BEDRUCKTER UND KODIERTER ANTWORTSCHEIN ZUR VERBREITUNG IN GROSSEN STÜCKZAHLEN UND VERFAHREN ZU DESSEN HERSTELLUNG

摘要

A method of simultaneously encoding successive groups of printed paper sheets or mass distributable material wherein the sheets (20) are provided with unperceptable and virtually invisible common code pattern (30) by laser means (70) which is supplied with a distinct series of coded pulse signals in synchronism with control pulses to produce a different optically-scannable coded hole pattern (30) on each group of printed sheets.