Panoramic head-up display device based on double LBS projection

Abstract

The invention discloses a panoramic head-up display device based on double-LBS projection, and relates to the technical field of head-up display, the panoramic head-up display device comprises a double-LBS projection unit, a projection optical system, a glass projection surface and an image processing and control unit, the double-LBS projection unit is used for emitting two beams of three-color laser and performing two-dimensional deflection and modulation on the three-color laser; the glass projection surface comprises a glass substrate and an optical anti-reflection film located on the glass substrate, the scheme that the two LBS projection modules are spliced is adopted, the bottleneck that the field angle of a single LBS module is limited is fundamentally broken through, display of a panoramic large picture is successfully achieved, and meanwhile the effect that the field angle of the single LBS module is limited is achieved. The image processing and control unit is used for carrying out geometric correction and pixel-level brightness and chroma fusion on the overlapped region, so that the difficult-to-avoid splicing mark problems such as uneven brightness, chromatic aberration and geometric dislocation in the traditional multi-module splicing are effectively eliminated, and finally, a visual integrated, coherent and seamless high-quality virtual image is presented; and the impression immersion degree and the information display integrity are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of head-up display technology, and more specifically to a panoramic head-up display device based on dual LBS projection. Background Technology

[0002] Head-up displays (HUDs) have become an important feature for enhancing the driving experience and safety of modern cars. Traditional HUD devices mostly use projection methods based on thin-film transistor liquid crystal displays (TFT-LCDs) or digital light processing (DLP) technologies, combined with complex freeform surface optical systems, which have problems such as large size, high cost, and insufficient contrast under strong light.

[0003] Laser Beam Scanning (LBS) is an emerging display technology that directly renders images by controlling micro-mirrors to deflect a laser beam. It boasts inherent advantages such as a wide color gamut, high brightness, excellent contrast, and no need for focusing. However, applying LBS to HUDs, especially to achieve large field-of-view and high-resolution displays, presents several technical challenges: the field of view and resolution of a single LBS module are limited, making it difficult to meet the demands of large-screen displays in vehicles; if multiple LBS modules are used for image stitching, inconsistencies in brightness and color, as well as geometric misalignments, will create noticeable "stitching marks" at the stitching points, severely compromising visual integrity and overall appearance; and the projection surface (such as the windshield) will experience severe reflection and glare under strong light, reducing the readability of the displayed content.

[0004] Therefore, there is a lack of compact HUD devices in the current technology that can fully leverage the advantages of LBS technology while solving the problems of seamless large-screen splicing and ambient light interference. Summary of the Invention

[0005] The purpose of this invention is to provide a panoramic head-up display device based on dual LBS projection, which solves the technical problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the present invention specifically provides the following technical solution:

[0007] A panoramic head-up display device based on dual LBS projection includes a dual LBS projection unit, a projection optical system, a glass projection surface, and an image processing and control unit. The dual LBS projection unit is used to emit two beams of three-color lasers and to perform two-dimensional deflection and modulation on the three-color lasers. The projection optical system has two beams and is used to collimate, expand, and correct aberrations of the corresponding three-color laser beams. The glass projection surface receives the beams of three-color lasers to form sub-images with overlapping areas. The image processing and control unit segments, corrects, and fuses the received panoramic video signal to generate two synchronous sub-image signals. The two sub-image signals drive the dual LBS projection unit to project the three-color laser beams. The glass projection surface includes a glass substrate and an optical anti-reflection film located on the glass substrate.

[0008] As a preferred embodiment of the present invention, the dual LBS projection unit includes two identical LBS projection modules capable of projecting sub-images. Each LBS projection module includes an RGB laser light source group, a miniature scanning mirror, and a control and drive circuit. The RGB laser light source group is used to emit three-color lasers, the miniature scanning mirror is used to deflect the beam of the three-color lasers, and the control and drive circuit is used to receive video signals and synchronization signals from the image processing and control unit, and synchronously drive the miniature scanning mirror to deflect along a predetermined trajectory. The LBS projection modules and the projection optics system together constitute an LBS projection system.

[0009] As a preferred embodiment of the present invention, the two LBS projection modules are placed symmetrically, and the optical axes of the two LBS projection modules intersect in space.

[0010] In a preferred embodiment of the present invention, the projection optical system is configured correspondingly to the LBS projection module. The projection optical system includes a collimating and beam-expanding lens group and an objective lens group. The collimating and beam-expanding lens group is used to collimate and expand the three-color laser beam emitted by the LBS projection module to form a parallel beam. The objective lens group is used to guide the three-color laser beam passing through the collimating and beam-expanding lens group to a set projection area and correct aberrations. The sub-images projected by the two LBS projection modules have a predetermined overlapping area on the glass projection surface through the guidance of the projection optical system.

[0011] As a preferred embodiment of the present invention, the image processing and control unit includes a video signal splitter, a stitching area image processing module, and a synchronization controller. The video signal splitter receives the panoramic video signal and splits the input panoramic video signal into two sub-screen signals in real time. The stitching area image processing module is used to perform geometric distortion correction on the sub-screens and eliminate the difference in brightness and color when the two LBS projection modules project.

[0012] As a preferred embodiment of the present invention, the splicing area image processing module includes a geometric correction module and a fusion module. The geometric correction module is used to correct the geometric distortion of the two sub-images, and the fusion module is used to eliminate the difference in brightness and color when the two LBS projection modules are projected.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] (1) The present invention adopts a splicing scheme of two LBS projection modules, which fundamentally breaks through the bottleneck of the limited field of view of a single LBS module and successfully realizes the display of a panoramic large screen. At the same time, through the image processing and control unit, geometric correction and pixel-level brightness and color fusion of the overlapping area are performed, effectively eliminating the "splitting marks" problems such as uneven brightness, color difference and geometric misalignment that are difficult to avoid in traditional multi-module splicing. Finally, a high-quality virtual image with visual unity and seamless continuity is presented, which greatly improves the immersive viewing experience and the integrity of information display.

[0015] (2) By using special glass coated with multiple layers of optical anti-reflection film as the projection surface, the present invention greatly suppresses the reflection and glare of ambient light (especially strong sunlight) on the glass projection surface, improves the contrast of the displayed virtual image, and ensures that key driving information (such as vehicle speed and navigation arrows) can be clearly and conspicuously presented to the driver under various lighting conditions such as day and dusk, reducing information omissions or misjudgments caused by glare interference and enhancing driving safety.

[0016] (3) The present invention adopts an RGB laser light source group, which inherits the inherent advantages of laser display in terms of wide color gamut, high brightness and excellent contrast. The displayed image is more vivid and realistic, and can maintain excellent visual clarity under various ambient light backgrounds. Since LBS technology uses collimated scanning laser beams for projection, after passing through the optical system, it forms parallel light or quasi-parallel light projection, so that the generated virtual image has a deep focal plane. This allows the driver to see clearly without adjusting the focal length of the eyeball when viewing information at different eye positions or at different distances, reducing visual fatigue and improving safety and comfort. Secondly, the LBS projection module itself has a small structure. Combined with a relatively simple collimation and beam combining optical design, it avoids the complex freeform optical elements and huge optical path space in traditional HUDs, which greatly reduces the size and weight of the entire device and makes it easier to arrange and integrate in the limited space of the vehicle. Attached Figure Description

[0017] To more clearly illustrate the embodiments of the present invention or the technical solutions in 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 merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0018] Figure 1 This invention provides a schematic diagram of the overall structure of a panoramic head-up display device based on dual LBS projection.

[0019] Figure 2 This invention provides a structural schematic diagram of the LBS projection system and the glass projection surface;

[0020] Figure 3 A schematic diagram of the structure of the image processing and control unit is provided for this invention.

[0021] The labels in the diagram represent the following:

[0022] 1. LBS projection system; 2. Image processing and control unit; 3. Glass projection surface; 11. RGB laser light source group; 12. Collimating and beam expanding lens group; 13. Miniature scanning mirror; 14. Objective lens group; 31. Glass substrate; 32. Optical anti-reflection coating; 4. Lateral overlapping area. Detailed Implementation

[0023] 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.

[0024] The concepts involved in this application will first be described with reference to the accompanying drawings. It should be noted that the following descriptions of various concepts are only for the purpose of making the content of this application easier to understand and do not constitute a limitation on the scope of protection of this application; furthermore, the embodiments and features in the embodiments of this application can be combined with each other unless otherwise specified. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] like Figures 1 to 3As shown, the present invention provides a panoramic head-up display device based on dual LBS projection, including a dual LBS projection unit, a projection optical system, a glass projection surface 3, and an image processing and control unit 2. The dual LBS projection unit is used to emit two beams of three-color lasers and to perform two-dimensional deflection and modulation of the three-color lasers. The projection optical system has two beams and is used to collimate, expand, and correct aberrations of the corresponding three-color laser beams. The glass projection surface 3 receives the beams of three-color lasers to form sub-images with overlapping areas. The image processing and control unit 2 divides, corrects, and fuses the received panoramic video signal and generates two synchronous sub-image signals. The two sub-image signals drive the dual LBS projection unit to project the three-color laser beams. The glass projection surface 3 includes a glass substrate 31 and an optical anti-reflection film 32 located on the glass substrate 31.

[0026] The image processing and control unit 2 segments, corrects, and fuses the panoramic image to generate two synchronous sub-image signals, driving the dual LBS projection units. The LBS projection module emits two three-color laser beams, which are collimated, expanded, and aberration corrected by their respective projection optics systems before being projected onto the glass projection surface 3 with an optical anti-reflection film 32, forming two high-quality sub-images with precisely overlapping areas. The image processing and control unit 2 corrects the sub-images by correcting their geometric distortion, ensuring image alignment. The fusion eliminates the differences in brightness and color at the overlapping areas, ultimately synthesizing a panoramic virtual image with a large field of view, high brightness, and high contrast in front of the driver's field of vision. The entire device fully utilizes the advantages of LBS technology, such as high brightness, wide color gamut, and no need for focusing, and combined with dual-projection splicing, effectively solves the problems of limited field of view of a single LBS and ambient light interference.

[0027] The glass substrate 31 provides a flat and robust projection interface. It uses glass with high optical flatness as the substrate. The optical anti-reflection film 32 coated on the glass substrate 31 has extremely high transmittance and extremely low reflectance for the RGB band and nearby bands of laser emitted by the LBS light source. It significantly suppresses the specular reflection and diffuse reflection of ambient light (such as sunlight and oncoming car headlights) on the glass projection surface 3, thereby greatly reducing background glare and improving the contrast and readability of the displayed content under strong light. It overcomes the visibility problem of traditional projection surfaces in bright environments. The optical anti-reflection film 32 is coated on the glass substrate 31 in multiple layers.

[0028] The dual LBS projection unit includes two identical LBS projection modules capable of projecting sub-images. Each LBS projection module includes an RGB laser light source group 11, a miniature scanning mirror 13, and a control and drive circuit. The RGB laser light source group 11 is used to emit three-color lasers, and the miniature scanning mirror 13 is used to deflect the beam of the three-color lasers. The control and drive circuit is used to receive video signals and synchronization signals from the image processing and control unit 2, and synchronously drive the miniature scanning mirror 13 to deflect along a predetermined trajectory. The LBS projection modules and the projection optics system together constitute the LBS projection system 1.

[0029] Two LBS projection modules are placed symmetrically, and the optical axes of the two LBS projection modules intersect in space.

[0030] The dual LBS projection unit is the core of image generation. It consists of two identical LBS projection modules arranged symmetrically. The optical axes of the two LBS projection modules intersect at a certain angle in space, ultimately projecting the two sub-images onto the same glass projection surface 3 to form a stitched panoramic virtual image for the driver to observe. The RGB laser light source group 11 uses red (R), green (G), and blue (B) three-primary-color semiconductor lasers. The laser light source has the inherent advantages of wide color gamut, high brightness, and good monochromaticity, providing an excellent foundation for color saturation and contrast in the final image.

[0031] The miniature scanning mirror 13 acts as a beam deflection actuator, enabling high-speed and high-precision two-dimensional deflection under the control of a drive signal. The control and drive circuit receives video and synchronization signals from the image processing and control unit 2, precisely modulates the light intensity of each color laser (achieving grayscale control), and synchronously drives the miniature scanning mirror 13 to deflect along a predetermined trajectory.

[0032] Specifically, the miniature scanning mirror 13 is controlled by a control and drive circuit and adopts a two-dimensional electromagnetic drive MEMS micromirror, which can perform high-speed scanning on two axes in resonant or non-resonant modes to form the deflection of the laser beam.

[0033] The control and drive circuit is existing technology. It receives video signals and synchronization signals from the image processing and control unit 2. The control and drive circuit analyzes the video signals and generates corresponding laser modulation signals and micromirror deflection drive signals to achieve point-by-point scanning imaging. The physical installation positions and light output directions of the two LBS projection modules are precisely adjusted so that the images they project have an adjustable-width horizontal overlap area 4 on the glass projection surface 3.

[0034] Two LBS projection modules are placed symmetrically at a preset angle, so that their emitted light axes intersect in space. During operation, the image processing and control unit 2 performs strict timing synchronization and pixel-level trigger control to ensure that the start time, line frequency, and frame frequency of the two LBS projection modules are completely consistent, laying the foundation for subsequent image geometric stitching.

[0035] Furthermore, the LBS projection module itself has a compact structure, combined with a relatively simple collimation and beam combining optical design, avoiding the complex freeform optical elements and huge optical path space in traditional HUDs, which greatly reduces the size and weight of the entire device, making it easier to arrange and integrate in the limited space of a vehicle.

[0036] The projection optics system is configured to correspond with the LBS projection module. The projection optics system includes a collimating and beam-expanding lens group 12 and an objective lens group 14. The collimating and beam-expanding lens group 12 is used to collimate and expand the three-color laser beam emitted by the LBS projection module to form a parallel beam. The objective lens group 14 is used to guide the three-color laser beam that has passed through the collimating and beam-expanding lens group 12 to the set projection area and correct aberrations. The sub-images projected by the two LBS projection modules have a predetermined overlap area on the glass projection surface 3 through the guidance of the projection optics system.

[0037] Each LBS projection module corresponds to a projection optics system for beam collimation, beam expansion, and aberration correction. This projection optics system includes a collimating and beam-expanding lens group 12 and an objective lens group 14. The collimating and beam-expanding lens group 12 collimates and expands the three-color laser beam emitted from the RGB laser light source group 11, forming a parallel beam, ensuring that the displayed content remains clear on the windshield (projection surface) at different distances or when the driver's eyes move. The objective lens group 14 guides the collimated three-color laser beam to the designated projection area (i.e., the glass projection surface 3) while simultaneously correcting aberrations, ensuring that the two sub-images projected by the two LBS projection modules have a predetermined overlap area on the glass projection surface 3.

[0038] The image processing and control unit 2 includes a video signal splitter, a stitching area image processing module, and a synchronization controller. The video signal splitter receives the panoramic video signal and splits the input panoramic video signal into two sub-screen signals in real time. The stitching area image processing module is used to correct the geometric distortion of the sub-screens and eliminate the difference in brightness and color when the two LBS projection modules are projected.

[0039] The image processing module for the splicing area includes a geometric correction module and a fusion module. The geometric correction module is used to correct the geometric distortion of the two sub-images, and the fusion module is used to eliminate the differences in brightness and color when the two LBS projection modules are projected.

[0040] The image processing and control unit 2 is the intelligent core that realizes "seamless splicing" and optimizes the display effect. The video signal splitter performs real-time and deterministic screen splitting of the input panoramic video signal based on the physical field of view (optical field of view) and splicing plan (calibrated overlapping area parameters) of the dual LBS projection units, and splits it into two sub-screen signals, left and right, in real time. The two sub-screen signals are input into the corresponding LBS projection modules.

[0041] The splicing area image processing module includes a geometric correction module and a fusion module. The geometric correction module is obtained by calibrating the projection optical system and the characteristics of the windshield surface. The geometric correction module is mainly based on the precise calibration parameters of the optical path of the dual LBS projection unit. It performs non-linear geometric distortion correction on the image pixels of the two sub-images, especially the overlapping area, to eliminate image deformation that may be caused by the optical projection angle and the curvature of the projection surface, and ensure that the two sub-images are geometrically precisely aligned.

[0042] The main function of the fusion module is to use a pixel-level gradient brightness and chromaticity fusion algorithm in the overlapping area. This fusion algorithm mainly calculates in real time in the overlapping area of ​​two images to make the brightness and chromaticity of the pixels on both sides of the center line of the overlapping area smoothly transition from the output of one LBS projection module to the output of another LBS projection module, avoiding harsh boundaries, thereby eliminating the "slap marks" of brightness and color difference that may be caused by the two independent RGB laser light source groups 11, and achieving visually seamless integration.

[0043] The synchronization controller generates a high-precision and low-jitter synchronization clock signal, which is simultaneously distributed to the control circuits of the two LBS projection modules to ensure absolute synchronization of their scanning actions. This is the timing guarantee for achieving pixel-level precise stitching and avoiding dynamic stitching marks.

[0044] This invention employs a splicing scheme of two LBS projection modules, fundamentally breaking through the bottleneck of the limited field of view of a single LBS projection module and successfully realizing the display of a panoramic large screen. At the same time, through the image processing and control unit 2, geometric correction and pixel-level brightness and color fusion of the overlapping area are performed, effectively eliminating the "splitting marks" problems such as uneven brightness, color difference (i.e., color difference) and geometric misalignment that are difficult to avoid in traditional multi-module splicing. Finally, a visually integrated, coherent and seamless high-quality virtual image is presented, greatly improving the immersive viewing experience and the integrity of information display.

[0045] Secondly, the use of special glass coated with a multi-layered optical anti-reflection film 32 as the projection surface greatly suppresses the reflection and glare of ambient light (especially strong sunlight) on the glass projection surface 3, improves the contrast of the displayed virtual image, and ensures that key driving information (such as vehicle speed and navigation arrows) can be clearly and conspicuously presented to the driver under various lighting conditions such as day and dusk, reducing information omissions or misjudgments caused by glare interference and enhancing driving safety.

[0046] The embodiments and / or implementation methods described above are merely preferred embodiments and / or implementation methods for implementing the technology of the present invention, and are not intended to limit the implementation methods of the technology of the present invention in any way. Any person skilled in the art can make some modifications or alterations to other equivalent embodiments without departing from the scope of the technical means disclosed in the content of the present invention, but they should still be regarded as the technology or embodiments that are substantially the same as the present invention.

[0047] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A panoramic head-up display device based on dual LBS projection, characterized in that, The system includes a dual LBS projection unit, a projection optical system, a glass projection surface (3), and an image processing and control unit (2). The dual LBS projection unit is used to emit two beams of three-color lasers and to perform two-dimensional deflection and modulation on the three-color lasers. The projection optical system has two beams and is used to collimate, expand, and correct aberrations of the corresponding three-color laser beams. The glass projection surface (3) receives the beams of three-color lasers to form sub-images with overlapping areas. The image processing and control unit (2) divides, corrects, and fuses the received panoramic video signal and generates two synchronous sub-image signals. The two sub-image signals drive the dual LBS projection unit to project the three-color laser beams. The glass projection surface (3) includes a glass substrate (31) and an optical anti-reflection film (32) located on the glass substrate (31).

2. The panoramic head-up display device based on dual LBS projection according to claim 1, characterized in that, The dual LBS projection unit includes two identical LBS projection modules capable of projecting sub-images. Each LBS projection module includes an RGB laser light source group (11), a micro scanning mirror (13), and a control and drive circuit. The RGB laser light source group (11) is used to emit three-color lasers, and the micro scanning mirror (13) is used to deflect the beam of the three-color lasers. The control and drive circuit is used to receive video signals and synchronization signals from the image processing and control unit, and synchronously drive the micro scanning mirror (13) to deflect along a predetermined trajectory. The LBS projection modules and the projection optics system together form an LBS projection system (1).

3. A panoramic head-up display device based on dual LBS projection according to claim 2, characterized in that, The two LBS projection modules are placed symmetrically, and the optical axes of the two LBS projection modules intersect in space.

4. A panoramic head-up display device based on dual LBS projection according to claim 2, characterized in that, The projection optical system is configured in correspondence with the LBS projection module. The projection optical system includes a collimating and beam-expanding lens group (12) and an objective lens group (14). The collimating and beam-expanding lens group (12) is used to collimate and expand the three-color laser beam emitted by the LBS projection module to form a parallel beam. The objective lens group (14) is used to guide the three-color laser beam that has passed through the collimating and beam-expanding lens group (12) to be projected onto a set projection area and to correct aberrations. The sub-images projected by the two LBS projection modules have a predetermined overlapping area on the glass projection surface (3) through the guidance of the projection optical system.

5. A panoramic head-up display device based on dual LBS projection according to claim 2, characterized in that, The image processing and control unit (2) includes a video signal splitter, a splicing area image processing module and a synchronization controller. The video signal splitter receives the panoramic video signal and splits the input panoramic video signal into two sub-screen signals in real time. The splicing area image processing module is used to perform geometric distortion correction on the sub-screens and eliminate the difference in brightness and color when the two LBS projection modules are projected.

6. A panoramic head-up display device based on dual LBS projection according to claim 5, characterized in that, The splicing area image processing module includes a geometric correction module and a fusion module. The geometric correction module is used to correct the geometric distortion of the two sub-images, and the fusion module is used to eliminate the difference in brightness and color when the two LBS projection modules are projected.

Images