Capacitive Touch Panel Sensing Using Out-of-Phase Charge Signals
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Solution Overview
Problem
Conventional two-dimensional capacitive-sensing touch panels require an increased number of sensing pads and reduced pad areas to enhance sensing resolution, leading to higher hardware costs and complexity.
Innovation Solution
A method and device that utilize M signal transmitting lines and N signal receiving lines to generate characteristic values for neighboring regions by applying out-of-phase charge/discharge signals, allowing for the estimation of control point positions without increasing the number of signal lines, thereby improving sensing resolution at reduced costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the amount of sensing pads is increased and areas of the sensing pads are reduced to increase sensing resolution, then sensing resolution is improved, but hardware costs and device complexity increase
Solution Approach 1:
The patent combines multiple sensing functions into a single neighboring region unit. Each neighboring region is defined by two sets of signal transmitting lines and two sets of signal receiving lines, forming a integrated sensing unit that detects control points. This merging approach allows the system to achieve high sensing resolution without proportionally increasing the total number of sensing pins, as adjacent lines are shared across multiple neighboring regions.
2Measurement precision
If the amount of sensing pads is increased and areas of the sensing pads are reduced to increase sensing resolution, then sensing resolution is improved, but hardware costs increase
Solution Approach 1:
The signal transmitting lines and signal receiving lines serve multiple functions simultaneously. Each set of lines participates in defining multiple neighboring regions and is reused across different sensing operations. This multi-functionality reduces the total quantity of sensing components required, thereby lowering hardware costs while maintaining high sensing resolution through the systematic arrangement of shared lines.
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 increases sensing resolution by two times in two dimensions and overall resolution by four times, while maintaining the same wiring density, without the need for additional signal lines, thus addressing the cost and complexity issues of conventional systems.
Implementation Method 1
M signal transmitting lines, N signal receiving lines and M*N capacitors formed at neighboring regions of the signal transmitting lines and signal receiving lines
Data Source
AI summary
For sensing a control point on a capacitive-type panel, first and second voltage signals are respectively received through two sets of receiving lines selected from N receiving lines in response to first and second charge/discharge signals transmitted through two sets of transmitting lines selected from M transmitting lines, respectively, during a specified time period. A characteristic value is generated by operating the first and second voltage signals. Repeat the steps to generate characteristic values for neighboring regions defined by different combinations of transmitting lines and receiving lines. Position information of control point(s) on the capacitive-type panel is estimated accordingly.