| 摘要 |
PROBLEM TO BE SOLVED: To provide a deflection scanning apparatus in which the occurrence of uncomfortable noise is suppressed at the conversion of the number of rotation of a rotating polygonal mirror. SOLUTION: During the period of time when the rotating polygonal mirror 5 repeats overshoots and undershoots of the number of rotation immediately after reaching the predetermined number of rotation, a torque control acceleration mode and a torque control braking mode which reduces the deflection scanning speed of the rotating polygonal mirror by reducing the electric current supplied to the driving phase coil of a motor, are repeated in a translational response manner to converge the the number of rotation. In a speed reduction time, only reduction in electric current supply to a coil is performed by using the torque control braking mode, thus, a rapid speed reduction does not take place, the vibration of the coil is low and sound of a frequency not lower than the stationary number of rotation does not occur. COPYRIGHT: (C)2006,JPO&NCIPI |
