Patent US4238809A successfully refreshed from Google Patents.
US4238809A
Expired / Lapsed
US
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Servo track configuration for magnetic disk apparatus
Assignee: Toshiba Corp
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Filing: 1979-03-05
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Granted: 1980-12-09
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Expires: 1999-03-05
Abstract
Abstract A servo track apparatus comprising at least one unit pattern area including 2n (n=2, 3, 4, . . . ) servo tracks T i (i=0, 1, . . . 2n-1) and 2n 2 flux transitions R jk (j=0, 1, . . . 2n-1; k=0, 1, . . . n-1). The tracks and flux transitions satisfy a condition TT requiring that track T p be adjacent to track T p+1 ; a condition TR requiring that transition R pq occur on track T p+q (mod 2n); a condition RR requiring that transitions R pq and R pr (r≠q) have the same polarity and occur at the same position; and a condition RR requiring that transitions R pr and R qr (q≠p) occur at different positions.
Inventors
- 👤 Masao Fujiki
- 👤 Hiromi Hamaoka
- 👤 Toshiaki Hattori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:02
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/58; G11B5/596; G11B5/59633
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
113 words
A servo track configuration comprising at least one unit pattern area including 2n (n=2, 3, 4, . . . ) servo tracks T i (i=0, 1, . . . 2n-1) and 2n 2 flux transitions R jk (j=0, 1, . . . 2n-1; k=0, 1, . . . n-1) satisfying the following four conditions: Condition TT: track T p being adjacent to track T p+1 ; Condition TR: transition R pq occurring on track T p+q (mod 2n); Condition RR: transition R pq and transition R pr (r≠q) having the same polarity and occurring at the same position; and Condition RR: transition R pr and transition R qr (q≠p) occurring at different positions.
Claim 2
Dependent Claim
113 words
A servo track configuration comprising at least one unit pattern area including 2n (n=2, 3, 4, . . . ) servo tracks T i (i=0, 1, . . . 2n-1) and 2n 2 flux transitions R jk (j=0, 1, . . . 2n-1; k=0, 1, . . . n-1) satisfying the following four conditions: Condition TT: track T p being adjacent to track T p+1 ; Condition TR: transition R pq occurring on track T p+q (mod 2n); Condition RR: transition R pq and transition R pr (r≠q) having the same polarity and occurring at the same position; and Condition RR: transition R pr and transition R qr (q≠p) occurring at different positions.
Claim 3
Dependent Claim
61 words
A servo track configuration according to claim 1, wherein said unit pattern area further includes n transitions C l (l=0, 1, . . . 2n-1) satisfying the following conditions: Condition TC: transition C p occurring on track T p ; and Condition CC: transition C p and transition C q (q≠p) having the same polarity and occurring at the same position.
Claim 4
Dependent Claim
17 words
A servo track configuration according to claim 2, wherein said unit pattern area is repetitive along tracks.
Claim 5
Dependent Claim
17 words
A servo track configuration according to claim 3, wherein said unit pattern area is repetitive across tracks.
Claim 6
Dependent Claim
22 words
A servo track configuration according to claim 4, wherein said track T p and track T q (q≠p) have the same width.
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) | 1983-12-09 | 1984-06-09 | 1984-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-09 | 1988-06-09 | 1988-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-09 | 1992-06-09 | 1992-12-09 | $7700.00 | Window Closed / Lapsed |