Sensing Electrode Layer Parasitic Capacitance Reduction
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Solution Overview
Problem
Integrated capacitance sensing display panels face issues with parasitic capacitance due to thinned glass in LCD panels, leading to signal coupling and errors in displaying and sensing functions, especially when the sensing electrode is integrated at certain positions.
Innovation Solution
A sensing electrode layer with alternately arranged first and second sensing electrodes, where each electrode unit consists of overlapping upper and lower patterns connected by contact structures, is implemented, along with a passivation layer to increase the distance between the sensing electrode layer and the electrode film, reducing parasitic capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the glass of the LCD panel is thinned out to meet lightness and slimness demands, then the lightness and slimness are improved, but the parasitic capacitance between the sensing electrode and the electrode film increases
Solution Approach 1:
A passivation layer is introduced as an intermediary between the sensing electrode layer and the electrode film. This passivation layer acts as a shielding layer that reduces the parasitic capacitance caused by the thinned glass structure, thereby resolving the harmful effect while maintaining the lightness and slimness improvements
2Device complexity
If the sensing electrode is integrated at position a or b in the LCD panel, then the integrated type sensing display panel becomes thinner and lighter, but the parasitic capacitance and signal coupling problems worsen
Solution Approach 1:
The passivation layer serves as a mediator that enables the integrated sensing electrode structure to maintain both thinness and signal accuracy. By inserting this shielding layer, the patent resolves the conflict between reduced panel thickness and maintained signal reliability
3Length of stationary object
If the distance between the sensing electrode and the electrode film is reduced, then the panel structure is more compact, but the signal coupling problem becomes much more serious
Solution Approach 1:
The passivation layer is positioned between the sensing electrode and the electrode film to act as a shielding barrier. This intermediary structure allows the electrodes to be closer for compactness while preventing harmful signal coupling through the dielectric properties of the passivation layer
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 solution effectively reduces parasitic capacitance and enhances sensitivity by ensuring the sensing electrodes operate with reduced signal coupling and improved signal accuracy.
Implementation Method 1
the glass of the LCD panel 100 which has been thinned out gives rise to an increase in parasitic capacitance between a sensing electrode and the electrode film 105
Data Source
AI summary
A display panel includes a first substrate, a second substrate, and a display medium. The display medium is sandwiched between the first substrate and the second substrate. The first substrate has a pixel array. The second substrate includes first sensing electrodes arranged in a first direction and second sensing electrodes arranged in a second direction. Each of the first sensing electrodes is formed by alternately arranging first upper sensing electrode patterns and first lower shading electrode patterns. Each of the first upper sensing electrode patterns is electrically connected to the adjacent first lower shading electrode patterns. Each of the second sensing electrodes is formed by alternately arranging second upper sensing electrode patterns and second lower shading electrode patterns. Each of the second upper sensing electrode patterns is electrically connected to the adjacent second lower shading electrode patterns.