Light Field Display Device with Shutter Array for HMDs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current Head-Mounted Displays (HMDs) suffer from Vergence-Accommodation Conflict (VAC), leading to eye fatigue, headaches, and motion sickness due to inconsistencies in depth perception, making prolonged use challenging, especially in applications requiring detailed observation of complex three-dimensional structures.
Innovation Solution
A Light Field Display (LFD) device with a radiation angle resolution of ≤0.3°, implemented using a shutter-type LFD in HMDs, which includes an optical shutter array panel and eye-tracking sensors to adjust the light field ray group output based on user gaze and viewing distance, ensuring high 3D resolution and eliminating crosstalk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If binocular disparity method is used for 3D display, then depth perception is improved, but Vergence-Accommodation Conflict occurs causing eye fatigue and headaches
Solution Approach 1:
The patent changes the fundamental display parameter from binocular disparity to light field rendering, enabling both focal distance and convergence distance to be controlled independently and matched, thereby resolving VAC while maintaining depth perception
Solution Approach 2:
The patent adds the light field dimension to traditional stereoscopic display, controlling not only intensity and color but also the directional distribution of light rays, enabling simultaneous control of focus and convergence at different depths
2Measurement precision
If light field display with high angular resolution is implemented, then VAC is eliminated and 3D image quality is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent segments the display into multiple light shutter units, each controlling a specific angular range of light rays. This segmentation enables high angular resolution through coordinated control of multiple simple units rather than requiring a single complex high-resolution component
Solution Approach 2:
The patent replaces traditional mechanical optical elements with electrically controllable liquid crystal light shutters, enabling precise angular control through electrical signals rather than mechanical adjustments, thereby reducing device complexity
3Measurement precision
If multiple light shutters are used to form light field ray groups, then 3D resolution is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent incorporates feedback mechanisms that detect the actual positions and orientations of light shutters and elemental pixels, then dynamically adjust control parameters to compensate for manufacturing tolerances, enabling high 3D resolution without requiring extremely tight manufacturing precision
Solution Approach 2:
The patent performs preliminary characterization of each light shutter and pixel pair during assembly, storing their actual optical parameters for use in rendering calculations, thereby pre-compensating for manufacturing variations before the device is used
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 solution effectively eliminates VAC, providing high-fidelity, natural 3D images without eye strain, enabling comfortable use for extended periods and supporting applications requiring precise 3D observation, such as remote operations and medical tasks.
Implementation Method 1
Each of the multiple light shutters comprises a liquid crystal cell made up of a pair of opposing substrates with a liquid crystal layer sandwiched between them, a pair of polarizing plates, and a group of electrodes that can switch and apply a horizontal electric field and a vertical electric field to the liquid crystal layer
Data Source
AI summary
The present invention includes a three-dimensional (3D) image display device and a head-mounted display featuring a light-field image display comprising a display panel with a group of element pixels composed of multiple pixels displaying light field information, and a light shutter array panel capable of forming an aperture by opening and closing multiple light shutters. In the present invention, to address vergence-accommodation conflict (VAC), reduce crosstalk, improve viewing angles, and enhance 3D resolution, the light-field image display has a light field ray group with multiple radiation angles formed by the element pixel group and the aperture, wherein the resolution of the radiation angles of the light field ray group is 0.3° or less. It further comprises a padding pixel group with one or more pixels not displaying light field information around the element pixel group, and the light field ray group is output only within a central viewing angle range, while a two-dimensional image is output in angular ranges outside the central viewing angle.