| 摘要 |
PROBLEM TO BE SOLVED: To obtain a good detection results with high sensitivity with simple constitution. SOLUTION: The detection process circuit 14 for obtaining various information about an object to be detected by properly processing the DC conversion signal DC converted from the sinusoidal detection output from the detection coil 12 is constituted such that a signal variation of the DC conversion signal is detected by differentiating the DC conversion signal by the differential circuit 17, and the various information about the object is obtained based on the variation of the DC conversion signal. By the constitution, so called effect of temperature drift can be eliminated, lowering the threshold value for detection can be made possible, and the detection distance can be extended. COPYRIGHT: (C)2005,JPO&NCIPI |
