US4912696A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Erasable optical data storage medium and method and apparatus for recording data on the medium
Assignee: Optical Data Inc
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Filing: 1988-12-20
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Granted: 1990-03-27
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Expires: 2008-12-20
Abstract
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.
Inventors
- 👤 Clyde D. Feyrer
- 👤 N. Ross Gordon
- 👤 W. Eugene Skiens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:16
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/004; G11B7/0045; G11B7/00452; G11B7/0055; G11B7/241; G11B7/242; G11B7/244; G11B7/246; G11B7/248
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
114 words
A method of writing data in an optical data storage medium having a first layer of an elastic first 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 transtion temperature permitting said expanding first material to deform said second layer; (c) cooling said medium so that said second material falls below its glass transition temperature while said first material is in expanded condition; and (d) causing said second layer to hold said first material in expanded condition, storing mechanical energy in said layers.
Claim 2
Independent Claim
114 words
A method of writing data in an optical data storage medium having a first layer of an elastic first 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 transtion temperature permitting said expanding first material to deform said second layer; (c) cooling said medium so that said second material falls below its glass transition temperature while said first material is in expanded condition; and (d) causing said second layer to hold said first material in expanded condition, storing mechanical energy in said layers.
Claim 3
Dependent Claim
40 words
The method of claim 1 including the steps of 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 first, erasing said optically detectable deformation.
Claim 4
Dependent Claim
71 words
The method of claim 2 wherein said second material is cross-linked to reduce viscous flow of said second material when above its glass transition temperature, the expansion of said first material and resultant deformation of said second layer stretching the cross-linking of said second material, the step of heating said second material causing the stretched cross-linking of said seocnd material to relax and assist the erasure of said optically detectable deformation.
Claim 5
Dependent Claim
60 words
the method of claim 2 wherein said second material is adapted to at least partially absorb radiant energy of a second preselected wavelength, the erasure step of said method including generating a second laser beam of said second preselected wavelength and causing it to be absorbed by said second material to heat said second material above its glass transition temperature.
Claim 6
Dependent Claim
45 words
The method of claim 4, inlcuding generating said second laser beam of said second preselected wavelength to heat said second material above its glass transition temperature prior to generating said first laser beam of said first preselected wavelength to heat and expand said first material.
Claim 7
Dependent Claim
29 words
The method of claim 5, including the step of generating said first laser beam of said first preselected wavelength while said second material remains above its glass transition temperature.
Claim 8
Dependent Claim
39 words
The method of claim 4, including the step of dyeing said second material with a dye which is adapted to substantially transmit radiant energy of said first preselected wavelength and substantially absorb radiant energy of said second preselected wavelength.
Claim 9
Independent Claim
128 words
A method of writing data in an optical data storage medium having a first layer of a first material and a second layer of a second material, said method comprising: (a) heating said first material to thermally expand said first material; (b) permitting said expanding first material to deform said second layer causing an optically detectable deformation; (c) cooling said medium; (d) causing said second layer to hold said first material in stretched expanded condition, storing mechanical energy in said layers; and (e) wherein said first material is adpated to substantially absorb radiant energy of a first preselected wavelength, said method including generating a laser beam of said first preselected wavelength and causing it to pass substantially through said second layer and be absorbed by said first material.
Claim 10
Independent Claim
128 words
A method of writing data in an optical data storage medium having a first layer of a first material and a second layer of a second material, said method comprising: (a) heating said first material to thermally expand said first material; (b) permitting said expanding first material to deform said second layer causing an optically detectable deformation; (c) cooling said medium; (d) causing said second layer to hold said first material in stretched expanded condition, storing mechanical energy in said layers; and (e) wherein said first material is adpated to substantially absorb radiant energy of a first preselected wavelength, said method including generating a laser beam of said first preselected wavelength and causing it to pass substantially through said second layer and be absorbed by said first material.
Claim 11
Dependent Claim
23 words
The method of claim 8, including the step of dyeing said first material to substantially absorb radiant energy of said first preselected wavelength.
Claim 12
Dependent Claim
23 words
The method of claim 8, wherein said first and second materials do not liquify, gasify, or undergo change in their crystallographic structure .
Claim 13
Independent Claim
91 words
A method of writing data in an optical data storage medium having a first layer of a first material and a second layer of a second material, said method comprising: (a) heating said first material to thermally expand said first material; (b) permitting said expanding first material to deform said second layer causing an opticallyh detectable deformation; (c) cooling said medium; (d) causing said second layer to hold said first material in stretched expanded condition, storing mechanical energy in said layers; and (e) wherein said first and second materials are amorphous.
Claim 14
Independent Claim
91 words
A method of writing data in an optical data storage medium having a first layer of a first material and a second layer of a second material, said method comprising: (a) heating said first material to thermally expand said first material; (b) permitting said expanding first material to deform said second layer causing an opticallyh detectable deformation; (c) cooling said medium; (d) causing said second layer to hold said first material in stretched expanded condition, storing mechanical energy in said layers; and (e) wherein said first and second materials are amorphous.
Claim 15
Dependent Claim
22 words
The method of claim 11 wherein said first material is elastic, said method including expanding said first material within its elastic limit.
Claim 16
Dependent Claim
16 words
The method of claim 11, including the step of bonding said first and second layers together.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-03-26 | 1993-09-25 | 1994-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-26 | 1997-09-25 | 1998-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-26 | 2001-09-25 | 2002-03-27 | $7700.00 | Window Closed / Lapsed |