Patent ID: 7719522

Claim:
A track pad input device comprising: a capacitive track pad sensor having a plurality of sensing elements, each sensing element associated with a region of the capacitive track pad sensor; means for measuring and selectively encoding a digital capacitance value for each of the plurality of sensing elements, the digital capacitance value representing a raw capacitance measurement of the sensing element; and means for transmitting the plurality of digital capacitance values to a host processor for processing, wherein the digital capacitance values are aggregated into packets and transmitted according to a universal serial bus protocol, and the host processor is also at least partially responsible for executing user-level tasks, wherein the track pad sensor comprises a capacitive sensor array, and the means for measuring comprises means for selectively stimulating each of the plurality of sensing elements, means for determining a time required to stimulate each selected sensing element to a specified event, and means for encoding the determined time into a digital value.