| 摘要 |
PROBLEM TO BE SOLVED: To further miniaturize a zoom lens for use in digital image photographing while maintaining a high performance thereof. SOLUTION: The zoom lens has a first group I which is arranged on the object side and has a negative focal length, a second group II which is arranged on the image side of the first group and has a positive focal length, and a stop S which moves to the object side of the second group together with the second group as as a single body. When the power is varied from a short focus end to a long focus end, the second group moves monotonously from the image side to the object side, and the first group moves so as to compensate the variance of an image surface position due to power variation. A variable magnification group which is constituted as the second group and practically varies the power is constituted of three lenses, that is, a positive lens of which the surface of higher curvature is directed to the object side, a negative lens of which the surface of higher curvature is directed to the image side, and a positive lens. The surface nearest to the object and the surface nearest to the image are aspherical. COPYRIGHT: (C)2004,JPO
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