US3787888A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recording apparatus with beam intensity control means
Assignee: Honeywell Inc
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Filing: 1971-10-15
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Granted: 1974-01-22
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Expires: 1991-10-15
Abstract
Abstract Focusing means in the path of a beam of coherent electromagnetic waves focus the beam on a focal plane. The beam intensity varies across its diameter. First transparent refractive means in the path of the more intense portion of the beam transmits the waveforms but retards their phase. Second transparent refractive means in the path of the less intense portion of the beam transmits the less intense waveforms but retards their phase an amount different from that of the first refractive means. Interference at the focal plane between the phase changed waveforms alters the original intensity profile of the waveforms. By controlling the relative phase changes the intensity pattern can be altered to be substantially uniform across the beam with only small loss of energy.
Inventors
- 👤 H Haskal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 00:37
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/03; G02F1/0327; G02F1/0121
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
255 words
A system for storing electrical signals, comprising a recording medium, means for producing a beam of coherent electromagnetic waves whose intensity varies radially outward from the center of the beam, modulating means cooperating with said beam producing means for modulating the beam, control means in the path of the beam for focusing the beam on said recording medium and for moving the beam upon various sections of said recording medium, first transparent refractive means in the path of the more intense portion of the beam for transmitting the waveforms in the more intense portion and having a first index of refraction for phase retardation of the coherent waves, second transparent refractive means in the path of the less intense portion of the beam for transmitting the waves in the less intense portion of the beam and having an index of refraction different than said first index for changing their phase an amount different from that of said first refractive means, said phase change caused by said first and second transparent refractive means being effective to cause interference at said recording medium so as to alter the intensity pattern of the waveforms according to a predetermined pattern, one of said refractive means comprising a material having a variable refractive index variable in response to an external stimulus, and external means for applying said stimulus to said refractive means to change said refractive index and hence the phase change of said refractive means for controlling the intensity pattern at said medium to achieve a given intensity pattern.
Claim 2
Independent Claim
255 words
A system for storing electrical signals, comprising a recording medium, means for producing a beam of coherent electromagnetic waves whose intensity varies radially outward from the center of the beam, modulating means cooperating with said beam producing means for modulating the beam, control means in the path of the beam for focusing the beam on said recording medium and for moving the beam upon various sections of said recording medium, first transparent refractive means in the path of the more intense portion of the beam for transmitting the waveforms in the more intense portion and having a first index of refraction for phase retardation of the coherent waves, second transparent refractive means in the path of the less intense portion of the beam for transmitting the waves in the less intense portion of the beam and having an index of refraction different than said first index for changing their phase an amount different from that of said first refractive means, said phase change caused by said first and second transparent refractive means being effective to cause interference at said recording medium so as to alter the intensity pattern of the waveforms according to a predetermined pattern, one of said refractive means comprising a material having a variable refractive index variable in response to an external stimulus, and external means for applying said stimulus to said refractive means to change said refractive index and hence the phase change of said refractive means for controlling the intensity pattern at said medium to achieve a given intensity pattern.
Claim 3
Dependent Claim
47 words
A system as in claim 1 wherein each of said refractive means transmit substantially all the energy in the waveforms passing through the respective refractive means and any energy absorbed by said refractive means is absorbed in virtually the same proportion in both of said refractive means.
Claim 4
Dependent Claim
41 words
Apparatus as in claim 1, wherein the means for producing a beam of coherent electromagnetic waves is a laser and wherein said refractive means each includes a transparent material, said materials having different refractive indices with respect to the laser beam.
Claim 5
Independent Claim
270 words
A system for storing electrical signals comprising a recording medium, laser means for producing a beam of coherent electromagnetic waves whose intensity varies radially outwardly from the center of the beam, modulating means cooperating with said laser means for modulating the beam, control means in the path of the beam for focusing the beam on said recording medium and for moving the beam upon various sections of said recording medium, first refractive means comprised of a transparent material located in the path of the more intense portion of the beam for transmitting the waveforms in the more intense portion and having a first index of refraction for phase retardation of the coherent waves, second refractive means comprised of a transparent material in the path of the less intense portion of the beam for transmitting the waves in the less intense portion of the beam and having an index of refraction different than the first index for changing their phase an amount different from that of said first refractive means, one of said transparent materials comprising an electro-optic material whose refractive index varies according to the strength of an electric field, and electrode means for forming an electric field in said electro-optic material whereby the refractive index and hence the phase change of said refractive means comprising said electro-optical material is controlled in accordance with said electric field, said phase change caused by said first and second refractive means being effective to cause interference at said recording medium so as to alter the iNtensity pattern being variable to achieve a given pattern by varying the strength of the said electric field.
Claim 6
Independent Claim
270 words
A system for storing electrical signals comprising a recording medium, laser means for producing a beam of coherent electromagnetic waves whose intensity varies radially outwardly from the center of the beam, modulating means cooperating with said laser means for modulating the beam, control means in the path of the beam for focusing the beam on said recording medium and for moving the beam upon various sections of said recording medium, first refractive means comprised of a transparent material located in the path of the more intense portion of the beam for transmitting the waveforms in the more intense portion and having a first index of refraction for phase retardation of the coherent waves, second refractive means comprised of a transparent material in the path of the less intense portion of the beam for transmitting the waves in the less intense portion of the beam and having an index of refraction different than the first index for changing their phase an amount different from that of said first refractive means, one of said transparent materials comprising an electro-optic material whose refractive index varies according to the strength of an electric field, and electrode means for forming an electric field in said electro-optic material whereby the refractive index and hence the phase change of said refractive means comprising said electro-optical material is controlled in accordance with said electric field, said phase change caused by said first and second refractive means being effective to cause interference at said recording medium so as to alter the iNtensity pattern being variable to achieve a given pattern by varying the strength of the said electric field.
Claim 7
Dependent Claim
77 words
A system as in claim 4, wherein the intensity of the beam formed by said source means follows a predetermined Gaussian pattern and wherein one of said materials is aligned with the center of the beam and the other of said materials surrounds the first of said crystals, the first of said materials being electro-optic, said electrode means including an electrode at the interface between said materials, and control means for controlling the voltage of said electrode.
Claim 8
Dependent Claim
83 words
Apparatus as in claim 5 further comprising compensating means in the path of said beam, said compensating means having a center refractive portion and a surrounding refractive portion, said refractive portions having respective indices of refraction to reverse the phase changes imparted by said first refractive means and said second refractive means when no voltage exists across said electrodes so that in the unenergized condition of the electrodes said refractive means and said compensating means impart no net phase change to said waveforms.
Claim 9
Dependent Claim
59 words
Apparatus as in claim 6 wherein said control means include sensing means extending in the path of the beam for sensing the relative intensities of two points in the beam, and means connected to said sensing and said electrode means for adjusting of the voltage said electrode means in response to the relative intensities sensed by said sensing means.
References Cited (Backward Citations)
US3328723A
Cited
US3465347A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |