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US 6,285,502 B1Granted
Zoom lens system having an image blur compensation function
AssigneeMinolta Co., Ltd.
InventorsKenji Konno, Kohtaro Hayashi
Life of this patent
Estimating the term…
Abstract
A zoom lens system has the first to fifth lens units from the object side. Refractive powers of the first to fifth lens units are positive, negative, negative, positive, negative, respectively. During zooming, the distances between the lens units are varied. Image blur compensation is made by parallel decentering the second lens unit. When f2 is the focal length of the second lens unit, f5 is the focal length of the fifth lens unit, and fw is the focal length of the entire lens system, then the following conditions are satisfied. 0.2<|f2/fw|<4.0 0.2<|f5/fw|<0.4
Claims14
A zoom lens system comprising from an object side:
- a first lens unit having a positive refractive power, said first lens unit being moved toward the object side during zooming from a wide-angle limit to a telephoto limit;
- a second lens unit having a negative refractive power, said second lens unit being moved vertically to an optical axis to compensate for an image blur;
- a third lens unit;
- a fourth lens unit having a positive refractive power;
- and
- a fifth lens unit having a negative refractive power, said fifth lens unit being moved toward the object side during zooming from the wide-angle limit to the telephoto limit,
- wherein said zoom lens system fulfills the following conditions:
- 0.2<|f5/fW|<0.4
- 0.2<|f2/fW|<4.0
- where f5 is a focal length of the fifth lens unit, fW is a focal length of the entire zoom lens system at the wide-angle limit, and f2 is a focal length of the second lens unit.
7 more elements
A zoom lens system comprising from an object side:
- a first lens unit having a positive refractive power, said first lens unit being moved toward the object side during zooming from a wide-angle limit to a telephoto limit;
- a second lens unit having a negative refractive power, said second lens unit being moved vertically to an optical axis to compensate for an image blur;
- and
- a most image side lens unit having a negative refractive power, said most image side lens unit being moved toward the object side during zooming from the wide-angle limit to the telephoto limit,
- wherein said zoom lens system has at least five lens units,
- wherein zooming is performed by varying each of distance between said lens units, and
- wherein said zoom lens system fulfills the following conditions:
- 0.2<|fL/fW|<0.4
- 0.2<|f2/fW|<4.0
- where fL is a focal length of the most image side lens unit, fW is a focal length of the entire zoom lens system at the wide-angle limit, and f2 is a focal length of the second lens unit.
7 more elements
A zoom lens system comprising from an object side:
- a first lens unit having a positive refractive power, said first lens unit being moved toward the object side during zooming from a wide-angle limit to a telephoto limit;
- a second lens unit having a negative refractive power;
- a third lens unit having a positive refractive power;
- a fourth lens unit;
- and
- a fifth lens unit,
- wherein any of the second lens unit and lens units disposed on an image side of the second lens unit comprises from the object side a front lens unit and a rear lens unit, either said front or said rear lens unit being moved vertically to an optical axis to compensate for an image blur, wherein the following condition is fulfilled:
- 2.1<f1/fW<4.3
- where f1 is a focal length of the first lens unit, and fW is a focal length of the entire zoom lens system at the wide-angle limit.
6 more elements
A zoom lens system comprising from an object side:
- a first lens unit having a positive refractive power, said first lens unit being moved toward the object side during zooming from a wide-angle limit to a telephoto limit;
- a second lens unit having a negative refractive power;
- a third lens unit having a positive refractive power;
- a fourth lens unit having a positive refractive power;
- and
- a fifth lens unit having a negative refractive power,
- wherein any of the second lens unit and lens units disposed on an image side of the second lens unit comprises from the object side a front lens unit and a rear lens unit, either said front lens unit or said rear lens unit being moved vertically to an optical axis to compensate for an image blur, wherein the following condition is fulfilled:
- 2.1<f1/fW<4.3
- where f1 is a focal length of the first lens unit, and fW is a focal length of the entire zoom lens system at the wide-angle limit.
6 more elements
Dependencies are inferred from the claim text.