Objects counting method e.g. for people in shop - using light beam array with detector thresholds determining count of overlapping objects

摘要

The method uses a typical installation of 40 light beams and detectors over a length of 100 cm. The diagram shows the progress of an object through the array of n detectors. In (b) the first detector is dark, and in (c) and (d) successive detectors are darkened. In (e) the first detector is not dark, triggering a test in which if the sequence of dark cells following the light cell is unbroken and of length greater than a threshold value V, a count pulse is generated. The length is also checked to see if it exceeds a second value m, in which case a second count pulse is generated, and likewise for increasing lengths. USE/ADVANTAGE - Counting systems for people and objects in general passing in possibly overlapping stream through detection area of light detector array.