| 摘要 |
PROBLEM TO BE SOLVED: To provide a capacitance detector for stably performing potential measurement of a reference capacitance by a simple structure while employing a detection circuit of a series circuit type. SOLUTION: This detector is equipped with a first switch S1 disposed across a reference capacitance Cs connected to a potential source V1, a second switch S2 disposed between a capacitance Cx1 to be measured connected to a potential source V2 and the reference capacitance Cs, and a third switch S3 disposed across the capacitance Cx1. After performing a first switch operation in which the first switch S1 is brought into a closed state and then returned to an open state, second and third switch operations are alternately repeated in which the second or third switch S2 or S3 is brought into a closed state and then returned to an open state. A change in the capacitance value of the capacitance Cx1 is determined based on the number of repetitions of the second switch operation repeated until the potential of the other end T2 of the reference capacitance Cs has changed from an initial potential V1 to a set potential after the first switch operation. COPYRIGHT: (C)2005,JPO&NCIPI
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