Patent ID: 8593430

Claim:
A device for processing capacitance of a plurality of layers of a multi-touch panel, wherein each layer of the multi-touch panel has a plurality of sensors, comprising: a plurality of capacitance processing units, each of which being coupled with a plurality of sensors of a respective layer of the multi-touch panel such that each of the capacitance processing unit scans to capture capacitance values detected by the respective sensors of the corresponding layer when the multi-touch panel is touched at multiple positions, and then processes the captured capacitance values, wherein the detected capacitance value is the summation of an intrinsic capacitance value of the corresponding layer and a capacitance variation of the corresponding layer, the intrinsic capacitance value is formed between a surface of the sensor and a surface of the panel, the capacitance variation is a result of the touch on the sensor of the corresponding layer, and wherein each capacitance processing unit processes the captured capacitance values of each layer by eliminating the intrinsic capacitance value such that the processed capacitance values comprises mainly the capacitance variation; a plurality of capacitance converting units, each of which being correspondingly coupled with one of the capacitance processing units for converting the capacitance values processed by the capacitance processing unit into respective digital capacitance parameter outputs; and an analyzing and processing unit for analyzing and processing the digital capacitance parameter outputs in order to determine multiple touch positions on the multi-touch panel, wherein the capacitance values of each layer of the multi-touch panel is processed independently, such that the capacitance values of each layer are compensated separately when the panel is touched.