Patents by Inventor Stefan Mark

Stefan Mark 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: 9046544
    Abstract: A system for determining motor speed of a brush DC motor, including a first filter for receiving a substantially low frequency portion of a sensed current of the motor and parameters corresponding thereto, for calculating a speed estimate of the motor; an adaptive bandpass filter having a center frequency corresponding to the speed estimate of the first filter, for receiving the sensed current and substantially isolating a first periodic current fluctuation thereof. A detected frequency of the first periodic current fluctuation corresponds to the speed of the brush DC motor. The system may include a tracking frequency selection block for selecting a frequency component of the sensed current and providing same to the first filter, wherein the speed estimate is based in part upon the selected frequency component.
    Type: Grant
    Filed: June 11, 2012
    Date of Patent: June 2, 2015
    Assignee: Lexmark International, Inc.
    Inventor: Stefan Mark Atay
  • Patent number: 9000710
    Abstract: A system for determining motor speed of a brush DC motor in an apparatus, including a first filter for receiving a substantially DC component of the motor current and parameters corresponding to the brush DC motor, for calculating a speed estimate thereof; an adaptive bandpass filter having a center frequency corresponding to the speed estimate of the first filter, for receiving the motor current and substantially isolating a periodic current fluctuation thereof; a block for determining a frequency of the periodic current fluctuation, the current fluctuation corresponding to motor speed of the brush DC motor. The adaptive bandpass filter uses debounce filtering to reduce rapid filter passband switching, and a run-in period prior to passband switching to obviate transient effects of filter switching.
    Type: Grant
    Filed: June 11, 2012
    Date of Patent: April 7, 2015
    Assignee: Lexmark International, Inc.
    Inventor: Stefan Mark Atay
  • Publication number: 20120326705
    Abstract: A system for determining motor speed of a brush DC motor in an apparatus, including a first filter for receiving a substantially DC component of the motor current and parameters corresponding to the brush DC motor, for calculating a speed estimate thereof; an adaptive bandpass filter having a center frequency corresponding to the speed estimate of the first filter, for receiving the motor current and substantially isolating a periodic current fluctuation thereof; a block for determining a frequency of the periodic current fluctuation, the current fluctuation corresponding to motor speed of the brush DC motor. The adaptive bandpass filter uses debounce filtering to reduce rapid filter passband switching, and a run-in period prior to passband switching to obviate transient effects of filter switching.
    Type: Application
    Filed: June 11, 2012
    Publication date: December 27, 2012
    Inventor: Stefan Mark Atay
  • Publication number: 20120330595
    Abstract: A system for determining motor speed of a brush DC motor in an apparatus, including circuitry for sensing current in the brush DC motor; a first filter for receiving a substantially DC component of the sensed current and parameters corresponding to the brush DC motor, for calculating a speed estimate thereof; an adaptive bandpass filter having a center frequency corresponding to the speed estimate of the first filter, for receiving the sensed current and substantially isolating a periodic current fluctuation thereof; a block for determining a frequency of the periodic current fluctuation, the periodic current fluctuation frequency being a commutation frequency of the brush DC motor and corresponding to motor speed of the brush DC motor. The motor speed determined from the periodic current fluctuation of the motor current is then used to control the speed of the motor.
    Type: Application
    Filed: June 11, 2012
    Publication date: December 27, 2012
    Inventor: Stefan Mark Atay
  • Publication number: 20120326704
    Abstract: A system for determining motor speed of a brush DC motor, including a first filter for receiving a substantially low frequency portion of a sensed current of the motor and parameters corresponding thereto, for calculating a speed estimate of the motor; an adaptive bandpass filter having a center frequency corresponding to the speed estimate of the first filter, for receiving the sensed current and substantially isolating a first periodic current fluctuation thereof. A detected frequency of the first periodic current fluctuation corresponds to the speed of the brush DC motor. The system may include a tracking frequency selection block for selecting a frequency component of the sensed current and providing same to the first filter, wherein the speed estimate is based in part upon the selected frequency component.
    Type: Application
    Filed: June 11, 2012
    Publication date: December 27, 2012
    Inventor: Stefan Mark Atay
  • Publication number: 20120010377
    Abstract: The invention refers to a catalyst system for the polymerization of olefins including a diorganohydroborane molecular weight modifier. By addition of diorganohydroborane to the catalyst system it is possible to control the molecular weight of a polyolefin to higher values.
    Type: Application
    Filed: March 24, 2010
    Publication date: January 12, 2012
    Applicant: BASELL POLYOLEFINE GMBH
    Inventors: Marc Oliver Kristen, Markus Enders, Stefan Mark
  • Publication number: 20030023664
    Abstract: Caching is a widely used technology on the Web, particularly by search engines which follow hyperlinks and generate indexes and directories of Web pages and their contents. Indeed, some search engines allow users to view pages as they were last retrieved by the search engine. Whether a given page exits in the cache or not, however, is completely arbitrary, and so is the time of its retrieval. The ‘Web page cache-on-demand’ process allows Web users to decide exactly when a given Web page should be retrieved and cached, thereby significantly improving Web users' ability to document Web contents.
    Type: Application
    Filed: July 30, 2001
    Publication date: January 30, 2003
    Inventor: Stefan Mark Elmer