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US4935830A Expired / Lapsed US ⏱️ 0.0 years remaining

Electro-magnetic shield structure for shielding a servo magnetic head of a magnetic disk storage device

Assignee: Fujitsu Ltd
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Filing: 1988-03-15
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Granted: 1990-06-19
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Expires: 2008-03-15
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Abstract

Abstract A magnetic disk storage device having a magnetic shield for shielding a magnetic servo-head from noise generated by an adjacent data-head during a write operation when both magnetic heads are arranged back-to-back in a space between two magnetic disks stacked co-axially. The shield plate is secured to an inner surface of a base portion of a housing of the device, thus avoiding an increase in the weight and moment of inertia of moving members of a head positioner.

Inventors

  • 👤 Sinzi Hiraoka
  • 👤 Kazuo Matsuda
  • 👤 Takeshi Ohyama

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 12:36
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/40; G11B5/10; G11B5/11; G11B5/48; G11B5/54; G11B5/55; G11B5/5521; G11B5/58

Claims Analysis

Total Claims: 21
Claim 1
Independent Claim 211 words
A magnetic disk storage device comprising: a housing means having a base portion for housing said magnetic disk storage device; a plurality of magnetic disks being co-axially stacked and spaced apart from each other, and rotatable around an axis of rotation, said plurality of magnetic disks including a first magnetic disk having a first surface and a second magnetic disk having a second surface such that said first surface and said second surface are spaced apart and face each other; a plurality of magnetic heads respectively positioned adjacent corresponding ones of said plurality of magnetic disks, said magnetic heads including magnetic data-head means, positioned to face said first surface, for generating a magnetic flux so as to write data to said first surface and for reading data from said first surface, and including magnetic servo-head means, positioned to face said second surface, for reading servo information stored on said second surface; and shield means, positioned between said magnetic data-head means and said magnetic servo-head means and being secured to said base portion of said housing means, for preventing erroneous operation of said servo-head means by electromagnetically shielding said servo-head from the magnetic flux emanating from said data-head and for inhibiting the magnetic flux emanating from said data-head from reaching said servo-head.
Claim 2
Dependent Claim 211 words
A magnetic disk storage device comprising: a housing means having a base portion for housing said magnetic disk storage device; a plurality of magnetic disks being co-axially stacked and spaced apart from each other, and rotatable around an axis of rotation, said plurality of magnetic disks including a first magnetic disk having a first surface and a second magnetic disk having a second surface such that said first surface and said second surface are spaced apart and face each other; a plurality of magnetic heads respectively positioned adjacent corresponding ones of said plurality of magnetic disks, said magnetic heads including magnetic data-head means, positioned to face said first surface, for generating a magnetic flux so as to write data to said first surface and for reading data from said first surface, and including magnetic servo-head means, positioned to face said second surface, for reading servo information stored on said second surface; and shield means, positioned between said magnetic data-head means and said magnetic servo-head means and being secured to said base portion of said housing means, for preventing erroneous operation of said servo-head means by electromagnetically shielding said servo-head from the magnetic flux emanating from said data-head and for inhibiting the magnetic flux emanating from said data-head from reaching said servo-head.
Claim 3
Dependent Claim 31 words
A magnetic disk storage device according to claim 1, wherein shield means is constructed of a material selected from a group consisting of ferrite, an iron-nickel alloy, and magnetic stainless steel.
Claim 4
Dependent Claim 35 words
A magnetic disk storage device according to claim 1, further comprising magnetic head positioner means for positioning said magnetic data-head means and said magnetic servo-head means with respect to said first and second disk surfaces.
Claim 5
Dependent Claim 35 words
A magnetic disk storage device according to claim 3, wherein said magnetic head positioner means comprises swinging type positioner means for positioning said magnetic servo-head means and said magnetic data-head means along an arc-shaped orbit.
Claim 6
Dependent Claim 99 words
A magnetic disk storage device according to claim 4, wherein said magnetic head positioner means comprises: a supporting member comprising a suspension member flexibly suspending said magnetic servo-head means and said magnetic data-head means at a first end of said suspension member; and a rigid supporting arm being fixed to a second end of said suspension member being opposite said first end, so that a longitudinal axis of said suspension member is aligned in line with a straight line running from a center of said magnetic data-head means to an axis of rotation of said magnetic head positioner means.
Claim 7
Dependent Claim 32 words
A magnetic disk storage device according to claim 3, wherein said head positioner means comprises linear type positioning means for positioning said magnetic servo-head and said magnetic data-head along a straight line.
Claim 8
Dependent Claim 82 words
A magnetic disk storage device according to claim 6, wherein said magnetic head positioner means comprises: a supporting member comprising a suspension member flexibly suspending said magnetic servo-head means and said magnetic data-head means at a first end of said suspension member; and a rigid supporting arm being fixed at a second end of said suspension member opposite said first end, so that a longitudinal axis of said suspension member is in a radial direction of said first and second magnetic disks.
Claim 9
Dependent Claim 26 words
A magnetic disk storage device according to claim 5 further comprising n magnetic data-head means respectively positioned at n different radii, wherein n denotes an integer.
Claim 10
Dependent Claim 26 words
A magnetic disk storage device according to claim 7 further comprising n magnetic data-head means respectively positioned at n different radii, wherein n denotes an integer.
Claim 11
Dependent Claim 17 words
A magnetic disk storage device according to claim 8, wherein said integer n is equal to 2.
Claim 12
Dependent Claim 17 words
A magnetic disk storage device according to claim 9, wherein said integer n is equal to 2.
Claim 13
Dependent Claim 59 words
A magnetic disk storage device according to claim 10, wherein said suspension member includes: a spring member having a base portion and two branches extending from said base portion, each of said branches receptively supporting one of: said n magnetic data-head means and said magnetic servo-head means, said spring member comprising a single piece of a thin resilient material.
Claim 14
Dependent Claim 59 words
A magnetic disk storage device according to claim 11, wherein said suspension member includes: a spring member having a base portion and two branches extending from said base portion, each of said branches respectively supporting one of: said n magnetic data-head means and said magnetic servo-head means, said spring member comprising a single piece of a thin resilient material.
Claim 15
Dependent Claim 26 words
A magnetic disk storage device according to claim 1, wherein at least two of said magnetic data-head means are respectively positioned at least two difference radii.
Claim 16
Dependent Claim 47 words
A magnetic disk storage device according to claim 14, further comprising: a spring member comprising a single piece of a thin resilient material and having a base portion and two branches extending from said base portion, said branches respectively supporting said at least two magnetic data-head means.
Claim 17
Dependent Claim 39 words
A magnetic disk storage device according to claim 1, further comprising: swing type positioner means for positioning said magnetic servo-head means and said magnetic data-head means along and arc-shaped orbit with respect to said first and second disk surfaces.
Claim 18
Dependent Claim 37 words
A magnetic disk storage device according to claim 1, further comprising: linear type positioning means for positioning said magnetic servo-head and said magnetic data-head along a straight line with respect to said first and second disk surfaces.
Claim 19
Dependent Claim 242 words
A magnetic disk storage device comprising: a housing means having a base portion for housing said magnetic disk storage device; a first magnetic disk and a second magnetic disk being co-axially stacked and spaced apart from each other, and rotatable around an axis of rotation, said first magnetic disk having a first surface and said second magnetic disk having a second surface such that said first surface and said second surface are spaced apart and face each other; at least two magnetic data-head means, positioned to face said first surface and respectively positioned at different radii, for writing to and reading from said first surface; magnetic servo-head means, positioned to face said second surface, for reading servo information stored on said second surface; shield means, positioned between said magnetic data-head means and said magnetic servo-head means, and being secured to said base portion of said housing means, for electromagnetically shield said servo-head from magnetic flux emanating from said data-head and for inhibiting magnetic flux emanating from said data-head from reaching said servo-head; magnetic head positioner means for positioning said magnetic data-head means and said magnetic servo-head means with respect to said first and second disk surfaces; a supporting member comprising a suspension member flexibly suspending said magnetic servo-head means and said magnetic data-head means at a first end of said suspension member; and a rigid supporting arm being fixed to a second end of said suspension member being opposite said first end.
Claim 20
Dependent Claim 242 words
A magnetic disk storage device comprising: a housing means having a base portion for housing said magnetic disk storage device; a first magnetic disk and a second magnetic disk being co-axially stacked and spaced apart from each other, and rotatable around an axis of rotation, said first magnetic disk having a first surface and said second magnetic disk having a second surface such that said first surface and said second surface are spaced apart and face each other; at least two magnetic data-head means, positioned to face said first surface and respectively positioned at different radii, for writing to and reading from said first surface; magnetic servo-head means, positioned to face said second surface, for reading servo information stored on said second surface; shield means, positioned between said magnetic data-head means and said magnetic servo-head means, and being secured to said base portion of said housing means, for electromagnetically shield said servo-head from magnetic flux emanating from said data-head and for inhibiting magnetic flux emanating from said data-head from reaching said servo-head; magnetic head positioner means for positioning said magnetic data-head means and said magnetic servo-head means with respect to said first and second disk surfaces; a supporting member comprising a suspension member flexibly suspending said magnetic servo-head means and said magnetic data-head means at a first end of said suspension member; and a rigid supporting arm being fixed to a second end of said suspension member being opposite said first end.
Claim 21
Dependent Claim 58 words
A magnetic disk storage device according to claim 18, wherein said suspension member includes: a spring member having a base portion and two branches extending from said base portion, each said branches respectively supporting one of: said n magnetic data-head means and said magnetic servo-head means, said spring member comprising a single piece of a thin resilient material.

References Cited (Backward Citations)

US4346416A Cited
US4402025A Cited
JPS5817515A Cited
US4571649A Cited
JPS60136024A Cited
JPS60140524A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-06-18 1993-12-18 1994-06-19 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-06-18 1997-12-18 1998-06-19 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-06-18 2001-12-18 2002-06-19 $7700.00 Window Closed / Lapsed

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