发明名称 |
VARIABLE POWER OPTICAL SYSTEM, OPTICAL DEVICE, AND METHOD OF MANUFACTURING VARIABLE POWER OPTICAL SYSTEM |
摘要 |
A variable magnification optical system comprises, in order from an object side: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; a fourth lens group having positive refractive power; and a fifth lens group; upon varying magnification from a wide-angle end state to a telephoto end state, a distance between the first lens group and the second lens group, a distance between the second lens group and the third lens group, a distance between the third lens group and the fourth lens group and a distance between the fourth lens group and the fifth lens group being varied, the fifth lens group being moved with respect to the image plane; upon focusing the third lens group being moved along the optical axis; and the given conditional expressions being satisfied; thereby providing a small-size variable magnification optical system having a high variable magnification ratio and an excellent optical performance. |
申请公布号 |
US2017075093(A1) |
申请公布日期 |
2017.03.16 |
申请号 |
US201615331816 |
申请日期 |
2016.10.22 |
申请人 |
Nikon Corporation |
发明人 |
SASHIMA Tomoyuki;OBAMA Akihiko |
分类号 |
G02B15/173;G02B15/20;G02B5/00 |
主分类号 |
G02B15/173 |
代理机构 |
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代理人 |
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主权项 |
1. A variable magnification optical system comprising, in order from an object side: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; a fourth lens group having positive refractive power; and a fifth lens;
upon varying magnification from a wide-angle end state to a telephoto end state, a distance between the first lens group and the second lens group, a distance between the second lens group and the third lens group, a distance between the third lens group and the fourth lens group and a distance between the fourth lens group and the fifth lens group being varied, and the fifth lens group being moved with respect to the image plane; upon focusing, the third lens group being moved along the optical axis; and the following conditional expression being satisfied:
0.030<(−f2)/ft<0.120 where ft denotes a whole system focal length of the variable magnification optical system in the tele photo end state, and f2 denotes a focal length of the second lens group. |
地址 |
Tokyo JP |