Shadow Mask Eye Tracker for Compact Coded Aperture Gaze Sensing

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Solution Overview

Problem

Existing eye trackers face challenges in achieving accurate eye movement detection and user authentication while maintaining a compact and cost-effective design, particularly in applications like augmented and virtual reality devices.

Innovation Solution

An eye tracker comprising a shadow mask with specific pixel and transparent portion configurations, coupled with a detection region and light emitting elements, enables precise eye movement detection and user authentication without bulky optics, using coded aperture imaging for compact and efficient operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a gaze estimator is provided in the lens to enable communication with the outside world, then the child's social interaction capability is improved, but the risk of infection from external viruses is increased

Engineering Contradiction:
Improvesocial interaction capabilityVSAvoidinfection risk
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

A gaze estimator is provided inside the lens to estimate the gaze direction of the wearing person. This intermediary device enables communication between the isolated eye and the outside world by translating eye movements into observable signals (such as LED indicators or digital displays), allowing social interaction without direct exposure to external pathogens.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The gaze estimator is nested within the contact lens structure itself, with the estimator positioned in the lens body and the indicator positioned on the inner surface of the lens. This nested configuration allows the communication function to be integrated into the isolation barrier, maintaining the sealed environment while enabling external interaction.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Object-affected harmful factors

If the lens is completely sealed to prevent virus entry, then infection protection is improved, but the ability to communicate with the outside world deteriorates

Engineering Contradiction:
Improveinfection protectionVSAvoidcommunication capability
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The gaze estimator acts as an intermediary that bridges the sealed lens environment and the external world. It receives input from the eye (gaze direction) and produces output visible to others (indicators), enabling communication without compromising the sealed structure that provides infection protection.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces direct mechanical/optical communication (such as opening the lens or using transparent sections) with an electronic/optical signaling system. The gaze estimator uses LEDs or digital displays to convey eye movement information, substituting a complex sealed communication mechanism with a simpler electronic signaling approach that maintains both sealing and communication capabilities.

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

Data Source

PatentEP4599317B1Eye tracker comprising a shadow mask and electronic device
Publication Date: 2026.05.06 AMS INTERNATIONAL AG
  • EP4599317B1 patent drawingFigure 1
  • EP4599317B1 patent drawingFigure 2A~2B
  • EP4599317B1 patent drawingFigure 2C

AI summary

An eye tracker (11) comprises a shadow mask (100), a light emitting element (116), and a detection region (110) arranged at a first side of the shadow mask (100). The light emitting element (116) is configured to emit electromagnetic radiation (16) towards an eye (107) arranged at a second side of the shadow mask (100), the shadow mask (100) comprising transparent portions (102) being transparent for the electromagnetic radiation (16) and opaque portions (101) being opaque for the electromagnetic radiation (16), the transparent portions (102) having a maximum width measured in a first horizontal direction. The detection region (110) is configured to receive electromagnetic radiation (16) emitted by the light emitting element (116), reflected by a cornea (108) of the eye (107) and transmitted by the shadow mask (100), the detection region (110) comprising a pixel array comprising a plurality of pixels (111). A maximum distance PS between adjacent pixels and the maximum width wA of the transparent portions satisfy the following formula: 0.9 * wA ≤ PS ≤ 1.25 * wA, the maximum distance between adjacent pixels being measured in the first horizontal direction.