Being laid out on the optical path with not yet joint method of detection of the power source common

摘要

PROBLEM TO BE SOLVED: To detect disconnect state of a plurality of light receiving elements to a power source common terminal.;SOLUTION: This method includes a first step to create a phase A signal of which signal level is reversed every 180 degrees from the light receiving output of the light receiving element, a phase B signal of which signal level is reversed every 180 degrees with 90 degree phase shift in an electrical angle from the phase A, and a reference phase signal of which signal level is reversed every 180 degrees and which is reversed on the rising side at the timing when the signal levels of the A-phase signal and the phase B signal are zero, respectively, and a second step to determine whether or not the power source common terminal is disconnected based on at least the phase A, phase B, and reference phase signal levels created in the first step.;COPYRIGHT: (C)2009,JPO&INPIT