US5032776A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Attenuation filter
Assignee: Unisys Corp
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Filing: 1990-06-07
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Granted: 1991-07-16
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Expires: 2010-06-07
Abstract
Abstract Disclosed is a disk drive servo system including a "switched-capacitor" digital filter means adapted to attenuate resonant vibration and enhance system stability and position loop control.
Inventors
- 👤 Gary B. Garagnon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:48
CPC Classifications
H; H03; H03H; H03H19/00; H03H19/004; G; G11; G11B; G11B21/00; G11B21/02; G11B21/08; G11B21/081; G11B21/083; G11B21/085; G11B21/10; G11B21/106; G11B5/00; G11B5/48; G11B5/54; G11B5/55; G11B5/5521; G11B5/5526; G11B5/553; G11B5/58; G11B5/596; G11B5/59605; G11B5/59622; G11B5/5582; G11B7/00; G11B7/08; G11B7/09; G11B7/0941
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
168 words
A disk drive positioning arrangement apt to be disturbed by resonant vibrations, this arrangement including a closed loop servo system with a "switched-capacitor" digital filter capability using filter means, which filter means is selected and arranged to attenuate resonant vibration and enhance the stability of the closed loop servo system for the disk drive positioning arrangement; said servo system comprising: a prescribed amplifier means A; an elliptical, switched-capacitor digital filter means K, wherein the amplifier means A and the filter means K are connected in series to form a series circuit, which series circuit is connected between an input stage R and an output means C: a first summing means SP-1 connected between the amplifier means A and the filter means K; a first integrator means I disposed in feedback relation with the filter means K; a second summing means SP-2 connected in parallel with said series circuit and connected between R and C; and a second integrator means DS connected between the summing means SP-1 and SP-2.
Claim 2
Dependent Claim
168 words
A disk drive positioning arrangement apt to be disturbed by resonant vibrations, this arrangement including a closed loop servo system with a "switched-capacitor" digital filter capability using filter means, which filter means is selected and arranged to attenuate resonant vibration and enhance the stability of the closed loop servo system for the disk drive positioning arrangement; said servo system comprising: a prescribed amplifier means A; an elliptical, switched-capacitor digital filter means K, wherein the amplifier means A and the filter means K are connected in series to form a series circuit, which series circuit is connected between an input stage R and an output means C: a first summing means SP-1 connected between the amplifier means A and the filter means K; a first integrator means I disposed in feedback relation with the filter means K; a second summing means SP-2 connected in parallel with said series circuit and connected between R and C; and a second integrator means DS connected between the summing means SP-1 and SP-2.
Claim 3
Dependent Claim
36 words
The arrangement of claim 1, wherein said filter means K has second-order low-pass outputs and second-order high-pass outputs, said second-order low-pass outputs being summed with said second-order high-pass outputs to form a fourth-order, elliptic, multi-notch filter.
Claim 4
Dependent Claim
20 words
The arrangement of claim 1, wherein said filter means K exhibits multi-notch capability without requiring a filter for each notch.
Claim 5
Dependent Claim
18 words
The arrangement of claim 1, including a feedback loop means for correcting DC-offset from said filter means K.
Claim 6
Dependent Claim
24 words
The arrangement of claim 1, wherein said filter means K is operatively associated with a master clock means adapted to enhance the system stability.
Claim 7
Dependent Claim
25 words
The arrangement of claim 1 wherein said filter means K is arranged to minimize phase shift at a servo frequency where "open-loop gain crossover" occurs.
Claim 8
Dependent Claim
129 words
A disk drive positioning arrangement apt to be disturbed by resonant vibrations, this arrangement including a closed loop servo system with a "switched-capacitor" digital filter capability using filter means, which filter means is selected and arranged to attenuate resonant vibration and enhance the stability of the closed loop servo system for the disk drive positioning arrangement; said servo system comprising: a prescribed amplifier means A; an elliptical switched-capacitor digital filter means K, wherein the amplifier means A and the filter means K are connected in series to form a series circuit, which series circuit is connected between an input stage R and an output means C; and feed-back loop means for said filter means K, said feed-back loop means being adapted to correct DC-offset from said filter means K.
Claim 9
Dependent Claim
129 words
A disk drive positioning arrangement apt to be disturbed by resonant vibrations, this arrangement including a closed loop servo system with a "switched-capacitor" digital filter capability using filter means, which filter means is selected and arranged to attenuate resonant vibration and enhance the stability of the closed loop servo system for the disk drive positioning arrangement; said servo system comprising: a prescribed amplifier means A; an elliptical switched-capacitor digital filter means K, wherein the amplifier means A and the filter means K are connected in series to form a series circuit, which series circuit is connected between an input stage R and an output means C; and feed-back loop means for said filter means K, said feed-back loop means being adapted to correct DC-offset from said filter means K.
Claim 10
Dependent Claim
36 words
The arrangement of claim 7, wherein said filter means K has second-order low-pass outputs and second-order high-pass outputs, said second-order low-pass outputs being summed with said second-order high-pass outputs to form a fourth-order, elliptic, multi-notch filter.
Claim 11
Dependent Claim
20 words
The arrangement of claim 7, wherein said filter means K exhibits multi-notch capability without requiring a filter for each notch.
Claim 12
Dependent Claim
24 words
The arrangement of claim 7, wherein said filter means K is operatively associated with a master clock means adapted to enhance the system stability.
Claim 13
Dependent Claim
25 words
The arrangement of claim 7, wherein said filter means K is arranged to minimize phase shift at a servo frequency where "open-loop gain crossover" occurs.
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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) | 1994-07-15 | 1995-01-14 | 1995-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-15 | 1999-01-14 | 1999-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-15 | 2003-01-14 | 2003-07-16 | $7700.00 | Window Closed / Lapsed |