Surface Capacitive
Sensor Materials
Glass substrate, transparent metal oxide coating
Principle of Operation
- Voltage is applied to the corners of the touch screen.
- A pattern of electrodes around the periphery of the touch screen distribute the voltage to form a uniform electric field across the conductive surface.
- A finger touch draws a minute amount of current from the surface and is measured by the controller.
- The relative magnitude of current is inversely proportionate to the distance from the contact point to the touch screen corners.
- Ratios of the four corner currents are calculated to determine the X, Y coordinate.
Pros and Cons
Pros | Cons |
Withstands contaminants and moving liquids on the screen and keeps working across the entire touchscreen surface | Supports only finger or tethered pen |
Very light finger touch required for activation | Severe scratch can affect operation within the damaged area |
Technology with fastest touch response time | Limited to 1 resolvable point with gesture capability |
Transmission typically 88 % to 9 2% |
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