| 摘要 |
A capacitance sensor usable as a fingerprint sensor is provided in which a timing controller ( 16 ) provides such a switching control as to first cause a switch (SA) in a sensor cell ( 100 -k) to turn on to set the potential at a sense electrode to a reference potential and then a switch SB to turn on after the switch (SA) is turned off, whereby charge is stored from the sensor cell ( 100 -k) into a reference capacitance Cf 1 of a sensing circuit ( 13 -k), the sensitivity of sensing the capacitance is raised by increasing the number of times the charge storage is repeated and only signal components are extracted by reducing noise components by averaging.
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