In-cell Touch Panel Wire Reduction via Electrode Grouping
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Solution Overview
Problem
In-cell touch panels require a large number of wires to determine touch positions, leading to increased manufacturing costs and complexity.
Innovation Solution
The touch panel design alternates self-capacitance electrodes into groups connected by fewer wires, reducing the total number of wires needed by arranging them in columns or rows, with each group sharing a single wire, thereby decreasing the number of wires required to connect to the touch sensing unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If each self-capacitance electrode is connected to the touch sensing unit via a separate wire, then accurate touch position determination is achieved, but the number of wires increases significantly
Solution Approach 1:
Multiple self-capacitance electrodes that are adjacent to each other are electrically connected through the same wire. Specifically, electrodes in the first column are grouped into n/m sets where each set shares a common first wire, and electrodes in the second column are grouped into m sets where each set shares a common second wire. This merging of multiple electrode connections into fewer wires reduces the total wire count from 2n to n/m + m while maintaining the ability to detect touch positions through capacitance changes on individual electrodes.
Solution Approach 2:
Each wire serves multiple functions by connecting to multiple electrodes. The first wire connects to n/m electrodes in the first column, and the second wire connects to m electrodes in the second column. This multi-functionality allows the same wire to carry signals from multiple electrodes, reducing the overall wiring complexity while preserving touch detection capabilities across all electrodes.
2Ease of manufacture
If the number of wires is reduced by grouping electrodes, then manufacturing cost and complexity decrease, but touch detection capability must be maintained
Solution Approach 1:
The array of self-capacitance electrodes is segmented into two columns, with the first column containing electrodes connected via first wires and the second column containing electrodes connected via second wires. Within each column, electrodes are further segmented into groups (n/m sets in the first column, m sets in the second column) that share common wires. This segmentation allows systematic reduction of wire count while preserving individual electrode detection capability through the maintained electrical connection to the touch sensing unit.
Solution Approach 2:
The wiring structure transitions from a one-to-one correspondence (each electrode has its own wire) to a many-to-one correspondence (multiple electrodes share wires) by introducing a grouping dimension. The electrodes are organized in a two-column array structure where the grouping occurs along the column dimension, creating a hierarchical connection structure that reduces wiring complexity while maintaining detection 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
This design significantly reduces the number of wires needed, enhancing manufacturing efficiency and reducing costs, especially when the number of electrodes is large, while maintaining accurate touch position determination.
Implementation Method 1
when the panel is not touched by a human body, the capacitance withstood by each self-capacitance electrode is a fixed capacitance; but when the panel is touched by a human body, the capacitance withstood by the corresponding self-capacitance electrode is the fixed capacitance plus a body capacitance
Data Source
AI summary
An in cell touch panel, a touch detection method and a display device. The in-cell touch panel comprises: a substrate, a plurality of self-capacitance electrodes located on said substrate and arranged in an array, and a touch sensing unit for determining the touch position by sensing capacitance value changes on the self-capacitance electrodes. The number of elements in each column of self-capacitance electrodes is n and there is a submultiple m of n, and a first column of self-capacitance electrodes includes n/m groups of self-capacitance electrodes divided in the sequence of column adjacency. Each group includes m self-capacitance electrodes and the self-capacitance electrodes in the same group are electrically connected by the same wire. The second column of self-capacitance electrodes include m groups of self-capacitance electrodes, each group includes n/m self-capacitance electrodes and the self-capacitance electrodes in the same group are electrically connected by a second wire.