Focus detection apparatus and method, image capturing apparatus, and lens unit

An image capturing apparatus comprising:

• an image sensor that photoelectrically converts light that has entered via an imaging optical system into an image signal and outputs the image signal;
• and
• a focus detection apparatus that comprises:
• a focus detection unit that detects an in-focus position using the image signal obtained by the image sensor;
• a first acquisition unit that acquires aberration information of the imaging optical system;
• a generating unit that generates a recording image using the image signal obtained from the image sensor;
• a calculation unit that calculates, on the basis of the aberration information, a correction value for correcting a difference between the in-focus position detected by the focus detection unit and a position to be focused on in the recording image;
• and
• a correction unit that corrects the in-focus position using the correction value,
• wherein the calculation unit calculates the correction value on the basis of information of a display unit that displays an image based on the image signal.

A lens unit comprising:

• an input unit that inputs an in-focus position of a focus lens, the in-focus position being detected using an image signal obtained by an image sensor photoelectrically converting light that has entered via an imaging optical system including the lens unit having the focus lens;
• a first acquisition unit that acquires first weighting information corresponding to a state of aberration of the imaging optical system occurring when an image based on the image signal is displayed in a display unit and viewed;
• a second acquisition unit that acquires second weighting information corresponding to a state of aberration of the imaging optical system occurring when the in-focus position is detected;
• a calculation unit that calculates a correction value, for correcting the in-focus position, from the aberration information of the imaging optical system, the first weighting information, and the second weighting information;
• a correction unit that corrects the in-focus position using the correction value;
• and
• a driving unit that drives the focus lens on the basis of the corrected in-focus position,
• wherein the first acquisition unit acquires the first weighting information on the basis of image capturing conditions of the image signal and viewing conditions of the image.

A focus detection method comprising:

• detecting an in-focus position using an image signal obtained by an image sensor photoelectrically converting light that has entered via an imaging optical system;
• acquiring aberration information of the imaging optical system;
• generating a recording image using the image signal obtained from the image sensor;
• calculating, on the basis of the aberration information, a correction value for correcting a difference between the detected in-focus position and a position to be focused on in the recording image;
• correcting the in-focus position using the correction value;
• and
• calculating the correction value on the basis of information of a display unit that displays an image based on the image signal.

A focus detection method comprising:

• inputting an in-focus position of a focus lens, the in-focus position being detected using an image signal obtained by an image sensor photoelectrically converting light that has entered via an imaging optical system including a lens unit having the focus lens;
• acquiring first weighting information corresponding to a state of aberration of the imaging optical system occurring when an image based on the image signal is displayed in a display unit and viewed;
• acquiring second weighting information corresponding to a state of aberration of the imaging optical system occurring when the in-focus position is detected;
• calculating a correction value, for correcting the in-focus position, from the aberration information of the imaging optical system, the first weighting information, and the second weighting information;
• correcting the in-focus position using the correction value;
• and
• acquiring the first weighting information on the basis of image capturing conditions of the image signal and viewing conditions of the image.

A computer-readable storage medium on which is stored a program for causing a computer to execute the steps of the focus detection method, comprising:

• detecting an in-focus position using an image signal obtained by an image sensor photoelectrically converting light that has entered via an imaging optical system;
• acquiring aberration information of the imaging optical system;
• generating a recording image using the image signal obtained from the image sensor;
• calculating, on the basis of the aberration information, a correction value for correcting a difference between the detected in-focus position and a position to be focused on in the recording image;
• correcting the in-focus position using the correction value;
• and
• calculating the correction value on the basis of information of a display unit that displays an image based on the image signal.

A computer-readable storage medium on which is stored a program for causing a computer to execute the steps of the focus detection method, comprising:

• inputting an in-focus position of a focus lens, the in-focus position being detected using an image signal obtained by an image sensor photoelectrically converting light that has entered via an imaging optical system including a lens unit having the focus lens;
• acquiring first weighting information corresponding to a state of aberration of the imaging optical system occurring when an image based on the image signal is displayed in a display unit and viewed;
• acquiring second weighting information corresponding to a state of aberration of the imaging optical system occurring when the in-focus position is detected;
• calculating a correction value, for correcting the in-focus position, from the aberration information of the imaging optical system, the first weighting information, and the second weighting information;
• correcting the in-focus position using the correction value;
• and
• acquiring the first weighting information on the basis of image capturing conditions of the image signal and viewing conditions of the image.