Projection device and vehicle

Abstract

Provided in the present application are a projection device and a vehicle. The projection device comprises an optical engine, a first mirror, a reflective diffusion screen, a transmissive diffusion screen, a second mirror and a third mirror. The optical engine emits a first light beam and a second light beam. The first mirror is located in a transmission path of the first light beam, and reflects the first light beam to form a third light beam. The reflective diffusion screen is located in a propagation path of the second light beam, and reflects the second light beam to form first image light. The transmissive diffusion screen is located in a propagation path of the third light beam, and refracts the third light beam to form second image light. The second mirror is located in a propagation path of the second image light, and reflects the second image light to form third image light, wherein the optical path length of the third image light is different from the optical path length of the first image light. The third mirror can receive the first image light and the third image light, and reflect the first image light and the third image light toward an eyebox. The embodiments of the present application enable the projection device to project clear images in at least two different focal planes without increasing the volume of the projection device.

Description

Projection devices and vehicles

[0001] This application claims priority to Chinese Patent Application No. 202520566356.5, filed on March 26, 2025, entitled “Projection Device and Vehicle”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of projection devices, specifically to a projection device and a means of transportation. Background Technology

[0003] In recent years, with the intelligent development of vehicles and other transportation tools, projection devices such as head-up displays (HUDs) have been applied to an increasingly wide range of scenarios. HUDs can present information directly and accurately within the horizontal field of vision, allowing drivers to obtain all important information such as speed, warning signals, and navigation arrows without having to look down at the instrument cluster or auxiliary displays.

[0004] For basic vehicle information (such as speed, mileage, fuel level, etc.), to avoid interfering with road conditions, the image is usually projected onto an area closer to the vehicle. However, for information enabling augmented reality interaction, such as navigation and warnings, to better blend with the external road surface, the image is generally projected onto an area farther from the vehicle. Therefore, the projected image needs to be projected onto two different focal planes.

[0005] For traditional head-up display solutions, achieving dual-focal-plane imaging typically requires two optical engines and two sets of reflective optical systems to achieve two different projection distances, which undoubtedly increases costs and the size of the projection device. Summary of the Invention

[0006] The embodiments of this application provide a projection device and a vehicle that can project clear images of at least two different focal planes without increasing the size of the projection device.

[0007] In a first aspect, this application provides a projection device, including an optical engine, a first reflector, a reflective diffuser screen, a transmissive diffuser screen, a second reflector, and a third reflector. The optical engine is capable of emitting a first light beam and a second light beam. The first reflector is located within the transmission path of the first light beam and is used to reflect the first light beam to form a third light beam. The reflective diffuser screen is located within the propagation path of the second light beam and is capable of reflecting the second light beam to form a first image light. The transmissive diffuser screen is located within the propagation path of the third light beam and is capable of refracting the third light beam to form a second image light. The second reflector is located within the propagation path of the second image light and is used to reflect the second image light to form a third image light, the optical path of the third image light being different from that of the first image light. The third reflector is capable of receiving the first image light and the third image light and is used to reflect them towards the user's eyepiece.

[0008] In this embodiment, the first beam emitted by the optical engine passes sequentially through a first reflecting mirror, a transmission diffuser, a second reflecting mirror, and a third reflecting mirror to form a third image beam. This third image beam is reflected from a surface such as glass and then transmitted to the user's eye box. The second beam emitted by the optical engine passes sequentially through a reflection diffuser and a third reflecting mirror to form the first image beam. This third image beam is also reflected from a surface such as glass and then transmitted to the user's eye box.

[0009] Because the optical path length of the first beam forming the third image light is different from that of the second beam forming the first image light, the focal lengths of the images presented by the third image light and the first image light are different. The image with a longer focal length can provide information for augmented reality interactions such as vehicle navigation and warnings. This interactive information can be displayed at a greater distance from the vehicle, thus better blending with the external road surface. The image with a shorter focal length can provide basic vehicle information (such as speed, mileage, and fuel level). This basic vehicle information is displayed in an area closer to the vehicle, and can be imaged at different focal lengths with the more distant interactive information, avoiding interference with navigation or warning interactions.

[0010] The projection assembly provided in this application embodiment can form projected images with different focal planes using only one set of optical engines. Reducing the number of optical engines in the projection assembly can reduce the overall size of the projection assembly, simplify the production cost of the projection assembly, and reduce the volume requirements of the projection assembly for installation space, making the projection assembly easier to install in more usage scenarios.

[0011] Furthermore, the transmission diffuser screen in this embodiment can refract the third light beam to form a second image light, thereby changing the propagation direction of the second light beam. By adjusting the refraction direction of the second image light by the transmission diffuser screen, the second image light can be bent towards the second reflector. The transmission diffuser screen can diffuse a single light beam into multiple imaging beams, improving the user's visual experience. The diffuser screen can diffuse the light beam across the entire eye box area, so users can view the image from different eye positions within the eye box without experiencing image distortion or blurring.

[0012] It is known that before installing a diffusion screen, it is generally necessary to accurately measure the distance between the optical engine and the diffusion screen, and calculate the appropriate focal length based on the projection ratio of the projection device and the required image size. The diffusion screen needs to be installed at a specific focal length to ensure the quality and clarity of the projected image.

[0013] The second reflector in this embodiment of the application serves to adjust the propagation direction and optical path of the third image light. Adjusting the propagation direction of the third image light allows for adjustment of the imaging position, ensuring that the image position conforms to the user's usage habits. Adjusting the optical path of the third image light adjusts the distance between the image position and the user. By adjusting the optical path, the second reflector ensures that the position of the image formed by the third image light is on a different focal plane than the position of the image formed by the first image light, thus preventing interference from the image information on the other focal plane when the user is reading image information from one focal plane.

[0014] In one possible implementation, the projection device further includes a beam splitter located within the propagation path of the first image light and the third image light. The beam splitter is capable of reflecting the first image light so that it is reflected from the beam splitter to the third mirror. The third image light can propagate through the beam splitter to the third mirror.

[0015] In this embodiment, the first image light can first propagate to the beam splitter, and then propagate to the third reflecting mirror via the beam splitter. Since the optical path of the first image light can be folded by the beam splitter during propagation, the space required for the first image light to propagate is reduced, allowing the first image light to extend its optical path within a limited space. This increases the distance between the position of the image formed by the first image light and the user's eyepiece, resulting in the image being formed at a more distant location.

[0016] The third image light can pass through the beam splitter. Therefore, the optical path of the third image light will not restrict the setting area of ​​the beam splitter, so that the setting position of the beam splitter only needs to satisfy the propagation direction and optical path of the first image light.

[0017] In one possible implementation, the transmission diffusion screen is located on the side of the beam splitter away from the reflection diffusion screen.

[0018] In this embodiment, the first reflector separates the first beam from the second beam, allowing the reflective diffuser and the transmissive diffuser to be located on different sides of the beam splitter, avoiding excessive space occupation caused by placing them side-by-side. By dividing the installation space of the reflective and transmissive diffusers into smaller units, the internal space of the projection assembly can be utilized more fully, thereby reducing the size of the projection assembly. This compact design allows the projection assembly to occupy less installation space, enabling its application in scenarios with limited installation space.

[0019] In one possible implementation, the distance between the light-emitting surface of the optical engine and the first reflecting mirror is less than the distance between the light-emitting surface of the optical engine and the reflective diffusion screen.

[0020] In one possible implementation, the first and second reflectors are located on opposite sides of the transmission diffusion screen.

[0021] In one possible implementation, the sum of the optical path lengths of the first beam, the third beam, the second image beam, and the third image beam is less than the sum of the optical path lengths of the second beam and the first image beam.

[0022] In this embodiment, the distance between the imaging focal plane of the third image light and the user's eyelid is less than the distance between the imaging focal plane of the first image light and the user's eyelid. That is, the imaging focal plane of the third image light can be a focal plane closer to the user, while the imaging focal plane of the first image light can be a focal plane farther from the user.

[0023] In one possible implementation, the sum of the optical path lengths of the first beam and the third beam is the same as the optical path length of the second beam.

[0024] In this embodiment, the optical engine can emit a first beam and a second beam through the same lens. Therefore, the optical engine does not need to make separate adjustments to the first beam or the second beam. Consequently, the light emission process of the optical engine is relatively simple. The simpler the light emission process of the optical engine, the simpler its structure, and therefore, the easier it is to coordinate the various parts of the optical engine, resulting in more reliable performance.

[0025] In one possible implementation, the sum of the optical path lengths of the second image light and the third image light is less than the optical path length of the first image light.

[0026] In this embodiment, the beam splitter can increase the optical path of the first image light so that the imaging position of the first image light can be further away from the user than the imaging position of the third image light.

[0027] In one possible implementation, the projection device further includes a fourth reflector located within the propagation path of the second beam, which is capable of reflecting the second beam toward the reflective diffusion screen.

[0028] In this embodiment, the fourth reflector allows the light from the optical engine to propagate without directly to the reflective diffusion screen, thus enabling the relative positions of the optical engine and the reflective diffusion screen to be varied. This flexible positioning of the optical engine allows the projection component to avoid interfering with the vehicle's structure when installed, allowing it to adapt to the changing shape within the vehicle's installation space.

[0029] In one possible implementation, the projection device further includes a first control structure connected to a second reflector, the first control structure being capable of moving and / or rotating the second reflector.

[0030] In this embodiment, the first control structure can translate or rotate the second reflector to change the optical path and propagation angle of the third image light. When the optical path of the third image light changes, the imaging position of the third image light can be closer to or further away from the user's eyepiece. When the angle of the third image light changes, the imaging position of the third image light can change in the height direction of the vehicle, thereby adjusting the user's downward viewing angle of the image to make the image conform to the user's usage habits.

[0031] In one possible implementation, the projection device further includes a second control structure connected to the first reflector, the second control structure being capable of moving and / or rotating the first reflector.

[0032] In this embodiment, the angle and position of the first reflector can be adjusted to ensure that when the third beam reaches the transmission diffusion screen, the transmission diffusion screen is located at a certain focal length of the third beam, so as to ensure that the third beam can be correctly focused after passing through the transmission diffusion screen.

[0033] In one possible implementation, the projection device further includes a third control structure connected to the beam splitter, which is capable of adjusting the distance between the beam splitter and the third reflector.

[0034] In this embodiment, the position of the virtual image of the first image light can also be adjusted by adjusting the position of the beam splitter. For example, the beam splitter can be moved closer to the third reflecting mirror to shorten the optical path of the first image light, thereby bringing the position of the virtual image of the first image light closer to the user's eye box. Alternatively, the beam splitter can be moved further away from the third reflecting mirror to lengthen the optical path of the first image light, thereby making the position of the virtual image of the first image light farther from the user's eye box.

[0035] Secondly, this application provides a means of transportation, including a main body and a projection device as described above, wherein the projection device is mounted on the main body.

[0036] In one possible implementation, the body includes an imaging device capable of receiving a first image light and a third image light reflected from a third mirror, such that the first image light and the third image light are reflected by the imaging device toward the user's eye box, the first image light being reflected by the imaging device to form a first virtual image, and the third image light being reflected by the imaging device to form a second virtual image. Attached Figure Description

[0037] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0038] Figure 1 is a schematic diagram of the structure of the vehicle provided in an embodiment of this application;

[0039] Figure 2 is a schematic diagram of the first embodiment of the projection device and imaging device shown in Figure 1;

[0040] Figure 3 is an enlarged schematic diagram of the projection device shown in Figure 2;

[0041] Figure 4 is a structural schematic diagram of one light-emitting mode of the optomechanic shown in Figure 3;

[0042] Figure 5 is a schematic diagram of another light-emitting mode of the optical engine shown in Figure 3;

[0043] Figure 6 is a structural schematic diagram of another light-emitting mode of the optical engine shown in Figure 3;

[0044] Figure 7 is a schematic diagram of the second embodiment of the projection device and imaging device shown in Figure 1. Detailed Implementation

[0045] The specific embodiments of this application will now be described in more detail with reference to the accompanying drawings. Although exemplary embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in other ways different from those described herein, and therefore, this application is not limited to these embodiments.

[0046] For ease of understanding, the terminology used in the embodiments of this application will be explained first.

[0047] Multiple: refers to two or more.

[0048] Connection: should be interpreted broadly. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through an intermediary.

[0049] Perpendicularity: The perpendicularity defined in this application is not limited to an absolute perpendicular intersection (with an included angle of 90 degrees). It is permissible for non-absolute perpendicular intersections caused by factors such as assembly tolerances, design tolerances, and structural flatness. It is permissible for errors within a small angular range, such as an assembly error range of 80 to 100 degrees, which can all be understood as a perpendicular relationship.

[0050] Horizontal: The horizontal as defined in this application is not limited to an absolute planar parallel relationship (angle of 0 degrees or 180 degrees), and allows for non-absolute horizontal states caused by assembly tolerances, design tolerances, structural deformation, gravity effects, and environmental factors. In engineering practice, as long as the deviation of the actual angle from the reference horizontal plane is within a reasonable error range (e.g., ±10 degrees, i.e., within the range of 170 to 190 degrees), it can be considered to meet the horizontal relationship. This definition aims to accommodate the unavoidable small angular deviations during manufacturing and assembly, ensuring that functional requirements take precedence over absolute geometric accuracy.

[0051] The specific embodiments of this application will now be clearly described in conjunction with the accompanying drawings.

[0052] Please refer to Figure 1, which is a structural schematic diagram of a vehicle 1000 provided in an embodiment of this application. The vehicle 1000 in this embodiment can be a known vehicle 1000 such as a car, airplane, ship, or rocket, or it can be a newly emerging vehicle 1000 in the future. The car can be an electric vehicle, a gasoline-powered vehicle, or a hybrid vehicle, such as a pure electric vehicle, a range-extended electric vehicle, a hybrid electric vehicle, a fuel cell vehicle, or a new energy vehicle; this application does not specifically limit its type. The following description uses a vehicle 1000 as an example.

[0053] The vehicle 1000 includes a vehicle body 100 and a projection device 200. The projection device 200 is installed inside the vehicle body 100. In Figure 1, the X direction represents the width of the vehicle 1000. The Y direction represents the length of the vehicle 1000. The Z direction represents the height of the vehicle 1000.

[0054] It should be noted that Figure 1 is only intended to schematically illustrate the connection relationship between the vehicle body 100 and the projection device 200, and is not intended to specifically limit the connection positions, specific structures, or quantities of the various devices. Furthermore, the structures illustrated in the embodiments of this application do not constitute a specific limitation on the vehicle. In other embodiments of this application, the vehicle may include more or fewer components than shown in Figure 1, or combine some components, or split some components, or have different component arrangements.

[0055] The vehicle body 100 includes a vehicle body 110 and an imaging device 120. The imaging device 120 is connected to the vehicle body 110. The imaging device 120 serves as a carrier for projected images, clearly displaying the images projected by the projection device 200. The imaging device 120 can be a vehicle window glass, or a piece of transparent resin glass in front of the driver, etc. For ease of description, the following explanation will use a vehicle window glass as an example.

[0056] For example, the imaging device 120 can be a vehicle window such as a side window, windshield, rear window, or sunroof.

[0057] Specifically, when the imaging device 120 is the windshield, the projection device 200 can directly project important information such as vehicle speed, engine speed, fuel level, gear position, navigation instructions, traffic information, road speed limits, and / or driver assistance system status (such as lane departure warning and adaptive cruise control) onto the driver's front. This allows the driver to obtain this information in real time without looking down at the instrument panel or shifting their gaze, thereby improving driving safety and convenience.

[0058] When the imaging device 120 is a side window, the projection device 200 can project personalized welcome information, such as the owner's name, vehicle model, or customized pattern, onto the side window as the owner approaches or enters the vehicle, enhancing the owner's sense of ownership. When parking, the projection device 200 can project the size and location of the parking space, as well as guide lines, onto the side window, helping the driver complete the parking operation more easily. The projection device 200 can also support more entertainment and interactive functions, such as games and video playback, providing passengers with a richer and more diverse riding experience.

[0059] When the imaging device 120 is the rear windshield, the virtual image projected by the projection device 200 through the rear windshield can be observed by the driver using the vehicle's rearview mirror. At this time, the projection device 200 can combine the speed and position of vehicles behind the vehicle with the real scene to explain, so that the driver can better understand the position and speed of adjacent vehicles, thereby enabling the driver to better judge the timing of lane changes and improve the user's driving experience.

[0060] When the imaging device 120 is a skylight glass, the projection device 200 can project a virtual image upwards through the imaging device 120. The presented virtual image can interact with the sky or other external environment to create a realistic scene, providing entertainment or viewing functions for the user.

[0061] The following text and accompanying drawings use the imaging device 120 as an example of a windshield. However, it should be understood that the application scenarios of the imaging device 120 are not limited to this.

[0062] Please refer to Figure 2, which is a schematic diagram of the structure of the first embodiment of the projection device 200 and imaging device 120 shown in Figure 1. The following description takes a head-up display device on a vehicle as an example of the projection device 200.

[0063] The projection device 200 includes a housing 210, an optical engine 220, and an optical path folding assembly 230. Both the optical engine 220 and the optical path folding assembly 230 are mounted on the housing 210. The optical engine 220 projects the information to be displayed (such as vehicle speed, navigation instructions, etc.) onto the optical path folding assembly 230 in the form of light. The optical path folding assembly 230 forms image information, and through optical magnification, zooming, and other processing, converts the information into a visible image, which is then projected onto the imaging device 120 in front of the driver or a specific location. In this way, the driver can directly see the required information without looking down at the instrument panel or shifting their gaze.

[0064] It should be noted that the housing 210 provided in this embodiment can provide an installation position for the optical engine 220 and the optical path folding assembly 230. Furthermore, the housing 210 can be installed with the vehicle body 100 to fix the projection device 200 to the vehicle body 110. The housing 210 can be any structure that satisfies the assembly requirements of the projection device 200. The housing 210 allows image light from the optical path folding assembly 230 to pass through, enabling the image light to propagate to the imaging device 120.

[0065] In a first possible embodiment, please refer to FIG3, which is an enlarged schematic diagram of the projection device 200 shown in FIG2. The optical engine 220 is provided with a light-emitting surface 2201. Exemplarily, the optical engine 220 can be a picture generation unit (PGU). The optical engine 220 can employ a liquid crystal on silicon (LCOS) image source or a digital light processing (DLP) image source.

[0066] In this embodiment, the LCOS image source features high resolution, high contrast, and high color saturation, providing excellent image display effects. The DLP image source, with its high brightness, high contrast, and accurate color reproduction, is more suitable for applications requiring high-brightness projection. The choice of image source should be based on factors such as the specific application scenario, product requirements, and cost budget.

[0067] The optical engine 220 can emit a first beam 221 and a second beam 222, which are emitted through the light-emitting surface 2201. The first beam 221 and the second beam 222 can be emitted from the same lens of the optical engine 220, and the first beam 221 and the second beam 222 can be light rays from different regions of the same beam.

[0068] For example, please refer to Figure 4, which is a structural schematic diagram of one emission mode of the optical engine 220 shown in Figure 3. The optical engine 220 can emit light in the direction directly opposite the light-emitting surface 2201. Alternatively, please refer to Figure 5, which is a structural schematic diagram of another emission mode of the optical engine 220 shown in Figure 3. The beam of the optical engine 220 can be offset. Offset refers to an adjustment made to the overall image during image processing or display. The adjustment effect is similar to moving the entire image up or down without directly affecting the image's contrast or other attributes. Alternatively, please refer to Figure 6, which is a structural schematic diagram of yet another emission mode of the optical engine 220 shown in Figure 3. The focal plane of the beam of the optical engine 220 can be tilted relative to the light-emitting surface 2201. This can be understood as the beam emission direction of the optical engine 220 being adaptively adjusted according to the focal plane or the optical path folding component 230.

[0069] The first beam 221 and the second beam 222 can be distributed along the Z-axis. The first beam 221 and the second beam 222 can carry image information. The image information carried by the first beam 221 and the second beam 222 is different. There can be dark light 223 between the first beam 221 and the second beam 222 that does not carry image information.

[0070] In this embodiment, the dark light 223 can separate the region of the first beam 221 and the region of the second beam 222.

[0071] Referring again to Figure 3, the optical path folding assembly 230 includes a first reflector 231, a reflective diffuser 235, a transmissive diffuser 232, a second reflector 233, and a third reflector 234. The first reflector 231, the transmissive diffuser 232, the second reflector 233, and the third reflector 234 constitute the propagation path of the first beam 221. The reflective diffuser 235 and the third reflector 234 form the propagation path of the second beam 222.

[0072] It should be noted that the propagation path of a certain light beam refers to the bending path of the light beam as it propagates within the optical path folding assembly 230. The lens or mirror in the optical path folding assembly 230 is located within the propagation path of the light beam and is used to bend the optical path of the light beam, thereby changing the propagation direction of the light beam.

[0073] Specifically, the first reflector 231 is located within the transmission path of the first beam 221. The first reflector 231 reflects the first beam 221 to form a third beam 224, and directs the third beam 224 toward the transmission diffusion screen 232. The transmission diffusion screen 232 can refract the third beam 224 to form the second image light 225. For example, the transmission diffusion screen 232 can be located on one side of the first beam 221 and on the positive Z-axis side.

[0074] In this embodiment, the first reflector 231 can adjust the propagation angle of the third beam 224 so that the third beam 224 can propagate toward the transmission diffusion screen 232.

[0075] In one possible implementation, the projection device 200 further includes a second control structure (not shown), which is connected to the first reflector 231 and is capable of moving and / or rotating the first reflector 231.

[0076] In this embodiment, the angle and position of the first reflector 231 can be adjusted to ensure that when the third beam 224 reaches the transmission diffusion screen 232, the transmission diffusion screen 232 is located at a certain focal length of the third beam 224, so as to ensure that the third beam 224 can be correctly focused after passing through the transmission diffusion screen 232.

[0077] In this embodiment, the transmission diffusion screen 232 can refract the third beam 224 to form a second image light 225, thereby changing the propagation direction of the second beam 222. Through the refraction of the second image light 225 by the transmission diffusion screen 232, the second image light 225 can propagate towards the direction of the second reflector 233, thereby further folding the optical path and allowing the volume of the projection device 200 to be further reduced.

[0078] The transmissive diffuser 232 can diffuse a single beam of light into multiple imaging beams, improving the user's visual experience. The transmissive diffuser 232 can diffuse the beam across the entire eye box area, allowing the user to view the image from different eye positions within the eye box without distortion or blurring.

[0079] The second reflector 233 is located within the propagation path of the second image light 225. The second reflector 233 is used to reflect the second image light 225 to form the third image light 226. For example, the second reflector 233 is located on the side of the transmission diffusion screen 232 facing the Z direction. The second reflector 233 can be a plane reflector or a freeform mirror.

[0080] It is known that before installing a diffusion screen, it is generally necessary to accurately measure the distance between the optical engine and the diffusion screen, and calculate the appropriate focal length based on the projection ratio of the projection device and the required image size. The diffusion screen needs to be installed at a specific focal length to ensure the quality and clarity of the projected image.

[0081] The second reflector 233 in this embodiment of the application serves to adjust the propagation direction and optical path of the third image light 226. Adjusting the propagation direction of the third image light 226 allows for adjustment of the image position formed by the third image light 226, so that the position of the image formed by the third image light 226 conforms to the user's usage habits. Adjusting the optical path of the third image light 226 allows for adjustment of the distance between the image position and the user. By adjusting the optical path, the second reflector 233 ensures that the position of the image formed by the third image light 226 is on a different focal plane than the position of the image formed by the second beam 222, thereby preventing interference from the image information on the other focal plane when the user is reading the image information on one focal plane.

[0082] In addition, the optical path folding component 230 makes the optical path more compact, which can simultaneously have a small size and a long optical path, allowing the projection device 200 to have the advantages of small size and large screen.

[0083] In one possible implementation, the projection device 200 further includes a first control structure (not shown), which is connected to the second reflector 233 and is capable of moving and / or rotating the second reflector 233.

[0084] In this embodiment, the first control structure can translate or rotate the second reflector 233 to change the optical path and propagation angle of the third image light 226. When the optical path of the third image light 226 changes, the image position of the third image light 226 can be closer to or further away from the user's eye box. When the angle of the third image light 226 changes, the image position of the third image light 226 can change in the height direction of the vehicle 1000, thereby adjusting the user's downward viewing angle of the image so that the image position conforms to the user's usage habits.

[0085] The third reflector 234 is capable of receiving the third image light 226 and propagating the third image light 226 toward the imaging device 120, which in turn reflects the third image light 226 toward the user's eye box. For example, the third reflector 234 may be located on the side of the second reflector 233 facing the Y direction (front of the vehicle). The third reflector 234 may be a curved mirror.

[0086] In this embodiment, the first light beam 221 emitted by the optical engine 220 can pass sequentially through the first reflecting mirror 231, the transmission diffusion screen 232, the second reflecting mirror 233, and the third reflecting mirror 234 to form a third image light 226. The third image light 226 can be reflected on the surface of the imaging device 120, thereby being transmitted to the user's eye box.

[0087] The curved mirror, acting as the third reflecting mirror 234, magnifies the image generated by the optical engine 220, allowing the driver to see a larger and clearer virtual image. This magnification effect makes the virtual image farther away from the eye box, reducing the focusing time and eye fatigue caused by switching between near and far distances.

[0088] Because vehicle windshields have a certain curvature, projecting an image directly onto them may cause image distortion. The curved mirror design matches the curvature of the windshield, thus eliminating this distortion and ensuring that the virtual image generated by the optical engine 220 is accurately and clearly projected onto the windshield.

[0089] Referring again to Figures 2 and 3, the third image light 226 is reflected by the vehicle window glass imaging device 120 to form a second virtual image 2261. The horizontal field of view of the second virtual image 2261 is greater than or equal to 13°. The vertical field of view of the second virtual image 2261 is greater than or equal to 3°.

[0090] In this embodiment, the wider field of view makes the HUD's information display more intuitive and richer, improving the user experience. Drivers can more easily obtain the information they need, reducing operational complexity and enhancing comfort and convenience during driving.

[0091] The reflective diffuser 235 reflects the second beam 222 to form the first image light 227. The distance between the reflective diffuser 235 and the light-emitting surface 2201 of the optomechanical system 220 is greater than the distance between the first reflector 231 and the light-emitting surface 2201 of the optomechanical system 220. The optical path length of the first image light 227 is different from that of the third image light 226.

[0092] Since the first beam 221 and the second beam 222 are emitted from lenses with the same focal length, they must meet the diffusion screen at the same optical path. Therefore, the distance from which the first beam 221 reaches the transmission diffusion screen 232 is the same as the distance from which the second beam 222 reaches the reflection diffusion screen 235. Because the first reflecting mirror 231 folds the optical path of the first beam 221, and is located in the optical path between the optical engine 220 and the transmission diffusion screen 232, the distance between the light-emitting surface 2201 of the optical engine 220 and the first reflecting mirror 231 is less than the distance between the light-emitting surface 2201 of the optical engine 220 and the reflection diffusion screen 235.

[0093] Because the optical path length of the third image light 226 formed by the first beam 221 is different from that of the first image light 227 formed by the second beam 222, the focal lengths of the images presented by the third image light 226 and the first image light 227 are different. The image with a longer focal length can provide information for augmented reality interactions such as vehicle navigation and warnings. This interactive information can be displayed at a greater distance from the vehicle, thus better blending with the external road surface. The image with a shorter focal length can provide basic vehicle information (such as speed, mileage, and fuel level). This basic vehicle information is displayed in an area closer to the vehicle, and can be imaged at different focal lengths with the interactive information at a greater distance, avoiding interference with navigation or warning interactions.

[0094] The projection device 200 provided in this application embodiment can form projection images with different focal planes using only one set of optical engines 220. Reducing the number of optical engines 220 in the projection device 200 can reduce the overall size of the projection device 200, simplify the production cost of the projection device 200, and reduce the volume requirements of the installation space for the projection device 200, so that the projection device 200 can be easily installed in more usage scenarios.

[0095] Referring again to Figures 2 and 3, the third reflecting mirror 234 can receive the first image light 227 reflected from the diffusion screen 235 and use it to reflect it to the user's eye box. The first image light 227 is reflected by the imaging device 120 to form a first virtual image 2271. The horizontal field of view of the first virtual image 2271 is greater than or equal to 13°. The vertical field of view of the first virtual image 2271 is greater than or equal to 4°.

[0096] In this embodiment, the larger the horizontal field of view of the first virtual image 2271, the more information elements the HUD can display. This means that the driver can obtain more driving-related information without excessive distraction. A larger horizontal field of view helps the driver better perceive and understand the surrounding driving environment. By displaying important information in front of the driver's line of sight from a wider angle, the HUD can enhance the driver's situational awareness of the driving environment, thereby improving driving safety. A large horizontal field of view means that the driver does not need to frequently shift their gaze to view information in different locations. This helps reduce the number of times and the duration the driver's gaze leaves the road ahead, reducing safety hazards caused by gaze shifting.

[0097] A large vertical field of view allows the HUD to display more three-dimensional information. This helps drivers understand the information more intuitively, improving readability and comprehensibility. A larger vertical field of view also accommodates drivers of different heights. Drivers of different heights have different eye levels while driving. By adjusting the HUD's vertical field of view, it ensures that drivers of different heights can clearly see the information displayed on the HUD. A large vertical field of view also reduces the up-and-down head movement required for the driver to view information, thus improving driving comfort. Drivers can maintain a more natural sitting posture, reducing neck and back fatigue caused by prolonged periods of looking down or up at information.

[0098] In one possible implementation, the projection device 200 further includes a beam splitter 236 in the optical path of the second beam. The beam splitter 236 is located in the propagation path of the first image light 227 and the third image light 226. The beam splitter 236 can reflect the first image light 227, causing it to be reflected from the beam splitter 236 towards the third reflecting mirror 234. The third image light 226 can propagate through the beam splitter 236 to the third reflecting mirror 234. For example, the beam splitter 236 can be a plane mirror or a freeform mirror.

[0099] In this embodiment, the first image light 227 can propagate to the beam splitter 236, and then propagate to the third reflecting mirror 234 via the beam splitter 236. Because the optical path of the first image light 227 can be folded by the beam splitter 236 during propagation, the space required for the propagation of the first image light 227 is reduced, allowing the first image light 227 to extend its optical path within a limited space. This increases the distance between the position of the image formed by the first image light 227 and the user's eyepiece, resulting in the image of the first image light 227 being formed at a more distant position.

[0100] The third image light 226 can pass through the beam splitter 236. Therefore, the optical path of the third image light 226 will not restrict the setting area of ​​the beam splitter 236, so that the setting position of the beam splitter 236 only needs to satisfy the propagation direction and optical path of the first image light 227.

[0101] For example, the beam splitter 236 can be a polarizing beam splitter 236 or an intensity beam splitter 236.

[0102] A polarizing beam splitter 236 is an optical element used to separate the horizontal and vertical polarization of light. For example, the polarizing beam splitter 236 can achieve polarization splitting through surface coating (multilayer film) or coating (multilayer film). The third image light 226 can be P-polarized light, and the first image light 227 can be S-polarized light. The transmittance of P-polarized light can be 1, while the transmittance of S-polarized light can be less than 1, thereby achieving the effect that the beam splitter 236 allows the P-polarized component to pass through, while reflecting the vast majority of the S-polarized component.

[0103] An intensity beam splitter 236 is an optical element capable of reflecting and transmitting incident light according to a set intensity ratio. Precise splitting of light rays is achieved through a designed optical film layer. When light enters the intensity beam splitter 236, a portion of the first image light 227 is reflected back according to a set ratio, while a portion of the third image light 226 passes through.

[0104] For example, the beam splitter 236 may be located between the transmission diffuser 232 and the reflection diffuser 235.

[0105] In this embodiment, the first reflector 231 can separate the first beam 221 and the second beam 222, so that the reflective diffuser 235 and the transmission diffuser 232 are located on different sides of the beam splitter 236, avoiding the excessive space occupied by the reflective diffuser 235 and the transmission diffuser 232 being arranged side by side. Alternatively, it avoids the first beam 221 and the third beam 224 sharing a large area of ​​diffuser screen, thus avoiding excessive space occupation. By dividing the installation space of the reflective diffuser 235 and the transmission diffuser 232 into smaller parts, the internal space of the projection device 200 can be utilized more fully, thereby reducing the size of the projection device 200. The compact design allows the projection device 200 to occupy less installation space, enabling the projection device 200 to be used in scenarios with limited installation space.

[0106] The sum of the optical path lengths of the first beam 221, the third beam 224, the second image beam 225, and the third image beam 226 is less than the sum of the optical path lengths of the second beam 222 and the first image beam 227. Specifically, the sum of the optical path lengths of the first beam 221 and the third beam 224 is the same as the optical path length of the second beam 222. The sum of the optical path lengths of the second image beam 225 and the third image beam 226 is less than the optical path length of the first image beam 227.

[0107] In this embodiment, the optical engine 220 can emit a first beam 221 and a second beam 222 through the same lens. The image plane positions of the first beam 221 and the second beam 222 are the same. Therefore, the optical engine 220 does not need to make separate adjustments to the first beam 221 or the second beam 222. Thus, the light emission process of the optical engine 220 is relatively simple. The simpler the light emission process of the optical engine 220, the simpler the structure of the optical engine 220. Therefore, the coordination of the various parts of the optical engine 220 is relatively simple, and the working performance of the optical engine 220 is relatively reliable.

[0108] Beam splitter 236 and third beam 224 are spaced apart. Beam splitter 236 can reflect first image light 227. Beam splitter 236 can increase the optical path of first image light 227, so that the imaging position of first image light 227 can be farther away from the user compared to the imaging position of third image light 226. The distance between the imaging focal plane of third image light 226 and the user's eyepiece is less than the distance between the imaging focal plane of first image light 227 and the user's eyepiece. That is, the imaging focal plane of third image light 226 can be a focal plane closer to the user, while the imaging focal plane of first image light 227 can be a focal plane farther away from the user.

[0109] In some other embodiments, the position of the first virtual image 2271 of the first image light 227 can also be adjusted by adjusting the position of the beam splitter 236. For example, the beam splitter 236 can be moved closer to the third reflecting mirror 234 to shorten the optical path of the first image light 227, thereby bringing the position of the first virtual image 2271 of the first image light 227 closer to the user's eye box. Alternatively, the beam splitter 236 can be moved further away from the third reflecting mirror 234 to lengthen the optical path of the first image light 227, thereby moving the position of the first virtual image 2271 of the first image light 227 further away from the user's eye box.

[0110] In a second possible embodiment, please refer to FIG7, which is a schematic diagram of the second embodiment of the projection device 200 and imaging device 120 shown in FIG1. ​​Unlike the first embodiment of the projection device 200, the projection device 200 further includes a fourth reflector 237, which is located within the propagation path of the second beam 222 and is capable of reflecting the second beam 222 toward the reflective diffusion screen 235.

[0111] The optical engine 220 can be located on the side of the reflective diffuser 235 opposite to the Z direction (towards the bottom of the vehicle).

[0112] In this embodiment, the fourth reflector 237 allows the light from the optical engine 220 to propagate without directly to the reflective diffuser screen 235, thus enabling the relative positions of the optical engine 220 and the reflective diffuser screen 235 to be varied. This flexible positioning of the optical engine 220 allows the projection device 200 to avoid interference with other structures on the vehicle 1000 when installed thereon, allowing it to adapt to the changing shape within the vehicle 1000's installation space. For example, the projection device 200 may also include a control structure (not shown), which can be connected to the fourth reflector 237. The control structure can move or rotate the fourth reflector 237 to change its position and angle.

[0113] The above are exemplary embodiments of this application. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principles of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

Claims

1. A projection device, characterized in that, include: An optical engine capable of emitting a first beam and a second beam; A first reflecting mirror is located within the transmission path of the first beam and is used to reflect the first beam to form a third beam. A reflective diffuser screen is located within the propagation path of the second light beam, and the reflective diffuser screen is capable of reflecting the second light beam to form a first image light; A transmission diffusion screen is located within the propagation path of the third beam, and the transmission diffusion screen is capable of refracting the third beam to form a second image light; A second reflector is located within the propagation path of the second image light. The second reflector is used to reflect the second image light to form a third image light, the optical path of which is different from that of the first image light. A third reflector is capable of receiving the first image light and the third image light, and is used to reflect them to the user's eye box.

2. The projection device according to claim 1, characterized in that, The projection device further includes a beam splitter, which is located within the propagation path of the first image light and the third image light. The beam splitter is capable of reflecting the first image light so that the first image light is reflected from the beam splitter to the third reflecting mirror. The third image light can propagate through the beam splitter to the third reflecting mirror.

3. The projection device according to claim 2, characterized in that, The transmission diffusion screen is located on the side of the beam splitter that is away from the reflection diffusion screen.

4. The projection device according to claim 3, characterized in that, The distance between the light-emitting surface of the optical engine and the first reflecting mirror is less than the distance between the light-emitting surface of the optical engine and the reflective diffusion screen.

5. The projection device according to claim 4, characterized in that, The first reflector and the second reflector are located on opposite sides of the transmission diffusion screen.

6. The projection device according to claim 5, characterized in that, The sum of the optical path lengths of the first beam, the third beam, the second image beam, and the third image beam is less than the sum of the optical path lengths of the second beam and the first image beam.

7. The projection device according to claim 6, characterized in that, The sum of the optical path lengths of the first beam and the third beam is the same as the optical path length of the second beam.

8. The projection device according to claim 7, characterized in that, The sum of the optical path lengths of the second image light and the third image light is less than the optical path length of the first image light.

9. The projection device according to any one of claims 1-8, characterized in that, The projection device further includes a fourth reflector located within the propagation path of the second beam, which is capable of reflecting the second beam toward the reflective diffusion screen.

10. The projection device according to any one of claims 1-8, characterized in that, The projection device further includes a first control structure, which is connected to the second reflector and is capable of moving and / or rotating the second reflector.

11. The projection device according to any one of claims 1-8, characterized in that, The projection device further includes a second control structure, which is connected to the first reflector and is capable of moving and / or rotating the first reflector.

12. The projection device according to any one of claims 2-8, characterized in that, The projection device further includes a third control structure connected to the beam splitter, which is capable of adjusting the distance between the beam splitter and the third reflector.

13. A means of transportation, characterized in that, It includes a body and a projection device as described in any one of claims 1-12, wherein the projection device is mounted on the body.

14. The means of transport according to claim 13, characterized in that, The body includes an imaging device capable of receiving the first image light and the third image light reflected from the third reflector, such that the first image light and the third image light are reflected by the imaging device toward the user's eye box, the first image light being reflected by the imaging device to form a first virtual image, and the third image light being reflected by the imaging device to form a second virtual image.

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