Localized Display Illumination for Under-Display Fingerprint Sensing

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Electronic devices with under-display fingerprint sensors face challenges in capturing well-illuminated user inputs due to low light transmissibility, leading to sub-optimal image capturing and potential discomfort from high-intensity light radiation during biometric authentication, especially in dark environments.

Innovation Solution

A biometric authentication system that includes a biometric authentication manager to detect the shape of user input on a touch-sensitive display and adjust the brightness of specific regions to enhance reflection and facilitate authentication, minimizing light leakage and improving user experience.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If high-intensity light is used to illuminate the fingertip for biometric authentication, then the image capturing quality is improved, but user discomfort increases due to light radiation

Engineering Contradiction:

Improveimage capturing qualityVSAvoiduser discomfort from light radiation

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by illuminating only the specific region where the fingertip contacts the display, rather than illuminating the entire display. The biometric authentication manager determines the contact area shape and adjusts brightness only within that localized region, providing sufficient light for image capture while limiting unnecessary light exposure to the user's eyes.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The display is segmented into multiple controllable regions with different brightness levels. The system divides the display into a first region (where the fingertip contacts) and a second region (surrounding area), applying different brightness settings to each segment to optimize both authentication quality and user comfort.

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If the entire display is illuminated for biometric authentication, then the image capturing is sufficient, but power consumption increases

Engineering Contradiction:

Improveimage capturing sufficiencyVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

Instead of illuminating the entire display, the system applies illumination only to the localized contact area where the fingertip rests. The biometric authentication manager calculates the contact area shape from touch input data and configures the display brightness specifically for that region, dramatically reducing the number of illuminated pixels and thus power consumption.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The system applies partial illumination - providing sufficient light only where needed for fingerprint capture rather than illuminating the entire display. This partial action approach achieves the minimum necessary illumination for successful biometric authentication while minimizing energy waste.

Inventive Principle:

Principle #16Partial or excessive action

3Productivity

If the display brightness is increased to improve reflection capture, then the authentication efficiency is improved, but user discomfort from light radiation increases

Engineering Contradiction:

Improveauthentication efficiencyVSAvoiduser discomfort from light radiation

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system increases brightness only in the localized contact region where reflection needs to be captured, rather than increasing overall display brightness. This localized brightness enhancement maintains authentication efficiency by ensuring sufficient reflected light reaches the sensor, while preventing unnecessary light exposure that would cause user discomfort.

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 system enables improved biometric authentication by optimizing illumination based on user input shape, reducing discomfort and power consumption while enhancing authentication efficiency.

Implementation Method 1

a touch-sensitive display configured to detect a shape of user input

Methodology Applied

Scientific EffectCapacitance: Capacitance

Implementation Method 2

receiving the reflection of the fingertip touch input and analyzing, responsive to receiving the reflection, the reflection at the biometric authentication system effective to enable the biometric authentication system to authenticate the user

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentUS12572638B2Spatially-configurable localized illumination for biometric authentication

Publication Date: 2026.03.10 GOOGLE LLC

AI summary

This document describes systems and techniques directed at spatially-configurable localized illumination for biometric authentication systems. In aspects, during biometric authentication, a biometric authentication system having a biometric authentication manager is configured to receive user input at a touch-sensitive display. Responsive to and based on the user input, the biometric authentication manager determines a shape of a contact area of the user input at the touch-sensitive display. Based on the determined shape, the biometric authentication manager alters a brightness of a region of the display to increase a reflection of light from the user input, effective to facilitate biometric authentication.