Blackened Touch Sensor Layers for Display Visibility

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Solution Overview

Problem

Conventional touchscreens with opaque electrodes reflect external light, reducing visibility and increasing contact resistance between touch pads and driver integrated circuits.

Innovation Solution

A display device with a multilayer structure featuring a blackened layer to prevent light reflection and a partially transparent conductive layer to lower sheet resistance, improving visibility and reducing contact resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If opaque electrodes are used in the touchscreen, then the touch sensor structure is simple and conductive, but external light is reflected reducing visibility

Engineering Contradiction:

Improvetouch sensor structureVSAvoidvisibility

Core Design Contradiction:

Ease of manufactureVSIllumination intensity

Solution Approach 1:

The patent uses a composite structure combining an opaque conductive layer with a blackened layer. The opaque conductive layer provides electrical conductivity and touch sensing function, while the blackened layer (with black matrix material) absorbs external light to prevent reflection. This composite approach maintains the simplicity and conductivity of opaque electrodes while eliminating the light reflection problem that reduces visibility.

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If opaque conductive layer is used for touch pads, then the touch sensor can be manufactured easily, but contact resistance between touch pads and driver integrated circuit increases

Engineering Contradiction:

Improvetouch pad manufacturingVSAvoidcontact resistance

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The touch pad structure employs a composite multilayer design combining an opaque conductive layer with a transparent conductive layer. The opaque conductive layer ensures ease of manufacture and adequate conductivity, while the transparent conductive layer (with lower sheet resistance) is positioned to contact the driver integrated circuit, thereby reducing contact resistance and improving electrical reliability at the critical interface.

Inventive Principle:

Principle #40Composite materials

3Illumination intensity

If a blackened layer is added to prevent light reflection, then visibility is improved, but the device structure becomes more complex

Engineering Contradiction:

ImprovevisibilityVSAvoidmultilayer structure

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The patent merges the blackened layer with the existing opaque conductive layer structure. The black matrix layer is integrated into the touchscreen stack, combining light absorption functionality with the conductive electrode structure. This merging approach improves visibility by preventing light reflection while minimizing additional structural complexity by consolidating functions into a unified multilayer assembly.

Inventive Principle:

Principle #5Merging (Combining)

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

Enhances visibility by minimizing light reflection and reduces contact resistance between touch pads and the driver integrated circuit, thereby improving touch sensitivity and operational efficiency.

Implementation Method 1

the blackened layer may prevent reflection of external light

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 2

the partially transparent conductive layer may lower sheet resistance of the touch pads and thus contact resistance between the touch pads and a driver integrated circuit may be reduced

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentUS11782565B2Display device having one or more opaque conductive layers and blackened layers

Publication Date: 2023.10.10 LG DISPLAY CO LTD

AI summary

Disclosed is a display device having touch sensors which may improve visibility. In the display device, the touch sensors having a multilayer structure including a blackened layer are arranged on an encapsulation assembly arranged to cover light emitting elements, and touch pads having a multilayer structure including a partially transparent conductive layer are arranged on a region of a substrate exposed by the encapsulation assembly. Therefore, the blackened layer may prevent reflection of external light and thus visibility may be improved, and the partially transparent conductive layer may lower sheet resistance of the touch pads and thus contact resistance between the touch pads and a driver integrated circuit may be reduced.