| 摘要 |
PURPOSE:To improve the precision of light beam scanning by attaching a rotary polygonal mirror body to a motor shaft so that a specular surface from which the distance to the center of the rotary polygonal mirror is shortest is matched to a motor shaft angular position where the extent of shake is maximum. CONSTITUTION:After a motor 10 is set, it is driven, and an optomicrometer 13 measures a length L to the peripheral surface of a motor shaft 10a, and the motor shaft 10a is irradiated with a synchronous strobe lamp 15. Consequently, the length L is measured in each angular position of the motor shaft 10a to detect the direction in which and degrees by which a position X where the extent of the shake of the motor shaft 10a is maximum is deviated from a reference mark M. By the similar method, a mark (m) is added to a position corresponding to a specular surface 16a to which the length from the center of a rotary polygonal mirror body 16 is shortest. The rotary polygonal mirror body is attached to the motor shaft so that the mark (m) is matched to the position where the extent of shake of the motor shaft 10a is maximum. Thus, the precision of light beam scanning is improved. |
