Time-Division Fill-Light Imaging for Bright, True-Color Frames

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing imaging technologies struggle to achieve true color information and appropriate brightness in low-illuminance environments without causing interference to the photographed object.

Innovation Solution

A time division multiplexing method that alternately generates visible light frames and fill light frames using the same image sensor, combining them to create a composite frame that retains color information from visible light frames and brightness from fill light frames.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If visible light fill light device is used to increase light amount, then image brightness is improved, but interference to photographed object occurs causing overexposure and distortion

Engineering Contradiction:
Improveimage brightnessVSAvoidinterference to photographed object
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent applies periodic action by alternately switching between visible light imaging mode and fill light imaging mode in a time-division multiplexing manner. The visible light fill light device operates periodically rather than continuously, illuminating the scene only during designated fill light frames. This periodic operation provides necessary light for imaging while minimizing interference to the photographed object, as the illumination is activated only when needed for specific frames rather than continuously affecting the scene.

Inventive Principle:
Principle #19Periodic action

2Illumination intensity

If infrared imaging is used to obtain sufficient image brightness, then image brightness is improved, but true color information of the object cannot be obtained

Engineering Contradiction:
Improveimage brightnessVSAvoidtrue color information
Core Design Contradiction:
Illumination intensityVSLoss of information

Solution Approach 1:

The patent merges the advantages of both visible light imaging and infrared fill light imaging by combining images captured in both modes. The processing unit integrates the color information from visible light frames with the brightness information from fill light frames (which may include infrared illumination), producing a composite image that contains both true color information and sufficient brightness. This merging approach allows the system to overcome the limitation of infrared imaging alone by incorporating color data from visible light captures.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If multiple image sensors are used to capture visible light and infrared components separately, then imaging quality is improved, but device complexity increases

Engineering Contradiction:
Improveimaging qualityVSAvoiddevice structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the imaging process into distinct time segments rather than using multiple simultaneous sensors. Instead of capturing visible light and infrared components at the same time with separate sensors, the system alternates between visible light imaging mode and fill light imaging mode in time-division multiplexing fashion. This temporal segmentation allows a single image sensor to effectively perform the function of multiple sensors would provide, reducing device complexity while maintaining imaging quality through sequential capture and computational merging of different light components.

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

This approach effectively enhances image brightness while preserving color information, simplifying the imaging light path and device structure, and maintaining output frame rates in low-illuminance conditions.

Implementation Method 1

the first photoelectrical conversion device generates first image data by photoelectrically converting a visible light component transmitted from a subject, and wherein the second photoelectrical conversion device generates second image data by photoelectrically converting an infrared light component transmitted from the subject

Methodology Applied
Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentEP3820140B1Time-division-multiplexing-based light-supplementing imaging apparatus and method
Publication Date: 2025.07.16 HUAWEI TECH CO LTD
  • EP3820140B1 patent drawingFigure 1
  • EP3820140B1 patent drawingFigure 2a~2b
  • EP3820140B1 patent drawingFigure 3

AI summary

This application provides a time division multiplexing fill light imaging method and device. The method includes: alternately generating a visible light frame and a fill light frame by using an image sensor, where the visible light frame is an image frame generated when the image sensor receives visible light but does not receive fill light, and the fill light frame is an image frame generated when the image sensor receives fill light; and combining a visible light frame and a fill light frame that are adjacent or consecutive, to obtain a composite frame.