Acoustic Touch Sensing Through Housing to Resist Liquid Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current touch sensors, particularly capacitive touch sensors, are prone to interference from external factors such as liquids, leading to high false touch rates. Additionally, piezoresistive touch sensors are sensitive to temperature changes, and compressive touch sensors require high rigidity in the electronic product housing and significant user force for operation.
Innovation Solution
A touch sensor device comprising a housing with a touch region and at least one sensor, which includes a signal transmitting unit generating a vibration signal under an excitation signal, a signal receiving unit receiving the vibration signal and generating an output signal, and a processor recognizing touch operations based on the output signal. The sensor can include piezoelectric patches and air conduction microphones, and the processor can perform weighting operations on multiple frequency output signals to determine touch occurrences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If capacitive touch sensors are used, then touch sensing capability is provided, but false touch rate increases due to interference from liquids
Solution Approach 1:
The patent replaces capacitive sensing (electrical field-based) with acoustic vibration sensing. A vibration element generates acoustic waves that propagate through the housing, and a receiving element detects vibrations caused by touch operations. This mechanical/acoustic substitution eliminates sensitivity to liquid interference while maintaining touch detection capability.
Solution Approach 2:
The patent introduces acoustic waves as an intermediary medium between the touch operation and the sensing element. The vibration element generates acoustic waves that travel through the housing, and touch operations modulate these waves. The receiving element detects the modulated acoustic signals, providing indirect but reliable touch detection that is immune to liquid interference.
2Reliability
If piezoresistive touch sensors are used, then touch sensing capability is provided, but measurement accuracy decreases due to temperature changes
Solution Approach 1:
The patent replaces piezoresistive sensing (electrical resistance-based) with acoustic vibration sensing. The vibration element generates acoustic waves through the housing, and touch operations create characteristic vibration patterns that are detected by the receiving element. This substitution eliminates temperature-dependent resistance changes while maintaining accurate touch detection through acoustic signal analysis.
3Reliability
If compressive touch sensors are used, then touch sensing capability is provided, but device complexity increases due to high rigidity requirements
Solution Approach 1:
The patent replaces compressive force sensing with acoustic vibration sensing. The vibration element generates acoustic waves that propagate through the housing structure, and touch operations modulate these waves. The receiving element detects the modulated signals, enabling touch detection without requiring high housing rigidity or complex mechanical force measurement systems.
4Reliability
If compressive touch sensors are used, then touch sensing capability is provided, but ease of operation decreases due to large pressing force requirements
Solution Approach 1:
The patent replaces direct compressive force measurement with acoustic vibration detection. The vibration element generates acoustic waves through the housing, and even light touch operations create detectable modulation patterns in these waves. This substitution enables sensitive touch detection with minimal user force, greatly improving ease of operation.
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 touch sensor device effectively recognizes touch operations with high sensitivity, reducing interference from external factors such as liquids, temperature changes, and housing stiffness, while allowing for various touch operations like sliding and pressing.
Implementation Method 1
a signal transmitting unit, configured to generate a vibration signal under the action of an excitation signal; the signal transmitting unit may include a piezoelectric patch
Implementation Method 2
a signal receiving unit, configured to receive the vibration signal and generate an output signal; The air conduction microphone may include a diaphragm
Data Source
AI summary
The embodiments of the present disclosure provide a touch sensor device. The touch sensor device comprises a housing, configured to provide a touch region; and at least one sensor, configured to be fixed near the touch region. The at least one sensor includes: a signal transmitting unit, configured to generate a vibration signal under the action of an excitation signal; a signal receiving unit, configured to receive the vibration signal and generate an output signal; and a processor, configured to recognize a touch operation performed on the touch region according to the output signal.