Patent US3764759A successfully refreshed from Google Patents.
US3764759A
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Method and apparatus for scanning recording carriers by means of radiation beams
Assignee: Licentia Patent Verwaltungs GmbH
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Filing: 1970-11-16
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Granted: 1973-10-09
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Expires: 1990-11-16
Abstract
Abstract For playing back signals, such as video signals, which are stored on a transparent disc-shaped carrier having deformations on its surface that correspond to the pattern of the signal amplitudes and that are produced by means of a pressing process similar to that employed for a phonograph record, the deformations are scanned by means of a light beam which strikes the deformations as the carrier moves relative to a light source, and the beam is deflected, according to the deformations, as it travels through the carrier to a photoreceiver and associated half plane aperture. The light used for scanning is formed in a very narrow beam of radiation which is narrower than the wavelength of the highest recorded frequency and this is achieved through the use of a slit aperture in the path of the light beam.
Inventors
- 👤 F Herriger
- 👤 G Dickopp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:11
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/12
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
198 words
Apparatus for reproducing stored signals from a carrier whose surface is provided with spatial deformations corresponding to a carrier oscillation angularly modulated with the stored signal, the deformations serving to deflect a radiation beam impinging thereon, comprising, in combination: source means for producing a radiation beam which is directed toward the region where the deformations of the carrier will be located during signal reproduction; means for moving the carrier relative to said source means so that said radiation beam progressively scans the deformations; means for directing said radiation beam to progressively sweep over a limited portion of the deformations; an associated radiation receiver having a radiation-sensitive surface exposed to only that portion of the scanning radiation beam emanating from the carrier, which is to one side of the axis of the beam as it is directed to the carrier, so that said receiver receives only such beam portion, for producing signals corresponding to the stored signal; and means for limiting the width of the radiation beam at the location of the median plane of the deformations, in the direction of movement of the carrier, to a value which is no greater than one-half of the shortest recorded wavelength.
Claim 2
Dependent Claim
198 words
Apparatus for reproducing stored signals from a carrier whose surface is provided with spatial deformations corresponding to a carrier oscillation angularly modulated with the stored signal, the deformations serving to deflect a radiation beam impinging thereon, comprising, in combination: source means for producing a radiation beam which is directed toward the region where the deformations of the carrier will be located during signal reproduction; means for moving the carrier relative to said source means so that said radiation beam progressively scans the deformations; means for directing said radiation beam to progressively sweep over a limited portion of the deformations; an associated radiation receiver having a radiation-sensitive surface exposed to only that portion of the scanning radiation beam emanating from the carrier, which is to one side of the axis of the beam as it is directed to the carrier, so that said receiver receives only such beam portion, for producing signals corresponding to the stored signal; and means for limiting the width of the radiation beam at the location of the median plane of the deformations, in the direction of movement of the carrier, to a value which is no greater than one-half of the shortest recorded wavelength.
Claim 3
Dependent Claim
32 words
Apparatus as defined in claim 1, further comprising a half-plane aperture disposed for blocking the transmission of a portion of the raDiation beam, which emanates from a deformation, to said radiation receiver.
Claim 4
Dependent Claim
89 words
Apparatus as defined in claim 1, further comprising: a second radiation receiver having a radiation-sensitive surface exposed to only that other portion of the scanning radiation beam emanating from the carrier, which is to the side of the beam axis which is opposite to said one side thereof, so that said second receiver receives only such other beam portion, for producing signals corresponding to the stored signal; and a push-pull circuit connected to combine the outputs of the respective radiation receivers to produce signals corresponding to the stored signal.
Claim 5
Dependent Claim
61 words
Apparatus as defined in claim 1, wherein said directing means and said limiting means are constituted by a slit aperture which is closely positioned adjacent the location of the deformations during signal reproduction and the width of said slit aperture, in the direction of the relative movement of the carrier, is no greater than one-half of the shortest recorded wave length.
Claim 6
Dependent Claim
31 words
Apparatus as defined in claim 4, wherein the deformations are in a spiral groove in the carrier surface, and said slit aperture is resiliently mounted to be guided in said groove.
Claim 7
Dependent Claim
41 words
Apparatus as defined in claim 4, wherein said slit aperture means is constituted by a solid, transparent slit body member, an opaque guide member, and an intermediate layer permanently connecting said body member with adjacent portions of said opaque guide member.
Claim 8
Dependent Claim
41 words
Apparatus as defined in claim 6, wherein said slit body member has a higher index of refraction than said intermediate layer so that total reflection results in the useful area of the radiation along the lateral bounderies of said body member.
Claim 9
Dependent Claim
15 words
Apparatus as defined in claim 7, wherein said slit body member is a glass foil.
Claim 10
Dependent Claim
25 words
Apparatus as defined in claim 7, wherein said glass foil is connected with said guide member by means of an adhesive constituting said intermediate layer.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-08 | 1977-04-09 | 1977-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-08 | 1981-04-09 | 1981-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-08 | 1985-04-09 | 1985-10-09 | $7700.00 | Window Closed / Lapsed |