In-Cell Touch Panel Counter Electrode Control
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Solution Overview
Problem
Conventional in-cell touch panels experience deteriorated touch detection performance when an unused electrode is formed on the counter substrate due to capacitance loads between touch sensor electrodes and the counter substrate, hindering the generation of capacitance between the touch sensor electrodes and indicators such as fingers or pens.
Innovation Solution
An in-cell touch panel configuration that includes a touch sensor substrate, a counter substrate with a non-used counter substrate electrode, a liquid crystal layer, and control circuits for mode switching between display and touch detection modes, where the counter substrate electrode receives a signal synchronized with the driving signal or is placed in a floating state during touch detection, reducing capacitance loads and maintaining touch detection performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If an electrode that is not used in touch detection is formed on the counter substrate, then the counter substrate can support additional functions (such as viewing angle switching), but capacitances that are loads are generated between the touch sensor electrodes and the counter substrate, which hinders the generation of capacitance between the touch sensor electrodes and indicators, resulting in deteriorated touch detection performance
Solution Approach 1:
The patent applies the dynamics principle by making the counter substrate electrode potential dynamic rather than static. The potential is switched between a fixed potential (during display mode) and a floating state (during touch detection mode). This dynamic adjustment allows the electrode to serve dual functions: supporting additional functions like viewing angle switching during display mode while minimizing capacitance loads during touch detection mode, thereby resolving the contradiction between functional versatility and touch detection performance
Solution Approach 2:
The patent applies the parameter changes principle by changing the electrical potential parameter of the counter substrate electrode based on the operation mode. During display mode, the electrode is maintained at a fixed potential to support functions like viewing angle switching. During touch detection mode, the potential is changed to a floating state to minimize capacitance loads. This parameter change enables the electrode to adapt its electrical characteristics to different operational requirements, resolving the contradiction between versatility and detection performance
2Reliability
If the counter substrate electrode is kept at a fixed potential to support functions like viewing angle switching, then the electrode can maintain its functional role, but capacitance loads are generated that hinder touch detection
Solution Approach 1:
The patent applies the periodic action principle by periodically switching the counter substrate electrode potential between fixed and floating states according to the operation mode transitions. During display mode, the fixed potential maintains electrode functionality; during touch detection mode, the floating state eliminates capacitance loads. This periodic switching between two potential states ensures that the electrode reliably supports its function when needed while minimizing harmful capacitance effects during touch detection
Solution Approach 2:
The patent applies the taking out principle by extracting the harmful capacitance load effect from the counter substrate electrode during touch detection mode. By switching the electrode to a floating state, the harmful capacitance connection is effectively removed or extracted from the touch detection circuit, allowing touch detection to proceed without interference while the electrode retains its structural and functional presence for other operations
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
This configuration effectively prevents the deterioration of touch detection performance by minimizing capacitance loads between the counter substrate electrode and touch sensor electrodes, allowing for accurate detection even with electrodes not used in touch detection on the counter substrate.
Implementation Method 1
a liquid crystal layer arranged between the touch sensor substrate and the counter substrate
Implementation Method 2
capacitances that are loads between the touch sensor electrodes and the counter substrate... the generation of capacitance between the touch sensor electrode and an indicator
Data Source
AI summary
An in-cell touch panel includes a mode switching control circuit and a counter substrate electrode control circuit. The mode switching control circuit switches, in a time-division manner, the operation mode of the in-cell touch panel between a display mode in which a display signal is supplied by a display control circuit to pixel electrodes, and a touch detection mode in which a driving signal is supplied by a driving control circuit to touch sensor electrodes. The counter substrate electrode control circuit supplies a counter substrate electrode with a signal that is in synchronization with the driving signal and that has the same polarity as that of the driving signal in a period while the in-cell touch panel is in the touch detection mode, or causes the potential of the counter substrate electrode to be in a floating state in a period while the in-cell touch panel is in the touch detection mode.