US4458280A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Servo writing transducer design and writing method
Assignee: International Business Machines Corp
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Filing: 1982-01-18
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Granted: 1984-07-03
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Expires: 2002-01-18
Abstract
Abstract A servo writing transducer is shown having transverse side surfaces of the pole pieces adjoining the gap formed to optimize compression of the fringe field at one transverse side to reduce the dead band intermediate servo tracks. The existence of a wider fringe field region at the opposite transverse side is without consequence since the servo writing procedure is to first write the farthest track at the transducer side at which the compressed field occurs followed by each succeeding, adjoining servo track causing the information written in the wide fringe field to be overwritten by the next track.
Inventors
- 👤 Earl A. Cunningham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:33
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/012; G11B5/127; G11B5/31; G11B5/3109; G11B5/3116; G11B5/48; G11B5/58; G11B5/596; G11B5/59633
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
141 words
A servo write head for writing magnetic servo information on an associated magnetic media having adjoining, parallel servo track portions, said write head including spaced pole pieces defining a transducing gap wherein the gap length is the length of the space between the pole pieces at the transducing gap and the gap width is the distance between first and second transverse sides of the confronting pole piece portions that substantially defines the width of the magnetized track as the associated media is moved past the transducing gap, said first transverse side surface of said write head pole pieces forming an obtuse angle with said associated media, and said second transverse side surface of said write head pole pieces forming an acute angle with said associated media, whereby the width of the fringing field adjacent said first transverse side surface is minimized.
Claim 2
Dependent Claim
141 words
A servo write head for writing magnetic servo information on an associated magnetic media having adjoining, parallel servo track portions, said write head including spaced pole pieces defining a transducing gap wherein the gap length is the length of the space between the pole pieces at the transducing gap and the gap width is the distance between first and second transverse sides of the confronting pole piece portions that substantially defines the width of the magnetized track as the associated media is moved past the transducing gap, said first transverse side surface of said write head pole pieces forming an obtuse angle with said associated media, and said second transverse side surface of said write head pole pieces forming an acute angle with said associated media, whereby the width of the fringing field adjacent said first transverse side surface is minimized.
Claim 3
Dependent Claim
46 words
The servo write head of claim 1 wherein the width of the pole piece from said first side to said second side at the transducing gap is greater than or equal to the centerline to centerline distance between adjoining tracks of the media being servo written.
Claim 4
Dependent Claim
27 words
The servo write head of claim 1 wherein said first transverse pole piece side surfaces form an angle with the associated media of at least 120 degrees.
Claim 5
Dependent Claim
29 words
The servo write head of claim 1 wherein said second transverse pole piece side surfaces of said head form an angle with the associated media not exceeding 30 degrees.
Claim 6
Dependent Claim
22 words
The servo write head of claim 1 wherein said head is a thin film magnetic head assembly formed on a non-magnetic substrate.
Claim 7
Dependent Claim
46 words
The servo write head of claim 5 wherein said first transverse pole piece side surfaces form an angle with the associated media of at least 120 degrees and said second transverse pole piece side surfaces form an angle with the associated media not exceeding 30 degrees.
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) | 1987-07-03 | 1988-01-02 | 1988-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-03 | 1992-01-02 | 1992-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-03 | 1996-01-02 | 1996-07-03 | $7700.00 | Window Closed / Lapsed |