Method and apparatus for counting overlapping obects
AssigneeQuantity & Time Management Systems Limited
InventorsDavid L. Sparling, Andrew D. Gardner
Life of this patent
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Abstract
Apparatus and a method for counting primarily printed copy being advanced along a path in an overlapping manner is arranged to direct two beams of infra-red radiation on to a predetermined region in the path of advancement of the copy. The two beams are distinguishable and are directed from positions respectively upstream and downstream of said region. Two detectors are disposed above said region, to receive radiation from two distincts areas respectively, both within said region, but spaced in the direction of the path of advancement of the copy. Suitable processing of the detector outputs, to determine the gradients of the said areas, allows the generation of a count signal as the leading edge of an object passes through said region.
Claims11
Apparatus for counting objects advanced along a path in an overlapping manner, which apparatus comprises:
- a first radiation source;
- a second radiation source;
- said first and second radiation sources each being adapted to direct radiation obliquely towards a single predefined region in said path of advancement of the objects to be counted;
- said first source being disposed upstream and said second source being disposed downstream of said region and the radiations from the two sources being similar but distinguishable;
- a first radiation detector;
- a second radiation detector;
- said first and second radiation detectors being disposed closely adjacent one another but spaced apart in the direction of the length of said path, to receive radiation reflected respectively from two distinct areas both within said pre-defined region but spaced in said direction of the length of said path;
- and
- analyser means arranged to act on the outputs of said two radiation detectors and to provide an object count signal dependent upon the rate of change with respect to unit path length of the reflected radiations as detected by the two detectors.
A method of counting objects advanced along a path in an overlapping manner, in which method first and second beams of radiation are directed on to a region disposed in said path of advancement of the objects, said first and second beams being distinguishable from one another and being directed to said region obliquely from positions respectively upstream and downstream thereof, radiation reflected from two areas within said region but separated along the length of said path is received by two detectors relatively closely spaced along the length of said path, and the outputs of said two detectors are analysed to determine the rate with respect to unit path length at which the detected reflected radiations change, a count signal being issued dependent thereon.
Dependencies are inferred from the claim text.