Title:
ZOOMING OPTICAL SYSTEM, IMAGING DEVICE, AND DIGITAL APPARATUS
Document Type and Number:
WIPO Patent Application WO/2008/075566
Kind Code:
A1
Abstract:
A zooming optical system in which the weight of lenses of a movable lens group is decreased
to reduce a load on a lens drive device and that is compact. The zooming optical
system has, in order from the object side, first to third lens groups having negative,
positive, and positive optical power. The second lens group moves in zooming
operation. The first lens group is constructed from a negative lens and a positive
lens that are made of plastic.The zooming optical system satisfies the conditional
expressions of 0.5 < |f1/f2| < 1.4, 0.5 < f2/fw < 2.0, -3.2 <β2t
< -1.4, where f1 is the focal length of the first lens group, f2 is the focal length
of the second lens group, fw is the combined focal length of the entire optical
system at the wide angle end, and β2t is the magnification of image formation
of the second lens group (12).
Inventors:
FUKUTA YASUNARI (JP)
MATSUSAKA KEIJI (JP)
OHZAWA SOH (JP)
MATSUSAKA KEIJI (JP)
OHZAWA SOH (JP)
Application Number:
PCT/JP2007/073576
Publication Date:
June 26, 2008
Filing Date:
December 06, 2007
Export Citation:
Assignee:
KONICA MINOLTA OPTO INC (JP)
FUKUTA YASUNARI (JP)
MATSUSAKA KEIJI (JP)
OHZAWA SOH (JP)
FUKUTA YASUNARI (JP)
MATSUSAKA KEIJI (JP)
OHZAWA SOH (JP)
International Classes:
G02B15/163; G02B13/18; G02B15/167
Foreign References:
| JP2003228002A | 2003-08-15 | |||
| JP2004061675A | 2004-02-26 | |||
| JP2004205813A | 2004-07-22 | |||
| JP2005283709A | 2005-10-13 | |||
| JP2004333767A | 2004-11-25 | |||
| JP2004093917A | 2004-03-25 | |||
| JP2006145823A | 2006-06-08 |
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