US3919700A
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Assignee: International Business Machines Corp
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Filing: 1974-07-22
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Granted: 1975-11-11
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Expires: 1994-07-22
Abstract
Abstract Piezoelectric photosensitive semiconductor crystals or semiinsulators are employed either to store or to process high frequency signals. Storage is accomplished in the crystal by a stable pattern of trapped electrons produced by the interference between two radio-frequency input signal pulses. The latter are applied successively to the crystal, after an initial illumination, causing ultrasonic waves to be generated. The ultrasonic wave of the first pulse, together with the electric field of the second, cause the trapped electrons to be redistributed in a pattern which has the same spatial variation as the ultrasonic wave. In effect, the information contained in the original pulse is stored in the crystal, the latter serving as a recording medium operating over the whole radio frequency range.
Inventors
- 👤 Joseph Cozzo
- 👤 David K Garrod
- 👤 Thomas G Kazyaka
- 👤 Robert L Melcher
- 👤 Norman S Shiren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:03
CPC Classifications
H; H03; H03K; H03K3/00; H03K3/02; H03K3/45; G; G11; G11C; G11C11/00; G11C11/21; G11C11/42; G11C13/00; G11C13/04; G11C13/042
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
117 words
A device for obtaining storage of information comprising a material containing defect sites on which electrons can be trapped and such traps can be subsequently ionized by electric fields, means for applying charging light to said material to fill electron traps therein, means for propagating an r.f. acoustic pulse through said material wherein said acoustic pulse serves as an informationbearing pulse, and means for applying a second r.f. pulse to said material during the presence of said acoustic pulse so as to write said information-bearing pulse as a stable pattern of trapped electrons having the same spatial variations as said acoustic pulse so that the phase and amplitude of said acoustic pulse is retained in the material.
Claim 2
Independent Claim
117 words
A device for obtaining storage of information comprising a material containing defect sites on which electrons can be trapped and such traps can be subsequently ionized by electric fields, means for applying charging light to said material to fill electron traps therein, means for propagating an r.f. acoustic pulse through said material wherein said acoustic pulse serves as an informationbearing pulse, and means for applying a second r.f. pulse to said material during the presence of said acoustic pulse so as to write said information-bearing pulse as a stable pattern of trapped electrons having the same spatial variations as said acoustic pulse so that the phase and amplitude of said acoustic pulse is retained in the material.
Claim 3
Dependent Claim
10 words
The device of claim 1 wherein said material is CdS.
Claim 4
Dependent Claim
20 words
The device of claim 2 wherein said CdS is sulfur doped and has a resistivity > or = 100,000 ohm-cm.
Claim 5
Independent Claim
92 words
A device for storing a holograph acoustically comprising a highly resistive piezoelectric semiconductor, means for providing electron traps in said semiconductor, a phase and amplitude modulated r.f. pulse applied to said semiconductor, the latter converting said pulse to an acoustic wave of the same frequency as said r.f. pulse, and a second r.f. pulse applied to said crystal during the presence of said acoustic wave so as to store said acoustic pulse in the form of a charge distribution of electrons which varies in phase and amplitude as said first r.f. pulse.
Claim 6
Independent Claim
92 words
A device for storing a holograph acoustically comprising a highly resistive piezoelectric semiconductor, means for providing electron traps in said semiconductor, a phase and amplitude modulated r.f. pulse applied to said semiconductor, the latter converting said pulse to an acoustic wave of the same frequency as said r.f. pulse, and a second r.f. pulse applied to said crystal during the presence of said acoustic wave so as to store said acoustic pulse in the form of a charge distribution of electrons which varies in phase and amplitude as said first r.f. pulse.
Claim 7
Dependent Claim
21 words
The device of claim 1 wherein said second r.f. pulse is very much shorter in duration than said first r.f. pulse.
Claim 8
Dependent Claim
35 words
The device of claim 1 including means for applying an r.f. pulse of the same frequency as said first r.f. pulse to said stored charge pattern so as to read out the stored acoustic pulse.
Claim 9
Dependent Claim
37 words
The device of claim 1 including means for applying a second acoustic pulse of the same frequency as said first acoustic pulse to said stored charge pattern so as to read out the stored second r.f. pulse.
Claim 10
Independent Claim
107 words
A device for obtaining the storage of a plurality of information-bearing r.f. signals comprising a fully anion-compensated piezoelectric crystal such as CdS, means for applying charging radiation to said crystal to fill electron traps therein, and means for propagating an r.f. acoustical pulse through said crystal to serve as an information-bearing pulse, and means for applying a plurality of consecutive r.f. pulses, having the same frequency as said acoustic wave, to said crystal during the presence of said acoustic pulse so as to form a plurality of charge distributions of electrons each such distribution varying in phase and amplitude with each of said plurality of r.f. pulses.
Claim 11
Independent Claim
107 words
A device for obtaining the storage of a plurality of information-bearing r.f. signals comprising a fully anion-compensated piezoelectric crystal such as CdS, means for applying charging radiation to said crystal to fill electron traps therein, and means for propagating an r.f. acoustical pulse through said crystal to serve as an information-bearing pulse, and means for applying a plurality of consecutive r.f. pulses, having the same frequency as said acoustic wave, to said crystal during the presence of said acoustic pulse so as to form a plurality of charge distributions of electrons each such distribution varying in phase and amplitude with each of said plurality of r.f. pulses.
Claim 12
Dependent Claim
19 words
The device of claim 1 wherein said r.f. frequencies are in the range of 10 megahertz to 100 gigahertz.
Claim 13
Dependent Claim
126 words
In a memory device for obtaining storage of information comprising a fully anion-compensated piezoelectric crystal having a resistivity of 100,000 ohm-cm or greater, means for filling electron traps therein, means for propagating an r.f. acoustical pulse through said crystal, means for applying a second r.f. pulse of the same frequency to said crystal at a time Tau after the entry of said acoustic pulse so as to write said acoustic pulse as a stable pattern of trapped electrons having the same spatial variations as said acoustic pulse, and means for applying a third r.f. pulse having thE same frequency as said prior pulses to said crystal at a time T whereby said acoustic pulse is read out from the crystal at time T + Tau .
Claim 14
Dependent Claim
126 words
In a memory device for obtaining storage of information comprising a fully anion-compensated piezoelectric crystal having a resistivity of 100,000 ohm-cm or greater, means for filling electron traps therein, means for propagating an r.f. acoustical pulse through said crystal, means for applying a second r.f. pulse of the same frequency to said crystal at a time Tau after the entry of said acoustic pulse so as to write said acoustic pulse as a stable pattern of trapped electrons having the same spatial variations as said acoustic pulse, and means for applying a third r.f. pulse having thE same frequency as said prior pulses to said crystal at a time T whereby said acoustic pulse is read out from the crystal at time T + Tau .
Claim 15
Dependent Claim
54 words
A device for reading the information stored in the crystal of claim 4 comprising a source of laser light, means for directing said light onto said crystal containing said stored holograph, whereby said crystal diffracts said laser light in accordance with the information stored by said crystal, and means for detecting such diffracted light.
Claim 16
Independent Claim
162 words
A device for obtaining storage of information comprising a material containing defect sites on which electrons can be trapped and such traps can be subsequently ionized by electric fields, means for filling said electron traps, means for propagating an r.f. acoustic pulse having a frequency omega 1 through said material wherein said acoustic pulse serves as an information-bearing pulse, means for applying a second r.f. pulse of a frequency omega 2 to said material during the presence of said acoustic pulse so as to write said information-bearing pulse as a stable pattern of trapped electrons having the same spatial variations as said acoustic pulse so that the phase and amplitude of said acoustic pulse is retained in the material, and means for applying a d.c. pulse to said material simultaneously with the r.f. write pulse having the frequency omega 2 so that storage occurs at frequencies that are related by omega 2 omega 1/n, where n is an integer other than zero.
Claim 17
Independent Claim
162 words
A device for obtaining storage of information comprising a material containing defect sites on which electrons can be trapped and such traps can be subsequently ionized by electric fields, means for filling said electron traps, means for propagating an r.f. acoustic pulse having a frequency omega 1 through said material wherein said acoustic pulse serves as an information-bearing pulse, means for applying a second r.f. pulse of a frequency omega 2 to said material during the presence of said acoustic pulse so as to write said information-bearing pulse as a stable pattern of trapped electrons having the same spatial variations as said acoustic pulse so that the phase and amplitude of said acoustic pulse is retained in the material, and means for applying a d.c. pulse to said material simultaneously with the r.f. write pulse having the frequency omega 2 so that storage occurs at frequencies that are related by omega 2 omega 1/n, where n is an integer other than zero.
Claim 18
Dependent Claim
21 words
The device of claim 4 wherein said second r.f. pulse is very much shorter in duration than said first r.f. pulse.
Claim 19
Dependent Claim
35 words
The device of claim 4 including means for applying an r.f. pulse of the same frequency as said first r.f. pulse to said stored charge pattern so as to read out the stored acoustic pulse.
Claim 20
Dependent Claim
30 words
The device of claim 12 including means for applying a pulse at the frequency of said acoustic pulse to said material so as to read out said stored acoustic pulse.
Claim 21
Dependent Claim
35 words
The device of claim 12 including means for applying a second acoustic pulse of the same frequency as said first acoustic pulse to said material so as to read out the stored second r.f. pulse.
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) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |