OPTICAL READER CORRELATION CIRCUITAbstract of the DisclosureBar codes imprinted or otherwise applied to anobject are read and decoded by focusing light reflected fromthe code by means of an objective lens to an image intensifiertube. Light energy reflected from the code impinges on thephoto cathode of the image intensifier tube thereby causingan electron beam to generate a display on a phosphor screenwith the electron beam deflected to center the code imageon the phosphor screen. A fiber optic array channels lightfrom the phosphor screen to an array of zones of photo sensorseach zone having an output coupled to a correlation circuit.Output voltages from the correlation circuits are simultane-ously coupled to acquisition, tracking and reading logic.Initially, upon detecting the presence of a code on an object,the acquisition and tracking logic responds thereto to producedeflection voltages to the image intensifier tube to providecentering on the phosphor screen. Once centered, outputsfrom the correlation circuits are coupled to reading logicto generate an output waveform representative of the barcoded data.
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