Small-size head-up display and arrangement method thereof

Abstract

The invention relates to the technical field of head-up displays based on automobile windshields, and discloses a small-size head-up display and an arrangement method thereof.The small-size head-up display comprises an image source, a lens, a reflector and an eye box, the lens is located between the image source and the reflector, and the eye box is located between the lens and the reflector. Imaging light beams emitted by the image source enter the reflecting mirror through the lens, the reflecting mirror reflects the imaging light beams to an automobile windshield, the imaging light beams are reflected to the eye box through reflection of the automobile windshield, finally, a virtual image is formed in the range of the eye box, and a driver can see the virtual image in the air in the range of the eye box. The invention further discloses a method for arranging the positions of the lens, the reflecting mirror and the eye box, a light path is shortened by adopting one reflecting mirror and one lens, the overall size of the displayer is reduced, optical distortion and reflection loss are reduced through the reasonable arrangement method, the definition and brightness of images are improved, and therefore the wide vehicle type adaptability is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of head-up displays based on automobile windshields, and discloses a small-volume head-up display and a layout method thereof. Background Art

[0002] Head-up display (HUD) is a cutting-edge imaging technology that projects images onto the windshield, allowing the driver to view important driving information in front of their line of sight. This design greatly reduces the frequency of the driver looking down at the instrument panel or central control screen, reduces the risk of distraction while driving, and thus improves driving safety and convenience.

[0003] Traditional head-up displays (HUDs) often use complex optical path designs involving multiple optical components, which not only makes their structure complex, but also takes up valuable space under the dashboard. Although this design can meet basic functional needs, it has caused limitations in terms of spatial layout and aesthetics of the in-vehicle environment. In addition, as drivers' demand for information display continues to increase, consumers want to see more driving information on the head-up display (HUD), which requires the HUD to provide a larger display area to improve information readability and user experience. However, an increase in display size often means an increase in the size of the device, which poses new challenges to the increasingly compact and efficient interior design of modern cars. Therefore, a small-volume, high-performance head-up display (HUD) is particularly important.

[0004] Therefore, there is an urgent need for a small-volume head-up display and its layout method, which can reduce the overall volume while ensuring the imaging quality, meet the market demand for large-size imaging, and enhance the application potential of HUD in various types of vehicles. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a small-volume head-up display and a layout method thereof, which can reduce the volume of the head-up display and ensure the imaging quality.

[0006] The present invention provides a small-volume head-up display, comprising: An image source, a lens, a reflector and an eye box, wherein the lens is located between the image source and the reflector, an imaging light beam emitted by the image source passes through the lens and is incident on the reflector, and the reflector reflects the imaging light beam toward the car windshield, and after being reflected by the car windshield, the imaging light beam is reflected to the eye box, and finally a virtual image is formed within the range of the eye box, thereby realizing a head-up display function.

[0007] Furthermore, the image source is an image generating device, which uses one of a liquid crystal display plus a backlight source, an LCOS projection module, a DLP projection module or a laser projection module to generate an imaging light beam.

[0008] Furthermore, the lens is a convex lens or a concave lens, which is used to magnify the imaging light beam.

[0009] Furthermore, the lens is a glass lens or a plastic lens.

[0010] Furthermore, the reflector is located behind the lens and is a concave reflector with a curvature, and is used to reflect light to the car windshield.

[0011] The present invention also provides a method for arranging a small-volume head-up display, which is used to arrange the small-volume head-up display, comprising: Step S1, determining the spatial position and size of the virtual image according to the driver's eye height and sight angle; Step S2, determining the position of the eye box based on the driver's eye ellipsoid data or actual test data, independent of the size and spatial position of the virtual image; Step S3, according to the position of the automobile windshield, the reverse light path design is adopted to determine the position of the reflector and the lens; Further including: Setting optimization conditions, wherein the optimization conditions include: the surface curvature of the reflector; the spatial position of the reflector; the surface curvature, material, thickness and spatial position of the lens; Setting optimization targets, wherein the optimization targets include: image resolution; image size; and one or more of the relative relationship of the spatial positions of the reflector, the lens, and the image generation unit; According to the optimization conditions, optical simulation software is used to make the simulation results reach the optimization target, and the final positions of the reflector and the lens are obtained.

[0012] Step S4, determining the position of the image source according to the position of the reflector; Step S5: determining the overall layout of the head-up display according to the eye box position, the lens position and the reflector position.

[0013] The embodiments of the present invention have the following technical effects: 1. By adopting a design strategy of a single reflector and a single lens, the optical structure of the head-up display (HUD) can be significantly simplified, while effectively shortening the optical path and reducing the system volume. By closely configuring the reflector and the lens, the effective length of the optical path can be shortened, thereby reducing the overall size required for the optical system. This design makes it easier for the HUD to be integrated between the vehicle's dashboard and windshield, maintaining the simplicity and aesthetics of the interior design.

[0014] 2. One of the main functions of the lens is to magnify the image source so that the driver can clearly see important information within the normal field of vision. The lens ensures that the image maintains high clarity and contrast while being magnified through optical properties. As an optical interface, the surface shape and material properties of the windshield may introduce certain optical aberrations, such as spherical aberration and chromatic aberration. The lens can effectively compensate for these aberrations caused by the windshield, making the image finally projected into the driver's field of vision more realistic and accurate.

[0015] 3. By determining the position of the virtual image according to the driver's eye height and line of sight angle, the virtual image can be ensured to be within the optimal viewing angle, thereby improving the user's visual comfort; the reverse light path design can optimize the light propagation path, reduce optical distortion and reflection loss, and improve image clarity and brightness; by setting optimization conditions and optimization targets, and using optical simulation software for parameter optimization, it is possible to flexibly respond to different vehicle models and user needs, as well as different usage environments (such as lighting conditions, driving habits, etc.), dynamically adjust system parameters, and improve system adaptability, thereby achieving optimal performance in actual applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 This is a schematic diagram of an optical path of a small head-up display provided by an embodiment of the present invention; Figure 2 It is an enlarged diagram of the light path propagation of an image source, a lens, and a reflector of a small-volume head-up display provided by an embodiment of the present invention; Figure 3 is a flow chart of a small-volume head-up display arrangement method provided by an embodiment of the present invention; Figure 4 It is a schematic diagram of virtual image space position setting of a small-volume head-up display arrangement method provided by an embodiment of the present invention; Figure 5 This is an enlarged view of a small-volume head-up display image source, lens, and reflector provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0019] Figure 1 is a schematic diagram of an optical path of a small head-up display provided by an embodiment of the present invention. Figure 2 This is an enlarged view of the light path propagation of a small-volume head-up display image source, lens, and reflector provided by an embodiment of the present invention. Figure 1 and Figure 2 The present invention provides a small-volume head-up display, comprising: An image source 001, a lens 002, a reflector 003 and an eye box 005, wherein the lens 002 is located between the image source 001 and the reflector 003, and an imaging light beam emitted by the image source 001 first passes through the lens 002, and the reflector 003 reflects the imaging light beam toward the automobile windshield 004, and then, after being reflected by the automobile windshield 004, the imaging light beam is reflected toward the eye box 005, and finally a virtual image 006 is formed within the range of the eye box 005, thereby realizing a head-up display function.

[0020] In some embodiments, the image source 001 is an image generating device, which uses a liquid crystal display plus a backlight source, an LCOS projection module, a DLP projection module or a laser projection module to generate an imaging light beam.

[0021] In some embodiments, the lens 002 is a convex lens or a concave lens, and the specific selection depends on the requirements of the optical design, and is used to magnify the imaging light beam and correct the aberration introduced by the windshield 004, thereby improving the imaging quality and information readability of the head-up display (HUD).

[0022] In some embodiments, the image generating device such as the image source 001 includes a backlight source 001-1, and the technical implementation methods include but are not limited to white LED, single color LED, laser or projection, etc.; the image generating medium 001-2 includes but is not limited to projection diffusion film, liquid crystal display or TFT and other technologies; the lens 002 is located between the image generating medium 001-2 and the reflector 003 to correct the aberration of the system.

[0023] In some embodiments, the convex lens: amplifies the imaging light beam. The convex lens has the characteristic of focusing light and can concentrate the light beam, thereby achieving amplification of the imaging light beam. In this way, the driver can see clearer image information within the normal field of vision; corrects aberrations. When light passes through the windshield 004, aberrations may be caused due to the curvature and material properties of the glass. The use of a convex lens can effectively correct these aberrations, thereby improving the clarity and accuracy of the final image.

[0024] Concave lens: Expand the field of view. The concave lens is used to expand the field of view and is suitable for use in application scenarios that require a larger field of view. It can diverge the incident light to provide a wider imaging angle, allowing the driver to obtain information in a larger field of view; optical compensation, the concave lens can also compensate for the aberration introduced by the windshield 004 to ensure the authenticity and reliability of the displayed information.

[0025] The selection and design of lens 002 plays a key role in the imaging system of the head-up display. Whether it is a convex lens or a concave lens, its main function is to solve the aberration problem introduced by the windshield 004 and enhance the clarity and readability of the imaging beam. This optical design not only improves the performance of the HUD, but also provides the driver with a safer and more convenient driving experience. Through reasonable optical design, the HUD system can effectively meet the diverse needs of modern cars for information display.

[0026] In some embodiments, the lens 002 is a glass lens or a plastic lens.

[0027] In some embodiments, the reflector 003 is located behind the lens 002 and is a concave reflector with a curvature, and is used to reflect light to the car windshield 004.

[0028] By placing a concave reflector with curvature behind the lens, the optical system of the head-up display is optimized. The curvature radius and surface shape of the reflector are closely related to the shape of the car windshield. The combination of the two ensures effective reflection of light and clear presentation of information. This design not only improves the imaging quality, but also provides drivers with a safer and more convenient driving experience, making the intelligent display system of modern cars more reliable and efficient. The curvature and surface shape of the reflector and lens surface are calculated through software optimization, usually aspherical surfaces such as free-form surfaces or other aspherical surfaces. The ultimate goal is to achieve: the imaging system composed of the car windshield, reflector, and lens can make the light emitted by the image source form a clear, small-distortion virtual image at the eye box, and the virtual image has a certain sense of space in space.

[0029] Figure 3 is a flowchart of a small-volume head-up display arrangement method provided by an embodiment of the present invention, see Figure 3 The present invention also provides a small-volume head-up display arrangement method, comprising: Step S1, determining the spatial position and size of the virtual image according to the driver's eye height and sight angle; Step S2, determining the position of the eye box based on the driver's eye ellipsoid data or actual test data, independent of the size and spatial position of the virtual image; Specifically, the eye ellipse data includes the distance and angle information from which the driver observes the screen during actual driving; the actual test data refers to the actual use test of the HUD system on a specific driver or a group of drivers in a real or simulated driving environment, and the optimal position and size of the eye box are determined by measuring and recording the driver's line of sight position, virtual image clarity, field of view and other parameters during use. Based on the driver's eye ellipse data and actual test data, it can be ensured that the position of the eye box is more in line with the driver's actual line of sight habits, and can better adapt to the physiological characteristics of different drivers, making the eye box position more humane, improving the user's comfort and experience, and separating the determination of the eye box position from the spatial parameters of the virtual image, which can simplify the design process and reduce the complexity of design and optimization.

[0030] Step S3, according to the position of the automobile windshield, the reverse light path design is adopted to determine the position of the reflector and the lens; Step S4, determining the position of the image source according to the position of the reflector; Step S5: determining the overall layout of the head-up display according to the eye box position, the lens position and the reflector position.

[0031] In some embodiments, after determining the positions of the reflector and the lens in step S3, the method further includes: Setting optimization conditions, wherein the optimization conditions include: the surface curvature of the reflector; the spatial position of the reflector; the surface curvature, material, thickness and spatial position of the lens; Setting optimization targets, wherein the optimization targets include: image resolution; image size; and one or more of the relative relationship of the spatial positions of the reflector, the lens, and the image generation unit; According to the optimization conditions, optical simulation software is used to make the simulation results reach the optimization target, and the final positions of the reflector and the lens are obtained.

[0032] For example, Figure 4 FIG. 1 is a schematic diagram of a virtual image space position setting method of a small-volume head-up display arrangement method provided by an embodiment of the present invention, see Figure 4 , first set the specific parameters of the spatial position of the virtual image in the computer simulation software, as shown in Table 1, and then the position and size of the virtual space can be determined.

[0033] Table 1 Specific parameters of virtual image space position

[0034] According to the driver's eye ellipsoid data or actual test data, the position of the eye box is determined independently of the size and spatial position of the virtual image and imported into the computer simulation software; a reverse light path design is adopted, light is emitted from the virtual image, and after passing through the eye box, the light is refracted to the inner surface of the car windshield, a reflector is placed under the car windshield, so that the light is reflected from the inner surface of the windshield to the reflector, and the angle of the reflector is adjusted so that the reverse light can be correctly reflected to the direction of the eye box; a lens is added in the reverse propagation path of the light to improve the focusing and propagation characteristics of the light; a receiving plane is added behind the lens, and the plane serves as an image generating device.

[0035] This arrangement method can optimize the viewing angle and comfort. By determining the position of the virtual image according to the driver's eye height and line of sight angle, the virtual image can be ensured to be within the optimal viewing angle, thereby improving the user's visual comfort and reducing fatigue during driving. The head-up display can provide real-time information (such as speed, navigation, etc.) without interfering with the driver's attention, thereby improving driving safety and convenience. Reverse light path design: The reverse light path design can optimize the propagation path of light, reduce optical distortion and reflection loss, and improve the clarity and brightness of the image. Reasonable configuration of reflectors and lenses: By accurately adjusting the reflector angle and adding lenses, the propagation direction and focus of light can be effectively controlled, thereby achieving higher image resolution. Adjustable optimization condition parameters: By setting the curvature, material, thickness and other parameters of the reflector and lens as variables, it can flexibly respond to different models and user needs and improve the adaptability of the system. By adjusting the optimization condition parameters using optical simulation software, the system parameters can be dynamically adjusted according to different usage environments (such as lighting conditions, driving habits, etc.), so as to achieve the best performance in actual applications. Through sophisticated optical design, the size of the head-up display can be controlled within a small range, suitable for the space constraints of different models, and easy to install and integrate. By placing a reflector under the car windshield, the visual interference of the device is reduced, allowing the driver to have a wider field of vision. The optimization of the spatial position of the reflector, lens and image generation unit helps to reduce the loss of the optical path and improve the optical efficiency of the overall system.

[0036] It should be noted that the terms used in the present invention are only for describing specific embodiments, rather than limiting the scope of the present application. As shown in the present specification, unless the context clearly indicates an exception, the words "one", "a", "a kind of" and / or "the" do not specifically refer to the singular, but may also include the plural. The terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method or device. In the absence of more restrictions, the elements defined by the sentence "include one..." do not exclude the presence of other identical elements in the process, method or device including the elements.

[0037] It should also be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", etc. should be understood in a broad sense, for example, it 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 it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present invention.

Claims

1. A method for arranging a small-volume head-up display, characterized in that: include: Step S1, determining the spatial position and size of the virtual image according to the driver's eye height and sight angle; Step S2, determining the position of the eye box based on the driver's eye ellipsoid data or actual test data, independent of the size and spatial position of the virtual image; Step S3, according to the position of the automobile windshield, the reverse light path design is adopted to determine the position of the reflector and the lens; Step S4, determining the position of the image source according to the position of the reflector; Step S5: determining the overall layout of the head-up display according to the eye box position, the lens position and the reflector position.

2. A small-volume head-up display arrangement method according to claim 1, characterized in that: After the positions of the reflector and the lens are determined in step S3, the method further includes: Setting optimization conditions, wherein the optimization conditions include: the surface curvature of the reflector; the spatial position of the reflector; the surface curvature, material, thickness and spatial position of the lens; Setting optimization targets, wherein the optimization targets include: image resolution; image size; and one or more of the relative relationship of the spatial positions of the reflector, the lens, and the image generation unit; According to the optimization conditions, optical simulation software is used to make the simulation results reach the optimization target, and the final positions of the reflector and the lens are obtained.

3. A small-volume head-up display, used to implement a small-volume head-up display arrangement method according to any one of claims 1 to 2, characterized in that: include: An image source, a lens, a reflector and an eye box, wherein the lens is located between the image source and the reflector, an imaging light beam emitted by the image source passes through the lens and is incident on the reflector, and the reflector reflects the imaging light beam toward the car windshield, and after being reflected by the car windshield, the imaging light beam is reflected to the eye box, and finally a virtual image is formed within the range of the eye box, thereby realizing a head-up display function.

4. A small-volume head-up display according to claim 3, characterized in that: The image source is an image generating device, which adopts one of a liquid crystal display plus a backlight source, an LCOS projection module, a DLP projection module or a laser projection module to generate an imaging light beam.

5. The small-volume head-up display according to claim 3, characterized in that: The lens is a convex lens or a concave lens, and is used to magnify the imaging light beam.

6. The small-volume head-up display according to claim 3, characterized in that: The lens is a glass lens or a plastic lens.

7. The small-volume head-up display according to claim 3, characterized in that: The reflector is located behind the lens and is a concave reflector with a curvature, and is used to reflect light to the windshield of the car.

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