Zoom lens including four lens groups
AssigneeFujinon Corporation
InventorKenichi Sato
Life of this patent
Estimating the term…
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AssigneeFujinon Corporation
InventorKenichi Sato
Estimating the term…
A zoom lens that is designed to enable a thinner image pickup device includes, in order from the object side, a first lens group having positive refractive power and a reflecting surface for folding the optical axis of the zoom lens approximately ninety degrees, a second lens group having negative refractive power, a third lens group having positive refractive power with a stop at its image side, and a fourth lens group having positive refractive power. The second lens group and the fourth lens group move along the optical axis during zooming, and the fourth lens group moves along the optical axis during focusing. The four lens groups have particular constructions and the zoom lens satisfies specified conditions related to the focal lengths of specified lens groups, the focal length of the zoom lens at the telephoto end, and the Abbe number of a specified lens element.
A zoom lens having an object side and an image side and comprising, arranged along an optical axis in order from the object side as follows:
Dependencies are inferred from the claim text.