| 摘要 |
PURPOSE: To enhance stability in a thrust bearing of a rotary polygon mirror. CONSTITUTION: The rotary polygon mirror 1 is integrated with a rotary sleeve 3, and the rotary polygon mirror 1 is rotated integrally with a rotary magnet 4 when a stator coil is energized. A first permanent magnet 9a stuck to the bottom end of the rotary sleeve 3 is arranged on the inside of a second permanent magnet 9b integrated with a motor housing 6 and confronted with the inner peripheral surface. Both permanent magnets 9a, 9b are magnetized to polarities opposite to each other in the axial direction, and pressing force acting so as to make the magnetic central positions coincide with each other occurs between both magnets, and it functions as the thrust bearing stably fixing the position of the rotary sleeve 3 in the axial direction. |
