Display Touch Electrode Shielding for Parasitic Capacitance Reduction
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Solution Overview
Problem
Touch sensitivity in display devices is lowered due to parasitic capacitance generated between the touch electrode and the cathode electrode.
Innovation Solution
A display device with a shielding electrode is introduced that partially overlaps the touch electrode, reducing parasitic capacitance and noise by applying a voltage to shield the potential difference between the touch and cathode electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a touch electrode is disposed close to the cathode electrode to improve touch sensitivity, then touch sensing capability is enhanced, but parasitic capacitance increases causing noise and reducing touch sensitivity
Solution Approach 1:
A shielding electrode is introduced as an intermediary component between the touch electrode and the cathode electrode. This shielding electrode is disposed on the encapsulation layer and electrically connected to a shielding electrode pad, creating an intermediate layer that blocks the direct capacitive coupling between the touch electrode and cathode electrode, thereby reducing parasitic capacitance noise while maintaining touch sensing capability
2Object-affected harmful factors
If the shielding electrode is positioned to overlap the touch electrode, then parasitic capacitance is reduced, but device structure becomes more complex
Solution Approach 1:
The shielding electrode serves multiple functions simultaneously: it acts as a noise shielding layer to reduce parasitic capacitance, provides an additional structural layer for encapsulation protection, and can be integrated with existing encapsulation layer materials and processes. This multi-functionality approach reduces the need for separate dedicated shielding structures, thereby minimizing the increase in device complexity
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 touch sensing performance by reducing noise and improving touch sensitivity through the use of a shielding electrode that minimizes parasitic capacitance.
Implementation Method 1
parasitic capacitance generated between the touch electrode and an electrode (e.g., the cathode electrode) of the display panel
Implementation Method 2
the shielding electrode shields noise due to the parasitic capacitance generated between the cathode electrode and the touch electrode
Data Source
AI summary
A display device according to an embodiment comprises a substrate including a display area where subpixels are disposed and a non-display area outside the display area, each of the subpixels including an anode electrode, a light emitting layer, and a cathode electrode for displaying an image, an encapsulation layer positioned on the substrate, a shielding electrode positioned on the encapsulation layer, an intermediate organic layer positioned on the shielding electrode, a touch electrode positioned on the intermediate organic layer, a touch insulation layer positioned on the touch electrode, a shielding electrode line electrically connected with the shielding electrode, and a shielding electrode pad electrically connected with the shielding electrode line. The shielding electrode receives a voltage through the shielding electrode pad.