Patent US4663684A successfully refreshed from Google Patents.
US4663684A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic transducer using magnetoresistance effect
Assignee: Hitachi Ltd
•
Filing: 1985-01-25
•
Granted: 1987-05-05
•
Expires: 2005-01-25
Abstract
Abstract Disclosed is a magnetic transducer using a magnetoresistance effect, comprising a magnetoresistive film, a hard magnetic film for applying a transverse biasing magnetic field thereto, and a conductive film through which current for applying the transverse biasing magnetic field to the magnetoresistive film flows. The conductive film may be either in electrical contact with or in electrical insulation from the magnetoresistive film. In this magnetic transducer, even when the heights of the respective constituents have changed, the transverse biasing magnetic field to be applied does not change considerably, and an optimum bias field strength is readily attained.
Inventors
- 👤 Yoshihisa Kamo
- 👤 Naoki Sato
- 👤 Masahiro Kitada
- 👤 Tooru Takeura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:53
CPC Classifications
B; B82; B82Y; B82Y25/00; G; G01; G01R; G01R33/00; G01R33/02; G01R33/06; G01R33/09; G01R33/093; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; G11B5/3906; G11B5/3929; G11B5/3932; G11B5/399
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
141 words
A magnetic transducer using a magnetoresistance effect comprising (i) a magnetoresistive film, (ii) a hard magnetic film being arranged relative to said magnetoresistive film so as to apply a transverse biasing magnetic field to said magnetoresistive film, which hard magnetic film is magnetized in a direction approximately perpendicular to a surface facing a recording medium and which is disposed on said magnetoresistive film through an insulating film, and (iii) at least one conductive film which is stacked on said magnetoresistive film, the magnetic fields generated by the hard magnetic film and by causing a current to flow through the conductive film being complementary to each other with respect to changes in the heights of the films so as to suppress rate of change in the transverse biasing magnetic field relative to the rate of change of the heights of the films.
Claim 2
Dependent Claim
141 words
A magnetic transducer using a magnetoresistance effect comprising (i) a magnetoresistive film, (ii) a hard magnetic film being arranged relative to said magnetoresistive film so as to apply a transverse biasing magnetic field to said magnetoresistive film, which hard magnetic film is magnetized in a direction approximately perpendicular to a surface facing a recording medium and which is disposed on said magnetoresistive film through an insulating film, and (iii) at least one conductive film which is stacked on said magnetoresistive film, the magnetic fields generated by the hard magnetic film and by causing a current to flow through the conductive film being complementary to each other with respect to changes in the heights of the films so as to suppress rate of change in the transverse biasing magnetic field relative to the rate of change of the heights of the films.
Claim 3
Dependent Claim
37 words
A magnetic transducer using a magnetoresistance effect as defined in claim 1, wherein said magnetoresistive film, said hard magnetic film and said conductive film are sandwiched between shielding soft magnetic members which are disposed through insulating films.
Claim 4
Dependent Claim
29 words
A magnetic transducer using a magnetoresistance effect as defined in claim 1, wherein said at least one conductive film is stacked on said magnetoresistive film in electrical contact therewith.
Claim 5
Dependent Claim
37 words
A magnetic transducer using a magnetoresistance effect as defined in claim 3, wherein the at least one conductive film is a plurality of conductive films, the conductive films being disposed on both sides of said magnetoresistive film.
Claim 6
Dependent Claim
37 words
A magnetic transducer using a magnetoresistance effect as defined in claim 4, wherein said magnetoresistive film, said hard magnetic film and said conductive film are sandwiched between shielding soft magnetic members which are disposed through insulating films.
Claim 7
Dependent Claim
21 words
A magnetic transducer using a magnetoresistance effect as defined in claim 5, wherein said soft magnetic members are soft magnetic films.
Claim 8
Dependent Claim
24 words
A magnetic transducer using a magnetoresistance effect as defined in claim 5, wherein one of said soft magnetic members serves also as a substrate.
Claim 9
Dependent Claim
37 words
A magnetic transducer using a magnetoresistance effect as defined in claim 3, wherein said magnetoresistive film, said hard magnetic film and said conductive film are sandwiched between shielding soft magnetic members which are disposed through insulating films.
Claim 10
Dependent Claim
21 words
A magnetic transducer using a magnetoresistance effect as defined in claim 8, wherein said soft magnetic members are soft magnetic films.
Claim 11
Dependent Claim
24 words
A magnetic transducer using a magnetoresistance effect as defined in claim 8, wherein one of said soft magnetic members serves also as a substrate.
Claim 12
Dependent Claim
29 words
A magnetic transducer using a magnetoresistance effect as defined in claim 1, wherein said at least one conductive film is stacked on said magnetoresistive film through an insulating layer.
Claim 13
Dependent Claim
45 words
A magnetic transducer using a magnetoresistance effect as defined in claim 11, comprising both the conductive film which is stacked on said magnetoresistive film through said insulating layer and the conductive film which is stacked on said magnetoresistive film in close and electrical contact therewith.
Claim 14
Dependent Claim
37 words
A magnetic transducer using a magnetoresistance effect as defined in claim 12, wherein said magnetoresistive film, said hard magnetic film and said conductive films are sandwiched between shielding soft magnetic members which are disposed through insulating films.
Claim 15
Dependent Claim
24 words
A magnetic transducer using a magnetoresistance effect as defined in claim 13, wherein one of said soft magnetic members serves also as a substrate.
Claim 16
Dependent Claim
37 words
A magnetic transducer using a magnetoresistance effect as defined in claim 11, wherein said magnetoresistive film, said hard magnetic film and said conductive film are sandwiched between shielding soft magnetic members which are disposed through insulating films.
Claim 17
Dependent Claim
21 words
A magnetic transducer using a magnetoresistance effect as defined in claim 15, wherein said soft magnetic members are soft magnetic films.
Claim 18
Dependent Claim
21 words
A magnetic transducer using a magnetoresistance effect as defined in claim 13, wherein said soft magnetic members are soft magnetic films.
Claim 19
Dependent Claim
24 words
A magnetic transducer using a magnetoresistance effect as defined in claim 15, wherein one of said soft magnetic members serves also as a substrate.
Claim 20
Dependent Claim
24 words
A magnetic transducer using a magnetoresistance effect as defined in claim 1, wherein the hard magnetic film has a thickness of 100 Å-3000 Å.
Claim 21
Dependent Claim
33 words
A magnetic transducer using a magnetoresistance effect as defined in claim 1, wherein the conductive film is made of a material selected from the group consisting of Mo, Ti, Au, Ta or Nb.
Claim 22
Dependent Claim
24 words
A magnetic transducer using a magnetoresistance effect as defined in claim 1, wherein the conductive film has a thickness of at least 150 Å.
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) | 1990-05-04 | 1990-11-03 | 1991-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-04 | 1994-11-03 | 1995-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-04 | 1998-11-03 | 1999-05-05 | $7700.00 | Window Closed / Lapsed |