| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens reduced in size as a whole while having a high zooming ratio, and an imaging apparatus. SOLUTION: A first lens group G1 with positive power, a second lens group G2 with negative power, a stop St, a third lens group G3 with positive power, and a fourth lens group G4 with positive power are arranged in this order. Zooming is performed by moving at least the first lens group G1, the second lens group G2, the stop St and the third lens group G3 along an optical axis Z1. During zooming, the stop St is moved to be closer to an image plane at a wide-angle end than at a telephoto end and to be closer to the second lens group G2 at the telephoto end than at the wide-angle end. The following conditional expressions are satisfied: 4.0<f1/fw<7.0 ... (1) and 0.2<X1/ft<0.3 ... (2), wherein fw is a focal length at the wide-angle end of the entire system, ft is a focal length at the telephoto end of the entire system, f1 is a composite focal length of the first lens group, and X1 is a displacement of the first lens group G1 during zooming from the wide-angle end to the telephoto end. COPYRIGHT: (C)2010,JPO&INPIT |
