Projection lens and vehicle-mounted head-up display system

Abstract

A projection lens and a vehicle-mounted head-up display system, comprising: a front projection objective lens group, a diaphragm (8) and a rear projection objective lens group which are sequentially arranged from an object surface to an image surface and are coaxially arranged. The front projection objective lens group comprises: a first negative lens (1), a first positive lens (2) and a second negative lens (3) which are sequentially arranged from the object surface to the diaphragm and are coaxially arranged; the first negative lens (1) and the second negative lens (3) are meniscus concave lenses, the concave surface of the first negative lens (1) facing the first positive lens (2), and the concave surface of the second negative lens (3) facing the diaphragm (8). The rear projection objective lens group comprises: a third negative lens (4), a second positive lens (5) and a third positive lens (6) which are sequentially arranged from the diaphragm to the image surface and are coaxially arranged. In the present technical solution, the projection of an image to be projected can be completed using only six lenses. Compared with the prior art, due to the small number of lenses, the number of surfaces where lens glass is in contact with the air is less, which greatly reduces light energy loss and greatly increases light transmission efficiency; in addition, as the number of lenses is small, the cost is also correspondingly reduced.

Description

A projection lens and vehicle head-up display system

[0001] This application claims priority to the following Chinese patent applications filed on January 26, 2025, with application number 202510122778.8, entitled "A Human-Computer Interaction System and Automobile Integrating ARHUD and Holographic Instrument", filed on January 26, 2024, with application number 202520174538.8, entitled "A Dual Head-Up Display Fusion Imaging System and Automobile", and filed on September 4, 2025, with application number 202511261906.3, entitled "A Projection Lens and Vehicle Head-Up Display System", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to the field of optical projection imaging technology, and in particular to a projection lens and a vehicle head-up display system. Background Technology

[0003] A vehicle-mounted HUD (Head-Up Display) imaging system is a technology that projects vehicle information onto the windshield or a separate transparent screen directly in front of the driver. Drivers do not need to look down at the information displayed on visual terminals such as mobile phone navigation, car instrument panel, and car center console screen, making it easier to concentrate on driving and reducing the probability of road traffic accidents.

[0004] In existing vehicle-mounted HUD imaging systems, the PGU (Picture Generation Unit) system is very complex, and the existing PGU projection lens has a large number of lenses, resulting in low light transmission efficiency. Summary of the Invention

[0005] In view of this, the present invention provides a projection lens that improves light transmission efficiency while reducing costs.

[0006] The present invention also provides a vehicle head-up display system including the above-described projection lens.

[0007] As can be seen from the above technical solution, the projection lens provided by the present invention can complete the projection of the image to be projected by using only six lenses. Compared with the prior art, due to the small number of lenses, the number of surfaces of the lens glass in contact with the air is small, the light energy loss is greatly reduced, the light transmission efficiency is greatly increased, and the cost is also reduced accordingly due to the small number of lenses.

[0008] The present invention also provides a vehicle head-up display system, which has corresponding beneficial effects due to the use of the above-mentioned projection lens, as can be seen from the previous description, and will not be repeated here. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 is a system diagram of Embodiment 1 of the vehicle-mounted projection lens of the present invention (excluding the object surface);

[0011] Figure 2 is a schematic diagram of Figure 1 after adding light;

[0012] Figure 3 is a system diagram (including object plane) of Embodiment 1 of the vehicle-mounted projection lens of the present invention;

[0013] Figure 4 is a schematic diagram of Figure 3 after adding light;

[0014] Figure 5 is a dot diagram of embodiment 1 of the vehicle-mounted projection lens of the present invention;

[0015] Figure 6 is a root mean square diagram of wavefront aberration of embodiment 1 of the vehicle-mounted projection lens of the present invention;

[0016] Figure 7 is a distortion diagram of Embodiment 1 of the vehicle-mounted projection lens of the present invention;

[0017] Figure 8 is an MTF curve diagram of embodiment 1 of the vehicle-mounted projection lens of the present invention;

[0018] Figure 9 is a system diagram of Embodiment 2 of the vehicle-mounted projection lens of the present invention (excluding the object surface);

[0019] Figure 10 is a schematic diagram of Figure 9 after adding light;

[0020] Figure 11 is a system diagram (including object plane) of Embodiment 2 of the vehicle-mounted projection lens of the present invention;

[0021] Figure 12 is a schematic diagram of Figure 11 after adding light;

[0022] Figure 13 is a dot diagram of embodiment 2 of the vehicle-mounted projection lens of the present invention;

[0023] Figure 14 is a root mean square diagram of wavefront aberration of embodiment 2 of the vehicle-mounted projection lens of the present invention;

[0024] Figure 15 is a distortion diagram of Embodiment 2 of the vehicle-mounted projection lens of the present invention;

[0025] Figure 16 is an MTF curve of embodiment 2 of the vehicle-mounted projection lens of the present invention;

[0026] Figure 17 is a schematic diagram of the cooperation between the lighting part and the projection lens of a head-up display system according to an embodiment of this application;

[0027] Figure 18 is a schematic diagram of the structure of a first embodiment of a head-up display system provided in this application;

[0028] Figure 19 is a schematic diagram of the structure of a second embodiment of a head-up display system provided in this application;

[0029] Figure 20 is a schematic diagram of the structure of a third embodiment of a head-up display system provided in this application;

[0030] Figure 21 is a structural schematic diagram of a fourth embodiment of a head-up display system provided in this application;

[0031] Figure 22 is a structural schematic diagram of a fifth embodiment of a head-up display system provided in this application;

[0032] Figure 23 is a schematic diagram of the X-direction component of image light in a fifth embodiment of a head-up display system provided in this application;

[0033] Figure 24 is a schematic diagram of the Y-direction component of image light in a fifth embodiment of a head-up display system provided in this application;

[0034] Figure 25 is a partial perspective view of a fifth embodiment of a head-up display system provided in this application.

[0035] The meanings of the various labels in the figure are as follows: 1 is the first negative lens, 2 is the first positive lens, 3 is the second negative lens, 4 is the third negative lens, 5 is the second positive lens, 6 is the third positive lens, 7 is the prism, 8 is the aperture stop, 9 is the object plane, 13 is the image plane, 14 is the DMD glass cover plate; 10 is the image generation unit, 20 is the diffusion element, 11 is the near-field diffusion sub-element, 12 is the far-field diffusion sub-element, 30 is the mirror assembly, 31 is the first mirror, 32 is the second mirror, 33 is the third mirror, 40 is the holographic optical element; 50 is the reflection assembly, 51 is the first mirror, 52 is the second mirror, 53 is the light deflection element; 60 is the intermediate image plane. Detailed Implementation

[0036] The following provides explanations for some of the terms used in this plan:

[0037] Dot plots are one of the most commonly used evaluation methods in modern optical design. The smaller the dot plot, the smaller the spot size of the optical system and the smaller the aberrations of the system.

[0038] The root mean square (RMS) of wavefront aberration is a method for quantifying the imaging quality of an optical system. It is the square root of the average of the squares of all wavefront errors in the optical system. Wavefront errors can be caused by a variety of factors, including deviations in the lens surface, non-ideal shapes of optical elements, and scattering by optical materials. The RMS of wavefront aberration can be used to evaluate the resolution and imaging quality of an optical system.

[0039] Field curvature: Also known as image field curvature, when a planar object passes through a lens system, the image plane formed by focusing all planar object points does not coincide with the ideal image plane, but is instead a curved surface. The vertical axis of field curvature / distortion is the field of view angle. Generally, a lens with field curvature controlled to within 100 micrometers is considered a good lens.

[0040] For automotive projection lenses, the most important imaging quality indicator is MTF (Mean Transfer Function). The design value of the imaging quality of projection lenses is not satisfactory. When the optical transfer function (MTF) characterizes the imaging quality, the MTF value of projection lenses is usually less than 0.3 at 50 line pairs per millimeter. In subsequent processing and assembly, errors such as material refractive index error, optical surface curvature radius error, and fit error between optical lenses and mechanical barrels are introduced. These errors usually reduce the MTF by 20%, which means that the MTF can usually only reach 0.24. In principle, such imaging quality is insufficient to meet the sharpness requirements in use.

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] The projection lens provided in this embodiment of the invention is applied to an in-vehicle head-up display system, as shown in Figure 1, including: a front group of projection lenses, an aperture 8, and a rear group of projection lenses arranged coaxially from the object plane 9 to the image plane 13.

[0043] As shown in Figures 1 and 7, the front group of the projection lens includes: a first negative lens 1, a first positive lens 2, and a second negative lens 3 arranged coaxially from the object plane 9 to the aperture stop 8; wherein, the first negative lens 1 and the second negative lens 3 are meniscus concave lenses, and the concave surface of the first negative lens 1 faces the first positive lens 2, and the concave surface of the second negative lens 3 faces the aperture stop 8. Alternatively, the convex surface of the first negative lens 1 faces the object plane 9, and the convex surface of the second negative lens 3 faces the first positive lens 2.

[0044] The rear group of the projection lens includes a third negative lens 4, a second positive lens 5, and a third positive lens 6 arranged coaxially from the aperture stop 8 to the image plane 13. As shown in Figures 1 and 9, the third negative lens 4 and the second positive lens 5 are cemented together to form a cemented lens, which allows for rapid assembly of the projection lens and reduces reflection and energy loss during refraction. As shown in Figures 1 and 9, a prism 7 is provided between the third positive lens 6 and the image plane 13 to distribute light. Furthermore, the prism 7 is a standard component for ease of manufacturing.

[0045] In the above technical solution, the image to be projected is formed on the image plane 13, and is sequentially projected onto the object plane 9 through the third positive lens 6, the second positive lens 5, the third negative lens 4, the aperture 8, the second negative lens 3, the first positive lens 2, and the first negative lens 1. The image propagation path can be seen in Figures 4 and 12. This technical solution utilizes only six lenses to project the image. Compared with existing technologies, due to the smaller number of lenses, the number of surfaces of the lens glass in contact with air is reduced, significantly reducing light energy loss and increasing light transmission efficiency. Furthermore, the cost is correspondingly reduced due to the smaller number of lenses.

[0046] In an optional technical solution, as shown in Figures 1 and 9, a DMD glass cover plate 14 is disposed on the DMD chip between the prism 7 and the image plane 13. The DMD glass cover plate 14 on the DMD chip mainly serves a protective function, preventing dust and other contaminants from entering the gaps and causing pixel failure; it can also isolate moisture, oxygen, etc., extending the life of the DMD chip. In addition, the presence of the DMD glass cover plate 14 ensures that when the micromirror is flipped, the inner surface of the DMD glass cover plate 14 maintains a sufficient safe distance from the top of the micromirror to prevent contact.

[0047] By optimizing the above technical solution, the DMD glass cover 14 is made of EAGLEXG material (i.e., high-performance alkali-free borosilicate glass), which makes the DMD glass cover 14 have high light transmittance and ensures that the display screen is clear and bright.

[0048] In one alternative technical solution, the first negative lens 1, the second negative lens 3, and the third negative lens 4 are made of H-ZF52 material. H-ZF52 material is an optical glass with high refractive index and low dispersion, which can meet the projection requirements; H-ZF52 material is a type of heavy flint glass. Furthermore, since the first negative lens 1, the second negative lens 3, and the third negative lens 4 are made of H-ZF52 material, projection scattering can be reduced, image sharpness can be improved, color reproduction can be optimized, and light loss can be reduced.

[0049] The first positive lens 2 and the third positive lens 6 are made of H-LAK3 material. H-LAK3 material has a high Abbe number, low dispersion, and stability, and possesses excellent mechanical properties (resistant to scratches and wear, ensuring lens surface precision), meeting projection requirements. H-LAK3 material is a type of lanthanum crown glass. Furthermore, the H-LAK3 material used in the first positive lens 2 and the third positive lens 6 avoids problems such as color edge shift, ensuring the accuracy and purity of the projected image's colors. It also exhibits excellent optical uniformity, guaranteeing the quality of the projected light and resulting in a more stable and clearer projected image.

[0050] The second positive lens 5 is made of H-ZK7 material, which has a high refractive index and low dispersion, meeting the requirements of projection. H-ZK7 is a type of crown glass. Furthermore, using H-ZK7 material to make the second positive lens 5 reduces dispersion interference, improves image sharpness, and thus restores clear colors in the projection. The physical and chemical properties of H-ZK7 also enhance the long-term stability of the projection device and reduce maintenance costs.

[0051] In one alternative technical solution, the first negative lens 1 and the third negative lens 4 are made of H-ZF52 material. H-ZF52 material is an optical glass with high refractive index and low dispersion, which can meet the projection requirements. In addition, the first negative lens 1 and the third negative lens 4 made of H-ZF52 material can reduce projection scattering, improve image sharpness, optimize color reproduction, and reduce light loss.

[0052] The first positive lens 2 and the third positive lens 6 are made of H-LAK3 material. H-LAK3 material has a high Abbe number, low dispersion and stability, and good mechanical properties (resistant to scratches and wear, ensuring the surface accuracy of the lens) to meet the projection requirements.

[0053] The second negative lens 3 is made of H-ZF1 material, which has a high refractive index, high dispersion characteristics, and chemical stability. H-ZF1 material is a heavy flint glass. The second negative lens 3 made of H-ZF1 material helps to improve the clarity and sharpness of the projected image, making the projected images and text clearer and more legible. At the same time, it can correct the chromatic aberration of the entire system, thereby making the colors of the projected image more accurate and pure, and avoiding problems such as color edge shift.

[0054] The second positive lens 5 is made of H-K9L material, which possesses high optical performance, chemical stability, and process adaptability. H-K9L material is a colorless optical glass. Furthermore, the second positive lens 5, made of H-K9L material, ensures a sufficiently bright projected image, preventing dimming due to light loss. It also exhibits strong physical stability and resistance to wear and tear.

[0055] A vehicle-mounted head-up display (HUD) system, as shown in Figures 18-20, includes: an object surface 9 and the aforementioned projection lens; a diffuser element 20 is provided at the position of the object surface 9, the normal of the diffuser element 20 being set at an angle to the optical axis of the projection lens, as shown in Figure 3; preferably, the diffuser element 20 is a diffuser film. In this technical solution, the diffuser film ensures that stray sunlight rays incident on the diffuser film from the outer edge of the windshield imaging light path have a certain angle with the optical axis of the projection lens, preventing them from reaching the DMD image source surface and avoiding overlap between stray light and the image to be imaged, effectively avoiding the influence of stray light. Furthermore, the angled arrangement between the diffuser film and the optical axis of the projection lens serves two purposes: firstly, it reduces the reflected light rays from the projection lens incident on the diffuser film; secondly, it reduces the size of the HUD.

[0056] A vehicle-mounted head-up display system includes the aforementioned projection lens. As shown in Figure 1, the projected principal ray from the projection lens is set at an angle α to its optical axis, the angle α being in the range of 1.7-2.7 degrees. Preferably, the angle α is 1.7 degrees. The prism 7 is a triangular glass body, and its optical axis is an imaginary straight line representing the central axis of rotational symmetry of the optical system, as shown in Figure 17.

[0057] In one alternative technical solution, the image generation unit 10 may consist of two parts: an illumination section and a projection lens. The illumination section includes lamp beads, collimation components, and compound eyes, etc.

[0058] The technical features mentioned above, those to be mentioned below, and those shown individually in the accompanying drawings can be combined arbitrarily, provided that the combined technical features are not contradictory. All feasible combinations of features are the technical content explicitly described herein. Any one of the multiple sub-features contained in the same statement can be applied independently, without necessarily being applied together with other sub-features.

[0059] The following is a further description of this solution with reference to specific embodiments:

[0060] In Embodiment 1, as shown in Figures 1 and 3, the first negative lens 1, the second negative lens 3, and the third negative lens 4 are made of H-ZF52 glass; the first positive lens 2 and the third positive lens 6 are made of H-LAK3 glass; the second positive lens 5 is made of H-ZK7 glass; the aperture stop 8 is located between the second negative lens 3 and the third negative lens 4; and the prism 7 is made of EAGLEXG glass. The glass material between the surfaces of the first negative lens 1 and the first positive lens 2 is H-ZF52, which is the material of the entire first negative lens 1 (composed of surface 1 and surface 2); the space between surface 2 and surface 3 is air; and surface 3 and surface 4 constitute lens 2, which is made of H-LAK3 glass. The relationships between subsequent lenses and surface numbers follow the same pattern. The specific parameters of each component in this embodiment are shown in the table below.

[0061] As shown in Figure 5, in this embodiment, the geometric radius (maximum radius) of the entire optical system is less than 50 micrometers, which meets the system's requirements for aberrations.

[0062] As shown in Figure 6, in this embodiment, the root mean square of the wavefront difference is less than 0.5, indicating that the resolution and imaging quality of this embodiment meet the imaging requirements.

[0063] As shown in Figure 7, in this embodiment, the field curvature / distortion meets the imaging requirements of the optical system.

[0064] As shown in Figure 8, in this embodiment, at a sampling frequency of 50 line pairs / mm, the MTF value of the entire field of view exceeds 0.4. This indicates that the imaging quality of this embodiment is sufficient to meet the imaging quality requirements.

[0065] In Embodiment 2, as shown in Figures 9 and 12, the first negative lens 1 and the third negative lens 4 are H-ZF52 glass lenses, the first positive lens 2 and the third positive lens 6 are H-LAK3 glass lenses, the second negative lens 3 is an H-ZF1 glass lens, the second positive lens 5 is an H-K9L glass lens, and the aperture stop 8 is located between the second negative lens 3 and the third negative lens 4. The prism 7 is made of EAGLEXG glass. The specific parameters of each component in this embodiment are shown in the table below.

[0066] As shown in Figure 13, in this embodiment, the geometric radius (maximum radius) of the entire optical system is less than 50 micrometers, which meets the system's requirements for aberrations.

[0067] As shown in Figure 14, in this embodiment, the root mean square of the wavefront difference is less than 0.5, indicating that the resolution and imaging quality of this embodiment meet the imaging requirements.

[0068] As shown in Figure 15, in this embodiment, the field curvature / distortion meets the imaging requirements of the optical system.

[0069] As shown in Figure 16, in this embodiment, at a sampling frequency of 50 line pairs / mm, the MTF value of the entire field of view exceeds 0.4. This indicates that the imaging quality of this embodiment is sufficient to meet the imaging quality requirements.

[0070] Technical advantages of this projection lens:

[0071] 1. PGU projection lenses (i.e., projection lenses) have fewer lenses, higher light transmission efficiency, and lower cost. Because of the fewer lenses, the number of surfaces of the lens glass in contact with air is less, which greatly reduces light energy loss and increases light transmission efficiency. At the same time, the cost is also reduced accordingly due to the fewer lenses.

[0072] Second, PGU projection lenses use fewer types of glass, resulting in fewer sources of error during design and manufacturing, and easier control over image quality. In contrast, this invention patent uses only three or four types of glass. These are all very common types of glass, produced by glass factories with extensive and mature manufacturing processes. Therefore, the physicochemical properties of these glasses are far superior to those of rarer, more exotic glasses, especially in terms of refractive index error, which is very small and closely matches the refractive index used in the software. This minimizes sources of error and makes image quality easier to control.

[0073] Third, the patented PGU projection lens employs a technical solution where the diffuser film and the projection lens optical axis have a certain angle. During use, backlighting will not cause stray light to overlap with the actual image to be imaged, thus not affecting the image viewing effect. This ensures that stray sunlight rays incident on the diffuser film from the outer edge of the windshield's imaging path have a certain angle with the projection lens optical axis, preventing them from reaching the DMD image source surface and thus avoiding the overlap of stray light with the image to be imaged, effectively preventing the influence of stray light.

[0074] Fourth, PGU projection lenses all use a spherical surface, which is easy to manufacture, not difficult to process, reduces costs, and the image quality does not deteriorate with temperature changes. In contrast, this invention patent uses glass entirely, and all of them are spherical lenses. The processing technology is simple, the testing technology is mature, and the assembly and adjustment are also easy. At the same time, glass is not sensitive to temperature, the spherical surface does not change with temperature, and temperature changes will not affect the image quality.

[0075] Fifth, the patented PGU projection lens delivers high image quality, ensuring compliance with usage requirements. This patented invention underwent repeated optimization during design, achieving an MTF design value exceeding 0.4 at 50 line pairs per millimeter, even with a limited number of lenses and glass types. Even considering subsequent errors, the final MTF value reaches 0.32, which is sufficient to meet usage requirements.

[0076] VI. The invention patent takes into account the angle between the emitted principal ray and the optical axis. The angle between the emitted principal ray and the optical axis of the designed PGU projection lens is less than 2.7°, much less than 15°. Thus, since the DMD image source is a Lambertian radiator, the closer to the optical axis, the higher the radiated energy. Therefore, this invention patent maximizes the utilization of the radiated energy of the DMD.

[0077] In one specific embodiment, referring to Figures 18 and 19, a human-computer interaction system (i.e., a head-up display system) integrating ARHUD and holographic instruments disclosed in this application includes: an image generation unit 10, a diffusion element 20, a reflector assembly 30, and a holographic optical element 40; wherein, the image generation unit 10 includes, but is not limited to, the aforementioned projection lens. The projection lens has the following advantages: first, fewer lenses, higher light transmission efficiency, and lower cost; second, fewer types of glass are used in the PGU projection lens, resulting in fewer sources of error during the design and manufacturing of the PGU projection lens, and easier control of image quality; third, all projection lenses adopt a spherical surface shape, which has good manufacturability; and fourth, the projection lens has high image quality, which can guarantee the requirements for use.

[0078] The image generation unit 10 is used to generate a target beam, which includes a first beam and a second beam. The first beam carries close-up image information, and the second beam carries distant image information. The content of the image information carried by the first beam and the second beam is different. The image generation unit 10 can generate two beams carrying different projection information through its internal optical elements and imaging technology. For example, one beam carries type A projection information, and the other beam carries type B projection information.

[0079] Referring to Figure 18, the diffusion element 20 achieves uniform light diffusion by reflecting and refracting the incident light multiple times through its internal microstructure. In this scheme, the diffusion element 20 is disposed on the transmission path of the second beam to diffuse it. To ensure that the second beam is clearly and accurately presented in the driver's field of vision, the projected second beam needs to be diffused and homogenized. After diffusion, the second beam is projected as a virtual image at the second position, which can display the projection data more clearly and three-dimensionally.

[0080] Referring to Figure 18, the reflector assembly 30 is an optical component, mainly composed of a reflector and a package. In this solution, the reflector assembly 30 is used to project the target beam onto a corresponding target position. The target beam consists of the first beam and the second beam, which cannot be directly projected onto the corresponding target position. The target position includes a first position where the holographic optical element 40 is located on the windshield, and a second position on the windshield. The coordinates of the first position and the second position are different on the windshield. In this solution, the reflector assembly 30 is at least used to reflect the second beam to the second position. The second beam projected onto the second position will form a distant image on the windshield. The first beam can be projected onto the first position after being reflected by the reflector assembly 30, or it can be directly projected onto the first position without being reflected by the reflector assembly 30.

[0081] Referring to Figure 18, the holographic optical element 40 (HOE) is an optical element made according to the principle of holography, usually fabricated on a photosensitive thin film material. Its function is based on the principle of light diffraction, making it a diffractive optical element. In this embodiment, the holographic optical element 40 is used to diffract the first light beam to form a close-up image on the windshield.

[0082] Referring to Figure 18, in the imaging process of the human-computer interaction system that integrates ARHUD and holographic instruments disclosed in this application, the image generation unit 10 generates a first beam and a second beam carrying different projection information. Then, a diffusion element 20 diffuses and homogenizes the second beam. A reflector assembly 30 projects the first beam and the second beam to a first position and a second position, respectively. The first beam projected at the first position undergoes diffraction under the action of the holographic optical element 40, forming a real HOE image on the windshield (a real HOE image refers to a real image generated by a holographic optical element). The projection information carried by the first beam is displayed through this HOE image. The second beam projected at the second position forms a distant virtual image on the windshield, and the projection information carried by the second beam is displayed through this distant image. This human-computer interaction system integrating ARHUD and holographic instruments only requires one holographic optical element and one optical transmission system to complete the display of two projection information streams. The human-computer interaction system integrating ARHUD and holographic instruments has a simple structure and smaller size.

[0083] Referring to Figure 18, in the technical solution disclosed in this embodiment, the type of the image generation unit 10 can be selected according to design requirements. For example, the image generation unit 10 can be any one of DLP, LCOS, LBS, or Micro LED-based image generation units. Digital Light Processing (DLP) technology is a projection technology based on a Digital Micromirror Device (DMD). A DMD chip is an optical microelectromechanical system capable of spatial light modulation, containing millions of tiny aluminum mirrors, each corresponding to a pixel. The number of mirrors determines the display resolution. Liquid Crystal on Silicon (LCOS) technology is a novel display technology combining the advantages of LCD (Liquid Crystal Display) and DLP (Digital Light Processing). The image generation unit (PGU) based on Laser Beam Scanning (LBS) technology is one of the core components of a HUD (Head-Up Display) system. Of course, the above-mentioned types of image generation units are only examples in this application. When designing, users can also choose other types of image generation units according to their own design needs.

[0084] Referring to Figure 18, in this embodiment, to ensure that the first beam and the second beam generated by the image generation unit 10 do not interfere with or confuse each other, the image generation unit 10 may include a first display area and a second display area. The first display area is used to generate the first beam, and the second display area is used to generate the second beam. The exit angles of the beams generated by the image generation unit 10 may be different, so that the beams separate from each other after exiting, which facilitates the arrangement of the diffuser element 20 and the reflector assembly 30.

[0085] Referring to Figure 18, in the technical solution disclosed in this embodiment, the specific type of the diffusion element 20 can be selected according to the design requirements. It can be any diffusion film known in the existing solutions that can meet the diffusion requirements in this solution. For example, it can be a gradient diffusion film or a deflection diffusion film.

[0086] Referring to Figure 18, in the technical solution disclosed in this embodiment, the specific structure of the reflector assembly 30 can be arranged according to the incident direction of the light beam to be intervened and its corresponding target position. In this embodiment, the reflector assembly 30 may include at least one reflector group, each reflector group corresponding to a different light beam, and the reflector group is used to reflect the incident light beam corresponding to the reflector group to the target position corresponding to the light beam.

[0087] For example, referring to Figure 18, the reflector assembly 30 includes a first reflector group, comprising a first reflector 31 and a second reflector 32. The first reflector 31 and the second reflector 32 are arranged opposite to each other to reflect the incident second beam to its corresponding second position. When using the first reflector 31 and the second reflector 32 to correct the optical path of the second beam, the positions and angles of the first reflector and the second reflector can be arranged according to the incident angle of the second beam and its corresponding second position.

[0088] In this embodiment, referring to Figure 18, the type of reflector in the reflector assembly 30 can be set according to the reflection requirements. The reflector can be a plane mirror or a curved mirror. For example, in the embodiment shown in Figure 18, the first reflector can be a plane mirror or a curved mirror, and the second reflector is a curved mirror.

[0089] In this embodiment, referring to Figure 18, the reflector group may further include a second reflector group, which is used to reflect the first beam to its corresponding first position. In the technical solution disclosed in this embodiment, when it is necessary to use the reflector assembly 30 to correct the path of the first beam so that the first beam falls at the first position, a second reflector group for path correction of the first beam needs to be set in the reflector assembly 30. The number and distribution of the reflectors in the reflector group can be determined based on the incident angle of the first beam and the first position. For example, in the example of Figure 19, only one reflector is needed to reflect the first beam to the first position. Therefore, the second reflector group may include only one reflector, denoted as the third reflector 33. The third reflector 33 is used to reflect the incident beam to the first position. The third reflector can be a plane mirror, and the reflection angle of the third reflector can be determined based on the incident angle of the first beam and the specific position of the first position.

[0090] In the technical solution disclosed in this embodiment, referring to Figure 18, the projection information carried by the first beam and the second beam can be determined according to the relevant requirements. Users can independently adjust the specific content of the projection information carried by the first beam and the second beam generated by the image generation unit 10 through system control according to their own needs. For example, in this embodiment, the projection information carried by the first beam includes vehicle status information, and the information carried by the second beam includes non-vehicle status information. The vehicle status information includes at least instrument information, vehicle speed information, fuel level information, prompt information, and alarm information, or any combination of one or more of these; the non-vehicle status information includes at least navigation and positioning information, traffic safety warning information, smart office information, and entertainment information, or any combination of one or more of these.

[0091] In this embodiment, when the target user (in a car scenario, the target user can be the driver) views the projected images at the first and second positions, the target user may focus more on the data in a certain area of ​​the projected image. Furthermore, the user's adaptability to different brightness levels of the projected image varies depending on the ambient brightness. For example, in high ambient brightness, the brightness of the projected image needs to be increased, while in low ambient brightness, the brightness needs to be decreased. To achieve the eye-tracking function of the projected images at the first and second positions and the adaptive brightness adjustment function, the human-computer interaction system fused with ARHUD and holographic instrumentation disclosed in this embodiment may further include a photoelectric control module. This photoelectric control module is used to implement the eye-tracking function of the projected images at the first and second positions and the adaptive brightness adjustment function. In this case, the human-computer interaction system fused with ARHUD and holographic instrumentation can automatically adjust the projected images at the first and second positions according to the user's gaze, and automatically adjust the brightness of the projected images at the first and second positions, so that the projected images follow the user's gaze and automatically adjust their own brightness based on the ambient brightness.

[0092] In another specific embodiment, in order to solve the problems of complex structure and large system size of dual-optical-path HUD imaging system, this application provides a dual-head-up display fusion imaging system (i.e., head-up display system). The dual-head-up display fusion imaging system generates two beams carrying different projection information through an image generation unit. One beam is directly reflected through the windshield for display, and the other beam is displayed after passing through a holographic optical element. Thus, the optical path system only requires one holographic optical element and an optical transmission system, and has a simple structure and small size.

[0093] Referring to Figure 20, an embodiment of this application discloses a dual head-up display fusion imaging system, including: an image generation unit 10, a diffusion element 20, a reflector assembly 30, and a holographic optical element 40; wherein, the image generation unit 10 includes, but is not limited to, the aforementioned projection lens. The projection lens has the following advantages: first, fewer lenses, higher light transmission efficiency, and lower cost; second, fewer types of glass are used in the PGU projection lens, resulting in fewer sources of error during the design and manufacturing of the PGU projection lens, and easier control of image quality; third, all projection lenses adopt a spherical surface shape, which has good manufacturability; and fourth, the projection lens has high image quality, which can guarantee the requirements of use.

[0094] Referring to Figure 20, the image generation unit 10 is used to generate a target beam, which includes a first beam and a second beam. The first beam carries near-field image information, and the second beam carries far-field image information. The near-field image information and the far-field image information contain different data content. The image generation unit 10 can generate two beams carrying different projected image information through its internal optical elements and imaging technology. For example, one beam carries type A image information, and the other beam carries type B image information.

[0095] Referring to Figure 20, the diffusion element 20 includes a near-field diffusion sub-element 11 and a far-field diffusion sub-element 12. The near-field diffusion sub-element 11 is used to diffuse and homogenize the first beam, and the far-field diffusion sub-element 12 is used to diffuse and homogenize the second beam. In this scheme, the diffusion element 20 can diffuse and homogenize the beam emitted by the image generation unit 10 to improve the visibility and readability of the projected image.

[0096] Referring to Figure 20, the reflector assembly is an optical component, mainly composed of a reflector and a package. In this scheme, the reflector assembly 30 is used to project the diffused target beam onto a corresponding target position. The target position includes a first position on the windshield where the holographic optical element 40 is located, and a second position on the windshield. The coordinates of the first and second positions on the windshield are different. In this scheme, the reflector assembly 30 reflects the desired beam. The first beam, projected onto the first position directly or after correction by the reflector assembly, undergoes diffraction under the action of the holographic optical element 40, thus forming a near-field image. The second beam, after correction by the reflector assembly and projected onto the second position, forms a far-field image on the windshield, thereby completing the projection of both images.

[0097] Referring to Figure 20, holographic optical elements (HOEs) are optical elements made according to the principles of holography, typically fabricated on photosensitive thin film materials. Their function is based on the principle of light diffraction to form projected images. In this embodiment, the holographic optical element 40 is used to diffract the first light beam to form a close-up image.

[0098] Referring to Figure 20, the dual head-up display fusion imaging system disclosed in this application generates a first beam and a second beam carrying different projection information through an image generation unit 10 during the imaging process. Then, a diffusion element 20 is used to uniformly diffuse the first and second beams, and a reflector assembly 30 is used to correct the beam paths. Ultimately, the first beam is projected to a first position, and the second beam is projected to a second position. The first beam projected at the first position undergoes diffraction under the action of the holographic optical element 40, forming a close-up image in front of the windshield. The projection information carried by the first beam is displayed through this close-up image. The second beam projected at the second position forms a distant image in front of the windshield, and the projection information carried by the second beam is displayed through this distant image. This dual head-up display fusion imaging system only requires one holographic optical element and one optical transmission system to complete the display of two projection information paths, resulting in a simple structure and smaller size.

[0099] Referring to Figure 20, in the technical solution disclosed in this embodiment, the type of the image generation unit 10 can be selected according to design requirements. For example, the image generation unit 10 can be any one of DLP, LCOS, LBS, or Micro LED-based image generation units. Digital Light Processing (DLP) technology is a projection technology based on a Digital Micromirror Device (DMD). A DMD chip is an optical microelectromechanical system capable of spatial light modulation, containing millions of tiny aluminum mirrors, each corresponding to a pixel. The number of mirrors determines the display resolution. Liquid Crystal on Silicon (LCOS) technology is a novel display technology combining the advantages of LCD (Liquid Crystal Display) and DLP (Digital Light Processing). The image generation unit (PGU) based on Laser Beam Scanning (LBS) technology is one of the core components of a HUD (Head-Up Display) system. Of course, the above-mentioned types of image generation units are only examples in this application. When designing, users can also choose other types of image generation units according to their own design needs.

[0100] In this embodiment, referring to FIG20, to ensure that the first beam and the second beam generated by the image generation unit 10 do not interfere with or confuse each other, the image generation unit 10 may include a first display area and a second display area. The first display area is used to generate the first beam, and the second display area is used to generate the second beam. The exit angles of the beams generated by the image generation unit 10 can be different, so that the beams separate from each other after exiting, which facilitates the arrangement of the diffuser element 20 and the reflector assembly 30.

[0101] In this embodiment, referring to Figure 20, the first sub-diffusing element and the second sub-diffusing element are independent packaging structures or combined integral packaging structures. When the first sub-diffusing element and the second sub-diffusing element are combined integrally packaged, the included angles between the first sub-diffusing element and the first beam, and between the second sub-diffusing element and the second beam, are matched to make the target beam clear image.

[0102] In the technical solution disclosed in this embodiment, referring to FIG20, the diffusion element 20 mainly achieves the diffusion of the light beam through its internal diffusion film. The specific type of diffusion film in the diffusion element 20 can be selected according to the design requirements. It can be any diffusion film known in the existing solutions that can meet the diffusion requirements of this solution. For example, it can be a gradient diffusion film or a deflection diffusion film.

[0103] In the technical solution disclosed in this embodiment, referring to Figure 20, the specific structure of the reflector assembly 30 can be arranged according to the number of beams to be intervened, the incident direction of these beams, and the target position corresponding to each beam. In this embodiment, the reflector assembly 30 may include at least one reflector group, each reflector group corresponding to a different beam, and the reflector group is used to reflect the incident beam corresponding to the reflector group to the target position corresponding to the beam.

[0104] For example, referring to Figure 20, the reflector assembly 30 includes a first reflector group, which includes a first reflector 31 and a second reflector 32. The first reflector 31 and the second reflector 32 are arranged opposite to each other to reflect the second light beam to its corresponding second position. When correcting the optical path of the second light beam, the positions and angles of the first reflector 31 and the second reflector 32 can be arranged according to the incident angle of the second light beam and its corresponding target position.

[0105] In this embodiment, referring to FIG20, the type of reflector in the reflector assembly 30 can be set according to the reflection requirements. The reflector can be a plane mirror or a curved mirror. For example, in the embodiment shown in FIG20, the first reflector can be a plane mirror or a curved mirror, and the second reflector can be a curved mirror.

[0106] In this embodiment, referring to Figure 20, the first beam can be directly projected to the first position after passing through the near-field diffuser element, or it can be projected to the first position after being reflected by the reflectors in the reflector assembly. In this case, the reflector assembly may also include a second reflector assembly, which is used to reflect the first beam to its corresponding first position. Similarly, the number and distribution of reflectors in the second reflector assembly can be determined based on the incident angle of the first beam and the first position. For example, in the example of Figure 21, only one third reflector 33 is needed to reflect the first beam to the first position. The third reflector can be a plane mirror, and the reflection angle of the third reflector can be determined based on the incident angle of the first beam and the specific location of the first position.

[0107] In the technical solution disclosed in this embodiment, referring to Figure 20, the projection information carried by the first beam and the second beam can be determined according to the relevant requirements. Users can independently adjust the specific content of the projection information carried by the first beam and the second beam generated by the image generation unit 10 through system control according to their own needs. For example, in this embodiment, the projection information carried by the first beam includes vehicle status information, and the information carried by the second beam includes non-vehicle status information. The vehicle status information includes at least instrument information, vehicle speed information, fuel level information, prompt information, and alarm information, or any combination of one or more of these; the non-vehicle status information includes at least navigation and positioning information, traffic safety warning information, smart office information, and entertainment information, or any combination of one or more of these.

[0108] Furthermore, this application also discloses a vehicle that can be equipped with the dual head-up display fusion imaging system described in any of the above embodiments.

[0109] As can be seen from the above solutions, referring to Figures 20 and 21, the dual head-up display fusion imaging system disclosed in this application, on the one hand, integrates the advantages of HOE and HUD, precisely controlling and guiding the projection light of the HOE optical path system to achieve efficient and high-resolution imaging in a relatively small space. The combination of the two allows for flexible design of the optical path according to the vehicle's interior space and shape, optimizing the interior space layout. On the other hand, different imaging methods can ensure the stability of near-field information while enhancing the experience of far-field depth information, improving the overall display effect, and creating a superior visual experience and information interaction platform for the driver.

[0110] In one alternative technical solution, as shown in Figures 22 and 25, an in-vehicle head-up display system includes: a projection lens (which may be the projection lens mentioned above, or other projection lenses different from those mentioned above); and also includes: a reflective component 50;

[0111] The reflector 50 is located on one side of the windshield 70 inside the vehicle. It is used to reflect the image light emitted from the projection lens to the windshield. The image light emitted from the projection lens passes through the reflector 50 in sequence and then forms a virtual image on the windshield 70. The driver sitting in the car can clearly see the information presented by the virtual image (such as vehicle speed, engine speed, power consumption, gear information, and other auxiliary function information) at the eye box position.

[0112] As shown in Figures 22 and 24, the reflective assembly 50 includes: a first reflector 51 and a second reflector 52 arranged in sequence.

[0113] Reflector 1 51 is used to reflect the image light emitted from the projection lens onto reflector 2 52, and reflector 2 52 is used to reflect the image light reflected by reflector 1 51 onto the windshield to form a virtual image;

[0114] Among them, the first reflector 51 is a concave mirror, so that the image light reflected by the first reflector 51 forms an intermediate image plane 60 on the path to the second reflector 52. The intermediate image plane 60 is the intermediate image plane of the Y-direction component of the image light.

[0115] As shown in Figure 22, the second reflector 52 is a concave mirror. The concave surfaces of the first reflector 51 and the second reflector 52 are arranged opposite to each other, which can reflect image light while further reducing the size of the vehicle head-up display system.

[0116] In the above technical solution, during use, the image light emitted from the projection lens passes sequentially through reflector 51 and reflector 52. Because reflector 51 is a concave mirror, the image light reflected from reflector 51 forms an intermediate image plane 60 on the path towards reflector 52. In simpler terms, the intermediate image plane 60 is where the image light reflected from reflector 51 converges near the focal point of reflector 51, causing the emitted image light to exchange positions relative to the image light on reflector 51 before reaching reflector 52. Specifically, reflector 51 has a large curvature along the Y-direction to form a concave surface in the Y-direction, allowing the Y-direction component of the light emitted from the projection lens to converge on the path towards reflector 52 (i.e., forming the intermediate image plane 60). This configuration provides more space below reflector 52 than traditional non-converging vehicle head-up display systems, allowing for a more compact arrangement of the diffuser film fixing structure and other components, further reducing the HUD's size.

[0117] As shown in Figures 22 and 24, the above technical solution is optimized by providing a light deflecting element 53 between the reflector 51 and the projection lens. The light deflecting element 53 causes the Y-direction component of the image light rays passing through it to converge (which can be understood as convergence along the length of a surface). This increases the overlap of the image light rays emitted from the projection lens on the reflector 51, reducing the size of the reflector 51 in the Y direction and thus compressing the HUD volume. It should be noted that the light deflecting element ensures that the exit angle of the image light rays passing through it matches the incident angle of the reflective component, primarily by deflecting the Y-direction component of the image light rays. Furthermore, the placement of the light deflecting element 53 further reduces the formation distance of the intermediate image plane 60 from the reflector 51, further compressing the gap between the reflector 51 and the second reflector 52, thereby making the vehicle head-up display system smaller.

[0118] In an optional technical solution, the light deflection element 53 includes: a Fresnel lens, a freeform surface lens, and a deflection gradient diffusion film sequentially disposed between the projection lens and the reflector 51;

[0119] The image light emitted from the projection lens passes sequentially through a Fresnel lens, a freeform lens, and a deflecting gradient diffuser. The Y-axis component of the image light is deflected and converges on the reflector 51. Specifically, the Fresnel lens, freeform lens, and deflecting gradient diffuser can be positioned near the shadow surface of the projection lens to achieve pupil matching of the Y-axis component and improve light efficiency. It should be noted that both the Fresnel lens and the freeform lens are positioned near the deflecting gradient diffuser and fixed using structural components. This allows for quick and easy fixation of the Fresnel lens and the freeform lens. In one embodiment, the Fresnel lens, freeform lens, and deflecting gradient diffuser are integrated into a single structure. This integrated structure improves optical efficiency, reduces light loss, simplifies production and assembly, and lowers overall costs.

[0120] In one alternative technical solution, the curvature of the concave freeform surfaces of reflector 51 and reflector 52 can be flexibly optimized and adjusted according to the automotive environment and customer parameter requirements.

[0121] In an optional technical solution, the image light emitted from the projection lens passes sequentially through the Fresnel lens, the freeform lens, and the deflecting gradient diffuser. The X-direction component of the image light is not deflected, causing it to diverge on the second reflector 52. As shown in Figure 23, when specifically used with the projection lens, the exit pupil of the projection lens is close to the X-direction entrance pupil of the image light, located near the aperture stop in the PGU lens. At this time, the X-direction component of the image light from the projection lens is divergent on the second reflector 52. It should be noted that the light deflection element 53 cannot converge the X-direction component of the image light from the projection lens.

[0122] It should be noted that in Figure 23, the X-direction entrance pupil is referenced to the image light emitted from the projection lens, and in Figure 24, the Y-direction entrance pupil is referenced to the image light transmitted through the light deflection element 53.

[0123] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0124] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A projection lens for use in a vehicle head-up display system, characterized in that, include: The front group of projection lenses, the aperture (8), and the rear group of projection lenses are arranged in sequence and coaxially from the object plane (9) to the image plane (13); The front group of the projection lens includes: a first negative lens (1), a first positive lens (2), and a second negative lens (3) arranged coaxially from the object surface (9) to the aperture stop (8); wherein the first negative lens (1) and the second negative lens (3) are meniscus concave lenses, and the concave surface of the first negative lens (1) faces the first positive lens (2), and the concave surface of the second negative lens (3) faces the aperture stop (8); The rear group of the projection lens includes: a third negative lens (4), a second positive lens (5) and a third positive lens (6) arranged coaxially from the aperture stop (8) to the image plane (13); the third negative lens (4) and the second positive lens (5) are cemented together to form a cemented lens; a prism (7) is provided between the third positive lens (6) and the image plane (13).

2. The projection lens according to claim 1, characterized in that, A DMD glass cover plate (14) is disposed on the DMD chip between the prism (7) and the image plane (13).

3. The projection lens according to claim 2, characterized in that, The DMD glass cover (14) is made of EAGLEXG material.

4. The projection lens according to any one of claims 1-3, characterized in that, The first negative lens (1), the second negative lens (3) and the third negative lens (4) are made of H-ZF52 material.

5. The projection lens according to any one of claims 1-3, characterized in that, The first positive lens (2) and the third positive lens (6) are made of H-LAK3 material.

6. The projection lens according to any one of claims 1-3 or 5, characterized in that, The second positive lens (5) is made of H-ZK7 material.

7. The projection lens according to any one of claims 1-3 or 6, characterized in that, The first negative lens (1) and the third negative lens (4) are made of H-ZF52 material.

8. The projection lens according to any one of claims 1-3, 5, or 7, characterized in that, The second negative lens (3) is made of H-ZF1 material.

9. The projection lens according to any one of claims 1-3, 5, or 7, characterized in that, The second positive lens (5) is made of H-K9L material.

10. The projection lens according to any one of claims 1-9, characterized in that, The first negative lens (1), the first positive lens (2), the second negative lens (3), the third negative lens (4), the second positive lens (5), and the third positive lens (6) are all spherical lenses.

11. A vehicle-mounted head-up display system, characterized in that, include: The object surface (9) and the projection lens as described in any one of claims 1-10; a diffusion element (20) is provided at the position of the object surface (9), and the normal of the diffusion element (20) and the optical axis of the projection lens are arranged at an angle.

12. A vehicle-mounted head-up display system, characterized in that, The projection lens includes any one of claims 1-10, wherein the emitted principal ray of the projection lens is set at an angle to its optical axis, and the angle ranges from 1.7 to 2.7 degrees.

13. A vehicle-mounted head-up display system, characterized in that, It includes an image generation unit (10), a diffusion element (20), and a reflector assembly (30), wherein the image generation unit (10) includes a projection lens as described in any one of claims 1-10; The image generation unit (10) is used to generate a first beam and a second beam, wherein the first beam carries close-up image information and the second beam carries distant image information. The diffusion element (20) is used to diffuse and homogenize the second beam; The reflector assembly (30) is used to reflect the first beam and / or the diffused second beam to a target position corresponding to the windshield, wherein the target position includes a first position located on the windshield where the holographic optical element (40) is located, and a second position located on the windshield; The first beam is diffracted at the first position of the windshield to form a real image, and the diffused second beam is reflected at the second position of the windshield to form a distant virtual image in front of the windshield. The image generation unit (10) is an image generation unit based on DLP / LCOS / LBS / Micro LED; The image generation unit (10) includes a first display area and a second display area, wherein the first display area is used to generate a first light beam and the second display area is used to generate a second light beam.

14. A vehicle-mounted head-up display system, characterized in that, It includes an image generation unit (10), a diffusion element (20), and a reflector assembly (30), wherein the image generation unit (10) includes a projection lens as described in any one of claims 1-10; The image generation unit (10) is used to generate a target beam, which includes a first beam and a second beam. The first beam carries close-up image information, and the second beam carries distant image information. The diffusion element (20) includes a near-field diffusion sub-element (11) and a far-field diffusion sub-element (12). The near-field diffusion sub-element (11) is used to diffuse and homogenize the first beam, and the far-field diffusion sub-element (12) is used to diffuse and homogenize the second beam. The reflector assembly (30) is used to reflect the diffused and homogenized target beam to the target position corresponding to the windshield, wherein the target position includes a first position where the holographic optical element (40) is located on the windshield, and a second position on the windshield; The first beam of light after diffusion and homogenization undergoes a diffraction effect at the first position, forming a near-field virtual image in front of the windshield; the second beam of light after diffusion and homogenization is reflected at the second position, forming a far-field virtual image in front of the windshield. The image generation unit (10) is an image generation unit based on DLP / LCOS / LBS / Micro LED; The image generation unit includes a first display area and a second display area, wherein the first display area is used to generate a first light beam and the second display area is used to generate a second light beam.

15. A vehicle-mounted head-up display system, characterized in that, Includes the projection lens as described in any one of claims 1-10; further includes: a reflective component (50); The reflective assembly (50) includes: a first reflector (51) and a second reflector (52) arranged in sequence; The first reflector (51) is used to reflect the image light emitted from the projection lens onto the second reflector (52), and the second reflector (52) is used to reflect the image light reflected by the first reflector (51) onto the windshield to form a virtual image; Among them, the first reflector (51) is a concave mirror, so that the image light reflected by the first reflector (51) forms an intermediate image plane (60) on the path toward the second reflector (52), and the intermediate image plane (60) is the intermediate image plane of the Y-direction component of the image light. The second reflector (52) is a concave mirror, and the concave surfaces of the first reflector (51) and the second reflector (52) are arranged opposite to each other.

16. The vehicle head-up display system according to claim 15, characterized in that, A light deflection element (53) is provided between the reflector (51) and the projection lens, the light deflection element (53) causing the Y-direction component of the image light passing through it to converge.

17. The vehicle head-up display system according to claim 16, characterized in that, The light deflection element (53) includes: a Fresnel lens, a freeform lens and a deflection gradient diffusion film sequentially disposed between the projection lens and the first reflector (51); The image light emitted from the projection lens passes sequentially through the Fresnel lens, the freeform lens, and the deflecting gradient diffusion film, and the Y-direction component of the image light is deflected and converges on the reflector (51).

18. The vehicle head-up display system according to claim 17, characterized in that, The Fresnel lens and the freeform lens are fixed by structural components.

19. The vehicle head-up display system according to claim 17, characterized in that, The Fresnel lens, the freeform lens, and the deflecting gradient diffusion film are an integrated structure.

20. The vehicle head-up display system according to claim 17, characterized in that, The image light emitted from the projection lens passes sequentially through the Fresnel lens, the freeform lens, and the deflecting gradient diffusion film, so that the X-direction component of the image light does not deflect, thereby causing the X-direction component of the image light to diverge on the second reflector (52).

Images