Glass-based mini LED naked eye 3D transparent display and implementation method

Abstract

The application discloses a glass-based Mini LED naked-eye 3D transparent display and an implementation method thereof. The display comprises a transparent display image source module, a spatial light modulation module, a viewpoint tracking module and a control system. The spatial light modulation module is arranged on the light-emitting side of the transparent display image source module. The viewpoint tracking module comprises one or more high-precision cameras arranged around the display. The transparent display image source module, the spatial light modulation module and the viewpoint tracking module are electrically connected with the control system. The high transmittance of the display area is ensured by the transparent glass substrate and the micro-LED array, so that the display is nearly transparent when it is turned off or displays dark field content. The integrated SLM and viewpoint tracking system realizes excellent multi-view naked-eye 3D effect, and simultaneously realizes high-quality transparent display and naked-eye 3D display, achieving two goals at one stroke.

Description

Technical Field

[0001] This invention discloses a glass-based Mini LED naked-eye 3D transparent display and its implementation method, particularly a display architecture that combines transparent display technology and multi-viewpoint naked-eye 3D display technology, belonging to the field of display technology. Background Technology

[0002] With the continuous development of display technology, people have higher and higher requirements for the performance of displays. They not only pursue high resolution, high brightness and high contrast, but also have more demands for 3D display effects and transparency.

[0003] Existing glasses-free 3D display technologies are mainly divided into light barrier type, lenticular lens type, and directional backlight type. These technologies typically require adding an optical structure (such as a parallax barrier or microlens array) in front of the display panel to project images from different viewing angles to the observer's left and right eyes respectively, thereby achieving stereoscopic vision. However, these methods generally suffer from problems such as resolution loss, limited viewing angle, and reduced brightness. Meanwhile, transparent display technologies mostly use OLED or transparent LCD, but they face challenges in achieving high-brightness, high-contrast glasses-free 3D displays. In recent years, some research has also attempted to use spatial light modulators (SLMs) for light field displays or holographic displays to achieve better 3D effects, but these systems are often complex, costly, and difficult to simultaneously achieve high-quality transparent display functionality. The current technical shortcomings are mainly as follows: 1. Traditional naked-eye 3D technologies (such as lenticular lenses and parallax barriers) cause the physical resolution of the display panel to be divided in the horizontal direction by the number of viewpoints, resulting in a significant decrease in the image resolution seen by a single viewpoint.

[0004] 2. Existing technologies typically have a narrow field of view, requiring the observer to be located in a specific "optimal viewing area" to obtain a good 3D effect, and crosstalk is easily generated when moving.

[0005] 3. Most glasses-free 3D display devices do not have transparent display capabilities, or sacrifice key indicators such as display brightness and contrast in order to achieve transparency.

[0006] 4. Existing transparent 3D display solutions struggle to achieve a good balance between the number of viewpoints, the range of viewing angles, and the display resolution. Summary of the Invention

[0007] To address the shortcomings of existing transparent 3D display solutions mentioned above, which struggle to achieve a good balance between the number of viewpoints, viewing angle range, and display resolution, this invention provides a glass-based Mini LED naked-eye 3D transparent display and its implementation method. It employs a transparent display image source module, a spatial light modulation module, a viewpoint tracking module, and a control system. Utilizing the principle of "time multiplexing," it can simultaneously achieve the technical challenge of high-quality transparent display and high-resolution, multi-viewpoint, and wide-view naked-eye 3D display.

[0008] The technical solution adopted by the present invention to solve its technical problem is: a glass-based Mini LED naked-eye 3D transparent display, the display includes a transparent display image source module, a spatial light modulation module, a viewpoint tracking module and a control system. The spatial light modulation module is set on the light-emitting side of the transparent display image source module. The viewpoint tracking module includes one or more high-precision cameras set around the display. The transparent display image source module, the spatial light modulation module and the viewpoint tracking module are electrically connected to the control system.

[0009] A method for implementing a glass-based Mini LED naked-eye 3D transparent display as described above, the method comprising the following steps: Step S1: The control system receives viewpoint coordinate data from the viewpoint tracking module and performs calculations based on the preset 3D content and the "time reuse" algorithm. Step S2: The output of the control system is divided into two paths: one path controls the ultra-high-speed drive system of the transparent display image source module, which rapidly switches the display of image subframes corresponding to different viewpoints in time sequence within a single frame period; the other path synchronously controls the ultra-high-speed drive system of the spatial light modulation module, so that the modulation state of the SLM is strictly synchronized with the image subframes of the display image source.

[0010] The technical solution adopted by the present invention to solve its technical problem further includes: The transparent display image source module uses high-transmittance transparent glass as a substrate. On the glass substrate, a thick copper metal trace layer is fabricated using semiconductor technology, with a trace layer thickness of 5-10μm.

[0011] Multiple display units are arranged in an array on the substrate. Each display unit adopts MIP packaging technology and integrates red, green and blue micro LED chips as a pixel.

[0012] The spatial light modulation module is bonded to the light-emitting side of the transparent display image source module. The overall structure of the spatial light modulation module is a stacked flat plate structure, consisting of, from top to bottom: optical protective glass, transparent electrode layer, ultra-high response liquid crystal modulation layer, transparent driving circuit, lower glass substrate, and optical bonding adhesive layer.

[0013] The viewpoint tracking module includes an external visual acquisition component consisting of a high-precision camera, an image acquisition motherboard, and an image processing chip. The camera is fixedly installed in a fixed position around the display, and the image processing chip is set on the image acquisition motherboard. The video information acquired by the camera is output to the image processing chip for processing.

[0014] The viewpoint tracking module uses a camera to capture real-time images of the observer's face and eyes. It identifies pupils, eye sockets, and facial feature points through deep learning visual algorithms. Combined with the principle of binocular parallax ranging, it calculates the X, Y, and Z coordinates of the human eye in three-dimensional space. The position data is transmitted to the control system in real time to provide the target position for beam deflection of the spatial light modulator, thereby realizing naked-eye 3D imaging that follows the human eye.

[0015] The beneficial effects of this invention are: This invention solves the problems of traditional cylindrical lens naked-eye 3D display solutions that require a physical display screen, have poor 3D effects, are prone to dizziness, and have a small viewing angle. It truly realizes a holographic naked-eye 3D display function with many advantages such as media-free display, good 3D effects, simple structure, high brightness, and high contrast.

[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention ensures high transmittance of the display area through transparent glass substrate and micro LED array, making the display almost transparent when it is turned off or when displaying dark content; while the integrated SLM and viewpoint tracking system achieve excellent multi-viewpoint naked-eye 3D effect, achieving both high-quality transparent display and naked-eye 3D display at the same time.

[0017] (2) The present invention adopts the principle of "time multiplexing". The image seen by each viewpoint comes from the full resolution output of the display image source, but is allocated sequentially in time. Therefore, it fundamentally avoids the resolution loss problem caused by light splitting in traditional multi-viewpoint 3D technology and maintains high resolution.

[0018] (3) Since SLM can perform ultra-high-speed and precise directional control of light, combined with real-time viewpoint tracking, the system of the present invention can generate and project exclusive parallax images for observers in different spatial positions. This not only supports multiple viewpoints (which can be extended to multiple viewers), but also effectively expands the comfortable 3D viewing angle by dynamically adjusting the light path. Observers can still obtain good stereoscopic vision even when moving within a certain range, with multiple viewpoints and a wide viewing angle.

[0019] (4) The present invention uses Mini LED / Micro LED as the image source, which has the advantages of high brightness, high contrast, high color gamut and long life; thick copper traces and ultra-high speed driving system ensure high refresh rate and high current driving capability, making 3D images more stable and flicker-free, with excellent display performance.

[0020] (5) This invention organically integrates multiple advanced technologies (transparent display, high-speed LED, high-speed SLM, real-time tracking) to form a complete solution that can be applied to multiple fields such as high-end commercial windows, automotive head-up displays (HUD), museum exhibitions, and immersive entertainment equipment. It has a high degree of system integration and broad application prospects.

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the system architecture of the present invention.

[0023] Figure 2 This is a schematic diagram illustrating the principle of the transparent 3D display technology of the present invention.

[0024] Figure 3 This is a schematic diagram of multi-view image processing in the SLM system of this invention. Detailed Implementation

[0025] This embodiment is a preferred embodiment of the present invention. All other embodiments that are the same as or similar to this embodiment in principle and basic structure are within the protection scope of the present invention.

[0026] Please refer to the appendix for details. Figure 1 Appendix Figure 2 and attached Figure 3 This invention primarily protects a glass-based Mini LED naked-eye 3D transparent display, which mainly includes a transparent display image source module, a spatial light modulation module, a viewpoint tracking module, and a control system. The spatial light modulation module is located on the light-emitting side of the transparent display image source module, and the viewpoint tracking module includes one or more high-precision cameras located around (e.g., above) the display. The transparent display image source module, the spatial light modulation module, and the viewpoint tracking module are electrically connected to the control system.

[0027] In this embodiment, the transparent display image source module uses high-transmittance transparent glass as a substrate. On this glass substrate, a thick copper metal trace layer is fabricated using semiconductor technology to carry high current and achieve ultra-high-speed signal transmission. In this embodiment, the metal traces are fabricated on the glass substrate, with copper being the preferred material. The traces need to be thick, typically reaching a thickness of 5-10 μm.

[0028] In practice, multiple signal lines and LED pads are designed on the glass substrate. At the same time, no traces are designed in certain parts of the pixel area to allow natural light to pass through and achieve a transparent display effect. The trace layer process uses semiconductor evaporation and electroplating to thicken the copper layer in order to increase the trace cross-sectional area.

[0029] In this embodiment, multiple display units are arranged in an array on the substrate. Each display unit adopts MIP (MicroLED in Package, a packaging technology in which micro LED chips are first packaged and tested on a carrier board to form an easily integrated package, and then transferred to the display backplane) packaging technology. It integrates red (R), green (G), and blue (B) micro LED (MiniLED or Micro LED, refers to light-emitting diodes with a size in the range of tens to hundreds of micrometers. Micro LED usually refers to LEDs with a size of less than 100μm, which have the characteristics of self-illumination, high efficiency, and high brightness) chips as a pixel. The MIP is soldered to the pads by die bonding.

[0030] All pixels are driven by an ultra-high-speed driving system, which can employ PWM or a combination of PWM and PAM. This system can refresh image data at a refresh rate far exceeding that of conventional displays (e.g., ≥240Hz), providing a foundation for subsequent "time multiplexing." Conventional displays typically have a refresh rate of 60Hz; in this invention, frequencies exceeding 60Hz are defined as ultra-high-speed refresh frequencies.

[0031] The transparent display image source module is used to generate high-brightness, high-contrast transparent two-dimensional image light sources, and outputs multiple parallax images at an ultra-high refresh rate, providing an image basis for time-multiplexed naked-eye 3D.

[0032] In this embodiment, the spatial light modulation module is bonded to the light-emitting side of the transparent display image source module, belonging to the rear optical control layer. The overall structure of the spatial light modulation module is a stacked flat panel structure, consisting of, from top to bottom: optical protective glass, transparent electrode layer, ultra-high response liquid crystal modulation layer, transparent driving circuit, lower glass substrate, and optical bonding adhesive layer. The optical protective glass serves as a cover plate, protecting the characteristics and lifespan of the liquid crystal material; the transparent electrode layer and transparent driving circuit serve as the upper and lower electrodes of the liquid crystal modulation layer, providing electrical control driving signals; the ultra-high response liquid crystal modulation layer serves as the core functional layer, capable of wavefront modulation of the light from the image source module, and is a key functional layer for realizing 3D display; the lower glass substrate serves as a carrier substrate supporting the other layers; and the optical bonding layer acts as an adhesive to bond the image source module and the spatial light modulation module together.

[0033] In this embodiment, the core device of the spatial light modulation module is a Fourier spatial light modulator (SLM, a device capable of two-dimensional spatial modulation of one or more characteristics of light waves (such as amplitude, phase, polarization state). In this invention, it specifically refers to a phase-type SLM based on liquid crystal materials, used to modulate the phase of light waves to change the direction of light propagation. The core of the SLM is a modulation layer containing a layer of ultra-high response speed (this only refers to a liquid crystal material with a very fast response speed; a response speed that matches the aforementioned refresh rate can be defined as ultra-high speed response speed) liquid crystal material (such as ferroelectric liquid crystal or blue phase liquid crystal). The SLM is also equipped with an ultra-high speed driving system, whose function is to dynamically change the arrangement state of liquid crystal molecules according to control signals, thereby precisely modulating the wavefront of the light wave from the display image source that passes through it, changing the direction of light propagation, and achieving directional deflection of the beam. The working principle of the spatial light modulation module: Imaging light emitted from the transparent display image source is incident perpendicularly onto this module. The high-speed deflection of liquid crystal molecules changes the refractive index distribution, thus modulating the phase of the incident light wavefront. Based on the Fourier principle of optical diffraction, light waves with different phase distributions diffract and refract in space, thereby precisely controlling the emission angle of each pixel beam. Combined with an ultra-high refresh rate image source, the beam direction is dynamically switched, allowing images with different parallax to be projected onto different viewing positions of the human eye, achieving naked-eye stereo imaging.

[0034] The functions that the spatial light modulation module can achieve include: (1) wavefront shaping of the light emitted from the transparent image source; (2) dynamic and continuous change of the light propagation direction to achieve controllable beam deflection; (3) time multiplexing multi-viewpoint imaging in conjunction with ultra-high refresh rate; (4) maintaining high transmittance without damaging the transparent display effect.

[0035] In this embodiment, the viewpoint tracking module includes one or more high-precision cameras disposed around (e.g., above) the display. These cameras are used to capture the facial or eye features of an observer (which may be one or more) in real time. The viewpoint tracking module is an external visual acquisition component, consisting of a high-precision camera, an image acquisition motherboard, and an image processing chip. The camera is fixedly mounted in the display's external components, and the image processing chip is disposed on the image acquisition motherboard. The video information acquired by the camera is output to the image processing chip for processing.

[0036] The system uses a camera to capture real-time images of the observer's face and eyes. It then uses deep learning visual algorithms to identify pupils, eye sockets, and facial feature points. Combined with the principle of binocular parallax ranging, it calculates the X, Y, and Z coordinates of the human eye in three-dimensional space. The position data is transmitted to the control system in real time to provide the target position for beam deflection of the spatial light modulator, thus realizing naked-eye 3D imaging that follows the human eye.

[0037] The viewpoint tracking module can achieve: (1) real-time capture of the observer's eye position; (2) output of high-precision three-dimensional spatial viewpoint coordinates; (3) the control system provides dynamic tracking data to complete the adaptive following of the beam; and (4) realize multi-person, multi-angle synchronous naked-eye 3D viewing.

[0038] This invention also protects a method for realizing a glass-based Mini LED naked-eye 3D transparent display, the method comprising the following steps: Step S1: The control system receives viewpoint coordinate data from the viewpoint tracking module and performs calculations based on preset 3D content (multi-viewpoint image sequence) and the "time multiplexing" algorithm.

[0039] Step S2: The output of the control system is divided into two paths: one path controls the ultra-high-speed drive system of the transparent display image source module, which rapidly switches the display of image subframes corresponding to different viewpoints in time sequence within a single frame period; the other path synchronously controls the ultra-high-speed drive system of the spatial light modulation module, so that the modulation state of the SLM is strictly synchronized with the image subframes of the display image source.

[0040] Specifically, when the display source shows a subframe image of the Nth viewpoint, the control system controls the SLM to precisely deflect the light emitted from that subframe image to the spatial position of the Nth viewpoint. Due to the extremely fast switching speed (e.g., completing the loop of all viewpoint subframes within 1 / 60 of a second), utilizing the persistence of vision in the human eye, the observer will see a continuous, complete, and high-resolution 3D image at each viewpoint position.

[0041] The entire display architecture maintains high transparency in non-display areas.

[0042] This invention solves the problems of traditional cylindrical lens naked-eye 3D display solutions, such as the need for a physical display screen, poor 3D effect, easy dizziness, and small viewing angle. It truly realizes a holographic naked-eye 3D display function with many advantages, such as media-free display, good 3D effect, simple structure, high brightness, and high contrast.

[0043] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention ensures high transmittance of the display area through transparent glass substrate and micro LED array, making the display almost transparent when it is turned off or when displaying dark content; while the integrated SLM and viewpoint tracking system achieve excellent multi-viewpoint naked-eye 3D effect, achieving both high-quality transparent display and naked-eye 3D display at the same time.

[0044] (2) The present invention adopts the principle of "time multiplexing". The image seen by each viewpoint comes from the full resolution output of the display image source, but is allocated sequentially in time. Therefore, it fundamentally avoids the resolution loss problem caused by light splitting in traditional multi-viewpoint 3D technology and maintains high resolution.

[0045] (3) Since SLM can perform ultra-high-speed and precise directional control of light, combined with real-time viewpoint tracking, the system of the present invention can generate and project exclusive parallax images for observers in different spatial positions. This not only supports multiple viewpoints (which can be extended to multiple viewers), but also effectively expands the comfortable 3D viewing angle by dynamically adjusting the light path. Observers can still obtain good stereoscopic vision even when moving within a certain range, with multiple viewpoints and a wide viewing angle.

[0046] (4) The present invention uses Mini LED / Micro LED as the image source, which has the advantages of high brightness, high contrast, high color gamut and long life; thick copper traces and ultra-high speed driving system ensure high refresh rate and high current driving capability, making 3D images more stable and flicker-free, with excellent display performance.

[0047] (5) This invention organically integrates multiple advanced technologies (transparent display, high-speed LED, high-speed SLM, real-time tracking) to form a complete solution that can be applied to multiple fields such as high-end commercial windows, automotive head-up displays (HUD), museum exhibitions, and immersive entertainment equipment. It has a high degree of system integration and broad application prospects.

Claims

1. A glass-based Mini LED naked-eye 3D transparent display, characterized in that: The display includes a transparent display image source module, a spatial light modulation module, a viewpoint tracking module, and a control system. The spatial light modulation module is located on the light-emitting side of the transparent display image source module. The viewpoint tracking module includes one or more high-precision cameras located around the display. The transparent display image source module, the spatial light modulation module, and the viewpoint tracking module are electrically connected to the control system.

2. The glass-based Mini LED naked-eye 3D transparent display according to claim 1, characterized in that: The transparent display image source module uses high-transmittance transparent glass as a substrate. On the glass substrate, a thick copper metal trace layer is fabricated using semiconductor technology, with a trace layer thickness of 5-10μm.

3. The glass-based Mini LED naked-eye 3D transparent display according to claim 2, characterized in that: Multiple display units are arranged in an array on the substrate. Each display unit adopts MIP packaging technology and integrates red, green and blue micro LED chips as a pixel.

4. The glass-based Mini LED naked-eye 3D transparent display according to claim 1, characterized in that: The spatial light modulation module is bonded to the light-emitting side of the transparent display image source module. The overall structure of the spatial light modulation module is a stacked flat plate structure, consisting of, from top to bottom: optical protective glass, transparent electrode layer, ultra-high response liquid crystal modulation layer, transparent driving circuit, lower glass substrate, and optical bonding adhesive layer.

5. The glass-based Mini LED naked-eye 3D transparent display according to claim 1, characterized in that: The viewpoint tracking module includes an external visual acquisition component consisting of a high-precision camera, an image acquisition motherboard, and an image processing chip. The camera is fixedly installed in a fixed position around the display, and the image processing chip is set on the image acquisition motherboard. The video information acquired by the camera is output to the image processing chip for processing.

6. The glass-based Mini LED naked-eye 3D transparent display according to claim 5, characterized in that: The viewpoint tracking module uses a camera to capture real-time images of the observer's face and eyes. It identifies pupils, eye sockets, and facial feature points through deep learning visual algorithms. Combined with the principle of binocular parallax ranging, it calculates the X, Y, and Z coordinates of the human eye in three-dimensional space. The position data is transmitted to the control system in real time to provide the target position for beam deflection of the spatial light modulator, thereby realizing naked-eye 3D imaging that follows the human eye.

7. A method for implementing a glass-based Mini LED naked-eye 3D transparent display as described in any one of claims 1 to 6, characterized in that: The method includes the following steps: Step S1: The control system receives viewpoint coordinate data from the viewpoint tracking module and performs calculations based on the preset 3D content and the "time reuse" algorithm. Step S2: The output of the control system is divided into two paths: one path controls the ultra-high-speed drive system of the transparent display image source module, which rapidly switches the display of image subframes corresponding to different viewpoints in time sequence within a single frame period; the other path synchronously controls the ultra-high-speed drive system of the spatial light modulation module, so that the modulation state of the SLM is strictly synchronized with the image subframes of the display image source.

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