US4638384A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Head positioning mechanism for rotating disk data storage system
Assignee: Rodime PLC
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Filing: 1985-11-19
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Granted: 1987-01-20
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Expires: 2005-11-19
Abstract
Abstract A fine position closed loop servo system is disclosed for magnetic disk storage media having a plurality of data storage disks in which a first servo burst is contained on the surface of one of the data storage disks, the servo burst data being spaced at radial positions one-half track displaced from each of the odd-numbered concentric track centerlines and a second servo burst signal is contained on the surface of another of the data storage disks, the second servo burst signal being recorded at radial positions one-half track displaced from the even-numbered concentric track centerlines. Both the first and second servo burst data are read simultaneously utilizing the data transducers associated with the surfaces of the respective data storage disks and the envelopes of each of the servo burst signals are simultaneously, separately detected. The envelope signals thus detected are compared in order to generate a position error signal which is applied to the head actuating mechanism of the disk drive in order to promote and maintain track centerline alignment of an enabled data transducer during operation of the magnetic disk storage means.
Inventors
- 👤 Alexander Stewart
- 👤 Duncan S. Furness
- 👤 Sham P. Bhatia
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:05
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/58; G11B5/596; G11B5/59688
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
300 words
A fine position closed loop servo system for use in conjunction with a closed loop servo positioning system for a magnetic disk storage media having at least two data storage disks rotatingly driven at a constant velocity with a plurality of concentric data tracks on at least one of the surfaces of each of said data storage disks, at least one data transducer associated with and in close proximity to each of said data storage disks, said data transducers being mounted to a common head mounting structure for movement by driver means across said plurality of concentric tracks on each of said at least two data storage disks, comprising: first servo burst signals on a surface of a first of said at least two data storage disks, said first servo burst signals being recorded on said first data storage disk at radial positions one-half track displaced from one of the odd and even numbered concentric track centerlines; second servo burst signals on a surface of another of said at least two data storage disks, said second servo burst signals being recorded at radial positions one-half track displaced from the not already selected one of the odd and even numbered concentric track centerlines; means for simultaneously enabling the data transducers associated with the surfaces of said at least two data storage disks containing said first and second servo burst signals for reading said servo burst signals; means for simultaneously separately detecting the absolute value of the envelope of each of said first and second servo burst signals; and means for comparing each of said detected envelope signals in order to generate a position error signal for application to said driver means for promoting and maintaining track centerline alignment of an enabled data transducer during operation of said magnetic disk storage means.
Claim 2
Dependent Claim
300 words
A fine position closed loop servo system for use in conjunction with a closed loop servo positioning system for a magnetic disk storage media having at least two data storage disks rotatingly driven at a constant velocity with a plurality of concentric data tracks on at least one of the surfaces of each of said data storage disks, at least one data transducer associated with and in close proximity to each of said data storage disks, said data transducers being mounted to a common head mounting structure for movement by driver means across said plurality of concentric tracks on each of said at least two data storage disks, comprising: first servo burst signals on a surface of a first of said at least two data storage disks, said first servo burst signals being recorded on said first data storage disk at radial positions one-half track displaced from one of the odd and even numbered concentric track centerlines; second servo burst signals on a surface of another of said at least two data storage disks, said second servo burst signals being recorded at radial positions one-half track displaced from the not already selected one of the odd and even numbered concentric track centerlines; means for simultaneously enabling the data transducers associated with the surfaces of said at least two data storage disks containing said first and second servo burst signals for reading said servo burst signals; means for simultaneously separately detecting the absolute value of the envelope of each of said first and second servo burst signals; and means for comparing each of said detected envelope signals in order to generate a position error signal for application to said driver means for promoting and maintaining track centerline alignment of an enabled data transducer during operation of said magnetic disk storage means.
Claim 3
Dependent Claim
270 words
A fine position closed loop servo control system for use in conjunction with a closed loop positioning system for a magnetic disk storage media having at least one data storage disk rotatingly driven at a constant velocity with a plurality of concentric data tracks on both surfaces thereof, at least one data transducer associated with and in close proximity to each of the surfaces of said data storage disk, said data transducers being mounted to a common head mounting structure for movement by driver means across said plurality of concentric tracks on said data storage disk, comprising: first servo burst signals on a first surface of said data storage disk, said first servo burst signals being recorded at radial positions one-half track displaced from one of the odd and even numbered concentric track centerlines; second servo burst signals on a second surface of said data storage disk, said second servo burst signals being recorded at radial positions one-half track displaced from the not already selected one of the odd and even numbered concentric track centerlines; means for simultaneously enabling the data transducers associated with the surfaces of said data storage disk containing said first and second servo burst signals for reading said servo burst signals; means for simultaneously separately detecting the absolute value of the envelope of each of said first and second servo burst signals; and means for comparing each of said detected envelope signals in order to generate a position error signal for application to said driver means for promoting and maintaining track centerline alignment of an enabled data transducer during operation of said magnetic disk storage means.
Claim 4
Dependent Claim
270 words
A fine position closed loop servo control system for use in conjunction with a closed loop positioning system for a magnetic disk storage media having at least one data storage disk rotatingly driven at a constant velocity with a plurality of concentric data tracks on both surfaces thereof, at least one data transducer associated with and in close proximity to each of the surfaces of said data storage disk, said data transducers being mounted to a common head mounting structure for movement by driver means across said plurality of concentric tracks on said data storage disk, comprising: first servo burst signals on a first surface of said data storage disk, said first servo burst signals being recorded at radial positions one-half track displaced from one of the odd and even numbered concentric track centerlines; second servo burst signals on a second surface of said data storage disk, said second servo burst signals being recorded at radial positions one-half track displaced from the not already selected one of the odd and even numbered concentric track centerlines; means for simultaneously enabling the data transducers associated with the surfaces of said data storage disk containing said first and second servo burst signals for reading said servo burst signals; means for simultaneously separately detecting the absolute value of the envelope of each of said first and second servo burst signals; and means for comparing each of said detected envelope signals in order to generate a position error signal for application to said driver means for promoting and maintaining track centerline alignment of an enabled data transducer during operation of said magnetic disk storage means.
Claim 5
Dependent Claim
294 words
A fine position closed loop servo system for use in conjunction with a closed loop servo positioning system for a magnetic disk storage media having at least two data storage disks rotatingly driven at a constant velocity with a plurality of concentric data tracks on at least one of the surfaces of each of said data storage disks, at least one data transducer associated with and in close proximity to each of said data storage disks, said data transducers being mounted to a common head mounting structure for movement by driver means across said plurality of concentric tracks on each of said at least two data storage disks, comprising: first servo burst signals on a surface of a first of said at least two data storage disks, said first servo burst signals being recorded on said first data storage disk at radial positions one-half track displaced from one of the odd and even numbered concentric track centerlines; second servo burst signals on a surface of another of said at least two data storage disks, said second servo burst signals being recorded at radial positions one-half track displaced from the not already selected one of the odd and even numbered concentric track centerlines; means for simultaneously reading said first and second servo burst signals; means for processing the first and second servo burst signals read from said at least two storage disks to determine the peak value of each of said first and second servo burst signals; and means for sampling combined peak value signals of said first and second servo burst signals to produce a position error signal for application to said driver means for promoting and maintaining track centerline alignment of an enabled data transducer during operation of said magnetic disk storage means.
Claim 6
Dependent Claim
294 words
A fine position closed loop servo system for use in conjunction with a closed loop servo positioning system for a magnetic disk storage media having at least two data storage disks rotatingly driven at a constant velocity with a plurality of concentric data tracks on at least one of the surfaces of each of said data storage disks, at least one data transducer associated with and in close proximity to each of said data storage disks, said data transducers being mounted to a common head mounting structure for movement by driver means across said plurality of concentric tracks on each of said at least two data storage disks, comprising: first servo burst signals on a surface of a first of said at least two data storage disks, said first servo burst signals being recorded on said first data storage disk at radial positions one-half track displaced from one of the odd and even numbered concentric track centerlines; second servo burst signals on a surface of another of said at least two data storage disks, said second servo burst signals being recorded at radial positions one-half track displaced from the not already selected one of the odd and even numbered concentric track centerlines; means for simultaneously reading said first and second servo burst signals; means for processing the first and second servo burst signals read from said at least two storage disks to determine the peak value of each of said first and second servo burst signals; and means for sampling combined peak value signals of said first and second servo burst signals to produce a position error signal for application to said driver means for promoting and maintaining track centerline alignment of an enabled data transducer during operation of said magnetic disk storage means.
Claim 7
Dependent Claim
32 words
The system of claim 1, wherein said means for simultaneously separately detecting comprises a pair of peak detectors, each connected to receive only one of said first and second servo burst signals.
Claim 8
Dependent Claim
26 words
The system of claim 1, wherein said first and second servo burst signals are uniform in length and of a duration of 100 microseconds or less.
Claim 9
Dependent Claim
32 words
The system of claim 2, wherein said means for simultaneously separately detecting comprises a pair of peak detectors, each connected to receive only one of said first and second servo burst signals.
Claim 10
Dependent Claim
26 words
The system of claim 2, wherein said first and second servo burst signals are uniform in length and of a duration of 100 microseconds or less.
Claim 11
Dependent Claim
37 words
The system of claim 3, wherein said means for processing said first and second servo burst signals comprises a pair of peak detectors, each connected to receive only one of said first and second servo burst signals.
Claim 12
Dependent Claim
32 words
The system of claim 3, wherein said means for simultaneously separately detecting comprises a pair of peak detectors, each connected to receive only one of said first and second servo burst signals.
Claim 13
Dependent Claim
93 words
The system of claim 3, wherein said means for sampling combined peak value signals comprises: a pair of peak detector means each connected to receive only one of said first and second servo burst signals; a first summing means connected to said pair of peak detector means in order to produce a servo burst difference signal; means for digitizing said servo burst difference signal to produce an alignment signal; and means for comparing said alignment signal to predetermined generated reference signals to obtain a position error signal for application to said driver means.
Claim 14
Dependent Claim
13 words
The system of claim 10, wherein said means for digitizing comprises integrator means.
Claim 15
Dependent Claim
16 words
The system of claim 11, further including sample and hold means connected to said integrator means.
Claim 16
Dependent Claim
21 words
The system of claim 10, wherein computer means generates said reference signals until said generated reference signals equal said alignment signal.
Claim 17
Dependent Claim
37 words
The system of claim 10, wherein a single digital-to-analog convertor means is utilized by said system to generate both said reference signals for use by said means for comparing and instructions for use by said driver means.
Claim 18
Dependent Claim
37 words
The system of claim 14, further comprising means connected between said single digital-to-analog convertor means and said driver means for processing the analog signals generated by said single digital-to-analog convertor means for application to said driver means.
Claim 19
Dependent Claim
31 words
The system of claim 15, further comprising computer means connected to said single analog-to-digital convertor means for generating signals proportional to both coarse and fine positioning instructions for said driving means.
Claim 20
Independent Claim
303 words
A method for the fine positioning of a closed loop servo system for use in conjunction with a closed loop servo positioning system for a magnetic disk storage media having at least two data storage disks rotatingly driven at a constant velocity with a plurality of concentric data tracks on at least one of the surfaces of each of said data storage disks, at least one data transducer associated with and in close proximity to each of said data storage disks, said data transducers being mounted to a common head mounting structure for movement by driver means across said plurality of concentric tracks on each of said at least two data storage disks, comprising the steps of: reading first servo burst signals on a surface of a first of said at least two data storage disks, said first servo burst signals being recorded on said first data storage disk at radial positions one-half track displaced from one of the odd and even numbered concentric track centerlines; reading second servo burst signals on a surface of another said at least two data storage disks, said second servo burst signals being recorded at radial positions one-half track displaced from the not already selected one of the odd and even numbered concentric track centerlines; simultaneously enabling the data transducers associated with the surfaces of said at least two data storage disks containing said first and second servo burst signals for reading said servo burst signals; simultaneously separately detecting the absolute value of the envelope of each of said first and second servo burst signals; and comparing each of said detected envelope signals in order to generate a position error signal for application to said driver means for promoting and maintaining track centerline alignment of an enabled data transducer during operation of said magnetic disk storage means.
Claim 21
Independent Claim
303 words
A method for the fine positioning of a closed loop servo system for use in conjunction with a closed loop servo positioning system for a magnetic disk storage media having at least two data storage disks rotatingly driven at a constant velocity with a plurality of concentric data tracks on at least one of the surfaces of each of said data storage disks, at least one data transducer associated with and in close proximity to each of said data storage disks, said data transducers being mounted to a common head mounting structure for movement by driver means across said plurality of concentric tracks on each of said at least two data storage disks, comprising the steps of: reading first servo burst signals on a surface of a first of said at least two data storage disks, said first servo burst signals being recorded on said first data storage disk at radial positions one-half track displaced from one of the odd and even numbered concentric track centerlines; reading second servo burst signals on a surface of another said at least two data storage disks, said second servo burst signals being recorded at radial positions one-half track displaced from the not already selected one of the odd and even numbered concentric track centerlines; simultaneously enabling the data transducers associated with the surfaces of said at least two data storage disks containing said first and second servo burst signals for reading said servo burst signals; simultaneously separately detecting the absolute value of the envelope of each of said first and second servo burst signals; and comparing each of said detected envelope signals in order to generate a position error signal for application to said driver means for promoting and maintaining track centerline alignment of an enabled data transducer during operation of said magnetic disk storage means.
Claim 22
Dependent Claim
33 words
The system of claim 1, further including means for inverting said position error signal prior to its application to said driver means if said enabled data transducer is centering on an even track.
Claim 23
Dependent Claim
39 words
The system of claim 1, wherein said error position signal functions to cause said driver means to move said enabled data transducer towards the center of the disk if said enabled data transducer is centering on an even track.
Claim 24
Dependent Claim
33 words
The system of claim 1, further including means for inverting said position error signal prior to its application to said driver means if said enabled data transducer is centering on an odd track.
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) | 1990-01-19 | 1990-07-21 | 1991-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-19 | 1994-07-21 | 1995-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-19 | 1998-07-21 | 1999-01-20 | $7700.00 | Window Closed / Lapsed |