发明名称 ZOOM LENS AND IMAGING APPARATUS
摘要 A zoom lens includes, in order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power and a third lens group having a positive refractive power, wherein, during magnification change from the wide-angle end to the telephoto end, at least the first lens group and the second lens group are moved along the optical axis such that the interval between the first lens group and the second lens group is decreased and the interval between the second lens group and the third lens group is increased. The second lens group includes, in order from the object side, a positive lens, a cemented lens formed by a positive lens and a negative lens, a positive lens and a negative lens. The zoom lens satisfies given conditional expressions.
申请公布号 US2014293437(A1) 申请公布日期 2014.10.02
申请号 US201414299165 申请日期 2014.06.09
申请人 Fujifilm Corporation 发明人 NODA Taiga;CHO Michio
分类号 G02B13/04 主分类号 G02B13/04
代理机构 代理人
主权项 1. A zoom lens substantially consisting of three lens groups including, in order from an object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power and a third lens group having a positive refractive power, wherein, during magnification change from a wide-angle end to a telephoto end, at least the first lens group and the second lens group are moved along an optical axis such that an interval between the first lens group and the second lens group is decreased and an interval between the second lens group and the third lens group is increased, the second lens group consists of, in order from the object side, a second-group first lens having a positive refractive power, a cemented lens consisting of a second-group second lens having a positive refractive power and a second-group third lens having a negative refractive power, a second-group fourth lens having a positive refractive power, and a second-group fifth lens having a negative refractive power, and the conditional expressions (1) and (2) below are satisfied: −0.9<fw/f25<0  (1), and−0.40<(R15+R16)/(R15−R16)<2.40  (2),where fw is a focal length of the entire lens system at the wide-angle end, f25 is a focal length of the second-group fifth lens, R15 is a paraxial radius of curvature of an object-side surface of the second-group fifth lens, and R16 is a paraxial radius of curvature of an image-side surface of the second-group fifth lens.
地址 Tokyo JP