Focus detection apparatus and image pickup apparatus that perform focus detection using phase difference method

摘要

A focus detection apparatus which is capable of estimating each of signals from a plurality of split PDs, which are included in a sum signal from split PDs, by performing a computation to thus detect saturation with respect to each split PD. With respect to each unit pixel cell having a plurality of PDs sharing one micro lens, saturation of a pixel signal read out in a non-destructive manner from one of the PDs is detected. Based on a first luminance signal and a sum pixel signal obtained by summing signals output from the PDs, another pixel signal output from another one of the PDs is estimated. Saturation of the estimated pixel signal is detected, and a second luminance signal is generated. Based on the first and second luminance signals, the amount of defocus for an optical unit is calculated.

主权项

1. A focus detection apparatus comprising:
a solid-state imaging device configured to have an array of a plurality of unit pixel cells each having a plurality of photoelectric converters sharing one micro lens; a first saturation detection unit configured to, with respect to each of the unit pixel cells, detect saturation of a pixel signal read out from one of the plurality of photoelectric converters; a first luminance signal generation unit configured to generate a first luminance signal from the pixel signal; an estimation unit configured to, based on the first luminance signal and a sum pixel signal obtained from the unit pixel cell having the plurality of photoelectric converters, estimate another pixel signal output from another one of the plurality of photoelectric converters; a second saturation detection unit configured to detect saturation of the another pixel signal estimated by said estimation unit; a second luminance signal generation unit configured to generate a second luminance signal from a the another pixel signal; and a focus detection processing unit configured to, based on the first luminance signal and the second luminance signal, calculate an amount of defocus for an optical system provided for the solid-state imaging device.