| 摘要 |
<P>PROBLEM TO BE SOLVED: To make it possible to adjust an offset at accuracy higher than the minimum value of an adjusting capacitive element. <P>SOLUTION: In a capacitance detecting device (10) including an offset adjusting circuit (14) which removes an offset from charge transferred from a charge reading mechanism (12) to an integrator (13), the offset adjusting circuit (14) includes: a variable capacitive element (21) which consists of a plurality of capacitive elements and is set to a predetermined capacitance value by switching the number of capacitive elements parallelly connected to a charge transfer line; and an adjusting capacitive element (23) which is parallelly connected to the variable capacitive element (21) and has the minimum value of capacitive elements that constitute the variable capacitive element (21), in which drive control is performed such that the adjusting capacitive element (23) repeatedly removes an offset for N times while the variable capacitive element (21) repeatedly removes an offset for M times (M>N; M and N are natural numbers). <P>COPYRIGHT: (C)2012,JPO&INPIT |
