Patent US4297312A successfully refreshed from Google Patents.
US4297312A
Expired / Lapsed
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Method for preparing stylus lapping discs
Assignee: RCA Corp
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Filing: 1980-02-04
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Granted: 1981-10-27
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Expires: 2000-02-04
Abstract
Abstract An improved method of reproducing a spiral groove pattern in the surface of a plastic disc wherein the intersections of the surface of a metal article generated during the replication process are filled in to form concave junctions.
Inventors
- 👤 Charles B. Carroll
- 👤 Howard G. Scheible
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:32
CPC Classifications
C; C25; C25D; C25D1/00; C25D1/10; B; B24; B24B; B24B19/00; B24B19/16; B24B19/165; G; G11; G11B; G11B23/00; G11B23/0057; G11B3/00; G11B3/44; G11B3/56; G11B9/00; G11B9/06; G11B9/07; G11B9/075
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
127 words
In a method of replicating a groove pattern in the formation of a lapping disc comprising the steps of: 1. recording the pattern in a photoresist layer, 2. developing the photoresist layer to form a photoresist master, 3. transferring the pattern of the photoresist master to a metal matrix master pattern by coating the photoresist master with a metal to form an electroform, and separating the electroform from the photoresist master to produce the said metal matrix master pattern, and 4. replicating the metal matrix master pattern in the surface of a plastic article; the improvement which comprises the step of forming concave junctions on the metal matrix master by filling in material at the intersections of the walls and base portions of the metal matrix master.
Claim 2
Dependent Claim
127 words
In a method of replicating a groove pattern in the formation of a lapping disc comprising the steps of: 1. recording the pattern in a photoresist layer, 2. developing the photoresist layer to form a photoresist master, 3. transferring the pattern of the photoresist master to a metal matrix master pattern by coating the photoresist master with a metal to form an electroform, and separating the electroform from the photoresist master to produce the said metal matrix master pattern, and 4. replicating the metal matrix master pattern in the surface of a plastic article; the improvement which comprises the step of forming concave junctions on the metal matrix master by filling in material at the intersections of the walls and base portions of the metal matrix master.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein a spin coating technique is employed in filling in the metal article.
Claim 4
Dependent Claim
26 words
The method of claim 2 wherein a solution of cresol formaldehyde novolak resin and 2,4-bis(6-diazo-5,6-dihydro-5-oxo-1-naphthalene-sulfonyloxy)benzophenone in 2-methoxyethyl acetate is utilized in spin coating the metal layer.
Claim 5
Dependent Claim
11 words
The method of claim 1 wherein the groove is trapezoidally shaped.
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) | 1984-10-26 | 1985-04-27 | 1985-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-26 | 1989-04-27 | 1989-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-26 | 1993-04-27 | 1993-10-27 | $7700.00 | Window Closed / Lapsed |