Patent US5041922A successfully refreshed from Google Patents.
US5041922A
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Magnetic recording medium having magnetic storage and saturable layers, and apparatus and method using the medium
Assignee: Ampex Corp
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Filing: 1990-07-23
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Granted: 1991-08-20
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Expires: 2010-07-23
Abstract
Abstract Magnetic record media are described that have an overlying or underlying magnetically saturable high permeability keeper layer in addition to a high coervicity magnetic layer in which magnetic signals are stored. These media are used in magnetic signal processing devices whose transducers are capable of generating a keeper layer-saturating bias flux. In signal reproduction the bias flux magnetically forms a saturation zone in the nature of virtual gap in the keeper layer that directs signal flux between the media and the transducer.
Inventors
- 👤 Roger W. Wood
- 👤 Beverley R. Gooch
- 👤 Rex Niedermeyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:05
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/02; G11B5/09; G11B5/62; G11B5/64; G11B5/66; G11B5/672; G11B5/74
Claims Analysis
Total Claims: 43
Claim 1
Independent Claim
65 words
A magnetic recording medium comprising; (a) a nonmagnetic substrate; (b) a magnetically coercive material disposed on said substrate for storing magnetic signals; and (c) a magnetically permeable, magnetically saturable material disposed on the substrate so as to effect the storage of said magnetic signals in said magnetically coercive material with preferred axes of magnetization that are oriented substantially parallel to the surface of the substrate.
Claim 2
Dependent Claim
65 words
A magnetic recording medium comprising; (a) a nonmagnetic substrate; (b) a magnetically coercive material disposed on said substrate for storing magnetic signals; and (c) a magnetically permeable, magnetically saturable material disposed on the substrate so as to effect the storage of said magnetic signals in said magnetically coercive material with preferred axes of magnetization that are oriented substantially parallel to the surface of the substrate.
Claim 3
Dependent Claim
36 words
The magnetic recording medium of claim 1 wherein said magnetically coercive material is disposed on said substrate in a first layer and said magnetically permeable material is disposed on said substrate in a second discrete layer.
Claim 4
Dependent Claim
25 words
The magnetic recording medium of claim 2 wherein the layer of magnetically permeable, magnetically saturable material overlies the magnetically coercive layer relative to said substrate.
Claim 5
Dependent Claim
25 words
The magnetic recording medium of claim 2 wherein the layer of magnetically permeable, magnetically saturable material underlies the magnetically coercive layer relative to said substrate.
Claim 6
Dependent Claim
59 words
The magnetic recording medium of claim 2 wherein the materials and relative thicknesses of the layer of magnetically permeable, magnetically saturable material and the magnetically coercive layer are such that a flux required to saturate the layer of magnetically permeable, magnetically saturable material is less than a flux required to affect magnetic signals stored in the magnetically coercive layer.
Claim 7
Dependent Claim
19 words
The magnetic recording medium of claim 2 wherein the layer of magnetically permeable, magnetically saturable material is a keeper.
Claim 8
Dependent Claim
73 words
In a magnetic signal processing apparatus having a magnetic record medium in which signals are received and stored in a magnetically coercive layer and a magnetic transducer in closely spaced relationship to the surface of the medium, the improvement wherein the magnetic record medium includes a magnetically permeable, magnetically saturable material and the transducer has means associated therewith for generating a saturating magnetic bias flux directed by the transducer into said saturable material.
Claim 9
Dependent Claim
73 words
In a magnetic signal processing apparatus having a magnetic record medium in which signals are received and stored in a magnetically coercive layer and a magnetic transducer in closely spaced relationship to the surface of the medium, the improvement wherein the magnetic record medium includes a magnetically permeable, magnetically saturable material and the transducer has means associated therewith for generating a saturating magnetic bias flux directed by the transducer into said saturable material.
Claim 10
Dependent Claim
20 words
The apparatus of claim 7 wherein said saturable material is disposed on said magnetic record medium in a discrete layer.
Claim 11
Dependent Claim
47 words
The apparatus of claim 8 wherein the materials and relative thicknesses of the saturable layer and the magnetically coercive layer are such that the flux required to saturate the saturable layer is less than the flux required to affect magnetic signals stored in the magnetically coercive layer.
Claim 12
Dependent Claim
31 words
The apparatus of claim 7 wherein the magnetic signals are stored in the magnetically coercive layer with their axes of magnetization substantially parallel to the plane of the magnetically coercive layer.
Claim 13
Dependent Claim
34 words
The apparatus of claim 10 wherein the saturable material is disposed in a discrete layer which overlies the magnetically coercive layer on the side of said coercive layer which is closest to said transducer.
Claim 14
Dependent Claim
30 words
The apparatus of claim 10 wherein the saturable material is disposed in a discrete layer located on the side of the magnetically coercive layer that is remote from said transducer.
Claim 15
Dependent Claim
54 words
The apparatus of claim 7 wherein the signals are stored with their axes of magnetization substantially perpendicular to the plane of the magnetically coercive layer and the saturable material is disposed in a discrete layer which overlies the magnetically coercive layer on the side of said coercive layer which is closest to said transducer.
Claim 16
Dependent Claim
15 words
The apparatus of claim 7 wherein the bias flux is generated by a direct-current source.
Claim 17
Dependent Claim
16 words
The apparatus of claim 7 wherein the bias flux is generated by an alternating current source.
Claim 18
Dependent Claim
85 words
A magnetic signal processing apparatus comprising: (a) a magnetic record medium having a magnetically coercive material for receiving and storing signals and a magnetically permeable, magnetically saturable material; (b) a magnetic transducer positioned relative to the surface of the medium for transferring signals with respect to the medium; (c) means for relatively moving the medium and the transducer; and (d) means for generating a bias field in the transducer which saturates a portion of said saturable material during signal transfers between the medium and transducer.
Claim 19
Dependent Claim
85 words
A magnetic signal processing apparatus comprising: (a) a magnetic record medium having a magnetically coercive material for receiving and storing signals and a magnetically permeable, magnetically saturable material; (b) a magnetic transducer positioned relative to the surface of the medium for transferring signals with respect to the medium; (c) means for relatively moving the medium and the transducer; and (d) means for generating a bias field in the transducer which saturates a portion of said saturable material during signal transfers between the medium and transducer.
Claim 20
Dependent Claim
29 words
The apparatus of claim 16 wherein the signals are stored in the magnetically coercive material with their axes of magnetization substantially parallel to the plane of the record medium.
Claim 21
Dependent Claim
21 words
The apparatus of claim 16 wherein said coercive material and said saturable material are disposed in respective layers on a substrate.
Claim 22
Dependent Claim
18 words
The apparatus of claim 18 wherein the saturable layer overlies the magnetically coercive layer relative to said substrate.
Claim 23
Dependent Claim
19 words
The apparatus of claim 18 wherein the saturable layer relative to said substrate underlies the magnetically coercive magnetic layer.
Claim 24
Dependent Claim
38 words
The apparatus of claim 18 wherein the signals are stored with their axes of magnetization substantially perpendicular to the plane of the magnetically coercive layer, and the saturable layer overlies the magnetically coercive layer relative to said substrate.
Claim 25
Dependent Claim
46 words
The apparatus of claim 18 wherein the materials and relative thicknesses of the saturable layer and the magnetically coercive layer are such that the flux required to saturate the saturable layer is less than the flux required to erase magnetic signals from the magnetically coercive layer.
Claim 26
Dependent Claim
25 words
The apparatus of claim 16 wherein the means for generating a bias field in the transducer is a current threading a winding on the transducer.
Claim 27
Dependent Claim
88 words
In a method of processing magnetic signals using a magnetic transducer having a physical transducing gap and a closely spaced magnetic storage medium having a magnetically coercive layer with respect to which the signals are transferred, the improvement comprising: (a) providing the magnetic storage medium with a magnetically permeable, magnetically saturable material; and (b) generating a magnetic bias flux in the transducer during signal transfers with respect to the magnetic storage medium that saturates a portion of the magnetically permeable, magnetically saturable material proximate of the transducing gap.
Claim 28
Dependent Claim
88 words
In a method of processing magnetic signals using a magnetic transducer having a physical transducing gap and a closely spaced magnetic storage medium having a magnetically coercive layer with respect to which the signals are transferred, the improvement comprising: (a) providing the magnetic storage medium with a magnetically permeable, magnetically saturable material; and (b) generating a magnetic bias flux in the transducer during signal transfers with respect to the magnetic storage medium that saturates a portion of the magnetically permeable, magnetically saturable material proximate of the transducing gap.
Claim 29
Dependent Claim
24 words
The method of claim 24 wherein the bias flux is below a level sufficient to affect the signals stored by the magnetic storage medium.
Claim 30
Dependent Claim
20 words
The method of claim 24 wherein the bias flux is generated by application of a direct current to the transducer.
Claim 31
Dependent Claim
20 words
The method of claim 24 wherein the bias field is generated by application of an alternating current to the transducer.
Claim 32
Dependent Claim
93 words
A magnetic recording medium comprising: a nonmagnetic substrate; a first layer of magnetic material having a relatively low magnetic permeability and a relatively high magnetic coercivity for storing information therein as magnetic states; and a second layer of magnetic material having a relatively high magnetic permeability and a relatively low magnetic coercivity and whose thickness relative to that of said first layer is such that the density of magnetic flux required to saturate said second layer is less than the density of magnetic flux required to alter magnetic states in said first layer.
Claim 33
Dependent Claim
93 words
A magnetic recording medium comprising: a nonmagnetic substrate; a first layer of magnetic material having a relatively low magnetic permeability and a relatively high magnetic coercivity for storing information therein as magnetic states; and a second layer of magnetic material having a relatively high magnetic permeability and a relatively low magnetic coercivity and whose thickness relative to that of said first layer is such that the density of magnetic flux required to saturate said second layer is less than the density of magnetic flux required to alter magnetic states in said first layer.
Claim 34
Dependent Claim
92 words
A magnetic recording medium for use in a recording/reproducing system of the type in which a bias flux is applied to the recording medium to define a signal transfer zone, comprising: a nonmagnetic substrate; a magnetically coercive layer whose magnetization is controlled to store magnetic signals; and a layer of magnetically permeable material having a thickness such that a portion of said layer becomes saturated by an applied bias flux whose magnitude is less than that required to alter the magnetization of said coercive layer to thereby establish a signal transfer zone.
Claim 35
Dependent Claim
92 words
A magnetic recording medium for use in a recording/reproducing system of the type in which a bias flux is applied to the recording medium to define a signal transfer zone, comprising: a nonmagnetic substrate; a magnetically coercive layer whose magnetization is controlled to store magnetic signals; and a layer of magnetically permeable material having a thickness such that a portion of said layer becomes saturated by an applied bias flux whose magnitude is less than that required to alter the magnetization of said coercive layer to thereby establish a signal transfer zone.
Claim 36
Dependent Claim
73 words
A magnetic recording medium for use in a recording/reproducing system in which magnetic information is transferred between a transducer and the record medium, comprising: a nonmagnetic substrate; a layer of magnetically coercive material in which the magnetic information is stored; and a magnetically permeable material disposed on the substrate in a manner such that material becomes selectively saturated during the transfer of information between a transducer and the layer of magnetically coercive material.
Claim 37
Dependent Claim
73 words
A magnetic recording medium for use in a recording/reproducing system in which magnetic information is transferred between a transducer and the record medium, comprising: a nonmagnetic substrate; a layer of magnetically coercive material in which the magnetic information is stored; and a magnetically permeable material disposed on the substrate in a manner such that material becomes selectively saturated during the transfer of information between a transducer and the layer of magnetically coercive material.
Claim 38
Dependent Claim
25 words
The magnetic recording medium of claim 30 wherein said magnetically permeable material is disposed in a discrete layer that is contiguous with said coercive layer.
Claim 39
Dependent Claim
45 words
The magnetic recording medium of claim 30 wherein the thickness of said layer of magnetically permeable material is such that a portion of said layer becomes saturated by a flux whose magnitude is less than that required to alter the magnetization of said coercive layer.
Claim 40
Dependent Claim
71 words
A magnetic recording medium comprising: a nonmagnetic substrate; a first layer of magnetic material for storing magnetically defined information therein; and a second layer of magnetic material having a magnetic permeability and a thickness relative to that of said first layer such that the magnitude of magnetic flux required to saturate said second layer is less than the magnitude of magnetic flux required to alter information stored in said first layer.
Claim 41
Dependent Claim
71 words
A magnetic recording medium comprising: a nonmagnetic substrate; a first layer of magnetic material for storing magnetically defined information therein; and a second layer of magnetic material having a magnetic permeability and a thickness relative to that of said first layer such that the magnitude of magnetic flux required to saturate said second layer is less than the magnitude of magnetic flux required to alter information stored in said first layer.
Claim 42
Dependent Claim
116 words
In a method of processing magnetic signals using a magnetic transducer having a physical transducing gap positioned to transfer the signals with respect to a magnetic storage medium having a magnetically coercive layer whose magnetization is altered to store information and with respect to which the signals are transferred, the improvement comprising: (a) providing the magnetic storage medium with a layer of magnetically permeable material capable of selective establishment of adjacent areas of different permeabilities; and (b) generating a magnetic bias flux during signal transfers between the transducer and the magnetically coercive layer productive to establish adjacent areas of different permeabilities at a portion of the layer of magnetically permeable material proximate of the transducing gap.
Claim 43
Dependent Claim
116 words
In a method of processing magnetic signals using a magnetic transducer having a physical transducing gap positioned to transfer the signals with respect to a magnetic storage medium having a magnetically coercive layer whose magnetization is altered to store information and with respect to which the signals are transferred, the improvement comprising: (a) providing the magnetic storage medium with a layer of magnetically permeable material capable of selective establishment of adjacent areas of different permeabilities; and (b) generating a magnetic bias flux during signal transfers between the transducer and the magnetically coercive layer productive to establish adjacent areas of different permeabilities at a portion of the layer of magnetically permeable material proximate of the transducing gap.
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) | 1994-08-19 | 1995-02-18 | 1995-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-08-19 | 1999-02-18 | 1999-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-08-19 | 2003-02-18 | 2003-08-20 | $7700.00 | Window Closed / Lapsed |