US4399479A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thin film magnetic head having good low frequency response
Assignee: Eastman Kodak Co
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Filing: 1981-02-04
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Granted: 1983-08-16
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Expires: 2001-02-04
Abstract
Abstract To provide a thin film magnetic head having good low frequency response, the invention teaches the use of a movable mask technique whereby a first deposited magnetic film is provided with a tapered, or knife-, edge. Gap spacer material is then deposited on the film knife-edge. Thereafter, a second magnetic film is deposited atop the knife-edge, as well as on the same substrate that supports the first magnetic film. What results, therefore, is a slant gap thin film magnetic head having good low frequency response.
Inventors
- 👤 Benjamin B. Meckel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:03
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/187; G11B5/23; G11B5/232; G11B5/31; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49036; Y10T29/49043; Y10T29/49044; Y10T29/49055
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
217 words
A structure useful in a thin film magnetic head having good low frequency response comprising (a) a non-magnetic support having a generally planar surface, (b) a first generally planar thin film of magnetic material deposited on a first part of said planar surface and having at least one tapered edge thereof, (c) a thin film of non-magnetic material deposited on both said tapered edge of said first thin film of magnetic material and over at least part of the planar surface thereof, and (d) a second generally planar thin film of magnetic material deposited on a second part of the surface of said non-magnetic support and upon said non-magnetic film on said tapered edge of said first thin film of magnetic material, said thin films of magnetic material constituting the poles of said magnetic head structure and said thin film of non-magnetic material defining a slanted transducer gap between said poles, part of said thin film of non-magnetic material being further deposited on said second part of the planar surface of said non-magnetic support so as to reside beneath said second thin film of magnetic material in proximity of said transducer gap, thereby to lessen the chance of inadvertent magnetic short circuiting of flux across said slanted transducer gap from one head structure pole to the other.
Claim 2
Dependent Claim
217 words
A structure useful in a thin film magnetic head having good low frequency response comprising (a) a non-magnetic support having a generally planar surface, (b) a first generally planar thin film of magnetic material deposited on a first part of said planar surface and having at least one tapered edge thereof, (c) a thin film of non-magnetic material deposited on both said tapered edge of said first thin film of magnetic material and over at least part of the planar surface thereof, and (d) a second generally planar thin film of magnetic material deposited on a second part of the surface of said non-magnetic support and upon said non-magnetic film on said tapered edge of said first thin film of magnetic material, said thin films of magnetic material constituting the poles of said magnetic head structure and said thin film of non-magnetic material defining a slanted transducer gap between said poles, part of said thin film of non-magnetic material being further deposited on said second part of the planar surface of said non-magnetic support so as to reside beneath said second thin film of magnetic material in proximity of said transducer gap, thereby to lessen the chance of inadvertent magnetic short circuiting of flux across said slanted transducer gap from one head structure pole to the other.
Claim 3
Dependent Claim
58 words
The structure of claim 1 including yoke means magnetically coupled (a) to said first thin film of magnetic material at a location thereof that is distant with respect to said slanted transducer gap, and (b) to said second thin film of magnetic material at a location thereof that is also distant with respect to said slanted transducer gap.
Claim 4
Dependent Claim
27 words
The magnetic head structure of claim 2 wherein said magnetic films are comprised of permalloy material and said film of non-magnetic material is comprised of silicon oxide.
References Cited (Backward Citations)
US2325844A
Cited
US2543483A
Cited
US2653189A
Cited
US2697754A
Cited
US2635149A
Cited
US2832839A
Cited
USRE29326E
Cited
JPS5274321A
Cited
US4219854A
Cited
US4219855A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-15 | 1987-02-14 | 1987-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-15 | 1991-02-14 | 1991-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-15 | 1995-02-14 | 1995-08-16 | $7700.00 | Window Closed / Lapsed |