Title:
ZOOM LENS AND IMAGING DEVICE
Document Type and Number:
WIPO Patent Application WO/2011/145288
Kind Code:
A1
Abstract:
Disclosed is a zoom lens that enables lower costs, suppression of temperature fluctuation effects, and satisfactory correction of aberrations. The zoom lens has a first lens group to a fourth lens group, in order from the object side to the image side, and changes magnitude by changing the spacing between same. The first and third lens groups have a negative refractive power and the second and fourth lens groups have a positive refractive power. The spacing between the first lens group and the second lens group reduces as the magnification is changed from the wide-angle end towards the telephoto end. The first lens group includes a reflective optical element that changes the advancing direction of a light beam. The second lens group includes at least two lenses, of which the lens on the side closest to the image is a single lens made from plastic and has a positive refractive power. The third lens group is formed by one negative lens made of plastic. The following condition is satisfied when f2L represents the focal length of the single lens on the side closest to the image in the second lens group, and f3 represents the focal length of the third lens group: 0.60 <｜f2L / f3｜< 1.60.
Inventors:
OZAKI YUICHI (JP)
Application Number:
PCT/JP2011/002591
Publication Date:
November 24, 2011
Filing Date:
May 10, 2011
Export Citation:
Assignee:
KONICA MINOLTA OPTO INC (JP)
OZAKI YUICHI (JP)
OZAKI YUICHI (JP)
International Classes:
G02B15/167; G02B13/18
Foreign References:
| JP2007232974A | 2007-09-13 | |||
| JP2011059497A | 2011-03-24 | |||
| JP2010152144A | 2010-07-08 | |||
| JP2010152147A | 2010-07-08 |
Attorney, Agent or Firm:
MISAWA PATENT OFFICE, p. c. (JP)
Patent business corporation Misawa patent firm (JP)
Patent business corporation Misawa patent firm (JP)
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Claims: