Imaging device and focusing control method

An imaging device comprising:

• an imaging element that includes a pair line in which a plurality of pairs of a first signal detection pixel that detects a signal corresponding to a beam that passes through a divided region among divided regions of a pupil region divided in a specific direction in an imaging optical system and a second signal detection pixel that detects a signal corresponding to a beam that passes through the other divided region is arranged in the specific direction, in which the plurality of pair lines is arranged in a direction orthogonal to the specific direction;
• and
• at least one of processors configured to
• generate a defocus amount from a result of a correlation operation performed with respect to a plurality of detection signals obtained by adding up detection signals of the plurality of first signal detection units in an arbitrary pair line present in an area where the plurality of pair lines is arranged and detection signals of the first signal detection pixels in a different pair line in the area, present in a crossing direction crossing the specific direction with respect to each of the plurality of respective first signal detection pixels, and a plurality of detection signals obtained by adding up detection signals of the second signal detection pixels that forms pairs in combination with each of the plurality of first signal detection pixels in the arbitrary pair line and detection signals of the second signal detection pixels in the different pair line in the area, present in the crossing direction with respect to the second signal detection pixels;
• determine a direction where a reliability of the result of the correlation operation becomes a maximum among a plurality of directions as the crossing direction;
• and
• perform a focusing control for the imaging optical system based on the generated defocus amount from the result of the correlation operation performed using the determined direction as the crossing direction.