Patents by Inventor Petrus C. J. Hoeven

Petrus C. J. Hoeven 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: 5587980
    Abstract: Method of deriving a quality signal for a binary read signal having bit cells of constant length, and reading and recording devices which employ that method. During a reading process, an information pattern of optically detectable effects, representing certain of the bit cells, is scanned. A read signal is generated therefrom in which first read signal portions that exceed a reference value correspond to the effects. The quality signal is derived (in an analysis circuit) from the first read signal portions based on a measure of the deviation of first read signal portions corresponding to a particular length or mutual differences between length deviation of first read signal portions of different lengths. The quality signal can be used for adapting a recording strategy used in the recording of information, or for setting an equalizing filter.
    Type: Grant
    Filed: March 29, 1994
    Date of Patent: December 24, 1996
    Assignee: U.S. Philips Corporation
    Inventors: Johannes G. F. Kablau, Winslow M. Mimnagh, Petrus C. J. Hoeven
  • Patent number: 5233577
    Abstract: A magneto-optical recording apparatus provided with a magnetic field modulator (8). The magnetic-field modulator (8) has a field coil (18) for generating a magnetic field and switches (11,12,15,16,22) for coupling at least one terminal (17) of the magnet coil (18) to a first potential point (10) at a first potential (Vp) or a second potential point (14) at a second potential (Vn) depending on the logic value of a control signal (vs), in order to produce in the field coil an alternating current whose polarity depends on the logic value. The field coil (18) is arranged in a parallel resonant circuit (18,21). The switches have means (12,16) for inhibiting, after the terminal (17) has been uncoupled from one of the potential points (10,14), current supply from the other potential point for a time interval corresponding to half the resonant period of the resonant circuit (18,21). This magnetic-field modulator provides a very rapid reversal of the current through the field coil.
    Type: Grant
    Filed: February 3, 1992
    Date of Patent: August 3, 1993
    Assignee: U.S. Philips Corp.
    Inventors: Johannes L. Bakx, Petrus C. J. Hoeven
  • Patent number: 4901300
    Abstract: A method of and apparatus (FIG. 4) for recording an information signal (Vi), in particular an EFM-modulated signal, are revealed, which information signal comprises time-code signals which alternate with first time-synchronization signals. The record carrier (1) which is employed is provided with a preformed servo track (4) which exhibits a periodic track modulation whose frequency is modulated in conformity with the position-information signal (FIG. 2). The position-information signal (FIG. 2) comprises position-code signals (12) which alternate with position-synchronization signals (11). During recording a fixed phase relationship between the time-synchronization signals and the position-synchronization signals (11) is maintained, so that the portion (141) of the servo track (4) in which the time-synchronization signals are recorded are situated at fixed positions relative to the servo-track portions (140) which represent the position-synchronization signals (11).
    Type: Grant
    Filed: November 1, 1988
    Date of Patent: February 13, 1990
    Assignee: U.S. Philips Corporation
    Inventors: Paulus C. M. Van Der Zande, Petrus C. J. Hoeven