Patent ID: 9019424
Filing Date: 2015-04-28
Classification: G02B,G03B,H04N

Abstract:
1. An image pickup apparatus including a photographing optical system containing a photographing lens and an image pickup element for photoelectrically converting an optical image of an object which enters through the photographing lens and outputting an image signal, comprising: a pupil division unit configured to restrict light of the optical image of the object which enters each pixel of the image pickup element, to light from a specific exit pupil area of the photographing lens; an image shift unit configured to decide a shift amount of the image signal corresponding to a predetermined focus evaluation position for every exit pupil area on the basis of a correspondence relation between each pixel of the image pickup element and the specific exit pupil area of the photographing lens, wherein the relation is restricted by the pupil division unit; an image generation unit configured to generate an image corresponding to the focus evaluation position by executing an arithmetic operation processing based on the shift amount decided by the image shift unit to the image signal; a contrast evaluation unit configured to calculate an evaluation value of a contrast of the image generated by the image generation unit and decide a contrast focus position on the basis of the contrast evaluation value; a correlation calculation unit configured to calculate an evaluation value of a correlation between images corresponding to different exit pupil areas in the generated image and decide a correlation focus position on the basis of the correlation evaluation value; a focus evaluation range decision unit configured to decide a range of the focus evaluation position where the image shift unit can decide the shift amount, on the basis of a structure of the image pickup element and the pupil division unit; and a focus evaluation unit configured to compare an absolute value of the range decided by the focus evaluation range decision unit and an absolute value of the correlation focus position decided by the correlation calculation unit, wherein the focus evaluation unit is configured to decide a focus evaluation value of the object on the basis of the decided correlation focus position and the decided contrast focus position decided in accordance with a result of the comparison.