Optical system and optical apparatus having the same
AssigneeCanon Kabushiki Kaisha
InventorsAkihiro Nishio, Hideki Ogawa, Makoto Misaka
Life of this patent
Estimating the term…
Abstract
An optical system includes, in order from an object side, a first lens unit of positive refractive power, a second lens unit of negative refractive power, the second lens unit being movable along an optical axis to effect focusing, and a third lens unit of positive refractive power, the third lens unit including, in order from the object side, a first lens subunit of positive refractive power, a second lens subunit of negative refractive power and a third lens subunit of positive refractive power, wherein the second lens subunit is movable in directions perpendicular to the optical axis to displace an image formed by the optical system.
Claims24
An optical system comprising, in order from an object side to an image side:
- a first lens unit of positive refractive power;
- a second lens unit of negative refractive power;
- said second lens unit being movable along an optical axis to effect focusing;
- and
- a third lens unit of positive refractive power, said third lens unit comprising, in order from the object side to the image side, a first lens subunit of positive refractive power, a second lens subunit of negative refractive power and a third lens subunit of positive refractive power,
- wherein said second lens subunit is movable in directions perpendicular to the optical axis to displace an image formed by said optical system.
An optical system comprising, in order from an object side to an image side:
- a first lens unit of positive refractive power, said first lens unit consisting of, with boundaries formed by the widest and the second-widest spaces thereof, in order from the object side to the image side, a front lens subunit of positive refractive power, a middle lens subunit of negative refractive power and a rear lens subunit of positive refractive power;
- and
- a second lens unit of negative refractive power, said second lens unit being movable along an optical axis to effect focusing,
- wherein, letting a focal length of the entire optical system be denoted by f, a focal length of said front lens subunit be denoted by f1a, and a space between said front lens subunit and said middle lens subunit be denoted by D1ab, the following conditions are satisfied:
- 0.4<f1a/f<1.1
- 0.035<D1ab/f<0.15.
Dependencies are inferred from the claim text.