ROTATING BODY SPEED DETECTION DEVICE AND IMAGE FORMING DEVICE

摘要

PROBLEM TO BE SOLVED: To detect a machine datum of an encoder wheel without increasing cost.;SOLUTION: Two detection sensors are arranged facing each other with respect to a rotation center of an encoder wheel which is connected to a rotation axis of a rotating body and having a lattice-shaped pattern formed along a circumferential direction. When the detection sensors detect a rotation speed of the rotating body, comparators 301-3 and 302-3 detect output rising edges of the two sensors, respectively to obtain first and second edge signals. A determination circuit determines which of the first and second edge signals precedes, to obtain a determination result. A generation circuit generates a datum detection signal indicating a machine datum of the encoder wheel when the detected order of precedence changes.;COPYRIGHT: (C)2013,JPO&INPIT