| 摘要 |
PURPOSE:To provide a lens position controller for a zoom lens capable of accurately setting the focal distance at the time of photographing, in the zoom lens having a system that a zoom lens barrel is made compact inside a camera main body and to obtain a collapsible barrel. CONSTITUTION:A lens space between first and second group lenses L1 and L2 which is enequivocally determined by a change in the focal distance, is detected. An optical system noncontact type lens position detecting device composed of a prism 53, a slit plate 53a, and a photodetector 52, is provided on the lens barrel 1, for instance, the zoom positions of 13-stages are set according to the width of a zooming range, in the first/second group lenses L1 and L2, and the position of a third group lens L3 is controlled based on lens position information from the lens position detecting device. Thus, a contribution to the miniaturization of the lens barrel 1 is made, and the lens position control is accurately carried out. |
