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US3798388A Expired / Lapsed US ⏱️ 0.0 years remaining

Record carrier for storing angularly modulated signals

Assignee: Licentia Patent Verwaltungs GmbH
•
Filing: 1971-09-13
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Granted: 1974-03-19
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Expires: 1991-09-13
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Abstract

Abstract A method and apparatus for reproducing signals stored on a carrier in the form of undulations corresponding to the signals, the undulations generally being formed in a spiral groove. The undulations on the carrier are moved past a suitable radiation source, such as a light source, and the density of the radiation emanating from the undulations, which is a function of the curvature of the undulation, is detected by a suitable radiation detector after it passes through a suitable slit aperture arranged at a predetermined distance from the carrier surface, so that variations in the density are a function of the undulations. The undulations may be either frequency or phase modulated with respect to the signal and their amplitude can be modified as a function of their recorded wavelength in such a maner that the curved surface portions of the undulations have nearly the same focal length for all occurring wavelengths. The carrier can have at least one recording surface in which is formed a groove having a trapezoidal cross section and having its bottom surface provided with the undulations.

Inventors

  • 👤 G Dickopp

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 07:21
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/004; G11B7/007; G11B7/08; G11B7/085; G11B7/12

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 151 words
An element for storing a reproducible signal in the form of a carrier oscillation which is angularly modulated with the signal to be reproduced, comprising, in combination, signal storage means having at least one recording surface and at least one track arranged in said recording surface, and undulations having continuously curved surfaces formed in said at least one track so as to form a series of quasi-cylinders having axes extending transversely to the direction of the track, the undulations being a representation of a signal modulated with a carrier oscillation, and the successive undulations having lengths, in the direction of the track, which correspond to the periods of successive cycles of the modulated carrier oscillation while the heights of the undulations differ from one undulation to another, the height of each undulation being a direct function of its length such that all of the undulations have substantially the same focal length.
Claim 2
Dependent Claim 151 words
An element for storing a reproducible signal in the form of a carrier oscillation which is angularly modulated with the signal to be reproduced, comprising, in combination, signal storage means having at least one recording surface and at least one track arranged in said recording surface, and undulations having continuously curved surfaces formed in said at least one track so as to form a series of quasi-cylinders having axes extending transversely to the direction of the track, the undulations being a representation of a signal modulated with a carrier oscillation, and the successive undulations having lengths, in the direction of the track, which correspond to the periods of successive cycles of the modulated carrier oscillation while the heights of the undulations differ from one undulation to another, the height of each undulation being a direct function of its length such that all of the undulations have substantially the same focal length.
Claim 3
Dependent Claim 30 words
An element as defined in claim 1 wherein the storage means is to be scanned by radiation impinging on the undulations and the amplitude of each undulatiOn is represented by:
Claim 4
Dependent Claim 31 words
An element as defined in claim 1 wherein the bottom surface of said at least one groove is at an acute angle with respect to said at least one recording surface.
Claim 5
Dependent Claim 19 words
An element as defined in claim 3 wherein the surface portion of each undulation has a substantially circular shape.
Claim 6
Dependent Claim 27 words
An element as defined in claim 4 wherein the radii of the substantially circular surface portion of a series of undulations are substantially equal to each other.
Claim 7
Dependent Claim 19 words
An element as defined in claim 3, wherein the surface portion of each undulation has a substantially parabolic configuration.
Claim 8
Dependent Claim 28 words
An element as defined in claim 6 wherein the lines of intersection of the surface portions of a series of undulations are substantially parts of the same parabola.
Claim 9
Dependent Claim 16 words
An element as defined in claim 7 further comprising a reflective coating applied to the undulations.

References Cited (Backward Citations)

US1956626A Cited
US2092892A Cited
US2654810A Cited
US3287563A Cited
US3403233A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1977-03-18 1977-09-17 1978-03-19 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1981-03-18 1981-09-17 1982-03-19 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1985-03-18 1985-09-17 1986-03-19 $7700.00 Window Closed / Lapsed

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