US Patent No. 9,444,993

FOCUS DETECTING APPARATUS, LENS APPARATUS INCLUDING THE SAME, IMAGE PICKUP APPARATUS, AND METHOD OF DETECTING DEFOCUS AMOUNT


Patent No. 9,444,993
Issue Date September 13, 2016
Title Focus Detecting Apparatus, Lens Apparatus Including The Same, Image Pickup Apparatus, And Method Of Detecting Defocus Amount
Inventorship Katsumi Karasawa, Utsunomiya (JP)
Assignee CANON KABUSHIKI KAISHA, Tokyo (JP)

Claim of US Patent No. 9,444,993

1. A focus detecting apparatus comprising:
a pair of sensors;
a read out controller configured to set a range of pixels to be calculated for each of the pair of sensors based on an image
displacement amount in a longitudinal direction of the pair of sensors between a pair of image signals obtained from the pair
of sensors in a state of being in focus on a predetermined object;

a correlation calculator configured to calculate a correlation amount between the pair of image signals obtained from the
pair of sensors set as the range of pixels to be calculated by the read out controller; and

a defocus amount calculator configured to calculate a defocus amount based on the correlation amount,
wherein the read out controller sets, as one of the pixel regions, a range of pixels excluding a number of pixels corresponding
to the image displacement amount from one end based on the image displacement amount, and sets, as another of the pixel regions,
a range of pixels excluding the number of pixels corresponding to the image displacement amount from an end opposite to the
one end.