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).
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Patent number: 6747854Abstract: 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: GrantFiled: January 12, 1998Date of Patent: June 8, 2004Assignee: Koninklijke Philips Electronics N.V.Inventors: Jacobus J. M. Ruigrok, Gerardus H. J. Somers
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Patent number: 6486662Abstract: 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: GrantFiled: October 26, 1998Date of Patent: November 26, 2002Assignee: Koninklijke Philips Electronics N.V.Inventors: Jacobus J. M. Ruigrok, Reinder Coehoorn, Pieter J. Van Der Zaag
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Patent number: 6278588Abstract: 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: GrantFiled: November 1, 1999Date of Patent: August 21, 2001Assignee: U.S. Philips CorporationInventor: Jacobus J. M. Ruigrok
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Patent number: 6266217Abstract: 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: GrantFiled: March 1, 1999Date of Patent: July 24, 2001Assignee: U.S. Philips CorporationInventors: Jacobus J. M. Ruigrok, Pieter J. Van Der Zaag
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Patent number: 6238731Abstract: 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: GrantFiled: September 7, 1999Date of Patent: May 29, 2001Assignee: U.S. Philips CorporationInventors: Jacobus J. M. Ruigrok, Pieter J. Van Der Zaag, Wiepke Folkerts, Lambertus Postma, Ronald M. Wolf, Johannes F. M. Cillessen
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Patent number: 6233126Abstract: 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: GrantFiled: August 15, 1996Date of Patent: May 15, 2001Assignee: U.S. Philips CorporationInventors: Pieter J. Van der Zaag, Jacobus J. M. Ruigrok, Harald Van Kampen
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Patent number: 6205007Abstract: 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: GrantFiled: November 22, 1993Date of Patent: March 20, 2001Assignee: U.S. Philips CorporationInventors: Jacobus J. M. Ruigrok, Pieter J. Van Der Zaag, Wiepke Folkerts, Lambertus Postma, Ronald M. Wolf, Johannes F. M. Cillessen
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Patent number: 6110539Abstract: 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: GrantFiled: January 27, 1999Date of Patent: August 29, 2000Assignee: U.S. Philips CorporationInventors: Pascal J.H. Bloemen, Jacobus J.M. Ruigrok
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Patent number: 5984745Abstract: 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: GrantFiled: June 24, 1998Date of Patent: November 16, 1999Assignee: U.S. Philips CorporationInventors: Jacobus J. M. Ruigrok, Marinus L. A. Vrinten, Andre A. Verhulst, Casper M. Smit
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Patent number: 5973889Abstract: 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: GrantFiled: January 16, 1998Date of Patent: October 26, 1999Assignee: U.S. Philips CorporationInventor: Jacobus J. M. Ruigrok
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Patent number: 5933298Abstract: 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: GrantFiled: March 19, 1996Date of Patent: August 3, 1999Assignee: U.S. Philips CorporationInventors: Lambertus Postma, Gerardus H.J. Somers, Jacobus J.M. Ruigrok
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Patent number: 5914838Abstract: 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: GrantFiled: January 31, 1997Date of Patent: June 22, 1999Assignee: U.S. Philips CorporationInventors: Jacobus J. M. Ruigrok, Pieter J. van der Zaag
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Patent number: 5726964Abstract: 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: GrantFiled: July 13, 1995Date of Patent: March 10, 1998Assignee: U.S. Philips CorporationInventors: Hans W. Van Kesteren, Jacobus J. M. Ruigrok
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Patent number: 5600297Abstract: 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: GrantFiled: August 21, 1995Date of Patent: February 4, 1997Assignee: U.S. Philips CorporationInventors: Jacobus J. M. Ruigrok, Martinus A. M. Gijs, Jacques C. S. Kools, Reinder Coehoorn, Wiepke Folkerts
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Patent number: 5531016Abstract: 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: GrantFiled: March 22, 1994Date of Patent: July 2, 1996Assignee: U.S. Philips CorporationInventors: Lambertus Postma, Henricus G. R. Maas, Jan Haisma, Jacobus J. M. Ruigrok, Gerardus H. J. Somers
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Patent number: 5513057Abstract: 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: GrantFiled: May 15, 1995Date of Patent: April 30, 1996Assignee: U.S. Philips CorporationInventors: Victor Zieren, Jacobus J. M. Ruigrok, Mathijs De Jongh, Arnold Broese Van Groenou
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Patent number: 5483735Abstract: 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: GrantFiled: March 22, 1994Date of Patent: January 16, 1996Assignee: U.S. Philips CorporationInventors: Lambertus Postma, Jan Haisma, Jacobus J. M. Ruigrok, Gerardus H. J. Somers
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Patent number: 5301418Abstract: 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: GrantFiled: April 1, 1992Date of Patent: April 12, 1994Assignee: U.S. Philips CorporationInventors: Franciscus W. A. Dirne, Adrianus P. Severijns, Jacobus B. Giesbers, Jacobus J. M. Ruigrok
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Patent number: 5270895Abstract: 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: GrantFiled: September 18, 1991Date of Patent: December 14, 1993Assignee: U.S. Philips CorporationInventors: Jacobus J. M. Ruigrok, Franciscus A. Pronk
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Patent number: 5258883Abstract: 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: GrantFiled: September 17, 1991Date of Patent: November 2, 1993Assignee: U.S. Philips CorporationInventor: Jacobus J. M. Ruigrok