Capacitive Touch Screen Panel Electrode Configuration for Noise Reduction
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Solution Overview
Problem
Capacitive type touch screen panels suffer from low touch sensitivity and accuracy due to noise interference from liquid crystal panels, leading to false touch detections even without user input.
Innovation Solution
The design includes a first electrode with multiple patterns connected in the X-axis direction and a second electrode with patterns connected in the Y-axis direction, where the second electrode's area is reduced to minimize noise influence, and dummy patterns are added to reduce reflectivity differences and parasitic capacitance, optimizing the horizontal distance between electrode patterns to enhance touch sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the second electrode is exposed to the liquid crystal panel to enable touch sensing, then touch sensing function is achieved, but noise interference from the liquid crystal panel increases
Solution Approach 1:
The patent extracts and removes the harmful exposed portion of the second electrode that causes noise interference. By reducing the area of the second electrode and reconfiguring its patterns, the design eliminates the portion that is unnecessarily exposed to the liquid crystal panel, thereby removing the source of noise while preserving the essential touch sensing function.
Solution Approach 2:
The patent applies different patterns and configurations to different regions of the electrodes. The first electrode uses a grid pattern while the second electrode uses a reduced-area pattern, creating local variations in electrode properties. This allows the touch sensing function to be maintained in necessary regions while minimizing noise interference in other regions.
2Object-affected harmful factors
If the area of the second electrode is reduced to minimize noise influence, then noise interference decreases, but touch sensitivity may be compromised
Solution Approach 1:
The patent divides the second electrode into multiple discrete patterns rather than using a continuous large-area electrode. This segmentation allows the total area to be reduced for noise reduction while maintaining distributed sensing points that preserve touch sensitivity across the display surface.
Solution Approach 2:
The patent compensates for the reduced area of the second electrode by optimizing its vertical positioning and spacing relative to the first electrode. By adjusting the dimensional relationship between the two electrode layers, the design maintains adequate capacitive coupling for sensitive touch detection despite the reduced planar area.
3Volume of moving object
If the first electrode and second electrode are positioned close to each other for compact design, then device thickness is reduced, but parasitic capacitance increases
Solution Approach 1:
The patent creates an asymmetric configuration where the first electrode has a larger area than the second electrode. This asymmetric design allows the electrodes to be positioned close together for compactness while the area difference helps manage parasitic capacitance by reducing the overlapping area between the two electrodes.
Solution Approach 2:
The patent uses a grid pattern for the first electrode that provides sufficient coverage for driving functions without excessive area. This partial coverage approach maintains compact device thickness while limiting the total overlapping area with the second electrode, thereby controlling parasitic capacitance to acceptable levels.
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 improves touch sensitivity by reducing parasitic capacitance and noise interference, while maintaining visibility and reducing the impact of external pressures on touch accuracy.
Implementation Method 1
the capacitive type senses a change of capacitance according to a user's touch
Implementation Method 2
the exposed portion of the second electrode 130 is influenced by noise generated in the liquid crystal panel 110
Data Source
AI summary
Disclosed is a touch screen panel for improving touch sensitivity, the screen panel comprising a first electrode in a first direction; and a second electrode, insulated from the first electrode, in a second direction perpendicular to the first direction, wherein the first electrode includes a plurality of first patterns, and a second pattern formed as one body with the plurality of first patterns so as to connect the plurality of first patterns in the first direction; the second electrode includes a plurality of third patterns, and a fourth pattern formed as one body with the plurality of third patterns so as to connect the plurality of third patterns in the second direction; and the first pattern is provided at a predetermined distance in a horizontal direction from the third pattern, the second pattern crosses the fourth pattern, and an area of the first electrode is larger than an area of the second electrode.