Touch Screen Shield Wiring Comb-Teeth ESD Breakdown
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Solution Overview
Problem
Projected capacitive touch panels are prone to breakdown due to electrostatic discharge, particularly at the termination points of row and column wirings where lead-out connections are absent, leading to potential electrical breakdown.
Innovation Solution
Incorporating comb-teeth shaped parts on the row and column wirings and a shield wiring to reduce the distance between them, which increases electrostatic discharge convergence and minimizes voltage differences, thereby reducing the likelihood of breakdown.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If lead-out wirings are connected to only terminal parts on one side of row wirings and column wirings, then device complexity is reduced, but reliability deteriorates due to electrostatic discharge accumulation on unconnected sides
Solution Approach 1:
A shield wiring is introduced as an intermediary component between the row wirings/column wirings and the external environment. This shield wiring acts as a mediator that captures and dissipates electrostatic discharge, preventing direct damage to the detection wirings while maintaining the simplified single-side connection structure
Solution Approach 2:
The shield wiring is positioned and configured in advance to intercept electrostatic discharge before it can reach the row wirings and column wirings. By establishing this protective barrier beforehand, the system is cushioned against potential breakdown, allowing the wirings to remain connected on only one side without compromising reliability
2Reliability
If shield wiring is positioned close to row wirings and column wirings, then electrostatic discharge protection is improved, but manufacturing precision requirements increase
Solution Approach 1:
The shield wiring is arranged in a dimensional configuration that surrounds or encloses the row wirings and column wirings, creating a three-dimensional protective structure. This spatial arrangement allows effective electrostatic discharge protection while maintaining larger lateral distances, thereby reducing manufacturing precision requirements for wiring spacing
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 configuration effectively reduces the occurrence of breakdowns during electrostatic discharges, ensuring a more reliable touch screen operation even under higher voltage conditions.
Implementation Method 1
when a pointing body (conductor) such as a finger coming close to the touch panel generates an electrostatic discharge
Implementation Method 2
detecting a change in an electric field, in other words, a mutual capacitance
Data Source
AI summary
A touch screen according to the present invention includes: a transparent substrate; a plurality of row-direction wirings and a plurality of column-direction wirings provided on the transparent substrate, the row-direction wirings and the column-direction wirings intersecting via an inter-layer insulating film with each other in a stereoscopic view; a plurality of lead-out wirings each provided to be electrically extended from each of first ends of the said row-direction wirings and the column-direction wirings; and a shield wiring provided to surround in a planar view the row-direction wirings, the column-direction wirings, and the lead-out wirings, wherein the row-direction wirings, the column-direction wirings, and the shield wiring have comb-teeth parts which are formed to have comb-teeth shapes such that distances from the shield wiring to the row-direction wirings and the column-direction wirings are small at predetermined parts.