AR display module, vehicle-mounted AR display device and vehicle

Abstract

This application discloses an AR display module, an AR display device, and a vehicle, belonging to the field of vehicle-mounted equipment technology. The AR display module includes: a light-emitting unit, a display and imaging unit, an optical path coupling unit, and an optical waveguide unit; wherein, the optical path coupling unit includes a triangular prism and a mirror assembly; the triangular prism includes a first optical surface, a second optical surface, and a third optical surface connected end-to-end, the first optical surface facing the emitting end of the display and imaging unit, the second optical surface facing the incident end of the optical waveguide unit, and the third optical surface facing the reflecting surface of the mirror assembly; a first polarization beam-splitting film is formed on the second optical surface; a quarter-wave plate structure is integrated into the mirror assembly. By using the triangular prism and the mirror assembly to filter the polarization state and fold the optical path of the image light, the image light can be efficiently coupled into the waveguide at an angle that meets the requirements of optical waveguide transmission, while improving the system's light utilization and integration.

Description

Technical Field

[0001] This application relates to the field of vehicle-mounted equipment technology, and in particular to an AR display module, a vehicle-mounted AR display device, and a vehicle. Background Technology

[0002] Augmented reality (AR) technology refers to the fusion and overlay of virtual information with real-world scenes, enabling users to intuitively obtain enhanced information while observing their real-world environment. With the continuous development of vehicle intelligence and smart cockpits, AR technology has been widely applied and upgraded in the field of in-vehicle interaction, becoming a revolutionary technology for in-vehicle display products such as head-up displays and AR glasses.

[0003] In related technologies, the core of AR display devices—the AR display module—usually includes the following components: light source, display chip, optical transmission components, and optical coupling components. The light-emitting unit provides illumination, the display chip generates images, and the optical transmission and coupling components shape and transmit the light beam, ultimately forming an augmented reality image on the human eye or projection surface.

[0004] However, traditional AR display solutions typically require long optical paths and complex optical transmission structures, resulting in large system size issues for AR display modules while ensuring display effects such as large field of view and long-distance imaging. Summary of the Invention

[0005] This application provides an AR display module, an in-vehicle AR display device, and a vehicle to solve the technical problems existing in related technologies. Specifically, it includes the following technical solutions.

[0006] In a first aspect, this application provides an AR display module, comprising: a light-emitting unit for emitting illumination light; a display and imaging unit for modulating the illumination light according to image information to obtain image light carrying the image information; an optical path coupling unit for coupling the image light into the incident end of an optical waveguide unit; the optical waveguide unit for guiding the image light to an eye-box region; wherein the optical path coupling unit includes a triangular prism and a reflector group; the triangular prism includes a first optical surface, a second optical surface, and a third optical surface connected in pairs and end-to-end, the first optical surface being opposite to the emitting end of the display and imaging unit, the second optical surface being opposite to the incident end of the optical waveguide unit, and the third optical surface being opposite to the reflecting surface of the reflector group; a first polarization beam-splitting film is formed on the second optical surface, the first polarization beam-splitting film being used to filter the polarization state of light passing through the triangular prism from the third optical surface; a quarter-wave plate structure is integrated in the reflector group, the quarter-wave plate structure being located between the reflecting surface and the third optical surface.

[0007] In some possible implementations, the reflecting surface is a freeform surface structure, and the surface parameters of the freeform surface structure are determined based on the incident range and critical angle of the incident end of the optical waveguide unit.

[0008] In some possible implementations, the optical waveguide unit adopts an array waveguide structure, which includes multiple sub-optical waveguide units arranged in parallel along the propagation direction of the image light.

[0009] In some possible implementations, the light-emitting unit includes a light source for emitting the illumination light; the light-emitting unit also includes a collimating lens group for reducing the divergence angle of the illumination light.

[0010] In some possible implementations, the display and imaging unit includes a display chip and a diffusion display unit; the display chip is used to receive illumination light and modulate the illumination light according to the image information to obtain a modulated beam carrying the image information; the diffusion display unit is used to homogenize and diffuse the modulated beam.

[0011] In some possible implementations, the display and imaging unit further includes an imaging lens group; the imaging lens group is used to perform imaging correction and angle modulation on the homogenized and diffused modulated beam output by the diffusion display unit to obtain the image light; and to transmit the image light through the emitting end of the display and imaging unit to the first optical surface.

[0012] In some possible implementations, the AR display module further includes an ambient light detection unit; the ambient light detection unit is located at the emitting end of the optical waveguide unit and is used to detect the intensity of ambient light; the light-emitting unit is also used to adjust the brightness of the illumination light according to the intensity of the light.

[0013] In some possible implementations, a heat dissipation component is integrated into the light-emitting unit and / or the display and imaging unit, the heat dissipation component being used to perform a heat dissipation operation when the temperature of the light-emitting unit and / or the display and imaging unit reaches a first temperature threshold.

[0014] Secondly, this application provides an in-vehicle AR display device, which includes the AR display module described in any possible embodiment of the first aspect of this application.

[0015] Thirdly, this application provides a vehicle equipped with the in-vehicle AR display device described in the second aspect of this application.

[0016] The beneficial effects of the technical solution provided in this application include at least the following: The technical solution provided in this application features a special design for the optical path coupling unit in the AR display module. By using a triangular prism and a reflector group to filter the polarization state of the image light in the optical path and fold the optical path, the image light can be efficiently coupled into the waveguide at an angle that meets the requirements for waveguide transmission, while simultaneously improving the system's light utilization and integration. Specifically, the triangular prism group includes a first optical surface, a second optical surface, and a third optical surface, which are respectively opposite to the display and imaging unit, the optical waveguide unit, and the reflector group. A quarter-wave plate structure is provided between the reflector surface and the third optical surface of the reflector group, so that the image light undergoes polarization state rotation after passing through the quarter-wave plate, distinguishing it from the incident polarization state. This allows for effective separation by the polarization structure without backtracking, thereby achieving unidirectional optical path transmission, reducing stray light interference, and improving the contrast and imaging clarity of the AR display. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of an AR display module provided in an embodiment of this application; Figure 2 This is a schematic diagram of another AR display module provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of another AR display module provided in the embodiments of this application.

[0019] Explanation of reference numerals in the attached figures: 110. Light-emitting unit; 120. Display and imaging unit; 130. Optical path coupling unit; 140. Optical waveguide unit; 150. Eye box area; 160. Ambient light detection unit; 170. PBS; 111. Light source; 112. Collimating lens group; 121. Display chip; 122. Diffusion display unit; 123. Imaging lens assembly; 131. Triangular prism; 132. Mirror assembly; 131-1. First optical surface; 131-2. Second optical surface; 131-3. Third optical surface; 132-1. Reflecting surface. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0022] In the field of vehicle intelligence or smart cockpits, the limited space in vehicle cabins, coupled with the requirement for AR display devices to have a wide field of view, long virtual image distance, and high real-scene fusion display effect, results in traditional AR display devices, when applied to vehicle intelligence or smart cockpits, often having a large system size for their core module—the AR display module. For example, for AR-HUD (Head-Up Display), to achieve long-distance virtual images and large-format displays, traditional solutions typically require a long optical imaging path to transmit the image to the light path and project it onto the windshield. This leads to problems such as a large overall structure and low light efficiency, making it difficult to adapt to the layout requirements of the confined space of the cockpit.

[0023] In view of this, this application provides an AR display module, which includes a light-emitting unit, a display and imaging unit, an optical path coupling unit, and an optical waveguide unit that are optically connected to each other; the light-emitting unit is used to emit illumination light; the display and imaging unit is used to modulate the illumination light according to image information to obtain image light carrying image information; the optical path coupling unit is used to couple the image light into the incident end of the optical waveguide unit; the optical waveguide unit is used to guide the image light to the eye box area.

[0024] The optical path coupling unit includes a triangular prism and a mirror assembly. The triangular prism includes a first optical surface, a second optical surface, and a third optical surface that are connected in pairs and end to end. The first optical surface is opposite to the output end of the display and imaging unit, the second optical surface is opposite to the input end of the optical waveguide unit, and the third optical surface is opposite to the reflecting surface of the mirror assembly. A first polarization beam splitter is formed on the second optical surface. The first polarization beam splitter is used to filter the polarization state of the light passing through the triangular prism from the third optical surface. A quarter-wave plate structure is integrated in the mirror assembly. The quarter-wave plate structure is located between the reflecting surface and the third optical surface.

[0025] The following will combine Figure 1 The AR display module provided in the embodiments of this application will be further described.

[0026] Figure 1 This is a schematic diagram of the structure of an AR display module provided in an embodiment of this application. Figure 1 As shown, the AR display module includes a light-emitting unit 110, a display and imaging unit 120, an optical path coupling unit 130, and an optical waveguide unit 140. The light-emitting unit 110 includes a light source 111 and a collimating lens group 112; the display and imaging unit 120 includes a first display chip 121, a second display chip 122, and an imaging lens group 123; the optical path coupling unit 130 includes a triangular prism 131 and a reflector group 132, and the triangular prism includes a first optical surface 131-1, a second optical surface 131-2, and a third optical surface 131-3.

[0027] The light-emitting unit 110, the display and imaging unit 120, the optical path coupling unit 130 and the optical waveguide unit are connected by an optical path, that is, the illumination light emitted by the light-emitting unit 110 can pass through the display and imaging unit 120, the optical path coupling unit 130 and the optical waveguide unit 140 in sequence and propagate within them. The components are arranged in sequence along the optical path direction and the beams can be transmitted to each other to form a continuous and complete imaging optical path.

[0028] The light-emitting unit 110 is used, but is not limited to, emitting illumination light.

[0029] Optionally, the illumination light emitted by the light-emitting unit 110 may be, for example, non-parallel light. In this case, the light-emitting unit 110 may include, for example, a light source 111 for emitting illumination light; the light-emitting unit 110 may also include, for example, a collimating lens group 112 for reducing the divergence angle of the illumination light. The divergence angle indicates the degree of diffusion of the illumination light emitted by the light-emitting unit 111. A larger divergence angle results in more dispersed illumination light, lower light intensity, and lower light utilization; a smaller divergence angle results in more parallel illumination light, more concentrated light intensity, and higher light utilization.

[0030] In some embodiments, the light source 111 is, for example, a blue LED (light emitting diode) light source (peak brightness ≥100,000 nits) to make the brightness range of the illumination light emitted by the light source 111 wider, which is beneficial to meet the display brightness requirements in strong light environments, while the brightness can be reduced in low light environments to improve display comfort.

[0031] In other embodiments, the collimating lens group 112 may consist of a set of lenses, which have a biconvex structure and are made of materials such as silicate optical glass. The radii of curvature of the lenses are R1 = 20 mm and R2 = 30 mm. The lenses reduce the divergence angle of the light source 111, greatly improving the light energy utilization rate. Optionally, the lenses in the collimating lens group 112 may have a freeform surface structure. The surface parameters of the freeform surface structure can be set according to the needs of the actual application scenario, and this application does not impose any limitations in this regard.

[0032] Alternatively, the light emitted by the light-emitting unit 110 may be parallel light. In this case, the light-emitting unit 110 may include a light source 111, which may be a laser light source or any other type of light source capable of emitting parallel light.

[0033] In other embodiments, the light source 111 emits illumination light in a manner such as sequential color mixing. For example, when the light source 111 is a blue LED light source, red light and green light can be excited sequentially through a fluorescent color wheel to achieve RGB sequential color mixing illumination. Alternatively, the light source 111 emits illumination light in a manner such as synchronous color mixing illumination. For example, when the light source 111 is a blue LED light source, white light can be emitted by simultaneously exciting RGB three-color light through an integrated fluorescent layer. This application does not impose any limitations in this regard.

[0034] The display and imaging unit 120 is used to modulate the illumination light according to the image information to obtain image light carrying the image information.

[0035] For example, the illumination light is modulated according to the image information. That is, the display and imaging unit 120 adjusts the amplitude, phase, or polarization state of the illumination light according to the brightness, color, and other content of each pixel in the image information, so that the emitted light carries the brightness distribution and color information corresponding to the image information, thereby forming image light that can be used for imaging. The display and imaging unit 120 communicates with the vehicle system, for example, via wired or wireless means. In this case, the image information may be navigation information, instrument information, warning information, AR real-scene fusion image information, etc., sent by the vehicle system. This application does not impose any limitations in this regard.

[0036] In some embodiments, the display and imaging unit 120 includes, for example, a display chip 121 and a diffused display unit 122. The display chip 121 receives illumination light and modulates the illumination light according to image information to obtain a modulated beam carrying image information. For example, it spatially modulates the intensity and polarization state of the illumination light according to the input image information to form a modulated beam carrying image information. The diffused display unit 122, also known as a diffuser, is used to homogenize and diffuse the modulated beam. For example, it eliminates local bright spots and brightness unevenness in the modulated beam, making the light intensity distribution of the output beam from the diffused display unit 122 uniform on the imaging surface, with soft light and no glare, thereby improving the visual quality and comfort of the imaging display.

[0037] Considering that image information is often complex in practical applications, when the display chip 121 modulates the illumination light based on the image information, it is prone to problems such as mutual constraints between brightness and color control, insufficient modulation accuracy, and low light efficiency. For example, simultaneously implementing brightness distribution modulation and color modulation on the same display chip can easily lead to color crosstalk, decreased contrast, and may require color filters, further causing light energy loss. Therefore, the modulation function of the display chip 121 is split according to the image information, allowing different display chips to modulate the image information step by step. This improves control accuracy, reduces image distortion during modulation, increases light efficiency, and simultaneously enhances display quality and system integration.

[0038] In some embodiments, the image information includes, for example, brightness distribution information and non-brightness distribution information. In this case, the display chip 121 includes a first display chip 121 and a second display chip 122. The first display chip 121 is used, but not limited to, modulating the illumination light according to the brightness distribution information, and the second display chip 122 is used, but not limited to, modulating the illumination light according to the non-brightness distribution information. The brightness distribution information is used to indicate the brightness, grayscale, and contrast information of each pixel in the image corresponding to the image information; the non-brightness distribution information is used to indicate information such as color, chroma, saturation, contour, texture, and AR overlay content in the image, excluding brightness distribution.

[0039] As mentioned above, the illumination light emitted by the light source 111 can be either time-mixed or synchronously mixed. Since different illumination methods produce different illumination light, the modulation requirements also differ, leading to different structures for the display and imaging unit 120. For example, if the display and imaging unit 120 includes a first display chip 121 and a second display chip 122, and the illumination method of the light source 111 is time-mixed, then there is one first display chip 121 and one second display chip 122.

[0040] If the illumination method of the light source 11 is synchronous color mixing, then the first display chip 121 includes multiple first sub-display chips. The incident end of any one of the multiple first sub-display chips is provided with a color filter structure for filtering and separating the color of the illumination light, so that any one sub-display chip modulates the corresponding single primary color component in the illumination light according to the brightness distribution information. The second display chip 122 includes multiple second sub-display chips. The incident end of any one of the multiple second sub-display chips is provided with a color filter structure for filtering and separating the color of the illumination light, so that any two sub-display chips modulate the corresponding single primary color component in the illumination light according to the non-brightness distribution information. The number of multiple first sub-display chips and the number of multiple second sub-display chips are related to the number of primary color components of the illumination light. For example, if the primary colors of the illumination light are red, green, and blue, then the number of first and second sub-display chips is 3.

[0041] It is understood that the above-described division of image information and the breakdown of the modulation function of the display and imaging unit 120 according to different image information are illustrative and not restrictive. In some possible cases, the classification method of image information may also include, for example, the division of the image information according to the region of the image, such as the image information including the image center region information and the image edge region information; or, the division according to the content type of the image, such as the image information including text information, icon information, etc.; or, the division according to the optical characteristics of the image information, such as the image information including high brightness region information, low brightness region information, high contrast region information, low contrast region information, etc.; or, the division according to the imaging requirements of the image information, such as the image information including high resolution region information, low resolution region information, etc.

[0042] Based on this, the modulation function in the display and imaging unit 120 can be split according to the method of dividing image information in the actual application scenario, that is, different types of display chips can be configured according to the type of image information. For example, when the image information includes multiple sub-image information of different types, the display and imaging unit 120 includes multiple display chips, each corresponding to a different sub-image information, and each chip is used to modulate the illumination light according to the corresponding sub-image information. The multiple sub-image information can be selected from one or more of the following: image center area information, image edge area information, text information, icon information, high-brightness area information, low-brightness area information, high-contrast area information, low-contrast area information, high-resolution area information, low-resolution area information, etc., or any type of sub-image information divided according to other division criteria. This application does not impose any restrictions in this regard.

[0043] In some embodiments, the display chip 121 is, for example, an LCoS (liquid crystal on silicon) chip. Since LCoS chips have a selective response to the polarization state of light, in some embodiments, when the display chip 121 is an LCoS chip, a PBS (polarizing beamsplitter) is also provided at the incident end of the display and imaging unit 120 to filter and regulate the polarization state of the illumination light, ensuring that the illumination light entering the display chip 121 is illumination light with a single polarization state.

[0044] Figure 2 This is a schematic diagram of another AR display module provided in the embodiments of this application.

[0045] like Figure 2 As shown, when the display chip is an LCoS chip, the AR display module also includes a PBS170. The PBS170 is disposed in the optical path between the incident end of the display and imaging unit 120 and the light-emitting unit 110, and the light-emitting unit 110, PBS170, and display and imaging unit 120 are on the same optical axis. When the illumination light emitted by the light-emitting unit 110 enters the PBS170, the second polarization beam splitter in the PBS170 filters the polarization state of the illumination light. For example, the P-polarized illumination light is transmitted through the PBS170; the S-polarized illumination light is reflected. Then, the P-polarized illumination light transmitted through the PBS170 reaches the LCoS display chip 121, and after being modulated by the LCoS display chip 121, it becomes a modulated beam of S-polarized state carrying image information. Then, the modulated beam of S-polarized state carrying image information re-enters the PBS170, is reflected by the second polarization beam splitter in the PBS170, enters the diffused display unit 122 for propagation, and the subsequent optical path is... Figure 1 The same applies, so I will not repeat it here.

[0046] Figure 3 This is a schematic diagram of the structure of another AR display module provided in the embodiments of this application.

[0047] like Figure 3 As shown, when the display chip is an LCoS chip, the AR display module also includes a PBS170. The PBS170 is also positioned in the optical path between the incident end of the display and imaging unit 120 and the light-emitting unit 110, and the display and imaging unit 120, PBS170, and triangular prism 130 are on the same optical axis. When the illumination light emitted by the light-emitting unit 110 enters the PBS170, the second polarization beam splitter in the PBS170 filters the polarization state of the illumination light. For example, P-polarized illumination light is transmitted through the PBS170; S-polarized illumination light is reflected to the LCoS display chip 121. Then, the S-polarized illumination light reflected to the LCoS display chip 121 is modulated by the LCoS display chip 121 and becomes a P-polarized modulated beam carrying image information. Then, the P-polarized modulated beam carrying image information re-enters the PBS170, transmits through the PBS170, enters the diffusion display unit 122 for propagation, and the subsequent optical path... Figure 1 The same applies, so I will not repeat it here.

[0048] Optionally, the LCoS chip may employ a 0.45-inch silicon-based liquid crystal microdisplay panel with a resolution of at least 1920×1080 and a pixel size of at least 4.5μm. The driving circuit of the LCoS chip may use a MIPI interface and have a refresh rate of at least 60Hz.

[0049] When the display chip 121 includes a first display chip and a second display chip, the first display chip is, for example, an LCoS (liquid crystal on silicon) chip, and the second display chip is, for example, a DLP (Digital Light Processing) chip, an OLED (Organic Light-Emitting Diode) display chip, or another LCoS chip. Wherein, if the first display chip (LCoS chip) is responsible for modulating brightness and darkness distribution information, then the second display chip is responsible for modulating non-brightness and darkness distribution information (such as color, outline, and AR overlay information). The two work together to achieve precise, multi-dimensional modulation of image information, improving display quality and light efficiency. This application does not impose any restrictions on the specific types of the first and second display chips; they can be flexibly selected according to actual modulation requirements.

[0050] In other embodiments, the display and imaging unit 120 may further include an imaging lens group; the imaging lens group is used to perform imaging correction and angle modulation on the modulated beam output by the diffusion display unit 122 after homogenization and diffusion processing to obtain image light; and to transmit the image light through the emitting end of the display and imaging unit to the first optical surface.

[0051] The optical path coupling unit 130 is used, but is not limited to, coupling image light into the incident end of the optical waveguide unit.

[0052] For example, the optical path coupling unit 130 includes a triangular prism 131 and a mirror group 132. The triangular prism 131 includes, for example, a first optical surface 131-1, a second optical surface 131-2, and a third optical surface 131-3 that are connected in pairs and end to end. The first optical surface 131-1 is opposite to the emitting end of the display and imaging unit 120, the second optical surface 131-2 is opposite to the emitting end of the optical waveguide unit 140, and the third optical surface 131-3 is opposite to the reflecting surface of the mirror group.

[0053] A first polarization beam splitter is formed on the second optical surface 131-2. The first polarization beam splitter is used to filter the polarization state of the image light exiting the triangular prism through the third optical surface. For example, if the image light includes P-polarized image light and S-polarized image light, when the image light passes through the first optical surface 131-1 and reaches the second optical surface 131-2, the first polarization beam splitter is used to make the P-polarized image light transmit and the S-polarized image light reflect; or, to make the S-polarized image light transmit and the P-polarized image light reflect.

[0054] The mirror assembly 132 integrates a quarter-wave plate structure located between the reflecting surface 132-1 and the third optical surface 131-3. This quarter-wave plate structure is used, but is not limited to, to filter and regulate the polarization state of the image light between the reflecting surface and the third optical surface 131-3. For example, P-polarized image light reflected by the first polarization beam splitter on the second optical surface 131-2 is reflected to the third optical surface 131-3. After passing through the third optical surface 131-3 and the quarter-wave plate structure, it reaches the reflecting surface 132-1. Reflected by the reflecting surface 132-1, it again passes through the quarter-wave plate structure and the third optical surface 131-3 to reach the second optical surface 131-2. During this process, the P-polarized image light passes through the quarter-wave plate structure twice, becoming S-polarized image light, which then passes through the third optical surface 131-3 and enters the incident end of the optical waveguide unit 140.

[0055] Alternatively, the S-polarized image light, after being reflected by the first polarization beam splitter on the second optical surface 131-2, is reflected to the third optical surface 131-3. After passing through the third optical surface 131-3 and the quarter-wave plate structure in sequence, it reaches the reflecting surface 132-1. After being reflected by the reflecting surface 132-1, it passes through the quarter-wave plate structure and the third optical surface 131-3 again in sequence to reach the second optical surface 131-2. During this process, the S-polarized image light passes through the quarter-wave plate structure twice and becomes the P-polarized image light, which then passes through the third optical surface 131-3 and enters the incident end of the optical waveguide unit 140.

[0056] In some embodiments, the reflecting surface 132-1 of the reflector assembly 132 is a freeform surface structure. The surface parameters of the freeform surface structure of the reflecting surface 132-1 are determined based on the incident range and critical angle of the incident end of the optical waveguide unit 140, so as to better couple the image light reflected by the reflecting surface to the incident end of the optical waveguide unit 140. The surface parameters include, for example, radius of curvature, surface shape coefficient, tilt angle, eccentricity, etc., and this application does not impose any limitations in this regard. The principle for determining the surface parameters based on the incident range and critical angle of the incident end of the optical waveguide unit 140 is: to ensure that the incident angle of the image light reflected by the reflecting surface 132-1 when it reaches the incident end of the optical waveguide unit 140 is less than the critical angle of the optical waveguide unit 140.

[0057] For example, the illumination light emitted by the light source 111 is collimated by the collimating lens group 112, enters the first display chip 121, is modulated by the second display chip 121, and then is imaged by the imaging lens group 123 to obtain the image light. Image light enters the triangular prism 131 through the first optical surface 131-1. After reaching the second optical surface 131-2, it is filtered by the first polarization beam splitter. For example, the image light in the S-polarized state is transmitted through the second optical surface 131-2 and exits the triangular prism 131. The image light in the P-polarized state is reflected and reaches the reflecting surface 132-1 of the mirror group 132 through the third optical surface 131-3. After being reflected by the reflecting surface 132-1, the image light in the P-polarized state passes through the third optical surface 131-3 and enters the triangular prism 131 to reach the second optical surface 131-2. At this time, since the mirror group 132 integrates a quarter-wave plate function, the polarization state of the P-polarized image light becomes the S-polarized state. The image light in the S-polarized state is transmitted through the third optical surface 131-3 and enters the incident end of the optical waveguide unit 140. It then propagates through the optical waveguide unit 140 and enters the eye box region 150.

[0058] In some embodiments, the first polarizing beam splitter film employs, for example, multilayer dielectric film technology, with a polarization extinction ratio greater than 100:1. The quarter-wave plate structure employs, for example, a polymer liquid crystal material, with an operating wavelength range covering, for example, 450 nm–650 nm.

[0059] Optical waveguide unit 140 is used to guide image light to eyebox region 150.

[0060] For example, the optical waveguide unit 140 may employ an arrayed waveguide structure, which includes multiple sub-optical waveguide units arranged parallel to each other along the propagation direction of the image light. The eyebox region 50 is used to indicate the effective visual area where the human eye can observe a complete and clear image, and can be configured according to the needs of the actual application scenario.

[0061] Optionally, the AR display module also includes an ambient light detection unit 160; the ambient light detection unit 160 is located at the emitting end of the optical waveguide unit and is used to detect the light intensity of the ambient light; the light-emitting unit 110 is also used to adjust the brightness of the illumination light according to the light intensity.

[0062] Optionally, the AR display module further includes a temperature detection unit. This unit limits the brightness of the illumination light emitted by the light-emitting unit 110 when the temperature of the light-emitting unit 110 and / or the display and imaging unit 120 reaches a second temperature threshold, to prevent overheating damage to the functional units in the AR display module. The value of the second temperature threshold can be adjusted according to the actual application scenario, for example, set to 0℃, 10℃, 30℃, etc. This application does not impose any restrictions in this regard. Optionally, a heat dissipation component is integrated into the light-emitting unit and / or the display and imaging unit. The heat dissipation component is used to perform heat dissipation operation when the temperature of the light-emitting unit and / or the display and imaging unit reaches a first temperature threshold. The value of the first temperature threshold can be adjusted according to the actual application scenario, for example, it can be set to 0℃, 10℃, 30℃, etc., and this application does not impose any restrictions in this regard.

[0063] The technical solution provided in this application features a special design for the optical path coupling unit in the AR display module. By using a triangular prism and a reflector group to filter the polarization state of the image light in the optical path and fold the optical path, the image light can be efficiently coupled into the waveguide at an angle that meets the requirements for waveguide transmission, while simultaneously improving the system's light utilization and integration. Specifically, the triangular prism group includes a first optical surface, a second optical surface, and a third optical surface, which are respectively opposite to the display and imaging unit, the optical waveguide unit, and the reflector group. A quarter-wave plate structure is provided between the reflector surface and the third optical surface of the reflector group, so that the image light undergoes polarization state rotation after passing through the quarter-wave plate, distinguishing it from the incident polarization state. This allows for effective separation by the polarization structure without backtracking, thereby achieving unidirectional optical path transmission, reducing stray light interference, and improving the contrast and imaging clarity of the AR display.

[0064] In some other possible implementations, this application provides an in-vehicle AR display device, the in-vehicle AR display device including... Figure 1The AR display module described in several embodiments thereof. Exemplarily, in-vehicle AR devices include, for example, in-vehicle HUDs (head-up displays), in-vehicle AR glasses, etc., and this application does not impose any limitations in this regard.

[0065] In some other possible implementations, this application provides a vehicle equipped with the in-vehicle AR display device described above.

[0066] It should also be noted that the terms "first," "second," etc. (if applicable) in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0067] The term "and / or" in the embodiments of this application is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0068] The above description is only for the purpose of enabling those skilled in the art to understand the technical solution of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this application shall be included within the scope of protection of this application.

Claims

1. An AR display module, characterized in that, The AR display module includes: The light-emitting unit (110) is used to emit illumination light; The display and imaging unit (120) is used to modulate the illumination light according to the image information to obtain image light carrying the image information; An optical path coupling unit (130) is used to couple the image light into the incident end of an optical waveguide unit (140); The optical waveguide unit (140) is used to guide the image light to the eye box region (150). The optical path coupling unit (130) includes a triangular prism (131) and a mirror group (132). The triangular prism (131) includes a first optical surface (131-1), a second optical surface (131-2), and a third optical surface (131-3) that are connected in pairs and end to end. The first optical surface (131-1) is opposite to the emitting end of the display and imaging unit (120), the second optical surface (131-2) is opposite to the incident end of the optical waveguide unit (140), and the third optical surface (131-3) is opposite to the reflecting surface (132-1) of the mirror group (132). A first polarization beam splitter is formed on the second optical surface (131-2). The first polarization beam splitter is used to filter the polarization state of light passing through the triangular prism (131) from the third optical surface (131-3). The mirror assembly (132) integrates a quarter-wave plate structure, which is located between the reflecting surface (132-1) and the third optical surface (131-3).

2. The AR display module according to claim 1, characterized in that, The reflecting surface (132-1) is a freeform surface structure, and the surface parameters of the freeform surface structure are determined based on the incident range and critical angle of the incident end of the optical waveguide unit (140).

3. The AR display module according to claim 1, characterized in that, The optical waveguide unit (140) adopts an array waveguide structure, which includes multiple sub-optical waveguide units arranged in parallel along the propagation direction of the image light.

4. The AR display module according to claim 1, characterized in that, The light-emitting unit (110) includes a light source (111) for emitting the illumination light; The light-emitting unit (110) also includes a collimating lens group (112) for reducing the divergence angle of the illumination light.

5. The AR display module according to any one of claims 1-4, characterized in that, The display and imaging unit (120) includes a display chip (121) and a diffusion display unit (122). The display chip (121) is used to receive illumination light and modulate the illumination light according to the image information to obtain a modulated beam carrying the image information; The diffusion display unit (122) is used to homogenize and diffuse the modulated beam.

6. The AR display module according to claim 5, characterized in that, The display and imaging unit (120) also includes an imaging lens group (123). The imaging lens group (123) is used to perform imaging correction and angle modulation on the homogenized and diffused modulated beam output by the diffusion display unit (122) to obtain the image light; and to transmit the image light through the output end of the display and imaging unit (120) to the first optical surface (131-1).

7. The AR display module according to any one of claims 1-4, characterized in that, The AR display module also includes an ambient light detection unit (160). The ambient light detection unit (160) is located at the output end of the optical waveguide unit (140) and is used to detect the intensity of ambient light. The light-emitting unit (110) is also used to adjust the brightness of the illumination light according to the light intensity.

8. The AR display module according to any one of claims 1-4, characterized in that, A heat dissipation component is integrated in the light-emitting unit (110) and / or the display and imaging unit (120), the heat dissipation component being used to perform heat dissipation operation when the temperature of the light-emitting unit (110) and / or the display and imaging unit (120) reaches a first temperature threshold.

9. A vehicle-mounted AR display device, characterized in that, The vehicle-mounted AR display device includes the AR display module according to any one of claims 1-8.

10. A vehicle, characterized in that, The vehicle is equipped with the in-vehicle AR display device as described in claim 9.

Images