Patent ID: 6888536

Claim:
A multi-touch surface apparatus for detecting a spatial arrangement of multiple touch devices on or near the surface of the multi-touch apparatus, comprising: one of a rigid or flexible surface, the surface having, for each hand, a shallow depression running between the default index and pinky fingertip locations to provide tactile indication of fingertip home positions; a plurality of the sensing devices arranged on the surface, each sensing comprising: two electrical switching means connected together in series having a common node, an input node, and an output node, a dielectric-covered sensing electrode connected to the common node between the two switching means, a power supply providing an approximately constant voltage connected to the input node of the series-connected switching means, an integrating capacitor to accumulate charge transferred during multiple consecutive switchings of the series connected switching means, another switching means connected in parallel across the integrating capacitor to deplete its residual charge, and a voltage-to-voltage translation device connected to the output node of the series-connected switching means which produces a voltage representative of the proximity of the touch device to the sensing device; control circuitry for sequentially enabling each of the sensor devices; voltage measurement circuitry to convert sensor data to a digital code; and circuitry for communicating the digital code to another electronic device.