US4682253A
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US
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Servo positioning system for disk drive system
Assignee: QED INTELLECTUAL PROPERTY SERVICES Ltd
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Filing: 1986-04-23
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Granted: 1987-07-21
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Expires: 2006-04-23
Abstract
Abstract An improved servo positioning system for a Winchester disk drive system is disclosed. A plurality of concentric servo tracks are provided on the surface of one disk. Each track is comprised of an equal number of frames of a preterminded length. Four basic frame patterns are utilized. In addition, a frame may also have a code bit in a predetermined position, in order to define the frame as a "one" or "zero" frame. The servo data is read by a dedicated servo head, digitized and fed to a logic array which receives as its only other input an 8 megahertz clock signal. The logic array detects the sync signals present in each frame and generates index, guardband and no sync signals therefrom. In addition, a plurality of windows, each corresponding to a predetermined portion of each frame, is generated. Those window signals are utilized to control a window control circuit which sequentially enables four similar peak dectors, one for each window. The peak detected signals are utilized to form the phase and quadrature signals utilized to provide proper positioning of the heads over the desired track.
Inventors
- 👤 James B. Leslie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:34
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/58; G11B5/596; G11B5/59605; G11B5/59611
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
162 words
A servo positioning system for operating the positioning mechanism of a disk drive having at least one disk rotating at a constant speed, transducer means associated with each surface of said at least one disk, one surface of said at least one disk containing only servo information with the remaining disk surfaces being available for data storage, and means for decoding said servo information for controlling the operation of said positioning mechanism, said servo information comprising: a plurality of concentric tracks recorded on said servo surface, each of said concentric tracks having a like plurality of frames of a predetermined equal time period occurring over the length of each of said concentric tracks; each of said frames including one of a plurality of different basic servo patterns each track having only a single pattern repeating thereon; and each of said frames additionally containing syncronization and coding information such that said detecting means can extract indexing and guardband information encoded on said tracks.
Claim 2
Dependent Claim
162 words
A servo positioning system for operating the positioning mechanism of a disk drive having at least one disk rotating at a constant speed, transducer means associated with each surface of said at least one disk, one surface of said at least one disk containing only servo information with the remaining disk surfaces being available for data storage, and means for decoding said servo information for controlling the operation of said positioning mechanism, said servo information comprising: a plurality of concentric tracks recorded on said servo surface, each of said concentric tracks having a like plurality of frames of a predetermined equal time period occurring over the length of each of said concentric tracks; each of said frames including one of a plurality of different basic servo patterns each track having only a single pattern repeating thereon; and each of said frames additionally containing syncronization and coding information such that said detecting means can extract indexing and guardband information encoded on said tracks.
Claim 3
Dependent Claim
38 words
The servo positioning system of claim 1, wherein said synchronous information occurs at the start of each frame and all frames in adjacent tracks are aligned such that said synchronous information forms a continuous transition across track boundaries.
Claim 4
Dependent Claim
21 words
The servo positioning system of claim 2, wherein said sync information is comprised of two pulses spaced a predetermined time apart.
Claim 5
Dependent Claim
28 words
The servo positioning of claim 1, wherein said code information is comprised of a single pulse which occurs a predetermined time after the occurrence of said sync information.
Claim 6
Dependent Claim
36 words
The servo positioning system of claim 1, wherein the presence of code information in each frame forms a pattern which is used by said detecting means to detect the index information for said servo positioning system.
Claim 7
Dependent Claim
36 words
The servo positioning system of claim 1, wherein the presence of code information in each frame forms a pattern which is used by said detecting means to detect the guardband information for said servo positioning system.
Claim 8
Dependent Claim
18 words
The servo positioning system of claim 5, wherein the pattern indicating the index is eight consecutive code pulses.
Claim 9
Dependent Claim
22 words
The servo positioning system of claim 6, wherein the pattern indicating a guardband is two alternate code pulses and no code pulses.
Claim 10
Dependent Claim
16 words
The servo positioning system of claim 3, wherein each of said pulses is a dibit transition.
Claim 11
Dependent Claim
14 words
The servo positioning system of claim 4, wherein said pulse is a dibit transition.
Claim 12
Dependent Claim
58 words
The servo positioning system of claim 1, wherein said plurality of concentric tracks comprises a plurality of guardband tracks at the outermost edge of said servo surface followed by a plurality of normal servo tracks and wherein one of said guardband tracks contains a frame pattern different than that of the other guardband tracks, indicative of track zero.
Claim 13
Dependent Claim
36 words
The servo positioning system of claim 11, wherein said plurality of guardband tracks, at the outermost edge of said servo surface is composed of eight concentric tracks, each track being of a plurality of like frames.
Claim 14
Dependent Claim
32 words
The servo positioning system of claim 11, wherein said plurality of normal servo tracks is composed of a plurality of tracks of a single frame pattern, which pattern repeats every four tracks.
Claim 15
Dependent Claim
20 words
The servo positioning system of claim 13, wherein the plurality of concentric normal servo tracks is at least approximately 874.
Claim 16
Dependent Claim
15 words
The servo positioning system of claim 1, wherein there are 2,778 frames per concentric track.
Claim 17
Dependent Claim
74 words
The servo positioning system of claim 1, wherein said detecting means comprises: means for digitizing said said servo information; logic means for analyzing said digitized information to extract the index, guardband and sync information, said analyzing means also generating a plurality of timing windows; and a plurality of peak detecting means, being activated in turn during by said plurality of timing windows, for detecting the occurrence of position pulses within said digitized servo information.
Claim 18
Dependent Claim
20 words
The servo positioning system of claim 16, wherein the only other input to said logic means is a clocking signal.
Claim 19
Dependent Claim
170 words
A servo positioning system for controlling the positioning mechanism of a disk drive having at least one rotating hard disk having a plurality of concentric tracks thereon, transducer means associated with each surfaces of said at least one disk, one surface of said at least one disk being dedicated for recording servo information thereon and means for decoding said servo information for controlling the operation of said positioning mechanism, wherein said servo information comprises: a plurality of like frames of a predetermined equal time period recorded on a plurality of the outermost tracks of said rotating hard disk; a like plurality of frames of a similar predetermined equal time period recorded on a plurality of said concentric tracks adjoining said plurality of like frames recorded on a plurality of said outermost tracks, said tracks comprising a constant repeating of different frame patterns from track to track; and each of said different frame patterns contain sync and code information in addition to the position information contained in said different frame patterns.
Claim 20
Dependent Claim
170 words
A servo positioning system for controlling the positioning mechanism of a disk drive having at least one rotating hard disk having a plurality of concentric tracks thereon, transducer means associated with each surfaces of said at least one disk, one surface of said at least one disk being dedicated for recording servo information thereon and means for decoding said servo information for controlling the operation of said positioning mechanism, wherein said servo information comprises: a plurality of like frames of a predetermined equal time period recorded on a plurality of the outermost tracks of said rotating hard disk; a like plurality of frames of a similar predetermined equal time period recorded on a plurality of said concentric tracks adjoining said plurality of like frames recorded on a plurality of said outermost tracks, said tracks comprising a constant repeating of different frame patterns from track to track; and each of said different frame patterns contain sync and code information in addition to the position information contained in said different frame patterns.
Claim 21
Dependent Claim
38 words
The servo positioning system of claim 18, wherein said code information is in the form of a pulse and the presence or absence of such pulse in a frame forms a pattern indicative of index and guardband signals.
Claim 22
Dependent Claim
38 words
The servo positioning system of claim 18, wherein said synchronous information occurs at the start of each frame and all frames in adjacent tracks, are aligned such that said synchronous information forms a continuous transition across track boundaries.
Claim 23
Dependent Claim
28 words
The servo positioning of claim 18, wherein said code information is comprised of a single pulse which occurs a predetermined time after the occurrence of said sync information.
Claim 24
Dependent Claim
36 words
The servo positioning system of claim 18, wherein the presence of code information in each frame forms, a pattern which is used by said detecting means to detect the guardband information for said servo positioning system.
Claim 25
Dependent Claim
18 words
The servo positioning system of claim 19, wherein the pattern indicating the index is eight consecutive code pulses.
Claim 26
Dependent Claim
22 words
The servo positioning system of claim 19, wherein the pattern indicating a guardband is two alternate code pulses and no code pulses.
Claim 27
Dependent Claim
47 words
The servo positioning system of claim 18, wherein said plurality of guardband tracks, at the outermost edge of said servo surface is composed of seven concentric tracks of a plurality of like frames and one concentric track having a like plurality of frames having a different pattern.
Claim 28
Dependent Claim
32 words
The servo positioning system of claim 18, wherein said plurality of normal servo tracks is composed of a plurality of tracks of a single frame pattern, which pattern repeats every four tracks.
Claim 29
Dependent Claim
74 words
The servo positioning system of claim 18, wherein said detecting means comprises: means for digitizing said said servo information; logic means for analyzing said digitized information to extract the index, guardband and sync information, said analyzing means also generating a plurality of timing windows; and a plurality of peak detecting means, being activated in turn during by said plurality of timing windows, for detecting the occurrence of position pulses within said digitized servo information.
Claim 30
Dependent Claim
20 words
The servo positioning system of claim 27, wherein the only other input to said logic means is a clocking signal.
Claim 31
Independent Claim
162 words
A method for controlling the positioning system of a disk drive having at least one rotating hard disk having a plurality of concentric tracks thereon, transducer means associated with each surface of said at least one disk, one surface of said at least one disk being dedicated for recording servo information thereon, comprising the steps of: recording a plurality of like frames of a predetermined equal time period on the outermost plurality of concentric tracks of said rotating hard disk; recording a like plurality of frames of a similar predetermined equal time period on a plurality of concentric tracks adjoining said plurality of like frames recorded on a plurality of said outermost tracks, said tracks comprising a repetition of different frame patterns from track to track, wherein each of said different frame patterns contains sync and code information in addition to position information contained in said different frame patterns; and decoding said servo information for controlling the operation of said positioning system.
Claim 32
Independent Claim
162 words
A method for controlling the positioning system of a disk drive having at least one rotating hard disk having a plurality of concentric tracks thereon, transducer means associated with each surface of said at least one disk, one surface of said at least one disk being dedicated for recording servo information thereon, comprising the steps of: recording a plurality of like frames of a predetermined equal time period on the outermost plurality of concentric tracks of said rotating hard disk; recording a like plurality of frames of a similar predetermined equal time period on a plurality of concentric tracks adjoining said plurality of like frames recorded on a plurality of said outermost tracks, said tracks comprising a repetition of different frame patterns from track to track, wherein each of said different frame patterns contains sync and code information in addition to position information contained in said different frame patterns; and decoding said servo information for controlling the operation of said positioning system.
Claim 33
Dependent Claim
68 words
The method of claim 29, wherein said decoding step comprises the steps of: digitizing said servo information; detecting the presence of sync and code information and generating index, guard and and sync signals therefrom; generating a plurality of timing windows using said sync signals; and peak detecting said position information, under control of said plurality of timing windows, for generating position control information for controlling said positioning system.
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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) | 1990-07-20 | 1991-01-19 | 1991-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-20 | 1995-01-19 | 1995-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-20 | 1999-01-19 | 1999-07-21 | $7700.00 | Window Closed / Lapsed |