Display module and head-up display system

Abstract

The embodiment of the invention provides a display module and a head-up display system. The method comprises a first light source assembly, a second light source assembly, a free-form surface mirror and a reflection assembly. Wherein the first light source assembly is used for emitting a close-range light source to the free-form surface mirror; the second light source assembly is used for emitting a long-range light source to the free-form mirror; the free-form surface mirror comprises a semi-transmitting and semi-reflecting coating area and a mirror surface reflecting surface area, and the semi-transmitting and semi-reflecting coating area is used for refracting the close-shot light source to enable the close-shot light source to be incident to the reflecting assembly; the mirror reflection surface area is used for reflecting a long-range light source, so that the long-range light source enters the reflection assembly; and the reflection assembly is used for adjusting the reflection angle of the close-range light source and / or the long-range light source, and projecting the close-range light source and the long-range light source after the reflection angle is adjusted to a projection surface. The display module can achieve the effect of reducing the size of the display module.

Description

Technical Field

[0001] This application relates to the field of vehicle display technology, and more particularly to a display module and a head-up display system. Background Technology

[0002] With the rapid development of augmented reality (AR) and near-eye display (NED) technologies, optical display systems, as core components, have become a focus of industry attention due to their miniaturization, lightweight design, and high imaging quality. The dual PGU (Picture Generation Unit) architecture, due to its advantages such as higher brightness, redundancy backup, and heterogeneous image fusion, is widely used in high-end AR glasses, automotive head-up displays (HUDs), and other scenarios.

[0003] In the prior art, the optical path of dual PGU plus multiplexed plane mirror usually includes two independent image sources, which emit beams carrying different information or used to enhance brightness. The two beams are guided to the same optical axis by a series of plane mirrors and finally coupled into imaging modules such as waveguides or freeform prisms.

[0004] However, in order to avoid beam obstruction and crosstalk, each reflector needs to be precisely positioned at a specific angle and location, which often results in multiple folds in the optical path, thus causing the in-vehicle head-up display to occupy a large space. Summary of the Invention

[0005] The display module and head-up display system provided in this application embodiment are used to reduce the size of the display module.

[0006] In a first aspect, embodiments of this application provide a display module, including a first light source assembly, a second light source assembly, a freeform mirror, and a reflection assembly; wherein:

[0007] The first light source assembly is used to emit a near-field light source to the freeform mirror;

[0008] The second light source assembly is used to emit a distant light source to the freeform mirror;

[0009] The freeform mirror includes a semi-transparent and semi-reflective coating area and a mirror reflective surface area. The semi-transparent and semi-reflective coating area is used to refract near-field light sources so that the near-field light sources are incident on the reflective component. The mirror reflective surface area is used to reflect far-field light sources so that the far-field light sources are incident on the reflective component.

[0010] A reflective component is used to adjust the reflection angle of a near-field light source and / or a far-field light source, and to project the near-field light source and the far-field light source after adjusting the reflection angle onto the projection surface, respectively.

[0011] In one possible implementation, the radius of curvature of the freeform mirror satisfies at least one of the following conditions:

[0012] The radius of curvature of the semi-transparent and semi-reflective coating area is 500mm-3500mm;

[0013] The radius of curvature of the mirror-reflecting surface area is 2000mm-3000mm.

[0014] In one possible implementation, when the difference in the radius of curvature between the semi-transparent and semi-reflective coating area and the mirror reflective surface area is less than or equal to 500 mm, the semi-transparent and semi-reflective coating area and the mirror reflective surface area are integrally formed.

[0015] When the difference in the radius of curvature between the semi-transparent and semi-reflective coating area and the mirror reflective surface area is greater than 500mm, the semi-transparent and semi-reflective coating area and the mirror reflective surface area are set separately.

[0016] In one possible implementation, the reflective assembly includes a first reflector and a second reflector, which are respectively connected to an adjustment mechanism.

[0017] The first reflector is used to reflect a distant light source onto the projection surface at a first preset angle.

[0018] The second reflector is used to reflect the near-field light source to the projection surface at a second preset angle.

[0019] In one possible implementation, an adjustment mechanism is used to acquire the optical path offset and adjust the tilt angle of the first reflector and / or the tilt angle of the second reflector according to the optical path offset; the optical path offset characterizes the offset of the reflecting assembly from reflecting the near-field light source and / or the far-field light source to the projection surface.

[0020] In one possible implementation, the freeform mirror and the reflecting component satisfy at least one of the following conditions:

[0021] The length ratio of the semi-transparent, semi-reflective coating area to the length of the first reflective element is 1.6 to 1.8;

[0022] The width ratio of the semi-transparent and semi-reflective coating area to the width of the first reflective element is 1.5 to 1.7;

[0023] The ratio of the radius of curvature of the semi-transparent and semi-reflective coating area to that of the first reflective element is 0.75 to 0.85;

[0024] The length ratio of the mirror-reflecting surface area to the second reflector is 1.6 to 1.8;

[0025] The width ratio of the mirror-reflecting surface area to the width of the second reflector is 1.1 to 1.2;

[0026] The ratio of the radius of curvature of the mirror-reflecting surface area to that of the second reflector is 1.25 to 1.35.

[0027] In one possible implementation, an infrared cutoff coating is provided on the reflective surface of the first reflector and / or the reflective surface of the second reflector.

[0028] The semi-transparent and semi-reflective coating region includes at least one of the following: a high-reflectivity film, an infrared cutoff film, and an anti-reflection film.

[0029] In one possible implementation, the first light source assembly is disposed above the freeform mirror, the second light source assembly and the reflection assembly are disposed below the freeform mirror, and the reflection assembly is disposed closer to the projection surface than the second light source assembly.

[0030] The first and second reflectors in the reflective assembly are stacked one on top of the other.

[0031] In one possible implementation, the first light source assembly includes a first light source element and a specular reflector element, wherein a polarization selection film is provided on the reflective surface of the specular reflector element;

[0032] The first light source is used to emit a near-field light source to the mirror reflector;

[0033] A specular reflector is used to reflect a specular reflector onto a freeform mirror.

[0034] Secondly, embodiments of this application provide a head-up display system, including a display module.

[0035] The display module and head-up display system provided in this application embodiment, by setting a semi-transparent and semi-reflective coating area and a specular reflective surface area on a freeform mirror, respectively adapts to the imaging requirements of near-field and far-field light sources, avoiding optical distortion caused by a uniform curvature design. Simultaneously, the semi-transparent and semi-reflective coating merges the two light paths into the same output path, reducing the use of redundant optical components (such as independent plane mirrors or freeform mirrors). Furthermore, the reflective components ensure that the light paths of the semi-transparent and semi-reflective coating area and the specular reflective surface area do not overlap or interfere after merging, thereby improving image quality consistency while maintaining the same performance. Therefore, while meeting display requirements, the size can be reduced, thus adapting to the compact design requirements of automotive front cabins and avoiding increased assembly complexity and cost due to redundant components. Attached Figure Description

[0036] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0037] Figure 1 This is a schematic diagram of the structure of the display module provided in the embodiments of this application;

[0038] Figure 2 This is a schematic diagram of the optical path of the display module provided in this application.

[0039] 110 - First light source assembly; 111 - First light source element; 112 - Specular reflector; 120 - Second light source assembly; 130 - Freeform mirror; 131 - Semi-transparent and semi-reflective coating area; 132 - Specular reflective surface area; 140 - Reflection assembly; 141 - First reflector; 142 - Second reflector; 150 - Projection surface;

[0040] 210-Close-up PGU; 220-Distant-up PGU; 230-Plane mirror; 240-Curved mirror; 241-Region 1; 242-Region 2; 250-First freeform surface mirror; 260-Second freeform surface mirror; 270-Windshield.

[0041] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0042] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0043] First, let me explain the terms used in this application:

[0044] A head-up display (HUD) is a technology that projects key information (such as vehicle speed, navigation, and warning signals) into the driver's field of vision using optical projection. This allows the driver to obtain necessary data without looking down at the instrument panel, thereby reducing eye movement and improving driving focus and safety. Its core principle is to use optical elements such as mirrors, freeform mirrors, or waveguides to project light emitted from an image source onto the windshield or a dedicated transparent screen, forming a virtual image at a distance and achieving an intuitive fusion of information and the real road scene.

[0045] The Picture Generation Unit (PGU) is the core imaging module in a head-up display (HUD) or near-eye display system, responsible for generating and outputting the raw image beam. It can consist of a microdisplay (such as DLP, LCoS, or Micro-OLED), an illumination source, and driving circuitry. It converts digital image information into an optical image, which is then projected onto a virtual image visible to the human eye via a subsequent optical system (such as a mirror, freeform mirror, or waveguide). The performance of the PGU directly affects display brightness, resolution, contrast, and color reproduction, making it a key component determining the image quality of the HUD.

[0046] The radius of curvature refers to a geometric parameter that indicates the degree of curvature at a point on a curve or on a surface. It can be defined as the radius of the circle (or sphere) that is closest to the curve (or surface) at that point. The smaller the radius of curvature, the more pronounced the curvature, and vice versa. In the design of optical components (such as lenses and mirrors), the radius of curvature directly affects the path of light refraction or reflection.

[0047] Existing head-up display technologies mainly employ two optical path architectures: one is a single PGU combined with a dual optical path design for far and near views, which generates far and near view content in time or in different regions through the same image source; the other is a scheme of dual PGUs combined with a multiplexed plane mirror, which uses two independent image sources to process far and near view images respectively, and outputs the combined beam through a shared reflector.

[0048] However, although the former has a relatively compact structure, it is limited by a single optical path and it is difficult to independently adjust the vertical position of the near and far scenes, resulting in insufficient flexibility. Although the latter supports layered control of the image, it relies on a freeform surface mirror with a single surface shape, making it difficult to balance the imaging quality of near and far scenes under the same mirror width. This can easily lead to edge distortion or a decrease in sharpness. At the same time, the reuse of plane mirrors results in complex optical path folding and a large overall size, which is not conducive to integration in the space-constrained vehicle environment.

[0049] The display module provided in this application divides a freeform mirror into a near-field lens area and a far-field reflector area. Through optical path splitting and combining, and independently rotating reflective components, the vertical position of the near and far-field images is controlled separately, thereby optimizing image quality and improving the degree of freedom in image adjustment within a limited space. This overcomes the limitations of traditional PGU or dual PGU solutions, and solves the core problems of image quality degradation, bulky size, and insufficient adjustment freedom through regional optical design and dynamic adjustment mechanisms.

[0050] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0051] Figure 1 This is a schematic diagram of the structure of the display module provided in the embodiments of this application, such as... Figure 1 As shown, the display module includes a first light source assembly 110, a second light source assembly 120, a freeform mirror 130, and a reflection assembly 140. Wherein:

[0052] The first light source assembly 110 is used to emit a near-field light source to the freeform mirror 130.

[0053] The second light source assembly 120 is used to emit a distant light source to the freeform mirror 130;

[0054] The freeform mirror 130 includes a semi-transparent and semi-reflective coating region 131 and a mirror reflective surface region 132. The semi-transparent and semi-reflective coating region 131 is used to refract near-field light sources so that the near-field light sources are incident on the reflective component 140; the mirror reflective surface region 132 is used to reflect far-field light sources so that the far-field light sources are incident on the reflective component 140.

[0055] The reflective component 140 is used to adjust the reflection angle of the near light source and / or the far light source, and to project the near light source and the far light source after adjusting the reflection angle onto the projection surface 150 respectively.

[0056] Wherein, the first light source assembly 110 and the second light source assembly 120 can be PGUs. Wherein:

[0057] The first light source component 110 can refer to the optical module in the display module used to generate and emit near-field light sources, which can correspond to the image source for displaying near-field information (such as instrument data, operation prompts, etc.). This component can directionally project the generated light beam onto the semi-transparent and semi-reflective coating area of ​​the freeform mirror 130, serving as the starting point of the near-field image optical path and providing a basis for subsequent fusion or layered display with the distant image.

[0058] The second light source component 120 can refer to the optical module in the display module that is responsible for generating and emitting distant light sources. It can be used to present distant scenes or background information (such as navigation routes, environmental overlays, etc.). This component can directionally project the generated light beam onto the mirror reflection surface area 132 of the freeform mirror 130 so that it can enter the subsequent light path through reflection, thereby achieving spatial or visual distinction and integration with the near-field content.

[0059] The freeform mirror 130 can be an optical element with a complex aspherical geometry, and its surface may include a semi-transparent and semi-reflective coating region 131 and a mirror-reflecting surface region 132. Wherein:

[0060] The semi-transparent and semi-reflective coating region 131 allows some light to pass through (refract) while reflecting the rest. In this embodiment, the semi-transparent and semi-reflective coating region 131 allows the near-field optical path to "pass through" the freeform mirror 130 and continue to propagate, thereby achieving spatial separation and independent control from the far-field optical path.

[0061] The specular reflective surface area 132 can be a portion of the freeform mirror 130 without a semi-transparent, semi-reflective coating, or a portion specifically coated with a high-reflectivity metal / dielectric film, possessing near-total internal reflection optical performance. Its function is to efficiently reflect the distant light source from the second light source assembly 120, changing its propagation direction and guiding it to the reflective assembly 140. Through spatial partitioning with the semi-transparent, semi-reflective coating area 131, the specular reflective surface area 132 ensures that the distant light path enters the subsequent light path via reflection, avoiding crosstalk with the near-field beam, thereby reducing the space occupied and ensuring clear, layered display of the dual-view images.

[0062] The reflective component 140, located after the freeform mirror 130, receives two beams of light, one refracted (near-field light source) and the other reflected (far-field light source), and precisely controls their propagation directions (e.g., adjusting their respective reflection angles, optical axis alignment, or focusing states). Thus, this component can project the processed near-field and far-field light sources onto the projection surface 150 (such as a waveguide, screen, or human eye's field of view) along predetermined optical paths, achieving a clear and accurate superimposed display.

[0063] Therefore, by using a freeform surface mirror 130 in different regions to physically separate the near-field light source and the far-field light source, the volume expansion caused by the need for independent optical path superposition in traditional dual PGU solutions is avoided. The semi-transparent and semi-reflective coating, with its 50% transmission and 50% reflection characteristics, allows the two light paths to merge on the surface of the freeform surface mirror 130, thereby reducing redundant optical components. This adapts to the compact design requirements of the automotive front compartment and avoids increased assembly complexity and cost due to volume redundancy.

[0064] Optionally, the radius of curvature of the freeform mirror 130 shall satisfy at least one of the following conditions:

[0065] The radius of curvature of the semi-transparent and semi-reflective coating region 131 is 500mm-3500mm;

[0066] The radius of curvature of the mirror-reflecting surface region 132 is 2000mm-3000mm.

[0067] For example, the radius of curvature of the semi-transparent and semi-reflective coating region 131 can be 500mm, 800mm, 1200mm, 1800mm, 2500mm, 3000mm, or 3500mm. Among them, 500mm is suitable for near-field optical paths requiring strong convergence capabilities, shortening the overall length; 800mm balances compactness and image quality; 1200mm provides a smoother refractive surface, helping to reduce higher-order aberrations and is suitable for high-resolution near-field displays; 1800mm is a compromise, balancing optical path folding efficiency and field of view uniformity; 2500mm, with curvature close to that of distant areas, facilitates coaxial optimization of dual optical paths, improving the naturalness of fusion; 3000mm, with a surface close to a plane, is suitable for applications sensitive to wavefront distortion, emphasizing high-fidelity imaging; and 3500mm, with a surface extremely close to a plane, introduces almost no additional optical path difference, suitable for applications highly sensitive to wavefront distortion, emphasizing high-fidelity, low-aberration near-field imaging.

[0068] The radius of curvature of the mirror reflecting area 132 can be 2000mm, 2250mm, 2500mm, 2750mm, or 3000mm. At 2000mm, the mirror exhibits good focusing performance while maintaining a relatively large field of view. At 2250mm, a slightly gentler curve is provided, helping to further reduce aberrations and improve the overall image sharpness and realism. At 2500mm, the intermediate radius of curvature matches the natural viewing habits of the human eye well, providing users with a comfortable and natural visual experience. At 2750mm, the near-planar design minimizes changes in beam direction, helping to maintain the integrity and consistency of the original optical path. At 3000mm, any deformation or distortion caused by the mirror shape can be reduced.

[0069] In this embodiment of the application, when the difference in the radius of curvature between the semi-transparent and semi-reflective coating area 131 and the mirror reflective surface area 132 is less than or equal to 500 mm, the semi-transparent and semi-reflective coating area 131 and the mirror reflective surface area 132 are integrally formed.

[0070] When the difference in the radius of curvature between the semi-transparent and semi-reflective coating area 131 and the mirror reflective surface area 132 is greater than 500 mm, the semi-transparent and semi-reflective coating area 131 and the mirror reflective surface area 132 are set separately.

[0071] Among them, when the radius of curvature difference between the semi-transparent and semi-reflective coating region 131 and the mirror reflection surface region 132 is... At 500mm, the surface morphology of the semi-transparent and semi-reflective coating region 131 is similar to that of the mirror-reflective surface region 132, allowing for integral molding using the same substrate. This ensures optical surface continuity, reduces assembly errors, simplifies the process, and lowers costs. However, when the radius of curvature differs... At 500mm, the surface differences between the two regions are significant. If they are forcibly molded as a single unit, the processing difficulty will increase dramatically, the surface accuracy will decrease, or stress deformation will occur. Therefore, a separate setting (such as splicing two independent optical elements or installing them separately) can be adopted to optimize the surface accuracy of each individual, ensuring the imaging quality of the near-field light source and the far-field light source, thereby improving reliability and yield.

[0072] In some embodiments, the semi-transparent and semi-reflective coating region 131 can also detect the ambient light intensity through an ambient light sensor and dynamically adjust the ratio of transmittance to reflectance according to the ambient light intensity.

[0073] Among them, the ambient light sensor refers to a sensor used to detect the intensity of ambient light, which is used to dynamically adjust the parameters of the optical coating. For example, in a strong backlight scene, the ambient light sensor detects a high light intensity signal, and the system reduces the reflectivity of the semi-transparent and semi-reflective coating to reduce glare interference; in a night driving scene, the ambient light sensor detects a low light intensity signal, and the system increases the transmittance of the semi-transparent and semi-reflective coating to enhance image brightness.

[0074] Optionally, the reflective assembly 140 includes a first reflector 141 and a second reflector 142, wherein the first reflector 141 and the second reflector 142 are respectively connected to the adjustment mechanism, wherein...

[0075] The first reflector 141 is used to reflect the distant light source to the projection surface 150 at a first preset angle.

[0076] The second reflector 142 is used to reflect the near-field light source to the projection surface 150 at a second preset angle.

[0077] The first reflector 141 reflects distant light sources reflected by the freeform mirror 130 at a specific first preset angle, accurately projecting them onto the corresponding area of ​​the projection surface 150. The second reflector 142 reflects near light sources passing through the semi-transparent and semi-reflective area of ​​the freeform mirror 130 at another independent second preset angle, also guiding them to the projection surface 150. Thus, by setting two reflection angles respectively, spatial alignment, field-of-view overlay, or depth layering of near and far images on the projection surface 150 can be achieved, thereby supporting multi-depth-of-field fusion display and improving the visual experience and information readability of augmented reality or head-up displays.

[0078] In this embodiment, the adjustment mechanism is used to obtain the optical path offset and adjust the tilt angle of the first reflector 141 and / or the tilt angle of the second reflector 142 according to the optical path offset; the optical path offset represents the offset of the reflection assembly 140 reflecting the near-field light source and / or the far-field light source to the projection surface 150.

[0079] The adjustment mechanism can refer to an optical alignment device. In some embodiments, it may include a position detection unit (such as a photoelectric position sensor or image sensor), a processing module (for calculating deviation), and a fine-tuning execution unit (such as a piezoelectric actuator, micromotor, or MEMS micromirror driver). This adjustment mechanism can sense the actual landing point of the light beam on the projection surface 150 in real time and precisely adjust the pitch or deflection angle of the first reflector 141 and / or the second reflector 142 through feedback control, thereby dynamically correcting the optical path and ensuring that the near-field and far-field images are stably and accurately projected to the preset position.

[0080] For example, during operation, the image sensor in the adjustment mechanism can capture the actual light spot positions of the near and far light sources on the projection surface 150 in real time and transmit the data to the processing module. The processing module compares the measured coordinates with the preset ideal imaging coordinates and calculates the optical path offset (e.g., the near light spot is offset to the right by 0.2mm and the far light spot is offset upward by 0.15mm). Subsequently, the control algorithm generates corresponding correction commands to drive the piezoelectric actuator to finely adjust the pitch angle of the first reflector 141 to correct the far offset, while controlling the micro motor to adjust the deflection angle of the second reflector 142 to compensate for the near offset. After several closed-loop feedbacks, both beams of light are precisely guided to the target position, realizing a stable and high-precision superimposed display of dual-depth images.

[0081] Optical path offset refers to the deviation of the imaging center or feature point of the actual light beam from its ideal design position on the horizontal, vertical, or two-dimensional plane when it is projected onto the projection surface 150 via the reflector 140. This offset can be caused by factors such as manufacturing tolerances, assembly errors, temperature changes, or mechanical shocks. It is an important indicator for measuring the imaging accuracy and stability of the system, and also a direct basis for the adjustment mechanism to perform angle compensation.

[0082] For example, the actual imaging point of the near-field light source on the projection surface 150 may be offset to the right by 0.3 mm and upward by 0.1 mm relative to the design center position; or the center of the light spot of the far-field light source may deviate from the ideal field of view coordinates by 0.25 mm, resulting in a horizontal misalignment; or after temperature changes cause slight deformation of the frame, a relative displacement of 0.4 mm may occur in the overlapping area of ​​the two optical paths on the projection surface 150. Therefore, the tilt angle of the first reflector 141 and / or the tilt angle of the second reflector 142 can be adjusted by the optical path offset.

[0083] In some embodiments, vehicle attitude data can also be acquired by a gyroscope sensor, and the rotation angle of the reflector 140 can be dynamically adjusted based on the vehicle attitude data.

[0084] A gyroscope sensor can refer to a sensor used to detect vehicle attitude (such as turning or sloping) and dynamically adjust the angle of a reflector. After obtaining vehicle attitude data from the gyroscope sensor, the rotation angle can be dynamically adjusted based on the detection results. For example, the gyroscope sensor can collect vehicle attitude information such as angular velocity, roll, pitch, and yaw in real time, and combine it with the vehicle speed signal to estimate the current turning radius and vehicle dynamics. Subsequently, the onboard processing unit (such as an ADAS domain controller) converts the vehicle's turning state into the driver's expected line-of-sight offset angle (such as a natural 15° shift to the left and forward when turning left). Then, this target angle is sent to the reflector drive module (such as a voice coil motor or MEMS micromirror with integrated PID control), which drives the independently rotating reflector to tilt precisely around a specific axis, causing the projected light path to deflect synchronously, ensuring that the virtual information such as navigation arrows and lane lines in the head-up display system are always stably "fitted" to the corresponding positions on the real road.

[0085] The ADAS domain controller receives yaw rate signals from the gyroscope and vehicle speed signals from the wheel speed sensors in real time via the CAN bus. It first calculates the current turning radius. Then, based on a pre-calibrated gaze mapping strategy (e.g., setting the driver's gaze point to be 80 meters ahead of the curve), it quickly calculates the expected horizontal gaze offset angle using trigonometric relationships. After filtering and smoothing, this angle value is sent as a target command to the reflector drive circuit in the head-up display system. The latter drives the independently rotating reflector to deflect around the vertical axis by a corresponding angle, so that the virtual image position of the projected image (such as a navigation arrow) on the windshield automatically moves to the inside of the curve, always aligned with the driver's natural line of sight.

[0086] In this embodiment of the application, the freeform mirror 130 and the reflection component 140 satisfy at least one of the following conditions:

[0087] The length ratio of the semi-transparent and semi-reflective coating region 131 to the first reflective element 141 is 1.6 to 1.8;

[0088] The width ratio of the semi-transparent and semi-reflective coating region 131 to the width of the first reflective element 141 is 1.5 to 1.7;

[0089] The ratio of the radius of curvature of the semi-transparent and semi-reflective coating region 131 to that of the first reflective element 141 is 0.75 to 0.85;

[0090] The length ratio of the mirror-reflecting surface area 132 to the second reflector 142 is 1.6 to 1.8;

[0091] The width ratio of the mirror reflective surface area 132 to the width of the second reflector 142 is 1.1 to 1.2;

[0092] The ratio of the radius of curvature of the mirror reflective surface region 132 to that of the second reflector 142 is 1.25 to 1.35.

[0093] For example, when the length of the semi-transparent and semi-reflective coating region 131 is 210 mm, the length of the first reflective element 141 can be between 336 mm and 378 mm.

[0094] When the width of the semi-transparent and semi-reflective coating region 131 is 70 mm, the width of the first reflective element 141 can be between 105 mm and 119 mm.

[0095] When the radius of curvature of the semi-transparent and semi-reflective coating region 131 is 2810 mm, the radius of curvature of the first reflector 141 can be between 2108 mm and 2389 mm.

[0096] When the length of the mirror reflective surface area 132 is 210mm, the length of the second reflector 142 can be between 336mm and 378mm.

[0097] When the width of the mirror reflective surface area 132 is 80mm, the width of the second reflector 142 can be between 88mm and 96mm.

[0098] When the radius of curvature of the mirror reflective surface region 132 is 2330mm, the radius of curvature of the second reflector 142 can be between 2913mm and 3146mm.

[0099] In this embodiment, an infrared cutoff coating is provided on the reflective surface of the first reflector 141 and / or the reflective surface of the second reflector 142.

[0100] The semi-transparent and semi-reflective coating region 131 includes at least one of a high reflectivity film, an infrared cutoff film, and an anti-reflection film.

[0101] High-reflectivity films can refer to optical coatings designed using multilayer dielectric films or metal-dielectric composite structures, used to achieve a high proportion of reflection of incident light within a specific wavelength range (such as visible light 400-700nm). In the semi-transparent and semi-reflective coating region 131, the film can enhance the reflection efficiency of partially polarized or specific color light, while taking into account transmission requirements, so as to optimize the energy utilization and contrast of near-field light sources.

[0102] An infrared cutoff film is an optical thin film that selectively filters out infrared light (typically above 700nm) to prevent infrared radiation from PGU light sources or the environment from entering the human eye or imaging system. This film avoids the impact of infrared thermal effects on display clarity, reduces visual fatigue, and prevents infrared light from interfering with subsequent optical sensors (such as eye-tracking cameras), thus improving system security and image purity.

[0103] Anti-reflective coatings refer to anti-reflective coatings made of single or multiple layers of low-refractive-index materials, used to reduce Fresnel reflection loss caused by refraction on the surface of a freeform mirror 130. In the semi-transparent and semi-reflective region, anti-reflective coatings can improve the transmission efficiency of near-field light sources, suppress ghosting and stray light, thereby enhancing image brightness, contrast, and overall visual clarity.

[0104] Optionally, the first light source assembly 110 is disposed above the freeform mirror 130, and the second light source assembly 120 and the reflection assembly 140 are disposed below the freeform mirror 130, with the reflection assembly 140 disposed closer to the projection surface 150 relative to the second light source assembly 120.

[0105] The first reflector 141 and the second reflector 142 in the reflective assembly 140 are stacked one on top of the other.

[0106] The first light source assembly 110 is located above the freeform mirror 130 and is used to emit a near-field light source downwards to the mirror surface. The second light source assembly 120 and the reflection assembly 140 are arranged below the freeform mirror 130. The reflection assembly 140 is closer to the projection surface 150 so as to receive and guide the light beam processed by the freeform mirror 130 in a timely manner. The first reflector 141 and the second reflector 142 inside the reflection assembly 140 adopt an upper and lower stacked structure, that is, one is located above or below the other, sharing a compact vertical space. This not only realizes independent control of the dual optical paths, but also effectively saves the horizontal installation area, which is conducive to the miniaturization of the whole machine and the efficient integration of the optical path.

[0107] In this embodiment of the application, the first light source assembly 110 includes a first light source 111 and a specular reflector 112, and a polarization selection film is provided on the reflective surface of the specular reflector 112.

[0108] The first light source 111 is used to emit a near-field light source to the mirror reflector 112;

[0109] The mirror reflector 112 is used to reflect the mirror reflector 112 onto the freeform mirror 130.

[0110] The first light source assembly 110 can be composed of a first light source element 111 and a specular reflector element 112. The first light source element 111 emits a near-field light source and projects it onto the specular reflector element 112. The specular reflector element 112 has a polarization selective film on its reflective surface, which can selectively reflect light with a specific polarization direction according to the polarization state of the light, while suppressing other polarization components, thereby improving the light efficiency and image contrast. The near-field light source reflected by the specular reflector element 112 is guided to the freeform mirror 130 and enters the subsequent optical path, realizing efficient and low stray light transmission of near-field information.

[0111] The display module provided in this application embodiment employs a freeform surface mirror with a segmented design. The near-field light path is refracted through a semi-transparent, semi-reflective coating area, while the far-field light path is reflected through a mirror reflection surface area. This separation of the two paths effectively avoids the distortion and aberration problems that easily occur in traditional single-surface mirrors under a large field of view, resulting in a clearer image and more uniform brightness. The overall optical path adopts a folded layout, using a freeform surface mirror in conjunction with a mirror reflector, reducing the number of required reflectors. Furthermore, the first and second reflectors are independently set, eliminating the need for additional plane mirrors, resulting in a more compact structure and easier placement within the limited space of a car's front compartment. In addition, the first and second reflectors can be adjusted at their tilt angles independently, allowing the near and far-field images to move independently up and down to adapt to different driver postures and eye levels. Adjustments are independent and do not interfere with each other, making it more flexible to use. The system also integrates an infrared cutoff coating on the surfaces of the first and second reflectors to filter out infrared stray light from the environment, and adds a polarization selection film to the mirror reflection surface to further improve image contrast and reduce glare interference, resulting in a more stable and clearer overall display effect.

[0112] Figure 2 This is a schematic diagram of the optical path of the display module provided in this application, as shown below. Figure 2 As shown, the optical path of the display module includes: a near-view PGU210, a far-view PGU220, a plane mirror 230, a curved mirror 240, a first freeform surface mirror 250, a second freeform surface mirror 260, and a windshield 270.

[0113] Among them, the near-field PGU210 can be the first light source component in the first light source assembly; the plane mirror 230 can be a mirror reflector with a mirror reflective surface, and can use polarization selective film or coating; the far-field PGU220 can be the second light source assembly.

[0114] The PGU210 for close-up projection and the PGU220 for long-range projection are not limited to any projection format and can be either TFT-LCD (Thin-Film Transistor Liquid Crystal Display) or LCoS (Liquid Crystal on Silicon).

[0115] The curved mirror 240 can be a freeform mirror with a semi-transparent and semi-reflective coating. It can be divided into two areas. One area is area one 241, which is the semi-transparent and semi-reflective coating area, i.e. the freeform lens part for near-view, with a curvature radius set at 500mm-3500mm. The other area can be area two 242, which is the mirror reflection surface area, i.e. the freeform mirror reflection part for far-view, with a curvature radius set at 2000mm-3000mm.

[0116] In some embodiments, region 241 and region 242 of the curved mirror 240 can be separated or connected together. That is, when the difference in the radius of curvature between region 241 and region 242 is within 500mm, region 241 and region 242 can be connected.

[0117] The surfaces of the first freeform surface reflector 250 and the second freeform surface reflector 260 are mirror reflective surfaces and may have an infrared cutoff coating.

[0118] The first freeform surface mirror 250 can correspond to region two 242, and the second freeform surface mirror 260 can correspond to region one 241.

[0119] The first freeform surface reflector 250 and the second freeform surface reflector 260 can rotate. Their rotation function can be achieved by setting a circular axis on the short side, and the form is not limited.

[0120] The length, width, and radius of curvature of the first freeform surface mirror 250 and the second freeform surface mirror 260 can be set based on the length, width, and radius of curvature of region two 242 and region one 241. For example, when the length, width, and radius of curvature of region two 242 and region one 241 are respectively , When the diameters are 2810mm and 2330mm, the corresponding lengths, widths, and radii of curvature of the first freeform surface mirror 250 and the second freeform surface mirror 260 are respectively... , And 2230mm, 3050mm.

[0121] In this embodiment, the light from optical path 1 is provided by the near-field PGU 210, incident on the plane mirror 230 for specular reflection, and then incident on region 241. It is refracted in the curved mirror 240 and incident on the second freeform mirror 260, finally reflected onto the windshield 270 and observed by the human eye.

[0122] The light from optical path 2 is provided by the distant PGU220, incident on region 242 and reflected. It then incident on the first freeform surface mirror 250, and finally reflected on the windshield 270 and observed by the human eye.

[0123] The display module provided in this application embodiment can not only effectively improve the imaging quality within a limited space, or achieve a smaller size while maintaining the same performance, but also flexibly adjust the vertical position of the image in the near and far-field optical paths by independently controlling the angles of the first and second freeform surface reflectors, thereby improving the freedom of image adjustment.

[0124] This application provides a head-up display system, including a display module.

[0125] In the embodiments of this application, the head-up display system can be widely used in the fields of intelligent vehicles, high-end passenger vehicles and commercial vehicles, projecting key information such as vehicle speed, navigation guidance, and driving assistance information onto the driver's forward field of vision, reducing eye deviation and improving driving safety; at the same time, with the development of augmented reality (AR) technology, the head-up display system can also integrate virtual information with real roads for functions such as lane-level navigation, collision warning, and pedestrian recognition.

[0126] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A display module, characterized in that, It includes a first light source assembly, a second light source assembly, a freeform mirror, and a reflection assembly; wherein: The first light source assembly is used to emit a close-up light source to the freeform mirror; The second light source assembly is used to emit a distant light source to the freeform mirror; The freeform mirror includes a semi-transparent and semi-reflective coating area and a mirror-reflective surface area. The semi-transparent and semi-reflective coating area is used to refract the near-field light source, so that the near-field light source is incident on the reflective component. The mirror-reflective surface area is used to reflect the far-field light source, so that the far-field light source is incident on the reflective component. The reflective component is used to adjust the reflection angle of the near-field light source and / or the far-field light source, and to project the near-field light source and the far-field light source after adjusting the reflection angle onto the projection surface, respectively.

2. The display module according to claim 1, characterized in that, The radius of curvature of the freeform mirror must satisfy at least one of the following conditions: The radius of curvature of the semi-transparent and semi-reflective coating region is 500mm-3500mm; The radius of curvature of the mirror-reflecting surface region is 2000mm-3000mm.

3. The display module according to claim 2, characterized in that, When the difference in the radius of curvature between the semi-transparent and semi-reflective coating area and the mirror reflective surface area is less than or equal to 500 mm, the semi-transparent and semi-reflective coating area and the mirror reflective surface area are integrally formed. When the difference in the radius of curvature between the semi-transparent and semi-reflective coating area and the mirror reflective surface area is greater than 500 mm, the semi-transparent and semi-reflective coating area and the mirror reflective surface area are separated.

4. The display module according to claim 1, characterized in that, The reflective assembly includes a first reflector and a second reflector, which are respectively connected to an adjustment mechanism. The first reflector is used to reflect the distant light source onto the projection surface at a first preset angle; The second reflector is used to reflect the near-field light source onto the projection surface at a second preset angle.

5. The display module according to claim 4, characterized in that, The adjustment mechanism is used to acquire the optical path offset and adjust the tilt angle of the first reflector and / or the tilt angle of the second reflector according to the optical path offset; the optical path offset represents the offset by which the reflective assembly reflects the near-field light source and / or the far-field light source onto the projection surface.

6. The display module according to claim 4, characterized in that, The freeform mirror and the reflective component satisfy at least one of the following conditions: The length ratio of the semi-transparent and semi-reflective coating area to the length of the first reflective element is 1.6 to 1.8; The width ratio of the semi-transparent and semi-reflective coating area to the width of the first reflective element is 1.5 to 1.7; The ratio of the radius of curvature of the semi-transparent and semi-reflective coating region to that of the first reflective element is 0.75 to 0.85; The length ratio of the mirror-reflecting surface area to the second reflector is 1.6 to 1.8; The width ratio of the mirror-reflecting surface area to the width of the second reflector is 1.1 to 1.2; The ratio of the radius of curvature of the mirror-reflecting surface area to that of the second reflector is 1.25 to 1.

35.

7. The display module according to claim 4, characterized in that, An infrared cutoff coating is provided on the reflective surface of the first reflector and / or the reflective surface of the second reflector. The semi-transparent and semi-reflective coating region includes at least one of a high reflectivity film, an infrared cutoff film, and an anti-reflection film.

8. The display module according to any one of claims 1 to 7, characterized in that, The first light source assembly is disposed above the freeform mirror, the second light source assembly and the reflection assembly are disposed below the freeform mirror, and the reflection assembly is disposed closer to the projection surface than the second light source assembly; The first reflector and the second reflector in the reflective assembly are stacked one on top of the other.

9. The display module according to claim 8, characterized in that, The first light source assembly includes a first light source element and a specular reflector element, wherein a polarization selection film is provided on the reflective surface of the specular reflector element; The first light source is used to emit a near-field light source to the mirror reflector; The mirror reflector is used to reflect the mirror reflector onto the freeform mirror.

10. A head-up display system, characterized in that, The display module includes any one of claims 1 to 9.

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