Protective Layer Surface Modification for Display Touch Panel Cleaning

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Solution Overview

Problem

In display devices with integrated touch panels, foreign objects like glass shards from the cutting process adhere to the protective layer, which is hydrophobic, making them difficult to clean and risking damage during removal.

Innovation Solution

A display device design featuring a detection electrode with a protective layer and an optical film, where the surface adjacent to the optical film has a smaller water contact angle and increased surface roughness, allowing for easier removal of foreign objects using ultrasonic cleaning and reducing the risk of damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a protective layer is added to cover the detection electrode, then the electrode is protected, but glass shards from cutting process adhere to the protective layer and become difficult to remove

Engineering Contradiction:

Improveelectrode protectionVSAvoidcleaning difficulty

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The protective layer is designed with different surface properties on different sides: the first surface (facing the cutting process) has higher hydrophilicity and/or roughness to prevent glass shard adhesion, while the second surface (facing the optical film) maintains standard properties for proper optical performance. This local differentiation allows the protective layer to simultaneously provide protection and facilitate cleaning.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The surface characteristics of the protective layer are modified by changing physical parameters such as water contact angle (hydrophilicity) and surface roughness. The first surface is treated to have a larger water contact angle and/or greater surface roughness compared to the second surface, creating conditions that prevent glass shard adhesion and enable easy removal of contaminants.

Inventive Principle:

Principle #35Parameter changes

2Strength

If the protective layer is made hydrophobic, then it repels water, but cleaning liquid cannot enter the interface between glass shards and protective layer

Engineering Contradiction:

Improvewater repellencyVSAvoidcleaning effectiveness

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The protective layer exhibits different hydrophobicity levels on different surfaces. The first surface has higher hydrophilicity (larger water contact angle) to allow cleaning liquid penetration, while the second surface maintains appropriate hydrophobicity for optical performance. This spatial variation in surface energy properties resolves the contradiction between water repellency and cleaning effectiveness.

Inventive Principle:

Principle #3Local quality

3Ease of manufacture

If physical removal of glass shards is attempted, then they may be removed, but the protective layer can become damaged

Engineering Contradiction:

Improveglass shard removalVSAvoidprotective layer integrity

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent replaces mechanical/physical removal methods with chemical/cleaning-based removal. By modifying the surface properties to be more hydrophilic and/or rougher on the first surface, glass shards can be removed using cleaning liquids without applying mechanical stress that could damage the protective layer.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 design facilitates effective cleaning of foreign objects from the protective layer without damaging it, enhancing the manufacturing process and reducing the risk of damage during the cutting process.

Implementation Method 1

a first surface of the protective layer adjacent to the optical film has a smaller water contact angle compared to a second surface of the protective layer adjacent to the display cell

Methodology Applied

Scientific EffectHydrophility: Hydrophile

Implementation Method 2

performing a plasma process on a surface of the protective layer

Methodology Applied

Scientific EffectPlasma process: Plasma

Data Source

PatentUS10474260B2Display device

Publication Date: 2019.11.12 MAGNOLIA WHITE CORP

AI summary

The display device having a touch panel includes a detection electrode forming a touch panel and arranged on one surface of a display cell, a protective layer covering the detection electrode, and an optical film adhered to the protective layer, wherein a first surface of the protective layer adjacent to the optical film has a smaller water contact angle compared to a second surface of the protective layer adjacent to the display cell. The first surface of the protective layer is preferred to have a half or less the water contact angle compared to the second surface of the protective layer.