Method and apparatus for electrooptical measurement of the distance from light-reflecting objects

Claim 2

In an electrooptical apparatus for determining the distance between a given point and a selected portion of an object irrespective of uneven distribution of light intensity in such selected porion, a combination comprising an electric differential circuit including a first pair of photoelectric receivers which furnish identical output currents when the amount of radiant energy impinging thereon is the same and a second pair of photoelectric receivers which also furnish identical output currents when the amount of radiant energy impinging thereon is the same; first optical intercepting means for directing a first beam of radiant energy which is reflected from the selected portion of the object against said first pair of receivers; and second optical intercepting means for directing against said second pair of receivers a second beam of radiant energy which is also reflected from said selected portion of the object, said first and second beams being disposed in a first plane and said second beam being mirror symmetrical to said first beam with reference to a second plane which is normal to said first plane.

Claim 3

A combination as defined in claim 1, wherein the receivers of each of said pairs are closely adjacent to each other.

Claim 4

A combination as defined in claim 1, wherein said first pair of receivers and said first intercepting means are disposed mirror symmetrically to said second pair of receivers and said second intercepting means with reference to said second plane, said second plane extending between said first and second pairs of receivers.

Claim 5

A combination as defined in claim 1, wherein said circuit is a signal-generating bridge circuit having a first branch containing one receiver of each of said pairs and a second branch containing the other receiver of each of said pairs.

Claim 6

A combination as defined in claim 4, further comprising reversible electric motor means operative to change the distance between said receivers and said selected portion of the object in response to signals from said bridge circuit to thereby change the ratio of radiant energy which impinges on said receivers.

Claim 7

A combination as defined in claim 5, further comprising an objective lens movable by said motor means together with said receivers.

Claim 8

In a method of compensating for uneven distribution of light intensity in a selected portion of an object in electrooptical measurement of the distance between such selected portion of the object and a given point, the steps of intercepting a first beam of radiant energy which is reflected from the selected portion of the object; intercepting a second beam of radiant energy which is also reflected from the selected portion of the object and wherein the distribution of intensity is a mirror image of distribution of intensity in the first beam, Said first and second beams being disposed in a first plane and said second beam being mirror symmetrical to said first beam with reference to a second plane which is normal to said first plane; and simultaneously evaluating both such beams for electrooptical measurement of the distance between the selected portion of the object and the given point, including directing the first beam against a pair of first photoelectric receivers which furnish identical output currents when the amount of radiant energy impinging thereon is the same and directing the second light beam against a pair of second photoelectric receivers which also furnish identical output currents when the amount of radiant energy impinging thereon is the same, said second receivers being in a differential electric circuit with the first receivers.

Claim 9

In a method of compensating for uneven distribution of light intensity in a selected portion of an object in electrooptical measurement of the distance between such selected portion of the object and a given point, the steps of intercepting a first beam of radiant energy which is reflected from the selected portion of the object; intercepting a second beam of radiant energy which is also reflected from the selected portion of the object and wherein the distribution of intensity is a mirror image of distribution of intensity in the first beam, Said first and second beams being disposed in a first plane and said second beam being mirror symmetrical to said first beam with reference to a second plane which is normal to said first plane; and simultaneously evaluating both such beams for electrooptical measurement of the distance between the selected portion of the object and the given point, including directing the first beam against a pair of first photoelectric receivers which furnish identical output currents when the amount of radiant energy impinging thereon is the same and directing the second light beam against a pair of second photoelectric receivers which also furnish identical output currents when the amount of radiant energy impinging thereon is the same, said second receivers being in a differential electric circuit with the first receivers.

Claim 10

In a method as defined in claim 7, wherein said first photoelectric receivers are photoelectric resistors which are closely adjacent to each other.

Claim 11

In a method as defined in claim 7, wherein said second photoelectric receivers are photoelectric resistors which are closely adjacent to each other.

Claim 12

In a method as defined in claim 7, wherein each of said beams produces on the respective receivers a circular speck of light.