Title:
VARIABLE MAGNIFICATION OPTICAL SYSTEM, OPTICAL DEVICE, AND PRODUCTION METHOD FOR VARIABLE MAGNIFICATION OPTICAL SYSTEM
Document Type and Number:
WIPO Patent Application WO/2020/105104
Kind Code:
A1
Abstract:
A variable magnification optical system (ZL) includes, arranged in order from the object side: a first lens group (G1) having positive refractive power; a second lens group (G2) having negative refractive power; a third lens group (G3) having positive refractive power; and a subsequent lens group (GR). When zooming, the interval between adjacent groups changes, and the first lens group (G1) is fixed with respect to the image plane, and when zooming from the wide-angle end state to the telephoto end state, the third lens group (G3) moves to the image side. The subsequent lens group (GR) has, arranged in order from the object side, a first focusing lens group having negative refractive power that moves when focusing, and a second focusing lens group having positive refractive power that moves when focusing. The variable magnification optical system (ZL) satisfies the following conditional expression. 0.80 < (–fF1)/fF2 < 5.00, where fF1 is the focal length of the first focusing lens group, and fF2 is the focal length of the second focusing lens group.
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Inventors:
UEHARA TAKERU (JP)
Application Number:
PCT/JP2018/042763
Publication Date:
May 28, 2020
Filing Date:
November 20, 2018
Export Citation:
Assignee:
NIKON CORP (JP)
International Classes:
G02B15/20; G02B13/18
Foreign References:
| JP2018092185A | 2018-06-14 | |||
| JP2018054989A | 2018-04-05 | |||
| JP2016173438A | 2016-09-29 | |||
| JP2016139125A | 2016-08-04 |
Attorney, Agent or Firm:
OHNISHI, Shogo et al. (JP)
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