Title:
VARIABLE MAGNIFICATION OPTICAL SYSTEM, OPTICAL DEVICE, AND PRODUCTION METHOD FOR VARIABLE MAGNIFICATION OPTICAL SYSTEM
Document Type and Number:
WIPO Patent Application WO/2020/105103
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 a final lens group positioned nearest the image side. The variable magnification optical system (ZL) satisfies the following conditional expression. -10.00 < f3/(–fE) < 3.50, where f3 is the focal length of the third lens group (G3) and fE is the focal length of the final lens group.
Inventors:
UEHARA TAKERU (JP)
Application Number:
PCT/JP2018/042762
Publication Date:
May 28, 2020
Filing Date:
November 20, 2018
Export Citation:
Assignee:
NIKON CORP (JP)
International Classes:
G02B15/20
Foreign References:
| JP2018054989A | 2018-04-05 | |||
| JP2018097240A | 2018-06-21 |
Attorney, Agent or Firm:
OHNISHI, Shogo et al. (JP)
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