Multipoint autofocusing system

A multipoint autofocusing system having a plurality of light receiving devices each having a plurality of focus detection areas which receive light of object images and perform an integral operation in which said object light is converted to produce integrated electric charges, and first monitor means for monitoring integral values of each of said light receiving devices, the multipoint autofocusing system comprising:

• detecting means for detecting an integration time of each of said light receiving devices based upon a commencement of said integral operation;
• and,
• integration control means for controlling said integration times to stop said integral operation of one of said light receiving devices when said integration time of said one of said light receiving devices reaches a predetermined integral value, and for forcedly terminating said integral operation of all of said light receiving devices having integration times which have not reached said predetermined integral value after a maximum integration time t.sub.max has lapsed;
• wherein said integration control means determines a forced integral stop time using a formula defined by:
• t1.times.(predetermined integral value)
• wherein t1 represents a shortest integration time of said light receiving device which first reaches said predetermined integral value, said integration control means forcedly terminates said integral operation of all of said light receiving devices having integration times below said predetermined integral value after said lapse of said maximum integration time t.sub.max.