PURPOSE: To speed up restoration from disturbance by providing a face inclination variable detecting means for respective reflecting surfaces of the polygon mirror, a means for storing respective face inclination variables in each reflecting surface and a means for correcting the face inclination variable read out from the storing means in a light deflecting device for deflecting light projected from a light source by a rotary polygon mirror.
CONSTITUTION: A face inclination variable detector 5 consisting of a CCD line sensor is driven by clock pulses generated from a clock generator 21 connected to a counter 22 and an obtained detection signal is compared with a reference level VS1 by a comparator 23. The compared signal is applied to a storage device consisting of memories 31W35 connected in series through a latch circuit 24 and a contact (a) of a change-over switch 30 and the final memory 35 is connected to a contact (b) of the switch 30 and also connected to a D/A converter 25 through a switch 36. The output of the converter 25 is applied to a correcting mechanism driving device 11 through a comparator 26 having a reference level VS2 and an amplifier 27. If it is unnecessary to store data, a storage circuit is removed by using the switch 30.
SUZUKI SEISUKE
YUI KOJI
SHIROKURA AKIRA
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