US4969253A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing a magnetic head
Assignee: Pioneer Corp
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Filing: 1990-02-09
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Granted: 1990-11-13
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Expires: 2010-02-09
Abstract
Abstract A magnetic recording playback head and a method for producing the same having an improved wear resistance and resistance to chipping as well as an improved production rate. The head is formed from a pair of magnetic cores joined through a gap-forming film. The lateral sides of the gap are flat, except for the surface repair to contact the tape, which have a width equal to the track width. The flat sides are coated with a nonmagnetic thin hard film of a material such as alumina or titanium nitride.
Inventors
- 👤 Hiroyuki Ota
- 👤 Kazuhiko Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:49
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/187; G11B5/255; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49036; Y10T29/49041; Y10T29/49048; Y10T29/49055; Y10T29/49057
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
219 words
A method for fabricating a magnetic head, the magnetic head including a sliding surface for contacting a magnetic tape, the magnetic head having a track width which is substantially the same as a width of the sliding surface, comprising the steps of: providing two half blocks of a magnetic oxide material; joining said two half blocks to form a single core block with a gap-forming thin film on respective gap-forming surfaces of said half blocks; grinding and polishing said core block to form a cylindrical surface to be in sliding contact with the magnetic tape; cutting a plurality of track width defining grooves in said cylindrical surface leaving a plurality of ridges each having flat lateral sides and width equal to a track width to thereby form a head block; forming a thin film of a hard nonmagnetic material on said cylindrical surface of each of said ridges and in said track width defining grooves which include said flat lateral sides of said ridges; grinding and polishing said head block to remove said thin film from said cylindrical surface of each of said ridges but not from said grooves which include said flat lateral sides of each of said ridges; and slicing said head block along a center line of each of said grooves to form discrete magnetic heads.
Claim 2
Independent Claim
219 words
A method for fabricating a magnetic head, the magnetic head including a sliding surface for contacting a magnetic tape, the magnetic head having a track width which is substantially the same as a width of the sliding surface, comprising the steps of: providing two half blocks of a magnetic oxide material; joining said two half blocks to form a single core block with a gap-forming thin film on respective gap-forming surfaces of said half blocks; grinding and polishing said core block to form a cylindrical surface to be in sliding contact with the magnetic tape; cutting a plurality of track width defining grooves in said cylindrical surface leaving a plurality of ridges each having flat lateral sides and width equal to a track width to thereby form a head block; forming a thin film of a hard nonmagnetic material on said cylindrical surface of each of said ridges and in said track width defining grooves which include said flat lateral sides of said ridges; grinding and polishing said head block to remove said thin film from said cylindrical surface of each of said ridges but not from said grooves which include said flat lateral sides of each of said ridges; and slicing said head block along a center line of each of said grooves to form discrete magnetic heads.
Claim 3
Dependent Claim
24 words
The method of claim 1, wherein said thin film is formed of a material selected from the group consisting of alumina and titanium oxide.
Claim 4
Dependent Claim
20 words
The method of claim 2, wherein said step of forming said thin film is carried out using an evaporation process.
Claim 5
Dependent Claim
21 words
The method of claim 2, wherein said step of forming said thin film is carried out using an ion plating process.
Claim 6
Dependent Claim
21 words
The method of claim 2, wherein said step of forming said thin film is carried out using an ion plating process.
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) | 1993-11-12 | 1994-05-14 | 1994-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-12 | 1998-05-14 | 1998-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-12 | 2002-05-14 | 2002-11-13 | $7700.00 | Window Closed / Lapsed |