초록 ▼

A method and apparatus for determining the direction the taking lens of a camera should be moved in order to provide a proper focus condition. A plurality of radiant energy detectors are positioned to receive energy from a scene being viewed and a first group of such detectors produces a first outpu

A method and apparatus for determining the direction the taking lens of a camera should be moved in order to provide a proper focus condition. A plurality of radiant energy detectors are positioned to receive energy from a scene being viewed and a first group of such detectors produces a first output signal pattern while a second group of such detectors produces a second output signal pattern. The two patterns coincide at the desired focus position but move with respect to one another in a first or opposite direction depending upon the focus condition. The slope of one or both of the patterns at predetermined positions is multiplied by the difference in value from the outputs of the detectors to create values which are summed. The sign of the summed values is representative of the direction the taking lens must be moved to bring the patterns into coincidence at the desired focus position.

대표청구항 ▼

Apparatus for use with an auto focus system which includes lens means that produces first and second radiation patterns of a scene, and first radiation detector means responsive to the first radiation pattern to produce a first output signal in accordance therewith and second radiation detector mean

Apparatus for use with an auto focus system which includes lens means that produces first and second radiation patterns of a scene, and first radiation detector means responsive to the first radiation pattern to produce a first output signal in accordance therewith and second radiation detector means responsive to the second radiation pattern to produce a second output signal in accordance therewith, said first and second output signals being similar and in a first position with respect to each other when the lens means is at a proper focus position, the first and second output signals moving away from the first position in a first direction when the lens means moves away from the proper focus position on a first side, the first and second output signals moving away from the first position in a second direction opposite to the first direction when the lens means moves away from the proper focus position on a second side opposite to the first side, the improvement comprising: means detecting the slope of a portion of at least one of the first and second output signals and producing a first resultant signal in accordance therewith; means detecting the difference in magnitude of the first and second output signals and producing a second resultant signal in accordance therewith; and further means receiving the first resultant signal and the second resultant signal to produce a product signal which has a first sign when the first and second output signals are away from the first position in the first direction and which has a second sign when the first and second output signals are away from the first position in the second direction.