Patents Represented by Attorney, Agent or Law Firm William W. Propp
  • Patent number: 6631009
    Abstract: A document printing system involves multi-threaded processing of a document object. A deadlock situation between a preprocessing thread and a cancellation thread can be averted with a time-out locking mechanism. After the cancellation thread has locked the document object, its sets a cancel flag, then waits for preprocessing to complete. Meanwhile, the preprocessing thread may request a lock of the document object. If so, it will specify a maximum time-out period. After expiration of the time-out period, a timed-out status response will be sent from the document object to the preprocessing thread. The preprocessing thread will then poll the document object for a cancel flag. A cancel flag will be set on the document object only if the cancellation thread has requested the document object perform a cancellation operation. If there is no cancel flag, the preprocessing thread will again request a lock of the document object with a maximum time-out period.
    Type: Grant
    Filed: September 24, 1999
    Date of Patent: October 7, 2003
    Assignee: Xerox Corporation
    Inventors: Jennifer D. Thomas, David P. Nesbitt
  • Patent number: 6219168
    Abstract: A single rotating polygon mirror with adjacent facets having different tilt angles reflects and splits the scanning beam to multiple photoreceptors in a raster output scanning (ROS) system. The mirror can have two or four alternating facets with different tilt angles. Two different light beams form two different light sources can be reflected and split from the polygon mirror contemporaneously to multiple photoreceptors. The split beams from the polygon mirror facets can share a common f-theta scan lens.
    Type: Grant
    Filed: December 20, 1999
    Date of Patent: April 17, 2001
    Assignee: Xerox Corporation
    Inventor: Mark Shi Wang
  • Patent number: 5907160
    Abstract: A thin film organic light emitting diode with edge emitter waveguide comprises, in sequence, a substrate, a waveguide, an anode, a hole transport layer, an electroluminescent layer, and a cathode. Voltage applied between the anode and cathode causes the electroluminescent layer to emit light through the hole transport layer and the anode into the waveguide where the light is internally reflected within the waveguide and propagates through the length of the waveguide to be emitted through the edge of the waveguide. The non-emission edge of the waveguide may be sloped with a conductor layer to the anode and a conductor layer to the cathode forming a reflective surface to the non-emission edge.
    Type: Grant
    Filed: December 20, 1996
    Date of Patent: May 25, 1999
    Assignee: Xerox Corporation
    Inventors: James M. Wilson, Jean-Michel Guerin