| 摘要 |
PURPOSE: To miniaturize a zoom lens and to smoothly perform focusing operation all over the zooming area by making common a mechanism for extending an in-focus lens to perform zooming and a mechanism for extending the in-focus lens to perform focusing. CONSTITUTION: When a zoom operating ring 10 is rotated, a 2nd variable power cam barrel 80 is rotated through a 1st coupling pin 11P, a 3rd lens group 104 is moved and simultaneously a 4th lens group 106 is moved. By the rotation of the cam barrel 80, a 2nd lens group moving frame 90 and a 2nd lens group guiding pin 91P are rotated and moved back and forth by the regulation of a 2nd lens group rotating pin 92P and a 2nd lens group guiding pin 91P engaged in the 2nd cam groove of the 2nd lens group of a straight advance barrel 50. By the rotation of the guiding pin 91P, the pin 91P is moved in the 3rd cam groove of the 2nd lens group, and a part of the 3rd cam groove of the 2nd lens group aligned with a zooming position at that time is used. |
