Sheryl Lynd Johnson

US Patent:

51446138, Sep 1, 1992

Filed:

Jul 26, 1990

Appl. No.:

7/558892

Inventors:

Sheryl L. Johnson - Sunnyvale CA
Bryan K. Clark - Sunnyvale CA

Assignee:

Tandy Corporation - Fort Worth TX

International Classification:

G11B 700
G11B 730

US Classification:

369100

Abstract:

A method of achieving a bulk erasure of a dye polymer optical storage media which includes a substrate, an expansion layer, and a retention layer. The optical storage media is placed into a temperature controlled environment in which the temperature is increased at a first prescribed rate to a prescribed temperature exceeding the glass transition temperature of the retention layer of the media. Above the glass transition temperature, the retention layer is transformed from a glass-like state to a viscoelastic state. While in the viscoelastic state, the retention layer shape conforms to the expansion layer to achieve the unrecorded media configuration (i. e. flat). The temperature of the controlled environment is maintained at the prescribed temperature for a specified period of time to achieve the bulk erasure, then reduced at a second prescribed rate. By controlling the prescribed temperature and specified time period, the media is erased in bulk providing an unrecorded media ready for use. The prescribed temperature, specified time period and temperature change rates are selected to avoid thermal shock and polymer degradation and thus enable many record/erase transitions of the media.

US Patent:

50900080, Feb 18, 1992

Filed:

Apr 30, 1990

Appl. No.:

7/516509

Inventors:

Bryan K. Clark - Sunnyvale CA
Sheryl L. Johnson - Sunnyvale CA
Robert Guerra - Santa Clara CA

Assignee:

Tandy Corporation - Ft. Worth TX

International Classification:

G11B 724
G11B 700
G01D 1534

US Classification:

369284

Abstract:

An optical storage medium is disclosed. In a preferred embodiment a substrate is provided with an expansion layer. A retention layer is provided opposite the substrate. A liquid reflective layer is provided adjacent the retention layer, either adjacent to or opposite the expansion layer. The reflective layer is enclosed by a protective layer. Improved expansion and retention layers are also disclosed.