US4519064A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical record disc
Assignee: Nippon Columbia Co Ltd
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Filing: 1981-10-22
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Granted: 1985-05-21
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Expires: 2001-10-22
Abstract
Abstract An optical record disc is provided having a guide signal pit previously formed on a base plate for reading out a tracking information by a laser beam. A reflection film is coated on the base plate including the guide signal pit portion, and the record blank portion. A record layer of a removing type is formed over the reflection film. The record layer has a uniform thickness over the record layer and a uniform thickness, of substantially smaller dimension over the guide signal pit portion.
Inventors
- 👤 Toshihiko Takagi
- 👤 Yoshikazu Kobayashi
- 👤 Yoshiji Suzuki
- 👤 Tsutomu Hara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:41
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/09; G11B7/0938; G11B7/24; G11B7/241; G11B7/242; G11B7/244; G11B7/245; G11B7/246; G11B7/247; G11B7/2472; G11B7/252; G11B7/254; G11B7/258; G11B7/2585
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
110 words
An optical record disc, comprising: (a) a base plate having a blank portion of substantially uniform thickness and a guide signal pit portion of projections extending upwardly from one surface of said base plate; (b) a light reflecting film layer on said one surface of said base plate coating, said blank portion and said guide signal pit portion; and (c) a thin layer of recording material of the removing type coated on said reflection film layer, said recording material having a high light absorption factor, a substantially uniform thickness over said blank portion and a thickness over the top sections of said projections substantially smaller than over said blank portion.
Claim 2
Dependent Claim
110 words
An optical record disc, comprising: (a) a base plate having a blank portion of substantially uniform thickness and a guide signal pit portion of projections extending upwardly from one surface of said base plate; (b) a light reflecting film layer on said one surface of said base plate coating, said blank portion and said guide signal pit portion; and (c) a thin layer of recording material of the removing type coated on said reflection film layer, said recording material having a high light absorption factor, a substantially uniform thickness over said blank portion and a thickness over the top sections of said projections substantially smaller than over said blank portion.
Claim 3
Dependent Claim
20 words
An optical record disc as claimed in claim 1, which said record thin layer is made of an organic layer.
Claim 4
Dependent Claim
31 words
An optical record disc as claimed in claim 1, in which said record thin layer is made of an organic layer whose light absorption factor for a record light is increased.
Claim 5
Dependent Claim
24 words
An optical record disc as claimed in claim 3, in which said record thin layer is made of mixture of Nitrocellulose and Nigrosine dye.
Claim 6
Dependent Claim
24 words
An optical record disc as claimed in claim 4, in which a composition ratio of said dye and Nitrocellulose is from 1:2 to 1:10.
Claim 7
Dependent Claim
22 words
An optical record disc as claimed in claim 3, in which said record thin layer is made of Nitrocellulose and Polymethine dye.
Claim 8
Dependent Claim
39 words
An optical record disc as claimed in claim 1, 2, 3, 4, 5 or 6 in which a light passage permissible protective layer is coated on a non-focus surface of said record thin layer at a light incident side.
Claim 9
Dependent Claim
28 words
An optical record disc as claimed in claim 7, in which said protective layer has such a light permissivity which becomes low in a short wave length region.
References Cited (Backward Citations)
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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) | 1988-05-20 | 1988-11-19 | 1989-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-20 | 1992-11-19 | 1993-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-20 | 1996-11-19 | 1997-05-21 | $7700.00 | Window Closed / Lapsed |