Zoom lens and image pickup apparatus including the same
AssigneeCanon Kabushiki Kaisha
InventorYotaro Sanjo
Life of this patent
Estimating the term…
Abstract
Provided is a zoom lens, including, 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 unit including an aperture stop, in which a focal length of the zoom lens at a wide angle end, a focal length of the first lens unit, a focal length of the second lens unit, and a half angle of field of the zoom lens at the wide angle end are appropriately set.
Claims9
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 unit including an aperture stop,
- the zoom lens satisfying the following expressions:
- −12.00<f1/f2<−4.00;
- and
- −1.00<f2/(2×fW×tan(ω—W))<−0.30,
- where fW represents a focal length of the zoom lens at a wide angle end, f1 represents a focal length of the first lens unit, f2 represents a focal length of the second lens unit, and ω_W represents a half angle of field of the zoom lens at the wide angle end.
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 unit including an aperture stop,
- the zoom lens satisfying the following expressions:
- −12.00<f1/f2<−4.00;
- and
- −1.00<f2/(2×fW×tan(ω—W))<−0.30,
- where fW represents a focal length of the zoom lens at a wide angle end, f1 represents a focal length of the first lens unit, f2 represents a focal length of the second lens unit, and ω_W represents a half angle of field of the zoom lens at the wide angle end;
- and
- an image pickup element.
Dependencies are inferred from the claim text.