A cover lens and head-up display

Abstract

The cover lens of this invention includes an incident light surface and an exit light surface. The incident light surface is used to input the display image, while the exit light surface is configured to output the display image onto the windshield. The exit light surface has a curved surface, and the first diopter of the cover lens is negatively correlated with the second diopter of the windshield. The exit light surface can compensate for the display image according to the curvature, so that when the compensated display image is output onto the windshield, the virtual image distance or field of view of the display image can be maintained within an adjustment range. Therefore, the cover lens of this invention can compensate for variations in virtual image distance and field of view caused by the curvature of windshields of different vehicle models without modifying the optical specifications of the virtual image generator.

Description

A cover lens and head-up display device A COVER LENS AND HEAD-UP DISPLAY Technical Field

[0001] This work concerns lens structures, particularly a cover lens and head-up display device related to head-up display technology. Prior Technology

[0002] Traditional automotive head-up displays (HUDs) typically generate images using a virtual image generator and project those images onto the vehicle's windshield.

[0003] The HUD displays an image that is nearly parallel to the light source by using optical collimation optics (such as convex lenses or concave mirrors). This image is then reflected by the windshield into the driver's field of vision, forming a distant virtual image that allows the driver to obtain information without taking their eyes off the road.

[0004] However, because the windshield itself has positive refractive properties, the original design of the virtual image generator to output a nearly parallel beam of light to the windshield and then converge it will cause problems such as: a shorter virtual image distance (VID) (for example, from 10 meters (M) to 5M or 3M), field of view (FOV) distortion, and image distortion.

[0005] Therefore, to improve the above problems, the virtual image generator must be redesigned for each car model's windshield to accommodate the different curvatures of the windshields in each model, such as redesigning the collimator or lens assembly. However, such redesign has problems such as extremely high cost, inability to share the supply chain, and difficulty in system maintenance.

[0006] Therefore, there is an urgent technological need for a cover lens and its head-up display device that can compensate for the changes in virtual image distance and field of view caused by the curvature of windshields of different car models without modifying the optical specifications of the virtual image generator, thereby improving the problems existing in the prior art. Summary of the Invention

[0007] In view of the aforementioned known problems, the purpose of this invention is to compensate for the changes in virtual image distance and field of view caused by the curvature of windshields of different car models without modifying the optical specifications of the virtual image generator.

[0008] To achieve the aforementioned purpose, this invention provides a cover lens comprising: an incident light surface configured to input a display image; and an exit light surface configured to output the display image onto a windshield. The exit light surface has a curved surface, which compensates for the display image according to the curved surface, such that when the compensated display image is output onto the windshield, the virtual image distance of the display image is maintained within an adjustment reference. The first diopter of the cover lens is negatively correlated with a second diopter of the windshield.

[0009] Preferably, a negative correlation between a first diopter of the cover lens and a second diopter of the windshield indicates that the first diopter is negative and the second diopter is positive; or that the first diopter is positive and the second diopter is negative.

[0010] Preferably, the refractive power range of the first diopter is ±1.5D (Diopter).

[0011] Preferably, the curved surface has a first curvature axis and a second curvature axis, and the first curvature axis is equal to the second curvature axis.

[0012] Preferably, the curved surface has a first curvature axis and a second curvature axis, the first curvature axis and the second curvature axis are not equal and are orthogonal to each other.

[0013] Preferably, the curved surface has a first curvature axis and a second curvature axis, the first curvature axis and the second curvature axis are not equal, and the first curvature axis or the second curvature axis is provided with an offset angle.

[0014] Preferably, the light-incident surface has a light-incident curved surface, the curved surface has a first curvature axis, the light-incident curved surface has a second curvature axis, the first curvature axis and the second curvature axis are not equal, and the first curvature axis or the second curvature axis has an offset angle.

[0015] Preferably, the offset angle represents an angle of 0.1° - 45° between the first curvature axis or the second curvature axis and a principal optical axis of the displayed image.

[0016] Preferably, the cover lens is a Fresnel lens.

[0017] To achieve the aforementioned purpose, this invention also provides a head-up display device, comprising: a virtual image generator configured to generate a display image and output the display image from a light-emitting area; and a cover lens as described above, disposed on the light-emitting area of ​​the virtual image generator to input the display image and output the display image to a windshield.

[0018] To make the above-mentioned objectives, features and advantages of this invention more apparent and understandable, the following detailed descriptions are provided in conjunction with the specific embodiments illustrated in the figures. Simple Explanation of the Diagram

[0019] Figure 1 shows the three views of the cover lens of this invention, where the first curvature axis is equal to the second curvature axis; Figure 2 shows the three views of the cover lens of this invention, where the first curvature axis and the second curvature axis are not equal and are orthogonal to each other; Figure 3 is a three-dimensional view of the cover lens of this invention, showing that the first curvature axis and the second curvature axis are not equal, and that the first curvature axis or the second curvature axis has an offset angle; Figure 4 shows the three-view diagram of the cover lens of this invention, where the first curvature axis and the second curvature axis are not equal, and either the first curvature axis or the second curvature axis has an offset angle; Figure 5 is a three-dimensional view of the cover lens of this invention, where the light-incident surface has a light-incident curved surface, the first curvature axis and the second curvature axis are not equal, and either the first curvature axis or the second curvature axis has an offset angle; Figure 6 shows the three views of the cover lens of this invention when the light-incident surface has a light-incident curved surface, the first curvature axis and the second curvature axis are not equal, and the first curvature axis or the second curvature axis has an offset angle; Figure 7 is a schematic diagram of the head-up display device in this work. Implementation

[0020] The advantages, features, and technical methods of this invention will be more readily understood by referring to the exemplary embodiments and accompanying drawings. This invention can be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. Rather, the embodiments provided will make this disclosure more thorough, complete, and fully convey the scope of this invention to those skilled in the art, and this invention will be defined only by the appended claims.

[0021] Additionally, the terms "comprising" and / or "including" refer to the presence of the stated features, regions, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, regions, wholes, steps, operations, elements, components, and / or combinations thereof.

[0022] To facilitate your review committee's understanding of the content and effects of this work, the following detailed description, accompanied by illustrations, illustrates various specific embodiments:

[0023] Please refer to Figures 1 to 6, which are three-view diagrams of the cover lens of this invention with the first curvature axis equal to the second curvature axis; three-view diagrams of the cover lens with the first curvature axis and the second curvature axis not equal and orthogonal to each other; three-view diagrams of the cover lens with the first curvature axis and the second curvature axis not equal and with an offset angle; three-view diagrams of the cover lens with the first curvature axis and the second curvature axis not equal and with an offset angle; three-view diagrams of the cover lens with the light-incident surface having a light-incident curved surface, with the first curvature axis and the second curvature axis not equal and with an offset angle; and three-view diagrams of the cover lens with the light-incident surface having a light-incident curved surface, with the first curvature axis and the second curvature axis not equal and with an offset angle. As shown in the figure, traditional automotive HUDs require a complete redesign of their overall optical characteristics to project virtual images at a distance of 10 meters or near infinity (≥ 10 meters) onto the windshields of different vehicle models, necessitating a redesign of the HUD's optical properties based on the curvature of the windshield. However, the cover lens of this invention can compensate for the refractive effect of the windshield by utilizing the negative correlation between the refractive power of the cover lens and the windshield, without altering the optical specifications of the virtual image generator, thereby adjusting the VID and FOV of the displayed image. Thus, the cover lens 10 of this invention can include an incident light surface 11 and an exit light surface 12.

[0024] The light-incident surface 11 can be disposed on the side of the cover lens 10 facing one of the light-out areas of a virtual image generator, and is configured to input a display image output from the light-out area.

[0025] The light-emitting surface 12 is disposed on the side of the cover lens 10 facing a windshield. It is configured to output the display image input from the light-receiving surface 11 onto the windshield after optical compensation. The light-emitting surface 12 has a curved surface, which allows it to compensate for the display image. This ensures that when the compensated display image is output onto the windshield, the virtual image distance of the display image is maintained within an adjustment reference. The adjustment reference can be set by the designer based on the second diopter of the windshield. For example, if the second diopter of the windshield is positive, the first diopter of the cover lens 10 is negative, and the range of the first diopter can be the adjustment reference of 0D - -1.5D.

[0026] Furthermore, the first diopter of the cover lens is negatively correlated with the second diopter of the windshield, which means:

[0027] The first refractive power is negative, and the second refractive power is positive; or

[0028] The first refractive power is positive, and the second refractive power is negative.

[0029] The refractive power range of this first diopter is ±1.5D.

[0030] Thus, when the light-emitting surface 12 compensates for the displayed image to maintain the virtual image distance within the adjustment reference, the first refractive power can be adjusted based on the negative correlation between the first refractive power and the second refractive power. That is, when the second refractive power is positive, the first refractive power is negative, and the adjustment reference for the range of the first refractive power can be 0D - -1.5D; when the second refractive power is negative, the first refractive power is positive, and the adjustment reference for the range of the first refractive power can be 0D - +1.5D. This allows the displayed image to be maintained at a distance of 10M to infinity, or controlled to a comfortable distance (e.g., 8M).

[0031] As shown in Figure 1, the surface may have a first curvature axis Rx (e.g., a horizontal curvature axis) and a second curvature axis Ry (e.g., a vertical curvature axis), and the first curvature axis Rx is equal to the second curvature axis Ry: Rx = Ry, so that the surface has curvature and presents an isotropic sphere. Here, the curvature axis represents the curvature along a principal direction (e.g., the X-axis or Y-axis) on the surface.

[0032] As shown in Figure 2, the surface may have a first curvature axis Rx and a second curvature axis Ry, and the first curvature axis Rx and the second curvature axis Ry are not equal: Rx ≠ Ry. The first curvature axis Rx and the second curvature axis Ry are orthogonal to each other, so that the surface presents a hyperboloid, and the cover lens 10 is formed as a hyperboloid lens.

[0033] As shown in Figures 3 and 4, the surface may have a first curvature axis Rx and a second curvature axis Ry, and the first curvature axis Rx and the second curvature axis Ry are not equal: Rx ≠ Ry. The first curvature axis Rx or the second curvature axis Ry is provided with an offset angle θ, so that the surface presents a hyperboloid, and the cover lens 10 is formed as a hyperboloid lens.

[0034] As shown in Figures 5 and 6, the light-incident surface 11 is provided with a light-incident curved surface. The curved surface has a first curvature axis Rx and a second curvature axis Ry, so that each of the two surfaces of the cover lens 10 is a cylindrical surface. The first curvature axis Rx and the second curvature axis Ry are not equal: Rx ≠ Ry. The first curvature axis Rx or the second curvature axis Ry is provided with an offset angle θ, so that the cover lens 10 is formed as a hyperboloid lens.

[0035] The offset angle θ represents the angle between the first curvature axis Rx or the second curvature axis Ry and a principal optical axis OA of the displayed image, which is 0.1° - 45°.

[0036] The light-incident surface, as described above, can be spherical, hyperbolic, aspherical, or freeform, to provide corresponding optical compensation for the displayed image.

[0037] Furthermore, the cover lens 10 can also be a Fresnel lens.

[0038] In this way, the cover lens 10 of this invention can compensate for the changes in VID and FOV caused by the curvature of the windshield of different car models without modifying the optical specifications of the virtual image generator.

[0039] Please refer to Figure 7, which is a schematic diagram of the head-up display device of this invention. As shown in the figure, the head-up display device of this invention may include a virtual image generator 20 and a cover lens 10 as described above, so as to generate a display image 21 using the virtual image generator 20 and output the display image 21 from a light-emitting area, while the cover lens 10 is disposed on the light-emitting area of ​​the virtual image generator 20 to input the display image 21 and output the display image 21 to a windshield 30.

[0040] Thus, when the optical specifications of the virtual image generator 20 are VID = 10M, FOV = 15° × 5°, and the windshield has positive refractive power, when the virtual image generator 20 without the cover lens 10 projects the displayed image 21 onto the windshield 30, and the light converging the displayed image 21 enters the eye, its VID... [<] 10M,FOV [<] 15° × 5°; When the cover lens 10 is added, the virtual image generator 20, after optical compensation via the cover lens 10, projects the displayed image 21 onto the windshield 30. When the light from the displayed image 21 enters the eye, its VID ≥ 10M, FOV ≥ []15° × 5°.

[0041] The embodiments disclosed herein are preferred embodiments. Any changes or modifications made to the parts that are derived from the technical ideas of this invention and can be easily deduced by those skilled in the art shall not fall outside the scope of the patent rights of this invention.

[0042] In conclusion, this invention, in terms of purpose, means, and effects, demonstrates technical features that are distinct from those of the conventional. Furthermore, it is novel and practical, and fully meets the requirements for a utility model patent. We earnestly request that your esteemed examiner carefully review this matter and grant a patent as soon as possible, so that it may benefit society. We would be truly grateful for your assistance.

[0043] 10: Cover lens 11: Light-receiving surface 12: Light-emitting surface 20: Virtual Image Generator 21: Displaying images 30: Windshield Rx: First curvature axis Ry: Second curvature axis OA: Main optical axis θ: Offset angle

Claims

1. A cover lens, comprising: An input surface is configured to input a display image; And a light-emitting surface configured to output the displayed image onto a windshield, the light-emitting surface having a curved surface, the light-emitting surface compensating the displayed image according to the curved surface, such that when the compensated displayed image is output onto the windshield, the virtual image distance or field of view of the displayed image is maintained within an adjustment reference; wherein a first diopter of the cover lens is negatively correlated with a second diopter of the windshield.

2. The cover lens as described in claim 1, wherein, The negative correlation between a first diopter of the cover lens and a second diopter of the windshield indicates that: the first diopter is negative and the second diopter is positive; or the first diopter is positive and the second diopter is negative.

3. The cover lens as described in claim 1, wherein, The refractive power range of this first diopter is ±1.5D.

4. The cover lens as described in claim 1, wherein, The curved surface has a first curvature axis and a second curvature axis, and the first curvature axis is equal to the second curvature axis.

5. The cover lens as described in claim 1, wherein, The curved surface has a first curvature axis and a second curvature axis, the first curvature axis and the second curvature axis are not equal and are orthogonal to each other.

6. The cover lens as described in claim 1, wherein, The curved surface has a first curvature axis and a second curvature axis, the first curvature axis and the second curvature axis are not equal, and the first curvature axis or the second curvature axis is provided with an offset angle.

7. The cover lens as described in claim 1, wherein, The light-incident surface has a light-incident curved surface, the curved surface has a first curvature axis, the light-incident curved surface has a second curvature axis, the first curvature axis and the second curvature axis are not equal, and the first curvature axis or the second curvature axis has an offset angle.

8. A cover lens as described in claim 6 or 7, wherein, The offset angle indicates that the first or second curvature axis forms an angle of 0.1° - 45° with a principal optical axis of the displayed image.

9. The cover lens as described in claim 1 is a Fresnel lens.

10. A head-up display device, comprising: A virtual image generator is configured to generate a display image and output the display image from a light-emitting area; And a cover lens as described in any one of claims 1 to 9, which is disposed on the light-emitting area of ​​the virtual image generator to input the display image and output the display image to a windshield.

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