Patent ID: 7061234

Claim:
A modular proximity sensor comprising: a modular head portion containing a detecting coil; a modular preamplifier portion having an oscillating circuit and a supporting member for supporting the modular preamplifier in a fixed position; a modular amplifier portion having a processing circuit; a first cable for connecting the modular head portion and the modular preamplifier portion; and a second cable for connecting the modular preamplifier portion and the modular amplifier portion, wherein the oscillating circuit of the modular preamplifier portion is connected to the detecting coil of the modular head portion via the first cable, and oscillates the detecting coil as a resonance circuit element to affect upon oscillation continuation and suspension, oscillation amplitude, or oscillation frequency, the modular preamplifier portion outputs oscillation output of the oscillating circuit, or output of detected oscillation output via the second cable to the modular amplifier portion, and the processing circuit of the modular amplifier portion detects the presence or absence of an object or the distance from an object, on the basis of the output taken via the second cable from the modular preamplifier portion.