Head-Mounted Display Pixel Density Optimization via Aspheric Optics
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Solution Overview
Problem
Current head-mounted display (HMD) devices provide a large field of view but suffer from poor resolution due to constant pixel density distribution, which fails to align with human visual acuity, resulting in inadequate immersion and detail perception, especially in the peripheral vision area.
Innovation Solution
The display device optimizes pixel density by increasing it in the central area of the field of view and decreasing it in peripheral regions through a geometric transformation applied by the optics, coupled with an eye-tracking system to dynamically adjust the optical element's position and compensate for luminance variations, using a polynomial aspheric surface to modulate pixel density based on angular position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If constant pixel density distribution is used to provide a large field of view, then the field of view is increased, but the resolution in the central area is insufficient
Solution Approach 1:
The patent applies local quality by varying the pixel density across different regions of the display. The optical element is designed with a polynomial aspheric surface that creates non-uniform magnification, resulting in higher pixel density in the central field of view and lower pixel density in peripheral regions. This matches the human visual system's characteristics where central vision requires higher resolution while peripheral vision tolerates lower resolution.
Solution Approach 2:
The patent implements dynamics through the eye-tracking system that dynamically adjusts the displayed image based on the user's gaze position. The optical element's position is adjusted in response to eye movement, and the pixel density distribution is dynamically optimized to concentrate pixels in the foveal region where the user is currently looking, rather than using a static constant density distribution.
2Manufacturing precision
If pixel density is increased in the central area, then the resolution is improved, but the field of view is reduced
Solution Approach 1:
The polynomial aspheric surface of the optical element creates local quality variations in pixel density. By designing the surface with specific coefficients (e.g., z = c0 + c1*r^2 + c2*r^4 + c3*r^6), the system achieves higher pixel density in the central region while maintaining an extended field of view in peripheral regions. This allows simultaneous optimization of both resolution and field of view by matching pixel distribution to visual acuity requirements.
3Manufacturing precision
If the optical element's position is adjusted to track eye movement, then the pixel density alignment with visual acuity is improved, but the device complexity is increased
Solution Approach 1:
The patent implements feedback through an eye-tracking system that detects the user's gaze position and feeds this information back to the control system. The controller uses this feedback to dynamically adjust the optical element's position and modify the displayed image's pixel density distribution, ensuring that high-resolution regions are always aligned with the user's foveal vision. This closed-loop feedback mechanism optimizes pixel utilization while maintaining adaptability to user behavior.
Solution Approach 2:
The patent introduces an intermediary control system that mediates between the eye-tracking sensor and the optical element adjustment mechanism. This intermediary layer processes the eye position data and generates appropriate control signals to adjust the optical element's position and the image rendering parameters, thereby managing the complexity of coordinating multiple subsystems while achieving precise pixel density alignment.
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 enhances perceived pixel density near the optical axis, improving resolution and immersion by providing higher detail in the central gaze area while maintaining a large field of view, thus enhancing the overall user experience.
Implementation Method 1
a polynomial aspheric surface to modulate pixel density based on angular position
Data Source
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AI summary
A method for presenting an image on a display device (100) includes modifying the image by applying a geometric transformation to the image so that an area of the image on the display device is presented to a viewer with higher density of pixels than that in the rest of the image (S18).