May 23, 2016
Nowadays several modern devices, such as smartphones and tablets utilize projected capacitive touchscreens, consisting of a touchscreen sensor and a controller. Touchscreen sensors generally consist of two coplanar electrode grids surrounded by dielectrics, while their operation is based on the variation of the mutual capacitance between the electrodes as a finger or generally a conductive object comes close to the touchscreen surface.
This report shows simulation results obtained by Sense, the electrostatic simulation software specially developed by Fieldscale so as to satisfy the requirements of touchscreen sensor designers. By using this simulation tool, touchscreen sensor designers can ensure compatibility between sensor and controller. This is achieved by estimating the mutual capacitance variation for all possible finger positions and comparing these values with controller specifications. In addition, based on simulation results, the settings of the controller can be adjusted through its firmware, so as to be triggered by specific capacitance variations.