Resonant Circuit Touch Detection Frequency Differentiation
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Solution Overview
Problem
Existing touch detection devices and panels face issues with noise interference and inaccurate stylus pen/finger differentiation due to signal amplitude variations and region-based determination methods.
Innovation Solution
A touch detection device utilizing a plurality of resonant circuits along the touch detection surface, which generates and compares output signal frequencies to determine stylus pen or finger operations based on predetermined threshold values, reducing noise interference and improving accuracy through frequency-based differentiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If signal amplitude is used for touch detection, then touch operation can be detected, but false detection occurs due to noise interference
Solution Approach 1:
The patent changes the detection parameter from signal amplitude to frequency. By detecting frequency shifts in the resonant circuit caused by touch operations, the system achieves noise immunity since frequency information remains stable even when amplitude varies due to noise interference.
Solution Approach 2:
The patent replaces the conventional capacitive detection method with a resonant circuit-based frequency detection method. This substitution transforms the detection mechanism from measuring electrical capacitance changes to measuring frequency changes, thereby eliminating susceptibility to display noise.
2Measurement precision
If region-based method is used for stylus pen/finger determination, then touch type can be identified, but incorrect determination occurs
Solution Approach 1:
The patent changes the determination criterion from touch region area to frequency shift magnitude. By comparing the degree of frequency change in the resonant circuit, the system can accurately distinguish between stylus pen touches (larger frequency shift) and finger touches (smaller frequency shift), eliminating incorrect determinations.
3Measurement precision
If capacitive method with multiple electrodes is used, then touch operation can be detected, but signal amplitude varies due to noise
Solution Approach 1:
The patent transitions from amplitude-based detection to frequency-based detection. The resonant circuit's frequency response to touch operations provides a stable measurement parameter that is not affected by display noise, thereby maintaining measurement precision while eliminating noise interference.
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 false detections caused by noise and enhances stylus pen/finger differentiation accuracy by using frequency variations, resulting in a more reliable touch operation detection system.
Implementation Method 1
a plurality of resonant circuits arranged along a touch detection surface; a signal input unit for inputting, to each of the plurality of resonant circuits, an input signal for causing resonance
Implementation Method 2
The capacitive method is a method of detecting the touch operation by arranging a plurality of electrodes along the touch detection surface, and detecting a change in capacitance between the electrodes caused by approach of, for example, a finger of the user
Data Source
AI summary
Provided is a touch detection device, including: a plurality of resonant circuits arranged along a touch detection surface; an input signal line for inputting, to each of the plurality of resonant circuits, an input signal for causing resonance; and a detecting unit for detecting frequencies of a plurality of output signals output from the plurality of resonant circuits.