Synaptics Incorporated
Sensing for touch and force

Abstract:

An input device described herein includes at least one dual purpose electrode that is used to perform both capacitive sensing to detect an input object (e.g., a finger or stylus) and force sensing to determine the force applied by the input object on the input device. During a first time period, the input device performs capacitive sensing using a first electrode of the plurality of sensor electrodes. However, during a second time period, the input device excites the first electrode and measures a resistance corresponding to the first electrode. The input device determines a force applied by an input object on the input device based on the measured resistance.