US4805048A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for controlling to keep off defects on magnetic disks
Assignee: Hitachi Ltd
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Filing: 1987-11-04
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Granted: 1989-02-14
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Expires: 2007-11-04
Abstract
Abstract A method for controlling to keep off defects in a magnetic disk apparatus while has a plurality of magnetic disks and defect position information is recorded in each of tracks on each magnetic disk to keep off a defect in writing records in each track. Positional information about defects on all the tracks belonging to a cylinder of the magnetic disk apparatus is recorded in each of the tracks, and records are written in each of the tracks while keeping off the defects on the basis of the recorded positional information about the defects.
Inventors
- 👤 Hisaharu Takeuchi
- 👤 Hisashi Takamatsu
- 👤 Masahiro Nakayama
- 👤 Yoshiro Shiroyanagi
- 👤 Akira Kurano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 07:58
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/18; G11B20/1883; G11B20/12; G11B20/1217; G11B20/1252; G11B2220/00; G11B2220/20; G11B2220/25; G11B2220/2508
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
101 words
A method for controlling to keep off defects usable in a magnetic disk apparatus, in which a plurality of magnetic disks are included and defect position information is recorded in each of tracks on each magnetic disk to keep off a defect in writing records in each track, said method comprising the steps of: recording the positional information about defects on all the tracks belonging to a cylinder of the magnetic disk apparatus, in each of the tracks; and writing records in each of the tracks, while keeping off said defects on the basis of the positional information about said defects.
Claim 2
Independent Claim
101 words
A method for controlling to keep off defects usable in a magnetic disk apparatus, in which a plurality of magnetic disks are included and defect position information is recorded in each of tracks on each magnetic disk to keep off a defect in writing records in each track, said method comprising the steps of: recording the positional information about defects on all the tracks belonging to a cylinder of the magnetic disk apparatus, in each of the tracks; and writing records in each of the tracks, while keeping off said defects on the basis of the positional information about said defects.
References Cited (Backward Citations)
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JPS4952612A
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US4507693A
Cited
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Cited
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Cited
US4558446A
Cited
US4631723A
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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) | 1992-02-14 | 1992-08-15 | 1993-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-14 | 1996-08-15 | 1997-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-14 | 2000-08-15 | 2001-02-14 | $7700.00 | Window Closed / Lapsed |