A topological photon AR / VR retina projection display engine based on projection geometry regulation and a control method thereof

Abstract

The application discloses a kind of topological photonic AR / VR retina projection display engine based on projection geometry regulation and control and control method thereof.The display engine includes semiconductor substrate, topological photonic crystal light engine array (honeycomb lattice structure, with non-zero topological Chen number), gate electrode array (applies gate voltage to independently regulate the projection angle of each light engine unit, the projection angle of each light engine unit is dynamically adjusted according to eye tracking data, so that the projection image is always aligned with the foveal region of retina, and the fixation point rendering is realized.The display engine judges the display state in real time according to the topological stability criterion during the working process.The application realizes the AR / VR near-eye display of ultra-thin (thickness), low power consumption (, large field of view (, high brightness (nit) and can be applied to AR glasses, VR head-mounted display, vehicle-mounted HUD and other scenes.

Description

Technical Field

[0001] This invention relates to the fields of augmented reality / virtual reality display technology and topological photonics, specifically to a topological photonic AR / VR retinal projection display engine and its control method based on projection geometry control. This invention can be applied to augmented reality (AR) glasses, virtual reality (VR) headsets, mixed reality (MR) devices, automotive head-up displays (HUDs), and smart helmet displays, and is particularly suitable for applications requiring ultra-thin, low-power, high-brightness, and wide-field-of-view near-eye displays. Background Technology

[0002] Augmented reality (AR) and virtual reality (VR) are core technologies for next-generation human-computer interaction, considered the next-generation computing platform after smartphones. The near-eye display engine is a core component of AR / VR devices, and its performance directly determines the device's size, weight, power consumption, and user experience. Existing AR / VR near-eye display technologies mainly face the following challenges: (a) Excessive volume and weight Traditional AR / VR display engines rely on complex optical lens groups, prisms, and mirrors, resulting in a bulky optical path. The Birdbath solution requires large-size semi-transparent and semi-reflective mirrors and curved mirrors, with optical module thicknesses typically exceeding 20mm. While waveguide solutions achieve thinner and lighter designs, their manufacturing processes are complex, yield rates are low, and they suffer from rainbow effects and uneven brightness. In existing solutions, the optical engine often occupies more than 60% of the AR glasses' volume, making them bulky and difficult to wear in everyday situations. (ii) High power consumption and short battery life Existing display engines (such as LCoS, DLP, and Micro-OLED) require backlighting or external light sources. LCoS and DLP require high-power LEDs or laser light sources, while Micro-OLED, although self-emissive, has low luminous efficiency. Overall power consumption is typically in the range of 1-3W, severely limiting the battery life of AR / VR devices and making it difficult to support all-day use. (iii) Limited field of view Existing AR display solutions present a fundamental contradiction between field of view and size. The Birdbath solution offers a field of view of 50-60° but is bulky; waveguide solutions (surface relief gratings or holographic gratings) typically limit the field of view to 30-50° and involve a trade-off between FOV and eye movement range; freeform surface solutions offer a moderate field of view but face challenges in aberration correction. Large field-of-view solutions are often bulky, limiting immersive experiences. (iv) Insufficient brightness AR devices need to operate in ambient light and require a display brightness of ≥1000 nits. Optical waveguide solutions typically have a coupling efficiency of only 1-5%, resulting in significant light energy loss; LCoS and DLP solutions also have optical efficiencies of only 10-20%. Existing solutions struggle to balance brightness and power consumption, leading to blurry displays in outdoor environments. (v) Lack of dynamic beam control capability Existing AR / VR display engines have a fixed beam direction, which cannot dynamically adjust the projection angle according to the eye position and gaze direction, thus limiting the improvement of display efficiency and user experience. (vi) The application of topological photonics in near-eye displays is still in its infancy. Topological photonic devices have demonstrated superior performance in optical communication and optical computing (topology-protected boundary states, high-Q resonant cavities, and low-loss waveguides), but they have not yet been applied to AR / VR near-eye display applications, lacking display engine solutions based on topology protection mechanisms. To address the aforementioned problems, this invention provides a topological photonic AR / VR retinal projection display engine and its control method based on projection geometry control. Summary of the Invention

[0003] (a) Purpose of the invention This invention aims to solve the technical problems of existing AR / VR near-eye display technologies, such as excessive size and weight, high power consumption, limited field of view, insufficient brightness, lack of dynamic control, and lack of application of topological photonics. It provides a topological photonic AR / VR retinal projection display engine and its control method based on projection geometry control. (II) Technical Solution This invention provides a topological photonic AR / VR retinal projection display engine based on projection geometry control, characterized in that it includes: A semiconductor substrate; A topological photonic crystal optical engine array, disposed on the semiconductor substrate, is composed of two or more materials with different dielectric constants arranged periodically in a honeycomb lattice, and has a non-zero topological Chern number. Used to generate and control the display beam; A gate electrode array, integrated on each optical engine unit of the topological photonic crystal optical engine array, is used to independently adjust the projection angle of each optical engine unit by applying a gate voltage. The projection angle Defined as , ; An image data interface for receiving external image data; An image processing and control module is connected to the image data interface and the gate electrode array, used to convert image data into driving signals for each optical engine unit and generate projection angle control schemes for each optical engine unit. An eye tracking module, connected to the image processing and control module, is used to detect the user's eye position and gaze direction in real time and generate a dynamic projection angle adjustment signal; A beam collimation and beam expansion module is connected to the output end of the topological photonic crystal optical engine array to collimate and expand the outgoing beam. Mathematical framework for projection geometry control: Definition of projection angle: The projection angle Defined as: in and These are the radial and axial projection weight components, respectively. Rate of change of projection angle: During retinal projection display, the projection geometry control module continuously monitors the dynamic rate of change of the projection angle. : when When the threshold is exceeded, it indicates that the display engine has been disturbed by external disturbances (head movement, eye movement, etc.), and the system will automatically trigger compensation. Topological stability criterion: The present invention uses the following stability criterion to determine whether the display state of the topological photonic crystal optical engine array is in a stable topological state: in Photon loss rate The rate of change of the projection angle. For topological Chern numbers, The coefficient of recovery, is Planck's constant. When the criterion is met, the display engine is in a stable topology state, and the image projection is stable and clear; when the criterion is not met, feedback adjustment is triggered (relocking the projection angle, adjusting the beam direction, etc.) to ensure display quality. Topological nontriviality condition: The condition for the topological photonic crystal optical engine array to be in a topologically nontrivial phase is: in For the theoretically optimal projection angle, For topology protection bandwidth. How does retinal projection work? The display beam generated by the topological photonic crystal optical engine array is directly projected onto the user's retina after passing through the beam collimation and beam expansion module, forming a clear image on the retina. The projection geometry control module dynamically adjusts the beam direction by controlling the projection angle of each optical engine unit in real time, ensuring that the projected image is always aligned with the fovea region of the user's retina, achieving foveal rendering and dynamic field of view expansion. Focal point rendering mechanism: Based on the gaze direction data provided by the eye-tracking module, the image processing and control module divides the displayed image into a gaze region (corresponding to the fovea) and a peripheral region. The gaze region is rendered at full resolution (4K), while the peripheral region is rendered at low resolution (720p). The high-resolution light beam is precisely directed to the fovea region of the retina through projection angle adjustment. This gaze-point rendering reduces the effective computational load by approximately 90%. Display performance parameters: Field of view: brightness: NEET Power consumption: Modulation rate: Resolution: per eye (III) Beneficial Effects Ultra-thin and lightweight structure: On-chip integrated light engine, eliminating the need for complex optical lens groups, AR glasses thickness can be reduced to less than 5mm; Ultra-low power consumption: Topological photonic devices do not require backlighting and directly modulate light emission, reducing power consumption by more than 80%; Ultra-wide field of view: Beam scanning is achieved by adjusting the projection angle, and the field of view can be extended to over 100°; Ultra-high brightness: The topology protection mechanism improves light efficiency, and the brightness can reach more than 2000 nits, making it clearly visible outdoors; Dynamic focal rendering: Eye tracking + projection angle adjustment, high-resolution rendering only in the focal area, improving computational efficiency by 10 times; Topology stability criterion: For the first time, a quantitative criterion for the topology stability of AR / VR display engines has been established to ensure display quality. Attached Figure Description

[0004] Figure 1 This is a schematic diagram of the overall structure of a topological photonic AR / VR retinal projection display engine based on projection geometry control, provided in an embodiment of the present invention. Figure 2 A schematic diagram of the retinal projection display principle (including human eye anatomy) provided for an embodiment of the present invention. Figure 3 This is a flowchart of eye tracking and dynamic projection angle adjustment provided for an embodiment of the present invention. Figure 4 This is a flowchart of display engine control and image processing provided in an embodiment of the present invention. Figure 5 This is a schematic diagram showing the installation position of the display engine in the AR glasses frame, as provided in an embodiment of the present invention. Detailed Implementation

[0005] Example 1: AR Retina Projection Display Engine Based on Projection Geometry Control Step 1: Fabrication of a topological photonic crystal optical engine array A topological photonic crystal optical engine array was fabricated on an SOI substrate. Electron beam lithography and ICP etching were used to fabricate an array with a non-zero topological Chern number. The topological photonic crystal structure operates over the visible light band. The RGB colors are generated by three subarrays with different lattice constants: red (620-750nm), green (495-570nm), and blue (450-495nm), with each subarray arranged in sections on the chip. Step 2: Integrated gate electrode array Gate electrodes are integrated on each optical engine unit, and the projection angle of each unit can be independently adjusted by applying a gate voltage (0-10V). The projection angle can be adjusted from 0.1 to 0.8 rad, with a high adjustment accuracy. . Step 3: Integrate beam collimation and beam expander module A beam collimation and beam expander module is integrated at the output end of a topological photonic crystal optical engine array. This module includes a microlens array or diffractive optical elements to collimate and expand the output beam, thereby reducing the divergence angle of the output beam. . Step 4: Integrate the eye-tracking module An eye-tracking camera and infrared LED illumination are integrated into the AR glasses frame to detect the user's pupil position and gaze direction in real time, with a sampling rate of [missing information]. Tracking accuracy . Step 5: Image Processing and Foveated Rendering The image processing and control module calculates the gaze point position based on eye-tracking data and divides the displayed image into a gaze region and a peripheral region. The gaze region is rendered at 4K resolution, while the peripheral region is rendered at 720p resolution, improving computational efficiency by approximately 10 times. Step 6: Dynamic projection angle adjustment The image processing and control module calculates the target projection angle of each optical engine unit based on the gaze point position. The gate electrode array performs modulation, precisely directing the high-resolution beam to the fovea region of the retina, while the peripheral beam covers other areas of the retina. Step 7: Stability Monitoring and Feedback During the display process, the rate of change of the projection angle is continuously monitored. The system calculates the topology stability criterion. When the criterion is not met, the system automatically adjusts the gate voltage to relock the projection angle, ensuring a stable and clear displayed image. Example 2: Wide Field of View Display Engine for VR Headsets Step 1: Expand the optical engine array The topological photonic crystal optical engine array is expanded to a higher density, achieving a single-eye pixel count of [number missing]. (4K), dual-eye independent drive. Step 2: Field of view expansion Rapid beam scanning is achieved by adjusting the projection angle, and the scanning frequency... The field of view expands to The above ensures that there is no noticeable flickering. Step 3: Performance Verification Actual measurement shows engine thickness Power consumption ,brightness NET, field of view This meets the immersive display requirements of VR headsets. Example 3: In-vehicle Head-Up Display (HUD) Application Step 1: Ambient Light Adaptive Configuration Configure the display engine to in-vehicle HUD mode, automatically adjusting display brightness based on ambient light sensor data: Daytime mode brightness. Nit, Night Mode Brightness NEET. Step 2: Adjusting the projection distance The equivalent projection distance of the beam can be adjusted (2-10 meters) by the projection geometry control module, so that the displayed content remains clear at different driving distances. Step 3: Adapting the driving view The eye-tracking module detects the driver's head posture and gaze direction, while the projection geometry control module automatically adjusts the projection angle to keep the displayed content in the center of the driver's field of vision, thus avoiding safety hazards caused by gaze deviation. Example 4: Smart Helmet Display (Outdoor High-Light Environment) Step 1: Ultra-high brightness configuration Configure the display engine to outdoor mode and increase the output brightness. NET ensures that the content is clearly visible even in direct sunlight. Step 2: Low-power standby During non-display periods, the topological photonic crystal optical engine array enters a low-power standby state, with standby power consumption... It can be worn all day long. Step 3: Ambient Light Adaptation An ambient light sensor monitors the ambient illuminance in real time and automatically adjusts the display brightness and contrast, adaptively switching between four scenarios: shadow, indoor, outdoor, and direct sunlight. Terminology Explanation

[0006] Terminology Meaning The projection angle (θ) is a geometric parameter describing the projection direction in fiber bundle projection mapping, where θ = arctan(β_s / β_r). Projection geometry control is a technique for precisely controlling a physical system by configuring the projection angle θ. Retinal projection projects a display beam directly onto the user's retina, forming an image on the retina. Focal point rendering is based on the user's gaze direction, rendering at high resolution only in the gaze area and at low resolution in the surrounding areas. Topological photonic crystal optical engines are based on arrays of luminescence and beam manipulation units of topological photonic crystals. Topology protection bandwidth (σ_θ) is the parametric width between nontrivial and trivial phases in the topology phase diagram. Topological stability criteria are quantitative criteria for determining whether a display state is in a stable topological state. The central region of the fovea retina, the highest resolution light-sensitive area, has a diameter of approximately 1.5 mm.

Claims

1. A topological photonic AR / VR retinal projection display engine based on projection geometry control, characterized in that, include: A semiconductor substrate; A topological photonic crystal optical engine array, disposed on the semiconductor substrate, is composed of two or more materials with different dielectric constants arranged periodically in a honeycomb lattice, and has a non-zero topological Chern number. Used to generate and control the display beam; A gate electrode array, integrated on each optical engine unit of the topological photonic crystal optical engine array, is used to independently adjust the projection angle of each optical engine unit by applying a gate voltage. The projection angle Defined as , ; An image data interface is used to receive external image data; An image processing and control module is connected to the image data interface and the gate electrode array, used to convert image data into driving signals for each optical engine unit and generate projection angle control schemes for each optical engine unit. An eye tracking module, connected to the image processing and control module, is used to detect the user's eye position and gaze direction in real time and generate a dynamic projection angle adjustment signal; A beam collimation and beam expansion module is connected to the output end of the topological photonic crystal optical engine array to collimate and expand the outgoing beam. During operation, the display engine dynamically adjusts the projection angle of each light engine unit based on eye-tracking data, ensuring that the projected image is always aligned with the fovea region of the user's retina.

2. The display engine according to claim 1, characterized in that: The image processing and control module renders the gaze point based on eye tracking data, rendering the gaze area at full resolution and the peripheral area at low resolution, and precisely guides the high-resolution beam to the fovea region of the retina by adjusting the projection angle.

3. The display engine according to claim 1, characterized in that: The condition for the topological photonic crystal optical engine array to be in a topologically nontrivial phase is: and ,in For the theoretically optimal projection angle, For topology protection bandwidth.

4. The display engine according to claim 1, characterized in that: The display engine operates based on topology stability criteria. Determine whether the displayed state is in a stable topological state, where Photon loss rate The rate of change of the projection angle. For topological Chern numbers, The coefficient of recovery, It is Planck's constant; feedback adjustment is triggered when the criterion is not met.

5. The display engine according to claim 1, characterized in that: The field of view of the display engine ,brightness nits, power consumption modulation rate resolution per eye.

6. The display engine according to claim 1, characterized in that: The gate voltage applied to the gate electrode array is in the range of 0-10V, and the projection angle adjustment accuracy is [not specified]. .

7. The display engine according to claim 1, characterized in that: The topological photonic crystal optical engine array comprises three sub-arrays, corresponding to red (620-750nm), green (495-570nm), and blue (450-495nm) wavelengths, respectively. Each sub-array is arranged in sections on the chip to achieve full-color display.

8. The display engine according to claim 1, characterized in that: The beam collimation and beam expanding module includes a microlens array or diffractive optical elements to adjust the divergence angle of the emitted beam. .

9. A topological photonic AR / VR retinal projection display method based on projection geometry control, characterized in that, Includes the following steps: (1) The image processing and control module receives external image data through the image data interface and converts the image data into drive signals for each optical engine unit; (2) The eye-tracking module detects the user's eye position and gaze direction in real time and generates gaze point coordinates; (3) The image processing and control module calculates the target projection angle of each optical engine unit based on the gaze point coordinates. ; (4) The gate electrode array applies a gate voltage to each photoengine unit, thereby adjusting the projection angle of each photoengine unit to... ; (5) The topological photonic crystal optical engine array generates a display beam, which is then collimated and expanded by the beam collimation and expansion module and projected onto the user's retina; (6) Continuously monitor the rate of change of the projection angle during the working process. According to the topological stability criterion Determine whether the displayed state is in a stable topological state; if the criterion is not met, trigger feedback adjustment.

10. The method according to claim 9, characterized in that: The image processing and control module in step (3) divides the display image into a gaze region and a peripheral region according to the gaze point coordinates. The gaze region is rendered at full resolution, and the peripheral region is rendered at low resolution. The gate voltage range in step (4) is 0-10V, and the projection angle of each optical engine unit is independently adjustable. The feedback adjustment in step (6) includes re-locking the projection angle or adjusting the beam direction.

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