| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a pinch detecting device capable of detecting a pinch without confusing a noise signal generated by a phenomenon different from the pinch with being generated by the pinch. <P>SOLUTION: This pinch detecting device detects that an object is pinched by an opening-closing device on the basis of a frequency of output W1 of a piezoelectric sensor outputting voltage corresponding to mechanical external force. This device has a conversion means 3 binarizing the output W1 of the piezoelectric sensor with the amplitude center as reference voltage ref, a determining means determining the frequency of the output W1 of the piezoelectric sensor by the reference voltage ref and a duration of one value of a binarized signal W2 and determining whether or not this frequency is a lower frequency than a predetermined frequency for detecting the pinch, and a low frequency detecting means 5 detecting low frequency noise of the lower frequency than the predetermined frequency from the output of the piezoelectric sensor. The reference voltage ref is varied by following a detecting result of the low frequency detecting means 5. <P>COPYRIGHT: (C)2007,JPO&INPIT |
