Patents by Inventor Jacobus J. M. Ruigrok

Jacobus J. M. Ruigrok has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6747854
    Abstract: Multi-channel magnetic head having a high channel density, provided with a head face (1) which extends in a first direction (I) in which a record carrier is relatively movable with respect to said magnetic head, and in a second direction (II) transverse to the first direction. The magnetic head has a structure of layers which, viewed in the first direction, are situated one on top of the other and extend substantially in the second direction and in a third direction (III) transverse to the first and the second direction. Viewed in the second direction, adjacent magnetoresistive sensors (S1, S2, S3) are distinguishable in the structure, each comprising a magnetoresistive measuring element (5), a first magnetic element (7) and a second magnetic element (9).
    Type: Grant
    Filed: January 12, 1998
    Date of Patent: June 8, 2004
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Jacobus J. M. Ruigrok, Gerardus H. J. Somers
  • Patent number: 6486662
    Abstract: A magnetic field sensor comprises a transducer element, which: transducer element is a Spin Tunnel Junction, comprising a first and second magnetic layer which are sandwiched about an interposed electrical insulator layer; the sensor comprises a yoke having two arms; and the first magnetic layer is in direct contact with a first portion of a first arm of the yoke.
    Type: Grant
    Filed: October 26, 1998
    Date of Patent: November 26, 2002
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Jacobus J. M. Ruigrok, Reinder Coehoorn, Pieter J. Van Der Zaag
  • Patent number: 6278588
    Abstract: A magnetoresistive magnetic field sensor comprises a bilayer with a first soft magnetic layer and in direct contact therewith a second soft magnetic layer. The layers are exchange coupled to one another. The second soft magnetic layer is located below, on or in the first soft magnetic layer in a meandering, spiraling or suchlike structure. The electrical resistivity of the first soft magnetic layer is higher than that of the second soft magnetic layer, while the difference in electrical resistivity between both soft magnetic layers is at least a factor of 10, preferably a factor of 100. The magnetoresistive magnetic field sensor is applied in a magnetic read head device for a recording information system.
    Type: Grant
    Filed: November 1, 1999
    Date of Patent: August 21, 2001
    Assignee: U.S. Philips Corporation
    Inventor: Jacobus J. M. Ruigrok
  • Patent number: 6266217
    Abstract: a magnetic head with a head face includes a multilayer structure with a flux guide, a magnetoresistive sensor, and an intermediate layer present between the flux guide and the sensor. The intermediate layer includes an anti-ferromagnetic oxide which insulates the sensor from the flux guide and also magnetically biases the sensor.
    Type: Grant
    Filed: March 1, 1999
    Date of Patent: July 24, 2001
    Assignee: U.S. Philips Corporation
    Inventors: Jacobus J. M. Ruigrok, Pieter J. Van Der Zaag
  • Patent number: 6238731
    Abstract: Thin-film magnetic head having a head face (103) and comprising a magnetoresistive element (109) oriented transversely to the head face and a flux-guiding element (107) of a magnetically permeable material terminating in the head face. A peripheral area (109a) of the magnetoresistive element extending parallel to the head face is present opposite the flux-guiding element for forming a magnetic connection between the magnetoresistive element and the flux-guiding element. The flux-guiding element and the peripheral area of the magnetoresistive element constitute a common magnetic contact face (111), while the magnetically permeable material of the flux-guiding element is electrically insulating.
    Type: Grant
    Filed: September 7, 1999
    Date of Patent: May 29, 2001
    Assignee: U.S. Philips Corporation
    Inventors: Jacobus J. M. Ruigrok, Pieter J. Van Der Zaag, Wiepke Folkerts, Lambertus Postma, Ronald M. Wolf, Johannes F. M. Cillessen
  • Patent number: 6233126
    Abstract: Thin film magnetic head has magnetoresistive element (23) and flux-guiding elements (117a,117b) of a material having a relatively high magnetic permeability, and an intermediate layer between the magnetoresistive element and the flux-guiding elements, the intermediate layer (21) being electrically insulating, and having a relatively low magnetic permeability of between 1.1 and 25. The low permeability intermediate layer increases the magnetic flux between the magnetoresistive element and the flux-guiding elements, and thereby improves the efficiency of the magnetic head.
    Type: Grant
    Filed: August 15, 1996
    Date of Patent: May 15, 2001
    Assignee: U.S. Philips Corporation
    Inventors: Pieter J. Van der Zaag, Jacobus J. M. Ruigrok, Harald Van Kampen
  • Patent number: 6205007
    Abstract: Thin-film magnetic head having a head face (103) and comprising a magnetoresistive element (109) oriented transversely to the head face and a flux-guiding element (107) of a magnetically permeable material terminating in the head face. A peripheral area (109a) of the magnetoresistive element extending parallel to the head face is present opposite the flux-guiding element for forming a magnetic connection between the magnetoresistive element and the flux-guiding element. The flux-guiding element and the peripheral area of the magnetoresistive element constitute a common magnetic contact face (111), while the magnetically permeable material of the flux-guiding element is electrically insulating.
    Type: Grant
    Filed: November 22, 1993
    Date of Patent: March 20, 2001
    Assignee: U.S. Philips Corporation
    Inventors: Jacobus J. M. Ruigrok, Pieter J. Van Der Zaag, Wiepke Folkerts, Lambertus Postma, Ronald M. Wolf, Johannes F. M. Cillessen
  • Patent number: 6110539
    Abstract: A method for creating a magnetically permeable film on a substrate surface by deposition of successive layers of a magnetic material, during deposition of each layer a magnetic field being provided near said surface having a field direction substantially parallel to the surface. In order to tune the permeability of the magnetic material the method builds up the magnetically permeable film by forming each layer by depositing a ferromagnetic material to a thickness maximally corresponding to substantially ##EQU1## where L.sub.ex is equal to ##EQU2## with A being the exchange constant of the ferromagnetic material and K.sub.u being the uniaxial anisotropy constant, and changing the magnetic field direction during formation of said layer by an angle other than substantially 180.degree..
    Type: Grant
    Filed: January 27, 1999
    Date of Patent: August 29, 2000
    Assignee: U.S. Philips Corporation
    Inventors: Pascal J.H. Bloemen, Jacobus J.M. Ruigrok
  • Patent number: 5984745
    Abstract: An element of an apparatus is magnetized so as to generate a magnetic field pattern around the element. To achieve this, use is made of a magnetizing coil, and the element and the magnetizing coil are moved relative to each other, the magnetizing coil carrying an alternating current of substantially constant amplitude as well as a signal current. Preferably, there is a phase difference between the signal current and an intended magnetic field pattern.
    Type: Grant
    Filed: June 24, 1998
    Date of Patent: November 16, 1999
    Assignee: U.S. Philips Corporation
    Inventors: Jacobus J. M. Ruigrok, Marinus L. A. Vrinten, Andre A. Verhulst, Casper M. Smit
  • Patent number: 5973889
    Abstract: Single-channel magnetic head having a head face (1) which extends in a first direction (I) in which a magnetic record carrier (3) is relatively movable with respect to the magnetic head, and in a second direction (II) transverse to the first direction. The magnetic head has a structure of layers which, viewed in the first direction, are situated one on top of the other and extend substantially in the second direction and a third direction (III) transverse to the first and the second direction. The structure is provided with a magnetoresistive measuring element (5), a first magnetic element (7) and a second magnetic element (9). Both magnetic elements are electrically conducting, while the measuring element is arranged electrically in series between the two magnetic elements for passing a measuring current (i) through the measuring element substantially in the third direction. Each magnetic element has an electric contact face (7a, 9a).
    Type: Grant
    Filed: January 16, 1998
    Date of Patent: October 26, 1999
    Assignee: U.S. Philips Corporation
    Inventor: Jacobus J. M. Ruigrok
  • Patent number: 5933298
    Abstract: System comprising a magnetic head (1) and a measuring device connected to the magnetoresistive element. The magnetic head has a head face (5) with a transducing gap (15) and comprises a magnetoresistive element (13) and a magnetically conducting yoke with an electrically conducting element (11a) for generating a magnetic field intersecting the magnetoresistive element. The system also comprises a current device connected to the electrically conducting element.
    Type: Grant
    Filed: March 19, 1996
    Date of Patent: August 3, 1999
    Assignee: U.S. Philips Corporation
    Inventors: Lambertus Postma, Gerardus H.J. Somers, Jacobus J.M. Ruigrok
  • Patent number: 5914838
    Abstract: Magnetic head having a head face (1) and comprising a multilayer structure with a flux guide (7a, 7b), a magnetoresistive sensor (9) and an intermediate layer (13) present between the flux guide and said sensor. The intermediate layer comprises an anti-ferromagnetic oxide which insulates the sensor from the flux guide and also magnetically biases the sensor.
    Type: Grant
    Filed: January 31, 1997
    Date of Patent: June 22, 1999
    Assignee: U.S. Philips Corporation
    Inventors: Jacobus J. M. Ruigrok, Pieter J. van der Zaag
  • Patent number: 5726964
    Abstract: Scanning head including a magneto-optical element and scanning device including the scanning head. A scanning head having a head face (1) comprises flux-guiding elements (3a, 3b) and a magneto-optical element (5). The magneto-optical element is disposed in a gap plane (4) which extends between flux-guiding elements.
    Type: Grant
    Filed: July 13, 1995
    Date of Patent: March 10, 1998
    Assignee: U.S. Philips Corporation
    Inventors: Hans W. Van Kesteren, Jacobus J. M. Ruigrok
  • Patent number: 5600297
    Abstract: A device for detecting a magnetic field, which device comprises a magneto-resistive multilayer structure comprising a first magnetic layer (1) which is separated from a second magnetic layer by an interposed non-magnetic layer, the multilayer structure having a first in-plane reference axis (R.sub.1) coinciding with the direction in which magnetic flux is offered to the multilayer structure during operation, and a second in-plane reference axis (R.sub.2) which is perpendicular to the first reference axis (R.sub.1), whereby the magnetic easy axis (E.sub.1) of the first magnetic layer (1) is canted through an acute in-plane angle .alpha. with respect to the second reference axis (R.sub.2), and the magnetic easy axis (E.sub.2) of the second magnetic layer is canted in the opposite sense through an acute in-plane angle .beta. with respect to the second reference axis (R.sub.2).
    Type: Grant
    Filed: August 21, 1995
    Date of Patent: February 4, 1997
    Assignee: U.S. Philips Corporation
    Inventors: Jacobus J. M. Ruigrok, Martinus A. M. Gijs, Jacques C. S. Kools, Reinder Coehoorn, Wiepke Folkerts
  • Patent number: 5531016
    Abstract: Method of manufacturing a thin-film magnetic head in which a main layer (5) of a non-magnetic material is formed on a support, which layer is recessed by removing material from a side remote from the support, said recess being subsequently filled up with a soft-magnetic material for forming a flux guide (17a, 17b), whereafter the main layer provided with the filled recess is mechanochemically polished for forming a main surface (19) at which subsequently a layer of a magnetoresistive material is provided for forming a magnetoresistive element (23).
    Type: Grant
    Filed: March 22, 1994
    Date of Patent: July 2, 1996
    Assignee: U.S. Philips Corporation
    Inventors: Lambertus Postma, Henricus G. R. Maas, Jan Haisma, Jacobus J. M. Ruigrok, Gerardus H. J. Somers
  • Patent number: 5513057
    Abstract: Magnetic head unit comprising a magnetic head secured in a housing and having a magnetic head structure provided with a head face and at least one transducing gap terminating in the head face. A wear- resistant layer (31 ) having at least one alignment mark (35, 36, 37) occupying a defined position with respect to the transducing gap is provided on the head face.
    Type: Grant
    Filed: May 15, 1995
    Date of Patent: April 30, 1996
    Assignee: U.S. Philips Corporation
    Inventors: Victor Zieren, Jacobus J. M. Ruigrok, Mathijs De Jongh, Arnold Broese Van Groenou
  • Patent number: 5483735
    Abstract: Method of manufacturing a magnetoresistive magnetic head in which a first insulation layer (5) of a non-magnetic material is formed on a support face (3a), on which insulation layer a soft-magnetic layer having an upper face remote from the first insulation layer is formed by deposition of a soft-magnetic material. Subsequently a layer portion is removed for forming the flux-guiding elements (17a, 17b) and an aperture extending between said elements, and non-magnetic material for forming a second insulation layer (18) having an upper face remote from the soft-magnetic layer is deposited on the soft-magnetic layer and in the aperture formed therein, which second insulation layer has such a thickness that, viewed in a direction transverse to the support face, the smallest distance between the support face and the upper face of the second insulation layer is larger than the largest distance between the support face and the upper face of the soft-magnetic layer.
    Type: Grant
    Filed: March 22, 1994
    Date of Patent: January 16, 1996
    Assignee: U.S. Philips Corporation
    Inventors: Lambertus Postma, Jan Haisma, Jacobus J. M. Ruigrok, Gerardus H. J. Somers
  • Patent number: 5301418
    Abstract: A method of manufacturing one or more magnetic heads starts from a substrate (11) on which a first magnetic layer (13) is provided. A recess (15) is formed in this layer at the location of a transducing gap to be formed, after which a gap layer (19) is provided on a bounding wall (17) of the recess. Subsequently, the recess is filled with a second magnetic layer (23) and a counterblock (31) is provided on the layers after surface-polishing. Finally, a winding aperture is provided.
    Type: Grant
    Filed: April 1, 1992
    Date of Patent: April 12, 1994
    Assignee: U.S. Philips Corporation
    Inventors: Franciscus W. A. Dirne, Adrianus P. Severijns, Jacobus B. Giesbers, Jacobus J. M. Ruigrok
  • Patent number: 5270895
    Abstract: Combined read/write thin-film magnetic head comprising a read portion including a magneto-resistive element, a write portion including an inductive element, and a shared flux guide between the read and write portions. Improved separation of the read and write functions is achieved by providing the shared flux guide as a sandwich structure of two soft magnetic layers separated by an insulating layer, except that the soft-magnetic layers are interconnected in a magnetically conducting manner proximate to the head face.
    Type: Grant
    Filed: September 18, 1991
    Date of Patent: December 14, 1993
    Assignee: U.S. Philips Corporation
    Inventors: Jacobus J. M. Ruigrok, Franciscus A. Pronk
  • Patent number: 5258883
    Abstract: Thin-film magnetic head comprising a substrate (3), a magnetoresistive element (9) and two magnetically conducting flux guides (5, 7) extending substantially parallel to each other for magnetic cooperation with the magnetoresistive element (9). A non-magnetic read gap (13) adjacent to a head face (1) extends between the flux guides. The first flux guide (5) is built up in layers and comprises a first soft-magnetic layer (5A) opposite the second flux guide (7), a second soft-magnetic layer (5B) and an insulation layer (5C) of a non-magnetic material extending substantially parallel to the substrate and situated between these soft-magnetic layers. Said soft-magnetic layers join in a common end portion (5E) proximate to the head face. The first soft-magnetic layer is an interrupted layer having two spatially separated layer portions (5AA, 5AB), bridged by the magnetoresistive element.
    Type: Grant
    Filed: September 17, 1991
    Date of Patent: November 2, 1993
    Assignee: U.S. Philips Corporation
    Inventor: Jacobus J. M. Ruigrok