EP0081240A2
Expired / Lapsed
EP
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Thin film magnetic head
Assignee: Panasonic Holdings Corp
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Filing: 1982-12-08
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Granted: —
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Expires: 2002-12-08
Abstract
Abstract A magnetoresistive type thin film magnetic head is completely unaffected by external noise and produces only low interference with a recording medium. A magnetoresistive element which constitutes the thin film magnetic head has three terminals constituted by two end terminals and an intermediate terminal. Constant currents which flow in the opposite directions are respectively supplied to the two end terminals. A magnetic field of a signal recorded on and reproduced from a single track of the recording medium is applied to the magnetoresistive element, and reproduction outputs of opposite phases appear at the two end terminals. These outputs are differentially amplified by a differential amplifier. Furthermore, the magnetoresistive element is biased by an induced magnetic anisotropy means in a predetermined direction.
Inventors
- 👤 Noboru Nomura
- 👤 Yasuharu Shimeki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 20:01
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; G11B5/3906; G11B5/3945; G11B5/3948; G11B5/3958; G11B5/3961; G11B5/3964; G11B5/399
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
135 words
A thin film magnetic head having a magnetoresistive element in which a thin ferromagnetic film is deposited on a substrate, wherein said magnetoresistive element has three terminals constituted by two end terminals and an intermediate terminal and is biased to be magnetized in one direction; a change in resistance of a first portion between one of-said two end terminals and said intermediate terminal and a chance in resistance of a second portion between the other of said two end terminals and said intermediate terminal which are obtained by applying a magnetic field of a signal recorded on and reproduced from a single track of a magnetic recording medium are respectively obtained as reproduction voltages by flowing a current through said first and second portions in the same direction; and the reproduction voltages are differentially amplified.
Claim 2
Dependent Claim
135 words
A thin film magnetic head having a magnetoresistive element in which a thin ferromagnetic film is deposited on a substrate, wherein said magnetoresistive element has three terminals constituted by two end terminals and an intermediate terminal and is biased to be magnetized in one direction; a change in resistance of a first portion between one of-said two end terminals and said intermediate terminal and a chance in resistance of a second portion between the other of said two end terminals and said intermediate terminal which are obtained by applying a magnetic field of a signal recorded on and reproduced from a single track of a magnetic recording medium are respectively obtained as reproduction voltages by flowing a current through said first and second portions in the same direction; and the reproduction voltages are differentially amplified.
Claim 3
Dependent Claim
27 words
A head according to claim 1, wherein said head is biased to be magnetized in said one direction by induced magnetic anisotropy produced in said magnetoresistive element.
Claim 4
Dependent Claim
28 words
A head according to claim 2, wherein said induced magnetic anisotropy is produced by a linear indentation pattern formed on at least one surface of said magnetoresistive element.
Claim 5
Dependent Claim
35 words
A head according to claim 2, wherein said induced magnetic anisotropy is produced by an anisotropic characteristic of a thermal expansion coefficient of said substrate and by magnetostriction incurred in said magnetoresistive element formed thereon.
Claim 6
Dependent Claim
143 words
A thin film magnetic head having a magnetoresistive element in which a thin ferromagnetic film is deposited on a substrate, wherein said magnetoresistive element has three terminals constituted by two end terminals and an intermediate terminal which is grounded in an AC manner, and is biased to be magnetized in one direction; a change in resistance of a first portion between one of said two end terminals and said intermediate terminal and a change in resistance of a second portion between the other of said two end terminals and said intermediate terminal which are obtained by applying a magnetic field of a signal recorded on and reproduced from a single track of a magnetic recording medium are respectively obtained as reproduction voltages by flowing a current through said first and second portions in the same direction; and the reproduction voltages are differentially amplified.
Claim 7
Dependent Claim
143 words
A thin film magnetic head having a magnetoresistive element in which a thin ferromagnetic film is deposited on a substrate, wherein said magnetoresistive element has three terminals constituted by two end terminals and an intermediate terminal which is grounded in an AC manner, and is biased to be magnetized in one direction; a change in resistance of a first portion between one of said two end terminals and said intermediate terminal and a change in resistance of a second portion between the other of said two end terminals and said intermediate terminal which are obtained by applying a magnetic field of a signal recorded on and reproduced from a single track of a magnetic recording medium are respectively obtained as reproduction voltages by flowing a current through said first and second portions in the same direction; and the reproduction voltages are differentially amplified.
Claim 8
Dependent Claim
35 words
A head according to claim 5, wherein the one of said two end terminals formed at said magnetoresistive element is grounded through a resistor, whereas the other of said two end terminals receives a current.
References Cited (Backward Citations)
No citation records indexed.
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