| 摘要 |
PURPOSE:To accurately position a movable lens, to make the variably magnifying device compact, and to reduce costs by providing a cam part on a turning body, which is turnably supported by means of a lens bracket so that it is perpendicular to the optical axis of a lens unit, and engaging the cam part with a movable shell. CONSTITUTION:At the time of copying under unmagnification, the one end 17a of a shutter 17 is detected by a home position sensor 18, the turning body 11 is stopped in a home position, and the movable lenses 8A and 8B are positioned so that they are farthest apart from each other. On the other hand, at the time of changing a copying magnification, an amount of the movement of the movable lenses 8A and 8B and an amount of the movement of the entire lens unit 4 are calculated based on variable power conditions and the detecting information of the home position sensor 18, so that a driving motor 14 is driven. Since the cam groove parts 1b and 11c of the turning body 11 are engaged with pins 12A and 12B fixed to movable shells 7A and 7B, the movable lenses 8A and 8B are moved toward each other to be positioned, when the turning body 11 is turned via a peripheral gear part 11d by means of the rotation of the driving motor 14. |
