EP0420693A2
Expired / Lapsed
EP
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Disk data storage system with head positioning system
Assignee: International Business Machines Corp
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Filing: 1990-09-28
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Granted: —
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Expires: 2010-09-28
Abstract
Abstract A servo pattern comprises two sets of servo patterns, A and B, and C and D. The first servo pattern (A and B) is symmetric about the centreline 3 of the data track. The second servo pattern (C and D) is offset by a known amount from the centreline of the data track. In an initial calibration phase, information from both sets of servo patterns is used to measure the value of K, which is the coefficient of proportionality between the servo position error signal and the true displacement of the head from the data track centreline.
Inventors
- 👤 Masashi Kisaka
- 👤 Takeshi Mizuno
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 00:47
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/54; G11B5/55; G11B5/5521; G11B5/5552; G11B5/5526; G11B5/553; G11B5/5534
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
177 words
A disk data storage system including: a data storage disk having concentric data tracks with first and second servo patterns recorded on opposite sides of a line (3) representing the centre of a data track and third and fourth servo patterns recorded on opposite sides of a line (4) separated from said line representing the centre of said data track; a transducing head (5) which generates first, second, third and fourth detect signals on passing said first, second, third, and fourth servo patterns respectively; and a head positioning system in which a position error signal X=Y/K is generated wherein Y is calculated from said first and second detect signals and K is a coefficient, said head positioning system including calculating means which receives said first, second, third and fourth detect signals to generate the value of said coefficient K; and wherein said calculating means generates the value of coefficient K during an initial calibration period, and said value of coefficient K is stored digitally and used thereafter to generate the position error signal X during read/write operations.
Claim 2
Dependent Claim
177 words
A disk data storage system including: a data storage disk having concentric data tracks with first and second servo patterns recorded on opposite sides of a line (3) representing the centre of a data track and third and fourth servo patterns recorded on opposite sides of a line (4) separated from said line representing the centre of said data track; a transducing head (5) which generates first, second, third and fourth detect signals on passing said first, second, third, and fourth servo patterns respectively; and a head positioning system in which a position error signal X=Y/K is generated wherein Y is calculated from said first and second detect signals and K is a coefficient, said head positioning system including calculating means which receives said first, second, third and fourth detect signals to generate the value of said coefficient K; and wherein said calculating means generates the value of coefficient K during an initial calibration period, and said value of coefficient K is stored digitally and used thereafter to generate the position error signal X during read/write operations.
Claim 3
Dependent Claim
85 words
A disk data storage system according to Claim 1, wherein said calculating means includes first means for generating signals Y₁=(A-B)/(A+B) and Y₂=(C-D)/(C+D) wherein A represents the peak value of said first detect signal, B represents the peak value of said second detect signal, C represents the peak value of said third detect signal and D represents the peak value of said fourth detect signal, and second means (43) for calculating the coefficient K=Y₁/X₁, wherein X₁ is a predetermined value, when |Y₁| is equal to |Y₂|.
Claim 4
Dependent Claim
94 words
A disk data storage system according to Claim 1, wherein said calculating means includes first means for generating signals Y₁=(A-B)/(A+B) and Y₂=(C-D)/(C+D) wherein A represents the peak value of said first detect signal, B represents the peak value of said second detect signal, C represents the peak value of said third detect signal and D represents the peak value of said fourth detect signal, and second means (58) for receiving the value of signal Y₂ when the value Y₁ is equal to zero, and calculating said coefficient K=Y₂/X₂, wherein X₂ has a predetermined value.
References Cited (Backward Citations)
No citation records indexed.
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