Patent EP0145962A2 successfully refreshed from Google Patents.
EP0145962A2
Expired / Lapsed
EP
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Digitally responsive method and apparatus for positioning a transducer of a storage apparatus
Assignee: Fujitsu Ltd
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Filing: 1984-11-14
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Granted: —
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Expires: 2004-11-14
Abstract
Abstract With a servo system for positioning a transducer of a rotatable storage apparatus over a servo tracks of a magnetic disk, a method for processing trains of positioning pulse signals is provided. With a fixed duration time, a reference voltage, changing with time, having a predetermined pattern is generated and compared with a train of the positioning pulse signals contained in the duration time. The magnitude of the positioning signals which varies with the displacement of the transducer from a guide path to be followed is given by counting the number of the positioning signals exceeding the reference voltage pattern. Thus, an error signal for the servo system is fed back in a digital form. The method causes cost reduction of the apparatus because of its simplicity and flexibility for the users' demand.
Inventors
- 👤 Yoshifumi Mizoshita
- 👤 Susumu Hasegawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 08:01
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/58; G11B5/596; G11B5/59633; G11B5/59655; G11B21/00; G11B21/02; G11B21/10; G11B21/106
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
182 words
A system for detecting the displacement of a first body moving relatively to a second body, with respect to a predetermined guide path (g) formed on said second body, comprising: a plurality of code members (A-1, A-2, ...; B-1, B-2, ...) arranged along said guide path (g), a positioning transducer (1) fixed to said first body, sensing said code members to generate a train of positioning signals (SAp, SAn; SBp, SBn) responding to the relative movement of said first body; a signal generator (12) generating a reference voltage changing with time, having a predetermined pattern within a given period; and a comparing means (14) to compare said train of positioning signals with said reference voltage, said positioning transducer generating a train of positioning signals by sensing said relatively moving code members, said reference voltage being generated within said period by said signal generator, said positioning signal train being compared with said reference voltage and sliced by said comparing means leaving remaining positioning signals, and the displacement of said first body from said guide path being determined by processing said remaining positioning signals.
Claim 2
Independent Claim
182 words
A system for detecting the displacement of a first body moving relatively to a second body, with respect to a predetermined guide path (g) formed on said second body, comprising: a plurality of code members (A-1, A-2, ...; B-1, B-2, ...) arranged along said guide path (g), a positioning transducer (1) fixed to said first body, sensing said code members to generate a train of positioning signals (SAp, SAn; SBp, SBn) responding to the relative movement of said first body; a signal generator (12) generating a reference voltage changing with time, having a predetermined pattern within a given period; and a comparing means (14) to compare said train of positioning signals with said reference voltage, said positioning transducer generating a train of positioning signals by sensing said relatively moving code members, said reference voltage being generated within said period by said signal generator, said positioning signal train being compared with said reference voltage and sliced by said comparing means leaving remaining positioning signals, and the displacement of said first body from said guide path being determined by processing said remaining positioning signals.
Claim 3
Dependent Claim
34 words
A system of claim 1, wherein said remaining positioning signals (SAp, SAn; SBp, SBn) are processed by counting the number of said remaining positioning signals to determine said displacement of said first body (1).
Claim 4
Dependent Claim
30 words
A system of claim 1, wherein said remaining positioning signals are processed by measuring the time duration of said remaining positioning signals to determine said displacement of said first body.
Claim 5
Dependent Claim
222 words
A digital responsive servo system for a rotatable storage apparatus comprising: a plurality of servo-tracks (2, 3; 101A, 101B) formed on a rotatable storage medium, having a guide path (g) comprising a boundary between two adjacent said servo tracks; a transducer (1, 100), positioned over said servo tracks following said guide path; a servo track configuration formed on said two adjacent servo tracks comprising two trains of magnetized domains on each said servo track, the magnetized orientations of said magnetized domains change alternately from one direction to the opposite direction to said one direction, forming a train of transistions having alternately changing polarities; a wave signal generator (12, 104) generating a repetitive reference voltage which changes with time, having a predetermined pattern with a given period; a comparing means (14; 106, 107) for comparing said reference voltage with said positioning signals; and a digital signal processing means (16, 17; 108, 109) for an output signal of said comparing means, said train of positioning signals being generated in said transducer by sensing transitions formed in said servo track configuration, thus generated positioning signals being compared with said reference voltage within said given period and slices by said comparing means, and remaining positioning signals being processed by a signal processing means so as to determine the displacement of said transducer from said guide path.
Claim 6
Dependent Claim
222 words
A digital responsive servo system for a rotatable storage apparatus comprising: a plurality of servo-tracks (2, 3; 101A, 101B) formed on a rotatable storage medium, having a guide path (g) comprising a boundary between two adjacent said servo tracks; a transducer (1, 100), positioned over said servo tracks following said guide path; a servo track configuration formed on said two adjacent servo tracks comprising two trains of magnetized domains on each said servo track, the magnetized orientations of said magnetized domains change alternately from one direction to the opposite direction to said one direction, forming a train of transistions having alternately changing polarities; a wave signal generator (12, 104) generating a repetitive reference voltage which changes with time, having a predetermined pattern with a given period; a comparing means (14; 106, 107) for comparing said reference voltage with said positioning signals; and a digital signal processing means (16, 17; 108, 109) for an output signal of said comparing means, said train of positioning signals being generated in said transducer by sensing transitions formed in said servo track configuration, thus generated positioning signals being compared with said reference voltage within said given period and slices by said comparing means, and remaining positioning signals being processed by a signal processing means so as to determine the displacement of said transducer from said guide path.
Claim 7
Dependent Claim
34 words
A digital responsive servo system for a rotatable storage apparatus of claim 4, wherein said remaining positioning signals are processed by counting its number with a counting means included in said signal processing means.
Claim 8
Dependent Claim
41 words
A digital responsive servo system for a rotatable storage apparatus of claim 4, wherein said remaining positioning signals are processed by measuring a time of duration of said remaining positioning signals by a clock counter included in said signal processing means.
References Cited (Backward Citations)
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