| 摘要 |
PROBLEM TO BE SOLVED: To determine which of a rotation control method at a scanning period of light or a motor has abnormality after switching to the state that the rotation of a polygon mirror is controlled by detecting the light reflected on the polygon mirror. SOLUTION: After the instruction signal FGSEL of Low is output from a CPU 702, when an SOS signal from an SOS sensor 524 is not normally output, a High signal is not output from a one-shot circuit 555 and the output of an OR circuit 558 is turned to High. When the output of the OR circuit 558 is High in a next fixed time interval (a first term) after a fixed time elapses after the instruction signal FGSEL is turned to Low, the CPU 702 detects the light reflected on the polygon mirror and determines that the polygon motor 550 is not rotated normally due to the occurrence of the abnormity when switching to the method for controlling the rotation of the polygon mirror and stops the operation of the polygon motor 550. COPYRIGHT: (C)2010,JPO&INPIT |
