Patent US5401549A successfully refreshed from Google Patents.
US5401549A
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US
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Optical information recording medium
Assignee: Ricoh Co Ltd
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Filing: 1991-09-26
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Granted: 1995-03-28
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Expires: 2011-09-26
Abstract
Abstract An optical information recording medium includes a ROM region in which information has been recorded in the form of pits in a substrate, and from which the recorded information can be reproduced upon application of a laser beam thereto, and a recording region in which information can be recorded in the form of pits from which the recorded information can be reproduced upon application of a laser beam thereto, with the improvement wherein a reflective layer is provided in a ROM region portion of the substrate in the ROM region, and a recording layer is overlaid on both the reflective layer in the ROM region portion and a recording portion of the substrate in the recording region.
Inventors
- 👤 Kenta Watase
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 11:59
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/007; G11B7/0079; G11B13/00; G11B13/04; G11B13/045; G11B7/24; G11B7/26; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10S430/00; Y10S430/146; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
137 words
In an optical information recording medium of an erasable type comprising a ROM region in which information has been recorded in the form of pits in a substrate, and from which the recorded information can be reproduced upon application of a laser beam thereto, and a recording region in which information can be recorded in the form of pits from which the recorded information can be reproduced upon application of a laser beam thereto, the improvement wherein a reflective layer is provided in a ROM region portion of said substrate in said ROM region, and a recording layer is overlaid on both said reflective layer in said ROM region portion and a recording portion of the substrate in said recording region, said recording layer being of a multi-layer type comprising a dielectric layer and a magnetic layer.
Claim 2
Dependent Claim
137 words
In an optical information recording medium of an erasable type comprising a ROM region in which information has been recorded in the form of pits in a substrate, and from which the recorded information can be reproduced upon application of a laser beam thereto, and a recording region in which information can be recorded in the form of pits from which the recorded information can be reproduced upon application of a laser beam thereto, the improvement wherein a reflective layer is provided in a ROM region portion of said substrate in said ROM region, and a recording layer is overlaid on both said reflective layer in said ROM region portion and a recording portion of the substrate in said recording region, said recording layer being of a multi-layer type comprising a dielectric layer and a magnetic layer.
Claim 3
Dependent Claim
23 words
The optical information recording medium as claimed in claim 1, further comprising an additional reflective layer which is overlaid on said recording layer.
Claim 4
Dependent Claim
23 words
The optical information recording medium as claimed in claim 2, further comprising a protective layer which is overlaid on said additional reflective layer.
Claim 5
Dependent Claim
22 words
The optical information recording medium as claimed in claim 1, further comprising a protective layer which is overlaid on said recording layer.
Claim 6
Dependent Claim
16 words
The optical information recording medium as claimed in claim 1, wherein said dielectric layer comprises SiO.
Claim 7
Dependent Claim
26 words
The optical information recording medium as claimed in claim 1, wherein said magnetic layer comprises an alloy selected from the group consisting of TbFe and TbFeCo.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-03-27 | 1998-09-26 | 1999-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-03-27 | 2002-09-26 | 2003-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-03-27 | 2006-09-26 | 2007-03-28 | $7700.00 | Window Closed / Lapsed |