US5155644A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Yoke thin film magnetic head constructed to avoid Barkhausen noises
Assignee: Sharp Corp
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Filing: 1991-04-22
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Granted: 1992-10-13
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Expires: 2011-04-22
Abstract
Abstract The yoke thin film magnetic head according to the present invention includes yokes for leading the magnetic flux of signals generated from the magnetic recording medium up to the magnetic resistance effect element, which yokes are made of sputtered films having compressive stress therein. Therefore, the internal stress in the yokes which cause bad influences upon magnetic properties of the magnetic resistance effect element can be negated or reduced, with less Barkhausen noises produced.
Inventors
- 👤 Tohru Kira
- 👤 Kozi Otsuka
- 👤 Kazuyoshi Imae
- 👤 Mitsuhiko Yoshikawa
- 👤 Kengo Shiiba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:03
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; G11B5/3906; G11B5/3916; G11B5/3919; G11B5/3922; G11B5/3925; G11B5/31; G11B5/3109; G11B5/3113
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
219 words
A yoke thin film magnetic head which comprises: magneto-resistive means for detecting a magnetic field of signals produced in a magnetic record medium as the change in resistance, said magneto-resistive means including an element having a substantially flat surface with a longitudinal direction and a width, yoke means defining a head gap and for leading magnetic flux from said head gap to said magneto-resistive element, said yoke means including at least two yoke members spaced from each other each of said yoke members having a portion extending the longidudinal direction and overlying a portion of said magneto-resistive element, DC magnetic field applying means for applying a desired weak magnetic field to said magneto-resistive element in said longitudinal direction, said DC magnetic field applying means having portions thereof overlying portions of said magneto-resistive element substantially perpendicular to the longitudinal direction, conductor means for applying a desired biasing magnetic field to said magneto-resistive element over said width of said element, said conductor means being located overlying said DC magnetic field applying means and adjacent said magneto-resistive element, and said magneto-resistive element having an average inclination angle of an easy magnetization axis in said magneto-resistive element inclined along the longitudinal direction between 5°-20° with respect to said longitudinal direction of said magneto-resistive element so that Barkhausen noises of the head are suppressed.
Claim 2
Dependent Claim
219 words
A yoke thin film magnetic head which comprises: magneto-resistive means for detecting a magnetic field of signals produced in a magnetic record medium as the change in resistance, said magneto-resistive means including an element having a substantially flat surface with a longitudinal direction and a width, yoke means defining a head gap and for leading magnetic flux from said head gap to said magneto-resistive element, said yoke means including at least two yoke members spaced from each other each of said yoke members having a portion extending the longidudinal direction and overlying a portion of said magneto-resistive element, DC magnetic field applying means for applying a desired weak magnetic field to said magneto-resistive element in said longitudinal direction, said DC magnetic field applying means having portions thereof overlying portions of said magneto-resistive element substantially perpendicular to the longitudinal direction, conductor means for applying a desired biasing magnetic field to said magneto-resistive element over said width of said element, said conductor means being located overlying said DC magnetic field applying means and adjacent said magneto-resistive element, and said magneto-resistive element having an average inclination angle of an easy magnetization axis in said magneto-resistive element inclined along the longitudinal direction between 5°-20° with respect to said longitudinal direction of said magneto-resistive element so that Barkhausen noises of the head are suppressed.
Claim 3
Dependent Claim
17 words
The magnetic head according to claim 1 wherein said yoke means further includes a third yoke member.
Claim 4
Dependent Claim
23 words
The magnetic head according to claim 2 wherein said conductor means and said two yoke members are formed on said third yoke member.
Claim 5
Dependent Claim
33 words
The magnetic head according to claim 3 wherein said head gap is in a space between an edge of one of said two yoke members and an edge of said third yoke member.
Claim 6
Dependent Claim
15 words
The magnetic head according to claim 4 wherein said head gap is approximately 0.1-0.3 um.
Claim 7
Dependent Claim
18 words
The magnetic head according to claim 1 wherein said magneto-resistive element is in a single magnetic domain state.
Claim 8
Dependent Claim
21 words
The magnetic head of claim 6 wherein said DC magnetic field applying means is a ferro-magnetic film having high coercive force.
Claim 9
Dependent Claim
35 words
The magnetic head of claim 1 wherein the average inclination angle of the easy magnetization axis, in said magneto-resistive element is inclined over than 5° with respect to the width respect to the longitudinal direction.
Claim 10
Dependent Claim
63 words
The magnetic head of claim 8, wherein at specific points in the magneto resistive element the easy magnetization axis is inclined at different angles so that the average inclination angle of an easy magnetization axis in said magneto resistive element is inclined at an angle with respect to said longitudinal direction of said magneto-resistive element which angle is inclined over than 5° .
Claim 11
Dependent Claim
30 words
The magnetic head of claim 1 wherein the average inclination angle of the easy magnetization axis, in said magneto-resistive element is inclined under 20° with respect to the longitudinal direction.
Claim 12
Dependent Claim
46 words
The magnetic head of claim 10, wherein at specific points in the magneto resistive element the easy magnetization axis is inclined at different angles so that the average inclination angle of an easy magnetization axis in said magneto resistive element is inclined at under 20° .
Claim 13
Dependent Claim
27 words
The magnetic head of claim 1 wherein said DC magnetic field applying means includes two ferro-magnetic films each film located at opposite ends of the magnetic-resistive element.
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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) | 1995-10-13 | 1996-04-13 | 1996-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-10-13 | 2000-04-13 | 2000-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-10-13 | 2004-04-13 | 2004-10-13 | $7700.00 | Window Closed / Lapsed |