| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem in which: an FG signal includes noise in its detection waveform when a driving current is supplied to a driving motor, and the frequency of the FG signal cannot be accurately detected.SOLUTION: In a state where a driving current is supplied to a driving motor, a driving device of a rotary polygon mirror stops the supply of the driving current or decreases the output of the driving current, and in a state where the driving current is stopped, detects a frequency of an FG signal on the basis of a detection waveform output from a detection element. |
