Patent US5010429A successfully refreshed from Google Patents.
US5010429A
Expired / Lapsed
US
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Floating magnetic head having improved static friction coefficient
Assignee: Proterial Ltd
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Filing: 1989-06-01
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Granted: 1991-04-23
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Expires: 2009-06-01
Abstract
Abstract A floating type magnetic head is made of a polycrystalline material. A surface to be opposed to a magnetic recording medium is undulated with lands and grooves having a height different of 50 to 200 Å on an average and a repetition pitch of 5 to 20 microns on an average. The portions, in which the heights of the lands and the grooves abruptly change, extend along the boundaries of the polycrystals. The head surface opposed to the magnetic recording medium is sputter-etched to have the predetermined surface roughness.
Inventors
- 👤 Akira Taguchi
- 👤 Shigetoshi Morita
- 👤 Shunichi Taka
- 👤 Hirohide Yamada
- 👤 Yoshiaki Takada
- 👤 Shinji Furuichi
- 👤 Masahiro Ao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:44
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/187; G11B5/1871; G11B5/10; G11B5/48; G11B5/58; G11B5/60; G11B5/6005
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
61 words
A magnetic head comprising: a slider made of a polycrystalline ceramic material; and a magnetic core, said slider having a surface to be opposed to a magnetic disk, said opposed surface being formed of lands and grooves having a height difference of 50 to 200 A on an average and a repetition pitch of 5 to 20 microns on an average.
Claim 2
Dependent Claim
61 words
A magnetic head comprising: a slider made of a polycrystalline ceramic material; and a magnetic core, said slider having a surface to be opposed to a magnetic disk, said opposed surface being formed of lands and grooves having a height difference of 50 to 200 A on an average and a repetition pitch of 5 to 20 microns on an average.
Claim 3
Dependent Claim
35 words
A magnetic head according to claim 1, wherein said opposed surface is so undulated that portions having abrupt changes in the heights between said lands and said grooves extend along the boundaries of the polycrystals.
Claim 4
Dependent Claim
19 words
A magnetic head according to claim 1, wherein said lands have flat crests and said grooves have flat bottoms.
Claim 5
Dependent Claim
36 words
A magnetic head according to claim 1, wherein at least one portion of said opposed surface is finished to have a height difference of 50 to 300 A of undulations of said lands and said grooves.
Claim 6
Dependent Claim
18 words
A magnetic head according to claim 1, wherein the ceramic material composing said slider is spinel type ferrite.
Claim 7
Dependent Claim
20 words
A magnetic head according to claim 1, wherein the ceramic material composing said slider is Mn-Zn ferrite or Ni-Zn ferrite.
Claim 8
Dependent Claim
18 words
A magnetic head according to claim 1, wherein the ceramic material composing said slider is an Mn-Ni oxide.
Claim 9
Dependent Claim
23 words
A magnetic head according to claim 1, wherein the ceramic material composing said slider is calcium titanate, barium titanate, alumina or zinc ferrite.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-04-22 | 1994-10-22 | 1995-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-04-22 | 1998-10-22 | 1999-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-04-22 | 2002-10-22 | 2003-04-23 | $7700.00 | Window Closed / Lapsed |