Eye Tracking Illumination Beam Shaping for Near-Eye Displays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing eye tracking systems in near-eye display devices face challenges in accurately directing illumination to the eye box due to the presence of corrective optical elements, leading to degraded performance and increased power consumption.
Innovation Solution
The implementation of an eye tracking system that includes an eye tracking camera and illuminator assemblies with a light source, a collimator, and a beam shaping element, such as a diffractive optical element, to provide beam-shaped infrared or near-infrared light directly to the eye box, bypassing corrective optical elements and optimizing illumination efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If corrective optical elements are used in near-eye display devices, then vision correction is achieved, but eye tracking illumination accuracy is degraded
Solution Approach 1:
The optical system is segmented into separate functional components: the corrective optical element and the eye tracking illumination system are separated, with the illumination system positioned to bypass the corrective element. This allows independent optimization of each subsystem, maintaining vision correction functionality while achieving accurate eye tracking illumination without interference.
Solution Approach 2:
A dedicated illumination optical path is introduced as an intermediary system that operates independently from the corrective optical path. The illumination system includes its own light source, collimator, and beam shaping elements positioned to deliver light directly to the eye box without passing through the corrective optical element, thus avoiding degradation of illumination accuracy.
2Use of energy by moving object
If traditional illumination systems are used, then simplicity is maintained, but power consumption increases
Solution Approach 1:
The illumination system utilizes beam shaping elements including diffractive optical elements that modify the spatial distribution and intensity parameters of the illumination beam. This enables more efficient light delivery to the eye box with reduced waste, lowering power consumption while the added optical components are miniaturized to maintain wearable form factor.
Solution Approach 2:
Traditional mechanical adjustment mechanisms for illumination alignment are replaced with optically-based beam shaping elements and fixed optical paths. The collimator and beam shaping elements provide precise optical control without requiring mechanical adjustment, reducing power consumption and improving reliability while the overall system complexity is managed through integrated design.
3Measurement precision
If beam shaping elements are added, then illumination precision is improved, but device complexity increases
Solution Approach 1:
Multiple optical functions are merged into integrated components: the collimator and beam shaping elements are positioned in sequence within a compact illumination assembly, and the beam shaping elements serve dual purposes of both shaping the beam and directing it to the correct location. This reduces the number of separate adjustable components while maintaining high illumination precision.
Solution Approach 2:
The illumination system transitions from two-dimensional planar illumination to three-dimensional controlled beam delivery using beam shaping elements. The diffractive optical elements and other beam shaping components create precise three-dimensional illumination patterns that accurately target the eye box, achieving high precision while the compact arrangement minimizes the physical footprint and overall device complexity.
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 eye tracking accuracy and speed while reducing power consumption by ensuring precise and focused illumination, thereby improving the overall performance and efficiency of near-eye display devices.
Implementation Method 1
a collimator, and a beam shaping element
Implementation Method 2
a beam shaping element, such as a diffractive optical element, to provide beam-shaped infrared or near-infrared light directly to the eye box
Implementation Method 3
a beam shaping element, such as a diffractive optical element
Data Source
AI summary
An eye tracking system includes, in addition an eye tracking camera, one or more illuminator assemblies. The illuminator assemblies include a light source (e.g., a light emitting diode (LED), a laser source, etc.) and provide infrared or near-infrared (NIR) light. The radiated light from the light source is received at and provided as a beam shaped light by a beam shaping element onto an eye box. A direction and/or a spread of beam shaped light is controlled by the beam shaping element. A collimator may be used between the light source and the beam shaping element to collimate the radiated light onto the beam shaping element for increase efficiency. The beam shaping element may be a diffractive optical element (DOE), with an angle and shape of diffractors selected based on a designated direction and spread of beam shaped light.