US4582776A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Information recording disc having light absorbing cellulose nitrate coating
Assignee: Pioneer Corp
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Filing: 1982-09-28
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Granted: 1986-04-15
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Expires: 2002-09-28
Abstract
Abstract An information recording disc comprising a generally circular substrate having a polished major surface, a light-reflective coating formed on the polished major surface of the substrate, and a light-absorptive coating formed on the surface of the light-reflective coating and formed with information tracks each consisting of a succession of spaced pits in the light-absorptive coating, the light-absorptive coating being composed of a mixture of cellulose nitrate and a dye sensitizer exhibiting a noticeable light absorptivity in response to light with a predetermined wavelength, the cellulose nitrate being prepared from a starting cellulose containing at least about 97% of alpha-cellulose. If desired, the light-reflective coating may be dispensed with so that the light-absorptive information recording coating is formed directly on the polished surface of the substrate.
Inventors
- 👤 Fumio Matsui
- 👤 Manabu Sugano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 01:39
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/252; G11B7/258; G11B23/00; G11B23/0057; G11B7/004; G11B7/0045; G11B7/00451; G11B7/242; G11B7/244; G11B7/245; G11B7/246; Y; Y10; Y10S; Y10S430/00; Y10S430/1053; Y10S430/1055; Y10S430/106; Y10S430/112
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
71 words
An information recording disc, comprising: a generally circular substrate, and a light-absorptive coating secured to said substrate, said light-absorptive coating being a mixture of cellulose nitrate having a degree of nitration higher than about 13% and a dye sensitizer, said dye sensitizer present in an amount sufficient for said coating to exhibit a noticeable light absorptivity, said cellulose nitrate being prepared from a starting cellulose containing at least about 97% alpha-cellulose.
Claim 2
Dependent Claim
71 words
An information recording disc, comprising: a generally circular substrate, and a light-absorptive coating secured to said substrate, said light-absorptive coating being a mixture of cellulose nitrate having a degree of nitration higher than about 13% and a dye sensitizer, said dye sensitizer present in an amount sufficient for said coating to exhibit a noticeable light absorptivity, said cellulose nitrate being prepared from a starting cellulose containing at least about 97% alpha-cellulose.
Claim 3
Dependent Claim
82 words
An information recording disc, comprising: a generally circular substrate, a light-reflective coating formed on said substrate, and a light-absorptive coating formed on the surface of the light-reflective coating said light-absorptive coating being a mixture of cellulose nitrate having a degree of nitration higher than about 13%, and a dye sensitizer, said dye sensitizer present in an amount sufficient for said coating to exhibit a noticeable light absorptivity, said cellulose nitrate being prepared from a starting cellulose containing at least about 97% alpha-cellulose.
Claim 4
Dependent Claim
82 words
An information recording disc, comprising: a generally circular substrate, a light-reflective coating formed on said substrate, and a light-absorptive coating formed on the surface of the light-reflective coating said light-absorptive coating being a mixture of cellulose nitrate having a degree of nitration higher than about 13%, and a dye sensitizer, said dye sensitizer present in an amount sufficient for said coating to exhibit a noticeable light absorptivity, said cellulose nitrate being prepared from a starting cellulose containing at least about 97% alpha-cellulose.
Claim 5
Dependent Claim
34 words
An information recording disc as set forth in claim 1 or 2, in which said cellulose nitrate has a number average degree of polymerization within the range of from about 80 to about 95.
Claim 6
Dependent Claim
45 words
An information recording disc as set forth in claim 1 or 2, in which said cellulose nitrate has a degree of nitration higher than about 13 per cent and a number average degree of polymerization within the range of from about 80 to about 95.
Claim 7
Dependent Claim
19 words
An information recording disc as set forth in claim 1 or 2, in which said dye sensitizer is N-ethyl-N-oxyethylaniline
Claim 8
Dependent Claim
31 words
An information recording disc as set forth in claim 1 or 2, in which the ratio in weight between said cellulose nitrate and said dye sensitizer is from 86.5:13.5 to 80:20.
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) | 1989-04-14 | 1989-10-14 | 1990-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-14 | 1993-10-14 | 1994-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-14 | 1997-10-14 | 1998-04-15 | $7700.00 | Window Closed / Lapsed |