Title:
VARIABLE POWER OPTICAL SYSTEM, OPTICAL APPARATUS, AND PRODUCTION METHOD FOR VARIABLE POWER OPTICAL SYSTEM
Document Type and Number:
WIPO Patent Application WO/2020/012638
Kind Code:
A1
Abstract:
Provided is a variable power optical system that is compact and has favorable optical performance. The variable power optical system has, in order from an object side, a first lens group that has negative refractive power, a second lens group that has positive refractive power, a third lens group that has negative refractive power, and a fourth lens group that has positive refractive power. During changes in magnification, the distance between the first lens group and the second lens group changes, the distance between the second lens group and the third lens group changes, and the distance between the third lens group and the fourth lens group changes. The first lens group comprises, in order from the object side, a negative lens and a positive lens. The second lens group comprises, in order from the object side, a 2a lens group that has positive refractive power, a 2b lens group that has positive refractive power, and a 2c lens group that has negative refractive power.
Inventors:
KOMATSUBARA YOKO (JP)
UMEDA TAKESHI (JP)
UMEDA TAKESHI (JP)
Application Number:
PCT/JP2018/026486
Publication Date:
January 16, 2020
Filing Date:
July 13, 2018
Export Citation:
Assignee:
NIKON CORP (JP)
International Classes:
G02B15/20; G02B13/18
Domestic Patent References:
| WO2012086153A1 | 2012-06-28 |
Foreign References:
| JP2012133229A | 2012-07-12 | |||
| JP2010181787A | 2010-08-19 | |||
| JP2011059496A | 2011-03-24 | |||
| JP2012022106A | 2012-02-02 | |||
| JP2006119193A | 2006-05-11 | |||
| JPH10333034A | 1998-12-18 | |||
| JPH0829685A | 1996-02-02 | |||
| JP2013218256A | 2013-10-24 | |||
| JPS6332513A | 1988-02-12 |
Attorney, Agent or Firm:
INOUE & CO. et al. (JP)
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