| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact zoom lens having a variable power ratio of 4.5 times or larger, while the half angle of view at the edge of a sufficiently wide angle is 35°or larger, and capable of obtaining the resolving power, coping an imaging device of 3 to 5 million pixels. SOLUTION: The zoom lens satisfies 0.70<Y' max/fw<1.00, where fw is a focal length of all systems at the edge of a wide angle, and Y' max is the maximum image height. A second lens group I is composed of a negative lens L1 whose surface having the larger curvature faces the image side, a positive lens L2 whose surface having the larger curvature faces the image side, and a negative lens L3 whose surface having the larger curvature faces the object side, which are arranged successively from the object side with air space in between. The surface of the negative lens L6 of the closest second lens group II to the image is of aspheric shape, in which the negative refractive power becomes weaker as going farther away from the optical axis. COPYRIGHT: (C)2006,JPO&NCIPI
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