Stereoscopic Display Pupil Tracking Depth Adjustment

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Solution Overview

Problem

Current 3D display systems face challenges in accurately positioning virtual imagery with regard to depth, particularly due to moment-to-moment changes in the wearer's focal point, which affects the precise rendering of virtual objects in stereoscopic environments.

Innovation Solution

A method for a head-mounted stereoscopic display system that illuminates specific pixels in a display matrix based on the pupil position, forming virtual images in a plane in front of the eye on a straight line through the pupil, allowing the system to track changes in pupil position and adjust the depth coordinate of virtual imagery accordingly, using a combination of eye-tracking and predictive models to estimate pupil positions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a fixed focal plane is used for displaying virtual imagery, then the display system is simpler to implement, but the positioning accuracy of virtual imagery deteriorates when the user's focal point changes

Engineering Contradiction:
Improvedisplay system complexityVSAvoidvirtual imagery positioning accuracy
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent implements dynamic adjustment of the display system by tracking the user's pupil position in real-time and recalculating the virtual image coordinates based on the current focal point. This allows the system to adapt to moment-to-moment changes in the user's gaze, maintaining accurate virtual imagery positioning without requiring a completely complex redesign of the display architecture

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system incorporates feedback mechanisms by continuously monitoring the user's pupil position through eye-tracking technology and using this information to adjust the virtual image display parameters. This closed-loop feedback ensures that the virtual imagery remains accurately positioned relative to the user's actual focal point, resolving the contradiction between system simplicity and positioning accuracy

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If eye-tracking technology is implemented to track pupil position, then the positioning accuracy of virtual imagery improves, but the device complexity increases

Engineering Contradiction:
Improvevirtual imagery positioning accuracyVSAvoiddisplay system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent uses the pupil position as an intermediary measurement that bridges the user's natural gaze behavior and the digital display system. By tracking this intermediate parameter and using it to calculate adjusted virtual image coordinates, the system achieves high positioning accuracy without requiring direct manipulation of the user's eye movements or complex mechanical adjustments to the display hardware

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system replaces complex mechanical adjustment mechanisms with optical and computational methods. Instead of physically moving display components to track eye movements, the patent uses eye-tracking technology combined with software-based coordinate transformation to achieve the same effect, thereby improving accuracy while managing device complexity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If virtual imagery is positioned based on a predetermined focal plane, then the system is easier to operate, but the realism and immersion of the 3D experience deteriorates

Engineering Contradiction:
Improvesystem operation simplicityVSAvoiddepth perception accuracy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system performs preliminary calculations of virtual image coordinates based on the user's current pupil position before rendering the display. By pre-adjusting the image positions according to the tracked gaze direction, the system maintains operational simplicity while ensuring that the virtual imagery is correctly positioned to create accurate depth perception and immersion

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent dynamically changes the display parameters, specifically the coordinates where virtual images are rendered, based on the user's pupil position. This parameter adjustment allows the system to maintain ease of operation by automatically adapting to user gaze without requiring manual intervention, while simultaneously improving depth perception accuracy by keeping virtual imagery correctly positioned relative to the actual focal point

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3108292B1Stereoscopic display responsive to focal-point shift
Publication Date: 2023.07.12 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP3108292B1 patent drawingFigure 1
  • EP3108292B1 patent drawingFigure 2
  • EP3108292B1 patent drawingFigure 3

AI summary

A method for displaying virtual imagery on a stereoscopic display system having a display matrix. The virtual imagery presents a surface of individually renderable loci viewable to an eye of the user. The method includes, for each locus of the viewable surface, illuminating a pixel of the display matrix. The illuminated pixel is chosen based on a pupil position of the eye as determined by the stereoscopic display system. For each locus of the viewable surface, a virtual image of the illuminated pixel is formed in a plane in front of the eye. The virtual image is positioned on a straight line passing through the locus, the plane, and the pupil position. In this manner, the virtual image tracks change in the user's pupil position.