| 摘要 |
PURPOSE:To reduce the size and weight of the whole lens barrel by providing both transmission shafts which are sectioned almost circularly in contact with each other in parallel to an optical axis so that they are integrated together in a rotating direction and separated in optical-axis directions. CONSTITUTION:A gear 14 for lens movement engages a driving gear 12 through an auxiliary frame 13, so the 2nd transmission shaft 10B slides and moves to and away from the 1st transmission shaft 10A while rotating as a focus lens group frame 18 moves back and forth, thereby performing focusing operation by the movement of the (I)th group lens. Then when a zoom frame 2 is rotated from the wide-angle side to the telephoto side, a cam cylinder 15 is rotated by a pin 22. In this case, the pin which supports the (I)th lens group and the (III)th lens group is controlled by the cam cylinder 15 and a straight moving groove cylinder 16, so both lens groups move back and forth while rotating according to the rotation of the cam cylinder 15. Then, the 2nd transmission shaft slides to and away from the 1st transmission shaft to perform zooming operation. Thus, the lens barrel is reduced in size and weight on the whole. |
