US5388014A
Expired / Lapsed
US
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Apparatus and method of sensing the position of a magnetic head
Assignee: HP Inc
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Filing: 1993-09-10
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Granted: 1995-02-07
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Expires: 2013-09-10
Abstract
Abstract An apparatus and method for determining the position of a magnetic head from a magnetic track in a storage medium. The magnetic head includes two magneto-resistive elements electrically separated by an insulative layer; current leads for biasing the MR elements and rotating the magnetization of the MR elements in opposite directions that are transverse from the respective axes of the elements; and circuitry to monitor the resistance changes of the respective MR elements and producing respective first and second output signals and to manipulate the output signals to provide an indication of the cross-track position of the magnetic head relative to the magnetic track.
Inventors
- 👤 James A. Brug
- 👤 Richard H. Henze
- 👤 Steven L. Naberhuis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 01:58
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/54; G11B5/55; G11B5/5521; G11B5/5526; G11B5/553; G11B5/5547; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; G11B5/3906; G11B5/3945; G11B5/3948; G11B5/488; G11B2005/0002; G11B2005/0005; G11B2005/001; G11B2005/0013; G11B2005/0016; G11B2005/0018; G11B5/3951; G11B5/3954; G11B5/58; G11B5/584; G11B5/596; G11B5/59683
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
140 words
An apparatus for providing a position signal that indicates the cross-track position of a magnetic head relative to a selected magnetic track, the apparatus comprising: a first magneto-resistive (MR) element in the magnetic head to sense a portion of the recorded information in the magnetic track, the element having a longitudinal direction; a second MR element in the magnetic head, insulated from the first MR element, to sense substantially the same cross-track portion of the magnetic track, the second element having a longitudinal direction; current means for applying a biasing current for and producing an output signal from each MR element, the two biasing currents rotating the magnetization of the MR elements in opposing directions that are transverse from the respective longitudinal directions of the MR elements; and position decoding means manipulating the output signals to establish the position signal.
Claim 2
Independent Claim
140 words
An apparatus for providing a position signal that indicates the cross-track position of a magnetic head relative to a selected magnetic track, the apparatus comprising: a first magneto-resistive (MR) element in the magnetic head to sense a portion of the recorded information in the magnetic track, the element having a longitudinal direction; a second MR element in the magnetic head, insulated from the first MR element, to sense substantially the same cross-track portion of the magnetic track, the second element having a longitudinal direction; current means for applying a biasing current for and producing an output signal from each MR element, the two biasing currents rotating the magnetization of the MR elements in opposing directions that are transverse from the respective longitudinal directions of the MR elements; and position decoding means manipulating the output signals to establish the position signal.
Claim 3
Dependent Claim
31 words
An apparatus as recited in claim 1 further comprising an electrically insulating layer such that the first and second MR elements are fabricated on opposite sides of the electrically insulative layer.
Claim 4
Dependent Claim
26 words
An apparatus as recited in claim 2 wherein the first and the second MR elements are substantially parallel and substantially equal in dimensions to each other.
Claim 5
Dependent Claim
31 words
An apparatus as recited in claim 1, wherein each biasing current flows along the longitudinal direction of its corresponding MR element, and the two biasing currents are in the same direction.
Claim 6
Dependent Claim
26 words
An apparatus as recited in claim 1, wherein the position signal is related to the quotient of the sum and the difference of the output signals.
Claim 7
Dependent Claim
20 words
An apparatus as recited in claim 1, wherein the position signal is related to the sum of the output signals.
Claim 8
Dependent Claim
37 words
An apparatus as recited in claim 1 wherein: the output signals are indicative of the change in resistance of their respective MR elements; and the position decoding means, based on the output signals, computes the position signal.
Claim 9
Dependent Claim
28 words
An apparatus as recited in claim 5 wherein the position decoding means comprises means for generating the quotient from the sum and the difference of the output signals.
Claim 10
Independent Claim
121 words
A method of providing a position signal that indicates the cross-track position of a magnetic head relative to a selected magnetic track, the method comprising the steps of: fabricating the magnetic head with a first magneto-resistive (MR) element and a second MR element insulated from the first MR element, each element having a longitudinal direction, both elements sensing substantially the same cross-track portion of the magnetic track; applying a biasing current to each MR element for rotating the magnetization of the MR elements in opposing directions that are transverse from the respective longitudinal directions of the MR elements; producing an output signal from each of said first and second MR elements; and manipulating the output signals to establish the position signal.
Claim 11
Independent Claim
121 words
A method of providing a position signal that indicates the cross-track position of a magnetic head relative to a selected magnetic track, the method comprising the steps of: fabricating the magnetic head with a first magneto-resistive (MR) element and a second MR element insulated from the first MR element, each element having a longitudinal direction, both elements sensing substantially the same cross-track portion of the magnetic track; applying a biasing current to each MR element for rotating the magnetization of the MR elements in opposing directions that are transverse from the respective longitudinal directions of the MR elements; producing an output signal from each of said first and second MR elements; and manipulating the output signals to establish the position signal.
Claim 12
Dependent Claim
40 words
A method as recited in claim 9 wherein the step of fabricating further comprises the step of fabricating an electrically insulating layer such that the first and second MR elements are fabricated on opposite sides of the electrically insulative layer.
Claim 13
Dependent Claim
26 words
A method as recited in claim 9 wherein the first and the second MR elements are substantially parallel and substantially equal in dimensions to each other.
Claim 14
Dependent Claim
31 words
A method as recited in claim 9, wherein each biasing current is along the longitudinal direction of its corresponding MR element, and the two biasing currents are in the same direction.
Claim 15
Dependent Claim
35 words
A method as recited in claim 9, wherein the step of manipulating further comprises the step of forming the quotient from the sum and the difference of the output signals to form the position signal.
Claim 16
Dependent Claim
29 words
A method as recited in claim 9, wherein the step of manipulating further comprises the step of forming the sum of the output signals to form the position signal.
Claim 17
Dependent Claim
21 words
A method as recited in claim 9, wherein: the output signals are indicative of the resistances of their respective MR elements.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-02-06 | 1998-08-08 | 1999-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-02-06 | 2002-08-08 | 2003-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-02-06 | 2006-08-08 | 2007-02-07 | $7700.00 | Window Closed / Lapsed |