IMAGE CAPTURING APPARATUS AND METHOD OF CONTROLLING THE SAME

摘要

An image capturing apparatus having an image sensor including focus detection pixels capable of outputting a pair of image signals for focus detection determines whether each line of the pixels of the image sensor is an addition/non-addition line that outputs the image signal suitable/unsuitable for detection of a correlation amount, obtains the correlation amount for each addition line based on the pair of image signals, add the obtained correlation amount of the addition line, counts the number of addition lines, obtains a defocus amount based on the added correlation amount, and drives a focus lens based on the defocus amount when a product of an evaluation value representing reliability of the defocus amount and a predetermined standard number of additions is smaller than the product of the number of addition lines and a standard evaluation value representing a predetermined evaluation value.

主权项

1. An image capturing apparatus comprising:
an image sensor including a plurality of pixels that are two-dimensionally arranged and include focus detection pixels including photoelectric conversion units configured for outputting a pair of image signals obtained by receiving a pair of light beams that have passed through different exit pupil regions of an imaging optical system; a determination unit configured to determine whether each line of the pixels of said image sensor is an addition line that outputs the image signal suitable for detection of a correlation amount; a calculation unit configured to, while shifting, with respect to each other, the pair of image signals output from the focus detection pixels in each addition line by a predetermined amount, calculate a correlation amount between the pair of image signals at each shift amount for each addition line, add a plurality of correlation amounts, that are calculated for each of the addition lines, for each shift amount, and obtain a minimum added correlation amount that is a minimum value of the plurality of added correlation amounts added for each shift amount; a counting unit configured to count the number of addition lines added by the calculation unit; a computing unit configured to obtain a defocus amount based on the minimum added correction amount; and a focus control unit configured to drive a focus lens included in the imaging optical system based on the defocus amount in a case where an evaluation value obtained based on the minimum added correction amount and the number of addition lines counted by the counting unit is higher than a predetermined value.