US4379299A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recording structure for direct read after write recording
Assignee: Philips North America LLC
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Filing: 1981-04-06
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Granted: 1983-04-05
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Expires: 2001-04-06
Abstract
Abstract An information recording medium uses a semiconductor film on a plastic substrate for obtaining a direct read after write digital recording with laser recording and writing devices. The writing laser produces an area of generated heat in the semiconductor film which produces a heated region in the underlying plastic substrate. The heated plastic substrate material decomposes or degases yielding gaseous components with a high pressure that will burst the overlying semiconductor layer leaving a pit or hole in the reflective surface.
Inventors
- 👤 Brian J. Fitzpatrick
- 👤 Rameshwar N. Bhargava
- 👤 Alfred E. Milch
- 👤 Pedro Tasaico
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 01:05
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/252; G11B7/253; G11B7/2533; G11B7/2534; G11B7/004; G11B7/0045; G11B7/00452; G11B7/242; G11B7/243; G11B2007/24302; G11B2007/24304; G11B2007/24316; G11B7/00458; Y; Y10; Y10S; Y10S430/00; Y10S430/146
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
81 words
A method of writing information on a recording medium comprising the steps of forming a Group II-IV semiconductor film of CdTe on a plastic substrate, directing a laser beam to the surface of said semiconductor film, locally generating an area of heat at said semiconductor film where said laser beam is applied, generating high pressure gaseous components of said plastic substrate adjacent to said heated areas of said semiconductor film, and causing said gaseous components to burst through said semiconductor film.
Claim 2
Independent Claim
81 words
A method of writing information on a recording medium comprising the steps of forming a Group II-IV semiconductor film of CdTe on a plastic substrate, directing a laser beam to the surface of said semiconductor film, locally generating an area of heat at said semiconductor film where said laser beam is applied, generating high pressure gaseous components of said plastic substrate adjacent to said heated areas of said semiconductor film, and causing said gaseous components to burst through said semiconductor film.
Claim 3
Dependent Claim
19 words
A method according to claim 1 wherein said plastic substrate is one of polymethylmethacrylate and a polycarbonate plastic material.
References Cited (Backward Citations)
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US4158715A
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Cited
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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) | 1986-04-04 | 1986-10-04 | 1987-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-04-04 | 1990-10-04 | 1991-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-04-04 | 1994-10-04 | 1995-04-05 | $7700.00 | Window Closed / Lapsed |