| 摘要 |
PURPOSE:To perform zooming operation and focusing in a macro-photography range speedily and smoothly by providing a common-use moving lens frame which is movable in an optical-axis direction with a cam surface for the macro- photography range for focus adjustment in the macro-photography range. CONSTITUTION:When an operation knob 11 is rotated for normal zoom photography while the projection 12 of a rotating knob 9 is inserted into a small hole 7a, a cam cylinder 2 rotates together with a zoom operation ring 5, and consequently a front-group moving lens frame 22 and a rear-group moving lens frame 18 move simultaneously to vary the power. When a subject in the macro-photography range beyond the normal closest distance wherein zoom photography is possible, the rotating knob 9 is lifted and rotated to move a guide plate to left, and an engagement pin 17 abuts on the cam surface 18a for the macro-photography range 18a formed on the rear-group moving lens frame 18; and the rear- group moving lens frame 18 is moved to left independently of the front-group moving lens frame 20 to perform focusing operation in the macro-photography range. |
