IR Illumination Module for Camera-Free MEMS Eye Tracking
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Solution Overview
Problem
Mixed-reality systems face user discomfort due to bulky eye tracking cameras positioned near the eyes, and there is a need to reduce the size of laser-based systems while maintaining effective eye tracking and iris recognition.
Innovation Solution
An IR illumination system using an integrated scanning waveguide display generates IR light, which is combined with RGB light, and uses photodetectors to capture reflected IR light for eye tracking and iris detection, eliminating the need for separate cameras and reducing the z-dimensional profile by redirecting light out of plane.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate eye tracking cameras are positioned near the user's eyes, then eye tracking and iris recognition can be performed, but user discomfort increases due to bulky hardware
Solution Approach 1:
The patent combines the eye tracking camera and IR illumination device into a single integrated module positioned at the nosepiece. This merging eliminates the need for separate bulky cameras near the eyes, reducing user discomfort while maintaining eye tracking and iris recognition functionality through the integrated components working together
Solution Approach 2:
The integrated nosepiece module serves multiple functions: it houses both the eye tracking camera and IR illumination device, enabling both eye tracking and iris recognition simultaneously. This multi-functionality reduces the overall number of components needed while achieving multiple detection goals without requiring separate hardware near the user's eyes
2Reliability
If traditional laser-based eye tracking systems are used, then eye tracking can be performed, but the system size increases
Solution Approach 1:
The patent nests the IR illumination device and eye tracking camera within the existing nosepiece structure of the HMD. This nesting approach integrates the laser-based eye tracking components into the available space at the nosepiece, significantly reducing the overall system volume while maintaining full eye tracking capability
Solution Approach 2:
The patent positions the IR illumination device to emit light at an angle rather than directly forward, utilizing three-dimensional spatial arrangement within the nosepiece. This angular positioning allows the illumination path to be compact while still effectively illuminating the user's eyes for tracking, reducing the z-dimensional profile of the system
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 reduces user discomfort by using integrated components for eye tracking and iris detection, minimizing hardware size, and achieving accurate eye tracking and iris recognition without bulky cameras.
Implementation Method 1
An infrared (IR) illumination device 410 and a second collimating optic 425 are provided. The IR illumination device 410 generates IR light 415
Implementation Method 2
One or more (e.g., or a plurality such as an array of) photodetector(s) 485A-485B are configured to capture reflected IR light 480A-480B that is reflected by a user's eye 475
Implementation Method 3
A turning optic 420 is provided to redirect the IR light 415 in a direction out of plane relative to an emission orientation of the IR illumination device 410
Implementation Method 4
The IR illumination device 410 is associated with a second collimating optic 425
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
An improved eye tracking illumination system is disclosed. The system includes (i) an RGB laser device that is associated with a first collimating optic and (ii) an IR illumination device that is associated with a second collimating optic. The system also includes a DMA that has a MEMS mirror system. The DMA optically combines IR light and RGB light to generate combined light. The combined light is then directed towards a user's eye via a transport medium (e.g., a waveguide). One or more photodetector(s) are positioned to capture reflected light that is reflected off of the user's eye. The photodetectors include an IR detector configured to detect reflected IR light off of the user's eye in order to perform eye tracking.