Title:
OPTICAL ZOOM SYSTEM, OPTICAL DEVICE, AND METHOD FOR MANUFACTURING ZOOM OPTICAL SYSTEM
Document Type and Number:
WIPO Patent Application WO/2013/146758
Kind Code:
A1
Abstract:
An optical zoom system includes, from the object side along an optical axis, a first lens group with a positive power, a second lens group with a negative power, a third lens group with a positive power, and a fourth lens group with a positive power. When zooming from a wide angle end state into a telephoto end state, 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 third lens group is constituted by a single positive lens. By moving the third lens group in the optical axis direction, focusing is performed from an object at infinity to a near object.
Inventors:
YOKOI NORIKAZU (JP)
Application Number:
PCT/JP2013/058729
Publication Date:
October 03, 2013
Filing Date:
March 26, 2013
Export Citation:
Assignee:
NIKON CORP (JP)
International Classes:
G02B15/20; G03B5/00
Foreign References:
| CN102073128A | 2011-05-25 | |||
| JPH11344672A | 1999-12-14 | |||
| JPH07318865A | 1995-12-08 | |||
| JPH0545584A | 1993-02-23 | |||
| JPH08122640A | 1996-05-17 | |||
| JPH08101362A | 1996-04-16 | |||
| JP2009251118A | 2009-10-29 | |||
| JPH0527172A | 1993-02-05 | |||
| JP2008216440A | 2008-09-18 | |||
| JP2012133104A | 2012-07-12 |
Attorney, Agent or Firm:
INOUE, Yoshio et al. (JP)
Yoshio Inoue (JP)
Yoshio Inoue (JP)
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