Ultrasonic Touch Panel Layout for Faster Fingerprint Identification

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Solution Overview

Problem

Existing touch panel technologies face challenges in integrating ultrasonic fingerprint identification with display devices, particularly in achieving high integration, accurate fingerprint identification, and reducing identification time.

Innovation Solution

A touch panel design that integrates ultrasonic fingerprint identification and mutual capacitive touch detection, utilizing a stacked structure with a first electrode, circuit structure, and piezoelectric layer, where the first electrode includes sub-electrode strips and the circuit structure includes detection electrodes, allowing for shared ultrasonic excitation and detection portions to enhance accuracy and reduce identification time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If ultrasonic fingerprint identification structure is integrated into touch panel, then fingerprint identification capability is added, but device complexity increases

Engineering Contradiction:

Improvefingerprint identification capabilityVSAvoidstructure complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines ultrasonic fingerprint identification structure with touch panel structure by integrating driving electrode, receiving electrode, and piezoelectric layer into the existing touch panel layers, achieving multi-functionality without separate structures

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The touch panel structure serves dual purposes: touch detection and ultrasonic fingerprint identification, with the piezoelectric layer and electrode structures performing both touch sensing and ultrasonic wave generation/detection functions

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Measurement precision

If separate touch detection and fingerprint identification structures are used, then each function can be optimized, but identification time increases

Engineering Contradiction:

Improvefingerprint identification accuracyVSAvoididentification time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent merges touch detection and fingerprint identification into a single integrated structure where the piezoelectric layer and electrode arrangements serve both functions simultaneously, enabling concurrent operation and reducing total identification time

Inventive Principle:

Principle #5Merging (Combining)

3Measurement precision

If full ultrasonic coverage is provided for fingerprint identification, then identification accuracy is improved, but energy consumption increases

Engineering Contradiction:

Improvefingerprint identification accuracyVSAvoidenergy consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent divides the ultrasonic excitation into segmented operations where different electrode regions are activated sequentially or selectively based on touch detection results, providing ultrasonic coverage only where needed rather than uniformly across the entire panel

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

The design enables simultaneous touch detection and fingerprint identification with improved accuracy and reduced identification time by reusing ultrasonic excitation and detection portions, enhancing the integration of fingerprint identification capabilities in display devices.

Implementation Method 1

the piezoelectric layer is excited by the driving voltage to generate an inverse piezoelectric effect and emit a first ultrasonic wave outward

Methodology Applied

Scientific EffectInverse piezoelectric effect: Piezoelectric Effect

Implementation Method 2

the piezoelectric layer converts the second ultrasonic wave into a voltage signal, which is transmitted to the fingerprint identification module

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP3933663B1Touch panel and driving method therefor, and display device

Publication Date: 2026.04.01 BOE TECHNOLOGY GROUP CO LTD

Figure 1A~2A
Figure 2B~2C
Figure 2D~2E

AI summary

A touch panel, a driving method thereof, and a display device are disclosed. The touch panel includes a touch detection structure and a fingerprint identification structure; the touch panel includes a first electrode, a circuit structure, and a piezoelectric layer which are stacked. In a plane parallel to a main surface of the piezoelectric layer, the first electrode includes a plurality of first sub-electrode strips arranged in a first direction and extending in a second direction, and the circuit structure includes a plurality of circuit sub-structures arranged in an array in the first direction and the second direction, each of the circuit sub-structures includes a detection electrode; in the first direction, an orthographic projection of each of the first sub-electrode strips on a main surface of the piezoelectric layer covers orthographic projections of detection electrodes of at least two circuit sub-structures on the main surface of the piezoelectric layer. The touch panel provided by the embodiments of the present disclosure can achieve touch detection and fingerprint identification by using ultrasonic waves; besides, after the touch region is judged by touch detection, fingerprint identification can be performed on the touch region to improve identification accuracy and reduce identification time.