Touch Panel Routing Line Shielding via Transparent Conductive Layer
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Solution Overview
Problem
Existing touch panels are susceptible to noise from external static electricity and Electromagnetic Interference (EMI) due to exposed routing lines, which can cause malfunction when attached to liquid crystal display devices.
Innovation Solution
A touch panel design featuring a substrate with first and second electrodes in a row and column direction, pad electrodes, routing lines, and a transparent conductive layer at the peripheral region to shield external static electricity, with the transparent conductive layer connected to a guide ring line and applying a ground or constant voltage to prevent interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If routing lines are exposed from the substrate to connect electrodes and pad electrodes, then connection and signal transmission are enabled, but noise from external static electricity infiltrates and affects touch panel driving
Solution Approach 1:
A transparent conductive layer is introduced as an intermediary component between the routing lines and the external environment. This layer acts as a shield that blocks noise from external static electricity while allowing the routing lines to maintain their electrical connection function. The transparent conductive layer is connected to a guide ring line that provides a reference potential, creating an electromagnetic shielding effect without interfering with the routing lines' signal transmission capability.
2Ease of manufacture
If routing lines are positioned at the peripheral region for connection, then ease of connection to display device circuits is improved, but EMI interference occurs when the underlying display device is driven
Solution Approach 1:
The transparent conductive layer serves as an electromagnetic shielding intermediary that separates the routing lines from the interfering EMI fields generated by the display device circuits. By positioning this shielding layer over the routing lines in the peripheral region, the patent enables close proximity connection to display device circuits while maintaining signal integrity through electromagnetic isolation.
Solution Approach 2:
The patent replaces physical distance separation (mechanical solution) with electromagnetic shielding (field-based solution). Instead of moving routing lines far away from display device circuits to avoid EMI, the transparent conductive layer provides active electromagnetic protection, allowing the routing lines to remain in optimal connection positions while being shielded from interference.
3Reliability
If a shielding structure is added to protect routing lines from noise and EMI, then reliability is improved, but device complexity increases
Solution Approach 1:
The transparent conductive layer is formed using the same material and manufacturing process as the existing transparent electrodes in the touch panel. This homogeneity in material selection and fabrication method allows the shielding function to be integrated into the existing touch panel structure without requiring additional complex processing steps or different material systems, thereby minimizing the increase in device complexity.
Solution Approach 2:
The transparent conductive layer serves multiple functions simultaneously: it provides electromagnetic shielding for the routing lines, maintains optical transparency for the touch panel display, and can be integrated with the existing transparent electrode structure. This multi-functionality reduces the need for separate dedicated shielding components, thereby limiting the increase in overall device complexity while achieving improved reliability.
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 effectively shields external static electricity and prevents EMI, ensuring reliable touch detection and operation without affecting the underlying display panel's drive.
Implementation Method 1
a transparent conductive layer formed at the peripheral region to cover the routing lines
Implementation Method 2
a guide ring line formed on the substrate to surround an inner region of the routing lines... the guide ring line and the transparent conductive layer... prevent EMI interference
Data Source
AI summary
The present invention relates to a touch panel which can detect touch securely without being affected by drive of an underlying display panel and shield external static electricity, securely, the touch panel includes a substrate having an active region and a peripheral region surrounding the active region; a plurality of first electrodes and second electrodes formed on the active region in a row direction and a column direction, respectively; a plurality of pad electrodes on one side of the peripheral region; routing lines for connecting ends of the first electrodes and the second electrodes to the pad electrodes, respectively; and a transparent conductive layer formed at the peripheral region to cover the routing lines.