Optical recording medium
AssigneeInternational Business Machines Corporation
InventorsMichael H. Lee, Aare Onton, Harold Wieder
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Abstract
An optical recording medium comprising adjacent thin layers of two different materials, which, upon marking with an energy beam, form a marked area comprising an alloy or mixture of the two materials. The optical properties of the marked area has contrast sufficiently different from the optical properties of the unmarked area so that the marked area can be reliably sensed. One of the first of the thin layers comprises a metal and the other of the thin layers comprises a metal or a semiconductor. The metals are taken from the group comprising Al, Au, Pb and Sn and the semiconductors are chosen from the group comprising Ge and Si.
Claims6
An optical storage medium having a predetermined surface profile comprising adjacent thin discrete layers of at least two materials which, upon marking with an energy beam, form a marked area having optical properties different from the optical properties of the unmarked areas;
- said at least two materials being selected from a first material consisting of Al and a second material consisting of Ge;
- said medium, after marking with said energy beam, having a surface profile substantially the same as said predetermined surface profile.
An optical storage medium having a predetermined surface profile including a substrate carrying a first and a second discrete layer of different materials which, upon marking with an energy beam, endothermically form a marked area having optical properties different from the optical properties of the unmarked areas, the improvement comprising:
- said first layer consisting of a metal;
- said second layer consisting of a metal or a semiconductor;
- and
- said medium, after marking with said energy beam to form an alloy or mixture, having a surface profile substantially the same as said predetermined surface profile.
Dependencies are inferred from the claim text.