Integrated Capacitive Sensing Device for Touch and Fingerprint Recognition

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Solution Overview

Problem

Current technologies require separate sensing units and control circuits for touch control and fingerprint recognition on portable and flat display devices, leading to increased complexity and costs.

Innovation Solution

A capacitive sensing device with a substrate featuring a touch sensing electrode group and a fingerprint sensing electrode group, both integrated with a capacitive sensing integrated circuit, allowing for simultaneous touch control and fingerprint pattern sensing using a shared circuit, with varying electrode distribution densities and configurations to optimize sensing capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate sensing units and control circuits are used for touch control and fingerprint recognition, then each function can be independently optimized, but device complexity and manufacturing costs increase

Engineering Contradiction:

Improvesensing function reliabilityVSAvoidnumber of sensing units and control circuits

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines touch control sensing and fingerprint recognition sensing into a single capacitive sensing device with one control circuit. The control circuit integrates multiple sensing functions that were previously separated, reducing device complexity while maintaining reliable sensing through unified capacitive measurement of different electrode groups

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The control circuit is designed to perform multiple functions: it can sense capacitance changes in both the touch sensing electrode group and the fingerprint sensing electrode group, enabling both touch control and fingerprint recognition with a single universal circuit rather than separate dedicated circuits for each function

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Manufacturing precision

If separate sensing units are used for touch control and fingerprint recognition, then each sensing function can be independently optimized, but manufacturing costs increase

Engineering Contradiction:

Improvesensing function optimizationVSAvoidmanufacturing cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent merges touch control and fingerprint recognition into a single integrated sensing device with shared substrate, electrode structures, and control circuitry. This consolidation reduces manufacturing steps and material requirements compared to producing separate sensing units, thereby lowering manufacturing costs while maintaining the ability to independently optimize each sensing function through dedicated electrode groups

Inventive Principle:

Principle #5Merging (Combining)

3Device complexity

If a shared capacitive sensing circuit is used for both touch control and fingerprint sensing, then device complexity and manufacturing costs are reduced, but sensing accuracy may be compromised

Engineering Contradiction:

Improvenumber of sensing circuitsVSAvoidcapacitance sensing accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent segments the capacitive sensing device into distinct electrode groups: a touch sensing electrode group and a fingerprint sensing electrode group. Each group is independently configured with specific electrode distributions optimized for its particular sensing function, allowing the shared control circuit to accurately measure capacitance changes for different purposes without cross-interference

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by creating different electrode distribution densities in different regions: the fingerprint sensing electrode group has a higher electrode distribution density optimized for fingerprint pattern detection, while the touch sensing electrode group has a different distribution optimized for touch position detection. This localized optimization maintains measurement precision for each function despite using a shared control circuit

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 solution reduces manufacturing steps and costs while enhancing sensing accuracy and user experience by integrating touch and fingerprint sensing functions within a single capacitive sensing device, improving recognition rates and reducing noise interference.

Implementation Method 1

sensing a capacitance change in the touch sensing electrode group to generate a touch control instruction

Methodology Applied

Scientific EffectCapacitance: Capacitance

Implementation Method 2

sensing a capacitance change in the fingerprint sensing electrode group to generate a fingerprint pattern

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS10268863B2Capacitive sensing device, fingerprint sensing device and method for manufacturing capacitive sensing device

Publication Date: 2019.04.23 ILI TECHNOLOGY CORPORATION

AI summary

A capacitive sensing device includes: a substrate; a touch sensing electrode group, disposed above the substrate; a fingerprint sensing electrode group, disposed above the substrate; and a capacitive sensing integrated circuit, electrically connected to the touch sensing electrode group and the fingerprint sensing electrode group, sensing a capacitance change in the touch sensing electrode group to generate a touch control instruction, and sensing a capacitance change in the fingerprint sensing electrode group to generate a fingerprint pattern.