Patents by Inventor Steven P. Graves

Steven P. Graves 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).

  • Driver circuit for an electroluminescent matrix-addressed display
    Patent number: 4554539
    Abstract: A driver circuit which operates in a switching mode is provided for an electroluminescent matrix-addressed display. The circuit has a row driver which switches a timed ramp voltage to a selected row of the display. A column driver is used to switch selected columns from a low to a high voltage. The column driver is pulse-modulated (PPM or PWM) so that each pulse is timed to coincide with the ramped voltage to provide a differential voltage peak which provides the desired brightness (or grey scale) at the pixel where the driven row and column cross.
    Type: Grant
    Filed: November 8, 1982
    Date of Patent: November 19, 1985
    Assignee: Rockwell International Corporation
    Inventor: Steven P. Graves