Patents by Inventor Mike R. Coleman

Mike R. Coleman 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).

  • Circuit for driving a multiple-element display
    Patent number: 4841200
    Abstract: A circuit for driving a display device having n display elements, where n is a positive integer greater than one, comprises a device for poviding a repetitive digital signal having a predetermined sequence of n digital values. The digital signal is converted to analog form in accordance with a predetermined transfer function and the resulting analog signal is compared with a second signal. A display enable signal is generated in the event that the magnitude of the analog signal bears a predetermined relationship to the magnitude of the second signal. A decoder circuit has a plurality of output terminals at which n distinct output signals, corresponding respectively to the n digital values, can be provided. The decoder circuit is responsive to the display enable signal for providing one of the n output signals when it receives the corresponding one of the n digital values.
    Type: Grant
    Filed: October 5, 1987
    Date of Patent: June 20, 1989
    Assignee: Tektronix, Inc.
    Inventors: Edward J. Cleary, Jr., Mike R. Coleman, Michael R. Jones
  • Digital signal synthesis using low frequency sampling clock
    Patent number: 4823090
    Abstract: A digital signal synthesizer stores a representation of a desired analog signal in the form of digital samples. The digital samples are converted to an analog signal by a sample clock having a frequency greater than or equal to twice the bandwidth of the desired analog signal. The analog signal is band pass filtered to recover the desired analog signal.
    Type: Grant
    Filed: October 2, 1987
    Date of Patent: April 18, 1989
    Assignee: Tektronix, Inc.
    Inventors: Mike R. Coleman, John J. Ciardi
  • Digital peak-hold circuit
    Patent number: 4686390
    Abstract: A digital peak-hold detector for determining the peak value of an input analog voltage to be displayed on a multiple-element display device detects when the value of the input analog voltage exceeds the value of a ramp-like waveform generated from a counter which repetitively counts down from a number equal to the total number of display elements to zero to generate a compare signal. A control circuit strobes the count corresponding to the peak value into a storage register when the value of the input analog voltage exceeds the current peak value in the storage register. A digital comparator compares the current peak value from the storage register with the repetitive count from the counter and outputs an update signal when the value of the count is greater than the current peak value. The update signal is combined with the compare signal by the control circuit to make the determination whether to update the current peak value.
    Type: Grant
    Filed: June 26, 1986
    Date of Patent: August 11, 1987
    Assignee: Tektronix, Inc.
    Inventors: Edward J. Cleary, Jr., Mike R. Coleman