| 摘要 |
PROBLEM TO BE SOLVED: To simplify and miniaturize the driving part of a rotary polygon mirror. SOLUTION: The rotary polygon mirror 1 is pressed against the reference surface 4b of a flange member 4 by a pressure member 6 which is fixed on the projecting part 4a of the flange member 4 by screwing, then, the rotary polygon mirror 1 is integrally connected to a rotor magnet 5 through the flange member 4. The pressure member 6 functions also as a cover member for forming an air reservoir 10 above the upper end of a bearing gap between the rotary sleeve 3 and a fixed shaft 2, then, it is unnecessitated to project the rotary sleeve 3 and the fixed shaft 2 above the rotary polygon mirror 1. |
