US3686649A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic positioning mechanism with trapezoidal head
Assignee: Unisys Corp
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Filing: 1970-11-18
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Granted: 1972-08-22
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Expires: 1990-11-18
Abstract
Abstract Method and apparatus for positioning a magnetic transducer adjacent the recording medium on a face of a magnetic recording disk is provided. Information is recorded on the disk in one or more information zones with an information head arranged adjacent each of these zones. A control zone provided on a face of the disk is adjacent a control transducer which is coupled to the information heads. The heads are also coupled to a mechanical position controller for positioning the heads radially on the disk. Recorded in the control zone are a plurality of magnetic transitions in lines extending at an angle relative to a disk radius. In a short segment, neglecting disk curvature, the magnetic regions bounded by the transition lines are in the form of interlaced trapezoids, and the recording medium moves relative to the control transducer in a direction parallel to the parallel sides of the trapezoids. The time required for the magnetic transducer to travel from one magnetic transition to the next is therefore a function of the transducer''s position between the parallel sides of the trapezoid, that is, the radial position relative to the disk. The time interval so measured is compared with a reference time signal to generate an error signal which is fed back to the mechanical position control so that the magnetic transducers are positioned in the desired position.
Inventors
- 👤 Michael I Behr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:48
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/54; G11B5/55; G11B5/5521; G11B5/5526; G05; G05D; G05D3/00; G05D3/12; G05D3/14; G05D3/18
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
160 words
A combination comprising: an information magnetic transducer head; a magnetic recording medium on a face of a rotatable disk movable past the transducer head and having a circumferentially extending information zone; a circumferentially extending control zone on the magnetic recording medium concentric with the information zone and radially spaced therefrom, said control zone having a plurality of magnetic transitions arranged diagonally relative to the direction of relative movement of the recording medium past the information head; a control magnetic transducer mechanically linked to the information head; aNd means for positioning the control transducer in a radial direction in response to sensing of the magnetic transitions by the control transducer; and wherein the magnetic transitions comprise: a first polarity of magnetic transition in lines skewed relative to disk radii at an angle phi clockwise from the respective radius; and a second polarity of magnetic transition in lines skewed relative to disk radii at an angle phi counterclockwise from the respective radius.
Claim 2
Dependent Claim
160 words
A combination comprising: an information magnetic transducer head; a magnetic recording medium on a face of a rotatable disk movable past the transducer head and having a circumferentially extending information zone; a circumferentially extending control zone on the magnetic recording medium concentric with the information zone and radially spaced therefrom, said control zone having a plurality of magnetic transitions arranged diagonally relative to the direction of relative movement of the recording medium past the information head; a control magnetic transducer mechanically linked to the information head; aNd means for positioning the control transducer in a radial direction in response to sensing of the magnetic transitions by the control transducer; and wherein the magnetic transitions comprise: a first polarity of magnetic transition in lines skewed relative to disk radii at an angle phi clockwise from the respective radius; and a second polarity of magnetic transition in lines skewed relative to disk radii at an angle phi counterclockwise from the respective radius.
Claim 3
Dependent Claim
207 words
A combination comprising: an information magnetic transducer head; a magnetic recording medium on a face of a rotatable disk movable past the transducer head and having a circumferentially extending information zone; a circumferentially extending control zone on the magnetic recording medium concentric with the information zone, said control zone having a plurality of magnetic transitions arranged diagonally relative to the direction of relative movement of the recording medium past the information head, said magnetic transitions comprising: a first polarity of magnetic transition in lines skewed relative to disk radii at an angle phi clockwise from the respective radius, and a second polarity of magnetic transition in lines skewed relative to disk radii at an angle phi counterclockwise from the respective radius; a control magnetic transducer mechanically linked to the information head; means for positioning the control transducer in a direction transverse to the direction of relative movement in response to sensing of the magnetic transitions by the control transducer; means for generating a reference signal; means for comparing the time interval between adjacent magnetic transitions as sensed by the control transducer with the reference signal for producing an error signal; and means for positioning the control transducer in a radial direction in response to the error signal.
Claim 4
Dependent Claim
207 words
A combination comprising: an information magnetic transducer head; a magnetic recording medium on a face of a rotatable disk movable past the transducer head and having a circumferentially extending information zone; a circumferentially extending control zone on the magnetic recording medium concentric with the information zone, said control zone having a plurality of magnetic transitions arranged diagonally relative to the direction of relative movement of the recording medium past the information head, said magnetic transitions comprising: a first polarity of magnetic transition in lines skewed relative to disk radii at an angle phi clockwise from the respective radius, and a second polarity of magnetic transition in lines skewed relative to disk radii at an angle phi counterclockwise from the respective radius; a control magnetic transducer mechanically linked to the information head; means for positioning the control transducer in a direction transverse to the direction of relative movement in response to sensing of the magnetic transitions by the control transducer; means for generating a reference signal; means for comparing the time interval between adjacent magnetic transitions as sensed by the control transducer with the reference signal for producing an error signal; and means for positioning the control transducer in a radial direction in response to the error signal.
Claim 5
Dependent Claim
162 words
A magnetic memory system comprising: a rotatable magnetic memory disk having a magnetic recording medium on a face thereof; a circumferentially extending information zone on the recording medium for recording information in the form of magnetic signals; a circumferentially extending control zone on the magnetic medium concentric with the information zone, said control zone including a plurality of magnetic transitions arranged in lines each at a known angle to a radius of the disk, the lines alternately converging and diverging in a direction extending radially outwardly on the disk; a control magnetic transducer adjacent the control zone on the disk for sensing the magnetic transitions; an information magnetic transducer connected to the control transducer and adjacent the information zone on the disk for recording and reading magnetic information signals; means connected to the information an control transducers for positioning the transducers radially of the disk; and means for controlling the means for positioning in response to signals sensed by the control transducer.
Claim 6
Dependent Claim
162 words
A magnetic memory system comprising: a rotatable magnetic memory disk having a magnetic recording medium on a face thereof; a circumferentially extending information zone on the recording medium for recording information in the form of magnetic signals; a circumferentially extending control zone on the magnetic medium concentric with the information zone, said control zone including a plurality of magnetic transitions arranged in lines each at a known angle to a radius of the disk, the lines alternately converging and diverging in a direction extending radially outwardly on the disk; a control magnetic transducer adjacent the control zone on the disk for sensing the magnetic transitions; an information magnetic transducer connected to the control transducer and adjacent the information zone on the disk for recording and reading magnetic information signals; means connected to the information an control transducers for positioning the transducers radially of the disk; and means for controlling the means for positioning in response to signals sensed by the control transducer.
Claim 7
Dependent Claim
58 words
A memory system as defined in claim 3 wherein the means for controlling comprises: means for generating a reference signal representative of a desired control transducer position; means for generating a control signal from the control transducer; and means for comparing the control signal and reference signal and applying the resultant error signal to the means for positioning.
Claim 8
Dependent Claim
58 words
A memory system as defined in claim 4 wherein the magnetic transitions comprise: a first polarity of magnetic transition in lines skewed relative to disk radii at an angle phi clockwise from the respective radius; and a second polarity of magnetic transition in lines skewed relative to disk radii at an angle phi counter-clockwise from the respective radius.
Claim 9
Dependent Claim
260 words
A magnetic memory system comprising: a rotatable magnetic memory disk having a magnetic recording medium on a face thereof; a circumferentially extending inforMation zone on the recording medium for recording information in the form of magnetic signals; a circumferentially extending control zone on the magnetic medium concentric with the information zone, said control zone including a plurality of magnetic transitions arranged in lines each at a known angle to a radius of the disk, the lines alternately converging and diverging in a direction extending radially outwardly on the disk; a control magnetic transducer adjacent the control zone on the disk for sensing the magnetic transitions; an information magnetic transducer connected to the control transducer and adjacent the information zone on the disk for recording and reading magnetic information signals; means connected to the information and control transducers for positioning the transducers radially of the disk; means for generating a reference signal representative of a desired control transducer position; means for generating a control signal from the control transducer; and means for comparing the control signal and reference signal and applying the resultant error signal to the means for positioning; and wherein the magnetic transitions comprise: a first pair of magnetic transitions of opposite polarity spaced apart in parallel lines, both lines being skewed relative to a disk radius at an angle phi clockwise from the respective radius; and a second pair of magnetic transitions of opposite polarity spaced apart in parallel lines, both lines being skewed relative to a disk radius at an angle phi counter-clockwise from the respective radius.
Claim 10
Dependent Claim
260 words
A magnetic memory system comprising: a rotatable magnetic memory disk having a magnetic recording medium on a face thereof; a circumferentially extending inforMation zone on the recording medium for recording information in the form of magnetic signals; a circumferentially extending control zone on the magnetic medium concentric with the information zone, said control zone including a plurality of magnetic transitions arranged in lines each at a known angle to a radius of the disk, the lines alternately converging and diverging in a direction extending radially outwardly on the disk; a control magnetic transducer adjacent the control zone on the disk for sensing the magnetic transitions; an information magnetic transducer connected to the control transducer and adjacent the information zone on the disk for recording and reading magnetic information signals; means connected to the information and control transducers for positioning the transducers radially of the disk; means for generating a reference signal representative of a desired control transducer position; means for generating a control signal from the control transducer; and means for comparing the control signal and reference signal and applying the resultant error signal to the means for positioning; and wherein the magnetic transitions comprise: a first pair of magnetic transitions of opposite polarity spaced apart in parallel lines, both lines being skewed relative to a disk radius at an angle phi clockwise from the respective radius; and a second pair of magnetic transitions of opposite polarity spaced apart in parallel lines, both lines being skewed relative to a disk radius at an angle phi counter-clockwise from the respective radius.
Claim 11
Independent Claim
115 words
A method for positioning an information head adjacent a moving magnetic recording medium in a direction transverse to direction of relative movement therebetween comprising: recording alternate regions of first and second magnetic polarity on the magnetic recording medium, the lines of magnetic transition between successive regions being diagonal to the direction of relative movement; coupling the information head to a control transducer so that the information head position is directly responsive to control transducer position; sensing the time interval between a pair of the magnetic transitions with the control transducer; comparing the sensed time interval with a reference signal for generating a comparison signal; and positioning the control transducer in response to the comparison signal.
Claim 12
Independent Claim
115 words
A method for positioning an information head adjacent a moving magnetic recording medium in a direction transverse to direction of relative movement therebetween comprising: recording alternate regions of first and second magnetic polarity on the magnetic recording medium, the lines of magnetic transition between successive regions being diagonal to the direction of relative movement; coupling the information head to a control transducer so that the information head position is directly responsive to control transducer position; sensing the time interval between a pair of the magnetic transitions with the control transducer; comparing the sensed time interval with a reference signal for generating a comparison signal; and positioning the control transducer in response to the comparison signal.
Claim 13
Independent Claim
80 words
A method for recording a magnetic control signal comprising: arranging a magnetic recording transducer having a pair of pole pieces separated by a trapezoidal gap free of magnetic material adjacent a magnetic recording medium magnetized with one polarity; passing the transducer along a control track on the recording medium in a direction substantially parallel to the base of the trapezoidal gap; and producing interlaced trapezoidal areas of opposite magnetic polarity in the control track by intermittently pulsing the magnetic transducer.
Claim 14
Independent Claim
80 words
A method for recording a magnetic control signal comprising: arranging a magnetic recording transducer having a pair of pole pieces separated by a trapezoidal gap free of magnetic material adjacent a magnetic recording medium magnetized with one polarity; passing the transducer along a control track on the recording medium in a direction substantially parallel to the base of the trapezoidal gap; and producing interlaced trapezoidal areas of opposite magnetic polarity in the control track by intermittently pulsing the magnetic transducer.
Claim 15
Independent Claim
99 words
A method for recording a magnetic control signal comprising: arranging a magnetic recording transducer having a pair of pole pieces separated by a trapezoidal gap and having a trapezoidal magnetic shunt arranged in the gap and spaced apart from the edges thereof, adjacent a magnetic recording medium magnetized with one polarity; passing the transducer along a control track on the recording medium in a direction substantially parallel to the base of the trapezoidal gap; and producing interlaced trapezoidal areas of like polarity separated by strips of opposite magnetic polarity in the control track by intermittently pulsing the magnetic transducer.
Claim 16
Independent Claim
99 words
A method for recording a magnetic control signal comprising: arranging a magnetic recording transducer having a pair of pole pieces separated by a trapezoidal gap and having a trapezoidal magnetic shunt arranged in the gap and spaced apart from the edges thereof, adjacent a magnetic recording medium magnetized with one polarity; passing the transducer along a control track on the recording medium in a direction substantially parallel to the base of the trapezoidal gap; and producing interlaced trapezoidal areas of like polarity separated by strips of opposite magnetic polarity in the control track by intermittently pulsing the magnetic transducer.
Claim 17
Dependent Claim
69 words
A magnetic recording transducer comprising: first and second opposed magnetic pole pieces; a trapezoidal magnetic gap between the first and second pole pieces; a trapezoidal magnetic shunt positioned in the trapezoidal gap and spaced apart from the first and second pole pieces, respectively, for defining a pair of diverging magnetic gaps therebEtween; and means for intermittently inducing a magnetic flux in the pole pieces and across the trapezoidal gap.
Claim 18
Dependent Claim
69 words
A magnetic recording transducer comprising: first and second opposed magnetic pole pieces; a trapezoidal magnetic gap between the first and second pole pieces; a trapezoidal magnetic shunt positioned in the trapezoidal gap and spaced apart from the first and second pole pieces, respectively, for defining a pair of diverging magnetic gaps therebEtween; and means for intermittently inducing a magnetic flux in the pole pieces and across the trapezoidal gap.
Claim 19
Dependent Claim
116 words
A magnetic memory system comprising: a rotatable magnetic memory disk having a magnetic recording medium on a face thereof; a circumferentially extending information zone on the recording medium for recording information in the form of magnetic signals; a circumferentially extending control zone on the magnetic medium concentric with the information zone, said control zone including a plurality of magnetic transitions arranged in lines each at a known angle to a radius of the disk, the lines alternately converging and diverging in a direction extending radially outwardly on the disk; and means for positioning a magnetic transducer in a radial direction adjacent the disk in response to the time interval between a pair of the magnetic transitions.
Claim 20
Dependent Claim
116 words
A magnetic memory system comprising: a rotatable magnetic memory disk having a magnetic recording medium on a face thereof; a circumferentially extending information zone on the recording medium for recording information in the form of magnetic signals; a circumferentially extending control zone on the magnetic medium concentric with the information zone, said control zone including a plurality of magnetic transitions arranged in lines each at a known angle to a radius of the disk, the lines alternately converging and diverging in a direction extending radially outwardly on the disk; and means for positioning a magnetic transducer in a radial direction adjacent the disk in response to the time interval between a pair of the magnetic transitions.
Claim 21
Dependent Claim
38 words
A magnetic memory system as defined in claim 11 wherein each of the magnetic transitions is between a first substantially trapezoidal region having a first magnetic polarity and a second substantially trapezoidal region having a second magnetic polarity.
Claim 22
Dependent Claim
35 words
A magnetic memory system as defined in claim 11 wherein each of the lines comprises a pair of spaced apart parallel magnetic transitions between a first polarity, a second polarity and the first polarity, respectively.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-22 | 1976-02-21 | 1976-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-22 | 1980-02-21 | 1980-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-22 | 1984-02-21 | 1984-08-22 | $7700.00 | Window Closed / Lapsed |