| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens which is small, thin, and with high optical performance, thereby being suitable for a mobile camera. SOLUTION: The zoom lens includes: a negative first lens group I, which transfers toward the image surface side, and on its way, transfers to the object side by reversing; and a positive second lens group II which transfers to the object side, wherein the first lens group comprises the negative first lens of meniscus shape in which the convex face faces the object side, and the positive second lens. When the thickness of the first lens group is DG1, the thickness of the second lens group is DG2, the air interval between the first lens and the second lens is D2, the focal length of a lens system at the wide angle end is fw, the focal length of the first lens group is fG1, and the focal length of the second lens group is fG2, 0.90≤(DG1+DG2)/fw≤2.30, 0.5≤¾fG1¾/fG2≤1.6, 0.10≤D2/fw≤0.35, and 1.5≤¾fG1¾/fw≤2.5 are satisfied. Thus, power arrangement of the first lens group and the second lens group is appropriately set, and miniaturization, and thickness reduction are achieved while securing variable power ratio of about three time. COPYRIGHT: (C)2011,JPO&INPIT
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