Transparent Capacitive Sensor for Contactless Eye Tracking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing eye tracking technologies either require physical contact with the eye or are cumbersome, lacking in portability and efficiency in detecting eye movements for applications such as drowsiness detection in drivers.
Innovation Solution
A contactless eye tracking apparatus using a transparent capacitive sensor supported by a wearable body, such as eyeglasses, that detects eye movements based on the electrostatic effect caused by the cornea bulge, with a driver to process signals and provide eye tracking data along with additional sensory information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a camera system is used to detect eye movements, then eye tracking can be achieved, but the device becomes cumbersome and lacks portability
Solution Approach 1:
The patent replaces the mechanical camera system with a capacitive sensing system that uses electrical fields to detect eye movements. The capacitive sensor detects changes in capacitance caused by the movement of the eye's cornea, eliminating the need for complex mechanical camera assemblies and enabling lightweight, portable integration into eyeglasses.
Solution Approach 2:
The patent changes the detection parameter from optical signals (camera-based) to electrical capacitance changes. By measuring capacitance variations between the sensor and the eye's cornea, the system achieves accurate eye tracking with a much simpler, lighter sensor that can be integrated into wearable eyeglasses.
2Measurement precision
If contact lenses or skin pads are used, then direct measurement is achieved, but the device requires physical contact with the eye
Solution Approach 1:
The patent uses the air gap between the eyeglass lens and the eye as an intermediary medium for capacitive coupling. The capacitive sensor detects eye movements through this non-contact medium by measuring changes in electrical field capacitance, eliminating the need for direct physical contact while maintaining measurement precision.
3Illumination intensity
If a transparent sensor is used, then visibility is maintained, but the sensor material selection becomes constrained
Solution Approach 1:
The patent employs transparent conductive materials such as indium tin oxide (ITO) that combine optical transparency with electrical conductivity. This composite material approach allows the sensor to maintain visibility through it while providing the necessary capacitive sensing functionality, resolving the conflict between transparency and conductive material availability.
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
Enables portable and efficient contactless eye tracking, capable of detecting eye movements and providing additional sensory data like heartbeat information, enhancing applications such as drowsiness detection and fatigue monitoring.
Implementation Method 1
the sensor being configured to detect movement of the eye based on the electrostatic effect caused by the bulge of the cornea
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
An apparatus (100), comprising a transparent capacitive sensor (102); a body (101) configured to support the transparent capacitive sensor in front of an eye (112) of a user (110); and a driver (106) configured to receive signals from the sensor and to determine eye movements based on the received signals, wherein the sensor (102) is configured to detect movement of the eye (112) based on electrostatic effect caused by a bulge of the cornea of the eye (112). The apparatus may be wearable by the user like eyeglasses.