US4682256A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing a composite type magnetic head
Assignee: Victor Company of Japan Ltd
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Filing: 1985-10-28
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Granted: 1987-07-21
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Expires: 2005-10-28
Abstract
Abstract A composite type magnetic head comprises first and second magnetic head core halves made of a magnetic ferrite, a gap member interposed between the first and second magnetic head core halves, a first narrowed part which is formed on the first magnetic head core half and is narrowed toward the gap member by being defined by first and second curved depressions, a second narrowed part which is formed on the second magnetic head core half and is narrowed toward the gap member by being defined by third and fourth curved depressions, a first film made of a magnetic metal material formed on a surface of the first curved depression, and a second film made of the magnetic metal material formed on a surface of the third curved depression. The first and second films have film thicknesses equal to a desired track width at a part where the first and second films make contact with the gap member and form a gap of the magnetic head.
Inventors
- 👤 Yasuhiro Ayabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 00:54
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/187; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49036; Y10T29/49043; Y10T29/49048; Y10T29/49055; Y10T29/49067
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
325 words
A method of manufacturing a composite type magnetic head having a contact surface for scanning a magnetic recording medium, said method comprising: a step of forming, with a predetermined interval, first curved depressions on a first block half made of a magnetic ferrite and second curved depressions on a second block half made of the magnetic ferrite; a step of forming a first film made of a magnetic metal material directly on at least a portion of each surface of the first curved depressions and a second film also made of said magnetic metal material directly on at least a portion of each surface of the second curved depressions; a step of filling a glass sealing in the first and second curved depressions on top of the first and second films; a step of lapping gap surfaces of the first and second block halves, said first and second films respectively having film thicknesses equal to a desired track width at said gap surfaces of the first and second block halves; a step of forming third curved depressions on the first block half adjacent to the first curved depressions so that the first film is exposed for a predetermined range in a vicinity of the gap surface and fourth curved depressions on the second block half adjacent to the second curved depressions so that the second film is exposed for the predetermined range in a vicinity of the gap surface; a step of forming a block by binding the first and second block halves together with a gap member interposed between the gap surfaces so that the film thicknesses of the first and second films coincide with each other to form a gap of the magnetic head at the contact surface, said first and second films constituting a generally S-shaped contour at the contact surface which includes said gap of the magnetic head; and a step of slicing the block into a plurality of magnetic heads.
Claim 2
Independent Claim
325 words
A method of manufacturing a composite type magnetic head having a contact surface for scanning a magnetic recording medium, said method comprising: a step of forming, with a predetermined interval, first curved depressions on a first block half made of a magnetic ferrite and second curved depressions on a second block half made of the magnetic ferrite; a step of forming a first film made of a magnetic metal material directly on at least a portion of each surface of the first curved depressions and a second film also made of said magnetic metal material directly on at least a portion of each surface of the second curved depressions; a step of filling a glass sealing in the first and second curved depressions on top of the first and second films; a step of lapping gap surfaces of the first and second block halves, said first and second films respectively having film thicknesses equal to a desired track width at said gap surfaces of the first and second block halves; a step of forming third curved depressions on the first block half adjacent to the first curved depressions so that the first film is exposed for a predetermined range in a vicinity of the gap surface and fourth curved depressions on the second block half adjacent to the second curved depressions so that the second film is exposed for the predetermined range in a vicinity of the gap surface; a step of forming a block by binding the first and second block halves together with a gap member interposed between the gap surfaces so that the film thicknesses of the first and second films coincide with each other to form a gap of the magnetic head at the contact surface, said first and second films constituting a generally S-shaped contour at the contact surface which includes said gap of the magnetic head; and a step of slicing the block into a plurality of magnetic heads.
Claim 3
Dependent Claim
28 words
A method as claimed in claim 1 in which said step of forming the first and second films forms the first and second films by a sputtering process.
Claim 4
Dependent Claim
34 words
A method as claimed in claim 2 in which said step of forming the first and second films forms the first and second films by a process of sputtering an alloy in Fe-Si-Al system.
Claim 5
Dependent Claim
54 words
A method as claimed in claim 2 in which said step of forming the first and second films forms the first and second films over approximately half the respective surfaces of the first and second curved depressions by a process of sputtering the magnetic metal material in an oblique direction to the gap surfaces.
Claim 6
Dependent Claim
64 words
A method as claimed in claim 1 in which said step of forming the third and fourth curved depressions chips the first and second films for said predetermined range in the film thickness direction so that the film thicknesses of the first and second films are equal to the desired track width at the part where the gap of the magnetic head is formed.
Claim 7
Dependent Claim
48 words
A method as claimed in claim 1 which further comprises before said step of slicing the block a step of filling a glass sealing in said third and fourth curved depressions and a step of lapping said contact surface which makes sliding contact with a magnetic recording medium.
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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) | 1990-07-20 | 1991-01-19 | 1991-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-20 | 1995-01-19 | 1995-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-20 | 1999-01-19 | 1999-07-21 | $7700.00 | Window Closed / Lapsed |