Title:
ZOOM LENS SYSTEM, INTERCHANGEABLE LENS DEVICE, AND CAMERA SYSTEM
Document Type and Number:
WIPO Patent Application WO/2014/097355
Kind Code:
A1
Abstract:
This zoom lens system is provided with: a first lens group that has negative power; a second lens group that has positive power; a third lens group that has negative power; and a fourth lens group that has positive power. During zooming, the first lens group, second lens group, and third lens group move along the optical axis. During focusing, the third lens group moves along the optical axis. The zoom lens system satisfies the conditions: 2.5 ≤ | (1 - (β3T)2) × (β4T)2 | ≤ 7.0 and 0.5 ≤ BfW/fW ≤ 4.0 (β3T being the lateral magnification of the third lens group at an infinite object distance at the telephoto end; β4T the lateral magnification of the fourth lens group at an infinite object distance of the telephoto end; BfW the back focus of the entire system at the wide angle end; and fW the focal length of the entire system at the wide angle end).
Inventors:
IZUHARA ISAMU
ISHIDA AKIHIRO
ISHIDA AKIHIRO
Application Number:
PCT/JP2012/008137
Publication Date:
June 26, 2014
Filing Date:
December 19, 2012
Export Citation:
Assignee:
PANASONIC CORP (JP)
International Classes:
G02B15/20
Foreign References:
| JP2012133228A | 2012-07-12 | |||
| JP2007156367A | 2007-06-21 | |||
| JPH07287168A | 1995-10-31 | |||
| JP2000338397A | 2000-12-08 |
Attorney, Agent or Firm:
OGASAWARA PATENT OFFICE (JP)
Patent business corporation Ogasawara patent firm (JP)
Patent business corporation Ogasawara patent firm (JP)
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