coplanarity of multiple reflection points on the windshield.

5. The grating component according to claim 1, characterized in that, The beam splitting device includes a cylindrical lens grating, and the cylindrical lens grating includes a plurality of periodically arranged grating structures; The aberration compensation layer includes a plurality of array units, and each array unit at least covers one of the grating structures.

6. The grating component according to claim 5, characterized in that, The outermost surface shapes of the array units are the same; or, the outermost surface shapes of at least two of the array units are different.

7. The grating component according to claim 1, characterized in that, The materials of the beam splitting device and the aberration compensation layer include optical resin.

8. The grating component according to claim 7, characterized in that The refractive indices of the beam splitting device and the aberration compensation layer are both greater than or equal to 1.

3.

9. The grating component according to claim 1, wherein The beam splitting device and the aberration compensation layer are glued together.

10. A method for preparing a grating assembly, which is used to prepare the grating assembly according to any one of claims 1-9, characterized in that, The preparation method includes: Preparing a beam splitting device for splitting the image light emitted by the imaging unit of the head-up display device; Preparing an aberration compensation layer for refracting the image light to the windshield and compensating for the image distortion caused by the windshield surface shape.

11. The preparation method according to claim 10, characterized in that, The preparation method further includes: Attaching the aberration compensation layer to the beam splitting device, and setting the outermost surface shape of the aberration compensation layer as a free-form surface; the curvature of any point on the free-form surface is set to compensate for the curvature of the light ray refracted at the corresponding reflection point on the windshield surface when reaching that point.

12. The preparation method according to claim 10, characterized in that, Before preparing the aberration compensation layer, it further includes: Preparing an intermediate layer to cover the beam splitting device; Preparing an aberration compensation layer to cover the intermediate layer, wherein the difference between the refractive index of the beam splitting device, the refractive index of the intermediate layer, and the refractive index of the aberration compensation layer is set based on the image distortion caused by the non-coplanarity of multiple reflection points on the windshield; setting the outermost surface shape of the aberration compensation layer as a free-form surface; setting the curvature of any point on the free-form surface based on the curvature of the light ray refracted at that point when reaching the corresponding reflection point on the windshield surface.

13. A head-up display device, characterized in that, Including the grating assembly according to any one of claims 1-9, and further including: An imaging unit for emitting image light; The grating assembly is disposed on the optical path of the image light; The windshield is disposed on the optical path of the image light after splitting by the grating assembly, for reflecting the image light to the viewing area.

14. A vehicle, characterized in that, Including the head-up display device according to claim 13.

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