Eye Tracking System Using Holographic Optical Element
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional eye tracking systems for wearable heads-up displays add unwanted bulk due to multiple dedicated components with stringent positioning requirements, increasing the size and form factor of the system.
Innovation Solution
An eye tracking system incorporating an infrared laser diode, optical scanner, holographic optical element, infrared detector, and infrared filter integrated into a transparent lens, with the holographic optical element and filter embedded or coupled to the lens, allowing for efficient redirection and filtering of infrared light without obstructing the user's view.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple dedicated components with stringent positioning requirements are used for eye tracking, then eye tracking functionality is achieved, but the size and form factor of the wearable heads-up display increase
Solution Approach 1:
The patent combines multiple eye tracking components (infrared laser diode, optical scanner, holographic optical element, infrared detector, and infrared filter) into a single integrated eye tracking device. This merging of components reduces the overall size and form factor while maintaining the necessary eye tracking functionality, directly resolving the technical contradiction between achieving reliable eye tracking and minimizing device volume.
2Measurement precision
If multiple dedicated components are used for eye tracking, then accurate eye position and orientation measurement is achieved, but the positioning requirements become more stringent and complex
Solution Approach 1:
The integration of all eye tracking components into a single device eliminates the need for multiple separate component positions, thereby reducing positioning requirements and structural complexity while maintaining measurement precision through the coordinated operation of integrated components.
Solution Approach 2:
The holographic optical element serves multiple functions: it redirects infrared light from the optical scanner to the eye, and also redirects reflected infrared light from the eye to the infrared detector. This multi-functionality reduces the number of separate optical components needed, simplifying the overall system structure and reducing positioning complexity.
3Object-affected harmful factors
If the infrared filter blocks infrared wavelengths, then unwanted infrared light is filtered out, but transmission of infrared light through the holographic optical element is affected
Solution Approach 1:
The infrared filter is positioned between the holographic optical element and the infrared detector, serving as an intermediary that selectively blocks unwanted infrared wavelengths (such as ambient infrared light) while allowing the desired infrared light from the eye to pass through to the detector, thus resolving the contradiction between filtering harmful infrared light and maintaining reliable infrared light transmission.
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 integration minimizes the impact on the size and form factor of wearable heads-up displays while effectively tracking eye position and orientation, enabling precise gaze direction measurement without interfering with the user's external environment.
Implementation Method 1
a holographic optical element positioned at the target area to receive the infrared light scanned by the optical scanner and to redirect the infrared light in a direction of the eye of the user
Implementation Method 2
an infrared filter disposed in a position to selectively block transmission of infrared wavelengths through the holographic optical element
Implementation Method 3
an infrared detector aligned to detect at least a portion of the infrared light returned from the eye
Implementation Method 4
an optical scanner positioned to receive the infrared light outputted by the at least one infrared laser diode and controllable to scan the infrared light over a target area
Data Source
AI summary
An eye tracking system for tracking an eye of a user includes at least one infrared laser diode to output an infrared light and an optical scanner positioned to receive the infrared light outputted by the at least one infrared laser diode and controllable to scan the infrared light over a target area. A holographic optical element is positioned at the target area to receive the infrared light from the optical scanner and redirect the infrared light to the eye of the user. An infrared detector is aligned to detect at least a portion of the infrared light returned from the eye of the user. An infrared filter is disposed in a position to selectively block transmission of infrared wavelengths through the holographic optical element from a side of the holographic optical element. An eyeglass lens, a wearable heads-up display, and a method of eye tracking are also described.