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

1. A focus detection apparatus comprising:

a controller having a processor which executes instructions stored in a memory or having circuitry, the controller being configured to function as:

a focus detection unit that detects an in-focus position using an image signal obtained by an image sensor photoelectrically converting light that has entered via an imaging optical system;

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 second 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 on a display unit and viewed;

a third 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 a difference between the in-focus position detected by the focus detection unit and a position to be focused on in the recording image, on the basis of the aberration information, the first weighting information, and the second weighting information,

a correction unit that corrects the in-focus position using the correction value.

2. The focus detection apparatus according to claim 1 , wherein the second acquisition unit acquires the first weighting information on the basis of image capturing conditions of the image signal and viewing conditions of the image.

3. The focus detection apparatus according to claim 1 , wherein the second weighting information is determined on the basis of the image capturing conditions.

4. The focus detection apparatus according to claim 1 , wherein the image capturing conditions include an image capturing condition that changes in accordance with an image processing method.

5. The focus detection apparatus according to claim 2 , wherein the viewing conditions include at least one of a size of the display unit that displays the image, a resolution of the display unit, a display ratio of the display unit, a distance between the display unit and a viewer, and a value input by the viewer.

6. 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 controller having a processor which executes instructions stored in a memory or having circuitry, the controller being configured to function as:

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 second 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 on a display unit and viewed;

a third 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 a difference between the in-focus position detected by the focus detection unit and a position to be focused on in the recording image, on the basis of the aberration information, the first weighting information, and the second weighting information; and

a correction unit that corrects the in-focus position using the correction value.

7. 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 a 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.

8. The lens unit according to claim 7 , wherein the second weighting information is determined on the basis of the image capturing conditions.

9. The lens unit according to claim 7 , wherein the image capturing conditions include an image capturing condition that changes in accordance with an image processing method.

10. The lens unit according to claim 7 , wherein the viewing conditions include at least one of a size of the display unit that displays the image, a resolution of the display unit, a display ratio of the display unit, a distance between the display unit and a viewer, and a value input by the viewer.

11. 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;

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 on 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 a difference between the detected in-focus position and a position to be focused on in the recording image, on the basis of the aberration information, the first weighting information and the second weighting information; and

correcting the in-focus position using the correction value.

12. 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.

13. A non-transitory 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;

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 on 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 a difference between the detected in-focus position and a position to be focused on in the recording image, on the basis of the aberration information, the first weighting information and the second weighting information; and

correcting the in-focus position using the correction value.

14. A non-transitory 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, the first weighting information being acquired on the basis of image capturing conditions of the image signal and viewing conditions of the image;

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; and

correcting the in-focus position using the correction value.