Magnetic head and multitrack transducer for perpendicular recording and method for fabricating
AssigneeCenstor Corp.
InventorHarold J. Hamilton
Life of this patent
Estimating the term…
Abstract
An improved recording and read head particularly suited for use with perpendicular recording techniques. The recording head can be fabricated either as a single head or as a multitrack array. If fabricated as a multitrack array, the head includes a plurality of main poles spaced closely to one another and a common long flux closing pole which completes a magnetic circuit between the main poles and the recording medium. Each main pole of the head array is individually addressable with a purpose of recording or reading by means of a flux gate arrangement. The flux gate may be utilized so that the head operates either in a conventional fashion by detecting the rate of change of induced flux or by detecting the magnitude of the induced flux.
Claims37
A transducer in cooperative relationship with a magnetic media for writing thereof and reading therefrom comprising:
- a magnetic path constructed for perpendicular recording and reproduction on and from the magnetic media,
- said magnetic path being constructed of a magnetic material having a high permeability and a low reluctance which facilitates the efficient passage of magnetic flux through said magnetic path, and
- a flux gate means coupled to said magnetic path for selectively creating a magnetic field in said magnetic path during either reading or writing which in effect increases the reluctance of the magnetic path to prevent the effective passage of magnetic flux therethrough whereby said magnetic path for perpendicular recording and reproduction can be closed and opened.
A transducer for perpendicular recording and reproduction on a magnetic media comprising:
- a magnetic element of a magnetic material having a high permeability and low reluctance, said magnetic element having a flux pole perpendicular to the magnetic media surface terminating in a pole tip adjacent the media, said pole defining a principal magnetic flux path therealong for recording on or reproduction from the media;
- means coupled to said magnetic element for creating a magnetic field in said pole transverse to said magnetic path to vary the reluctance of the principal magnetic path;
- and
- winding means coupled to the magnetic element to interact with the flux in said flux pole.
A perpendicular recording and reproduction head of the type having a flux closing body magnetically coupled to an elongated main pole confining a flux along its height and comprising:
- first means along the height of the main pole for varying the reluctance of the main pole to vary the main flux therein;
- and
- winding means coupled to the recording head to interact with the main flux in the main pole.
A transducer for magnetic recording and reproducing on and from a magnetic media comprising:
- a plurality of magnetic paths constructed for perpendicular recording and reproduction on the magnetic media,
- said magnetic paths being constructed of a magnetic material and having a high permeability and low reluctance which facilitates the efficient passage of magnetic flux through said magnetic paths;
- a switching means coupled to each of said magnetic paths for selectively switching any of said magnetic paths from a low reluctance to a high reluctance;
- and
- a continuous conductor means in proximity to a plurality of said magnetic paths for sensing the magnetic flux passing through said plurality of magnetic paths.
A magnetic head for use in perpendicular recording on a magnetic medium functioning as part of the flux return path comprising:
- a main magnetic pole lying along a perpendicular recording axis and forming a closed path about the axis, the main magnetic pole having a pole tip adjacent said magnetic medium;
- conductor means within the closed path for magnetizing the main magnetic pole in the direction of the closed path with a gating current;
- and
- means including winding means for interacting with magnetic flux variations along the perpendicular recording axis in a flux path including the magnetic medium.
A magnetic head suitable for use in perpendicular recording and reproduction, comprising:
- a main pole of high permeability material;
- a flux closing pole of high permeability material;
- a bridge member connecting the main pole to the flux closing pole;
- said main pole, flux closing pole and bridge member forming part of a magnetic circuit;
- a sense winding coupled to said magnetic circuit;
- and
- a flux gate means for selectively saturating at least a portion of said magnetic circuit either during recording or reproduction whereby flux passing through the main pole may be effectively coupled and decoupled to and from said sense winding.
A multitrack magnetic head for recording and reproducing on a magnetic medium comprising:
- a plurality of main poles spaced apart and in a given plane lying perpendicular to;
- flux closing means magnetically coupled to the main poles at a spacing from said magnetic medium;
- winding means coupled to the magnetic circuit formed by the main poles and the flux closing means;
- and
- means coupled to the main poles for varying the reluctance thereof in selectable combinations, whereby only certain pole means function as a transducer at any time.
A multitrack magnetic head suitable for use in perpendicular recording, comprising:
- a wafer of high permeability material having an end surface, a top surface and a bottom surface adapted to be positioned adjacent a magnetic medium;
- said wafer forming a flux closing pole;
- a plurality of main poles formed on said end surface and extending to a position adjacent said magnetic medium;
- said main poles being magnetically connected to one portion of the flux closing pole removed from the magnetic medium and being magnetically isolated from said flux closing pole adjacent said magnetic medium;
- said main poles and flux closing pole adapted to form a plurality of magnetic circuits when positioned adjacent said medium;
- a sense conductor coupled to said magnetic circuits;
- and
- a flux gate means for each of said main poles for selectively saturating at least a portion of each of said magnetic circuits.
A magnetic head suitable for use in perpendicular recording, comprising:
- a main pole of high permeability material;
- a flux closing pole of high permeability material;
- a bridge member connecting the main pole to the flux closing pole;
- said main pole and flux closing pole having lower surfaces which are substantially coplanar, the cross-sectional length of the lower surface of the flux closing pole being substantially greater than that of the main pole;
- a sense winding located between the main pole and flux closing pole;
- and
- a flux gate conductor coupled to the main pole for providing a saturating current to the main pole.
A magnetic head suitable for use in perpendicular recording, comprising:
- a wafer of high permeability material, said wafer including a front surface and top and bottom surfaces;
- wherein the bottom surface of the wafer defines a flux closing pole,
- a sense winding comprising at least one layer of a conductive material extending laterally across the front surface of the wafer and covering a lower portion of said front surface;
- at least a pair of winding leads, each comprising a layer of conductive material connected to said sense winding and extending rearward from the front surface along a surface of the wafer;
- a layer of insulation insulating the sense winding from the main pole;
- a flux gate main pole located on the front surface of said wafer, said flux gated main pole comprising a first layer of high permeability material extending substantially from the top to bottom surfaces of the wafer, a layer of electrically conductive material overlaying the first layer and a second layer of high permeability material overlaying the conductive layer and extending to join said first layer, said first and second layers of high permeability material defining the main pole, wherein the main pole is isolated from the sense winding by said insulation layer;
- and
- flux gate connector conductors electrically connected to the flux gate main pole, and electrically isolated from the winding leads.
A multitrack magnetic head suitable for use in perpendicular recording, comprising:
- a wafer of high permeability material, said wafer including a front surface and top and bottom surfaces;
- the bottom surface of said wafer defining a common flux closing pole,
- a sense winding comprising at least one layer of a conductive material extending laterally across the front surface of the wafer, and covering a lower portion of said front surface;
- at least a pair of winding leads, each comprising a layer of conductive material connected to said sense winding;
- a layer of insulation insulating the sense winding from the main pole;
- a plurality of spaced flux gated main poles located on the front surface of the wafer, each of said main poles comprising a first layer of high permeability material extending substantially from the top to bottom surface of the wafer, a layer of conductive material overlaying the first layer of high permeability material, and a second layer of high permeability material overlaying the conductive layer and extending to join said first layer, said first and second layers defining the main pole, wherein the main pole is isolated from the sense winding by said insulation layer;
- and
- a plurality of flux gate connector conductors of conductive material overlaying one of the surfaces of the wafer, one each of said flux gate conductors being connected to said conductive layer of the main pole flux gate;
- and
- a bus conductor of conductive material connecting said conductive layer of each main pole in the vicinity of the bottom surface.
A perpendicular recording head for recording on a magnetic medium comprising a magnetic circuit including a main pole, a flux closing body coupled to said main pole and said magnetic medium;
- said main pole comprising an elongated body having a height, a length and a width, said length generally aligned with the direction of the movement of the recording medium, said width generally extending in a direction across said recording medium and said height generally extending at an angle to the surface of said recording medium;
- said main pole having a height to length ratio greater than twenty to one;
- and means within and along the height of said main pole for varying the reluctance of the main pole substantially independent of the flux in the magnetic circuit.
Dependencies are inferred from the claim text.