| 摘要 |
<p>In a method and apparatus of identifying a document with the aid of at least two different types of optically readable markings disposed on the document, and of at least two light sensors, each individual marking modifying light impinging thereon in a characteristic manner, and wherein each light sensor is associated with a respective marking, and senses the light modified by the associated marking, the steps include placing the markings in a predetermined cyclical sequence on at least one track of the document, so as to avoid the creation of any optically readable gap, thereafter erasing at least selected portions of the markings, while maintaining in selected groups of two adjacent markings at least a portion of one of the markings in dependence of coded information to be recorded on the document, obtaining a timing signal from the light sensors in dependence of the light modified by the markings, with the aid of the timing signal, serially reading out the coded information from the marking portions remaining on the document, and examining the read-out coded information from the remaining marking portions on the document.</p> |
