Patents by Inventor Derk J. Adelerhof

Derk J. Adelerhof 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: 6580583
    Abstract: A thin-film magnetic head has a semiconductor substrate in which there is an integrated circuit, and on which a magnetic layer structure is arranged. During manufacturing the integrated circuit is formed on one side of the semiconductor substrate, and that side of the semiconductor substrate is then secured to a carrier body by a securing layer. The substrate may then be ground or etched to a thickness less than 35&mgr;m before forming the magnetic layer structure on the opposite side. Securing to the carrier body prevents deformation of the layer structure during manufacturing, so that the resulting head has reproducible properties. Preferably a support body is secured over the layer structure. The head face is then formed such that the layer structure and the support and carrier bodies terminate in it.
    Type: Grant
    Filed: November 7, 1997
    Date of Patent: June 17, 2003
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Derk J. Adelerhof, Ronald Dekker, Henricus G. R. Maas
  • Patent number: 6577121
    Abstract: Magnetoresistive sensor (1) for measuring relative displacements of construction parts (2, 3). A magnetoresistive element (4) is formed on a surface (7) of a substrate (8). A magnet system (5) generates a magnetic field (13) having a component (14) directed parallel to the substrate surface at the area of the magnetoresistive element. Upon the relative displacement of the construction parts, this field component extends at different angles &agr; to the magnetoresistive element and is so large that the magnetoresistive element is always magnetically saturated during the displacement. Upon a relative displacement of the construction parts, the magnetoresistive element describes a path (20, 21) with respect to the magnet system. The sensor is suitable for measuring rotations through angles up to 360° and for measuring large translations.
    Type: Grant
    Filed: July 11, 2000
    Date of Patent: June 10, 2003
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Derk J. Adelerhof, Kars-Michiel H. Lenssen
  • Patent number: 6559638
    Abstract: A magnetic position detector includes a soft magnetic target wheel, a magnetic sensor and a permanent magnet. The invention includes magnetoresistive sensors in several geometrical configurations of the target wheel, the sensor and the magnet. All configurations result in a big change of direction of the magnetic field at the location of the sensor as a result of a rotation of the target wheel. The configurations have in common that the direction of the magnetic field at the location of the sensor, as generated by the permanent magnet, is predominantly in the plane of the sensor surface, both when the sensor is next to a slot and next to a tooth of the target wheel, the surface of the sensor being substantially normal to the direction of movement of the target wheel.
    Type: Grant
    Filed: February 8, 2000
    Date of Patent: May 6, 2003
    Assignee: Koninklijke Philips Electronics N.V.
    Inventor: Derk J. Adelerhof
  • Patent number: 6317302
    Abstract: A thin-film magnetic read head device comprises an end face extending in a first direction, in which a magnetic information carrier is movable with respect to the magnetic head device, and in a second direction, perpendicular to said first direction. The magnetic head device further comprises a multilayer structure with at least two soft-magnetic layers separated by a magnetic insulation layer and with at least one exchange biasing layer, which multilayer structure extends in the second direction and in a third direction, perpendicular to the first and the second direction, and forms at least one flux path in the first and the third direction. The exchange coupling between one of the soft-magnetic layers and the exchange biasing layer is at least partly reduced locally, i.e. interrupted or at least substantially reduced, in at least the second direction, while the exchange biasing layer extends uninterruptedly in the region of said reductions.
    Type: Grant
    Filed: August 2, 1999
    Date of Patent: November 13, 2001
    Assignee: U.S. Philips Corporation
    Inventors: Hans W. Van Kesteren, Derk J. Adelerhof, Reinder Coehoorn
  • Patent number: 6271998
    Abstract: A thin film shielded magnetic read head device comprises an end face extending in a first direction, in which a magnetic information carrier is movable with respect to the magnetic head device, and in a second direction, perpendicular to said first direction. The magnetic head device further comprises shield forming flux guiding elements for magnetic cooperation with the information carrier, which elements extend in the second direction and in a third direction, perpendicular to the first and the second direction. A number of magnetoresistive elements each having a spin tunnel junction structure is provided, which number of magnetoresistive elements corresponds to with the number of magnetic channels of the magnetic head device. One of said shields forms a common contact lead for the current through said magnetoresistive elements. Thin film magnetic read head device is applied in a system for reading information from a magnetic information carrier.
    Type: Grant
    Filed: August 24, 1999
    Date of Patent: August 7, 2001
    Assignee: U.S. Philips Corporation
    Inventors: Reinder Coehoorn, Jacques C. S. Kools, Derk J. Adelerhof