Patent ID: 8587553
Filing Date: 2013-11-19
Classification: H03K

Abstract:
1. A capacitance change detection circuit, comprising: at least one set of contact electrodes including a set of a first contact electrode supplied with a pulse signal from an input unit for the pulse signal via phase inversion means, and a second contact electrode supplied with the pulse signal from the input unit; a combining connection point that combines a first single output pulse output from the first contact electrode and a second single output pulse, corresponding to the first single output pulse, output from second contact electrode, and outputs a combined output; a single amplification means connected to the combining connection point for amplifying combined output from the combining connection point, the combining connection point being provided between the at least one set of contact electrodes and the single amplification means; first detection means for receiving the amplified combined output from the single amplification means and detecting a signal showing a state of the first contact electrode, the first detection means receiving the pulse signal via the phase inversion means to cancel signal indicative of a state of the second contact electrode; second detection means for receiving the combined output from the single amplification means and detecting a signal showing the state of the second contact electrode, the second detection means receiving the pulse signal from the input unit to cancel signal indicative of the state of the first contact electrode; and output units connected to the first detection means and the second detection means, respectively.