Touch-Fingerprint Fusion Sensor for Display Devices

Solution Overview

Problem

Current touch display devices face challenges in improving product reliability while reducing manufacturing costs, as existing touch sensors are often separate components that increase complexity and cost.

Innovation Solution

A touch display device with a touch-fingerprint fusion sensor unit that integrates fingerprint sensors into the touch sensor unit, utilizing a combination of first and second fingerprint sensor electrodes, insulating layers, and touch electrodes to provide both touch and fingerprint sensing functions, thereby eliminating the need for additional fingerprint recognition components and simplifying the device structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a separate fingerprint sensor is added to the touch display device, then fingerprint sensing capability is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:

Improvefingerprint sensing capabilityVSAvoiddevice complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines the fingerprint sensor and touch sensor into a single integrated sensor unit. The fingerprint sensor electrodes are disposed in the same structure as the touch sensor electrodes, with insulating layers separating them. This merging eliminates the need for separate fingerprint recognition components, directly reducing device complexity while maintaining both fingerprint sensing and touch sensing capabilities.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The integrated sensor unit serves multiple functions: it detects both fingerprint patterns through the fingerprint sensor electrodes and detects touch input through the touch sensor electrodes. The same structural framework supports both sensing modalities, making the sensor unit universal and eliminating the need for separate dedicated components for each function.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If a separate fingerprint sensor is added to the touch display device, then fingerprint sensing capability is improved, but manufacturing cost increases

Engineering Contradiction:

Improvefingerprint sensing capabilityVSAvoidmanufacturing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent combines the fingerprint sensor and touch sensor into a single integrated sensor unit. The fingerprint sensor electrodes are disposed in the same structure as the touch sensor electrodes, with insulating layers separating them. This merging eliminates the need for separate fingerprint recognition components, directly reducing device complexity while maintaining both fingerprint sensing and touch sensing capabilities.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The integrated sensor unit serves multiple functions: it detects both fingerprint patterns through the fingerprint sensor electrodes and detects touch input through the touch sensor electrodes. The same structural framework supports both sensing modalities, making the sensor unit universal and eliminating the need for separate dedicated components for each function.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If fingerprint sensor electrodes are disposed in the active area, then fingerprint sensing is enabled, but pixel aperture ratio may deteriorate

Engineering Contradiction:

Improvefingerprint sensing capabilityVSAvoidpixel aperture ratio

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent applies local quality by disposing the fingerprint sensor electrodes specifically in the non-emissive area of the display, rather than uniformly across the entire active area. The insulating layers are configured to electrically isolate the electrodes while allowing light to pass through the emissive areas. This localized arrangement enables fingerprint sensing functionality while preserving the optical performance and aperture ratio of the display pixels.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent resolves the spatial conflict by utilizing the vertical dimension and electrical insulation properties. The insulating layers are disposed between the fingerprint sensor electrodes and the pixel structure, creating electrical isolation while maintaining optical transparency. This allows the fingerprint sensing electrodes to occupy the same planar space as the pixels without interfering with light emission, effectively adding fingerprint sensing capability in a different dimensional layer.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS11416091B2Touch display device

Publication Date: 2022.08.16 LG DISPLAY CO LTD

AI summary

A touch display device includes a display unit including pixels disposed in an active area, an encapsulation unit disposed on the display unit, and a touch-fingerprint fusion sensor unit having a touch sensor function and a fingerprint sensor function in the active area on the encapsulation unit. The touch-fingerprint fusion sensor unit includes first fingerprint sensor electrodes disposed in a fingerprint sensor area on the encapsulation unit, a first touch insulating layer disposed on the first fingerprint sensor electrodes, second fingerprint sensor electrodes disposed in the fingerprint sensor area on the first touch insulating layer, a second touch insulating layer disposed on the second fingerprint sensor electrodes, and a plurality of first and second touch electrodes disposed on the second touch insulating layer. The first fingerprint sensor electrodes, the second fingerprint sensor electrodes, and the first and second touch electrodes overlap the non-emissive area.