| 发明名称 | Zoom lens and imaging apparatus | ||
| 摘要 | A zoom lens includes: a first lens group having a negative power; and a second lens group having a positive power, in this order from an object side. The first lens group includes a first lens having a negative power and a second lens having a positive power. The zoom lens satisfies conditional formulae 1.6<|f1|/fw<2.5 (1); 1.6<f2/fw<2.4 (2); 0.32<d2/fw<0.60 (3); 2.5<ft/fw<4.5 (4); 1.56<nd2<1.66 (5); and νd2<33 (6), when f1: the focal length of the first lens group, f2: the focal length of the second lens group, fw: the focal length of the entire system at the wide angle end, d2: the distance between the first and second lenses along an optical axis, ft: the focal length of the entire system at the telephoto end, nd2: the refractive index of the second lens at the d line, and νd2: the Abbe's number of the second lens at the d line. | ||
| 申请公布号 | US8917454(B2) | 申请公布日期 | 2014.12.23 |
| 申请号 | US201314139252 | 申请日期 | 2013.12.23 |
| 申请人 | FUJIFILM Corporation | 发明人 | Kawamura Daiki |
| 分类号 | G02B15/14;G02B3/02;G02B9/08 | 主分类号 | G02B15/14 |
| 代理机构 | Young & Thompson | 代理人 | Young & Thompson |
| 主权项 | 1. A zoom lens, practically comprising: a first lens group having a negative refractive power; and a second lens group having a positive refractive power, provided in this order from an object side; the first lens group moving along a trajectory which is convex toward an image side, the second lens group moving monotonously toward the object side, and an aperture stop moving integrally with the second lens group when changing magnification from a wide angle end to a telephoto end; the first lens group comprising two lenses, a first lens having a negative refractive power and a second lens having a positive refractive power; at least one of the two lenses of the first lens group being a plastic lens; the second lens group comprising three or fewer lenses, of which at least one is a plastic lens; and the zoom lens satisfying the following conditional formulae: 1.6<|f1|/fw<2.5 (1)1.6<f2/fw<2.4 (2)0.32<d2/fw<0.60 (3)2.5<ft/fw<4.5 (4)1.56<nd2<1.66 (5)νd2<33 (6) wherein f1 is the focal length of the first lens group, f2 is the focal length of the second lens group, fw is the focal length of the entire system at the wide angle end, d2 is the distance between the first lens and the second lens along an optical axis, ft is the focal length of the entire system at the telephoto end, nd2 is the refractive index of the second lens with respect to the d line, and νd2 is the Abbe's number of the second lens with respect to the d line. | ||
| 地址 | Tokyo JP | ||