| 摘要 |
A zoom lens comprising, from front to rear, a first lens group of positive power movable for focusing, second and third lens groups of negative power movable for zooming, and a fourth lens group stationary during focusing and zooming. When zooming is performed from the wide angle to the telephoto setting, the aforesaid second lens group is axially moved in a one-directional manner toward the image plane, while the aforesaid third lens group is axially moved in a reciprocating manner toward the object. With this type zoom lens, a compact structure is realized by positioning the rear principal plane of the aforesaid first lens group as near the image side as possible and the rear principal plane of the aforesaid second lens group as near the object side as possible.
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