Patents by Inventor Hendrik Eisema

Hendrik Eisema 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: 3989893
    Abstract: An apparatus for reading a record carrier on which a combined video signal is recorded in a single track, in particular a disc-shaped record carrier on which the signal is recorded in optically coded form. In order to reduce the disturbing effect of dropouts on the eventually obtained sound signal, a portion of the the video signal is subjected to the action of a clamping circuit. Said clamping circuit normally transfers the applied modulated video signal unmodified. During a dropout the modulated video signal consisting of the modulated sound and pilot signal is clamped at its average value by means of said clamping circuit, so that a substantial improvement is obtained in respect of the sound signal. Thus, the length of time of sound signal clamping is minimized and the sound quality is improved.
    Type: Grant
    Filed: December 4, 1974
    Date of Patent: November 2, 1976
    Assignee: U.S. Philips Corporation
    Inventor: Hendrik Eisema