Rewritable optical information medium
AssigneeU.S. Philips Corporation
InventorsHarm A. Wierenga, Johannes C. N. Rijpers
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Abstract
A rewritable single-sided double layer optical information medium having a first recording stack with a phase change recording layer sandwiched between two dielectric layers. The recording stack is sufficiently transmissive to ensure proper reading/writing of the second recording stack. For this purpose, the recording stack includes a thin metal layer and a further dielectric layer. The laser beam can be focused on the first recording stack or on the second recording stack, thus doubling the storage capacity of the recording medium.
Claims10
An optical information medium for rewritable double layer recording using a laser-light beam, comprising:
- a substrate;
- a multitude of layers disposed on the same side of the substrate and including:
- a first recording stack including a phase change type recording layer sandwiched between two dielectric layers, and a transparent metal layer and a further dielectric layer on the side opposite the side of the first recording stack on which the laser-light beam is incident;
- a transparent spacer layer having a thickness larger than the depth of focus of the laser-light beam;
- and
- a second recording stack including a phase change type recording layer sandwiched between two dielectric layers, and a metal mirror layer on the side opposite to the side of the second recording stack on which the laser-light beam is incident.
Dependencies are inferred from the claim text.