Optical recording medium and method for manufacturing the same
AssigneeSony Corporation
InventorsMasatsugu Suwabe, Hiroshi Nakayama, Takahiro Igari, Teruyuki Ota
Life of this patent
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Abstract
An optical recording medium includes: a substrate having a first principal surface and a second principal surface; one or plural information signal layers formed on the first principal surface of the substrate for undergoing recording or reproduction of information signals upon irradiation with light; and a barrier layer formed on the second principal surface of the substrate for suppressing the gas release from the second principal surface of the substrate, wherein an area of a region exposing from the barrier layer of the second principal surface of the substrate is not more than 688 mm2.
Claims20
An optical recording medium comprising:
- a substrate having a first principal surface and a second principal surface;
- a first information signal layer on the first principal surface of the substrate configured to record or reproduce information signals upon irradiation with light;
- and
- a barrier layer on the second principal surface of the substrate that suppresses the release of gas from the second principal surface of the substrate,
- wherein the barrier layer is structured to expose a region of the second principal surface of the substrate, and
- wherein an area of the region is less than or equal to 6.2% of the second principal surface of the substrate.
A method for manufacturing an optical recording medium comprising the steps of:
- molding a substrate having a first principal surface and a second principal surface;
- forming a first information signal layer on the first principal surface of the substrate;
- forming an interlayer on the first information signal layer;
- forming a second information signal layer on the interlayer;
- and
- forming a barrier layer that suppresses the release of gas from the second principal surface of the substrate on the second principal surface of the substrate after molding the substrate and before forming the second information signal layer,
- wherein forming the barrier layer includes forming a region that exposes the second principal surface of the substrate, and
- wherein an area of the region is less than or equal to 6.2% of the second principal surface of the substrate.
An optical recording medium comprising:
- a substrate having a first principal surface and a second principal surface;
- a first information signal layer on the first principal surface of the substrate configured to record or reproduce information signals upon irradiation with light;
- and
- a barrier layer on the second principal surface of the substrate that suppresses the release of gas from the second principal surface of the substrate,
- wherein the barrier layer is an intermediary circular ring structured to expose a region of the second principal surface of the substrate composed of an inner circular ring and an outer circular ring, and
- wherein an area of the region is a sum of an area of the inner circular ring plus an area of the outer circular ring that is less than or equal to 6.2% of the second principal surface of the substrate.
Dependencies are inferred from the claim text.