Touch Panel Electrode Grid Noise Cancellation
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Solution Overview
Problem
Conventional touch panel systems are inadequate in removing a wide variety of noises and often suffer from issues like moire patterns and decreased position detection precision due to electrode arrangements and materials used, particularly when integrated with display devices.
Innovation Solution
A touch panel system with a main sensor section and a sub sensor section, where the sub sensor section detects noise signals, and a subtracting section calculates differences between adjacent sense lines to isolate and remove noise from the main sensor's output, utilizing a uniform grid of vertical and horizontal electrodes with an insulator in between to prevent moire and enhance noise cancellation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional touch panel system uses a single sensor section, then the device complexity is low, but the noise removal capability is insufficient
Solution Approach 1:
The sensor is divided into multiple independent sensor sections (first sensor section and second sensor section) that can detect different signals. The first sensor section detects touch operation signals while the second sensor section detects noise signals, allowing independent processing of each signal type to achieve effective noise removal without excessive complexity
Solution Approach 2:
The noise signal detection function is extracted into a separate second sensor section, allowing the main touch detection function to remain in the first sensor section. This extraction enables independent optimization of each function and simplifies the overall signal processing by separating noise removal from touch detection
2Measurement precision
If diamond-shaped electrodes are used in a conventional capacitive touch panel, then the manufacturing process is simplified, but moire patterns occur and position detection precision decreases
Solution Approach 1:
The patent uses rectangular electrodes instead of symmetric diamond-shaped electrodes. This asymmetric shape design eliminates the moire pattern formation that occurs with diamond-shaped electrodes when viewed through certain angles, while also improving position detection precision by providing more distinct capacitance variation patterns across the sensor surface
Solution Approach 2:
The patent applies different electrode shapes and orientations in different regions of the sensor panel. The first and second sensor sections use rectangular electrodes with specific orientations that are optimized for their respective functions, allowing each region to have the local quality needed for its specific detection purpose
3Reliability
If ITO or graphene is used as electrode material, then the transparency is improved, but the resistance value becomes too high for large-scale panels
Solution Approach 1:
The patent employs a composite electrode structure combining transparent conductive material (ITO or graphene) with metal wire grids. The transparent conductive material provides transparency and base conductivity, while the metal wire grid overlay provides additional conductive pathways, creating a composite structure that achieves both transparency and low resistance even in large-scale panels
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 effectively cancels a wide range of noise signals, improves detection sensitivity, and prevents moire patterns, ensuring reliable operation on display devices by isolating noise components from touch operation signals.
Implementation Method 1
an insulator provided between the vertical electrode surface and the horizontal electrode surface to insulate the vertical electrodes from the horizontal electrodes
Implementation Method 2
a capacitive sensor provided with a sense line extending along a direction in which the sense lines extend
Data Source
AI summary
A touch sensor panel disclosed herein includes: a plurality of vertical electrodes (6); and a plurality of horizontal electrodes (7), the plurality of vertical electrodes (6) and the plurality of horizontal electrodes (7) (i) being so disposed that, as viewed in the direction perpendicular to a substrate, the plurality of vertical electrodes (6) include no segment coincident with the plurality of horizontal electrodes (7) and (ii) forming a uniform grid having no gap.