Mutual Capacitive Touch Panel Double-Layer Electrode Structure
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Solution Overview
Problem
Conventional double-layer electrode mutual capacitive touch panels experience inaccurate detection when a touching object moves in a straight line due to the structural design, which results in a non-straight motion trajectory measurement, primarily because of the need for conductive lines connecting sensing series across the panel's border regions, leading to fluctuations in X-axis position detection.
Innovation Solution
A mutual capacitive touch panel with a double-layer electrode structure is designed to enhance detection accuracy by using a first conductive layer with electrodes connected in series and a second conductive layer with electrode strip groups that include shielding portions to effectively shield connecting line segments, reducing the impact of coupling capacitance and improving touch accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If connecting lines are used to electrically connect sensing series from two sides of the sensing series, then the electrical connection is achieved, but the width of border regions cannot be reduced
Solution Approach 1:
The patent transitions from horizontal connection (conventional approach) to vertical connection by stacking conductive layers. The first and second conductive layers are arranged vertically with insulation layers between them, allowing electrical connection in the thickness dimension rather than the planar dimension, thus reducing border region width.
Solution Approach 2:
The patent embeds multiple conductive layers and insulation layers within each other in a vertical stack. The first conductive layer, insulation layer, and second conductive layer are nested vertically, with each layer containing embedded electrodes and connecting line segments that interconnect through the stack.
2Device complexity
If driving series are divided into two driving series to reduce conductive lines, then the number of conductive lines is reduced, but detection accuracy deteriorates due to trajectory fluctuation
Solution Approach 1:
The patent applies different functional qualities to different parts of the electrode structure. The first conductive layer contains electrodes for one direction (e.g., horizontal) while the second conductive layer contains electrodes for the perpendicular direction (e.g., vertical). Each layer is optimized for its specific function, with embedded electrodes and connecting line segments configured to minimize interference and improve detection accuracy in their respective directions.
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 proposed design significantly reduces errors in X-axis position detection, with the detected trajectory closely matching the actual motion trajectory, enhancing overall detection accuracy and reducing the width of the border regions by minimizing the number of conductive lines.
Implementation Method 1
Each of the electrode strips includes a plurality of strip portions and a plurality of shielding portions, wherein the strip portions and the shielding portions are alternately connected in series along the row direction of the array. Each of the first strips is provided correspondingly to one of the electrodes, and each of the shielding portion overlaps, in the perpendicular projection direction, one corresponding of the connecting line segments.
Data Source
AI summary
The present invention provides a mutual capacitive touch panel including a first conductive layer and a second conductive layer. The first conductive layer includes a plurality of electrodes arranged in an array and a plurality of connecting line segments. In each column of the array, the electrodes in the ((N×M)-1)th row are electrically connected to one another through some of the connecting line segments to form a first electrode series, and the electrodes in the (N×M)th row are electrically connected to one another through some of the connecting line segments to form a second electrode series. The second conductive layer includes a plurality of electrode strips extending along a row direction of the array and respectively overlapping the electrodes located at the corresponding row. Each electrode strip includes a plurality of shielding portions, each of which overlaps one corresponding of the connecting line segments.