Structured Light Demodulation for Ambient Light Suppression

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing skin measurement systems struggle with ambient light interference in uncontrolled environments, leading to inaccurate skin analysis and potential privacy concerns due to non-discriminatory imaging.

Innovation Solution

A system comprising an image projection unit that projects a time-varying spatially modulated pattern, an imaging unit to capture multiple images, and a processing unit to demodulate these images, selectively suppressing ambient light and generating an ambient light-suppressed image based on a target section.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If conventional display devices are used in bright ambient light conditions, then the display remains visible, but the contrast ratio deteriorates and viewing quality deteriorates

Engineering Contradiction:
Improveambient light suppressionVSAvoidviewing quality
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The backlight is divided into multiple independently controllable light emitting regions (first, second, third light emitting regions) that can be selectively dimmed or turned off based on ambient light conditions and content requirements, allowing selective suppression of ambient light interference while maintaining necessary visibility

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The display device dynamically adjusts the luminance parameters of different backlight regions based on detected ambient light intensity, changing the brightness parameters of light emitting regions to optimize contrast ratio and viewing quality under varying ambient light conditions

Inventive Principle:
Principle #35Parameter changes

2Illumination intensity

If the entire backlight is dimmed to suppress ambient light, then ambient light suppression improves, but visibility of important content deteriorates

Engineering Contradiction:
Improveambient light suppressionVSAvoidcontent visibility
Core Design Contradiction:
Illumination intensityVSLoss of information

Solution Approach 1:

Different regions of the backlight are assigned different luminance characteristics - some regions are dimmed or turned off to suppress ambient light, while other regions maintain or increase brightness to ensure important content remains visible, creating local quality variations across the display

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The backlight is segmented into multiple independently controllable regions that can be selectively adjusted, allowing the system to suppress ambient light in certain areas while maintaining visibility of important content in other areas through independent luminance control

Inventive Principle:
Principle #1Segmentation

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

Effectively suppresses ambient light interference, enhances skin analysis accuracy, and maintains user privacy by selectively projecting and demodulating images to exclude background elements.

Implementation Method 1

determining ambient light conditions using an ambient light sensor

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Implementation Method 2

controlling luminance of light emitting regions in the backlight

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP4150522B1Ambient light suppression
Publication Date: 2026.05.06 KONINKLIJKE PHILIPS NV
  • EP4150522B1 patent drawingFigure 1
  • EP4150522B1 patent drawingFigure 2~3
  • EP4150522B1 patent drawingFigure 4

AI summary

According to an aspect, there is provided a system (200) comprising: an image projection unit (210) configured to project an illumination pattern onto at least a portion of a scene, an imaging unit (220) configured to capture a plurality of images of the scene while the illumination pattern is projected onto the scene, and a processing unit (230) configured to: demodulate the plurality of images based on the illumination pattern and with respect to a target section in the plurality of captured images, wherein the target section corresponds to one of: a portion of the scene on which the illumination pattern is selectively projected while the plurality of images were captured, a portion of the scene at which the projected illumination pattern is resolvable, a portion of the scene with pixel depth values which satisfy a predetermined range; and generate an ambient light supressed image of the scene based on results of the demodulation.