Optical system and imaging apparatus having the same
AssigneeCanon Kabushiki Kaisha
InventorsTomohiro Ino, Maki Yokoya
Life of this patent
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Abstract
An optical system consists of, in order from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a positive refractive power, a third lens unit having a negative refractive power. A distance between adjacent lens units changes during focusing. The second lens unit moves during the focusing. The following conditional expression is satisfied: −0.20<f3/f<−0.05 where f is a focal length of the optical system focused on an object at infinity and f3 is a focal length of the third lens unit.
Claims20
An optical system consisting of, in order from an object side to an image side:
- a first lens unit having a positive refractive power;
- a second lens unit having a positive refractive power;
- and
- a third lens unit having a negative refractive power,
- wherein a distance between adjacent lens units changes during focusing,
- wherein the second lens unit moves during the focusing, and
- wherein the following conditional expression is satisfied:
- −0.20<f3/f<−0.05
- where f is a focal length of the optical system focused on an object at infinity and f3 is a focal length of the third lens unit.
Dependencies are inferred from the claim text.