Zoom lens having focusing subunit in second lens unit and optical apparatus equipped with the same
AssigneeCanon Kabushiki Kaisha
InventorMakoto Misaka
Life of this patent
Estimating the term…
Abstract
A small-sized zoom lens in which the displacement of the focusing lens unit does not increase to an excessive degree during focusing, the zoom lens including a first lens unit of positive refractive power; a second lens unit of negative refractive power; and a subsequent lens unit of positive refractive power in that order from the object side, wherein focusing is effected by a subunit 2b of negative refractive power constituting a part of the second lens unit and wherein, assuming that the magnification of the subunit 2b at the wide-angle end is .beta.2bw, the following condition is satisfied: 0<.beta.2bw<1.
Claims24
A zoom lens comprising, in order from a long conjugate side:
- a first lens unit of positive refractive power;
- a second lens unit of negative refractive power, said second lens unit comprising a first lens subunit of negative refractive power and a second lens subunit of negative refractive power which is closer to a short conjugate side than said first lens subunit, focusing being performed by moving said second lens subunit in the optical axis direction while keeping said first lens subunit stationary;
- and
- a subsequent lens unit comprising at least one lens unit, said subsequent lens unit being of positive refractive power as a whole,
- wherein, when a variation in power is effected from a wide-angle end to a telephoto end, a distance between said first lens unit and said second lens unit increases and a distance between said second lens unit and said subsequent lens unit decreases, and
- wherein, assuming that the magnification of said second lens subunit at the wide-angle end is .beta.2bw, the following condition is satisfied:
- 0<.beta.2bw<1.
A zoom lens comprising, in order from the object side to the image side:
- a first lens unit of positive refractive power;
- a second lens unit of negative refractive power, said second lens unit comprising, in order from the object side to the image side, a first lens subunit of negative refractive power and a second lens subunit of negative refractive power, focusing being performed by moving said second lens subunit in the optical axis direction while keeping said first lens subunit stationary;
- and
- one or more lens units having, as a whole, positive refractive power,
- wherein, when variation in power is effected from a wide-angle end to a telephoto end, a distance between said first lens unit and said second lens unit increases and a distance between said second lens unit and said one or more lens units decreases, and
- wherein, assuming that the magnification of said second lens subunit at the wide-angle end is .beta.2bw, the following condition is satisfied:
- 0<.beta.2bw<1.
Dependencies are inferred from the claim text.