Display Touch Panel With X-Y Dummy Electrodes for Noise Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrostatic capacitive touch panels suffer from increased line capacitance due to intersecting signal lines, leading to reduced signal-to-noise ratio and detection sensitivity, especially when used with display devices, which can cause erroneous operation and decreased performance.
Innovation Solution
The design minimizes line capacitance by orthogonal intersection of signal lines on a flexible printed circuit board, equalizes electrode capacitance between X and Y directions, and incorporates a transparent conductive film to shield noise from the display panel, while supplying signals to electrodes from both ends to enhance detection sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If signal lines are arranged to supply signals to electrodes, then electrode functionality is achieved, but line capacitance increases causing reduced signal-to-noise ratio
Solution Approach 1:
The patent introduces a third dimension by stacking signal lines in multiple layers (first signal line in first layer, second signal line in second layer) to achieve orthogonal routing. This vertical stacking allows X-direction and Y-direction signal lines to intersect without physical contact, minimizing capacitive coupling while maintaining electrical connectivity to all electrodes.
Solution Approach 2:
The patent introduces dummy electrodes as intermediary elements positioned between adjacent electrode groups. These dummy electrodes act as capacitive buffers that equalize the total capacitance between X and Y direction electrodes, preventing signal distortion and maintaining balanced detection sensitivity across both axes.
2Measurement precision
If X and Y electrodes have different capacitance values, then directional detection sensitivity becomes uneven, but equalizing capacitance requires additional components
Solution Approach 1:
The patent transitions from planar electrode arrangement to three-dimensional stacking where X and Y electrodes are positioned at different vertical levels. This spatial separation reduces parasitic coupling between orthogonal electrodes while maintaining uniform capacitance values through the dummy electrode compensation mechanism.
Solution Approach 2:
The patent applies different capacitance compensation strategies to different regions: dummy electrodes are selectively positioned between specific electrode groups (e.g., between first and second X electrodes, or between first and second Y electrodes) to locally balance capacitance where needed, rather than uniformly modifying all electrodes.
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 approach results in a highly reliable electrostatic capacitive touch panel with improved detection sensitivity and reduced noise interference, ensuring accurate finger touch input recognition.
Implementation Method 1
incorporates a transparent conductive film to shield noise from the display panel
Implementation Method 2
an electrostatic capacitive type touch panel which includes... detects coordinates of a position touched by the viewer by detecting coupled capacitance
Data Source
AI summary
A display device includes a display panel, and an electrostatic capacitive type touch panel which is formed in an overlapping manner with the display panel. A plurality of X electrodes and a plurality of Y electrodes intersecting with the X electrodes. A first signal line supplies signals to the X electrodes, a second signal line supplies signals to the Y electrodes, and the first signal line and the second signal line are formed on a flexible printed circuit board. A dummy electrode is formed adjacent to an electrode portion of each X electrode and electrode portion of each Y electrode, the dummy electrode does not overlap the X electrode and the Y electrode, and the dummy electrode does not electrically connect with the first and second signal lines.