Patent attributes
A device for combined capacitance and pressure measurements includes a plurality of first input/output terminals for a projected capacitance touch panel wherein the projected capacitance touch panel includes a layer of piezoelectric material disposed between a plurality of sensing electrodes and a common electrode. The device also includes a plurality of second input/output terminals for a capacitive touch controller. The device also includes a plurality of separation stages, each separation stage connecting one first input/output terminal to a corresponding second input/output terminal, and each separation stage includes a first frequency-dependent filter for filtering signals between respective first and second input/output terminals. The device also includes at least one amplification stage, each amplification stage having at least one input and an output configured to provide an amplified signal, wherein the number of amplification stages is less than or equal to the number of separation stages and each amplification stage input is connected to one or more of the first input/output terminals through the respective separation stage(s) Each amplification stage or each separation stage includes a second frequency-dependent filter for filtering signals between the respective first input/output terminal and an amplification stage input. Each first frequency-dependent filter is configured to pass signals from the capacitive touch controller and each second frequency-dependent filter is configured to attenuate signals from the capacitive touch controller.
