Title:
VARIABLE MAGNIFICATION OPTICAL SYSTEM, OPTICAL DEVICE, AND METHOD FOR PRODUCING VARIABLE MAGNIFICATION OPTICAL SYSTEM
Document Type and Number:
WIPO Patent Application WO/2016/104786
Kind Code:
A1
Abstract:
This variable magnification optical system has a first lens group (G1) that is disposed furthest to an object side and has a positive refractive power, a negative lens group (G2) that is disposed further to an image side than the first lens group and has a negative refractive power, a positive lens group (G4) that is disposed further to the image side than the negative lens group and has a positive refractive power, and a focusing group (G3) that is disposed between the negative lens group and the positive lens group, wherein: when magnification is varied, the space between the first lens group and the negative lens group changes, and the space between the negative lens group and the positive lens group changes; during focusing, the space between the focusing group and a lens that is disposed in a position facing the object side of the focusing group changes, and the space between the focusing group and a lens that is disposed in a position facing the image side of the focusing group changes; and the focusing group comprises one single lens (L31) having a positive refractive power and satisfies a prescribed conditional expression.
Inventors:
YAMAMOTO HIROSHI (JP)
MATSUO TAKU (JP)
OBAMA AKIHIKO (JP)
UCHIDA KENSUKE (JP)
MATSUO TAKU (JP)
OBAMA AKIHIKO (JP)
UCHIDA KENSUKE (JP)
Application Number:
PCT/JP2015/086410
Publication Date:
June 30, 2016
Filing Date:
December 25, 2015
Export Citation:
Assignee:
NIKON CORP (JP)
International Classes:
G02B15/20
Domestic Patent References:
| WO2013146758A1 | 2013-10-03 |
Foreign References:
| JPH11344672A | 1999-12-14 | |||
| JP2002341243A | 2002-11-27 | |||
| JP2001033698A | 2001-02-09 | |||
| JPH07113955A | 1995-05-02 |
Attorney, Agent or Firm:
SHIGA Masatake et al. (JP)
Masatake Shiga (JP)
Masatake Shiga (JP)
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