| 摘要 |
PROBLEM TO BE SOLVED: To reduce the time required for speed reduction or stopping of a rotating polygon mirror, rotating in a dynamic pressure air bearing type optical deflector. SOLUTION: The optical deflector 3 includes: a dynamic pressure shaft 71 having exhaust holes 71g, 71b, 71c; a sleeve 72, freely rotatably supported by a dynamic pressure air bearing part M on the dynamic pressure shaft 71; a rotating polygon mirror 2 rotating integrally with the sleeve 72; and a sealed mirror room 70 which houses the sleeve 72 and the rotary polygon mirror 2; and an air chamber 90, which communicates to the mirror room 70 via the exhaust holes 71g, 71b, 71c and shuts off the ambient air. When the sleeve 72 is accelerated and rotated by a motor 88, the air in the mirror chamber 70 is exhausted to the air chamber 90 via the exhaust holes 71g, 71b, 71c, the mirror chamber 70 is depressurized. COPYRIGHT: (C)2010,JPO&INPIT |
