Patent US4814918A successfully refreshed from Google Patents.
US4814918A
Expired / Lapsed
US
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Multitrack magnetic head having magnetically coupled transducer elements
Assignee: US Philips Corp
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Filing: 1987-05-28
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Granted: 1989-03-21
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Expires: 2007-05-28
Abstract
Abstract Elongate magneto-resistive elements (3) spaced apart on a substrate (9) incorporated in a magnetic circuit constituted by a magnetic yoke (5, 7, 9) which is provided with pole faces (19, 21) for the purpose of co-operating with the registration medium, while each magneto-resistive element is provided with two contacts (3A) for connection to a measuring current source. To improve the stability of the magneto-resistive elements, the magnetic head has strip-shaped coupling elements (17) which magnetically couple the magneto-resistive elements and keep them electrically separated from each other.
Inventors
- 👤 Gerardus H. J. Somers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:12
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; G11B5/3906; G11B5/3929; G11B5/3935; G11B5/3945; G11B5/3948; G11B5/3958; G11B5/3961; G11B5/398
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
160 words
A magnetic head for detecting magnetic fields representing information on a magnetic registration medium which is relatively movable with respect to the magnetic head, comprising a substrate on which a number of juxtaposed elongated magneto-resistive elements are provided which are each incorporated in a magnetic circuit constituted by a magnetic yoke which is provided with pole faces for the purpose of co-operating with the registration medium, each magneto-resistive element having two oppositely located edge portions provided with contacts for connection to a measuring current source, characterized in that the magnetic head is provided with strip-shaped coupling elements of a magnetically permeable material for coupling the magneto-resistive elements in a soft magnetic manner, each coupling element bridging the distance between two adjacent magneto-resistive elements and covering the edge portions facing each other, the head being further provided with means for electrically separating the coupling elements from the magneto-resistive elements, whereby the magneto-resistive elements exhibit good magnetic coupling while being electrically decoupled.
Claim 2
Dependent Claim
160 words
A magnetic head for detecting magnetic fields representing information on a magnetic registration medium which is relatively movable with respect to the magnetic head, comprising a substrate on which a number of juxtaposed elongated magneto-resistive elements are provided which are each incorporated in a magnetic circuit constituted by a magnetic yoke which is provided with pole faces for the purpose of co-operating with the registration medium, each magneto-resistive element having two oppositely located edge portions provided with contacts for connection to a measuring current source, characterized in that the magnetic head is provided with strip-shaped coupling elements of a magnetically permeable material for coupling the magneto-resistive elements in a soft magnetic manner, each coupling element bridging the distance between two adjacent magneto-resistive elements and covering the edge portions facing each other, the head being further provided with means for electrically separating the coupling elements from the magneto-resistive elements, whereby the magneto-resistive elements exhibit good magnetic coupling while being electrically decoupled.
Claim 3
Dependent Claim
22 words
A magnetic head as claimed in claim 1, characterized in that the coupling elements are provided with extremities which are rounded off.
Claim 4
Dependent Claim
49 words
A magnetic head as claimed in claim 2, characterized in that means for electrically separating the coupling elements from the magneto-resistive elements comprises insulation layers of an electrically insulating material, which layers are provided at the area of the edge portions between the magneto-resistive elements and the coupling elements.
Claim 5
Dependent Claim
49 words
A magnetic head as claimed in claim 1, characterized in that means for electrically separating the coupling elements from the magneto-resistive elements comprises insulation layers of an electrically insulating material, which layers are provided at the area of the edge portions between the magneto-resistive elements and the coupling elements.
Claim 6
Dependent Claim
41 words
A magnetic head as claimed in claim 4 in which the magnetic head is manufactured by means of a thin-film technique, characterized in that the coupling elements are formed from an Ni-Fe-based alloy and the insulation layers are formed from quartz.
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) | 1992-03-20 | 1992-09-19 | 1993-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-20 | 1996-09-19 | 1997-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-20 | 2000-09-19 | 2001-03-21 | $7700.00 | Window Closed / Lapsed |