Accumulation time control device for photoelectric conversion element, and focus detection apparatus using the same

摘要

In order to realize focus detection using distance measurement areas more than the prior art without increasing the circuit scale, an accumulation control device has an AF sensor driving device SDR, which has i accumulation controllers that are fewer than the number j of photoelectric conversion element arrays and independently perform accumulation control of photoelectric conversion element arrays SNS-1A and SNS-1B to SNS-jA and SNS-jB in units of arrays in accordance with accumulation monitor signals, and a multiplexer DETMPX for selectively switching the accumulation monitor signals to be supplied from the photoelectric conversion element arrays to the accumulation controllers via signal lines BMON1 to BMONi. Photoelectric conversion element arrays equal to the number i of accumulation controllers are selected from the j photoelectric conversion element arrays, and accumulation control is done using only the accumulation control signals output from the selected photoelectric conversion element arrays. Focus adjustment can be performed by freely selecting an arbitrary distance measurement point from a broad distance measurement area without increasing the circuit scale of the accumulation controllers.