Patent US4262875A successfully refreshed from Google Patents.
US4262875A
Expired / Lapsed
US
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Information record stampers
Assignee: RCA Corp
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Filing: 1979-08-17
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Granted: 1981-04-21
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Expires: 1999-08-17
Abstract
Abstract Video disc nickel stampers are coated with a very thin, e.g., 100-250 angstroms, non-grainy layer of chromium which imparts increased scratch resistance to carbon-filled polyvinylchloride resins during compression molding.
Inventors
- 👤 Frederick R. Nyman
- 👤 Thomas E. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:44
CPC Classifications
B; B29; B29C; B29C33/00; B29C33/56; B29K; B29K2027/00; B29K2027/06; B29K2707/00; B29K2707/04; B29K2905/00; B29K2905/08; Y; Y10; Y10S; Y10S425/00; Y10S425/81
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
37 words
A scratch resistant nickel stamper containing audio and video information in the form of a submicron size surface relief pattern on a surface thereof coated with an about 100-220 angstroms thick, vapor deposited, conformal, chromium containing layer.
Claim 2
Dependent Claim
37 words
A scratch resistant nickel stamper containing audio and video information in the form of a submicron size surface relief pattern on a surface thereof coated with an about 100-220 angstroms thick, vapor deposited, conformal, chromium containing layer.
Claim 3
Dependent Claim
41 words
A stamper according to claim 1 wherein the chromium-containing layer is vapor deposited from an alloy of chromium containing about 78 percent by weight of chromium, about 20 percent by weight of iron and about 2 percent by weight of titanium.
Claim 4
Dependent Claim
27 words
A stamper according to claims 1 wherein a layer of chromium oxide about 20 to 50 angstroms thick is present at the surface of the chromium-containing layer.
Claim 5
Dependent Claim
17 words
A stamper according to claim 1 wherein the surface relief pattern is contained in a spiral groove.
Claim 6
Dependent Claim
14 words
A stamper according to claim 2 wherein the chromium-containing layer is applied by sputtering.
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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) | 1984-04-20 | 1984-10-20 | 1985-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-20 | 1988-10-20 | 1989-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-20 | 1992-10-20 | 1993-04-21 | $7700.00 | Window Closed / Lapsed |