| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact zoom lens system which has a high-speed auto-focus function wherein a maximum half angle of view is about 3.3°at its telephoto end, has an image blur-correction function, and has excellent imaging characteristics, and to provide a camera system. SOLUTION: The zoom lens system has, from an object side to an image side, a first lens group having positive power, a second lens group having negative power, a third lens group having negative power, a fourth lens group having positive power, and a fifth lens group having negative power, and has an aperture diaphragm via an air space which does not change in zooming on the image side of the third lens group. The zoom lens system changes, in zooming, the spaces between the respective lens groups so that the air space between the first and second lens groups may be larger at its telephoto end than at the wide angle end, the space between the third and fourth lens groups may be shorter at its telephoto end than at the wide angle end, and the space between the fourth and fifth lens groups may be shorter at its telephoto end than at the wide angle end, while in focusing, the system moves the fifth lens groups along the optical axis. The system also moves in parallel, in image blur-correction, the third lens group in the direction perpendicular to the optical axis. The camera system using the zoom lens system is also provided. COPYRIGHT: (C)2009,JPO&INPIT
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