Flexible Touch Panel Integrating Capacitive Fingerprint Sensor

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Solution Overview

Problem

Conventional display apparatuses face challenges with fingerprint recognition due to the need for a designated space for fingerprint scanners, which reduces available surface area for display and touch control, and the sensitivity of capacitive fingerprint sensors decreases significantly with increased distance from the sensor electrodes, leading to poor fingerprint pattern recognition and resolution.

Innovation Solution

A flexible display panel integrating a flexible touch panel with a capacitive fingerprint sensor and a flexible display module, where the fingerprint sensor is embedded in the touch panel on a thin flexible cover glass, allowing for sensitive and accurate fingerprint recognition without a dedicated button and enabling a virtual fingerprint scanner, and using a time-division driving mode for touch and fingerprint sensing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a designated space for fingerprint scanner is provided, then fingerprint recognition function is achieved, but available surface area for display and touch control is reduced

Engineering Contradiction:

Improvefingerprint recognition functionVSAvoidavailable surface area for display

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent merges the fingerprint sensor with the touch panel by integrating capacitive sensing electrodes into the touch panel structure. The touch panel serves dual functions: touch control and fingerprint recognition, eliminating the need for a separate dedicated button or scanner area.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The touch panel is designed to perform multiple functions simultaneously - it acts as both a touch control interface and a fingerprint sensor. The same panel structure and electrode system are used for both touch detection and fingerprint pattern recognition, maximizing space utilization.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Area of stationary object

If distance between finger and sensor electrodes is increased, then display area is expanded, but sensitivity and resolution of fingerprint recognition deteriorates

Engineering Contradiction:

Improvedisplay areaVSAvoidfingerprint pattern recognition resolution

Core Design Contradiction:

Area of stationary objectVSMeasurement precision

Solution Approach 1:

By merging the fingerprint sensor with the touch panel, the patent eliminates the air gap between the finger and sensing electrodes that would exist with a separate scanner. The finger contacts the touch panel directly, ensuring minimal distance for optimal capacitive coupling and signal strength.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The use of a thin flexible cover glass in the touch panel allows the sensing electrodes to be positioned very close to the finger surface while maintaining flexibility and display area. The thin film structure minimizes the distance barrier for capacitive sensing.

Inventive Principle:

Principle #30Flexible shells and thin films

3Adaptability or versatility

If separate fingerprint scanner is used, then dedicated scanning function is achieved, but device complexity and manufacturing process are increased

Engineering Contradiction:

Improvededicated scanning functionVSAvoiddevice structure complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple sensing functions into a single integrated structure. The touch panel incorporates both touch control electrodes and fingerprint sensing electrodes, reducing the number of separate components and simplifying the overall device architecture.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The integrated touch panel serves multiple purposes - touch control, display protection, and fingerprint sensing - eliminating the need for separate dedicated scanner components and reducing device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 design allows for sensitive and accurate fingerprint recognition with minimal surface area usage, enabling a virtual fingerprint scanner and maintaining display and touch functionality without sacrificing valuable space, while improving sensitivity and resolution by reducing the distance between the finger and sensor electrodes.

Implementation Method 1

a capacitive fingerprint sensor comprising an array of capacitive sensing electrodes configured to enable identification of a fingerprint of a finger

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS10452888B2Flexible touch panel, flexible display panel and flexible display apparatus, and fabricating method thereof

Publication Date: 2019.10.22 BOE TECHNOLOGY GROUP CO LTD

AI summary

The present application discloses a flexible display panel having a flexible touch panel and a flexible display module laminated together with the flexible touch panel. The flexible touch panel includes a touch sensor having a plurality of touch electrodes configured to detect a touch, and a capacitive fingerprint sensor having an array of capacitive sensing electrodes configured to enable identification of a fingerprint of a finger.