US3715740A
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Optical mass memory
Assignee: Honeywell Inc
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Filing: 1971-08-30
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Granted: 1973-02-06
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Expires: 1991-08-30
Abstract
Abstract An optical mass memory of the Curie point writing type includes a separate read-out beam for checking written bits within fractions of microseconds after storage to ensure that the magnetization direction of the bit was properly stored.
Inventors
- 👤 F Schmit
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 01:01
CPC Classifications
G; G11; G11C; G11C13/00; G11C13/04; G11C13/06; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10502; G11B11/10515; G11B11/1055; G11B11/10576; G11B11/10595
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
290 words
An optical mass memory comprising: a ferromagnetic medium, motor means for providing motion of the ferromagnetic medium in a first direction, first light source means for producing a first light beam having an intensity sufficient to heat a region of the ferromagneTic medium to a temperature above the Curie temperature, second light source means for producing a second light beam angularly separated from the first light beam in the first direction and having an intensity insufficient to heat the region of the ferromagnetic medium to a temperature above the Curie temperature, the first and second light beams having a common pivot plane located between the first and second light source means and the ferromagnetic medium, light beam positioning means positioned at the common pivot plane for positioning the first and second light beams in a second direction essentially orthogonal to the first direction, focusing means for focusing the first and second light beams to a first and a second focused light spot respectively on the ferromagnetic medium, the second focused light spot being spatially separated in the first direction from the first light spot, modulator means for selectively transmitting the first light beam with an intensity sufficient to heat a region of the ferromagnetic medium to a temperature above the Curie temperature, and then attenuating the first light beam to an intensity insufficient to heat the region to a temperature above the Curie temperature, such that the region cools to a temperature below the Curie temperature and has a magnetization direction determined by a net magnetic field present at the location of the region, and detector means for receiving the second light beam from the region and for producing a magneto-optic signal indicative of the magnetization direction of the region.
Claim 2
Dependent Claim
290 words
An optical mass memory comprising: a ferromagnetic medium, motor means for providing motion of the ferromagnetic medium in a first direction, first light source means for producing a first light beam having an intensity sufficient to heat a region of the ferromagneTic medium to a temperature above the Curie temperature, second light source means for producing a second light beam angularly separated from the first light beam in the first direction and having an intensity insufficient to heat the region of the ferromagnetic medium to a temperature above the Curie temperature, the first and second light beams having a common pivot plane located between the first and second light source means and the ferromagnetic medium, light beam positioning means positioned at the common pivot plane for positioning the first and second light beams in a second direction essentially orthogonal to the first direction, focusing means for focusing the first and second light beams to a first and a second focused light spot respectively on the ferromagnetic medium, the second focused light spot being spatially separated in the first direction from the first light spot, modulator means for selectively transmitting the first light beam with an intensity sufficient to heat a region of the ferromagnetic medium to a temperature above the Curie temperature, and then attenuating the first light beam to an intensity insufficient to heat the region to a temperature above the Curie temperature, such that the region cools to a temperature below the Curie temperature and has a magnetization direction determined by a net magnetic field present at the location of the region, and detector means for receiving the second light beam from the region and for producing a magneto-optic signal indicative of the magnetization direction of the region.
Claim 3
Dependent Claim
290 words
An optical mass memory comprising: a ferromagnetic medium, motor means for providing motion of the ferromagnetic medium in a first direction, first light source means for producing a first light beam having an intensity sufficient to heat a region of the ferromagneTic medium to a temperature above the Curie temperature, second light source means for producing a second light beam angularly separated from the first light beam in the first direction and having an intensity insufficient to heat the region of the ferromagnetic medium to a temperature above the Curie temperature, the first and second light beams having a common pivot plane located between the first and second light source means and the ferromagnetic medium, light beam positioning means positioned at the common pivot plane for positioning the first and second light beams in a second direction essentially orthogonal to the first direction, focusing means for focusing the first and second light beams to a first and a second focused light spot respectively on the ferromagnetic medium, the second focused light spot being spatially separated in the first direction from the first light spot, modulator means for selectively transmitting the first light beam with an intensity sufficient to heat a region of the ferromagnetic medium to a temperature above the Curie temperature, and then attenuating the first light beam to an intensity insufficient to heat the region to a temperature above the Curie temperature, such that the region cools to a temperature below the Curie temperature and has a magnetization direction determined by a net magnetic field present at the location of the region, and detector means for receiving the second light beam from the region and for producing a magneto-optic signal indicative of the magnetization direction of the region.
Claim 4
Dependent Claim
290 words
An optical mass memory comprising: a ferromagnetic medium, motor means for providing motion of the ferromagnetic medium in a first direction, first light source means for producing a first light beam having an intensity sufficient to heat a region of the ferromagneTic medium to a temperature above the Curie temperature, second light source means for producing a second light beam angularly separated from the first light beam in the first direction and having an intensity insufficient to heat the region of the ferromagnetic medium to a temperature above the Curie temperature, the first and second light beams having a common pivot plane located between the first and second light source means and the ferromagnetic medium, light beam positioning means positioned at the common pivot plane for positioning the first and second light beams in a second direction essentially orthogonal to the first direction, focusing means for focusing the first and second light beams to a first and a second focused light spot respectively on the ferromagnetic medium, the second focused light spot being spatially separated in the first direction from the first light spot, modulator means for selectively transmitting the first light beam with an intensity sufficient to heat a region of the ferromagnetic medium to a temperature above the Curie temperature, and then attenuating the first light beam to an intensity insufficient to heat the region to a temperature above the Curie temperature, such that the region cools to a temperature below the Curie temperature and has a magnetization direction determined by a net magnetic field present at the location of the region, and detector means for receiving the second light beam from the region and for producing a magneto-optic signal indicative of the magnetization direction of the region.
Claim 5
Dependent Claim
55 words
The optical mass memory of claim 1 and further comprising: reference signal producing means for producing a reference signal representing the magnetization direction desired to be stored in the region, and signal comparing means for comparing the reference signal and the magneto-optic signal to determine whether the magnetization direction of the region was properly stored.
Claim 6
Dependent Claim
15 words
The optical mass memory of claim 1 wherein the ferromagnetic medium is manganese bismuth film.
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) | 1976-02-06 | 1976-08-07 | 1977-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-06 | 1980-08-07 | 1981-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-06 | 1984-08-07 | 1985-02-06 | $7700.00 | Window Closed / Lapsed |