| 摘要 |
PROBLEM TO BE SOLVED: To prevent the deviation of a picture in a subscanning direction smaller than one scanning pitch while the fitting position of the direction of each polygon mirror need not be adjusted correctly or the fitting position of a Hall element, etc., need not be checked beforehand by an experiment or evaluation, etc. SOLUTION: In a light beam scanner provided with four polygon mirrors, a controller 14 which controls each roration reference signal generating part 16(2) to 16(4) so that the setting of each phase difference between a rotation reference signal P1 to be used for the motor driver 12(1) of a reference polygon mirror 9(1) and the rotation reference signal to be used for the motor drivers 12(2) to 12(4) of the other polygon mirrors 9(2) to 9(4) is changed on the basis of setting change data inputted from the outside is provided. |
