Patents by Inventor Richard Alexander Erhart

Richard Alexander Erhart 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: 6295621
    Abstract: A display driver circuit for driving a flat panel display including circuitry for detecting integrity of bonding of outputs of the driver circuit to the display. The bond integrity detecting circuitry includes a test mode current source which applies current to the output being tested to raise its voltage to a threshold level. At a defined sampling time following initiation of application of the test mode current, the voltage on the output being tested is compared to the threshold level, and the result of the comparison is stored and output from the driver circuit. If the voltage of the output has not reached the threshold level at the defined sampling time, the output connection is determined to be good.
    Type: Grant
    Filed: April 22, 1993
    Date of Patent: September 25, 2001
    Assignee: Medtronic, Inc
    Inventors: Richard Alexander Erhart, Richard Brian Nelson
  • Patent number: 6201522
    Abstract: A power-saving column driver integrated circuit, and a power-saving method for driving a liquid crystal display, include a series of multiplexers coupled to the columns of the display. The multiplexers selectively couple each of the columns to a common external storage capacitor during a portion of each row drive period for discharging each of the pixels in the selected row of the liquid crystal display to a median bias voltage. During the remaining portion of each row drive period, the multiplexers selectively couple voltage drivers to the columns of the LCD pixel array for applying a desired driving voltage to each column of the array. The polarity of the driving voltages applied to each column alternates on succeeding row drive periods, and the resulting voltage that is summed on the storage capacitor averages to the median bias voltage.
    Type: Grant
    Filed: December 21, 1998
    Date of Patent: March 13, 2001
    Assignee: National Semiconductor Corporation
    Inventors: Richard Alexander Erhart, Gerald T. Harder
  • Patent number: 6040815
    Abstract: A column-driver integrated circuit, and related method, for driving the columns of LCD displays uses paired digital-to-analog converters to provide analog signals in an upper voltage range and in a lower voltage range. During a first drive cycle, first and second digital data words are provided to the first and second digital-to-analog converters; the first and second digital data words represent the magnitudes, within the upper voltage range and lower voltage range, respectively, of the analog signals to be driven onto first and second columns of the LCD display. The analog signal generated by the first D/A converter is selected, as by a multiplexer, onto the first column of the display, and the analog signal generated by the second D/A converter is selected onto the second column of the display.
    Type: Grant
    Filed: February 20, 1998
    Date of Patent: March 21, 2000
    Assignee: Vivid Semiconductor, Inc.
    Inventors: Richard Alexander Erhart, James Richard Kozicek
  • Patent number: 5852426
    Abstract: A power-saving column driver integrated circuit, and a power-saving method for driving a liquid crystal display, include a series of multiplexers coupled to the columns of the display. The multiplexers selectively couple each of the columns to a common external storage capacitor during a portion of each row drive period for discharging each of the pixels in the selected row of the liquid crystal display to a median bias voltage. During the remaining portion of each row drive period, the multiplexers selectively couple voltage drivers to the columns of the LCD pixel array for applying a desired driving voltage to each column of the array. The polarity of the driving voltages applied to each column alternates on succeeding row drive periods, and the resulting voltage that is summed on the storage capacitor averages to the median bias voltage.
    Type: Grant
    Filed: March 21, 1996
    Date of Patent: December 22, 1998
    Assignee: Vivid Semiconductor, Inc.
    Inventors: Richard Alexander Erhart, Gerald T. Harder
  • Patent number: 5818252
    Abstract: An integrated circuit assembly using tape automated bonding (TAB) reduces the number of TAB test pads formed upon the TAB film, for purposes of testing the integrated circuit prior to surface mounting, by sharing at least some of such test pads between at least two output terminals of the integrated circuit. A control signal indicates to the integrated circuit that a TAB test mode of operation is in effect. A second control signal indicates which of the two output signals should be enabled to the shared test pad during the TAB test mode. Multiplexers are provided at the output terminals, and are responsive to such control signals, for selectively allowing one of such output signals to be conducted to the test pad, while temporarily presenting a high impedance at the other output terminal. A method of testing such integrated circuit assembly includes the step of trimming such test pads from the tape automated bonding film after testing and before surface mounting.
    Type: Grant
    Filed: September 19, 1996
    Date of Patent: October 6, 1998
    Assignee: Vivid Semiconductor, Inc.
    Inventors: Edward Carl Fullman, Richard Brian Nelson, James Richard Kozicek, Richard Alexander Erhart
  • Patent number: 5754156
    Abstract: A column-driver integrated circuit, and related method, for driving the columns of LCD displays uses paired digital-to-analog converters to provide analog signals in an upper voltage range and in a lower voltage range. During a first drive cycle, first and second digital data words are provided to the first and second digital-to-analog converters; the first and second digital data words represent the magnitudes, within the upper voltage range and lower voltage range, respectively, of the analog signals to be driven onto first and second columns of the LCD display. The analog signal generated by the first D/A converter is selected, as by a multiplexer, onto the first column of the display, and the analog signal generated by the second D/A converter is selected onto the second column of the display.
    Type: Grant
    Filed: September 19, 1996
    Date of Patent: May 19, 1998
    Assignee: Vivid Semiconductor, Inc.
    Inventors: Richard Alexander Erhart, James Richard Kozicek