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Patent Searching and Data


Title:
ZOOM LENS AND IMAGING DEVICE
Document Type and Number:
WIPO Patent Application WO/2006/092966
Kind Code:
A1
Abstract:
A zoom lens has arranged in it four lens groups that are, in sequence from the object side, a first lens group (G1) having a positive refractive power, a second lens group (G2) having a negative refractive power, a third lens group (G3) having a positive refractive power, and a fourth lens group (G4) having a positive refractive power. When the state of lens positions is varied from a wide end state to a tele end state, the second lens group moves to the image side and the fourth lens group moves so as to compensate a positional variation in the position of an image surface which variation is caused by the movement of the second lens group. At this time, the first lens group and the third lens group are fixed in the optical axis direction. Further, an aperture stop S is placed on the object side of the third lens group. Also, the third lens group is constructed from a negative section group having a negative refractive power and a positive section group having a positive refractive power, where the positive section group is placed on the image side of the negative section group with an air gap from the negative section group. The zoom lens satisfies (1) 0.4 < Da/TL < 0.5, where Da is the distance from the aperture stop to an image field and TL is the entire length of the lens (the distance in the optical axis direction, from that lens surface of the lens system which is the closest to the object to the position of an image surface.

Inventors:
OHTAKE MOTOYUKI
OKAJIMA KOJI
SUZAKI MITSUHIRO
Application Number:
PCT/JP2006/302816
Publication Date:
September 08, 2006
Filing Date:
February 17, 2006
Export Citation:
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Assignee:
SONY CORP (JP)
OHTAKE MOTOYUKI
OKAJIMA KOJI
SUZAKI MITSUHIRO
International Classes:
G02B15/16; G02B13/18
Foreign References:
JP2003098434A2003-04-03
JPH11237550A1999-08-31
JP2006047771A2006-02-16
JPH06337353A1994-12-06
JP2002365544A2002-12-18
JPH07128619A1995-05-19
Other References:
See also references of EP 1855138A4
Attorney, Agent or Firm:
Nakamura, Tomoyuki c/o Miyoshi International Patent Office ToranomonKotohira Tower 2-8 (Toranomon 1-chome Minato-ku, Tokyo 01, JP)
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