Image generation unit and head-up display system
By using a reflector cup and a sawtooth waveguide in the HUD image generation unit, combined with a cylindrical lens and a diffuser, the problems of large size and high cost are solved, achieving miniaturized and low-cost imaging effects.
Patent Information
- Application Number
- CN202520126960.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-20
- Publication Date
- 2025-12-30
- Estimated Expiration
- 2035-01-20
AI Technical Summary
Existing HUD image generation units are large and expensive, failing to meet the requirements of miniaturization and low cost.
By replacing traditional light rods and Fresnel lenses with reflector cups and sawtooth waveguides, and combining cylindrical lenses and diffusers, the light path is optimized to achieve miniaturization and cost reduction.
The miniaturized design of the image generation unit reduces manufacturing costs and improves image clarity and uniformity.
Smart Images
Figure CN223742908U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of vehicle head-up display technology, specifically to an image generation unit and a head-up display system. Background Technology
[0002] Head-up displays (HUDs), as an augmented reality system, are widely used in the field of vehicle driving. They can display vehicle driving information within the driver's horizontal line of sight, allowing the driver to keep their eyes on the road. The core component of a HUD is the Picture Generation Unit (PGU), and one of the mainstream display technologies is a TFT screen (color LCD). TFT screens have advantages such as high resolution, high contrast, and short response time, and are therefore widely used in the PGU of HUDs.
[0003] Existing image generation unit solutions mainly consist of components such as LEDs, light bars, Fresnel lenses, diffusion films, and TFT screens. The light emitted by the LEDs is converged and homogenized by the light bar, the Fresnel lens further compresses the light divergence angle, and the diffusion film disperses the light, eliminating LED images and thus achieving uniform illumination of the TFT screen. However, due to the large structural size of the light bar and Fresnel lens, and the high requirements for their placement and distance, the image generation unit is bulky, resulting in an overall large head-up display that cannot meet miniaturization design requirements. Furthermore, the high manufacturing cost and low yield of Fresnel lenses cannot meet the low-cost requirements of the image generation unit. Utility Model Content
[0004] The purpose of this utility model is to at least solve one of the technical problems existing in the prior art. This utility model provides an image generation unit, including: a light source, a reflector, a cylindrical lens, a sawtooth waveguide, a diffuser, and a TFT screen arranged sequentially along an optical path; the light source includes a light-emitting plane facing the reflector; the reflector includes an entrance port near the light-emitting plane and an exit port away from the light-emitting plane; the cylindrical lens includes a concave surface near the exit port and a light-emitting plane away from the exit port; the sawtooth waveguide is cuboid in shape, including a vertically arranged coupling surface and a coupling surface, and a reflective surface arranged parallel to the coupling surface, a sawtooth component is arranged on the side of the reflective surface away from the coupling surface, the coupling surface faces the light-emitting plane, and the coupling surface faces the diffuser; the diffuser is arranged opposite to the TFT screen.
[0005] More preferably, the angle between the light-emitting plane and the first direction is 13° to 18°, the angle between the light-emitting plane and the first direction is 1° to 20°, and the first direction is parallel to the coupling surface.
[0006] More preferably, the distance between the center point of the light-emitting plane and the coupling surface in the second direction is in the range of 6.3 mm to 8.3 mm, and the second direction is perpendicular to the first direction.
[0007] More preferably, the sawtooth assembly includes a plurality of single sawtooths, each sawtooth including a reflective unit surface, the reflective unit surface forming an angle of 40° with the second direction.
[0008] More preferably, the length of the single saw tooth in the second direction ranges from 0.05 mm to 0.33 mm.
[0009] More preferably, the document teeth are spaced apart, and the distance between adjacent single teeth is in the range of 0.05mm to 0.15mm.
[0010] More preferably, the incident angle of the reflector cup at the inlet is less than or equal to 75°, and the exit angle of the reflector cup at the outlet is less than or equal to 18°.
[0011] More preferably, the distance between the center point of the outlet and the center point of the concave surface is in the range of 2.3mm to 4.3mm.
[0012] More preferably, the center thickness of the cylindrical lens is in the range of 1mm to 3mm, and the radius of curvature of the concave surface is in the range of -17mm to -19mm.
[0013] On the other hand, this application also provides a head-up display system, including: the image generation unit, the convex reflector and the freeform reflector described above, wherein the light rays with images generated by the image generation unit pass through the convex reflector and the freeform reflector in sequence, and finally illuminate the windshield to form an image.
[0014] Compared with the prior art, the present invention has the following beneficial effects: (1) By adding a reflector and a sawtooth waveguide to the image generation unit, the light emitted by the light source is processed. The reflector and the sawtooth waveguide are simple in structure and small in size, and the spacing between them is also small, which makes the image generation unit small in size and meets the requirements of miniaturization design. Moreover, the sawtooth waveguide has low manufacturing cost, simple processing, and is easy to mass-produce, which reduces the cost of the image generation unit. (2) By setting a cylindrical lens on the light-emitting side of the reflector, the converging light emitted from the reflector is diverged into parallel light, ensuring the uniformity of light emitted by the image imaging unit. (3) The light-emitting plane of the light source and the coupling surface of the sawtooth waveguide are set at an angle to ensure that the light emitted from the coupling surface to the reflecting surface can be totally reflected to the sawtooth component of the reflecting surface, and then reflected to the coupling surface and emitted from the sawtooth waveguide, thereby improving the imaging clarity. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the structure of the image generation unit provided by this utility model;
[0016] Figure 2 A schematic diagram of the structure of the light source, reflector, and cylindrical lens provided by this utility model;
[0017] Figure 3 A partial schematic diagram of the reflector, cylindrical lens, and sawtooth waveguide provided by this utility model.
[0018] Figure 4 This is a schematic diagram of the structure of a sawtooth assembly provided in an embodiment of the present invention;
[0019] Figure 5 This is a schematic diagram of the sawtooth assembly provided in another embodiment of the present invention;
[0020] Figure 6 Schematic diagram of the light source and reflector provided by this utility model;
[0021] Figure 7 This is a schematic diagram of the head-up display system provided by this utility model. Detailed Implementation
[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.
[0023] In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0024] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0025] For ease of understanding this application, as Figures 1-4 As shown, the first direction is defined as the X direction, which is parallel to the coupling surface 141 of the sawtooth optical waveguide 140. The second direction is defined as the Y direction, which is perpendicular to the first direction, that is, the second direction is parallel to the coupling surface 142 of the sawtooth optical waveguide 140.
[0026] Please see Figure 1 As shown, in this specific embodiment, an image generation unit 10 includes: a light source 110, a reflector 120, a cylindrical lens 130, a sawtooth waveguide 140, a diffuser 150, and a TFT screen 160 arranged sequentially along the optical path. The light emitted from the light source 110 passes sequentially through the reflector 120, the cylindrical lens 130, the sawtooth waveguide 140, and the diffuser 150, and finally reaches the TFT screen 160.
[0027] Specifically, such as Figure 2 As shown, the light source 110 includes a light-emitting plane 111 facing the reflector 120. It should be noted that the light source 110 is a three-dimensional structure, and its light-emitting surface, i.e., the light-emitting plane 111, is a rectangular plane. The size of the rectangular plane determines the light emission size of the light source 110.
[0028] The reflector cup 120 includes an entrance port 121 near the light-emitting plane 111 and an exit port 122 away from the light-emitting plane 111. Both the entrance port 121 and the exit port 122 are rectangular to accommodate the light source 110 and the cylindrical lens 130. Light from the light-emitting plane 111 enters the reflector cup 120 through the entrance port 121, is reflected inside the reflector cup 120, and exits through the exit port 122. The reflector cup 120 can uniformly distribute the light, so that the light reaching the TFT screen 160 is uniform, thereby improving the quality of the projected image.
[0029] The cylindrical lens 130 includes a concave surface 131 near the exit port 122 and a light-emitting surface 132 away from the exit port 122. The concave surface 131 facilitates the cylindrical lens 130 in converging the light from the exit port 122 of the reflector 120 and uniformly emitting it as parallel light, thereby improving the quality of the projected image of the image generation unit 10. Through the cooperation of the reflector 120 and the cylindrical lens 130, the light emitted by the light source 110 can be homogenized, thereby improving the quality of the projected image.
[0030] Please refer to it again. Figure 1 As shown, the sawtooth waveguide 140 is cuboid in shape, including a vertically arranged coupling surface 141 and a coupling surface 142, and a reflecting surface 143 arranged parallel to the coupling surface 142. A sawtooth assembly 144 is arranged on the side of the reflecting surface 143 away from the coupling surface 141. The coupling surface 141 faces the light-emitting plane 132, and the coupling surface 142 faces the diffuser 150. For ease of understanding, Figure 1 The simulation demonstrates the path of light rays within the image generation unit, specifically... Figure 1 The virtual image is shown in the image. The input surface 141 receives light from the output surface 132 of the cylindrical lens 130. The light passes through the input surface 141 and is incident on the output surface 142. Due to the angle between the light and the output surface 142, total internal reflection occurs. The light then hits the reflecting surface 143, and is reflected again by the sawtooth component 144 on the reflecting surface 143 and is incident on the output surface 142. Finally, it passes through the output surface 142 and is incident on the diffuser 150. By adding a reflector 120 and a sawtooth waveguide 140 to the image generation unit 10, the light emitted by the light source 110 is processed. The reflector 120 and the sawtooth waveguide 140 have simple structures and small sizes, and the spacing between them is also small, which makes the image generation unit 10 small and meets the miniaturization design requirements. Moreover, the sawtooth waveguide 140 has low manufacturing cost, is easy to process, and is easy to mass-produce, which reduces the cost of the image generation unit 10. By setting a cylindrical lens 130 on the light-emitting side of the reflector 120, the converging light rays emitted from the reflector 120 are diverged into parallel light, ensuring the uniformity of light emitted by the image imaging unit. Furthermore, since the sawtooth waveguide 140 can change the shape or specifications of the sawtooth component 144, more flexible light path planning can be achieved.
[0031] The diffuser 150 and the TFT screen 160 are arranged opposite each other, meaning that the diffuser 150 and the TFT screen 160 overlap in the optical path to ensure that the light passing through the diffuser 150 can reach the TFT screen 160 smoothly.
[0032] In one embodiment, such as Figure 2As shown, the angle α between the emitting plane 111 and the first direction X is 13° to 18°. Setting the emitting plane 111 and the coupling surface 141 at an angle ensures that the light emitted from the emitting plane 111 can pass through the coupling surface 141 and reach the coupling surface 142 within a certain angle range to achieve total internal reflection, thereby improving the projected image quality of the image generation unit 10. When the angle α between the emitting plane 111 and the coupling surface 141 is designed to be 1° to 20°, it ensures that the light reaching the coupling surface 142 after passing through the coupling surface 141 undergoes total internal reflection, thereby ensuring that the light received by the TFT screen 160 is more uniform and improving the projection imaging quality. Preferably, the angle α between the emitting plane 111 and the first direction X is 15°.
[0033] The angle b between the light-emitting plane 132 and the first direction X is 1° to 20°, meaning that the light-emitting plane 111 and the coupling surface 141 are designed to have an angle. Considering that if the light-emitting plane 132 and the coupling surface 141 are parallel, the light rays incident on the coupling surface 141 may not undergo total internal reflection at the light-emitting plane 142, meaning they cannot reach the sawtooth assembly 144, resulting in wasted light and a decrease in image clarity, it is necessary to design the light-emitting plane 132 and the coupling surface 141 to have an angle. The angle b between the light-emitting plane 132 and the first direction X can also reduce the size of the coupling surface 141, thereby reducing the thickness of the optical waveguide and achieving a thinner image generation unit 10. Preferably, the angle b between the light-emitting plane 132 and the first direction X is 10°.
[0034] In one embodiment, such as Figure 3 As shown, the distance L1 between the center point of the light-emitting plane 132 and the coupling surface 141 in the second direction Y ranges from 6.3 mm to 8.3 mm, where the second direction Y is perpendicular to the first direction X. By controlling the distance between the light-emitting plane 132 and the coupling surface 141, it is ensured that the light emitted from the light-emitting plane 132 enters the coupling surface 141 as much as possible, improving the utilization rate of light and thus improving the quality of the projected image. Preferably, the distance L1 between the center point of the light-emitting plane 132 and the coupling surface 141 in the second direction Y is 7.3 mm.
[0035] In one embodiment, such as Figure 4 As shown, the sawtooth assembly 144 includes multiple single sawtooths 1441, which are arranged consecutively. Each single sawtooth 1441 includes a reflective unit surface 14411, and the angle c between the reflective unit surface 14411 and the second direction Y is 40°, which facilitates adjusting the light direction to be perpendicular to the coupling surface 142. It should be noted that the sawtooth optical waveguide 140 is mainly composed of the sawtooth assembly 144 and a glass substrate. The sawtooth assembly 144 has a reflective film coated on the reflective unit surface 14411 of the single sawtooth 1441, which enables the light incident on the sawtooth assembly 144 to be perpendicularly emitted from the coupling surface 142.
[0036] In one embodiment, the length d of the single sawtooth 1441 in the second direction Y ranges from 0.05 mm to 0.33 mm, which facilitates the setting of more single sawtooths 1441 on the sawtooth assembly 144 and improves the reflectivity of the sawtooth assembly 144. Preferably, the length d of the single sawtooth 1441 in the second direction Y is 0.2 mm.
[0037] In another embodiment, such as Figure 5 As shown, according to the specifications of other optical path components in the image generation unit 10, multiple single sawtooth 1441 can also be arranged at intervals. When multiple single sawtooth 1441 are arranged at intervals, the interval distance e between adjacent single sawtooth 1441 ranges from 0.05mm to 0.15mm. By arranging the single sawtooth 1441 at intervals, the light rays incident on the sawtooth assembly 144 can be covered as much as possible, improving the reflectivity of the light and thus improving the quality of the projected image. Preferably, the interval distance e between adjacent single sawtooth 1441 is 0.1mm.
[0038] In one embodiment, such as Figure 6 As shown, Figure 6 The path of the light emitted from the light source 110 within the reflector 120 is shown. The incident angle g of the reflector 120 at the inlet 121 is less than or equal to 75°, and the exit angle f of the reflector 120 at the outlet 122 is less than or equal to 18°. It should be noted that since the light-emitting plane 111 of the light source 110 is planar, and the light emitted from the light source 110 is symmetrical along the direction perpendicular to the light-emitting plane 111, the light emission angle of the light source 110 is 0° to 90°, i.e., the maximum light emission angle is 90°. The incident angle g of the reflector 120 at the inlet 121 refers to the direction of the light emitted from the light-emitting plane 111 perpendicular to the light-emitting plane 111 of the light source 110. Figure 6 The angle between the incident angle g of the reflector 120 and the direction of the light emitted from the reflector 120 at the exit port 122 is the angle between the light emitted from the reflector 120 at the exit port 122 and the direction perpendicular to the light-emitting plane 111 of the light source 110. Limiting the incident angle g of the reflector 120 helps the reflector 120 absorb uniform light emitted from the light source 110, preventing light with edge emission angles from affecting the quality of the projected image. Limiting the exit angle f of the reflector 120 helps ensure that the light directed towards the cylindrical lens 130 is as uniform as possible, improving the quality of the projected image. Preferably, the incident angle g of the reflector 120 at the entrance port 121 is 70°, and the exit angle f of the reflector 120 at the exit port 122 is 15.5°.
[0039] In one embodiment, please refer again Figure 3As shown, the distance L2 between the center point of the outlet 122 and the center point of the concave surface 131 ranges from 2.3 mm to 4.3 mm. By controlling the distance between the outlet 122 and the concave surface 131, it is easier to control the uniform entry of light emitted from the reflector cup 120 into the cylindrical lens 130. Preferably, the distance L2 between the center point of the outlet 122 and the center point of the concave surface 131 is 3.3 mm.
[0040] In one embodiment, the center thickness of the cylindrical lens 130 ranges from 1 mm to 3 mm, and the radius of curvature of the concave surface 131 ranges from -17 mm to -19 mm, so that the converging light rays from the reflector cup 120 are uniformly diverged into parallel light rays, thereby enabling the image generation unit 10 to uniformly image. Preferably, the center thickness of the cylindrical lens 130 is 2 mm, and the radius of curvature of the concave surface 131 is -17.9 mm.
[0041] On the other hand, please refer to Figure 7 As shown, this application also provides a head-up display system, including: the image generation unit 10, the convex reflector 20 and the freeform reflector 30 mentioned above. The light rays with images generated by the image generation unit 10 pass through the convex reflector 20 and the freeform reflector 30 in sequence, and finally illuminate the windshield to form an image.
[0042] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model based on the technical solution and its improved concept should be covered within the protection scope of the present utility model.
Claims
1. An image generation unit characterized by comprising: The application relates to a light source device. The light source device comprises a light source, a light cup, a cylindrical lens, a sawtooth-shaped light waveguide, a diffusion sheet and a TFT screen arranged in sequence along a light path. The light source device comprises a light-emitting plane facing the light cup. The light cup comprises an incident port close to the light-emitting plane and an emission port away from the light-emitting plane. The cylindrical lens comprises a concave surface close to the emission port and an emission plane away from the emission port. The sawtooth-shaped light waveguide is in the shape of a cuboid and comprises a coupling-in surface and a coupling-out surface arranged vertically, and a reflecting surface arranged in parallel with the coupling-out surface, wherein a sawtooth assembly is arranged on the reflecting surface away from the coupling-in surface, the coupling-in surface faces the emission plane, and the coupling-out surface faces the diffusion sheet. The diffusion sheet is arranged opposite to the TFT screen.
2. The image generation unit of claim 1, wherein, An angle between the light-emitting plane and a first direction is 13-18 degrees, an angle between the emission plane and the first direction is 1-20 degrees, and the first direction is parallel to the coupling-in surface.
3. The image generation unit of claim 2, wherein, A distance between a center point of the emission plane and the coupling-in surface in a second direction is 6.3-8.3 mm, and the second direction is perpendicular to the first direction.
4. The image generation unit of claim 3, wherein, The sawtooth assembly comprises a plurality of single sawteeth, each single sawtooth comprises a reflecting unit surface, and an angle between the reflecting unit surface and the second direction is 40 degrees.
5. The image generation unit of claim 4, wherein, A length of the single sawtooth in the second direction is 0.05-0.33 mm.
6. The image generation unit of claim 5, wherein, The single sawteeth are arranged at intervals, and an interval distance between adjacent single sawteeth is 0.05-0.15 mm.
7. The image generation unit of claim 1, wherein, An incident angle of the light cup at the incident port is less than or equal to 75 degrees, and an emission angle of the light cup at the emission port is less than or equal to 18 degrees.
8. The image generation unit of claim 1, wherein, An interval distance between a center point of the emission port and a center point of the concave surface is 2.3-4.3 mm.
9. The image generation unit of claim 1, wherein, A center thickness of the cylindrical lens is 1-3 mm, and a curvature radius of the concave surface is -17 to -19 mm.
10. A heads-up display system, characterized by, The application relates to an image generation unit, a convex mirror and a free-form mirror. The image generation unit generates light with an image, the light passes through the convex mirror and the free-form mirror in sequence, and finally irradiates on a front windshield to form an image.