Title:
ZOOM LENS AND IMAGING DEVICE
Document Type and Number:
WIPO Patent Application WO/2011/062076
Kind Code:
A1
Abstract:
Provided is a zoom lens that, while being smaller than conventional models, has a low F-number and has aberrations well-corrected. In order from the object side, the provided zoom lens comprises a first lens group having negative refractive power, a second lens group having positive refractive power, a third lens group having negative refractive power, and a fourth lens group having positive refractive power. Magnification is changed by changing the spacing between the lens groups; the zoom lens goes from wide-angle to telescopic as the spacing between the first and second lens groups decreases. The first lens group contains a reflective optical element that bends the light path. In order from the object side, the second lens group comprises a positive 2p1 lens, a negative 2n lens, and a positive 2p2 lens. The third lens group comprises a single negative lens. Letting n2n be the index of refraction of the 2n lens, n2p2 be the index of refraction of the 2p2 lens, ν2p2 be the Abbe number of the 2p2 lens, and ν2n be the Abbe number of the 2n lens, 0.30 < n2n − n2p2 < 0.50 and 30 <ν2p2 − ν2n < 60.
Inventors:
OZAKI YUICHI (JP)
YAMASHITA ATSUSHI (JP)
YAMASHITA ATSUSHI (JP)
Application Number:
PCT/JP2010/069798
Publication Date:
May 26, 2011
Filing Date:
November 08, 2010
Export Citation:
Assignee:
KONICA MINOLTA OPTO INC (JP)
OZAKI YUICHI (JP)
YAMASHITA ATSUSHI (JP)
OZAKI YUICHI (JP)
YAMASHITA ATSUSHI (JP)
International Classes:
G02B15/167; G02B13/18
Domestic Patent References:
| WO2008075539A1 | 2008-06-26 |
Foreign References:
| JP2009216941A | 2009-09-24 | |||
| JP2007232974A | 2007-09-13 | |||
| JP2008233611A | 2008-10-02 | |||
| JP2008040485A | 2008-02-21 |
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