| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that the height of an optical deflector is hardly reduced because a sufficient length of a herring bone groove in axial direction must be given to generate sufficient dynamic pressure by the rotation of a rotating body in a radial dynamic pressure bearing used in an optical deflector in which the herring bone is commonly formed, which sucks air from vertical direction to a fixed shaft or a rotating shaft. SOLUTION: The optical deflector has: the rotating shaft rotatably mounted inside the fixed shaft; a flange fixed on the rotating shaft so as to surround the fixed shaft; a magnet fixed on the inner peripheral face of the flange; a coil fixed on the outer peripheral face of the fixed shaft at a position to face to the magnet; and a polygon mirror fixed on the rotating shaft or the flange, wherein a groove is provided at least either on the inner peripheral face of the fixed shaft or the outer peripheral face of the rotating shaft to generate dynamic pressure to suck air in one direction, and a space having an opening on the bottom end is provided in the rotating shaft is provided. COPYRIGHT: (C)2008,JPO&INPIT |
