Zoom lens and image pickup apparatus including the same
AssigneeCanon Kabushiki Kaisha
InventorHideki Sakai
Life of this patent
Estimating the term…
Abstract
A zoom lens includes, in order from an object side to an image side: a positive first lens unit; a positive second lens unit; and an aperture stop disposed between the first and second lens units and moving along a locus different from loci of the first and the second lens units during zooming, the first and second lens units being configured to change an interval therebetween during zooming, the second lens unit including at least one positive lens and at least one negative lens. A distance from a lens surface closest to the object side in the entire system to the aperture stop at a wide angle end, and a distance from the lens surface closest to the object side in the entire system to a lens surface closest to the object side in the second lens unit at the wide angle end are each appropriately set.
Claims10
A zoom lens, comprising, in order from an object side to an image side:
- a first lens unit having a negative refractive power;
- a second lens unit having a positive refractive power;
- and
- an aperture stop disposed between the first lens unit and the second lens unit, the aperture stop moving along a locus different from loci of the first lens unit and the second lens unit during zooming,
- an interval between any lens units adjacent to each other being changed during zooming,
- the second lens unit including at least one positive lens and at least one negative lens, and
- wherein the following conditional expression is satisfied:
- 0.40<Dsw/D2w<0.60,
- where Dsw represents a distance on an optical axis from a lens surface closest to the object side in the zoom lens to the aperture stop at a wide angle end, and D2w represents a distance on the optical axis from the lens surface closest to the object side in the zoom lens to a lens surface closest to the object side in the second lens unit at the wide angle end.
An image pickup apparatus comprising:
- a zoom lens;
- and
- an image sensor configured to receive an image formed by the zoom lens,
- the zoom lens comprising, in order from an object side to an image side:
- a first lens unit having a negative refractive power;
- a second lens unit having a positive refractive power;
- and
- an aperture stop disposed between the first lens unit and the second lens unit, the aperture stop moving along a locus different from loci of the first lens unit and the second lens unit during zooming,
- an interval between any lens units adjacent to each other being changed during zooming,
- the second lens unit including at least one positive lens and at least one negative lens, and
- wherein the following conditional expression is satisfied:
- 0.40<Dsw/D2w<0.60,
- where Dsw represents a distance on an optical axis from a lens surface closest to the object side in the zoom lens to the aperture stop at a wide angle end, and D2w represents a distance on the optical axis from the lens surface closest to the object side in the zoom lens to a lens surface closest to the object side in the second lens unit at the wide angle end.
Dependencies are inferred from the claim text.