Patents Represented by Attorney John D. Johnson, Jr., Alexander C. Winkelman
  • Patent number: 4857906
    Abstract: A matrix display drive circuit is disclosed which generates multilevel and multiphase, time-variant drive waveforms for driving the rows and columns of a ferrolectric liquid crystal matrix display. The circuit can provide up (write) and down (erase) pulses selectively to each pixel of the display using standard twisted-nematic type liquid crystal display drivers. A complex waveform generator provides multilevel, multiphase control signals to the supply voltage inputs of the drivers. Timing and synchronizing signals are extracted from the graphics data and timing source outputs to allow such multilevel, multiphase signals as may be required for the effective multiplexing of the display matrix.
    Type: Grant
    Filed: October 8, 1987
    Date of Patent: August 15, 1989
    Assignee: Tektronix, Inc.
    Inventor: Arlie R. Conner