| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a capacitance type switch device a noise countermeasure for which can be achieved with a simple circuit and electrode configuration. <P>SOLUTION: Adjacent capacitance type switches are alternately connected to an input plus terminal and an input minus terminal of a differential amplifier 10. In this situation, even if the respective capacitance type switches are affected by exogenous noises and consequently output noise signals, the differential amplifier 10 can reject the noise signals and only detection signal output from the capacitance type switches for performing the detection can be detected. Therefore, a detection accuracy of the capacitance type switch is improved and an accurate stroke position of an electronic keyboard instrument can be detected. Consequently, since the noise signals caused by the exogenous noises can be rejected only by using the differential amplifier 10, a noise rejection device can be configured easily and the noise counter measure can be achieved inexpensively. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
