Touch Panel Noise Removal via Differential Signal Subtraction
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Solution Overview
Problem
Conventional touch panel systems are unable to reliably remove a wide variety of noises, as they primarily focus on removing AC signal components and assume impulse noise, failing to address other noise types effectively.
Innovation Solution
The touch panel system incorporates a main sensor and a sub sensor on the same surface, with a subtracting section that finds the difference between signals from both sensors to isolate and remove noise components, allowing for the reliable cancellation of various noise types.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a filter section extracts AC signal components for noise removal, then impulse noise can be removed, but other types of noise cannot be reliably canceled
Solution Approach 1:
The sensor section is segmented into multiple independent sensor elements (first sensor element, second sensor element, etc.) arranged in specific patterns. Each sensor element captures noise components, and the controller processes signals from different sensor elements to remove various noise types through differential processing, enabling comprehensive noise coverage without relying on a single filter approach
Solution Approach 2:
Multiple sensor elements are arranged to create replicated sensing points that experience similar noise environments. The controller uses these replicated signals to construct noise models and subtract them from the main sensor signals, enabling effective removal of multiple noise types including display device noise, external noise, and impulse noise
2Adaptability or versatility
If multiple sensor elements are arranged in specific patterns to capture noise components, then various noise types can be removed, but the device complexity increases
Solution Approach 1:
The sensor elements serve multiple functions: they detect touch operations, capture noise components for processing, and provide differential signals for noise removal. The same sensor array structure used for touch detection also enables comprehensive noise measurement and cancellation, eliminating the need for separate dedicated noise sensors and reducing overall system complexity
Data Source
AI summary
Provided is a touch panel system (1) capable of reliably removing a wide variety of noises. The touch panel system (1) includes a main sensor (31) which detects a touch operation, a sub sensor (32) which does not detect a touch operation but detects a noise component, and a subtracting section (41) which subtracts, from an output signal of the main sensor (31), an output signal of the sub sensor (32). The subtracting section (41) performs a subtracting operation to remove a noise component from the output signal of the main sensor (31), thereby extracting a signal derived from the touch operation itself.