Fingerprint Sensing via Selective Display Sub-Pixel Activation

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Solution Overview

Problem

Current fingerprint recognition systems in electronic devices face interference from stray light, leading to poor recognition accuracy due to the reception of light from different pixels, which affects the effectiveness of fingerprint identification.

Innovation Solution

The electronic device employs a display unit with green, blue, and red sub-pixels, where the display unit produces visible light of a specific wavelength range, primarily green light, to minimize stray light interference by only activating the green sub-pixel during fingerprint recognition, while the blue and red sub-pixels are off, and incorporates photoelectric converting elements in the sensing unit to enhance sensing accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If all sub-pixels are activated during fingerprint recognition, then the sensing coverage is improved, but stray light interference increases

Engineering Contradiction:

Improvesensing coverageVSAvoidstray light interference

Core Design Contradiction:

Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent divides the display unit into multiple sub-pixels (red, green, blue) and selectively activates only specific sub-pixels during fingerprint recognition. By segmenting the light source activation, the system achieves adequate sensing coverage while minimizing stray light interference from non-activated sub-pixels.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by using sub-pixels with different light wavelengths (colors) for different purposes. Specifically, it activates only certain wavelength ranges (e.g., green and blue sub-pixels) that provide good fingerprint contrast while avoiding other wavelengths that cause excessive stray light, thus optimizing local light properties for the specific sensing task.

Inventive Principle:

Principle #3Local quality

2Illumination intensity

If multiple sub-pixels are activated during fingerprint recognition, then the light intensity is improved, but power consumption increases

Engineering Contradiction:

Improvelight intensityVSAvoidpower consumption

Core Design Contradiction:

Illumination intensityVSUse of energy by moving object

Solution Approach 1:

The patent applies partial action by activating only a subset of sub-pixels (e.g., green and blue) rather than all sub-pixels during fingerprint recognition. This partial activation provides sufficient light intensity for accurate fingerprint sensing while significantly reducing power consumption compared to full-display activation.

Inventive Principle:

Principle #16Partial or excessive action

3Speed

If all sub-pixels are activated during fingerprint recognition, then the recognition speed is improved, but recognition accuracy deteriorates

Engineering Contradiction:

Improverecognition speedVSAvoidrecognition accuracy

Core Design Contradiction:

SpeedVSMeasurement precision

Solution Approach 1:

The patent changes the wavelength parameter of the light source by selectively activating specific sub-pixels with different colors. By using specific wavelength combinations (e.g., green and blue) that provide optimal contrast for fingerprint patterns, the system achieves both fast recognition speed and high accuracy, avoiding the stray light interference that would occur with all sub-pixels activated.

Inventive Principle:

Principle #35Parameter changes

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 improves fingerprint recognition accuracy by reducing stray light interference and optimizing power consumption, as only necessary sub-pixels are activated during fingerprint recognition, resulting in enhanced sensing effectiveness and improved recognition accuracy.

Implementation Method 1

The display unit includes a green sub-pixel, a blue sub-pixel and a red sub-pixel... producing a visible light by the display unit

Methodology Applied

Scientific EffectLight emission from sub-pixels: Light Emitting Diode

Implementation Method 2

using the sensing unit to sense a reflected portion of the visible light... The plurality of photoelectric converting elements are respectively disposed in one sub-pixel

Methodology Applied

Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentUS11367300B2Method for enabling electronic device to receive fingerprint data and electronic device thereof

Publication Date: 2022.06.21 INNOLUX CORP

AI summary

A method for enabling an electronic device to receive a fingerprint data and an electronic device are disclosed. The electronic device includes a display unit and a sensing unit, and the display unit includes a green sub-pixel, a blue sub-pixel and a red sub-pixel. The method includes the following steps: the green sub-pixel of the display unit being in an on state, the blue sub-pixel and the red sub-pixel of the display unit being in off state; producing a visible light by the display unit; using the sensing unit to sense a reflected portion of the visible light; and receiving the fingerprint data from the sensing unit.