Internal-projection large-view-field HUD (Head Up Display) system

Abstract

The invention provides an internal-projection large-field-of-view HUD system, and the system comprises an image source which is used for emitting a light beam; the reflection imaging assembly is used for directly receiving the light beam emitted by the image source and reflecting the light beam to project a real image; and the diffusion film is arranged corresponding to the real image and is used for expanding the field angle of the real image. Compared with an HUD system adopting virtual image imaging in the prior art, the HUD system has the advantages that the light beam is directly received through the reflection imaging assembly, and the light beam is reflected so as to directly project a real image; furthermore, a diffusion film is arranged at the position of the real image, and the field angle of the real image can be expanded by the diffusion film, so that a viewer can view the real image from a larger viewing angle.

Description

Technical Field

[0001] The present application relates to the field of head-up display technology, and in particular to an internal projection large field of view HUD system. Background Art

[0002] The existing head-up display (HUD) systems all use virtual image imaging, that is, the virtual image is formed at different distances of 2.5m to 7.5m in front of the vehicle for the driver to look up and observe. However, in actual use, it is found that the virtual image imaging distance is far and is located outside the last reflector (or windshield), lacking three-dimensional and layered sense, the user's visual viewing experience is not good, and the virtual image cannot be reused, resulting in limited usage scenarios. Summary of the invention

[0003] Based on the above situation, the main purpose of the present invention is to provide an internal projection large field of view HUD system, aiming to solve the technical problems in the prior art that the head-up display system is a virtual image with a long imaging distance and is located outside the last reflector (or windshield), lacks three-dimensional sense and layering, and the user's visual viewing experience is poor, and the virtual image cannot be reused, resulting in limited usage scenarios.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0005] A first aspect of an embodiment of the present invention provides an internal projection large field of view HUD system, comprising an image source, a reflective imaging component and a diffusion film; wherein:

[0006] The image source is used to emit a light beam;

[0007] The reflective imaging component is arranged on the propagation path of the light beam emitted by the image source, and is used to directly receive the light beam emitted by the image source and reflect the light beam to project a real image;

[0008] The diffusion film is arranged corresponding to the real image and is used to expand the viewing angle of the real image.

[0009] Optionally, the field of view angle is no greater than ±80° in both the horizontal and vertical directions.

[0010] Optionally, the diffusion film is arranged at the real image position.

[0011] Optionally, the diffusion film is at least one of a microstructure diffusion film, an optical-grade diffusion film, a frosted diffusion film or a polymer diffusion film.

[0012] Optionally, when the diffusion film includes the optical-grade diffusion film, the optical-grade diffusion film is at least one of a spherical diffusion film, an optical film diffusion film or a composite diffusion film.

[0013] Optionally, the performance index P of the HUD system is obtained by the following formula:

[0014] P=w A *A+w B *B+w C *C+w D *D E *E+w F *F

[0015] Among them, A represents the field of view index, B represents the image uniformity index, C represents the image illumination index, D represents the visual comfort index, E represents the volume index of the internal projection large field of view HUD system, F represents the real image imaging effect index, and w A 、w B 、w C 、w D 、w E 、w F They respectively represent the weights of the field of view angle index, image uniformity index, real image illumination index, visual comfort index, internal projection large field of view HUD system volume index, and real image imaging effect index in the system's comprehensive performance indicators.

[0016] Optionally, the performance index P of the HUD system is obtained by the following formula:

[0017]

[0018] Where θ represents the field of view of the current HUD system, θ max Indicates the maximum allowable field of view, L center Indicates the brightness of the central area of ​​the real image, L edge Indicates the brightness of the edge area of ​​the real image, L max represents the maximum brightness value of the real image, E represents the current real image illumination, and E max represents the maximum ideal illumination of the real image, C current Indicates the contrast of the current real image, C max and C min Represents the ideal maximum and minimum contrast of the real image, V current Indicates the current HUD system volume, V max Indicates the maximum allowable volume of the HUD system, R current Indicates the resolution of the current real image, R max Indicates the ideal maximum resolution of a real image.

[0019] Optionally, the reflective imaging component includes a first reflector and a second reflector for reflecting the light beam, at least one of the first reflector and the second reflector is also used to converge the light beam, the first reflector is located in the light emitting direction of the image source, and the second reflector is located in the light beam reflection direction of the first reflector, and the light beam emitted by the image source is reflected and converged by the first reflector and the second reflector, and then emitted by the second reflector to form the real image.

[0020] Optionally, the surface formulas of the first reflector and the second reflector are:

[0021]

[0022] Among them, r 2 =x 2 +y 2 , z represents the sagittal height difference in the Z-axis direction, c represents the curvature, k represents the conic surface constant, and m and n represent the orders of x and y respectively.

[0023] Optionally, the diffusion film is located at the vehicle's onboard instrument panel and / or central control display screen.

[0024] Beneficial effects:

[0025] An internal projection large field of view HUD system provided by an embodiment of the present invention includes an image source, a reflective imaging component and a diffusion film, wherein the image source is used to emit a light beam, the reflective imaging component is used to directly receive the light beam emitted by the image source and reflect the light beam to project a real image, and the diffusion film is arranged corresponding to the real image to expand the field of view angle of the real image.

[0026] Firstly, compared with the HUD system of the prior art which adopts virtual image imaging, the embodiment of the present invention directly receives the light beam through the reflective imaging component, and reflects the light beam to directly project the real image. The real image can provide the viewer with a closer imaging visual experience. The real image is imaged at a close distance, which can produce a shallow depth of field effect similar to close-up photography, so that the background of the presented image is blurred, thereby highlighting the subject and making the presented image more three-dimensional, layered and artistic. Furthermore, the embodiment of the present invention is also provided with a diffusion film at the real image position, which can expand the field of view of the real image, so that the viewer can view the real image from a larger observation angle.

[0027] Secondly, the reflective imaging assembly of the embodiment of the present invention is configured to directly receive the light beam emitted by the image source, which has a simpler structure than entering the imaging optical assembly through an optical shaping element (such as a collimating optical element).

[0028] Thirdly, the present invention adopts a lightweight design of a reflective structure, which only includes an image source, a reflective imaging component and a diffusion film to achieve real imaging and expand the observation angle. It has a simple and compact structure and a small size, which not only saves costs but is also easy to assemble.

[0029] Other beneficial effects of the present invention will be explained in the specific implementation manner through the introduction of specific technical features and technical solutions. Through the introduction of these technical features and technical solutions, those skilled in the art should be able to understand the beneficial technical effects brought about by the technical features and technical solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The preferred implementation of the internal projection large field of view HUD system of the present invention will be described below with reference to the accompanying drawings.

[0031] Figure 1 A schematic diagram of an optical path design of an internal projection large field of view HUD system according to a preferred embodiment of the present invention;

[0032] Figure 2 yes Figure 1 Schematic diagram of the structure of the central projection large field of view HUD system;

[0033] Figure 3 yes Figure 1 Schematic diagram of the optical path design of the central projection large field of view HUD system;

[0034] Figure 4 This is a schematic diagram of an optical path design of an internal projection large field of view HUD system according to another preferred embodiment of the present invention;

[0035] Figure 5 This is a schematic diagram of an optical path design of an internal projection large field of view HUD system according to a preferred embodiment of the present invention, in which the optical path does not pass through a windshield;

[0036] Figure 6 It is a schematic diagram of the optical path design of the internal projection large field of view HUD system passing through the windshield according to a preferred embodiment of the present invention.

[0037] Reference numerals:

[0038] 1. Image source; 2. Reflective imaging component; 21. First reflector; 22. Second reflector; 23. Third reflector; 3. Light beam; 4. Diffusion film; 6. Windshield; 7. Light isolation component. DETAILED DESCRIPTION

[0039] The present invention is described below based on embodiments, but the present invention is not limited to these embodiments. In the following detailed description of the present invention, some specific details are described in detail. In order to avoid confusing the essence of the present invention, known methods, processes, procedures, and components are not described in detail.

[0040] In addition, persons of ordinary skill in the art will appreciate that the drawings provided herein are for illustration purposes and are not necessarily drawn to scale.

[0041] Unless the context clearly requires otherwise, throughout the specification and claims, the words "include", "comprising" and similar words should be interpreted in an inclusive sense rather than an exclusive or exhaustive sense; that is, in the sense of "including but not limited to".

[0042] In the description of the present invention, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0043] Before introducing the specific implementation of the present invention, some of the terms used herein are explained. It should be noted that these explanations are for the purpose of facilitating the understanding of those skilled in the art, and are not intended to limit the scope of protection claimed by the present invention.

[0044] Here are some explanations of the terms used in this article:

[0045] HUD system: The HUD (Head Up Display) system, also known as the head-up display system, is a technology that projects important information onto the driver's windshield, designed to help the driver obtain key driving information without lowering or turning his head. It should be noted that in this article, the projection position of the image is no longer limited to projecting the image onto the driver's windshield. In some usage scenarios, the projection of the image does not rely on the windshield. The optical principle of the HUD system is based on the reflection and / or refraction of light. Its basic structure includes a light source, a reflector, and a transparent display screen. The light emitted by the light source is reflected by the reflector to form a virtual image. This image is projected onto the transparent display screen and then reflected back into the driver's eyes. Since this image looks like it is in front of the driver, it can reduce the driver's line of sight and improve driving safety. The optical principle of the HUD system also involves the visual principle of the human eye. The human eye can see objects because the light reflected or emitted by the object enters the human eye. When the light enters the human eye, it is refracted by the lens and vitreous body, and then forms an inverted real image on the retina. The photoreceptor cells on the retina convert light signals into electrical signals, which are then transmitted to the brain through the optic nerve, ultimately forming the image we see. In the HUD system, the image on the display screen is reflected and enters the driver's eyes. Since this image has been reflected twice, it forms an inverted virtual image on the retina. However, due to the visual adaptability of the human eye, we can still see an upright image. In short, the optical principle of the HUD head-up display system is based on the reflection and refraction of light and the visual principle of the human eye. It reduces the driver's line of sight diversion and improves driving safety by projecting a virtual image onto a transparent display screen and then reflecting it back into the driver's eyes.

[0046] Real image and virtual image: In the HUD head-up display system, the distinction between real image and virtual image is mainly based on the imaging principle and observation method. The real image is an image formed by the convergence of actual light and can be presented on the light screen. In the HUD system, the real image usually refers to the image formed by the actual convergence of lenses or other optical elements. This image can be directly observed by adjusting the position because it does exist in a certain physical position. The virtual image is an image formed by the intersection of the reverse extension lines of the actual light and cannot be presented on the light screen. In the HUD system, the virtual image usually refers to the image formed by reflection or refraction by plane mirrors or other optical elements. Although these images are not directly formed by actual light, through the design of the optical system, the driver can observe these images without moving his eyes because they are actually formed by the intersection of the extension lines of the light path.

[0047] Image source: Also known as the picture generation unit (PGU), the image source is one of the core components of the HUD head-up display system, which is responsible for generating images. In the HUD system, the image source generates light sources, which are magnified and projected onto the driver's eye activity area, so that important driving information such as speed and navigation can be projected onto the driver's front windshield, allowing the driver to obtain driving information without lowering or turning his head. This design helps improve driving safety.

[0048] Field of View: In a HUD system, the field of view (FOV) refers to the range of vision that a viewer can see when the HUD displays content. Specifically, the field of view is usually expressed as an angle value, which indicates the angle covered by the display content in the horizontal and vertical directions.

[0049] In related technologies, HUD systems all use virtual image imaging, that is, the virtual image is formed at different distances of 2.5m to 7.5m in front of the vehicle for the driver to look up and observe. However, in actual use, it is found that the virtual image imaging distance is far and is located outside the last reflector (or windshield), which cannot achieve a shallow depth of field effect, and the user's visual viewing experience is poor.

[0050] To do this, refer to Figures 1 to 6 The embodiment of the present invention provides an internal projection large field of view HUD system, including an image source 1, a reflective imaging component 2 and a diffusion film 4. The image source 1 is used to emit a light beam 3, the reflective imaging component 2 is used to reflect and image the light beam 3, and the reflective imaging component 2 is arranged on the propagation path of the light beam 3 emitted by the image source 1. The reflective imaging component 2 is arranged to directly receive the light beam 3 emitted by the image source 1 and fold the light path of the light beam 3, and reflect the light beam 3 to the diffusion film 4 to converge into a real image. The diffusion film 4 is arranged at a position corresponding to the real image, so that the viewer can view the real image projected by the reflective imaging component 2 through the diffusion film 4, and because the diffusion film 4 has the function of expanding the viewing angle, when the viewer views the real image from the diffusion film 4, he can see a real image with a wider viewing angle.

[0051] More specifically, in the embodiment of the present invention, the image source 1 generates a light source to emit a light beam 3 carrying image information, and the image information may be, for example, vehicle instrument panel information and / or central control display screen image information, which is not limited by the present invention. The light beam 3 of the image source 1 is emitted in a direction toward the reflective imaging component 2. The light beam 3 is emitted by the image source 1 and enters the reflective imaging component 2. The reflective imaging component 2 adjusts the propagation direction and then emits the light beam, and converges into a real image at the target position in the air.

[0052] In one embodiment, the diffusion film 4 is disposed between the real image and the viewer's eyes, and the viewer observes the real image through the diffusion film. In another preferred embodiment of the present invention, the diffusion film 4 is disposed at the real image position, and the real image projected by the reflective imaging component 2 is formed on the diffusion film 4, and the viewer observes the real image on the diffusion film 4.

[0053] The reflective imaging component 2 is used to fold the optical path of the light beam 3. In the embodiment of the present invention, the optical path folding refers to designing a system using the reflective imaging component 2 to avoid introducing chromatic aberration so as to realize the reflection and display of the image in a limited optical path space. The reflective imaging component 2 is arranged in the propagation direction of the light beam 3 emitted by the image source 1. The reflective imaging component 2 is further arranged to directly receive the light beam 3 emitted by the image source 1, that is, the light beam 3 does not pass through any light beam 3 shaping element from the image source 1 to the reflection imaging component 2. The reflective imaging element realizes the optical path folding of the light beam 3 by reflecting the light beam 3. By designing the reflective imaging component 2, the light beam 3 reflected from the reflective imaging component 2 can be converged into a real image at the diffusion film 4.

[0054] Compared with the virtual image imaging adopted by the HUD system of the related art, firstly, the embodiment of the present invention directly receives the light beam through the reflective imaging component, and reflects the light beam to directly project the real image. The real image can provide the viewer with a closer visual experience of imaging. The real image is imaged at a close distance, which can produce a shallow depth of field effect similar to close-up photography, so that the background of the presented image is blurred, thereby highlighting the subject, and making the presented image more three-dimensional, layered and artistic; further, the embodiment of the present invention is also provided with a diffusion film 4 at the real image position, and the diffusion film 4 can expand the field of view of the real image, so that the viewer can view the real image from a larger viewing angle. Secondly, the reflective imaging component 2 of the embodiment of the present invention is configured to directly receive the light beam 3 emitted by the image source 1, and the structure is simpler than entering the imaging optical component through an optical shaping element such as a collimating optical element. Furthermore, the embodiment of the present invention adopts a lightweight design of a reflective structure, which only includes an image source, a reflective imaging component and a diffusion film 4 to achieve the effect of imaging as a real image and expanding the viewing angle. The structure is simple and compact, and the volume is small, which not only saves costs, but also is easy to assemble.

[0055] In the internal projection large field of view HUD system of the embodiment of the present invention, there is no need to design an eye box. If an eye box is designed, the viewing angle of the viewer will be limited within the range of the eye box. However, the HUD system of the embodiment of the present invention is designed to allow the viewer to observe the real image from a wider viewing angle. Therefore, no eye box is designed, and the viewer is not limited by the eye box and can observe the real image from a wider viewing angle.

[0056] Further, in the embodiment of the present invention, the field of view angle is not greater than ±80° in both the horizontal and vertical directions. It should be noted that the field of view angle of not greater than ±80° in the horizontal direction means that the viewer can see the content within the range of -80° to +80° on the horizontal plane; the field of view angle of not greater than ±80° in the vertical direction means that the viewer can see the content within the range of -80° to +80° in the vertical direction.

[0057] In an embodiment of the present invention, the diffusion film is at least one of a microstructure diffusion film, an optical-grade diffusion film, a frosted diffusion film or a polymer diffusion film. Further, when the diffusion film includes the optical-grade diffusion film, the optical-grade diffusion film is at least one of a spherical diffusion film, an optical film diffusion film or a composite diffusion film.

[0058] When designing an internal projection large field of view HUD system, it is necessary to comprehensively consider factors such as the field of view angle of the diffusion film 4, image uniformity, illumination, visual comfort, HUD system volume, and actual imaging effect. Therefore, it is a complex design process.

[0059] In order to simplify the design, the applicant integrates the above indicators and proposes a performance indicator P for evaluating the internal projection large field of view HUD system based on years of industry experience. The performance indicator P of the HUD system is obtained by the following formula:

[0060] P=w A *A+w B *B+w C *C+w D *D E *E+w F *F

[0061] Among them, A represents the field of view index, B represents the image uniformity index, C represents the image illumination index, D represents the visual comfort index, E represents the volume index of the internal projection large field of view HUD system, F represents the real image imaging effect index, and w A 、w B 、w C 、w D 、w E 、w F They respectively represent the weights of the field of view angle index, image uniformity index, real image illumination index, visual comfort index, internal projection large field of view HUD system volume index, and real image imaging effect index in the system's comprehensive performance indicators.

[0062] in,

[0063] The viewing angle A of the diffusion film 4 is obtained by the following formula:

[0064]

[0065] Where θ represents the field of view of the current HUD system, θ max Indicates the maximum allowed field of view.

[0066] The image uniformity B of the diffusion film 4 is obtained by the following formula:

[0067]

[0068] Among them, L center Indicates the brightness of the central area of ​​the real image, L edge Indicates the brightness of the edge area of ​​the real image, L max Indicates the maximum brightness value of the real image.

[0069] The visual comfort D of the diffusion film 4 is obtained by the following formula:

[0070]

[0071] Among them, C current Indicates the contrast of the current real image, C max and C min Indicates the ideal maximum and minimum contrast of a real image.

[0072] The HUD system volume E is obtained by the following formula:

[0073]

[0074] Among them, V current Indicates the current HUD system volume, V max Indicates the maximum allowable volume of the HUD system.

[0075] The actual imaging effect F of the diffusion film 4 is obtained by the following formula:

[0076]

[0077] Among them, R current Indicates the resolution of the current real image, R max Indicates the ideal maximum resolution of a real image.

[0078] Taking the above considerations into account, the performance index P of the HUD system in the embodiment of the present invention is obtained by the following formula:

[0079]

[0080] The above calculations result in a performance index P that is synthesized from each individual index. The higher the value, the better the product performance. Through detailed formula calculation, this performance evaluation is more rigorous and it is easy to compare the advantages and disadvantages of different products.

[0081] In some implementations of the large field of view HUD system in the embodiment of the present invention, for example Figures 1 to 3 As shown, the reflective imaging component 2 includes a first reflector 21 and a second reflector 22 for reflecting the light beam 3, at least one of the first reflector 21 and the second reflector 22 is also used to converge the light beam 3, the first reflector 21 is located in the light emitting direction of the image source 1, and the second reflector 22 is located in the reflection direction of the light beam 3 of the first reflector 21, and the light beam 3 emitted by the image source 1 is reflected and converged by the first reflector 21 and the second reflector 22, and then emitted by the second reflector 22 to form the real image at the diffusion film 4.

[0082] In some possible implementation schemes under this embodiment, the first reflector 21 is used as a secondary mirror, and can be a plane mirror, a curved mirror, a spherical mirror, an aspherical mirror or a free-curved mirror, and is configured to reflect the light beam 3 only. The second reflector 22 is used as a primary mirror, and can be a curved mirror, a spherical mirror, an aspherical mirror or a free-curved mirror, and is configured to reflect and converge the light beam 3. When in use, the light beam 3 emitted by the image source 1 is first incident on the first reflector 21, and then incident on the second reflector 22 after being reflected by the first reflector 21. The second reflector 22 reflects and converges the light beam 3 and then emits the light beam 3 to the diffusion film 4 to form a real image. It should be noted that the present invention does not impose any special restrictions on this. In other possible implementation schemes, the first reflector 21 can also be used to reflect and converge the light beam 3, and the second reflector 22 is only used to reflect the light beam 3, as long as a real image can be formed on the diffusion film 4 after reflection and convergence by the first reflector 21 and the second reflector 22.

[0083] The HUD system can directly form a real image in the diffusion film 4 by reflecting and converging the light beam 3 by the first reflector 21 and the second reflector 22. The reflective imaging component 2 only includes the first reflector 21 and the second reflector 22, has a simple structure, a small volume, a wide range of application scenarios and a low cost.

[0084] The present invention is not limited to the reflective imaging component 2 comprising only two reflectors. In other embodiments of the projection large field of view HUD system of the present invention, for example, Figure 4As shown, the reflective imaging assembly 2 includes a first reflector 21, a second reflector 22 and a third reflector 23 for reflecting a light beam 3. At least one of the first reflector 21, the second reflector 22 and the third reflector 23 is also used to converge the light beam 3. The first reflector 21 is located in the light emitting direction of the image source 1, the second reflector 22 is located in the light beam 3 reflection direction of the first reflector 21, and the third reflector 23 is located in the light beam 3 reflection direction of the second reflector 22. At the same time, the second reflector 22 is also located in the light beam 3 reflection direction of the third reflector 23. The image source 1 The emitted light beam 3 is reflected by the first reflector 21 and the second reflector 22, the light beam 3 reflected by the second reflector 22 is emitted to the third reflector 23 and reflected by the third reflector 23 and then emitted back to the second reflector 22, and finally the light beam 3 is emitted to the diffusion film 4 by the second reflector 22. During the reflection process of the light beam 3, at least one of the first reflector 21, the second reflector 22 and the third reflector 23 converges the light beam 3 so that the light beam 3 emitted by the second reflector 22 forms the real image at the diffusion film 4.

[0085] In some possible implementation schemes under this embodiment, the first reflector 21 can be a plane mirror, a curved mirror, a spherical mirror, an aspherical mirror or a free-curved mirror, and is configured to reflect the light beam 3 only. The second reflector 22 can be a curved mirror, a spherical mirror, an aspherical mirror or a free-curved mirror, and is configured to reflect and converge the light beam 3. The third reflector 23 can be a plane mirror, a curved mirror, a spherical mirror, an aspherical mirror or a free-curved mirror, and is configured to reflect the light beam 3. When in use, the light beam 3 emitted by the image source 1 first enters the first reflector 21, and then enters the second reflector 22 after being reflected by the first reflector 21. The second reflector 22 reflects the light beam 3 and then enters the third reflector 23. After the third reflector 23 reflects the light beam 3, the light beam 3 is re-emitted back to the second reflector 22. The second reflector 22 further reflects and converges the light beam 3, and the light beam 3 emitted from the second reflector 22 enters the diffusion film 4 to form a real image. Similarly, the present invention is not limited to the above-mentioned implementation scheme. It can be understood that in other possible implementation schemes, the first reflector 21 and the third reflector 23 can also be used to reflect and converge the light beam 3, as long as a real image can be formed at the diffusion film 4 after reflection and convergence by the first reflector 21, the second reflector 22 and the third reflector 23.

[0086] Compared with two reflectors, the reflective imaging assembly 2 composed of three reflectors is used. By adding a reflector, the design variables are increased, and it is easier to design a good imaging effect. The light beam 3 reflected by the second reflector 22 is directed to the third reflector 23 and reflected by the third reflector 23 and then directed back to the second reflector 22. Finally, the second reflector 22 directs the light beam 3 to the diffusion film 4. This design can save space and reduce the volume of the reflective imaging assembly 2. One reflector (the second reflector 22) performs two reflections. Without increasing the total number of lenses, the number of design variables is increased, the design difficulty is reduced, and the overall volume can be kept small.

[0087] Furthermore, if Figure 4 As shown, the internal projection large field of view HUD system of the embodiment of the present invention is further provided with a light isolator 7 on the optical path emitted by the reflective imaging component 2. The light isolator 7 is located between the diffusion film 4 and the reflective imaging component 2 and is arranged close to the reflective imaging component 2. The light isolator 7 is not completely isolated, and it has a certain transmittance. The transmittance is selected and set according to actual needs. The light isolator 7 plays the role of isolating the light of the internal device. The light beam emitted from the reflective imaging component 2 first passes through the light isolator 7 to filter the light, so that the observer cannot see the internal structure, or can only see the internal structure vaguely, so that the background of the presented image is further blurred, thereby further highlighting the subject, and making the presented image more three-dimensional, layered and artistic. Secondly, the light isolator can also reduce glare, improve contrast and enhance visual comfort.

[0088] In some preferred embodiments, the light isolation member 7 may be made of gray glass. Although gray glass performs well in reducing glare and improving contrast, it is not necessary to use only gray glass. In fact, glass of other colors may also be used.

[0089] In some other implementations of the wide field of view HUD system in the embodiments of the present invention, the image source 1 includes a first light emitting area and a second light emitting area, the first light emitting area is used to emit a first light beam 3, and the second light emitting area is used to emit a second light beam 3; the reflective imaging component 2 includes a first reflector 21 and a second reflector 22, the first reflector 21 has a first reflective area and a second reflective area, and the second reflector 22 has a third reflective area and a fourth reflective area.

[0090] When in use, the first light-emitting area emits a first light beam 3, which enters the first reflection area of ​​the first reflector 21, and after being reflected by the first reflection area, enters the third reflection area of ​​the second reflector 22, and after being reflected by the third reflection area, the light beam 3 is emitted to the first target position in the diffusion film 4 to form a first real image. The second light-emitting area emits a second light beam 3, which enters the second reflection area of ​​the first reflector 21, and after being reflected by the second reflection area, enters the fourth reflection area of ​​the second reflector 22, and after being reflected by the fourth reflection area, the light beam 3 is emitted to the second target position in the diffusion film 4 to form a second real image.

[0091] Through the internal projection large field of view HUD system of this implementation, two real image imaging is achieved only through a reflective structure, which on the one hand further increases the richness of the image, and on the other hand, by partitioning the image source 1 and the reflector, two real image imaging can be achieved through a set of image source 1 and a set of reflective structure.

[0092] Further, in some preferred implementation schemes under this embodiment, the first reflection area and the second reflection area of ​​the first reflector 21 are adjacent and do not overlap, and the third reflection area and the fourth reflection area of ​​the second reflector 22 are adjacent and do not overlap. The projection areas of the first light beam 3 and the second light beam 3 on the first reflector 21 and the second reflector 22 are adjacent and do not overlap.

[0093] In some other preferred implementation schemes under this embodiment, the first reflection area and the second reflection area of ​​the first reflector 21 partially overlap, and the third reflection area and the fourth reflection area of ​​the second reflector 22 do not overlap. In this way, the projection areas of the first light beam 3 and the second light beam 3 on the first reflection area and the second reflection area partially overlap, and after being reflected by the first reflection area and the second reflection area respectively, the projection areas on the third reflection area and the fourth reflection area are separated, that is, the optical paths of the first light beam 3 and the second light beam 3 are separated in the third reflection area and the fourth reflection area of ​​the second reflector 22. The first light beam 3 and the second light beam 3 form a first real image and a second real image in the diffusion film 4 after being reflected by the third reflection area and the fourth reflection area respectively. In this embodiment, the reflection area of ​​the first reflector 21 can be reduced, which is conducive to reducing the overall volume and facilitating application.

[0094] In this embodiment, there may be some possible implementation schemes, such as the first reflection area and the second reflection area partially overlap, and the third reflection area and the fourth reflection area partially overlap.

[0095] The light beam 3 of the HUD system of the embodiment of the present invention may not pass through the windshield 6. Figure 5 As shown, the light beam 3 emitted by the image source 1 is reflected and converged by the reflective imaging component 2 to directly form a real image on the diffusion film 4.

[0096] The light beam 3 of the HUD system of the embodiment of the present invention may also pass through the windshield 6, such as Figure 6 As shown, in some embodiments, the reflective imaging assembly 2 includes a first reflector 21 and a second reflector 22 for reflecting the light beam 3, at least one of the first reflector 21 and the second reflector 22 is also used to converge the light beam 3, the first reflector 21 is located in the light emitting direction of the image source 1, the second reflector 22 is located in the reflection direction of the light beam 3 of the first reflector 21, and the reflection direction of the light beam 3 of the second reflector 22 points to the windshield 6, the light beam 3 emitted by the image source 1 is reflected and converged by the first reflector 21 and the second reflector 22, and then the light beam 3 is emitted by the second reflector 22 to the concave surface of the windshield 6, and the concave surface of the windshield 6 reflects the light beam 3 to the diffusion film 4 to form the real image. Compared with the reflective imaging assembly 2 directly imaging on the diffusion film 4, the embodiment of the present invention utilizes the original windshield 6 on the vehicle, which is equivalent to further increasing the number of reflective lenses, increasing design variables, and can further reduce the design difficulty without increasing the volume.

[0097] Further, in the embodiment of the present invention, the first reflector 21, the second reflector 22 and the third reflector 23 are all free-form surface mirrors, and the surface shapes of the first reflector 21, the second reflector 22 and the third reflector 23 are obtained by the following formula:

[0098]

[0099] Among them, r 2 =x 2 +y 2 , z represents the sagittal height difference in the Z-axis direction, c represents the curvature, k represents the conic surface constant, and m and n represent the orders of x and y respectively.

[0100] From a design perspective, an important parameter is the magnification, which is the ratio of the real image area to the luminous area of ​​the image source 1. The magnification determines the difficulty of the design. The higher the magnification, the greater the difficulty of the design. In an embodiment of the present invention, the ratio of the real image area to the luminous area of ​​the image source 1 is 1.5-2.5, preferably 2.

[0101] In actual use, if the real image is not clear enough, the image clarity can be adjusted by adjusting the size of the image source 1, the first reflector 21, and the second reflector 22, and the position and angle of the image source 1, the first reflector 21, and the second reflector 22. Figure 1According to the surface calculation formula of the first reflector 21 and the second reflector 22, and the value of the magnification, the embodiment of the present invention proposes a set of preferred parameters, wherein the size of the image source 1 is: 50mm*25mm; the specific parameters of the first reflector 21 and the second reflector 22 are: the length of the large mirror of the second reflector 22 is 160mm, and the width is 120mm; the length of the small mirror of the first reflector 21 is 100mm, and the width is 70mm; the distance from the real image to the second reflector 22 is 500mm±20mm; the distance between the second reflector 22 and the first reflector 21 is is 250mm±20mm; the distance from the first reflector 21 to the image source 1 is 270mm±20mm; the focal length of the second reflector 22 is 400mm-500mm, the focal length of the first reflector 21 is 260mm-360mm, the second reflector 22 is deflected 10-20° around the X-axis (X in zemax is the positive direction of X inward from the paper), and the first reflector 21 is deflected 15-25° around the X-axis; assuming that the image source 1 is incident, the angle of the incident light beam 3 is 5.5°×5.5°, and the outgoing light beam 3 forms a real image size of about 100mm*50mm.

[0102] It should be noted that the set of parameters adopted in the above implementation is not the only solution, and different design results can be optimized according to actual needs.

[0103] For the embodiment in which the reflective imaging assembly 2 includes three reflectors, in actual use, if the real image is not clear enough, the image clarity can be adjusted by adjusting the size of the image source 1, the first reflector 21, the second reflector 22 and the third reflector 23, and the position and angle of the image source 1, the first reflector 21, the second reflector 22 and the third reflector 23. As an example, please refer to Figure 4 According to the surface calculation formulas of the first reflector 21, the second reflector 22 and the third reflector 23, and the value of the magnification, the embodiment of the present invention proposes a set of preferred parameters, wherein the real image size is 46mm*28mm; the image source 1 size is 40mm*20mm; the first reflector 21 size is 20mm±10mm*20mm±10mm; the second reflector 22 size is 100mm±10mm*84mm±10mm; the third reflector 23 size is 90mm±10mm*50mm±10mm; the window distance is 60mm±10mm; the image source 1 distance from the first reflector 21 is 40mm±10mm; the first reflector 21 is 50mm±10mm from the second reflector 22; the third reflector 23 is 45mm±10mm from the first reflector 21; the second reflector 22 is 60mm±10mm from the window. The image source 1 is an LCD, the first reflector 21 and the third reflector 23 are free-form surfaces, and the second reflector 22 is a plane mirror.

[0104] Through the above parameter settings, the embodiment of the present invention can obtain a clear and stable real image.

[0105] Furthermore, in the embodiment of the present invention, the diffusion film 4 is located at the position of the vehicle's onboard instrument and / or central control display screen. By setting the diffusion film 4 at the position of the vehicle's onboard instrument and / or central control display screen, the vehicle can omit the onboard instrument and / or central control display screen, that is, the original onboard instrument and / or central control display screen of the vehicle is replaced by the diffusion film 4 and the real image, which can greatly simplify the structure, reduce costs, and increase the flexibility of system functions and the diversity of display effects compared to traditional vehicles.

[0106] An embodiment of the present invention further provides a vehicle, comprising the internal projection large field of view HUD system described in any one of the above embodiments.

[0107] It will be appreciated by those skilled in the art that, under the premise of no conflict, the above-mentioned preferred solutions can be freely combined and superimposed. Among them, the flowcharts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, a program segment, or a part of a code, and the module, program segment, or a part of a code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings, for example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions. The numbering of each step in this article is only for the convenience of explanation and reference, and is not used to limit the order of execution. The specific execution order is determined by the technology itself, and those skilled in the art can determine various allowable and reasonable orders based on the technology itself.

[0108] Those skilled in the art will appreciate that, without conflict, the above-mentioned preferred solutions can be freely combined and superimposed.

[0109] It should be understood that the above-mentioned embodiments are merely illustrative and not restrictive. Without departing from the basic principles of the present invention, various obvious or equivalent modifications or substitutions that can be made by those skilled in the art to the above-mentioned details will be included in the scope of the claims of the present invention.

Claims

1. An internal projection large field of view HUD system, characterized in that: It comprises an image source (1), a reflective imaging component (2) and a diffusion film (4); wherein: The image source (1) is used to emit a light beam (3); The reflective imaging component (2) is arranged on the propagation path of the light beam (3) emitted by the image source (1), and is used to directly receive the light beam (3) emitted by the image source (1) and reflect the light beam (3) to project a real image; The diffusion film (4) is arranged corresponding to the real image and is used to expand the viewing angle of the real image.

2. The internal projection large field of view HUD system according to claim 1, characterized in that: The field of view angle is no greater than ±80° in both the horizontal and vertical directions.

3. The internal projection large field of view HUD system according to claim 1, characterized in that: The diffusion film (4) is arranged at the real image position.

4. The internal projection large field of view HUD system according to any one of claims 1 to 3, characterized in that: The diffusion film (4) is at least one of a microstructure diffusion film, an optical-grade diffusion film, a frosted diffusion film or a polymer diffusion film.

5. The internal projection large field of view HUD system according to claim 4, characterized in that: When the diffusion film (4) comprises the optical-grade diffusion film, the optical-grade diffusion film is at least one of a spherical diffusion film, an optical film diffusion film or a composite diffusion film.

6. The internal projection large field of view HUD system according to any one of claims 1-3, characterized in that: The performance index P of the HUD system is obtained by the following formula: P=w A *A+w B *B+w C *C+w D *D-w E *E+w F *F Among them, A represents the field of view index, B represents the image uniformity index, C represents the image illumination index, D represents the visual comfort index, E represents the volume index of the internal projection large field of view HUD system, F represents the real image imaging effect index, and w A 、w B 、w C 、w D 、w E 、w F They respectively represent the weights of the field of view angle index, image uniformity index, real image illumination index, visual comfort index, internal projection large field of view HUD system volume index, and real image imaging effect index in the system's comprehensive performance indicators.

7. The internal projection large field of view HUD system according to claim 6, characterized in that: The performance index P of the HUD system is obtained by the following formula: Where θ represents the field of view of the current HUD system, θ max Indicates the maximum allowable field of view, L center Indicates the brightness of the central area of ​​the real image, L edge Indicates the brightness of the edge area of ​​the real image, L max represents the maximum brightness value of the real image, E represents the current real image illumination, and E max represents the maximum ideal illumination of the real image, C current Indicates the contrast of the current real image, C max and C min Represents the ideal maximum and minimum contrast of the real image, V current Indicates the current HUD system volume, V max Indicates the maximum allowable volume of the HUD system, R current Indicates the resolution of the current real image, R max Indicates the ideal maximum resolution of a real image.

8. The internal projection large field of view HUD system according to any one of claims 1 to 3, characterized in that: The reflective imaging component (2) comprises a first reflector (21) and a second reflector (22) for reflecting a light beam (3); at least one of the first reflector (21) and the second reflector (22) is also used for converging the light beam (3); the first reflector (21) is located in the light emitting direction of the image source (1); the second reflector (22) is located in the light beam (3) reflecting direction of the first reflector (21); the light beam (3) emitted by the image source (1) is reflected and converged by the first reflector (21) and the second reflector (22), and then emitted by the second reflector (22) to form the real image.

9. The internal projection large field of view HUD system according to claim 8, characterized in that: The surface formulas of the first reflector (21) and the second reflector (22) are: Among them, r 2 =x 2 +y 2 , z represents the sagittal height difference in the Z-axis direction, c represents the curvature, k represents the conic surface constant, and m and n represent the orders of x and y respectively.

10. The internal projection large field of view HUD system according to any one of claims 1 to 3, characterized in that: The diffusion film (4) is located at the position of the vehicle's onboard instrument panel and / or the central control display screen.

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