AF camera system

An AF camera system for automatically controlling photographing lens for focusing an object comprising:

• first focus detection means for detecting a focusing condition of said photographing lens with respect to said object, and for producing a focusing signal based on the detected result;
• infocus condition detection means for detecting, based on said focusing signal, an infocus condition of said photographing lens with respect to said object;
• focus adjusting means for prohibiting, under a first mode, the lens movement regardless of the detected focusing condition after the detection of infocus condition by said infocus condition detection means, and for adjusting the photographing lens, under a second mode, based on the detected focusing condition even after the detection of infocus condition;
• judging means for judging whether or not an object is moving;
• and
• selecting means for automatically selecting one of said first and second modes of said focus adjusting means based on a result of judgment.

An AF camera system for automatically controlling a photographing lens for focusing an object comprising:

• first focus detection means for detecting a focusing condition of said photographing lens with respect to said object, and for producing a focusing signal based on the detected result;
• infocus condition detection means for detecting, based on said focusing signal, an infocus condition of said photographing lens with respect to said object;
• object condition detecting means for detecting, after the detection of infocus condition by said infocus condition detection means, the condition of said object by the input of said focusing signals obtained at a plurality of times, and for producing an object condition signal;
• focus adjusting means for prohibiting, under a first mode, the lens movement regardless of the detected focusing condition, and for adjusting the photographing lens, under a second mode, based on the detected focusing condition;
• and
• selecting means for selecting one of said first and second modes of said focus adjusting means.

An AF camera system for automatically controlling an objective lens for focusing an object comprising:

• a focus detection means for generating a defocus data DF carrying information of a defocus amount and a defocus direction based on a focus condition of an object to be focused through an objective lens detected in a detection cycle;
• an infocus detection means for detecting an infocus condition based on the defocus data;
• a lens drive means for driving the objective lens based on the defocus amount and defocus direction carried in the defocus data DF when the infocus detection means did not detect the infocus condition;
• and
• a control means for controlling the focus adjustment such that a focus adjustment operation mode is changed from a first mode to a second mode in response to the detection of the infocus condition detected by the infocus detection means, wherein said control means comprises a selecting means for selecting a focus adjustment mode based on a plurality of focus detection results obtained by said focus detection means during stopping of the lens after obtaining an infocus condition, wherein said selecting means selects, when a focus detection after an infocus condition has been obtained shows an unexpected result which is either one of an unexpectedly great defocus amount or a focus detection failure, a focus lock mode in which the lens is locked once it has been shifted to a position to obtain an infocus condition.