| 摘要 |
PURPOSE:To improve manual focusing operability and to prevent application of a large load on a motor and other parts at the time of autofocusing by providing an operating ring which engages selectively with either of a focusing mechanism or zoom mechanism on a lens barrel. CONSTITUTION:The operating ring 27 is engaged with a focus actuating cylinder 22 via a steel ball 33 and a groove 36 while the ring 27 is held set forward. A focusing lens group 10 moves forward and backward in the optical axis direction and manual focusing is feasible when the ring 27 is rotated. The steel ball 34 engages with the groove 37 of an actuating cylinder 21 when the ring 27 is moved backward and, therefore, the zoom lens groups 9a, 9b are moved forward and backward in the optical axis direction and zooming is executed by rotating the ring 27. The ring 27 and the cylinder 22 are held disconnected at this time and consequently, even if the focusing mechanism is actuated by the motor for autofocusing, the motion thereof is not transmitted to the ring 27.
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