| 摘要 |
PURPOSE:To eliminate the adverse influence of dirt upon picture representing performance owing to the sticking of dust on a polygon mirror in operation by providing a scanner motor with a cover made of general resin. CONSTITUTION:A polygon mirror 19 is fixed on the rotor of the scanner motor 18. A holder 25 clamps and holds optical path formation glass 26 made of optical glass and is fitted and elastically mounted in a holder cut part 27b that the cover 27 has and right and left, and upper grooves 27a. The cover 27 and holder 25 are both made of general resin, e.g. polypropylene. The cover 27 has a screw hole 27d and is clamped and fixed to the screw hole 18b of a fitting flange part 18a with a setscrew 28. The cover 27, holder 25, and glass 26 constitute the dust-protective structure of the polygon mirror 19. The thickness of the holder 25 is selected so that a bare hand in not able to touch the glass 26 even when the window part of the holder 25 is picked up with fingers. |
