Image generation unit and head-up display system

Abstract

The utility model relates to the technical field of lighting design, in particular to an image generation unit and a head-up display system. The image generation unit comprises a light source, a reflection cup, a cylindrical lens, an array type optical waveguide, a diffusion sheet and a TFT screen which are sequentially arranged along a light path; the reflection cup comprises two paraboloids which are arranged up and down; light rays generated by the light source are reflected by the paraboloids and then are emitted to the cylindrical lens; the cylindrical lens comprises a concave surface facing the reflection cup and a plane far away from the reflection cup; the array type optical waveguide comprises a side surface, an array reflecting surface and a light-emitting surface, the side surface and the light-emitting surface are arranged at an included angle, the side surface and the plane of the reflection cup are oppositely arranged, and the array reflecting surface is used for receiving light from the side surface and reflecting the light to the light-emitting surface; the diffusion sheet is arranged opposite to the light emitting surface of the array type light fluctuation; the TFT screen is located on the side, away from the light emitting face, of the diffusion sheet. The reflection cup and the array type optical waveguide are simple in structure and small in size, and the matching distance range of the reflection cup and the array type optical waveguide is small, so that the image generation unit is small in size.

Description

Technical Field

[0001] This utility model relates to the field of lighting design 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. Utility Model Content

[0004] The purpose of this invention is to at least solve one of the technical problems existing in the prior art. This invention provides an image generation unit, comprising: a light source, a reflector, a cylindrical lens, an array-type optical waveguide, a diffuser, and a TFT screen arranged sequentially along an optical path; the reflector includes two parabolic surfaces arranged vertically, and the light generated by the light source is reflected by the parabolic surfaces and then directed towards the cylindrical lens; the cylindrical lens includes a concave surface facing the reflector and a flat surface away from the reflector; the array-type optical waveguide includes a side surface, an array reflective surface, and a light-emitting surface, the side surface being arranged at an angle to the light-emitting surface, and the side surface being opposite to the flat surface of the reflector; the array reflective surface is used to receive light from the side surface and reflect the light to the light-emitting surface; the diffuser is arranged opposite to the light-emitting surface of the array-type optical waveguide; the TFT screen is located on the side of the diffuser away from the light-emitting surface.

[0005] More preferably, the image generation unit further includes a light-blocking strip located on the plane of the cylindrical lens, used to block light rays passing through the edge of the cylindrical lens.

[0006] More preferably, the array of reflective surfaces includes N reflective surfaces, and the ratio of reflectivity to transmittance of the i-th reflective surface is 1 / (N+1-i).

[0007] More preferably, the angle α between the reflective surface and the light-emitting surface is 45°.

[0008] More preferably, the interval b between adjacent reflective surfaces is 6 mm.

[0009] More preferably, the incident angle of the reflector cup is in the range of 65° to 75°, and the exit angle is in the range of 14° to 17°.

[0010] More preferably, the intermediate thickness of the cylindrical lens in the optical path direction ranges from 0.4 mm to 3.4 mm.

[0011] More preferably, the distance between the cylindrical lens and the reflector cup is in the range of 1.5mm to 3.5mm.

[0012] More preferably, the radius of curvature of the concave surface ranges from -37mm to -11mm, and the focal length of the cylindrical lens ranges from -70mm to -21mm.

[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 with an image generated by the image generation unit passes through the convex reflector and the freeform reflector in sequence, and finally illuminates 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 an array-type optical waveguide to the image generation unit, the light emitted by the light source is processed. Since the reflector and the array-type optical waveguide are simple in structure and small in size, the spacing between the two is also small, thereby making the image generation unit small in size and meeting the requirements of miniaturization design. (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 output from the image imaging unit. (3) A light-blocking strip is set on the plane of the light-emitting side of the cylindrical lens to block the edge light of the cylindrical lens, ensuring that the light entering the array-type optical waveguide is parallel light that meets the requirements, and ensuring the uniformity of light output from the image imaging unit. Attached Figure Description

[0015] Figure 1 A schematic diagram of the image generation unit provided by this utility model;

[0016] Figure 2 A schematic diagram of the array-type optical waveguide provided by this utility model;

[0017] Figure 3 A schematic diagram of the reflector provided by this utility model;

[0018] Figure 4 A schematic diagram of the head-up display system provided by this utility model. Detailed Implementation

[0019] 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.

[0020] 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.

[0021] 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.

[0022] Please see Figures 1-3As shown, in this specific embodiment, an image generation unit 10 includes: a light source 100, a reflector 200, a cylindrical lens 300, an array-type optical waveguide 400, a diffuser 500, and a TFT screen 600 (color LCD screen) arranged sequentially along the optical path; the reflector 200 includes two parabolic surfaces 201 arranged vertically, and the light generated by the light source 100 is reflected by the parabolic surfaces 201 and then directed towards the cylindrical lens 300; the cylindrical lens 300 includes a concave surface 301 facing the reflector 200 and a concave surface 301 away from the reflector 200. Plane 302; Array-type optical waveguide 400 includes a side surface 401, an array reflective surface 402, and a light-emitting surface 403. The side surface 401 and the light-emitting surface 403 are arranged at an angle. The side surface 401 is opposite to the plane 302 of the reflector 200. The array reflective surface 402 is used to receive light from the side surface 401 and reflect the light to the light-emitting surface 403. A diffuser 500 is opposite to the light-emitting surface 403 of the array-type optical waveguide. The TFT screen 600 is located on the side of the diffuser 500 away from the light-emitting surface 403. By adding a reflector 200 and an array-type optical waveguide 400 to the image generation unit 10, the light emitted by the light source 100 is processed. Because the reflector 200 and the array-type optical waveguide 400 have simple structures and small sizes, the spacing between them is also small, thus making the image generation unit 10 small and meeting the miniaturization design requirements. Furthermore, by setting a cylindrical lens 300 on the light-emitting side of the reflector 200, the converging light rays emitted from the reflector 200 are diffused into parallel light, ensuring the uniformity of light emitted from the image imaging unit.

[0023] The light source 100 can be a white LED. By placing multiple LEDs on the light-incident side of the reflector 200, the problems of insufficient and uneven illumination on the TFT screen 600 are reduced. Preferably, both the light-incident and light-exit sides of the reflector 200 are rectangular surfaces, so that the light passing through the reflector 200 ultimately forms a rectangular beam that enters the cylindrical lens 300. It should be noted that the aperture size of the light-incident and light-exit sides of the reflector 200 can be determined according to the number of LEDs or the size of the TFT screen 600; no further restrictions are imposed here. The diffuser 500 refers to a directional diffuser, used to diffuse the light from the array-type optical waveguide 400, ensuring that the light reaching the TFT screen 600 is uniformly illuminated, thereby providing uniform illumination to the TFT screen 600.

[0024] In one embodiment, the image generation unit 10 further includes a light-blocking strip 700 located on the plane 302 of the cylindrical lens 300 to block light rays from the edge of the transparent cylindrical lens 300. The light-blocking strip 700, positioned on the plane 302 of the light-emitting side of the cylindrical lens 300, blocks edge light rays, ensuring that the light entering the array-type optical waveguide 400 is parallel light that meets the requirements, thus ensuring the uniformity of light output from the image imaging unit.

[0025] In one embodiment, the array reflective surface 402 includes N reflective surfaces, and the ratio of reflectivity to transmittance of the i-th reflective surface is 1 / (N+1-i).

[0026] In one embodiment, the angle α between the reflecting surface and the light-emitting surface 403 is 45°.

[0027] In one embodiment, the spacing b between adjacent reflective surfaces is 6 mm. It is understood that the spacing b between adjacent reflective surfaces refers to the distance between the center points of adjacent reflective surfaces.

[0028] In one embodiment, the incident angle of the reflector 200 ranges from 65° to 75°, and the exit angle ranges from 14° to 17°. Preferably, the incident angle is 70° and the exit angle is 15.5°, so that the light rays passing through the reflector 200 are uniformly converged to the cylindrical lens 300, and then uniformly diverged into parallel light rays by the cylindrical lens 300, so that the image generation unit 10 achieves uniform illumination.

[0029] In one embodiment, the intermediate thickness of the cylindrical lens 300 in the optical path direction ranges from 0.4 mm to 3.4 mm. Preferably, the intermediate thickness of the cylindrical lens 300 in the optical path direction is 2 mm, which facilitates the manufacturing of the cylindrical lens 300 while also meeting the requirements of miniaturization design.

[0030] In one embodiment, the distance between the cylindrical lens 300 and the reflector 200 ranges from 1.5mm to 3.5mm. Preferably, the distance between the cylindrical lens 300 and the reflector 200 is 2.6mm. Limiting the distance between the cylindrical lens 300 and the reflector 200 ensures that light enters the cylindrical lens 300 better, while also meeting the requirements of miniaturization design.

[0031] In one embodiment, the radius of curvature of the concave surface 301 ranges from -37mm to -11mm, and the focal length of the cylindrical lens 300 ranges from -70mm to -21mm. Preferably, the radius of curvature of the concave surface 301 is -19.46mm, and the focal length of the cylindrical lens 300 is -37.53mm, so that the converging light rays from the reflector cup 200 are uniformly diverged into parallel light rays, thereby uniformly illuminating the image generation unit 10.

[0032] On the other hand, please refer to Figure 4 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.

[0033] 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 in that, include: The light source, reflector, cylindrical lens, array-type optical waveguide, diffuser and TFT screen are arranged sequentially along the optical path; The reflector cup includes two parabolic surfaces arranged vertically, and the light generated by the light source is reflected by the parabolic surfaces and then directed toward the cylindrical lens; The cylindrical lens includes a concave surface facing the reflector and a flat surface away from the reflector; The array-type optical waveguide includes a side surface, an array reflective surface, and a light-emitting surface. The side surface and the light-emitting surface are arranged at an angle. The side surface is arranged opposite to the plane of the reflector. The array reflective surface is used to receive light from the side surface and reflect the light to the light-emitting surface. The diffuser is positioned opposite to the light-emitting surface of the array-type light wave; The TFT screen is located on the side of the diffuser away from the light-emitting surface.

2. The image generation unit according to claim 1, characterized in that, The image generation unit also includes a light-blocking strip located on the plane of the cylindrical lens, used to block light rays passing through the edge of the cylindrical lens.

3. The image generation unit according to claim 2, characterized in that, The array of reflective surfaces includes N reflective surfaces, and the ratio of reflectivity to transmittance of the i-th reflective surface is 1 / (N+1-i).

4. The image generation unit according to claim 1, characterized in that, The angle α between the reflecting surface and the light-emitting surface is 45°.

5. The image generation unit according to claim 1, characterized in that, The spacing b between adjacent reflective surfaces is 6 mm.

6. The image generation unit according to claim 5, characterized in that, The incident angle of the reflector cup ranges from 65° to 75°, and the exit angle ranges from 14° to 17°.

7. The image generation unit according to claim 1, characterized in that, The thickness of the cylindrical lens in the optical path direction ranges from 0.4mm to 3.4mm.

8. The image generation unit according to claim 7, characterized in that, The distance between the cylindrical lens and the reflector cup ranges from 1.5mm to 3.5mm.

9. The image generation unit according to claim 7, characterized in that, The radius of curvature of the concave surface ranges from -37mm to -11mm, and the focal length of the cylindrical lens ranges from -70mm to -21mm.

10. A head-up display system, characterized in that, include: The image generation unit, convex reflector, and freeform reflector as described in any one of claims 1-9, wherein the light rays carrying the image generated by the image generation unit pass sequentially through the convex reflector and the freeform reflector, and finally illuminate the windshield to form an image.

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