Erasable optical data storage medium and method and apparatus for recording data on the medium
AssigneeOptical Data, Inc.
InventorsClyde D. Feyrer, N. Ross Gordon, W. Eugene Skiens
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Abstract
An erasable optical data storage medium including a substrate and a dual layer of a first material and a second material on the substrate. The dual layer is susceptible to expansion and contraction, to writing data thermally, to erasing data thermally and mechanically, and to reading data optically, the first material and the second material, respectively, being bonded together and remaining in the same physical state upon the expansion and relaxation of the dual layer. Methods and apparatus are also disclosed for recording data bits on the medium.
Claims5
A method of writing and erasing data in an optical data storage medium having a first layer of a first elastic material and a second layer of a second material having a glass transition temperature, said method comprising:
- (a) heating said first material to thermally expand said first material within its elastic limit;
- (b) raising said second material above its glass transition temperature and permitting said expanding first material to deform said second layer causing an optically detectable deformation;
- (c) cooling said second material below its glass transition temperature while said first material is in expanded condition;
- (d) causing said second layer to hold said first material in expanded condition;
- and
- (e) heating said second material above its glass transition temperature and allowing the elastic properties of said expanded, cooled first material to pull said second layer flat, erasing said optically detectable deformation.
Dependencies are inferred from the claim text.