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EP0569664A1 Expired / Lapsed EP ⏱️ 0.0 years remaining

Optical information recording medium and recording method using said recording medium

Assignee: Ricoh Co Ltd
•
Filing: 1993-02-05
•
Granted: —
•
Expires: 2013-02-05
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Abstract

Abstract An optical information recording medium capable of recording information, reproducing recorded information, erasing recorded information, and rewriting recorded information, is composed of a substrate, a recording layer formed on the substrate, the recording layer including as the main component a four-component phase-change recording material comprising Ag, In, Te and Sb, and containing a crystalline phase composed of the microcrystallites of AgSbTe₂ at the erasure of recorded information, an upper heat resistant protective layer formed on the recording layer, the upper heat resistant protective layer including a heat resistant material with a thermal conductivity of 1.0 W/cm·deg or more, and an optical reflecting layer formed on the upper heat resistant protective layer. Optical information can be recorded in this recording medium by applying a laser beam to the recording layer through the substrate at a linear velocity of disc rotation of 1.2 to 5.6 m/sec.

Inventors

  • 👤 Yukio Ide
  • 👤 Makoto Harigaya
  • 👤 Yoshiyuki Kageyama
  • 👤 Hiroko Iwasaki

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-09 14:07
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/252; G11B7/257; B; B82; B82Y; B82Y30/00; G11B7/004; G11B7/0055; G11B7/00557; G11B7/242; G11B7/243; G11B7/258; G11B2007/24302; G11B2007/24308; G11B2007/2431; G11B2007/24314; G11B2007/24316; G11B2007/25705; G11B2007/25708; G11B2007/2571; G11B2007/25711; G11B2007/25713; G11B7/259; G11B7/2595

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 108 words
An optical information recording medium capable of recording information, reproducing recorded information, erasing recorded information, and rewriting recorded information, comprising: a substrate, a recording layer formed on said substrate, said recording layer comprising as the main component a four-component phase-change recording material comprising Ag, In, Te and Sb, and containing a microcrystalline phase comprising the crystallites of AgSbTe₂ at the erasure of recorded information, an upper heat resistant protective layer formed on said recording layer, said upper heat resistant protective layer comprising a heat resistant material with a thermal conductivity of 1.0 W/cm·deg or more, and an optical reflecting layer formed on said upper heat resistant protective layer.
Claim 2
Dependent Claim 28 words
The optical information recording medium as claimed in Claim 1, wherein said crystallites of AgSbTe₂ in said microcrystalline phase is in the range of 1000 Å or less.
Claim 3
Dependent Claim 69 words
The optical information recording medium as claimed in Claim 1 or 2, wherein said heat resistant material for said upper heat resistant protective layer is selected from cubic-BN, SiC, and AlN, and said phase-change recording material contained as the main component in said recording layer at erasure is represented by formula: (AgSbTe₂) x (InSb y ) 1-x wherein 0.4 ≦ x ≦ 0.55 and 0.5 ≦ y ≦ 2.5.
Claim 4
Dependent Claim 31 words
The optical information recording medium as claimed in any one of Claims 1-3, further comprising a lower heat resistant protective layer which is interposed between said substrate and said recording layer.
Claim 5
Dependent Claim 28 words
The optical information recording medium as claimed in any one of Claims 1-4, wherein said optical reflecting layer comprises a component selected from Ag, Au or alloys thereof.
Claim 6
Dependent Claim 69 words
An optical information recording method using an optical information recording medium according to any one of Claims 1-5, which method comprises the step of applying a laser beam to said recording layer through said substrate as the optical information recording medium is rotated at a linear velocity of 1.2 to 5.6 m/sec corresponding to CD linear velocity of disc rotation to 4 times CD linear velocity of disc rotation.

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