| 摘要 |
PROBLEM TO BE SOLVED: To avoid the breakage of a circuit element due to high electrostatic voltage without increasing a cost, and moreover to detect a proximity object with the high accuracy without causing a malfunction due to transmission/reception by a cellular phone etc. SOLUTION: In an electrostatic capacity type proximity sensor, a base of a transistor Q1 of an oscillation circuit 1 is connected to a detection electrode DP. A periphery excluding a detection face of the detection electrode DP is surrounded by a grounding electrode SP, which is connected to a grounding GND of a circuit. Further, a capacitor C3 for canceling a floating capacity between the detection electrode DP and the earth is parallel-connected to a feedback bias resistor R1. COPYRIGHT: (C)2006,JPO&NCIPI
|
