Corrector Plate for AR Head-Mounted Display Aberration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
VR/AR head-mounted displays with simple magnifiers face challenges in providing a wide field of view and high resolution while maintaining a compact size, as they often suffer from distortion and aberration issues, especially at the edge of the field of view, which can be mitigated by using correction maps but requires significant storage and processing power, or by using optical correctors to compensate for sub-optimal collimation.
Innovation Solution
Incorporating a corrector plate or a light field display between the collimator and eyepiece to pre-distort light and compensate for sub-optimal collimation at the edge of the field of view, allowing for optical correction of aberrations without the need for eye tracking systems or extensive pre-distortion correction maps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a simple magnifier with a long focal length lens is used to achieve a wide field of view and large eyebox, then the eyebox size and ease of eye alignment are improved, but the device becomes longer and larger, creating an uncomfortable moment that pulls the head-mounted display downward
Solution Approach 1:
The optical system is divided into multiple components: a collimator element for initial light collimation, and a corrector plate for correcting off-axis light aberrations. This segmentation allows the use of a shorter focal length collimator while maintaining wide field of view and large eyebox through optical correction, eliminating the need for a long focal length lens that would increase device length.
Solution Approach 2:
A corrector plate is introduced as an intermediary optical element between the collimator and the eyepiece. This corrector plate specifically addresses the sub-optimal collimation of off-axis light, enabling the system to achieve wide field of view and large eyebox with a compact design by correcting aberrations that would otherwise require a longer optical path.
2Length of stationary object
If the focal length is reduced to make the device more compact, then the device size is reduced, but the collimation of off-axis light becomes sub-optimal, causing distortion and aberration at the edge of the field of view
Solution Approach 1:
A corrector plate is introduced as an intermediary optical element between the collimator and the eyepiece. This corrector plate specifically addresses the sub-optimal collimation of off-axis light, enabling the system to achieve wide field of view and large eyebox with a compact design by correcting aberrations that would otherwise require a longer optical path.
Solution Approach 2:
The corrector plate is designed with varying thickness or curvature to provide different optical corrections for different regions of the field of view. It specifically targets and corrects the collimation issues in the off-axis regions while maintaining the performance of on-axis light, thereby improving overall image quality across the entire field of view without requiring a longer focal length.
3Manufacturing precision
If pre-distortion correction maps are used to correct distortion and aberration, then the image quality is improved, but significant storage and processing power are required to store and apply multiple correction maps for different eye positions
Solution Approach 1:
The patent replaces the computational approach (software-based pre-distortion correction maps requiring storage and processing) with an optical approach (hardware-based corrector plate). The corrector plate performs distortion and aberration correction through its physical optical properties, eliminating the need for storing and processing multiple correction maps while achieving the same image quality improvement.
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
This solution enables the creation of VR/AR displays with reduced distortion and aberration across the entire field of view, enhancing user experience by maintaining image clarity without the need for complex eye tracking systems or large storage requirements.
Implementation Method 1
a collimator element configured to collimate light emitted by the display
Implementation Method 2
a corrector plate disposed between the collimator element and an eyepiece, wherein the corrector plate compensates for sub-optimal collimation of off-axis light at an edge of a field of view
Data Source
AI summary
The embodiments herein use a corrector plate or a light field display in an AR/VR display device to compensate for sub-optimal collimation at the edge of the FOV. In one embodiment, the corrector plate is disposed between the collimator and the viewer so that the light at the edge of the FOV can be corrected so that the aberrations mentioned above do not occur. In another embodiment, rather than using a corrector plate, the AR/VR display device can include a light field display that can use color intensity to pre-distort emitted light to compensate for sub-optimal collimation at the edge of the FOV. In this manner, the AR/VR display device can mitigate aberrations or distortions as the user moves her eyes relative to the display device.