Multi-focal AR Display with Eye Tracking for Vergence-Accommodation Conflict
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current augmented reality and virtual reality head-mounted displays suffer from eye fatigue and defocusing due to the inability to adjust focus according to the user's fixation depth, with existing solutions either reducing video frame rate or compromising image quality.
Innovation Solution
A multi-focal augmented reality device utilizing multiple image-providing devices at different depths and an eye tracking sensor to selectively drive only the closest image to the user's fixation point, employing a beam splitter and controller to synthesize images and adjust luminance ratios, thereby minimizing vergence-accommodation conflict and visual fatigue.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple image-providing devices are used to provide multiple focus planes, then focus adjustment capability is improved, but device complexity increases
Solution Approach 1:
The system segments the imaging function into multiple independent image-providing devices (first image-providing device and second image-providing device), each responsible for different focus planes. This segmentation enables the system to provide multiple focal depths without requiring a single complex adjustable lens system, thereby improving focus adaptability while managing device complexity through functional division.
Solution Approach 2:
The system dynamically switches between different image-providing devices based on the user's fixation depth detected by the eye tracking sensor. The controller activates only the relevant image-providing device corresponding to the current fixation point, enabling dynamic adaptation to varying focus requirements without maintaining all components in an active state, thus managing complexity through selective operation.
2Loss of information
If all image-providing devices are driven simultaneously, then complete image coverage is improved, but power consumption increases
Solution Approach 1:
Instead of driving all image-providing devices simultaneously, the system employs partial action by activating only the specific image-providing device that corresponds to the user's current fixation depth. The eye tracking sensor detects the fixation point, and the controller selectively drives only the relevant device, thereby maintaining complete functional coverage while significantly reducing power consumption compared to driving all devices at full capacity.
3Object-affected harmful factors
If eye tracking sensor and selective driving are implemented, then visual fatigue is reduced, but device complexity increases
Solution Approach 1:
The system implements a feedback loop where the eye tracking sensor continuously monitors the user's eye position and fixation depth, and the controller uses this feedback information to selectively activate the appropriate image-providing device. This feedback mechanism ensures that the displayed image always matches the user's focal point, eliminating vergence-accommodation conflict and reducing visual fatigue, while the automated feedback-driven control manages the added complexity through intelligent decision-making algorithms.
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 reduces visual fatigue and improves the convenience of using AR/VR HMDs by providing sharp, multi-focal images that match the user's focus, enhancing prolonged use and image quality.
Implementation Method 1
a beam splitter that matches travelling directions of the plurality of images by passing some of the plurality of images and reflecting the other images
Implementation Method 2
a beam splitter that synthesizes the images provided by the multi-focal display and the external image. The beam splitter may be disposed to reflect the images provided by the multi-focal display and to pass the external image
Data Source
AI summary
A multi-focal augmented reality device may include a multi-focal display that provides a plurality of images output from a plurality of image-providing devices and located at different depths and an augmented reality image synthesis device that synthesizes the plurality of images provided by the multi-focal display and an external image.