Patent ID: 8976289
Filing Date: 2015-03-10
Classification: G03B,H04N

Abstract:
1. An imaging device comprising: an imaging optical system; an imaging element in which a plurality of pixels including a first pixel and a second pixel are arranged in a two-dimensional manner, the first pixel receiving a light on a partial area biased to a predetermined direction from a light axis of a light flux passing an exit pupil of the imaging optical system, the first pixel arranged at interval of a predetermined number of pixels, and the second pixel arranged so as to be adjacent to the first pixel and receiving a light on a partial area biased to an opposite direction to the predetermined direction from the light axis of the light flux passing the exit pupil of the imaging optical system; a brightness acquisition unit configured to acquire a brightness of a subject; an imaging element drive unit configured to read signal charges from the plurality of pixels as a voltage signal, the imaging element drive unit configured to read and combine signal charges of a first number of adjacent first pixels and to read and combine signal charges of the first number of adjacent second pixels when reading signal charges from the first pixel and the second pixel; an arithmetic mean calculation unit configured to calculate an arithmetic mean of voltage signals, combined and read by the imaging element drive unit, of a second number of adjacent first pixels and to calculate an arithmetic mean of voltage signals, combined and read by the imaging element drive unit, of the second number of adjacent second pixels; an automatic focus adjustment unit configured to detect a phase difference between the arithmetic mean of the voltage signals of the second number of the adjacent first pixels and the arithmetic mean of the voltage signals of the second number of the adjacent second pixels, and to automatically perform a focus adjustment of the imaging optical system based on the phase difference; and a processing unit configured to increase the first number and decrease the second number as the brightness of the subject acquired by the brightness acquisition unit becomes lower.