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US 11,889,186 B2Granted
Focus detection device, focus detection method, and image capture apparatus
AssigneeCanon Kabushiki Kaisha
InventorsYuki Yoshimura, Koichi Fukuda
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Abstract
A focus detection device calculates a shift amount between a first focus detection signal and a second focus detection signal both generated based on a signal obtained from an image sensor. The device also calculates a conversion coefficient and applies the conversion coefficient to the shift amount to convert the shift amount into a defocus amount of an imaging optical system. The device calculates the conversion coefficient based on at least one of a pupil eccentricity amount and an incident pupil distance, both are dependent on an image height at a focus detection position.
Claims20
A focus detection device comprising:
- one or more processors that execute a program stored in a memory and thereby function as:
- a generation unit that generates a first focus detection signal and a second focus detection signal based on a signal obtained from an image sensor;
- a first calculation unit that calculates a shift amount between the first focus detection signal and the second focus detection signal;
- a second calculation unit that calculates a conversion coefficient for converting the shift amount into a defocus amount of an imaging optical system;
- and
- a detection unit that detects the defocus amount by applying the conversion coefficient to the shift amount,
- wherein the second calculation unit calculates the conversion coefficient based on at least one of a pupil eccentricity amount and an incident pupil distance, and
- wherein the pupil eccentricity amount and the incident pupil distance have values based on stored values having different values corresponding to coordinates in two or more of four quadrants of a pixel region of the image sensor.
5 more elements
The focus detection device according to 1,
- wherein the second calculation unit obtains the pupil eccentricity amount at a focus detection position by interpolating or extrapolating the stored values of pupil eccentricity amounts corresponding to the coordinates, to use the pupil eccentricity amount in the calculation of the conversion coefficient.
The focus detection device according to 1,
- wherein the second calculation unit obtains the incident pupil distance at a focus detection position by interpolating or extrapolating the stored values of incident pupil distances corresponding to the coordinates, to use the incident pupil distance in the calculation of the conversion coefficient.
An image capture apparatus, comprising:
- an image sensor;
- and
- a focus detection device that comprises:
- one or more processors that execute a program stored in a memory and thereby function as:
- a generation unit that generates a first focus detection signal and a second focus detection signal based on a signal obtained from an image sensor;
- a first calculation unit that calculates a shift amount between the first focus detection signal and the second focus detection signal;
- a second calculation unit that calculates a conversion coefficient for converting the shift amount into a defocus amount of an imaging optical system;
- and
- a detection unit that detects the defocus amount by applying the conversion coefficient to the shift amount,
- wherein the second calculation unit calculates the conversion coefficient based on at least one of a pupil eccentricity amount and an incident pupil distance, and
- wherein the pupil eccentricity amount and the incident pupil distance have values based on stored values having different values corresponding to coordinates in two or more of four quadrants of a pixel region of the image sensor,
- wherein focus of an imaging optical system is adjusted based on a defocus amount detected by the focus detection device.
9 more elements
A focus detection method executed by a focus detection device, the focus detection method comprising:
- generating a first focus detection signal and a second focus detection signal based on a signal obtained from an image sensor;
- calculating a shift amount between the first focus detection signal and the second focus detection signal;
- calculating a conversion coefficient for converting the shift amount into a defocus amount of an imaging optical system;
- and
- detecting the defocus amount by applying the conversion coefficient to the shift amount,
- wherein the calculating of the conversion coefficient includes calculating the conversion coefficient based on at least one of a pupil eccentricity amount and an incident pupil distance, and
- wherein the pupil eccentricity amount and the incident pupil distance have values based on stored values having different values corresponding to coordinates in two or more of four quadrants of a pixel region of the image sensor.
4 more elements
A non-transitory computer-readable medium storing a program that causes, when executed by a computer of a focus detection device, the computer to function as:
- a generation unit that generates a first focus detection signal and a second focus detection signal based on a signal obtained from an image sensor;
- a first calculation unit that calculates a shift amount between the first focus detection signal and the second focus detection signal;
- a second calculation unit that calculates a conversion coefficient for converting the shift amount into a defocus amount of an imaging optical system;
- and
- a detection unit that detects the defocus amount by applying the conversion coefficient to the shift amount,
- wherein the second calculation unit calculates the conversion coefficient based on at least one of a pupil eccentricity amount and an incident pupil distance, and
- wherein the pupil eccentricity amount and the incident pupil distance have values based on stored values having different values corresponding to coordinates in two or more of four quadrants of a pixel region of the image sensor.
4 more elements
Dependencies are inferred from the claim text.