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US 8,135,269 B2Granted
Image pickup apparatus
AssigneeCanon Kabushiki Kaisha
InventorsGoro Noto, Shinji Imada
Life of this patent
Estimating the term…
Abstract
An optical device includes a shooting optical system including an AF lens, an AF lens driving apparatus for driving the AF lens, a detection unit for detecting a defocus amount corresponding to a difference between an image pickup position of an object and an imaging position of the object which is formed by the shooting optical system, and a control unit for drive-controlling the AF lens driving apparatus to reduce the defocus amount. The control unit detects a shooting magnification of the shooting optical system and changes a method of controlling the AF lens driving apparatus to reduce the defocus amount based on the shooting magnification.
Claims5
An image pickup apparatus, comprising:
- a magnification information obtaining unit for obtaining information including a shooting magnification of a shooting optical system;
- a control unit for performing focus control on the shooting optical system;
- and
- a detection unit for detecting a defocus amount corresponding to a difference between an image pickup position of an object and an imaging position of the object which is formed by the shooting optical system,
- wherein the control unit repeats the focus control even after an in-focus state of the shooting optical system is obtained by the focus control, and
- wherein when the shooting magnification is equal to or larger than a predetermined value, the control unit sets a sampling frequency for detecting the defocus amount to a value larger than in a case where the shooting magnification is smaller than the predetermined value.
3 more elements
An image pickup apparatus, comprising:
- a magnification information obtaining unit for obtaining information including a shooting magnification of a shooting optical system;
- a control unit for performing focus control on the shooting optical system;
- and
- a detection unit for detecting a defocus amount corresponding to a difference between an image pickup position of an object and an imaging position of the object which is formed by the shooting optical system,
- wherein the control unit estimates an imaging position of the object in the future based on an imaging position of the object in the past and repeats the focus control even after an in-focus state of the shooting optical system is obtained by the focus control so as to reduce the defocus amount with respect to the imaging position of the object in the future based on the imaging position of the object in the future which is estimated, and
- wherein when the shooting magnification is equal to or larger than a predetermined value, the control unit sets a number of data of the imaging position of the object in the past which are used to estimate the imaging position of the object in the future, the number being smaller than a number of data of the imaging position of the object in the past in a case where the shooting magnification is smaller than the predetermined value.
3 more elements
An image pickup apparatus, comprising:
- a magnification information obtaining unit for obtaining information including a shooting magnification of a shooting optical system;
- a control unit for performing focus control on the shooting optical system;
- and
- a detection unit for detecting a defocus amount corresponding to a difference between an image pickup position of an object and an imaging position of the object which is formed by the shooting optical system,
- wherein when the shooting magnification is equal to or larger than a predetermined value, the control unit repeats the focus control even after an in-focus state of the shooting optical system is obtained by the focus control so as to reduce the defocus amount with respect to an imaging position of the object in the past without estimating an imaging position of the object in the future, and
- wherein when the shooting magnification is smaller than the predetermined value, the control unit estimates the imaging position of the object in the future based on the imaging position of the object in the past and repeats the focus control even after the in-focus state of the shooting optical system is obtained by the focus control so as to reduce the defocus amount with respect to the imaging position of the object in the future based on the imaging position of the object in the future which is estimated.
3 more elements
Dependencies are inferred from the claim text.