Optical system, image pickup apparatus, and lens apparatus
AssigneeCanon Kabushiki Kaisha
InventorToyokatsu Fujisaki
Life of this patent
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Abstract
An optical system includes, 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 positive refractive power. During focusing from infinity to a short distance, the first lens unit is fixed, and the second lens unit and the third lens unit are moved so that a distance between the second lens unit and the third lens unit changes. Predetermined conditions are satisfied.
Claims26
An optical system comprising, 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 positive refractive power,
- wherein a distance between adjacent lens units changes when focusing,
- wherein an aperture stop is disposed between the first lens unit and the second lens unit,
- wherein for focusing from infinity to a short distance, the first lens unit-is fixed, and the second lens unit and the third lens unit are moved so that a distance between the second lens unit and the third lens unit changes,
- wherein the first lens unit includes a plurality of negative lenses, and
- wherein the following inequalities are satisfied:
- 0.01<f1/f≤2.026
- 0.70<f2/f3<30.00
- where f is a focal length of the optical system in an in-focus state on infinity, and f1, f2, and f3 are focal lengths of the first lens unit, the second lens unit, and the third lens unit, respectively.
An image pickup apparatus comprising:
- an optical system;
- and
- an image sensor configured to receive an image formed by the optical system,
- wherein the optical system includes, 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 positive refractive power,
- wherein a distance between adjacent lens units changes when focusing,
- wherein an aperture stop is disposed between the first lens unit and the second lens unit,
- wherein for focusing from infinity to a short distance, the first lens unit is fixed, and the second lens unit and the third lens unit are moved so that a distance between the second lens unit and the third lens unit changes,
- wherein the first lens unit includes a plurality of negative lenses, and
- wherein the following inequalities are satisfied:
- 0.01<f1/f≤2.026
- 0.70<f2/f3<30.00
- where f is a focal length of the optical system in an in-focus state on infinity, and f1, f2, and f3 are focal lengths of the first lens unit, the second lens unit, and the third lens unit, respectively.
A lens apparatus comprising an optical system,
- wherein the optical system includes, 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 positive refractive power,
- wherein a distance between adjacent lens units changes when focusing,
- wherein an aperture stop is disposed between the first lens unit and the second lens unit,
- wherein for focusing from infinity to a short distance, the first lens unit is fixed, and the second lens unit and the third lens unit are moved so that a distance between the second lens unit and the third lens unit changes,
- wherein the first lens unit includes a plurality of negative lenses, and
- wherein the following inequalities are satisfied:
- 0.01<f1/f≤2.026
- 0.70<f2/f3<30.00
- where f is a focal length of the optical system in an in-focus state on infinity, and f1, f2, and f3 are focal lengths of the first lens unit, the second lens unit, and the third lens unit, respectively.
Dependencies are inferred from the claim text.