| 主权项 |
1. An imaging device that includes an imaging element that images a subject through an imaging optical system including a focus lens, the imaging element including a first signal detection unit that detects a signal corresponding to one beam of a pair of beams that pass through different portions in a pupil region of the imaging optical system, and a second signal detection unit that detects a signal corresponding to the other beam of the pair of beams, and the imaging device comprising:
a focusing control unit that drives the focus lens to perform a focusing control for focusing on a main subject; a focus lens position generation unit that calculates a focus lens position which is a position of the focus lens where an image formation surface on which the main subject is image-formed and a light receiving surface of the imaging element match each other, based on a correlation operation result of a detection signal of the first signal detection unit and a detection signal of the second signal detection unit obtained by image capturing performed by the imaging element; a subject distance conversion unit that converts the focus lens position calculated by the focus lens position generation unit into a subject distance which is a distance between the main subject and the focus lens; a subject distance prediction unit that predicts, from the subject distance generated by the subject distance conversion unit and corresponding to each of plural times of image capturing that continue in a time series manner, a subject distance in image capturing performed subsequent to the last image capturing among the plural times of image capturing; a focus lens position prediction unit that predicts, from the focus lens position generated by the focus lens position generation unit and corresponding to each of the plural times of image capturing that continue in a time series manner, a focus lens position in the image capturing performed subsequent to the last image capturing among the plural times of image capturing; a storage unit that stores information about an arrangement interval of the first signal detection units or the second signal detection units in the imaging element; an F value acquisition unit that acquires information about an F value of the imaging optical system, and a maximum error information acquisition unit that acquires information about a maximum error with respect to the focus lens position generated by the focus lens position generation unit, wherein the maximum error information acquisition unit acquires the information about the maximum error by calculating the maximum error from the information about the arrangement interval stored in the storage unit and the information about the F value acquired by the F value acquisition unit, wherein the focusing control unit, as a focusing control performed before the image capturing performed subsequent to the last image capturing, based on the focus lens position generated by the focus lens position generation unit and corresponding to each of the plural times of image capturing that continue in a time series manner and the information about the maximum error, converts positions obtained respectively by adding and subtracting the maximum error to and from the focus lens position converted from the subject distance predicted by the subject distance prediction unit into subject distances by the subject distance conversion unit, selects a first focusing control which drives the focus lens according to the focus lens position predicted by the lens position prediction unit in a case where a difference between the two converted subject distances is greater than a threshold value, or selects a second focusing control which drives the focus lens according to the subject distance predicted by the subject distance prediction unit in a case where the difference is equal to or smaller than the threshold value. |
