Headworn Display Contrast Control for High Dynamic Range Scenes

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Solution Overview

Problem

Head-worn displays face challenges in maintaining effective contrast and readability of symbology under varying ambient light conditions, leading to reduced visibility and potential distraction for users.

Innovation Solution

An augmented reality system that includes a light sensor, tracker processing unit, and adjustable visor to dynamically adjust symbology intensity and visibility based on ambient light conditions, ensuring clear visibility of critical cockpit instruments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the displayed symbology intensity is increased to improve visibility in high ambient light conditions, then the symbology becomes washed out and difficult to perceive, but if the intensity is decreased for comfort in low light conditions, then the symbology becomes overtly contrasted and blurry

Engineering Contradiction:
Improvesymbology intensityVSAvoidsymbology readability
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The system dynamically adjusts the intensity and contrast of displayed symbology in real-time based on detected ambient light conditions. The controller continuously monitors ambient light levels and modifies display parameters accordingly, transitioning from static to dynamic operation to maintain optimal readability across varying lighting environments.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system employs a feedback mechanism where ambient light sensors detect current lighting conditions and provide this information to the controller, which then adjusts the display output accordingly. This closed-loop control ensures the symbology intensity and contrast are continuously optimized based on actual environmental conditions.

Inventive Principle:
Principle #23Feedback

2Device complexity

If a fixed intensity display is used to simplify the system, then the device complexity is reduced, but the symbology readability varies significantly under changing ambient light conditions

Engineering Contradiction:
Improvedisplay control system complexityVSAvoidsymbology readability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The display system automatically adjusts its own output parameters based on ambient light detection without requiring manual intervention. The controller self-regulates the symbology intensity and contrast by processing sensor data and modifying display settings autonomously, enabling the system to serve itself in maintaining optimal readability.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system changes display parameters (intensity, contrast) in response to varying ambient light conditions. By dynamically modifying these parameters based on sensor feedback, the system maintains consistent symbology readability across different lighting environments without requiring complex manual control mechanisms.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the symbology is made more prominent to ensure visibility, then the readability improves in some conditions, but the symbology may block critical cockpit views

Engineering Contradiction:
Improvesymbology visibilityVSAvoidobstruction of cockpit view
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system applies different display characteristics to different regions or contexts. By adjusting symbology properties locally based on detected ambient light conditions and potentially eye-tracking data, the system optimizes visibility where needed while minimizing obstruction effects in other areas, creating spatially varying display quality.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The symbology display characteristics are dynamically adjusted based on real-time conditions including ambient light levels and potentially gaze direction. This dynamic adaptation allows the system to reduce symbology prominence when it would block critical views while enhancing it when visibility is the primary concern, transitioning between states based on operational context.

Inventive Principle:
Principle #15Dynamics

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

Enhances readability of symbology by adjusting contrast and intensity in real-time, preventing symbology from obstructing critical cockpit views, and maintaining clear visibility across changing light levels.

Implementation Method 1

a light sensor configured to quantify an amount of ambient light passing through, or adjacent to, the display element

Methodology Applied
Scientific EffectLight detection: Photoelectric Effect

Implementation Method 2

an optical relay operatively coupled to the image source and the display element and configured to project the image onto the display element

Methodology Applied
Scientific EffectOptical projection: Reflection

Data Source

PatentEP4343406B1Method for creating uniform contrast on a headworn display against high dynamic range scene
Publication Date: 2026.04.15 ROCKWELL COLLINS INC
  • EP4343406B1 patent drawingFigure 1
  • EP4343406B1 patent drawingFigure 2
  • EP4343406B1 patent drawingFigure 3A

AI summary

An augmented reality system is disclosed that includes an image source (108) configured to generate an image, and a display element (104) configured to display the image. The system further includes an optical relay (112) configured to project the image onto the display element (104). The system further includes a light sensor (120) configured to quantify an amount of ambient light passing through, the display element (104). The system further includes a tracker processing unit (124) operatively coupled to the light sensor (120), the image source (108), and the optical relay (112). The tracker processing unit (124) includes a processor, and a memory configured to store instructions executable by the processors. The processors are instructed to receive sensor data from the light sensor (120), receive the image from the image source (108), update a pixel characteristic for one or more pixels of the image based on the sensor data, and transmit an updated image to the optical relay (112).