Optical card having light-absorbing layer

Abstract From the Canadian patent

A technique of optical card having high information recording density. In the optical cards there are two types of optical cards having a read-only optical card and an additional recording optical card. Conventionally separate readers for reproduction have been used due to difference in light reflectivity. In this invention, a light-absorbing layer (50) having light absorbing ability with respect to reading light (300) is arranged between a card side upon which the reading light is incident and a reflective surface of a pattern (21) of an optical data recording section (20) so that the optical cards have interchangeability therebetween in reading.