Capacitive and Piezoelectric Touch Sensing Device
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Solution Overview
Problem
Capacitive sensing methods for touch surfaces require substantial power, scanning time, and signal processing capability to determine touch locations, making them inefficient in terms of power consumption and processing time.
Innovation Solution
A device comprising a capacitive sensor array and piezoelectric sensors, where the detection unit receives piezoelectric sensor signals to identify touch locations, allowing for partial or parallel scanning of the touch surface, reducing power consumption and processing time while maintaining accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a full scan of the capacitive sensor array is performed to determine touch location, then measurement precision is improved, but use of energy increases and scanning time increases
Solution Approach 1:
The touch surface is divided into multiple sections, each monitored by piezoelectric sensors. The capacitive sensor array is segmented into subsets corresponding to these sections. When a piezoelectric sensor detects a touch, only the corresponding subset of capacitive sensors is activated for scanning, rather than scanning the entire array. This segmentation enables localized scanning that maintains detection accuracy while reducing power consumption and scanning time.
2Measurement precision
If a full scan of the capacitive sensor array is performed to determine touch location, then measurement precision is improved, but scanning time increases
Solution Approach 1:
Piezoelectric sensors continuously monitor the touch surface in advance to detect touch events. When a touch is detected by a piezoelectric sensor, this preliminary detection triggers the activation of only the corresponding subset of capacitive sensors for localized scanning. This preliminary action by piezoelectric sensors eliminates the need to scan the entire capacitive sensor array, significantly reducing scanning time while maintaining accurate touch location detection.
3Measurement precision
If a full scan of the capacitive sensor array is performed to determine touch location, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The capacitive sensor array is divided into multiple subsets, each corresponding to a section of the touch surface monitored by piezoelectric sensors. When a touch is detected, only the relevant subset of capacitive sensors is activated for scanning. This segmentation reduces the number of sensors that need to be processed simultaneously, thereby reducing signal processing complexity and device requirements while maintaining accurate touch location detection through localized scanning.
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 enables touch location detection with lower power consumption, shorter scanning time, and reduced signal processing requirements, achieving a better accuracy-to-power and accuracy-to-processing time ratio compared to full scans.
Implementation Method 1
A plurality of piezoelectric sensors 102 are mechanically coupled to the touch surface 101
Implementation Method 2
A capacitive sensor array 200 is capacitively coupled to the touch surface 101
Data Source
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AI summary
It is an object to provide a device for capacitive and piezoelectric touch sensing. According to an embodiment, a device (100), comprises a touch surface (101); a capacitive sensor array capacitively coupled to the touch surface (101); and a plurality of piezoelectric sensors (102) mechanically coupled to the touch surface (101). A detection unit (105) is configured to: receive a piezoelectric sensor signal from at least one emitting piezoelectric sensor of the plurality of piezoelectric sensors (102), scan at least part of the touch surface (101) using the capacitive sensor array and identify a touch location on the touch surface based on the scan and on the at least one emitting piezoelectric sensor (102) .