HMD Display Orientation Control for Eye Strain Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional head-mounted displays (HMDs) cause discomfort and eyestrain due to non-orthogonal focal planes and lines of sight, imbalance in focusing, and differences in parallax and image blurring, which affect the natural perception of depth and distance in cross-reality systems.
Innovation Solution
A head-mounted display system with adjustable display devices and lenses that align the optical axis with the line of sight, maintaining an angle of approximately 90° at the intersection point, and using camera modules or image processing to replicate the focal planes and parallax of real-world observations, reducing optical aberrations and keeping images centered in the visual field.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the display device is positioned to provide a wide field of view, then the coverage area is improved, but the angle between the line of sight and display surface deviates from 90°, causing eyestrain and discomfort
Solution Approach 1:
The HMD system dynamically adjusts the display device position and orientation based on real-time line-of-sight detection. The driving mechanism moves the display device to maintain a 90° angle between the line of sight and display surface, while the focal point adjustment mechanism ensures continuous focus alignment, eliminating static positioning limitations
Solution Approach 2:
The system uses a line-of-sight detector to continuously monitor the user's gaze direction and provides feedback to the controller. The controller processes this information and adjusts the display device position and focal point accordingly, creating a closed-loop control system that maintains optimal viewing geometry
2Manufacturing precision
If the focal plane is adjusted to match the display surface, then the image sharpness is improved, but the parallax and depth perception become unbalanced, affecting natural cross-reality perception
Solution Approach 1:
The system dynamically changes multiple optical parameters simultaneously - the focal plane position, display surface orientation, and optical axis alignment - to maintain consistent parallax relationships and depth perception characteristics that match natural vision across different viewing conditions
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 significantly reduces eyestrain and discomfort by aligning the display with the user's line of sight, improving focus balance, and accurately replicating real-world depth perception, enhancing the cross-reality experience.
Implementation Method 1
an optical system configured to adjust a focal point of an eye of an observer to the display device
Implementation Method 2
a line-of-sight detector configured to detect a line of sight of the observer
Data Source
AI summary
A head mounted display includes a display device having a display surface, an optical system configured to adjust a focal point of an eye of an observer to the display device, a driving mechanism configured to drive the display device, a line-of-sight detector configured to detect a line of sight of the observer, and a controller configured to control, based on an output from the line-of-sight detector, the driving mechanism so that an angle formed by the line of sight and the display surface falls within a preset allowable range with respect to 90° at an intersection point of the line of sight and the display surface.