Title:
VARIABLE MAGNIFICATION OPTICAL SYSTEM, OPTICAL DEVICE, AND PRODUCTION METHOD FOR VARIABLE MAGNIFICATION OPTICAL SYSTEM
Document Type and Number:
WIPO Patent Application WO/2019/049372
Kind Code:
A1
Abstract:
The present invention has, in order from the 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; and a rear lens group having positive refractive power. When the magnification state is changed from wide-angle to telephoto, the interval between the first lens group and the second lens group changes, the interval between the second lens group and the third lens group changes, and the interval between the third lens group and the rear lens group changes. The rear lens group has a focal lens group that moves when focusing from an infinite object to a close object and is capable of good correction of various aberrations by satisfying a prescribed conditional expression.
Inventors:
UMEDA TAKESHI (JP)
Application Number:
PCT/JP2017/032695
Publication Date:
March 14, 2019
Filing Date:
September 11, 2017
Export Citation:
Assignee:
NIKON CORP (JP)
International Classes:
G02B15/20; G02B13/18
Foreign References:
| JP2011099925A | 2011-05-19 | |||
| JP2011107188A | 2011-06-02 | |||
| JP2011128445A | 2011-06-30 | |||
| JP2011237832A | 2011-11-24 | |||
| JP2012042512A | 2012-03-01 | |||
| JP2012078788A | 2012-04-19 | |||
| JP2011022191A | 2011-02-03 | |||
| JP2011070220A | 2011-04-07 |
Attorney, Agent or Firm:
INOUE & CO. et al. (JP)
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