Zoom lens system and image pickup apparatus having the system
AssigneeCanon Kabushiki Kaisha
InventorDaisuke Ito
Life of this patent
Estimating the term…
Abstract
At least one exemplary embodiment is directed to a zoom lens system including, in order from an object side to an image side: a first lens unit having a negative optical power; a second lens unit having a positive optical power; and a third lens unit having a positive optical power. In this particular exemplary embodiment, the zoom lens system changes an interval between the first and second lens units, and an interval between the second and third lens units during zooming.
Claims42
A zoom lens system comprising, in order from an object side to an image side:
- a first lens unit having a negative optical power, wherein the first lens unit includes only, in order from the object side to the image side, a first negative lens element and a second positive lens element as the lens elements;
- a second lens unit having a positive optical power, wherein the second lens unit includes only, in order from the object side to the image side, a third positive lens element, a fourth positive lens element, a fifth negative lens element and a sixth positive lens element as the lens elements;
- and
- a third lens unit having a positive optical power,
- wherein an interval between the first and second lens units, and an interval between the second and third lens units change during zooming, and
- the third lens unit moves to the image side during the zooming from a wide-angle end to a telephoto end.
A zoom lens system comprising, in order from an object side to an image side:
- a first lens unit having a negative optical power:
- a second lens unit having a positive optical power;
- and
- a third lens unit having a positive optical power,
- wherein an interval between the first and second lens units, and an interval between the second and third lens units change during zooming, and
- assuming that a movement amount of the second lens unit during the zooming from a wide-angle end to a telephoto end is Δ2x, the interval between the second and third lens units in the wide-angle end is D23W, focal lengths of the first and second lens units are f1 and f2, respectively, and the focal length of the whole system in the wide-angle end is fW, the following conditions are satisfied:
- 1.7<Δ2×/√{square root over (|ƒ1*ƒ2|)}<2.3;
- and
- 0.5<D23W/fW<1.2.
A zoom lens system comprising, in order from an object side to an image side:
- a first lens unit having a negative optical power, wherein the first lens unit includes only two lens elements as the lens elements:
- a second lens unit having a positive optical power;
- and
- a third lens unit having a positive optical power,
- wherein an interval between the first and second lens units, and an interval between the second and third lens units change during zooming, and
- assuming that a movement amount of the second lens unit during the zooming from a wide-angle end to a telephoto end is Δ2×, and focal lengths of the first and second lens units are f1 and f2, respectively, the following condition is satisfied:
- 1.7<Δ2×/√{square root over (|ƒ1*ƒ2|)}<2.3.
Dependencies are inferred from the claim text.