| 摘要 |
PURPOSE:To prolong the life of an air dynamic pressure bearing type light deflector setting a rotary member containing a rotary polygon mirror at a non-vertical attitude. CONSTITUTION:A dynamic pressure air bearing is provided on the bearing of a drive mechanism of the rotary member 1 having the rotary polygon mirror 11, and when the air dynamic pressure bearing is in a state other than a vertical attitude, a center axis Y-Y in the horizontal direction of a stator core 7 is made eccentric by DELTAd downward in the vertical direction for the center axis X-X in the horizontal direction of the rotary member 1 by an amt. canceling force corresponding to gravity of the rotary member 1 expressed in terms of an axis inclination angle in the vertical direction and magnetic unbalance force generating eccentricity between a rotary magnet 6 and the stator core 7. Thus, contact force and contact time on the bearing are reduced and the wear in the bearing is reduced. |
