Holographic Light Guide Blur Compensation for Wider 3D Viewing
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Solution Overview
Problem
Current 3D image display methods, including glasses and non-glasses methods, are limited in increasing the number of viewpoints and can cause viewer fatigue due to discrepancies between perceived depth and eye focus, while existing holographic methods using computer-generated holograms suffer from image quality deterioration when viewed at varying distances.
Innovation Solution
A holographic display apparatus utilizing a light guide plate with diffractive optical elements and a spatial light modulator to generate and project 3D images, accompanied by an image processor that compensates for blur by adjusting the CGH signal based on depth and pixel spread, expanding the viewing window and improving image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a light guide plate with diffractive optical elements is used to expand the viewing window, then the viewing angle and number of viewpoints increase, but image quality deteriorates due to light loss and diffraction effects
Solution Approach 1:
The light guide plate is divided into multiple regions with different diffractive optical elements, each optimized for specific viewing angles. The plate contains multiple light extraction layers with varying grating patterns that segment the light path to maintain image quality across different viewing zones while expanding the overall viewing window.
Solution Approach 2:
Different regions of the light guide plate have locally optimized diffractive structures with varying pitch, depth, and orientation. The central region uses different parameters than the peripheral regions to maintain high image quality in the center while expanding peripheral viewing angles, addressing the local quality requirements of different viewing zones.
2Reliability
If computer-generated holograms are used for holographic display, then full parallax and depth perception are achieved, but image quality deteriorates when viewed at varying distances due to blur
Solution Approach 1:
The system pre-calculates and applies depth-based blur compensation to the computer-generated hologram before display. The image processor analyzes the 3D scene depth information and applies appropriate blur effects to objects at different depths, simulating natural depth perception while maintaining sharp focus for the intended viewing distance, thus preventing blur when viewed at varying distances.
Solution Approach 2:
The holographic display system dynamically adjusts the CGH parameters based on detected viewer distance and position. The image processor modifies the hologram in real-time to compensate for depth-induced blur, maintaining optimal image quality across varying viewing distances by dynamically changing the diffraction pattern parameters.
3Adaptability or versatility
If the viewing window is expanded to accommodate more viewpoints, then the number of visible perspectives increases, but the light intensity per viewpoint decreases
Solution Approach 1:
The system transitions from a 2D display plane to a 3D volumetric light distribution by using stacked light guide plates with different diffractive patterns. This adds a vertical dimension to light extraction, allowing multiple viewpoints to be served simultaneously without competing for the same light photons, thus maintaining light intensity while expanding the number of viewpoints.
Solution Approach 2:
The diffractive optical elements use variable pitch and depth parameters across different regions of the light guide plate. By changing these parameters, the system optimizes light direction and intensity distribution for each viewpoint region, ensuring that expanding the number of viewpoints does not uniformly reduce light intensity across all views.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The apparatus provides an expanded viewing window with improved 3D image quality by compensating for blur, allowing viewers to see holographic images without fatigue across a wider range and supporting augmented or mixed reality applications.
Implementation Method 1
the spatial light modulator may form a hologram pattern according to the input CGH signal and may diffract reference light using the hologram pattern to generate 3D images
Implementation Method 2
A holographic display apparatus utilizing a light guide plate with diffractive optical elements
Data Source
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AI summary
Provided a holographic display apparatus including a light guide plate including an input coupler and an output coupler, a holographic image generating assembly configured to generate a holographic image and provide the holographic image to the input coupler of the light guide plate, and an image processor configured to convert source image data based on a point spread function, which is obtained for each pixel of the holographic image on an image plane, to compensate for a blur of the holographic image output through the output coupler.