EP0335517A2
Expired / Lapsed
EP
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Servo address system
Assignee: Seagate Technology International
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Filing: 1989-03-08
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Granted: —
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Expires: 2009-03-08
Abstract
Abstract A servo address system for a computer disk drive unit having a plurality of memory storage disks comprises a servo head (12) in operative association with a dedicated servo surface (14) provided on one of the memory storage disks (16). Servo data is recorded on the dedicated servo surface in generally concentric tracks ("0" to "7") and defines a unique track address for each of the concentric tracks readable by the servo head. The servo data comprises a succession of synchronising bits (45) recorded in each of the tracks to define there-between a plurality of bit frames (44), and a plurality of servo bits ("A" to "D") recorded within each of the bit frames in one of first and second distinct patterns for detection and reading by the servo head in binary code. A selected successive plurality of the bit frames for each of the tracks defines an address and the servo bits thereof are recorded in a regular pattern which repeats for each address, wherein each address is represented by a unique plurality of digits in binary code.
Inventors
- 👤 Leroy Allen Volz
- 👤 Mark Edward Pease
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 12:50
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/58; G11B5/596; G11B5/59688; G11B27/00; G11B27/10; G11B27/19; G11B27/28; G11B27/30; G11B27/3027
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
189 words
A servo address system for a computer disk drive unit having a plurality of memory storage disks (16), the address system comprising a servo head (12) in operative association with a dedicated servo surface 14) provided on one of the storage disks, and servo data recorded in generally concentric tracks ("0" to "7") on the dedicated servo surface, the servo data being readable by the servo head and defining a unique track address for each of the concentric tracks, characterised in that the servo data comprises a timed succession of synchronising bits (45) recorded in each of said tracks to define there-between a plurality of bit frames (44), and a plurality of servo bits ("A" to "D") recorded within each of the bit frames in one of first and second distinct patterns for detection and reading by the servo head in binary code, a selected successive plurality of the bit frames for each of the tracks defining an address and having the servo bits thereof recorded in a regular pattern which repeats for each address, wherein each address is represented by a unique plurality of digits in binary code.
Claim 2
Dependent Claim
189 words
A servo address system for a computer disk drive unit having a plurality of memory storage disks (16), the address system comprising a servo head (12) in operative association with a dedicated servo surface 14) provided on one of the storage disks, and servo data recorded in generally concentric tracks ("0" to "7") on the dedicated servo surface, the servo data being readable by the servo head and defining a unique track address for each of the concentric tracks, characterised in that the servo data comprises a timed succession of synchronising bits (45) recorded in each of said tracks to define there-between a plurality of bit frames (44), and a plurality of servo bits ("A" to "D") recorded within each of the bit frames in one of first and second distinct patterns for detection and reading by the servo head in binary code, a selected successive plurality of the bit frames for each of the tracks defining an address and having the servo bits thereof recorded in a regular pattern which repeats for each address, wherein each address is represented by a unique plurality of digits in binary code.
Claim 3
Dependent Claim
26 words
A system according to claim 1 characterised in that the selected successive plurality of the bit frames defining the address are repeated throughout the associated track.
Claim 4
Dependent Claim
53 words
A system according to claim 1 or 2 characterised in that each of the bit frames includes a first portion (48) and a second portion (50) in succession, the servo bits recorded within each bit frame being recorded within the first and second portions in opposite ones of the first and second patterns.
Claim 5
Dependent Claim
102 words
A system according to claim 3 characterised in that the first pattern of servo bits in the first portion of a respective one of the bit frames followed by the second pattern of servo bits in the second portion of the respective one of the bit frames comprises the digit "0" in binary code, and in that the second pattern of servo bits in the first portion of the respective one of the bit frames followed by the first pattern of servo bits in the second portion of the respective one of the bit frames comprises the digit "1" in binary code.
Claim 6
Dependent Claim
70 words
A system according to claim 3 or 4 characterised in that the first pattern comprises servo bits having a relatively short duration when detected by the servo head during rotation of the storage disk providing the dedicated servo surface, and in that the second pattern comprises servo bits having a relatively long duration when detected by the servo head during rotation of the storage disk providing the dedicated servo surface.
Claim 7
Independent Claim
30 words
A system according to any of claims 1 to 5 characterised in that a plurality of the bit frames further include code bits (46) disposed at generally intermediate positions therein.
Claim 8
Dependent Claim
27 words
A system according to claim 6 characterised in that the code bits recorded in adjacent tracks on the dedicated servo surface are positioned in generally radial alignment.
Claim 9
Independent Claim
31 words
A system according to any of claims 1 to 7 characterised in that the synchronising bits recorded in adjacent tracks on the dedicated servo surface are positioned in generally radial alignment.
Claim 10
Independent Claim
45 words
A system according to any of claims 1 to 8 characterised by means for identifying a reference synchronising bit for each of the tracks to demarcate a starting point for rotation of the storage disk providing the dedicated servo surface relative to the servo head.
Claim 11
Independent Claim
79 words
A system according to any of claims 1 to 9 characterised in that the servo bits are recorded within the bit frames in a regular repeating pattern for each of a plurality of adjacent ones of the tracks to define a unique address for the adjacent tracks, and in that means are provided for generating and comparing position error signals in quadrature to obtain additional signals representable in binary to distinguish each of the adjacent tracks from one another.
Claim 12
Dependent Claim
95 words
A memory storage disk for a computer disk drive unit, comprising a dedicated servo surface (14) on one side of the disk, and servo data recorded on the dedicated servo surface in a plurality of concentric tracks ("0" to "7"), characterised in that the servo data defines, for each of the tracks, a track address repeated in succession throughout the track, the track address being defined by a repeating succession of a selected plurality of bit frames (44), each having at least one servo bit ("A" to "D") recorded therein and representable in binary code.
Claim 13
Dependent Claim
95 words
A memory storage disk for a computer disk drive unit, comprising a dedicated servo surface (14) on one side of the disk, and servo data recorded on the dedicated servo surface in a plurality of concentric tracks ("0" to "7"), characterised in that the servo data defines, for each of the tracks, a track address repeated in succession throughout the track, the track address being defined by a repeating succession of a selected plurality of bit frames (44), each having at least one servo bit ("A" to "D") recorded therein and representable in binary code.
Claim 14
Dependent Claim
75 words
A disk according to claim 11 characterised in that the servo bits are recorded within the bit frames in a regular repeating pattern for each of a plurality of adjacent ones of the tracks to define a unique address for the adjacent tracks, and in that means are provided for generating and comparing position error signals in quadrature to obtain additional signals representable in binary to distinguish each of the adjacent tracks from one another.
Claim 15
Dependent Claim
63 words
A disk according to claim 11 or 12 characterised in that each of the bit frames includes a first portion (48) and a second portion (50) in succession, the at least one servo bit recorded within each bit frame comprising a plurality of the servo bits recorded within the first and second portions in opposite ones of a first and a second pattern.
Claim 16
Dependent Claim
30 words
A disk according to any of claims 11 to 13, characterised in that a plurality of the bit frames further include code bits (46) disposed at generally intermediate positions therein.
Claim 17
Independent Claim
206 words
A method of tracking a plurality of data heads relative to a corresponding plurality of data surfaces on a plurality of memory storage disks arranged in a stack within a computer disk drive unit for rotation together about a common axis, the method comprising the steps of recording servo data in a plurality of generally concentric tracks ("0" to "7") on one surface (14) of a selected one of the memory storage disks (16), the one surface comprising a dedicated servo surface, detecting and monitoring the servo data with a servo head (12) to identify the track aligned therewith, and displacing the servo head into alignment with a specified track so as to displace the data heads (20) concurrently into alignment with respective tracks on the corresponding data surfaces, characterised in that in the recording step the servo data is recorded onto the dedicated servo surface in the form of a succession of individual bit frames (44) for each of the tracks, each of the bit frames including the servo bits representable in binary code and a selected successive plurality of the bit frames defining an address which repeats throughout the respective track, the pattern of servo bits within the address being unique to that track.
Claim 18
Independent Claim
206 words
A method of tracking a plurality of data heads relative to a corresponding plurality of data surfaces on a plurality of memory storage disks arranged in a stack within a computer disk drive unit for rotation together about a common axis, the method comprising the steps of recording servo data in a plurality of generally concentric tracks ("0" to "7") on one surface (14) of a selected one of the memory storage disks (16), the one surface comprising a dedicated servo surface, detecting and monitoring the servo data with a servo head (12) to identify the track aligned therewith, and displacing the servo head into alignment with a specified track so as to displace the data heads (20) concurrently into alignment with respective tracks on the corresponding data surfaces, characterised in that in the recording step the servo data is recorded onto the dedicated servo surface in the form of a succession of individual bit frames (44) for each of the tracks, each of the bit frames including the servo bits representable in binary code and a selected successive plurality of the bit frames defining an address which repeats throughout the respective track, the pattern of servo bits within the address being unique to that track.
References Cited (Backward Citations)
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