HMD Luminance Profile Adjustment via Spatial Lighting Segmentation

Solution Overview

Problem

Conventional head-mounted displays (HMDs) fail to optimize image luminance levels for varying lighting conditions within an environment, leading to impaired visibility for users due to uniform luminance adjustments based on a single photodetector measurement, which does not account for different lighting conditions present in real-world scenarios.

Innovation Solution

A method and system that determine the user's field of view and adjust the luminance profile of images displayed on an HMD based on multiple lighting conditions within that field of view, using a head-tracking system and luminance sensors to generate an optimized luminance profile that reconciles image visibility with environmental lighting, potentially sacrificing grey shades to adjust luminance levels for distinct lighting conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single photodetector measurement is used to adjust luminance levels, then the system complexity is reduced, but the image visibility is impaired due to inability to account for different lighting conditions

Engineering Contradiction:

Improvesystem complexityVSAvoidimage visibility

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent divides the environment into multiple regions with different lighting conditions and uses separate photodetectors for each region. This segmentation allows the system to measure and adjust luminance levels for each specific lighting condition independently, improving image visibility without requiring a single complex measurement system

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different luminance adjustment levels to different regions of the displayed image based on the local lighting conditions detected by photodetectors positioned in specific locations. Each region receives optimized luminance settings tailored to its lighting environment, ensuring optimal visibility across diverse lighting conditions

Inventive Principle:

Principle #3Local quality

2Reliability

If multiple photodetectors are used to measure different lighting conditions, then the image visibility is improved, but the device complexity increases

Engineering Contradiction:

Improveimage visibilityVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the environment into multiple regions with different lighting conditions and uses separate photodetectors for each region. This segmentation allows the system to measure and adjust luminance levels for each specific lighting condition independently, improving image visibility without requiring a single complex measurement system

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs a control system that universally processes signals from multiple photodetectors and applies appropriate luminance adjustments across different image regions. This multi-functional control system manages the complexity by providing a unified approach to handling multiple lighting conditions through a single control architecture

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Device complexity

If uniform luminance adjustment is applied based on single measurement, then the device complexity is minimized, but the adaptability to different lighting conditions deteriorates

Engineering Contradiction:

Improvedevice complexityVSAvoidadaptability to lighting conditions

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent divides the environment into multiple regions with different lighting conditions and uses separate photodetectors for each region. This segmentation allows the system to measure and adjust luminance levels for each specific lighting condition independently, improving image visibility without requiring a single complex measurement system

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different luminance adjustment levels to different regions of the displayed image based on the local lighting conditions detected by photodetectors positioned in specific locations. Each region receives optimized luminance settings tailored to its lighting environment, ensuring optimal visibility across diverse lighting conditions

Inventive Principle:

Principle #3Local quality

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 solution ensures that images are visible and harmonized with the environment by dynamically adjusting luminance levels, reducing contrast ratio variations and minimizing optical artefacts, thereby enhancing user vision in diverse lighting conditions.

Implementation Method 1

conventional HMDs incorporate a photodetector, photodiode or other sensor configured to measure the instantaneous luminance level

Methodology Applied

Scientific EffectPhotodetection: Photoelectric Effect

Data Source

PatentUS11500210B2Method and system for adjusting luminance profiles in head-mounted displays

Publication Date: 2022.11.15 BAE SYSTEMS PLC

AI summary

A method is provided for adjusting a luminance profile of an image displayed on a look-through display to a user. The method comprises: determining a field of view of the user based on a spatial configuration of the user's head. Determining one or more lighting conditions in the field of view. Adjusting the luminance profile for the image based on the field of view, wherein, as a result of the adjusted luminance profile, the image is reconciled with the field of view.