Gaze Tracking Eyewear Using Multi-Angle Glint Detection
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Solution Overview
Problem
Traditional gaze tracking systems face challenges in accuracy due to the need for continuous head and eye tracking, especially with unobtrusive eyewear or headwear devices, as they struggle to account for individual anatomical variations and movements, leading to potential distortions and loss of tracking accuracy during wide-ranging eye movements.
Innovation Solution
The use of multiple eye-tracking cameras and illumination sources mounted on eyewear or headwear, which operate in a 'range-finder' mode to track glints from different angles, allowing for accurate reconstruction of eye movements in three dimensions and ensuring adequate illumination without shadows, thereby maintaining accurate gaze tracking even during significant head or eye movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple eye-tracking cameras and illumination sources are mounted on eyewear or headwear to track glints from different angles, then gaze tracking resolution and pointing accuracy are improved, but device complexity increases
Solution Approach 1:
The system divides the gaze tracking function into multiple independent cameras, each capturing eye features from different angles. Each camera operates semi-independently with its own illumination sources, allowing parallel processing of eye movement data to achieve three-dimensional reconstruction of eye movements and improve gaze tracking accuracy.
Solution Approach 2:
The patent transitions from two-dimensional eye tracking to three-dimensional eye movement reconstruction by adding depth information through multiple cameras positioned at different angles. This dimensional expansion enables accurate tracking of eye movements in all spatial directions, resolving the accuracy limitations of traditional single-angle systems.
2Reliability
If multiple illumination sources are used to fully illuminate the eye region, then tracking accuracy during eye movements is improved, but the number of components increases
Solution Approach 1:
The illumination system is segmented into multiple independent light sources positioned at different locations around the eye region. Each illumination source can be independently controlled and activated based on the specific tracking requirements, providing comprehensive coverage of the eye surface while allowing flexible system configuration.
Solution Approach 2:
Different illumination sources are strategically positioned to illuminate specific regions of the eye from different angles, ensuring that each area of the eye receives appropriate lighting for accurate feature detection. This localized illumination approach ensures reliable tracking across the full range of eye movements.
3Measurement precision
If continuous head and eye tracking is performed to account for anatomical variations and movements, then gaze tracking accuracy is improved, but processing requirements and system complexity increase
Solution Approach 1:
The system performs preliminary calibration to establish the geometric relationship between cameras, illumination sources, and the eye model before actual tracking begins. This pre-computed geometric information is stored and used during continuous tracking to rapidly calculate gaze positions without requiring complex real-time computations, thus maintaining accuracy while reducing processing complexity.
Solution Approach 2:
The system continuously monitors eye movements and adjusts the tracking parameters in real-time based on feedback from the multiple cameras. This feedback mechanism allows the system to compensate for anatomical variations and device movements dynamically, maintaining high accuracy without requiring overly complex processing 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
This approach enhances the resolution and pointing accuracy of gaze tracking, enabling robust and unobtrusive monitoring of eye movements, suitable for various applications including medical diagnostics, advertising, and computer gaming, by compensating for complex eye geometry and movements.
Implementation Method 1
one or more illumination sources mounted on the device within a field of view of an eye of a wearer wearing the device and oriented to illuminate the eye
Implementation Method 2
identify one or more glints reflected off the eye from the one or more illumination sources
Data Source
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AI summary
A system mounted within eyewear or headwear to unobtrusively produce and track reference locations on the surface of one or both eyes of an observer is provided to improve the accuracy of gaze tracking. The system utilizes multiple illumination sources and/or multiple cameras to generate and observe glints from multiple directions. The use of multiple illumination sources and cameras can compensate for the complex, three- dimensional geometry of the head and the significant anatomical variations of the head and eye region that occurs among individuals. The system continuously tracks the initial placement and any slippage of eyewear or headwear. In addition, the use of multiple illumination sources and cameras can maintain high-precision, dynamic eye tracking as an eye moves through its full physiological range. Furthermore, illumination sources placed in the normal line-of-sight of the device wearer increase the accuracy of gaze tracking by producing reference vectors that are close to the visual axis of the device wearer.