Patents by Inventor Jan J. Janse

Jan J. Janse 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).

  • Magneto-optical recorder with servo control system for a magnetic-field modulation system
    Patent number: 5163032
    Abstract: The invention relates to a magneto-optical recorder with magnetic-field modulation. It comprises a laser (8) for producing a light beam (6), an optical focussing system (9) for forming a focal spot (12), and a servo device (10) for maintaining the focal spot (12) in focus on the surface of a thermo-magnetic record carrier (4), and for supplying a correction signal (V.sub.c) which is representative of the position of the surface of said carrier. A current modulator modulates the current through a coil (15) of a magnetic head. A compensation device (7) is responsive to said correction signal (V.sub.c) to change a parameter influencing the field of the coil, in such a way that the field strength at the surface of said carrier (4) is substantially independant of the position of said surface.
    Type: Grant
    Filed: June 12, 1991
    Date of Patent: November 10, 1992
    Assignee: U.S. Philips Corp.
    Inventors: Jacob M. Van Nieuwland, Heemskerk: Jacobus P. J., Johannes L. Bakx, Jan J. Janse