Capacitance change detection circuit, touch panel and determination method

摘要

A detection circuit 1 includes: an input unit 2; two contact electrodes A and B which are connected to the input unit; phase inversion unit 3 connected to the contact electrode A; one amplification unit 41 arranged in each contact unit; and detection units 5A and 5B which detect as an electric change amount, an amplitude change of an input signal caused by a capacitance change in each of the contact electrodes A and B. The detection circuit 1 causes the two electrodes to input signals having phases shifted by a half period from each other by using the phase inversion unit 3. In the presence of contact, the amplitude of the input pulses is amplified by the one amplification unit 41. The respective detection units 5A and 5B detect signals of respective electrodes from the one amplified signal and output them to output units 6A and 6B, respectively.