Single Image Sensor RGB IR Separation for Compact Biometric Devices

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Solution Overview

Problem

The integration of infrared imaging capabilities into electronic devices increases their size, and existing camera systems that use one image sensor for both visible and infrared light often suffer from degraded RGB image quality due to infrared components mixing with visible light data.

Innovation Solution

An electronic device with a pixel array including R, G, B, and IR subpixels, and a color filter array that allows for the separation and correction of infrared components from raw image data, enabling the generation of high-quality RGB and IR images using a single image sensor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If an infrared camera is mounted on the electronic device to obtain infrared images, then infrared imaging capability is improved, but the size of the electronic device increases

Engineering Contradiction:
Improveinfrared imaging capabilityVSAvoiddevice size
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent combines infrared and visible light imaging functions into a single image sensor. The image sensor includes both infrared-sensitive pixels and visible light-sensitive pixels with color filters, allowing simultaneous acquisition of infrared and RGB images without requiring separate camera modules, thereby reducing device size while maintaining dual imaging capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The image sensor is designed to perform multiple functions: it can capture visible light images with color information through RGB filters and capture infrared images through infrared-pass filters. This multi-functional sensor eliminates the need for separate dedicated infrared camera hardware, achieving compact integration of both imaging modes.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Volume of moving object

If an infrared cut-off filter is removed to reduce device size, then device size is reduced, but infrared components mix with visible light data degrading RGB image quality

Engineering Contradiction:
Improvedevice sizeVSAvoidRGB image quality
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The image sensor is segmented into different pixel types: some pixels are equipped with RGB color filters for visible light imaging, while other pixels are equipped with infrared-pass filters for infrared imaging. This spatial segmentation allows each pixel to selectively respond to specific wavelength ranges, preventing infrared contamination in RGB images while maintaining compact sensor structure without requiring an infrared cut-off filter.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the image sensor have different optical filtering properties. Specifically, certain pixels have infrared-blocking color filters while others have infrared-pass filters. This local differentiation of optical properties allows the sensor to simultaneously capture both visible and infrared light without cross-contamination, eliminating the need for a global infrared cut-off filter and maintaining high RGB image quality.

Inventive Principle:
Principle #3Local quality

3Volume of moving object

If one image sensor is used for both visible and infrared light, then device size is reduced, but infrared components contaminate RGB images

Engineering Contradiction:
Improvedevice sizeVSAvoidRGB image purity
Core Design Contradiction:
Volume of moving objectVSLoss of information

Solution Approach 1:

The image sensor is divided into multiple pixel types with different filtering characteristics. Some pixels use RGB color filters that block infrared light, while other pixels use infrared-pass filters. This segmentation ensures that infrared light only reaches designated infrared-sensitive pixels, preventing infrared contamination in the RGB image data while maintaining compact sensor design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different pixels within the same sensor array have locally optimized optical filtering properties. Pixels intended for visible light imaging have infrared-blocking filters, while pixels intended for infrared imaging have infrared-pass filters. This local optimization of filter properties at the pixel level ensures clean separation of spectral information without requiring additional infrared cut-off filters, preserving RGB image purity while enabling compact integration.

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

This approach allows for efficient removal of infrared components from RGB images and enables biometric authentication using IR images while displaying RGB images, effectively reducing device size and maintaining image quality.

Implementation Method 1

In the photoelectric conversion element, the movement of electric charges, that is, a current, occurs according to the photoelectric effect. The image data may be generated by converting the current into a digital signal.

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP3675477B1Electronic device for providing function by using RGB image and IR image acquired through one image sensor
Publication Date: 2023.03.15 SAMSUNG ELECTRONICS CO LTD
  • EP3675477B1 patent drawingFigure 1
  • EP3675477B1 patent drawingFigure 2
  • EP3675477B1 patent drawingFigure 3

AI summary

An electronic device is disclosed. The electronic device may comprise: an image sensor for acquiring raw image data corresponding to light of infrared band and visible light band, with respect to an external object; and a processor, wherein the processor is configured to: receive a request for acquiring the raw image data corresponding to the external object; on the basis of the request configured to be performed using a first function of the image sensor, generate an RGB image related to the external object by using first raw image data corresponding to the light of visible light band, obtained through the image sensor, and on the basis of the request configured to be performed using a second function of the image sensor, perform biometric authentication related to the external object by using second raw image data corresponding to the light of infrared band, obtained through the image sensor. In addition, various embodiments recognized through the specification are possible.