OPTICAL RECORD CARDS

摘要

63356-1707 An optical information storage card having a rectangular format and comprising (a) a surface having, on at least one side thereof, surface relief formations forming an optically machine readable information surface; and (b) a protection layer being in overlying juxtaposed relationship to the information surface. The substrate and the protection layer are transmissive to a selected range of electromagnetic radiation usable for optically reading the information surface. The information surface has a generally spiral or concentric format whereby the information surface can be read as the card is rotated round at least one axis.