Tactile Interface Surface Variations Acoustic Touch Detection
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Solution Overview
Problem
Existing touch-sensitive devices face inaccuracies and high costs due to reliance on capacitive sensing, which is ineffective for gloved or dirty fingers and conductive materials, and may require incompatible device sizes and shapes.
Innovation Solution
A touch-sensitive device with a tactile interface featuring surface variations that produce energy signatures, detected by electro-mechanical transducers and processed by a controller to generate control signals, allowing for accurate tactile interaction detection regardless of surface material or user input.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If capacitive sensing is used to detect touch, then the device can sense touch based on capacitance change, but the sensing becomes inaccurate for gloved or dirty fingers and conductive materials
Solution Approach 1:
The patent replaces capacitive sensing (electrical field-based) with acoustic sensing using a microphone to detect vibrations and impacts on the surface. This mechanical/acoustic approach is not affected by the electrical properties of the touching object, making it work reliably with gloved fingers, dirty fingers, and conductive materials that fail capacitive sensing.
Solution Approach 2:
The patent changes the detection parameter from electrical capacitance to acoustic vibrations and impact sounds. By detecting the physical vibrations and acoustic signatures produced when different objects touch the surface, the system achieves reliable detection across various finger conditions and materials without being constrained by electrical conductivity requirements.
2Measurement precision
If capacitive sensing is used to achieve sufficient resolution, then touch detection is possible, but the implementation cost becomes expensive
Solution Approach 1:
The patent replaces expensive capacitive sensing arrays required for high-resolution touch detection with a single or few acoustic sensors (microphones). The acoustic approach captures vibration and impact information that naturally provides spatial and tactile resolution without requiring dense sensor arrays, significantly reducing component count and implementation cost.
Solution Approach 2:
The patent makes a single acoustic sensor perform multiple functions: detecting touch location, identifying finger vs. stylus, recognizing writing gestures, and determining pressure levels. This multi-functionality eliminates the need for multiple specialized sensors, reducing overall system cost while maintaining comprehensive tactile detection capabilities.
3Reliability
If capacitive sensing is used, then touch detection works for standard surfaces, but it becomes ineffective for conductive materials such as metal
Solution Approach 1:
The patent substitutes electrical field-based capacitive sensing with acoustic field-based detection. Since acoustic vibrations and impacts are independent of the electrical conductivity of the surface or touching object, the system works equally well on conductive materials like metal, non-conductive plastics, and other surfaces regardless of their electrical properties.
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
This solution enables accurate and cost-effective detection of tactile interactions across various surfaces, including conductive metals and non-conductive plastics, with a single transducer capable of distinguishing different inputs, such as fingertips and styluses, improving performance and reducing implementation costs.
Implementation Method 1
an electro-mechanical transducer configured to generate an electrical output signal in response to detecting the energy signature
Data Source
AI summary
Disclosed herein are related to a touch sensitive device. The touch sensitive device includes a panel with a surface including a tactile interface, where the tactile interface has surface variations forming a tactile pattern. In one aspect, tactile interaction with the tactile pattern produces an energy signature representative of the surface variations. In one aspect, the touch sensitive device further includes an electro-mechanical transducer configured to generate an electrical output signal in response to detecting the energy signature. In one aspect, an output of the electro-mechanical transducer is connectable to a processor configured to produce a control signal based on the electrical output signal of the electro-mechanical transducer.