VARIABLE POWER OPTICAL SYSTEM, OPTICAL DEVICE, IMAGING DEVICE, AND METHOD FOR PRODUCING VARIABLE POWER OPTICAL SYSTEM

Title:

VARIABLE POWER OPTICAL SYSTEM, OPTICAL DEVICE, IMAGING DEVICE, AND METHOD FOR PRODUCING VARIABLE POWER OPTICAL SYSTEM

Document Type and Number:

WIPO Patent Application WO/2017/047757

Kind Code:

A1

Abstract:

The invention has a positive first group G1 that is disposed furthest to an object side, a negative intermediate group G2 that is disposed further to an image side than the first group G1, a positive focusing group G3 that is disposed further to the image side than the intermediate group G2 and moves during focusing, and a positive image-side group G4 that is disposed further to the image side than the focusing group G3, wherein the space between the first group G1 and the intermediate group G2, the space between the intermediate group G2 and the focusing group G3, and the space between the focusing group G3 and the image-side group G4 change when magnification is varied, and the image-side group G4 comprises, in order from the object side, a positive A group G4A, a negative B group G4B that satisfies a prescribed conditional expression for the A group G4A, and a C group G4C. This makes it possible to provide a variable power optical system that is provided with good optical performance and achieves a reduction in the weight of a focusing group with a view to increasing the speed of focusing.

Inventors:

MACHIDA KOSUKE (JP)

Application Number:

PCT/JP2016/077469

Publication Date:

March 23, 2017

Filing Date:

September 16, 2016

Export Citation:

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Assignee:

NIKON CORP (JP)

International Classes:

G02B15/20

Foreign References:

JP2012212087A	2012-11-01
JP2011090186A	2011-05-06
JP2014126766A	2014-07-07
JP2009086535A	2009-04-23
JP2009086537A	2009-04-23
JPH11295597A	1999-10-29
JP2012118097A	2012-06-21
JP2006201524A	2006-08-03

Other References: