Patents by Inventor David C. Stevenson

David C. Stevenson 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: 7726758
    Abstract: A method and device for providing a plurality of fire pulses in an ink jet printer, which includes a production of a plurality of fire signals. Each fire signal of the plurality of fire signals are asserted at a different timing than the other of the plurality of fire signals. The plurality of fire signals are combined to form a composite fire signal that maintains the different timing.
    Type: Grant
    Filed: December 18, 2007
    Date of Patent: June 1, 2010
    Assignee: Lexmark International, Inc.
    Inventors: Lucas D. Barkley, David C. Stevenson
  • Patent number: 7469107
    Abstract: A method for providing a virtual replenishing of a supply item with an imaging substance includes the steps communicating to a database a first serial number associated with a first supply item; comparing the first serial number with a plurality of serial numbers stored in the database; receiving from the database one of a first data indicating non-correspondence between the first serial number with one of the plurality of serial numbers and a second data indicating correspondence between the first serial number with one of the plurality of serial numbers, wherein the second data includes a verification key; and if the verification key corresponds to the first key stored in the memory associated with the first supply item, then performing the step of allocating at least a portion of a surplus amount of the imaging substance contained in the first supply item for use.
    Type: Grant
    Filed: July 23, 2003
    Date of Patent: December 23, 2008
    Assignee: Lexmark International, Inc.
    Inventors: Christopher A Adkins, Douglas L. Robertson, David C. Stevenson, Barry B. Stout
  • Patent number: 7350888
    Abstract: A method and device for providing a plurality of fire pulses in an ink jet printer, which includes a production of a plurality of fire signals. Each fire signal of the plurality of fire signals are asserted at a different timing than the other of the plurality of fire signals. The plurality of fire signals are combined to form a composite fire signal that maintains the different timing.
    Type: Grant
    Filed: December 15, 2003
    Date of Patent: April 1, 2008
    Assignee: Lexmark International, Inc.
    Inventors: Lucas D. Barkley, David C. Stevenson
  • Patent number: 6974200
    Abstract: A programmable memory on an inkjet printhead chip. The memory includes at least a memory array that has a plurality of memory elements, and a bipolar device that isolates a memory element from another memory element in the memory array.
    Type: Grant
    Filed: November 14, 2003
    Date of Patent: December 13, 2005
    Assignee: Lexmark International, Inc.
    Inventors: John G. Edelen, George K. Parish, Krisit M. Rowe, David C. Stevenson
  • Patent number: 4893257
    Abstract: A character generator with multidirectional scan and variable line and character (or symbol) size capability is disclosed. Universality is implemented by producing a serial binary stream which can be used to print or display in any of eight combinations of scan direction and progression, that is, for scan direction left to right, or vice versa, progressing up or down, or scan direction top or bottom or vice versa, progressing left or right. In formatting the serial binary stream, a font is accessed (for basic symbol definition), which selectively provides for orthogonal scan of the symbol definitions. Variable line size is implemented by terminating a symbol row (or line) based on a predetermined size criteria regardless of the comparable font dimension and "filling" up to the line size to the extent the corresponding font dimension is less than the predetermined size criteria.
    Type: Grant
    Filed: November 10, 1986
    Date of Patent: January 9, 1990
    Assignee: International Business Machines Corporation
    Inventors: Ruben Dominguez, Jr., David E. Finlay, Stephen D. Hanna, Jesus C. Lopez, David C. Stevenson, Donald W. Zegafuse, Jr., deceased
  • Patent number: 4841453
    Abstract: A character generator with multidirectional scan and variable line and character (or symbol) size capability. Universality is implemented by producing a serial binary stram which can be used to print or display in any of eight combinations of scan direction and progression, that is, for scan direction left to right, or vice versa, progressing up or down, or scan direction top to bottom or vice versa, progressing left or right. In formatting the serial binary stream, a font is accessed (for basic symbol definition), which selectively provides for orthogonal scans of the symbol definitions. Variable line size is implemented by terminating a symbol row (or line) based on a predetermined size criteria regardless of the comparable font dimension and "filling" up to the line size to the extent the corresponding font dimension is less than the predetermined size criteria.
    Type: Grant
    Filed: November 10, 1986
    Date of Patent: June 20, 1989
    Assignee: IBM Corporation
    Inventors: David E. Finlay, Stephen D. Hanna, David C. Stevenson, John T. Varga