Eyewear Eye Orientation Sensing Using Spatial Light Gradients

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Solution Overview

Problem

Existing camera-based eye-tracking systems for eyewear are energy-intensive, bulky, and require complex integration, with limited reliability in varying light conditions and causing wearer discomfort.

Innovation Solution

An eyewear system with sensor assemblies sensitive to spatial light gradients, using photodetectors arranged to measure light differences, and a processing unit to assess eye orientation, reducing energy consumption and size while improving reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If camera-based eye-tracking systems are used, then eye orientation determination is achieved, but energy consumption increases

Engineering Contradiction:
Improveeye orientation determinationVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent extracts only the essential information needed for eye orientation determination - the spatial light gradient - while discarding unnecessary data processing requirements of full camera systems. This allows achieving reliable eye tracking with minimal energy consumption by using simple photodetectors instead of complex cameras.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical/optical complex of cameras with a simpler photodetector-based system that directly measures light gradients. This substitution eliminates the energy-intensive image processing while maintaining the core function of eye orientation detection through direct physical measurement of light spatial variations.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If camera-based eye-tracking systems are used, then eye orientation determination is achieved, but device size and weight increase

Engineering Contradiction:
Improveeye orientation determinationVSAvoiddevice weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent extracts only the essential sensing function from the camera system, using minimal photodetector elements that can be integrated directly into the eyewear frame. This extraction eliminates the bulk of camera components while retaining the core capability to determine eye orientation through light gradient measurement.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces bulky camera hardware with lightweight photodetector assemblies that can be easily integrated into eyewear frames. This substitution maintains the functional capability of eye tracking while dramatically reducing the weight and size of the device, making it suitable for wearable applications.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If light sources are integrated in eyewear equipment, then reliability of eye orientation determination is improved, but energy consumption increases

Engineering Contradiction:
Improveeye orientation determinationVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent employs the eye itself as the light source through its natural reflection and backscattering of ambient light. The eye's own optical properties (corneal reflection, scleral light scattering) provide the necessary light patterns for orientation determination, eliminating the need for external light sources and their associated energy consumption.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent uses ambient light as an intermediary that naturally illuminates the eye, which then reflects and backscatters this light in orientation-dependent patterns. This intermediary approach avoids the need for active light emission while maintaining reliable measurement capability through the eye's natural optical interactions with ambient illumination.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If camera-based eye-tracking systems are used, then eye orientation determination is achieved, but location requirements increase

Engineering Contradiction:
Improveeye orientation determinationVSAvoidlocation requirements
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent replaces camera-based systems with photodetector assemblies that can be positioned directly on the eyewear frame at optimal locations for capturing light gradients from the eye. This substitution eliminates the complex location requirements of camera systems while maintaining measurement reliability through direct placement at the most effective sensing positions.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical 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

The system provides reliable eye orientation assessment with reduced energy consumption and discomfort, immune to ambient light variations, and suitable for integration in eyewear.

Implementation Method 1

at least two sensor assemblies arranged in the eyewear equipment so as to receive light reflected or backscattered from a wearer's eye

Methodology Applied
Scientific EffectLight: Light

Implementation Method 2

receive light reflected or backscattered from a wearer's eye

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

each sensor assembly being configured to produce signals corresponding to the light received by this sensor assembly

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentEP4685543A1Eyewear equipment with assessment of an orientation of a wearer's eye
Publication Date: 2026.01.28 ESSILOR INTERNATIONAL(COMPAGNIE GENERALE D OPTIQUE)
  • EP4685543A1 patent drawingFigure 1a~1b
  • EP4685543A1 patent drawingFigure 2a~2c
  • EP4685543A1 patent drawingFigure 2d~2f

AI summary

An eyewear equipment (10) provides reliable assessment of an orientation of a wearer's eye. The eye orientation is inferred from spatial light gradient magnitudes which are provided by sensor assemblies (3) located so as to receive light reflected or backscattered from the wearer's eye. The eyewear equipment comprises a processing unit (14) which may be of neural network type, for assessing the eye orientation from the spatial light gradient magnitudes.