Zoom lens and camera having the same
AssigneeCanon Kabushiki Kaisha
InventorKen Wada
Life of this patent
Estimating the term…
Abstract
A zoom lens includes, in order from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a reflection unit including a reflection surface for bending an optical path, a third lens unit having a negative refractive power, a fourth lens unit having a positive refractive power, and a fifth lens unit having one of a positive refractive power and a negative refractive power. In the zoom lens, at least the second lens unit and the fourth lens unit move during zooming while the reflection unit remains stationary. In addition, a focal length of the first lens unit and respective focal lengths of the zoom lens at a wide-angle end and at a telephoto end are appropriately set.
Claims7
A zoom lens comprising, in order from an object side to an image side:
- a first lens unit having a positive refractive power;
- a second lens unit having a negative refractive power;
- a reflection unit including a reflection surface for bending an optical path,
- a third lens unit having a negative refractive power;
- a fourth lens unit having a positive refractive power;
- and
- a fifth lens unit having one of a positive refractive power and a negative refractive power,
- wherein during zooming from a wide-angle end to a telephoto end, at least the second lens unit and the fourth lens unit move while the reflection unit remains stationary, and
- wherein a focal length of the first lens unit (f1) and focal lengths of the zoom lens at the wide-angle end and at the telephoto end (fw, ft) satisfy the following condition:
- 0.7<f1/√{square root over (fw·ft)}≦1.7.
Dependencies are inferred from the claim text.