Focus detection device, focus detection method, and image capture apparatus
AssigneeCanon Kabushiki Kaisha
InventorsYuki Yoshimura, Koichi Fukuda
Life of this patent
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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.
Claims13
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, both are dependent on an image height at a focus detection position.
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, both are dependent on an image height at a focus detection position,
- wherein focus of an imaging optical system is adjusted based on a defocus amount detected by the focus detection device.
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, both are dependent on an image height at a focus detection position.
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, both are dependent on an image height at a focus detection position.
Dependencies are inferred from the claim text.