Patent ID: 6720545
Filing Date: 2004-04-13
Classification: G01J,G01S

Abstract:
A method of controlling a photoelectric sensor, said method comprising the steps of:transmitting pulsed light repetitively by driving a light transmitting element of said photoelectric sensor at a specified light transmission timing; comparing the level of reception signal with a specified first threshold value and thereby judging the level of said reception signal at a level-judging timing which is slightly delayed from said light transmission timing, said reception signal being outputted according to an output from a light receiving element of said photoelectric sensor for receiving light; making a comparison, if said reception signal includes an AC waveform corresponding to noise, between said level of reception signal and a second threshold value proximal to an AC zero level determined from said AC waveform; and controlling the timing of next light transmission from said photoelectric sensor based upon the result of said comparison.