Patent ID: 8971697
Filing Date: 2015-03-03
Classification: G02B,G03B,H04N

Abstract:
1. A focus detection apparatus for detecting a focus state of an imaging lens comprising: a photoelectric converter configured to photoelectrically convert a pair of light fluxes from an object through a pair of line sensors to output electrical signals; a memory configured to store the electrical signals read out from the photoelectric converter; a control unit configured to sequentially monitor, while observing charge accumulation for, each pair of blocks in a plurality of pairs of blocks that are set by dividing the pair of line sensors in a first pattern, and to read out the electrical signals from the each pair of blocks to the memory on condition that the electrical signals suitable for focus state detection is observed, and to sequentially monitor, while observing charge accumulation for, each pair of blocks in a plurality of pairs of blocks that are set by dividing the pair of line sensors in a second pattern, and to read out the electrical signals from the each pair of blocks to the memory on condition that the electrical signals suitable for focus state detection is observed, wherein the monitoring of the plurality of pairs of blocks in the first pattern and the monitoring of the plurality of pairs of blocks in the second pattern are alternately repeated, and wherein the blocks in the second pattern includes boundaries of the blocks in the first pattern and the blocks in the first pattern includes boundaries of the blocks in the second pattern; and a focus detection unit configured to detect a focus state of the imaging lens on the object with each pairs of blocks as a focus detection point, on the basis of a phase difference between electrical signals of the pairs of the divided blocks stored in the memory.