Patent US4524401A successfully refreshed from Google Patents.
US4524401A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic transducer head utilizing magneto resistance effect with a bias field and partial saturation
Assignee: Sony Corp
•
Filing: 1981-12-22
•
Granted: 1985-06-18
•
Expires: 2001-12-22
Abstract
Abstract A magnetic transducer head utilizing a thin film magneto-resistance effect element is disclosed in which the amount of a DC bias magnetic field is so selected that only the end portion of the thin film magneto-resistance effect element serving as a contact surface with a magnetic medium is effectively given with sensitivity and the element is saturated in the vicinity of its central portion in its width direction.
Inventors
- 👤 Hiroyuki Uchida
- 👤 Takehiro Nagaki
- 👤 Shigeyoshi Imakoshi
- 👤 Yutaka Soda
- 👤 Junkichi Sugita
- 👤 Tetsuo Sekiya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:49
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
185 words
A magnetic transducer head utilizing magneto resistance effect, comprising: a thin film magneto resistance effect element having an elongated edge arranged to closely confront a record track of a magnetic recording medium for scanning coupling with a signal recorded on the record track, said elongated edge being elongated in a longitudinal direction, current supplying means connected with said element to produce a current flow in the longitudinal direction in said element, biasing means coupled with said element to apply a D.C. bias magnetic field to said element, and means comprising the configuration of said element and the disposition of said elongated edge relative to said biasing means such that a demagnetizing field is produced which is relatively intense in a first region of said element at said elongated edge and is relatively less intense in a second region of said element remote from said elongated edge, with said D.C. bias magnetic field being of a strength to saturate said element at the second region thereof while the first region remains sensitive to a signal magnetic field from said record track of the magnetic recording medium.
Claim 2
Dependent Claim
185 words
A magnetic transducer head utilizing magneto resistance effect, comprising: a thin film magneto resistance effect element having an elongated edge arranged to closely confront a record track of a magnetic recording medium for scanning coupling with a signal recorded on the record track, said elongated edge being elongated in a longitudinal direction, current supplying means connected with said element to produce a current flow in the longitudinal direction in said element, biasing means coupled with said element to apply a D.C. bias magnetic field to said element, and means comprising the configuration of said element and the disposition of said elongated edge relative to said biasing means such that a demagnetizing field is produced which is relatively intense in a first region of said element at said elongated edge and is relatively less intense in a second region of said element remote from said elongated edge, with said D.C. bias magnetic field being of a strength to saturate said element at the second region thereof while the first region remains sensitive to a signal magnetic field from said record track of the magnetic recording medium.
Claim 3
Dependent Claim
28 words
A magnetic transducer head according to claim 1 with a width dimension of said element at right angles to the longitudinal direction being at least about five micrometers.
Claim 4
Dependent Claim
36 words
A magnetic transducer head according to claim 1 with said biasing means having a first elongated magnetic pole relatively close to said element and generally parallel to said elongated edge and generally uniformly spaced therefrom, and
Claim 5
Dependent Claim
40 words
A magnetic transducer head according to claim 3 with a width dimension of said element at right angles to the elongated edge of said element being about five micrometers and the thickness of said element being about five hundred angstroms.
Claim 6
Dependent Claim
51 words
A magnetic transducer head according to claim 3 with said elongated edge having a length of about sixty micrometers and said first elongated magnetic pole having a length at least equal to the length of said elongated edge and being essentially at least coextensive with the length of said elongated edge.
Claim 7
Dependent Claim
28 words
A magnetic transducer head according to claim 5 with a width dimension of said element at right angles to the longitudinal direction being at least about five micrometers.
Claim 8
Dependent Claim
180 words
A magnetic transducer head utilizing magneto resistance effect, comprising: a thin film magneto resistance effect element having an elongated edge arranged to closely confront a record track of a magnetic recording medium for scanning coupling with a signal recorded on the record track, said elongated edge being elongated transverse to a scanning direction along the record track, current supplying means connected with said element to produce a current flow in said element, biasing means coupled with said element to apply a D.C. bias magnetic field to said element, and means comprising the disposition of said elongated edge relative to said biasing means such that a demagnetizing field is produced which is relatively intense in a first region of said element at said elongated edge and is relatively less intense in a second region of said element remote from said elongated edge, with said D.C. bias magnetic field being of a strength to saturate said element at the second region thereof while the first region remains sensitive to a signal magnetic field from said record track of the magnetic recording medium.
Claim 9
Dependent Claim
180 words
A magnetic transducer head utilizing magneto resistance effect, comprising: a thin film magneto resistance effect element having an elongated edge arranged to closely confront a record track of a magnetic recording medium for scanning coupling with a signal recorded on the record track, said elongated edge being elongated transverse to a scanning direction along the record track, current supplying means connected with said element to produce a current flow in said element, biasing means coupled with said element to apply a D.C. bias magnetic field to said element, and means comprising the disposition of said elongated edge relative to said biasing means such that a demagnetizing field is produced which is relatively intense in a first region of said element at said elongated edge and is relatively less intense in a second region of said element remote from said elongated edge, with said D.C. bias magnetic field being of a strength to saturate said element at the second region thereof while the first region remains sensitive to a signal magnetic field from said record track of the magnetic recording medium.
Claim 10
Dependent Claim
38 words
A magnetic transducer head according to claim 7, with said element having a thickness not greater than about five hundred angstroms and a width dimension at right angles to said elongated edge of at least about five micrometers.
Claim 11
Dependent Claim
46 words
A magnetic transducer head according to claim 7 with said biasing means having a first elongated magnetic pole relatively close to said element and generally parallel to said elongated edge and generally uniformly spaced therefrom, and having a second magnetic pole relatively remote from said element.
Claim 12
Dependent Claim
28 words
A magnetic transducer head according to claim 9 with a width dimension of said element at right angles to the elongated edge being at least about five micrometers.
Claim 13
Dependent Claim
19 words
A magnetic transducer head according to claim 10, with said element having a thickness of about five hundred angstroms.
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) | 1988-06-17 | 1988-12-17 | 1989-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-17 | 1992-12-17 | 1993-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-17 | 1996-12-17 | 1997-06-18 | $7700.00 | Window Closed / Lapsed |