Patent ID: 6825962
Filing Date: 2004-11-30
Classification: G02B

Abstract:
A scanner comprising:a light-beam emitter for emitting a light beam; a light-beam deflector for deflecting said light beam to scan a scanning surface; a photo-detector provided at a position outside an image-forming scanning range of said scanning surface to detect a scanning light beam before said scanning light beam starts generating a scanning line in said image-forming scanning range; a rotatable member located in front of an incident surface of said photo-detector, said rotatable member being rotatable about a rotational axis perpendicular to a plane defined by said scanning light beam by said deflector; an optical member that is provided on said rotatable member, said optical member allowing said scanning light beam to pass therethrough to be incident upon said incident surface of said photo-detector; a device for rotating said rotatable member about said rotational axis, said device comprising a circumferential gear formed on an outer peripheral surface of said rotatable member and a rotating tool engageable with said rotatable member to rotate said rotatable member about said rotational axis, said rotating tool comprising a pinon gear which is engaged with said circumferential gear.