US3774180A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ferromagnetic memory readout device
Assignee: Individual
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Filing: 1971-07-22
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Granted: 1973-11-20
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Expires: 1991-07-22
Abstract
Abstract A readout device for decoding the binary value stored in a ferromagnetic wire where the direction of propagation of a nucleated magnetic domain wall is indicative of the binary value stored in the memory. The readout device includes a magnetic source for nucleating a magnetic domain wall at one end of the wire and propagating it to the other end, and a pickup device with a split head arrangement for detecting the direction of propagation. The aforementioned Abstract is neither intended to define the invention of the application which, of course, is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
Inventors
- 👤 J Wiegand
- 👤 M Velinsky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:39
CPC Classifications
G; G06; G06K; G06K7/00; G06K7/08; G06K7/082; G06K7/087
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
137 words
A magnetic readout device for reading out information stored on a plurality of ferromagnetic wires each wire having the property of requiring a greater magnetic force for nucleating a magnetic domain wall than is required for propagating a magnetic domain wall through the wire and each wire having one end thereof more easily affected by the magnetic field than the rest of the wire thereby requiring a nucleating force less than the rest of the wire but greater than the propagating force, said readout device comprising: a. magnetic means for nucleating a magnetic domain wall at the more easily affected end of each of said wires and for propagating said domain wall along each of said wires; and b. sensing means for sensing the direction of propagation of said magnetic domain wall along each of said wires.
Claim 2
Dependent Claim
137 words
A magnetic readout device for reading out information stored on a plurality of ferromagnetic wires each wire having the property of requiring a greater magnetic force for nucleating a magnetic domain wall than is required for propagating a magnetic domain wall through the wire and each wire having one end thereof more easily affected by the magnetic field than the rest of the wire thereby requiring a nucleating force less than the rest of the wire but greater than the propagating force, said readout device comprising: a. magnetic means for nucleating a magnetic domain wall at the more easily affected end of each of said wires and for propagating said domain wall along each of said wires; and b. sensing means for sensing the direction of propagation of said magnetic domain wall along each of said wires.
Claim 3
Dependent Claim
39 words
The device of claim 1 further including additional magnetic means for removing residual magnetism in each of said ferromagnetic wires and initializing said wires in a first magnetic state, the two magnetic means positioned to magnetically oppose each other.
Claim 4
Dependent Claim
14 words
A device as in claim 2 wherein the two magnetic means are bar magnets.
Claim 5
Dependent Claim
26 words
A device as in claim 2 wherein the two magnetic means are spaced apart from each other such that a point of zero force exists therebetween.
Claim 6
Dependent Claim
25 words
A device as in claim 1 wherein said magnetic means is placed in a direction opposing the direction of existing magnetism in said ferromagnetic wires.
Claim 7
Dependent Claim
31 words
A device as in claim 1 wherein said sensinG means comprises first and second induction coils capable of having an electric pulse induced therein as said magnetic domain wall passes it.
Claim 8
Dependent Claim
103 words
A device as in claim 1 wherein said sensing means further includes a magnetic core having first and second sections each with a gap therein and including a common energizing means. 8 A device as in claim 1 wherein said sensing means includes a magnetic core having a base portion, a first and second arm extending therefrom and a common arm extending from said base and spaced between said first and second arms, a first gap between said common arm and said first arm, a second gap between said common arm and said second arm, and energizing means contained in said common arm.
Claim 9
Dependent Claim
27 words
A device as in claim 1 wherein said magnetic means has a force capable of producing a magnetic field varying in strength from 0.16 to 25 oersteds.
Claim 10
Dependent Claim
28 words
A device as in claim 1 further including a housing containing said magnetic means and said sensing means and is capable of accommodating said ferromagnetic wires passing therethrough.
Claim 11
Dependent Claim
17 words
A device as in claim 10 wherein said housing is in the form of a movable probe.
Claim 12
Dependent Claim
26 words
A device as in claim 1 wherein said sensing means further includes electronic logic means for decoding the direction of propagation of said magnetic domain wall.
Claim 13
Dependent Claim
64 words
A device as in claim 1 wherein said sensing means includes first and second induction coil means and wherein a first sequence of electric pulses is induced as said magnetic domain wall moves along said ferromagnetic wires in a first direction and a second sequence of electric pulses is induced as said magnetic domain wall moves along said ferromagnetic wires in an opposite direction.
Claim 14
Dependent Claim
20 words
A device as in claim 10 wherein said housing includes means for accepting the ferromagnetic wires in only one direction.
Claim 15
Dependent Claim
21 words
A device as in claim 1 wherein said easily affected end has a lower reluctance than the rest of the wire.
Claim 16
Dependent Claim
39 words
A device as in claim 1 wherein said easily affected end is relatively shorter than the opposite end such that the midpoint of the wire is spatially offset in an axial direction from the midpoint of the magnetic field.
Claim 17
Independent Claim
120 words
A method of reading out information stored in a memory comprised of a plurality of ferromagnetic wires having the property of requiring a greater magnetic force for nucleating a magnetic domain wall than is required for propagating a domain wall in each of said wires, each of said wires having one end thereof more easily affectd by the magnetic field than the rest of the wire, including the steps of: a. nucleating a magnetic domain wall in the more easily affected end in each of said wires; b. propagating said magnetic domain wall along each of said wires; c. sensing the direction of propagation of said magnetic domain wall along each of said wires; and d. decoding the direction sensed.
Claim 18
Independent Claim
120 words
A method of reading out information stored in a memory comprised of a plurality of ferromagnetic wires having the property of requiring a greater magnetic force for nucleating a magnetic domain wall than is required for propagating a domain wall in each of said wires, each of said wires having one end thereof more easily affectd by the magnetic field than the rest of the wire, including the steps of: a. nucleating a magnetic domain wall in the more easily affected end in each of said wires; b. propagating said magnetic domain wall along each of said wires; c. sensing the direction of propagation of said magnetic domain wall along each of said wires; and d. decoding the direction sensed.
Claim 19
Dependent Claim
40 words
The method as in claim 17 wherein said steps of nucleating and propagating includes the step of magnetizing said ferromagnetic wires in a first direction and passing said wires through a magnetic field of sufficient magnitude in an opposing direction.
Claim 20
Dependent Claim
41 words
The method as in claim 18 wherein said step of sensing further comprises the steps of inducing a sequence of electric pulses in accordance with the direction of propagation of said magnetic domain wall and detecting the sequence of pulses induced.
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) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |