US5255141A
Expired / Lapsed
US
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Read-write magnetic head with flux sensing read element
Assignee: Western Digital Technologies Inc
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Filing: 1991-12-16
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Granted: 1993-10-19
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Expires: 2011-12-16
Abstract
Abstract A thin film read-write magnetic head includes a write inductive section having a magnetic circuit consisting of thin film magnetic layers and a read flux sensing element, such as a magnetoresistive device or Hall effect device, located in a gap in the magnetic circuit. During the write mode, a magnetic valve including an electrical conductor provides a shunt path to bypass the flux sensing element. During the read mode, a saturation current is directed to the valve conductor so that the shunt path is open, thereby allowing the flux sensing element to sense the readout signal.
Inventors
- 👤 Erich P. Valstyn
- 👤 Daniel A. Nepela
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 14:35
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; G11B5/3906; G11B5/3916; G11B5/3919; G11B5/3922; G11B5/3925; G11B5/332; G11B5/37
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
122 words
A thin film read-write magnetic head comprising: first and second magnetic layers for forming a magnetic circuit path with a transducing gap; flux sensing means disposed within said magnetic circuit path, said sensing means being bypassed and inactive during signal recording; magnetic valve means coupled to said magnetic circuit path for providing a magnetic shunt to bypass said flux sensing means during signal recording, said valve means comprising a magnetic shunt coupled to at least one of said magnetic layers and electrical conductor means encompassed by said magnetic, said magnetic valve means being deactivated by passing a current through said electrical conductor means during signal reading so that the flux representing a read out signal is sensed by said flux sensing means.
Claim 2
Dependent Claim
122 words
A thin film read-write magnetic head comprising: first and second magnetic layers for forming a magnetic circuit path with a transducing gap; flux sensing means disposed within said magnetic circuit path, said sensing means being bypassed and inactive during signal recording; magnetic valve means coupled to said magnetic circuit path for providing a magnetic shunt to bypass said flux sensing means during signal recording, said valve means comprising a magnetic shunt coupled to at least one of said magnetic layers and electrical conductor means encompassed by said magnetic, said magnetic valve means being deactivated by passing a current through said electrical conductor means during signal reading so that the flux representing a read out signal is sensed by said flux sensing means.
Claim 3
Dependent Claim
24 words
A magnetic head as in claim 1, wherein said second layer is formed with a separation in which said flux sensing means is located.
Claim 4
Dependent Claim
37 words
A magnetic head as in claim 2, wherein said second layer is formed with two portions around said separation, and said magnetic shunt comprises third and fourth magnetic layers disposed over said separation and over said portions.
Claim 5
Dependent Claim
28 words
A magnetic head as in claim 3, wherein said valve conductor means is disposed between said third and fourth magnetic layers for activating or deactivating said magnetic shunt.
Claim 6
Dependent Claim
30 words
A magnetic head as in claim 3, wherein the total thickness of said third and fourth magnetic layers is approximately the same as the thickness of said second magnetic layer.
Claim 7
Dependent Claim
27 words
A magnetic head as in claim 1, including an electrical coil disposed between said first and second magnetic layers for conducting electrical signals during the record mode.
Claim 8
Dependent Claim
17 words
A magnetic head as in claim 1, wherein said flux sensing means is a magnetoresistive sensing element.
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) | 1996-10-18 | 1997-04-19 | 1997-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-10-18 | 2001-04-19 | 2001-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-10-18 | 2005-04-19 | 2005-10-19 | $7700.00 | Window Closed / Lapsed |