Display Device Intermediate Layer Touch Sensitivity

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Solution Overview

Problem

Conventional touchscreen manufacturing processes are complicated due to the attachment step and suffer from reduced touch sensitivity due to high dielectric constant adhesives, which increase parasitic capacitance between touch sensors and light-emitting elements.

Innovation Solution

A display device design featuring a light-emitting element, an encapsulation unit, and a touch sensor with an intermediate layer comprising first and second intermediate layers, where the first layer has a lower dielectric constant than the organic film and extends into non-active areas, and the second layer has greater hardness than the first, improving touch sensitivity while simplifying the manufacturing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional adhesive is used to attach the touchscreen to the display panel, then the touchscreen can be attached to the front of the display panel, but the parasitic capacitance between the touch sensor and light-emitting element is increased and touch sensitivity is reduced

Engineering Contradiction:

Improvetouch sensitivityVSAvoidparasitic capacitance

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

An intermediate layer is introduced between the touchscreen and the display panel to replace the conventional adhesive. This intermediate layer has a lower dielectric constant than conventional adhesives, thereby reducing the parasitic capacitance between the touch sensor and light-emitting element while still providing the necessary attachment function. The intermediate layer acts as a mediator that resolves the conflict between attachment reliability and parasitic capacitance reduction.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The dielectric constant parameter of the adhesive material is changed by selecting materials with lower dielectric constants for the intermediate layer. This parameter change directly reduces the parasitic capacitance in the touch sensor structure, improving touch sensitivity while maintaining the attachment function.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the touchscreen is separately manufactured and attached to the display panel, then the touchscreen can be attached to the front of the display panel, but the manufacturing process becomes complicated due to the addition of an attachment step

Engineering Contradiction:

Improveattachment reliabilityVSAvoidmanufacturing process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The intermediate layer is integrated into the display panel manufacturing process, merging the attachment function with the existing manufacturing steps. Instead of separately manufacturing and attaching the touchscreen as a distinct step, the intermediate layer is formed as part of the overall device structure, combining multiple functions into a unified process flow.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The intermediate layer serves multiple functions simultaneously: it provides attachment between the touchscreen and display panel, reduces parasitic capacitance, and can serve as part of the encapsulation structure. This multi-functionality eliminates the need for separate attachment steps and materials, simplifying the overall manufacturing process.

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

The solution enhances touch sensitivity and simplifies the manufacturing process by reducing parasitic capacitance and preventing crack formation, allowing for improved performance and reduced complexity in the manufacturing of display devices.

Implementation Method 1

the first intermediate layer has a dielectric constant that is lower than a dielectric constant of an organic film disposed above or under the intermediate layer

Methodology Applied

Scientific EffectDielectric constant: Dielectric Permittivity

Implementation Method 2

the second intermediate layer has greater hardness than the first intermediate layer, whereby touch sensitivity is further improved

Methodology Applied

Scientific EffectHardness:

Data Source

PatentUS11264435B2Display device

Publication Date: 2022.03.01 LG DISPLAY CO LTD

AI summary

Disclosed is a display device capable of being manufactured through a simplified process and having improved touch sensitivity. The display device includes an encapsulation unit disposed on a light-emitting element, a touch sensor disposed on the encapsulation unit, and an intermediate layer disposed between the encapsulation unit and the touch sensor. The intermediate layer includes a first intermediate layer, having a dielectric constant that is lower than a dielectric constant of an organic film disposed above or under the intermediate layer, and a second intermediate layer, having greater hardness than the first intermediate layer, whereby touch sensitivity is improved while processing is simplified.