초록 ▼

Apparatus for determining the direction a lens should be moved in order to provide a proper focus of a remote object on a predetermined plane. A plurality of radiation detectors are positioned to receive radiation in first and second patterns from the object and to produce signals in accordance ther

Apparatus for determining the direction a lens should be moved in order to provide a proper focus of a remote object on a predetermined plane. A plurality of radiation detectors are positioned to receive radiation in first and second patterns from the object and to produce signals in accordance therewith. A first group of radiation detectors, produces signals indicative of the radiation received on the first pattern while a second group of radiation detectors produces signals indicative of the radiation received, in the second pattern. The two patterns coincide at the proper focus but at other than the proper focus position, the two patterns are spaced from one another in a direction which depends upon the direction the lens should be moved to achieve proper focus. The absolute value of the difference between the signal from a first detector in the first pattern and the signal from a first detector in the second pattern is compared with the absolute value of the difference between the signal from a second detector in the first pattern and the signal from a second detector in the second pattern. The result is summed over a predetermined range and a characteristic of the summed value is indicative of the direction the lens should be moved for proper focus.

대표청구항 ▼

Apparatus for use with an auto focus system which includes lens means that produces first and second radiation patterns of a scene, the patterns being similar and in a relative first condition when the lens means is in a proper focus position, in a relative second condition when the lens means is on

Apparatus for use with an auto focus system which includes lens means that produces first and second radiation patterns of a scene, the patterns being similar and in a relative first condition when the lens means is in a proper focus position, in a relative second condition when the lens means is on a first side of the proper focus position and in a relative third condition when the lens means is on a second side of the proper focus position comprising, in combination; a first radiation detector positioned to receive radiation corresponding to a first position in the first pattern and to produce a first signal in accordance therewith; a second radiation detector positioned to receive radiation corresponding to a second position in the first pattern and to produce a second signal in accordance therewith; a third radiation detector positioned to receive radiation corresponding to a first position in the second pattern and to produce a third signal in accordance therewith; a fourth radiation detector positioned to receive radiation corresponding to a second position in the second pattern and to produce a fourth signal in accordance therewith; and signal receiving means connected to said first, second, third and fourth detectors to receive the first, second, third and fourth signals respectively therefrom and to produce a resultant signal representative of the absolute value of the difference between the first signal and the fourth signal less the absolute value of the difference between the second signal and the third signal, the resultant signal having a first characteristic when the patterns are in the relative second condition and having a second characteristic when the patterns are in the relative third condition, as an indication of lens being on the first or second side respectively of the proper focus position.