US3882214A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Trapezoidal smooth grooves for video disc
Assignee: RCA Corp
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Filing: 1973-02-09
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Granted: 1975-05-06
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Expires: 1993-02-09
Abstract
Abstract A method of forming a disc having an information recording groove of regular cross-sectional shape by forming a preliminary spiral groove of trapezoidal cross-section in a disc having a relatively flat surface, and then flowing an excess of viscous material on the groove surface of the disc while rotating the disc rapidly and long enough to flow off the excess viscous material so as to leave a continuous coating of viscous material over the surface of the disc, the trapezoidal regions being covered by a coating having a relatively constant radius of curvature.
Inventors
- 👤 Richard William Nosker
- 👤 Leonard Pincus Fox
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:19
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/12; G11B3/00; G11B3/68; G11B3/70; G11B3/72; G11B9/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
111 words
A method of forming a grooved disc for recording information therein comprising: forming a spiral groove to a trapezoidal cross-sectional shape in a disc having a relatively flat surface; filling said groove with viscous fluid material; and rotating said disc at a speed commensurate with viscosity of said fluid material to drive off a portion of said fluid material from said disc, leaving a residue of said fluid material coating the groove region of said disc and causing said fluid material to assume, when solidified, a regularly curved cross-sectional shape including inflection points on each wall of said groove located closer to the peaks than to the valley of said groove.
Claim 2
Independent Claim
111 words
A method of forming a grooved disc for recording information therein comprising: forming a spiral groove to a trapezoidal cross-sectional shape in a disc having a relatively flat surface; filling said groove with viscous fluid material; and rotating said disc at a speed commensurate with viscosity of said fluid material to drive off a portion of said fluid material from said disc, leaving a residue of said fluid material coating the groove region of said disc and causing said fluid material to assume, when solidified, a regularly curved cross-sectional shape including inflection points on each wall of said groove located closer to the peaks than to the valley of said groove.
Claim 3
Dependent Claim
39 words
A method of forming a grooved disc for recording information therein according to claim 1, wherein: said fluid material is an energy sensitive material having a viscosity selected with respect to said speed to form said regularly curved shape.
Claim 4
Independent Claim
143 words
A method of forming a grooved disc for recording information therein comprising: forming a spiral groove of triangular cross-sectional shape in a disc having a relatively flat surface such that adjacent convolutions of said triangular groove are separated by a flat region of predetermined width; replicating said disc to form a grooved disc having a groove of trapezoidal cross-section; filling said trapezoidal groove with viscous fluid material; and rotating said disc at a speed commensurate with the viscosity of said fluid material to drive off a portion of said fluid material from said disc leaving a continuous coating of said material over the groove region of said disc and causing said fluid material to assume, when solidified, a regularly curved cross-sectional shape including inflection points on each wall of said groove located closer to the peaks than to the valley of said groove.
Claim 5
Independent Claim
143 words
A method of forming a grooved disc for recording information therein comprising: forming a spiral groove of triangular cross-sectional shape in a disc having a relatively flat surface such that adjacent convolutions of said triangular groove are separated by a flat region of predetermined width; replicating said disc to form a grooved disc having a groove of trapezoidal cross-section; filling said trapezoidal groove with viscous fluid material; and rotating said disc at a speed commensurate with the viscosity of said fluid material to drive off a portion of said fluid material from said disc leaving a continuous coating of said material over the groove region of said disc and causing said fluid material to assume, when solidified, a regularly curved cross-sectional shape including inflection points on each wall of said groove located closer to the peaks than to the valley of said groove.
Claim 6
Dependent Claim
39 words
A method of forming a grooved disc for recording information therein according to claim 3, wherein: said fluid material comprises an energy sensitive material having a viscosity selected with respect to said speed to form said regularly curved shape.
Claim 7
Independent Claim
138 words
A method of forming a grooved disc for recording information therein comprising: forming a groove to a trapezoidal cross-sectional shape in a substrate having a relatively flat surface; replicating said grooved substrate to form a positive replica having a groove of trapezoidal cross-section; filling said last-named groove with viscous fluid material; and rotating said replica at a speed commensurate with viscosity of said fluid material to drive off a portion of said fluid material from said disc leaving a continuous coating of said material over the groove region of said disc and causing said fluid material to assume, when solidified, a curved cross-sectional shape of substantially constant radius of curvature below inflection points located on each wall of said coated groove, said points of inflection located closer to the peaks than to the valley of said coated groove.
Claim 8
Independent Claim
138 words
A method of forming a grooved disc for recording information therein comprising: forming a groove to a trapezoidal cross-sectional shape in a substrate having a relatively flat surface; replicating said grooved substrate to form a positive replica having a groove of trapezoidal cross-section; filling said last-named groove with viscous fluid material; and rotating said replica at a speed commensurate with viscosity of said fluid material to drive off a portion of said fluid material from said disc leaving a continuous coating of said material over the groove region of said disc and causing said fluid material to assume, when solidified, a curved cross-sectional shape of substantially constant radius of curvature below inflection points located on each wall of said coated groove, said points of inflection located closer to the peaks than to the valley of said coated groove.
Claim 9
Dependent Claim
24 words
A method of forming a grooved disc for recording information therein according to claim 5, wherein: said fluid material is an energy sensitive material.
References Cited (Backward Citations)
US3010153A
Cited
US3795534A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |