Zoom lens and image pickup apparatus having the same
AssigneeCanon Kabushiki Kaisha
InventorYotaro Sanjo
Life of this patent
Estimating the term…
Abstract
The zoom lens includes, in order from an object side to an image side: a first lens unit having a positive refractive power that does not move for zooming; a second lens unit having a negative refractive power that moves during zooming; at least one lens unit that moves during zooming; and a rear lens group including an aperture stop, wherein the rear lens group has a zooming rear lens unit that moves during zooming, and a refractive power of the rear lens group at a wide-angle end, a refractive power of the zooming rear lens unit, and a lateral magnification of the lens unit in the image side from the zooming rear lens unit, which is set at the wide-angle end and focuses on infinity, are appropriately set.
Claims12
A zoom lens comprising, in order from an object side to an image side:
- a first lens unit having a positive refractive power that does not move for zooming;
- a second lens unit having a negative refractive power that moves during zooming;
- at least one lens unit that moves during zooming;
- and a rear lens group including an aperture stop, wherein
- the rear lens group includes a zooming rear lens unit that moves during zooming, and
- the following conditional expressions are satisfied,
- |φrz/φr—W|<0.90, and
- φβrzb—W|<2.00,
- where φr_W represents a refractive power of the rear lens group at a wide-angle end, φrz represents a refractive power of the zooming rear lens unit, and βrzb_W represents a lateral magnification of a lens unit in the image side from the zooming rear lens unit, which is set at the wide-angle end and focuses on infinity.
An image pickup apparatus comprising:
- a zoom lens comprising, in order from an object side to an image side:
- a first lens unit having a positive refractive power that does not move for zooming;
- a second lens unit having a negative refractive power that moves during zooming;
- at least one lens unit that moves during zooming;
- and a rear lens group including an aperture stop, wherein
- the rear lens group includes a zooming rear lens unit that moves during zooming, and
- the following conditional expressions are satisfied,
- |φrz/φr—W|<0.90, and
- |βrzb—W|<2.00,
- where φr_W represents a refractive power of the rear lens group at a wide-angle end, φrz represents a refractive power of the zooming rear lens unit, and βrzb_W represents a lateral magnification of a lens unit in the image side from the zooming rear lens unit, which is set at the wide-angle end and focuses on infinity;
- and
- an image pickup element.
Dependencies are inferred from the claim text.