US3836896A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Non-volatile magnetic domain device having binary valued bias field excitation
Assignee: International Business Machines Corp
•
Filing: 1972-06-29
•
Granted: 1974-09-17
•
Expires: 1992-06-29
Abstract
Abstract A packaged magnetic domain device provided with a bias magnetic field whose magnitude is adjustable to one of two different values for domain formation and domain erasure, respectively. The domain devices are packaged with a permanent magnet and an electromagnet whose additive magnetic fields constitute the bias field. Additional provision is made in the same package for a pair of orthogonal in-plane switching magnetic fields for domain propagation. Thermocouple means within the package and adjacent the magnetic domain chips monitors chip temperature and produces a proportional signal to control the electromagnet to maintain constant magnetic domain bubble size irrespective of temperature variations.
Inventors
- 👤 A Rifkin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:44
CPC Classifications
G; G11; G11C; G11C19/00; G11C19/02; G11C19/08; G11C19/085
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
148 words
A magnetic domain device comprising: a magnetic domain device chip, a permanent magnet surrounding said chip and providing a biaS magnetic field along an axis perpendicular to said chip, an electromagnet coil surrounding said chip and adjacent said permanent magnet and oriented to provide when excited a controllable magnetic field along said axis, and a binary valued current source for providing a current of two different amplitudes for application to said coil, said permanent magnet and said coil in response to one of said two different current amplitudes providing a total bias magnet field having a value sustaining the generation and propagation of magnetic domains in said chip and providing a total bias magnetic field in response to the other of said two different current amplitudes having a value causing the collapse of said magnetic domains and precluding the generation and propagation of magnetic domains in said chip.
Claim 2
Dependent Claim
148 words
A magnetic domain device comprising: a magnetic domain device chip, a permanent magnet surrounding said chip and providing a biaS magnetic field along an axis perpendicular to said chip, an electromagnet coil surrounding said chip and adjacent said permanent magnet and oriented to provide when excited a controllable magnetic field along said axis, and a binary valued current source for providing a current of two different amplitudes for application to said coil, said permanent magnet and said coil in response to one of said two different current amplitudes providing a total bias magnet field having a value sustaining the generation and propagation of magnetic domains in said chip and providing a total bias magnetic field in response to the other of said two different current amplitudes having a value causing the collapse of said magnetic domains and precluding the generation and propagation of magnetic domains in said chip.
Claim 3
Dependent Claim
16 words
The device defined in claim 1 wherein one of said two different current amplitudes is zero.
Claim 4
Dependent Claim
39 words
The device defined in claim 1 and further including means for sensing the temperature of said chip and for providing a signal which is a function of said temperature, and means for applying said signal to said electromagnet coil.
Claim 5
Dependent Claim
24 words
The device defined in claim 3 wherein said means for sensing is a thermocouple located adjacent said chip and surrounded by said permanent magnet.
Claim 6
Dependent Claim
93 words
The device defined in claim 4 wherein said permanent magnet comprises a pair of permanent bar magnets and a pair of sheets of magnetic material, said chip being located between said bar magnets, and said sheets of magnetic material extending between and across said bar magnets and across said coil, and further including a plurality of conductive pins, said coil and said thermocouple being connected to respective ones of said pins, one of said sheets of magnetic material being apertured to permit penetration by said pins without establishing electrical contact with said pins.
Claim 7
Dependent Claim
50 words
The device defined in claim 1 wherein said permanent magnet comprises: a pair of permanent bar magnets and a pair of sheets of magnetic material, said chip being located between said bar magnets, and said sheets of magnetic material extending between and across said bar magnets and across said coil.
Claim 8
Dependent Claim
29 words
The device defined in claim 6 and further including a splitable closed container having engageable mating surfaces for supportably enclosing said bar magnets and said sheets of magnetic materials.
Claim 9
Dependent Claim
47 words
The device defined in claim 6 and further including a plurality of conductive pins, said coil being connected to respective ones of said pins, and one of said sheets of magnetic material being apertured to permit penetration by said pins without establishing electrical contact with said pins.
References Cited (Backward Citations)
US3631417A
Cited
US3711841A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-16 | 1978-03-18 | 1978-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-16 | 1982-03-18 | 1982-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-16 | 1986-03-18 | 1986-09-17 | $7700.00 | Window Closed / Lapsed |