Patent US4974581A successfully refreshed from Google Patents.
Patent US3812496A successfully refreshed from Google Patents.
US3812496A
Expired / Lapsed
US
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Optical signal recording system
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1972-08-22
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Granted: 1974-05-21
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Expires: 1992-08-22
Abstract
Abstract An optical system for recording time-varying signals which may have a wide range of amplitudes. The signal is recorded on a light sensitive material by means of an unmodulated and a modulated coherent light beam. The two light beams generate a diffraction grating on the recording material. Since one of the beams is modulated the grating is modulated. The recording is preferably effected through a slit having a narrow dimension in the direction of motion of the film and a relatively long direction normal thereto. The modulation may be effected, for example, by modulating the intensity of one of the beams, the phase of the recording beams or the angle between the two beams. The instantaneous signal value is represented by the contrast, spatial frequency or the phase of the grating pattern. The signal may be reproduced by a reproducing beam. The light beam is diffracted in accordance with the grating constant of the diffraction grating and may be picked up by a photosensitive detector. It is also feasible to read out simultaneously a large portion of the recorded track to obtain the Fourier transform of the signal or its power spectrum.
Inventors
- 👤 R Brooks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:49
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/002; G11B7/003; G01; G01D; G01D15/00; G01D15/14; G11B7/004; G11B7/0065
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
205 words
An optical system for recording a plurality of time-varying analog electrical signals, said system comprising: a. a laser for generating coherent light; b. means for splitting the laser light into a first beam, a second beam and a third beam; c. optical means for recombining said beams in a predetermined plane; d. a recording material disposed in said plane; e. means coupled to said recording material and to said optical means for creating a continuous relative movement between said recording material and said beams; f. means for modulating said first beam in accordance with a first analog electric signal to be recorded, whereby a first grating is recorded on said recording material, said first grating being modulated in accordance with said first signal; and g. means for modulating said second beam in accordance with a second analog electrical signal to be recorded, whereby a second grating is recorded on said recording material, said second grating being superimposed on said first grating and being modulated in accordance with said second signal, said first and third beams forming a first predetermined angle at said plane, and said second and third beam forming a second, different predetermined angle at said plane whereby said gratings have different grating constants.
Claim 2
Dependent Claim
205 words
An optical system for recording a plurality of time-varying analog electrical signals, said system comprising: a. a laser for generating coherent light; b. means for splitting the laser light into a first beam, a second beam and a third beam; c. optical means for recombining said beams in a predetermined plane; d. a recording material disposed in said plane; e. means coupled to said recording material and to said optical means for creating a continuous relative movement between said recording material and said beams; f. means for modulating said first beam in accordance with a first analog electric signal to be recorded, whereby a first grating is recorded on said recording material, said first grating being modulated in accordance with said first signal; and g. means for modulating said second beam in accordance with a second analog electrical signal to be recorded, whereby a second grating is recorded on said recording material, said second grating being superimposed on said first grating and being modulated in accordance with said second signal, said first and third beams forming a first predetermined angle at said plane, and said second and third beam forming a second, different predetermined angle at said plane whereby said gratings have different grating constants.
Claim 3
Dependent Claim
251 words
An optical system for recording a plurality of time-varying analog electrical signals, said system comprising: a. a laser for generating coherent light; b. means for splitting the laser light into a first beam, a second beam and a third beam; c. optical means for recombining said beams in a predetermined plane; d. a recording material disposed in said plane; e. means coupled to said recording material and to said optical means for creating a continuous relative movement between said recording material and said beams; f. means for modulating said first beam in accordance with a first analog electric signal to be recorded, whereby a first grating is recorded on said recording material, said first grating being modulated in accordance with said first signal; g. means for modulating said second beam in accordance with a second analog electrical signal to be recorded, whereby a second grating is recorded on said recording material, said second grating being superimposed on said first grating and being modulated in accordance with said second signal, said first and third beams forming a first predetermined angle at said plane, and said second and third beam forming a second, different predetermined angle at said plane whereby said gratings have different grating constants; and h. optical means disposed in the paths of said beams for forming said beams into a substantially rectangular shape at said plane, said rectangle having a relatively small dimension in the direction of relative movement of the recording material and a relatively large dimension normal thereto.
Claim 4
Dependent Claim
251 words
An optical system for recording a plurality of time-varying analog electrical signals, said system comprising: a. a laser for generating coherent light; b. means for splitting the laser light into a first beam, a second beam and a third beam; c. optical means for recombining said beams in a predetermined plane; d. a recording material disposed in said plane; e. means coupled to said recording material and to said optical means for creating a continuous relative movement between said recording material and said beams; f. means for modulating said first beam in accordance with a first analog electric signal to be recorded, whereby a first grating is recorded on said recording material, said first grating being modulated in accordance with said first signal; g. means for modulating said second beam in accordance with a second analog electrical signal to be recorded, whereby a second grating is recorded on said recording material, said second grating being superimposed on said first grating and being modulated in accordance with said second signal, said first and third beams forming a first predetermined angle at said plane, and said second and third beam forming a second, different predetermined angle at said plane whereby said gratings have different grating constants; and h. optical means disposed in the paths of said beams for forming said beams into a substantially rectangular shape at said plane, said rectangle having a relatively small dimension in the direction of relative movement of the recording material and a relatively large dimension normal thereto.
Claim 5
Dependent Claim
189 words
An optical system for recording a time-varying analog electrical signal having a wide range of amplitudes, said system comprising: a. a laser for generating a coherent light beam; b. means for splitting the laser light into a first, a second, a third and a fourth beam; c. optical means for recombining said first and said second beam in a predetermined plane and for recombining said third and fourth beam in said predetermined plane and adjacent said first and second beams; d. a recording material disposed in said plane; e. means coupled to said recording material and to said optical means for creating a continuous relative movement between said recording material on the one hand and said first and second beam, and said third and fourth beam on the other hand; and f. means for modulating said first beam in accordance with an electrical analog signal to be recorded, whereby a first modulated grating is recorded on said recording material, and whereby a second unmodulated grating is recorded on said recording material, so that the signal may be recovered as the ratio of the diffraction efficiencies of said two gratings.
Claim 6
Dependent Claim
189 words
An optical system for recording a time-varying analog electrical signal having a wide range of amplitudes, said system comprising: a. a laser for generating a coherent light beam; b. means for splitting the laser light into a first, a second, a third and a fourth beam; c. optical means for recombining said first and said second beam in a predetermined plane and for recombining said third and fourth beam in said predetermined plane and adjacent said first and second beams; d. a recording material disposed in said plane; e. means coupled to said recording material and to said optical means for creating a continuous relative movement between said recording material on the one hand and said first and second beam, and said third and fourth beam on the other hand; and f. means for modulating said first beam in accordance with an electrical analog signal to be recorded, whereby a first modulated grating is recorded on said recording material, and whereby a second unmodulated grating is recorded on said recording material, so that the signal may be recovered as the ratio of the diffraction efficiencies of said two gratings.
Claim 7
Dependent Claim
236 words
An optical system for recording a time-varying analog electrical signal having a wide range of amplitudes, said system comprising: a. a laser for generating a coherent light beam; b. means for splitting the laser light into a first, a second, a third and a fourth beam; c. optical means for recombining said first and said second beam in a predetermined plane and for recombining said third and fourth beam in said predetermined plane and adjacent said first and second beams; d. a recording material disposed in said plane; e. means coupled to said recording material and to said optical means for creating a continuous relative movement between said recording material on the one hand and said first and second beam, and said third and fourth beam on the other hand; f. means for modulating said first beam in accordance with an electrical analog signal to be recorded, whereby a first modulated grating is recorded on said recording material, and whereby a second unmodulated grating is recorded on said recording material, so that the signal may be recovered as the ratio of the diffraction efficiencies of said two gratings; and g. a mask having an aperture disposed in front of said predetermined plane and in the path of said beams, said aperture having a slit with a relatively small opening in the direction of relative movement of the recording material and a relatively large opening normal thereto.
Claim 8
Dependent Claim
236 words
An optical system for recording a time-varying analog electrical signal having a wide range of amplitudes, said system comprising: a. a laser for generating a coherent light beam; b. means for splitting the laser light into a first, a second, a third and a fourth beam; c. optical means for recombining said first and said second beam in a predetermined plane and for recombining said third and fourth beam in said predetermined plane and adjacent said first and second beams; d. a recording material disposed in said plane; e. means coupled to said recording material and to said optical means for creating a continuous relative movement between said recording material on the one hand and said first and second beam, and said third and fourth beam on the other hand; f. means for modulating said first beam in accordance with an electrical analog signal to be recorded, whereby a first modulated grating is recorded on said recording material, and whereby a second unmodulated grating is recorded on said recording material, so that the signal may be recovered as the ratio of the diffraction efficiencies of said two gratings; and g. a mask having an aperture disposed in front of said predetermined plane and in the path of said beams, said aperture having a slit with a relatively small opening in the direction of relative movement of the recording material and a relatively large opening normal thereto.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-20 | 1977-11-19 | 1978-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-20 | 1981-11-19 | 1982-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-20 | 1985-11-19 | 1986-05-21 | $7700.00 | Window Closed / Lapsed |