Focus detection apparatus, control method therefor, and storage medium for use therewith
AssigneeCanon Kabushiki Kaisha
InventorTakeshi Ogawa
Life of this patent
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Abstract
Focus detection apparatuses, control methods, and storage mediums for use therewith are provided herein. In a focus detection apparatus, a difference amplification unit performs processing for amplifying a difference between an A-image signal and a B-image signal and a CPU determines whether or not a focus state is a false in-focus state on a basis of a result of a correlation calculation performed by a correlation calculation unit on the A-image signal and the B-image signal. The A-image signal and the B-image signal are output from an imaging sensor that receives a pair of luminous fluxes passing through different pupil areas of an imaging optical system.
Claims8
A focus detection apparatus, comprising:
- a memory that stores a program of instructions;
- and
- at least one processor that executes the program of instructions to cause the focus detection apparatus to:
- perform a first correlation calculation in accordance with a pair of image signals, which pair of image signals is based on an output of an imaging sensor that receives a pair of luminous fluxes passing through different pupil areas of an imaging optical system and performs photoelectric conversion to the pair of luminous fluxes;
- amplify a difference between a first image signal and a second image signal of the pair of image signals, and output a third image signal corresponding to the first image signal and a fourth image signal corresponding to the second image signal;
- and
- determine whether or not a focus state is a false in-focus state on a basis of a result of a second correlation calculation according to the third image signal and the fourth image signal.
A control method of a focus detection apparatus, the method comprising the steps of:
- performing a first correlation calculation in accordance with a pair of image signals, which pair of image signals is based on an output of an imaging sensor that receives a pair of luminous fluxes passing through different pupil areas of an imaging optical system and performs photoelectric conversion to the pair of luminous fluxes;
- amplifying a difference between a first image signal and a second image signal of the pair of image signals and outputting a third image signal corresponding to the first image signal and a fourth image signal corresponding to the second image signal;
- and
- determining whether or not a focus state is a false in-focus state on a basis of a result of a second correlation calculation according the third image signal and the fourth image signal.
A non-transitory storage medium storing at least one program that causes a computer to execute a control method of a focus detection apparatus, the method comprising:
- performing a first correlation calculation in accordance with a pair of image signals, which pair of image signals is based on an output of an imaging sensor that receives a pair of luminous fluxes passing through different pupil areas of an imaging optical system and performs photoelectric conversion to the pair of luminous fluxes;
- amplifying a difference between a first image signal and a second image signal of the pair of image signals and outputting a third image signal corresponding to the first image signal and a fourth image signal corresponding to the second image signal;
- and
- determining whether or not a focus state is a false in-focus state on a basis of a result of a second correlation calculation according the third image signal and the fourth image signal.
Dependencies are inferred from the claim text.