Optical unit for detecting a focus state

摘要

An optical unit for detecting a focus state. The optical unit has a focus detection zone restricting plate having a plurality of openings arranged in a first pattern in a vicinity of a predetermined focal plane on which an object image is formed. A sensor unit having a plurality of sensor sections is arranged in a second pattern, different to the first pattern, in a vicinity of an image reforming surface on which the object image is reformed. A plurality of mirrors deflect light transmitted through the plurality of openings arranged in the first pattern toward the plurality of sensor sections so as to have a direction identical to a direction of the second pattern of the plurality of sensor sections. The plurality of openings and the plurality of sensor sections are provided on a body of the optical unit. The plurality of mirrors are provided on members separate from the body of the optical unit. The reflecting surfaces of the plurality of mirrors are positioned by bringing the reflecting surfaces into contact with reference surfaces formed on the body of the optical unit.