SWIR Eye Tracking for Night Vision Compatibility

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Solution Overview

Problem

Current optical eye tracking systems operating in the near-infrared spectrum interfere with night vision systems, causing blooming and saturation, and pose safety risks due to prolonged exposure to near-infrared light.

Innovation Solution

A short-wave infrared (SWIR) eye tracking system using a SWIR light source and sensitive image sensor operating above 900 nm, compatible with night vision systems, to track eye movements without interference and reduce safety risks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If near-infrared illuminators (800-900 nm) are used for eye tracking, then eye tracking functionality is achieved, but night vision images experience blooming and saturation

Engineering Contradiction:
Improveeye tracking functionalityVSAvoidblooming and saturation in night vision images
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the wavelength parameter of the illuminator from near-infrared (800-900 nm) to short-wave infrared (1000-2000 nm). This parameter change allows the eye tracking system to operate in a wavelength range that does not interfere with night vision sensors, thereby eliminating blooming and saturation while maintaining eye tracking functionality.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If near-infrared light (830-870 nm) is used for extended eye tracking, then continuous eye movement monitoring is achieved, but eye safety risks increase

Engineering Contradiction:
Improvecontinuous eye movement monitoringVSAvoideye safety risks
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the wavelength parameter from near-infrared (830-870 nm) to short-wave infrared (1000-2000 nm). This parameter change enables continuous eye tracking monitoring while reducing eye safety risks, as SWIR light at these wavelengths is less hazardous to the eye compared to near-infrared wavelengths.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If digital night vision operates at 60 Hz with 16 ms dwell time, then night vision imaging is achieved, but timing overlap with eye tracking illumination occurs

Engineering Contradiction:
Improvenight vision imagingVSAvoidtiming overlap between systems
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent changes the wavelength parameter of the illuminator to short-wave infrared (1000-2000 nm), which eliminates interference with night vision sensors. This allows both systems to operate simultaneously without timing trades, as the SWIR illuminator does not saturate the night vision sensor, thereby resolving the timing overlap issue.

Inventive Principle:
Principle #35Parameter changes

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 SWIR eye tracking system effectively tracks eye movements without degrading night vision images and is safer for user's eyes, ensuring compatibility and reducing interference with night vision systems.

Implementation Method 1

A short-wave infrared (SWIR) eye tracking system includes a SWIR light source configured to emit SWIR light above 900 nm

Methodology Applied
Scientific EffectInfrared radiation: Infrared Radiation

Implementation Method 2

a SWIR sensitive image sensor configured to capture images of the environment illuminated by the SWIR light source

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP3812824B1Night vision compatible short-wave infrared eye tracking system
Publication Date: 2026.03.04 ROCKWELL COLLINS INC
  • EP3812824B1 patent drawingFigure 1
  • EP3812824B1 patent drawingFigure 2
  • EP3812824B1 patent drawingFigure 3

AI summary

A system and method. The system may include an eye tracking system. The eye tracking system may include a short-wave infrared (SWIR) light source (302) configured to emit SWIR light at between 900 nanometers (nm) and 1,700 nm wavelength onto an environment, a SWIR sensitive image sensor (304) configured to capture images of the environment illuminated by the SWIR light source, and a processor (306) communicatively coupled to the SWIR sensitive image sensor. The processor may be configured to: receive image data from the SWIR sensitive image sensor; track movement of an eye of a user based on the image data; and output eye tracking system data indicative of the tracked movement of the eye of the user.