Patents by Inventor John H. Riseman, deceased

John H. Riseman, deceased 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: 4800442
    Abstract: An apparatus for generating a high quality image from a digital video signal includes a system for gamma correcting the digital video signal with a digital look up table and for converting the resultant digital signal to an analog video signal. Another circuit generates a triangular wave reference pattern signal and a comparator compares the analog video signal with the triangular wave reference pattern signal to form a pulse-width-modulated signal. A raster scanning print engine producing, for example, a laser beam, scans over a recording medium in accordance with the pulse-width-modulated signal, thereby forming an image of high quality on the recording medium of a print engine. This apparatus can also be used with an analog video signal by first converting the analog video signal to a digital video signal with an analog to digital converter.
    Type: Grant
    Filed: May 18, 1987
    Date of Patent: January 24, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: John H. Riseman, deceased, John J. Smith, Alice M. d'Entremont, Craig E. Goldman