Two-sided optical recording medium

Abstract From the Canadian patent

The novel optical recording medium as in the, prior art, has a transparent substrate bearing two recording layers, each addressable from only one side of the medium, but unlike prior 2-sided media the two, recording layers are on the same face of the substrate. when the novel medium is addressed from one side of the substrate, a thin-film barrier, such as an opaque metal between the two recording layers prevents the more distant recording layer from responding to that energy. Preferably a tough, transparent cover layer is sealed to the substrate to protect the two recording layers.