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US 9,338,344 B2Granted
Focusing apparatus and method for controlling the same, and image pickup apparatus
AssigneeCanon Kabushiki Kaisha
InventorShun Nakamura
Life of this patent
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Abstract
The defocus amount of an imaging optical system is detected based on a pair of image signals that are obtained from an image sensor and are used for phase-difference detection automatic focusing. In a first mode, the drive of a focusing lens is controlled so that the focusing lens is driven at a first speed if the reliability of the pair of image signal is at a first level, and at a second speed lower than the first speed if the reliability of the pair of image signals is at a second level higher than the first level.
Claims45
A focusing apparatus comprising:
- an image sensor configured to generate a pair of image signals used for focus state detection by phase-difference detection method;
- a calculation unit configured to calculate a first value based on a coincidence degree of the pair of image signals, wherein the first value indicates reliability of the pair of image signals;
- a detection unit configured to detect a focus state based on the pair of image signals;
- and
- a control unit configured to control drive of a focusing lens based on the focus state detected by the detection unit,
- wherein, when the first value indicates that the reliability of the pair of image signals is higher than predetermined reliability, the control unit controls the focusing lens in a first mode in which the focusing lens is driven at a first speed if the first value indicates that the reliability of the pair of image signals is at a first level, and at a second speed lower than the first speed if the first value indicates that the reliability of the pair of image signals is at a second level higher than the first level,
- wherein the focus state includes a defocus direction and the predetermined reliability corresponds to reliability indicating that a defocus direction detected by the detection unit is reliable.
4 more elements
An image pickup apparatus comprising:
- a focusing apparatus comprising:
- an image sensor configured to generate a pair of image signals used for focus state detection by phase-difference detection method;
- a calculation unit configured to calculate a first value based on a coincidence degree of the pair of image signals, wherein the first value indicates reliability of the pair of image signals;
- a detection unit configured to detect a focus state based on the pair of image signals;
- and
- a control unit configured to control drive of a focusing lens based on the focus state detected by the detection unit,
- wherein, when the first value indicates that the reliability of the pair of image signals is higher than predetermined reliability, the control unit controls the focusing lens in a first mode in which the focusing lens is driven at a first speed if the first value indicates that the reliability of the pair of image signals is at a first level, and at a second speed lower than the first speed if the first value indicates that the reliability of the pair of image signals is at a second level higher than the first level,
- wherein the focus state includes a defocus direction, and the predetermined reliability corresponds to reliability indicating that a defocus direction detected by the detection unit is reliable, and
- wherein
- the image sensor generates an image signal for displaying or recording.
7 more elements
A method for controlling a focusing apparatus including an image sensor configured to generate a pair of image signals used for focus state detection by phase-difference detection method, the method comprising:
- calculating a first value based on a coincidence degree of the pair of image signals, wherein the first value indicates reliability of the pair of image signals;
- detecting a focus state based on the pair of image signals;
- and
- controlling drive of a focusing lens based on the focus state detected by the detecting,
- wherein, in the controlling, when the first value indicates that the reliability of the pair of image signals is higher than predetermined reliability, the focusing lens is controlled so as to be driven at a first speed if the first value indicates that the reliability of the pair of image signals is at a first level, and at a second speed lower than the first speed if the first value indicates that the reliability of the pair of image signals is at a second level higher than the first level,
- wherein the focus state includes a defocus direction and the predetermined reliability corresponds to reliability indicating that a defocus direction detected by the detection unit is reliable.
3 more elements
A focusing apparatus comprising:
- a processor configured to perform the functions of a calculation unit, a detection unit, and a control unit;
- an image sensor configured to generate a pair of image signals used for focus state detection by phase-difference detection method;
- the calculation unit configured to calculate a first value based on a coincidence degree of the pair of image signals, wherein the first value indicates reliability of the pair of image signals;
- the detection unit configured to detect a focus state based on the pair of image signals;
- and
- the control unit configured to control drive of a focusing lens based on the focus state detected by the detection unit,
- wherein, when the first value indicates that the reliability of the pair of image signals is higher than predetermined reliability, the control unit controls the focusing lens in a first mode in which the focusing lens is driven at a first speed if the first value indicates that the reliability of the pair of image signals is at a first level, and at a second speed lower than the first speed if the first value indicates that the reliability of the pair of image signals is at a second level higher than the first level,
- wherein the focus state includes a defocus direction and the predetermined reliability corresponds to reliability indicating that a defocus direction detected by the detection unit is reliable.
5 more elements
An image pickup apparatus comprising:
- a focusing apparatus comprising:
- a processor configured to perform the functions of a calculation unit, a detection unit, and a control unit;
- an image sensor configured to generate a pair of image signals used for focus state detection by phase-difference detection method;
- the calculation unit configured to calculate a first value based on a coincidence degree of the pair of image signals, wherein the first value indicates reliability of the pair of image signals;
- the detection unit configured to detect a focus state based on the pair of image signals;
- and
- the control unit configured to control drive of a focusing lens based on the focus state detected by the detection unit,
- wherein, when the first value indicates that the reliability of the pair of image signals is higher than predetermined reliability, the control unit controls the focusing lens in a first mode in which the focusing lens is driven at a first speed if the first value indicates that the reliability of the pair of image signals is at a first level, and at a second speed lower than the first speed if the first value indicates that the reliability of the pair of image signals is at a second level higher than the first level,
- wherein the focus state includes a defocus direction, and the predetermined reliability corresponds to reliability indicating that a defocus direction detected by the detection unit is reliable, and
- wherein the image sensor generates an image signal for displaying or recording.
7 more elements
A method for controlling a focusing apparatus including an image sensor configured to generate a pair of image signals used for focus state detection by phase-difference detection method, the method comprising:
- calculating a first value based on a coincidence degree of the pair of image signals, wherein the first value indicates reliability of the pair of image signals;
- detecting a focus state based on the pair of image signals;
- and
- controlling drive of a focusing lens based on the focus state detected by the detecting,
- wherein, in the controlling, when the first value indicates that the reliability of the pair of image signals is higher than predetermined reliability, the focusing lens is controlled so as to be driven at a first speed if the first value indicates that the reliability of the pair of image signals is at a first level, and at a second speed lower than the first speed if the first value indicates that the reliability of the pair of image signals is at a second level higher than the first level,
- wherein the focus state includes a defocus direction and the predetermined reliability corresponds to reliability indicating that a defocus direction detected by the detection unit is reliable.
3 more elements
A focusing apparatus comprising:
- an image sensor configured to generate a pair of image signals used for focus state detection by phase-difference detection method;
- a calculation unit configured to calculate a first value based on a coincidence degree of the pair of image signals, wherein the first value indicates reliability of the pair of image signals;
- a detection unit configured to detect a focus state based on the pair of image signals;
- and
- a control unit configured to control drive of a focusing lens based on the focus state detected by the detection unit,
- wherein the control unit controls the drive of the focusing lens so that a drive speed decreases in stages as the reliability of the pair of image signals indicated by the first value becomes better.
3 more elements
An image pickup apparatus comprising:
- a focusing apparatus comprising:
- an image sensor configured to generate a pair of image signals used for focus state detection by phase-difference detection method;
- a calculation unit configured to calculate a first value based on a coincidence degree of the pair of image signals, wherein the first value indicates reliability of the pair of image signals;
- a detection unit configured to detect a focus state based on the pair of image signals;
- and
- a control unit configured to control drive of a focusing lens based on the focus state detected by the detection unit,
- wherein the control unit controls the drive of the focusing lens so that a drive speed decreases in stages as the reliability of the pair of image signals indicated by the first value becomes better, and
- wherein the image sensor generates an image signal for displaying or recording.
5 more elements
A method for controlling a focusing apparatus including an image sensor configured to generate a pair of image signals used for focus state detection by phase-difference detection method, the method comprising:
- calculating a first value based on a coincidence degree of the pair of image signals, wherein the first value indicates reliability of the pair of image signals;
- detecting a focus state based on the pair of image signals;
- and
- controlling drive of a focusing lens based on the focus state detected by the detecting,
- wherein, in the controlling, the drive of the focusing lens is controlled so that a drive speed decreases in stages as the reliability of the pair of image signals indicated by the first value becomes better.
2 more elements
Dependencies are inferred from the claim text.