Title:
VARIABLE MAGNIFICATION OPTICAL SYSTEM, OPTICAL DEVICE, IMAGING DEVICE, AND MANUFACTURING METHOD OF VARIABLE MAGNIFICATION OPTICAL SYSTEM
Document Type and Number:
WIPO Patent Application WO/2018/092297
Kind Code:
A1
Abstract:
This variable magnification optical system comprises, in order from the object side, a front lens group (GFS) having positive refractive power, an M1 lens group (GM1) having negative refractive power, an M2 lens group (GM2) having positive refractive power, and an RN lens group (GRN) having negative refractive power. When changing magnification, the interval between the front lens group and the M1 lens group, the interval between the M1 lens group and the M2 lens group, and the interval between the M2 lens group and the RN lens group each changes, and, when focusing from an object at infinity to a near object, the RN lens group moves. The M2 lens group has an A lens group that satisfies the following condition:
1.10 < fvr / fTM2 < 2.00
wherein
fvr: the focal length of the A lens group
fTM2: the focal length of the M2 lens group in the telephoto end state
Inventors:
MACHIDA KOSUKE (JP)
Application Number:
PCT/JP2016/084397
Publication Date:
May 24, 2018
Filing Date:
November 21, 2016
Export Citation:
Assignee:
NIKON CORP (JP)
International Classes:
G02B15/20
Foreign References:
| JP2012047814A | 2012-03-08 | |||
| JP2009282398A | 2009-12-03 | |||
| JPH10268195A | 1998-10-09 | |||
| JP2009180844A | 2009-08-13 | |||
| JP2012212106A | 2012-11-01 | |||
| JP2009175202A | 2009-08-06 |
Attorney, Agent or Firm:
OHNISHI, Shogo et al. (JP)
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