Patents by Inventor Piet F. Bongers

Piet F. Bongers 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).

  • Method of recording information on a record carrier of the thermomagnetic type, and device for carrying out the method
    Patent number: 5126985
    Abstract: When information is recorded on a record carrier (1) of the thermomagnetic type, the thermomagnetic recording layer (4) is scanned by a magnetic field generated by a magnetic-field modulator (7). The magnetic field is modulated depending on an information signal (Vi). Moreover, the scanned portion of the record carrier (1) is at the same time locally heated by radiation pulses (10) generated by an optical scanning device (5). By means of radiation pulses (10) the record carrier is heated above a write temperature (Ts), above which temperature the magnetization of the record carrier assumes the direction dictated by the magnetic field. A synchronizing circuit (9) generates the control signal (Vm) for modulating the magnetic field and the control signal (Vr) for generating the radiation pulses, in such a way that at the end of the radiation pulses the field strength is sufficiently high for the heated area of the record carrier to be magnetized in the directio dictated by the magnetic field.
    Type: Grant
    Filed: May 14, 1991
    Date of Patent: June 30, 1992
    Assignee: U.S. Philips Corp.
    Inventors: Johannes H. M. Spruit, Hendricus F. J. J. Van Tongeren, Piet F. Bongers, Bernardus A. J. Jacobs
  • Magnetic head
    Patent number: 4568993
    Abstract: Magnetic head for a magnetic recording and playback apparatus includes a core of a Mn--Zn-ferrous ferrite having a very high saturation magnetization. The Mn--Zn-ferrous ferrite has a composition (not counting optional substitutions) according to the formulaMn.sub.a Zn.sub.b Fe.sub.c.sup.II Fe.sub.e.sup.III O.sub.4with0<a.ltoreq.0.550.06.ltoreq.b.ltoreq.0.40.25.ltoreq.c.ltoreq.0.9(a+b+c=1).The result is that the magnetic head may be used in combination with magnetic tapes having a very high coercive force (up to 104 kA/m (1300 Oersted) and may be used for transducing signals having a frequency of a few MHz.
    Type: Grant
    Filed: January 24, 1983
    Date of Patent: February 4, 1986
    Assignee: U.S. Philips Corporation
    Inventors: Doeko Stoppels, Piet F. Bongers, Johannes P. M. Damen, Eelco G. Visser
  • Luminescent screen
    Patent number: 4298820
    Abstract: A luminescent screen consisting of one self-supporting monocrystalline body and having a luminescent surface layer with V-shaped grooves. Such screens may be exposed to radiation having a larger energy than was usual so far with phosphor screens and have a very large luminous efficiency. In addition the resolving power is very large since there are no particles with limiting dimensions. Such screens may be used for displaying very bright pictures suitable for projection on a projection screen.
    Type: Grant
    Filed: June 18, 1979
    Date of Patent: November 3, 1981
    Assignee: U.S. Philips Corporation
    Inventors: Piet F. Bongers, Maurits W. van Tol, John M. Robertson
  • Magnetic bubble multilayer arrangement
    Patent number: 4151602
    Abstract: A magnetic bubble device comprising a non-magnetic substrate layer, and a sequence of magnetic layers joined to each other and to the magnetic substrate layer, e.g. by epitaxial growing of crystalline layers, whereby at least two of the magnetic layers may accommodate magnetic bubbles which are stably joined through an interlayer magnetic compensation wall, or by an essentially finite potential barrier.
    Type: Grant
    Filed: February 17, 1978
    Date of Patent: April 24, 1979
    Assignee: U.S. Philips Corporation
    Inventors: Jan Haisma, Klaas L. L. Van Mierloo, Ulrich E. Enz, Piet F. Bongers