US4179719A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thin film magnetic head
Assignee: KDDI Corp
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Filing: 1977-01-25
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Granted: 1979-12-18
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Expires: 1997-01-25
Abstract
Abstract A magnetic head for reading out the state of magnetization recorded on a magnetic recording medium, in which the magnetic head comprises a substrate of insulating material, an amorphous magnetic thin film, a pair of current terminals, and a pair of voltage terminals. The amorphous magnetic thin film is deposited on the substrate so as to have a width smaller than respective unit areas of magnetic records on a magnetic recording medium to be separately read out therefrom and to have an easy axis of magnetization in a direction perpendicular to the film surface. The current terminals are formed on the substrate for flowing a current in the amorphous magnetic thin film in the lengthwise direction thereof. The voltage terminals are formed on the substrate for deriving from the amorphous magnetic thin film a voltage induced in the transverse direction thereof.
Inventors
- 👤 Nobutake Imamura
- 👤 Yoshinori Mimura
- 👤 Toshihiko Kobayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:53
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/49; G11B5/4907; G01; G01R; G01R33/00; G01R33/02; G01R33/06; G01R33/07; G11B5/127; G11B5/33; G11B5/332; G11B5/37; G11B5/372
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
113 words
A thin film magnetic head comprising: a substrate of insulating material; an amorphous magnetic thin film deposited on the substrate, the amorphous magnetic thin film having a width smaller than each of unit areas of magnetic records on a magnetic recording medium to be separately read out therefrom and having an easy axis of manetization in a direction perpendicular to the film surface; a pair of current terminals formed on the substrate for flowing a current in the amorphous magnetic thin film in the lengthwise direction thereof; and a pair of voltage terminals formed on the substrate for deriving from the amorphous magnetic thin film a voltage induced in the transverse direction thereof.
Claim 2
Dependent Claim
113 words
A thin film magnetic head comprising: a substrate of insulating material; an amorphous magnetic thin film deposited on the substrate, the amorphous magnetic thin film having a width smaller than each of unit areas of magnetic records on a magnetic recording medium to be separately read out therefrom and having an easy axis of manetization in a direction perpendicular to the film surface; a pair of current terminals formed on the substrate for flowing a current in the amorphous magnetic thin film in the lengthwise direction thereof; and a pair of voltage terminals formed on the substrate for deriving from the amorphous magnetic thin film a voltage induced in the transverse direction thereof.
Claim 3
Dependent Claim
23 words
A thin film magnetic head according to claim 1, wherein the amorphous magnetic thin film is formed in the shape of a strip.
Claim 4
Dependent Claim
23 words
A thin film magnetic head according to claim 1, wherein the amorphous magnetic thin film is formed in the shape of a cross.
Claim 5
Dependent Claim
21 words
A thin film magnetic head according to claim 1, wherein the amorphous magnetic thin film is formed in a rhombic shape.
Claim 6
Dependent Claim
19 words
A thin film magnetic head according to claim 1, wherein the amorphous magnetic thin film is a multi-layer one.
Claim 7
Dependent Claim
51 words
A thin film magnetic head according to claim 5, wherein the amorphous magnetic thin film is composed of a first layer having a large coercive force and a thickness of less than 2000 A, and a second layer having a small coercive force and a thickness of 1000 to 10000 A.
Claim 8
Dependent Claim
57 words
In a thin film magnetic head: a substrate of electrically insulative material; a first amorphous magnetic thin film disposed on a surface of said substrate; and a second amorphous magnetic thin film disposed on said first amorphous magnetic thin film, wherein said first and said second amorphous magnetic thin films have respective coercive forces of different values.
Claim 9
Dependent Claim
57 words
In a thin film magnetic head: a substrate of electrically insulative material; a first amorphous magnetic thin film disposed on a surface of said substrate; and a second amorphous magnetic thin film disposed on said first amorphous magnetic thin film, wherein said first and said second amorphous magnetic thin films have respective coercive forces of different values.
Claim 10
Dependent Claim
56 words
In a thin film magnetic head according to claim 7: wherein said first amorphous magnetic thin film has a large coercive force and has a thickness less than about 2000 A; and wherein said second amorphous magnetic thin film has a small coercive force and has a thickness between about 1,000 A and about 10,000 A.
References Cited (Backward Citations)
US3260980A
Cited
US3200207A
Cited
US3425047A
Cited
US3389230A
Cited
US3643035A
Cited
US4079430A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-12-17 | 1983-06-18 | 1983-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-17 | 1987-06-18 | 1987-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-17 | 1991-06-18 | 1991-12-18 | $7700.00 | Window Closed / Lapsed |