| 摘要 |
An optical code recognition unit (OCRU) for recognising a predetermined n-bit optical code has an n-way splitter (7) having an input and n parallel outputs (7a). A plurality of cominbers (8a, 8b, 8c) are associated with the splitter outputs (7a), and a respective gate (9a, 9b, 9c) is controlled by the output of each of the combiners. Each of the splitter outputs (7a) is subject to a different delay of from 0 to (n-1) bit periods, and each combiner (8a, 8b, 8c) receives an input from at least one of the splitter outputs (7a). The OCRU is such that all the gates (9a, 9b, 9c) are turned on if a predetermined optical code is applied to the splitter input. |
