| 摘要 |
Bar codes imprinted or otherwise applied to an object are read and decoded by focusing light reflected from the code by means of an objective lens to an image intensifier tube. Light energy reflected from the code impinges on the photo cathode of the image intensifier tube thereby causing an electron beam to generate a display on a phosphor screen with the electron beam deflected to center the code image on the phosphor screen. A fiber optic array channels light from the phosphor screen to an array of zones of photo sensors each zone having an output coupled to a correlation circuit. Output voltages from the correlation circuits are simultaneously 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 produce deflection voltages to the image intensifier tube to provide centering on the phosphor screen. Outputs from the correlation circuits are coupled to reading logic to generate an output waveform representative of the bar coded data. |
