发明名称 Zoom lens and image pickup apparatus having the same
摘要 A zoom lens includes an aperture stop and a plurality of lens units which are moved during zooming. The plurality of lens units includes, on an object side of the aperture stop, a lens unit Lp having a positive refractive power and a lens unit Ln having a negative refractive power which is disposed to be adjacent to an image side of the positive lens unit Lp. At least one of the positive lens unit Lp and the negative lens unit Ln includes two or less lenses which are moved during focusing, and a focal length Fp of the positive lens unit Lp and a focal length Fn of the negative lens unit Ln are appropriately set based on predetermined mathematical conditions.
申请公布号 US8760771(B2) 申请公布日期 2014.06.24
申请号 US201213440682 申请日期 2012.04.05
申请人 Canon Kabushiki Kaisha 发明人 Sugita Shigenobu
分类号 G02B15/14 主分类号 G02B15/14
代理机构 Canon USA Inc. IP Division 代理人 Canon USA Inc. IP Division
主权项 1. A zoom lens comprising: an aperture stop; and a plurality of lens units which are moved during zooming, wherein the plurality of lens units includes, on an object side of the aperture stop, a positive lens unit Lp having a positive refractive power and a negative lens unit Ln having a negative refractive power which is disposed to be adjacent to an image side of the positive lens unit Lp, wherein at least one of the positive lens unit Lp and the negative lens unit Ln includes two or less lenses which are moved during focusing, and wherein a composite focal length of lens units disposed on the image side of the negative lens unit Ln at a wide-angle end is positive, and a composite focal length of lens units disposed on the object side of the positive lens unit Lp at the wide-angle end is negative, wherein, when focal lengths of the positive and negative lens units Lp and Ln are respectively denoted by Fp and Fn, and a lateral magnification of the negative lens unit Ln at a wide-angle end is denoted by βnw, the following conditions are satisfied: 0.5<|Fp/Fn|<2.0,|βnw|<1.0.
地址 Tokyo JP