Patent US4199783A successfully refreshed from Google Patents.
US4199783A
Expired / Lapsed
US
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Optical system for recording and reading an information on a tape
Assignee: Thales SA
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Filing: 1978-04-25
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Granted: 1980-04-22
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Expires: 1998-04-25
Abstract
Abstract An optical system for recording n information signals on a photosensitive tape in the form of a discontinuous track made up of parallel track sections by means of n light beams having a two states modulated intensity, being simultaneously deflected by an acousto-optical deflector and focusing on the tape in the form of n equidistant spots aligned in a direction x. The combination of the deflection and a translation movement of the tape produces a scanning movement of said n spots in a direction perpendicular to x. The same system is made for the reading of the information transcribed on the tape, the beams being then not modulated, by means of photodetector means which receive the light emerging from the tape and provide information signals in relation with the physical modifications obtained on the tape during the recording.
Inventors
- 👤 Jean P. Huignard
- 👤 Jean-Claude Lehureau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:17
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B7/125; G11B7/128; G11B7/002; G11B7/003
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
200 words
An optical recording and reading system for recording information signals on a light-sensitive tape and for subsequently reading the recorded information, said system comprising light emissive means for providing n beams of coherent light, projection means for focusing said beams on said tape into n equidistant spots aligned in a direction x, acousto-optical deflection means interposed between said emissive means and said projection means, producing a simultaneous recurrent displacement of said n spots in a direction perpendicular to x, a transport mechanism providing a translation movement of said tape in a direction u; the combination of said recurrent displacement and said translation movement giving a first scanning movement of said n spots relative to said tape along a succession of parallel track sections; said system further comprising modulator means intended for the recording of n information signals providing a two states intensity modulation of said n beams respectively in respect of said n information signals; said intensity modulation producing optically detectable modifications of a physical characteristic of said tape; said system further comprising photodetector means intended for the reading of said physical modifications, receiving the light emerging from said tape and providing n information signals in respect with said modifications.
Claim 2
Dependent Claim
200 words
An optical recording and reading system for recording information signals on a light-sensitive tape and for subsequently reading the recorded information, said system comprising light emissive means for providing n beams of coherent light, projection means for focusing said beams on said tape into n equidistant spots aligned in a direction x, acousto-optical deflection means interposed between said emissive means and said projection means, producing a simultaneous recurrent displacement of said n spots in a direction perpendicular to x, a transport mechanism providing a translation movement of said tape in a direction u; the combination of said recurrent displacement and said translation movement giving a first scanning movement of said n spots relative to said tape along a succession of parallel track sections; said system further comprising modulator means intended for the recording of n information signals providing a two states intensity modulation of said n beams respectively in respect of said n information signals; said intensity modulation producing optically detectable modifications of a physical characteristic of said tape; said system further comprising photodetector means intended for the reading of said physical modifications, receiving the light emerging from said tape and providing n information signals in respect with said modifications.
Claim 3
Dependent Claim
28 words
A system as claimed in claim 1, wherein said emissive means comprise an array of n aligned equidistant laser sources respectively emitting n divergent beams having parallel axis.
Claim 4
Dependent Claim
54 words
A system as claimed in claim 2, wherein said acousto-optical deflection means comprise an acousto-optical deflector of which the acoustic wave planes are parallel to the direction of alignment of said n sources and excitation means producing a sawtooth variation of the angle of deflection of said deflector at a constant scanning frequency f.
Claim 5
Dependent Claim
51 words
A system as claimed in claim 3, wherein said emissive means further comprise a cylindrical lens and a spherical lens converting respectively said n divergent beams into n flattened and parallel beams having an angle of incidence relative to the acoustic wave planes of said deflector equal to the Bragg angle.
Claim 6
Dependent Claim
58 words
A system as claimed in claim 4, wherein said projection means comprise a spherical lens, a cylindrical lens and an objective lens converting respectively the n beams emerging from said acousto-optical deflector into n convergent beams focusing on said tape, the rate between the inter-distance of said n spots and the inter-distance of said n sources being predetermined.
Claim 7
Dependent Claim
49 words
A system as claimed in claim 2 for recording and reading a television signal, said system further comprising electronic means for converting said television signal into n synchronous digital signals, said scanning frequency f being equal to k times the line-frequency of said television signal, k being an integer.
Claim 8
Dependent Claim
52 words
A system as claimed in claim 6, further comprising mechanical deflecting means interposed between said projecting means and said tape providing a second scanning movement of said n spots in a direction different from that of said first scanning movement and with a frequency equal to the frame-frequency of said television signal.
Claim 9
Dependent Claim
16 words
A system as claimed in claim 7, wherein said mechanical deflecting means comprise a pivoting mirror.
Claim 10
Dependent Claim
17 words
A system as claimed in claim 1, wherein said direction x is parallel to said direction u.
Claim 11
Dependent Claim
24 words
A system as claimed in claim 9, wherein the interdistance of said n spots is equal to the distance between two consecutive track sections.
Claim 12
Dependent Claim
24 words
A system as claimed in claim 9, wherein the interdistance of said n spots is greater than the distance between 2 consecutive track sections.
Claim 13
Dependent Claim
41 words
A system as claimed in claim 1, wherein said direction x makes an angle θ other than 0 with said direction u, the track sections respectively followed by said n spots forming n sets belonging to adjacent ranges of said tape.
Claim 14
Dependent Claim
40 words
A system as claimed in claim 1, further comprising mechanical deflecting means interposed between said projecting means and said tape providing a second scanning movement of said n spots in a direction different from that of said first scanning movement.
Claim 15
Dependent Claim
16 words
A system as claimed in claim 13, wherein said mechanical deflecting means comprise a pivoting mirror.
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) | 1983-04-22 | 1983-10-22 | 1984-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-22 | 1987-10-22 | 1988-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-22 | 1991-10-22 | 1992-04-22 | $7700.00 | Window Closed / Lapsed |