Zoom lens system
AssigneeHoya Corporation
InventorKoichiro Hayakawa
Life of this patent
Estimating the term…
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AssigneeHoya Corporation
InventorKoichiro Hayakawa
Estimating the term…
A zoom lens system includes a negative first lens group, a positive second lens group, and a positive third lens group. The second lens group includes a positive lens element, and two negative lens elements. The following conditions (1) and (2) are satisfied: 2.0<|VD1t−VD1w|/(ft/fw)<3.4 (1), and 0.89<|m2w/m3w| (2), wherein VD1t and VD1w designate the distances, at the long and short focal length extremities, from the image-side surface of the lens element provided closest to the image side within the first lens group to the object-side surface of the positive lens element provided closest to the object side within the second lens group; ft and fw designate the entire focal length of the zoom lens system at the long and short focal length extremities; and m2w and m3w designate the lateral magnification of the second and third lens groups at the short focal length extremity when focused on an object at infinity.
A zoom lens system comprising a negative first lens group, a positive second lens group, and a positive third lens group, in that order from the object side,
Dependencies are inferred from the claim text.