Patents by Inventor David G. Duff

David G. Duff 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).

  • Publication number: 20110031211
    Abstract: A system may include an optical element including a surface defining a recess, conductive material disposed within the recess, and a solder mask disposed over a portion of the conductive material. The solder mask may define an aperture through which light from the optical element may pass. Some aspects provide creation of an optical element including a surface defining a recess, deposition of conductive material on the surface such that a portion of the deposited conductive material is disposed within the recess, and substantial planarization of the surface to expose the portion of the conductive material disposed within the recess.
    Type: Application
    Filed: October 21, 2010
    Publication date: February 10, 2011
    Inventors: Hing Wah Chan, Harold Ackler, Scott E. Solberg, John S. Fitch, David K. Fork, David G. Duff, Michael C. Weisberg
  • Patent number: 7885592
    Abstract: An apparatus is provided for clearing paper jams in a module along a print path of a printer, the module having nip baffles and a rotatable and removable core element defining a print path therethrough. The apparatus comprises at least one cam, a rotatable handle mechanism and a ramp drive mechanism to facilitate the paper jam clearing and removal of the core element from the module.
    Type: Grant
    Filed: June 29, 2007
    Date of Patent: February 8, 2011
    Assignee: Palo Alto Research Center Incorporated
    Inventors: Gregory P. Schmitz, David G. Duff
  • Publication number: 20100294364
    Abstract: A solar concentrator including a substantially-transparent optical element, a reflective material disposed on a convex surface of the optical element, an insulator layer on the reflective material, a conductive material that is thermal sprayed onto the insulator layer, and a solar cell mounted in a central region of the convex surface and electrically coupled to the conductive material. The optical element includes a flat surface disposed opposite to the convex surface and a concave surface defined in the flat surface. The convex surface and concave surface are arranged and the reflective material is deposited such that light passing through the flat surface is reflected by the reflective material toward the concave surface, and is re-reflected by the reflective material disposed on the concave surface onto an active surface of the solar cell. Thermal spraying the conductive material may include spraying a molten metal powder onto the insulator layer.
    Type: Application
    Filed: July 22, 2010
    Publication date: November 25, 2010
    Applicant: Palo Alto Research Center Incorporated
    Inventors: Hing Wah Chan, John S. Fitch, Michael C. Weisberg, David G. Duff
  • Patent number: 7811692
    Abstract: An improved fuel cell is described. The invention addresses the problem of mechanical failure in thin electrolytes. One embodiment varies the thickness of the electrolyte and positions at least either the anode or cathode in the recessed region to provide a short travel distance for ions traveling from the anode to the cathode or from the cathode to the anode. A second embodiment uses a uniquely shaped manifold cover to allow close positioning of the anode to the cathode. Using the described structures results in a substantial improvement in fuel cell reliability and performance.
    Type: Grant
    Filed: October 24, 2008
    Date of Patent: October 12, 2010
    Assignee: Palo Alto Research Center Incorporated
    Inventors: Raj B. Apte, David G. Duff, Christian G. Van de Walle, Jeng Ping Lu, Alberto Salleo, Stephen D. White
  • Publication number: 20100143581
    Abstract: A solar cell extrusion printing system includes a printhead assembly having one or more elongated valve structures that are adjustably disposed adjacent to the outlet orifices of selected nozzle channels, and a valve control device for controlling the position of the valve structures to facilitate controllable ink flow through selected nozzle channels of the printhead assembly during the gridline printing process. The printhead assembly defines an elongated opening (e.g., a slot or hole) that that intersects (i.e., passes through) each of the selected nozzle channels, and an elongated member is movably disposed in the slot and is selectively movable between a first (opened) position, in which the valve structure extrusion material is passed by the valve structure through the nozzle channel and out of the printhead, and a closed position, in which the extrusion material is blocked by the valve structure and prevented from passing through the nozzle channel.
    Type: Application
    Filed: December 9, 2008
    Publication date: June 10, 2010
    Applicant: Palo Alto Research Center Incorporated
    Inventors: Craig Eldershaw, David G. Duff
  • Publication number: 20100028054
    Abstract: A marking apparatus including a traveling wave grid toner transport circuit structure for transporting powdered toner along a transport surface, and electromechanical elements for selectively enabling toner patches to be projected to an output medium by a projecting electric field.
    Type: Application
    Filed: July 31, 2008
    Publication date: February 4, 2010
    Applicant: PALO ALTO RESEARCH CENTER INCORPORATED
    Inventors: Meng H. Lean, Shu Chang, Baomin Xu, Karl A. Littau, David G. Duff
  • Patent number: 7624981
    Abstract: In accordance with one aspect of the present exemplary embodiment, a universal interface is provided for operatively connecting and feeding sequential copy sheet output of various selectable first sheet processing machines to various selectable second sheet processing machines spaced apart horizontally or horizontally and vertically from the first sheet processing machines by widely varying ranges of horizontal distances. The universal interface includes a frame and a universal interface module providing a sheet feeding path repositionable relative to the frame therethrough, from one side to the other of the module, for transporting the copy sheet output of the first sheet processing machine to the copy sheet input of the second sheet processing machine. Further, the universal interface module includes an integral horizontally or horizontally and vertically repositionable sheet receiving and sheet discharging sheet path ends opening at opposite sides of the universal interface module.
    Type: Grant
    Filed: December 23, 2005
    Date of Patent: December 1, 2009
    Assignee: Palo Alto Research Center Incorporated
    Inventors: David K. Biegelsen, Lars-Erik Swartz, David G. Duff
  • Publication number: 20090047558
    Abstract: An improved fuel cell is described. The invention addresses the problem of mechanical failure in thin electrolytes. One embodiment varies the thickness of the electrolyte and positions at least either the anode or cathode in the recessed region to provide a short travel distance for ions traveling from the anode to the cathode or from the cathode to the anode. A second embodiment uses a uniquely shaped manifold cover to allow close positioning of the anode to the cathode. Using the described structures results in a substantial improvement in fuel cell reliability and performance.
    Type: Application
    Filed: October 24, 2008
    Publication date: February 19, 2009
    Applicant: Palo Alto Research Center Incorporated
    Inventors: Raj B. Apte, David G. Duff, Christian G. Van de Walle, Jeng Ping Lu, Alberto Salleo, Stephen D. White
  • Publication number: 20090025784
    Abstract: A system may include an optical element, a thermal-sprayed material disposed on the optical element, and a solar cell coupled to the optical element. Some aspects provide thermal spraying of a first material onto an optical element, and coupling of a solar cell to the optical element. Thermal spraying the first material may include spraying a molten metal powder onto the optical element.
    Type: Application
    Filed: July 24, 2007
    Publication date: January 29, 2009
    Applicants: SOL FOCUS, INC., PALO ALTO RESEARCH CENTER INCORPORATED
    Inventors: Hing Wah Chan, John S. Fitch, Michael C. Weisberg, David G. Duff
  • Publication number: 20090003878
    Abstract: An apparatus is provided for clearing paper jams in a module along a print path of a printer, the module having nip baffles and a rotatable and removable core element defining a print path therethrough. The apparatus comprises at least one cam, a rotatable handle mechanism and a ramp drive mechanism to facilitate the paper jam clearing and removal of the core element from the module.
    Type: Application
    Filed: June 29, 2007
    Publication date: January 1, 2009
    Inventors: Gregory P. Schmitz, David G. Duff
  • Patent number: 7459225
    Abstract: An improved fuel cell is described. The invention addresses the problem of mechanical failure in thin electrolytes. One embodiment varies the thickness of the electrolyte and positions at least either the anode or cathode in the recessed region to provide a short travel distance for ions traveling from the anode to the cathode or from the cathode to the anode. A second embodiment uses a uniquely shaped manifold cover to allow close positioning of the anode to the cathode. Using the described structures results in a substantial improvement in fuel cell reliability and performance.
    Type: Grant
    Filed: November 24, 2003
    Date of Patent: December 2, 2008
    Inventors: Raj B. Apte, David G. Duff, Christian G. Van de Walle, Jeng Ping Lu, Alberto Salleo, Stephen D. White
  • Publication number: 20080277885
    Abstract: A solar cell production system utilizes self-contained vacuum chucks that hold and cool solar cell wafers during transport on a conveyor between processing stations during a fabrication process. Each self-contained vacuum chuck includes its own local vacuum pump and a closed-loop cooling system. After each wafer is processed, it is removed from its vacuum chuck, and the vacuum chuck is returned to the start of the production line by a second conveyor belt. In one embodiment, each vacuum chuck includes an inductive power supply that is inductively coupled to an external source to drive that vacuum chuck's vacuum pump and cooling system. An optional battery is recharged by the inductive power supply, and is used to power the vacuum pump and cooling system during hand-off between adjacent processing stations.
    Type: Application
    Filed: May 8, 2007
    Publication date: November 13, 2008
    Applicant: Palo Alto Research Center Incorporated
    Inventors: David G. Duff, Craig Eldershaw
  • Publication number: 20080186593
    Abstract: A system may include an optical element including a surface defining a recess, conductive material disposed within the recess, and a solder mask disposed over a portion of the conductive material. The solder mask may define an aperture through which light from the optical element may pass. Some aspects provide creation of an optical element including a surface defining a recess, deposition of conductive material on the surface such that a portion of the deposited conductive material is disposed within the recess, and substantial planarization of the surface to expose the portion of the conductive material disposed within the recess.
    Type: Application
    Filed: July 24, 2007
    Publication date: August 7, 2008
    Applicants: SOL FOCUS, INC., PALO ALTO RESEARCH CENTER INCORPORATED
    Inventors: Hing Wah Chan, Harold Ackler, Scott E. Solberg, John S. Fitch, David K. Fork, David G. Duff, Michael C. Weisberg
  • Publication number: 20080150229
    Abstract: A transport system for cut sheet media has a first and second cylinder to form a nip, a support subsystem to transport edges of cut sheets having at least one image into and out of the nip, and an array of contact points on each cylinder to make contact with the cut sheets without marking the image. A wheel for a print medium transport system has an outer rim having a series of contact points, an inner hub supporting a means to accommodate a drive shaft, and an internal spring connecting the outer rim to the inner hub. A method of transporting cut sheets in a printing system forms a nip between at least one pair of cylinders, each cylinder having an array of contact points, guides a first edge of a cut sheet into the nip, and uses the arrays of contact points to transport the cut sheets through one of either a fusing or drying process.
    Type: Application
    Filed: December 21, 2006
    Publication date: June 26, 2008
    Applicant: PALO ALTO RESEARCH CENTER INCORPORATED
    Inventors: David K. Biegelsen, David G. Duff, Lars E. Swartz, Ashish V. Pattekar
  • Publication number: 20080147234
    Abstract: A configurable self-identifying workpiece transport system is described for moving an associated workpiece relative to a plurality of associated workpiece functional units selectively performing operations on the associated workpiece. The transport system includes a plurality of transport modules and a control unit. The plurality of transport modules are disposed in selected positions relative to the associated workpiece functional units, and each of the plurality of transport modules stores identification data and functionality data specific to the transport module. The control unit includes an automatic identification system in communication with each of the plurality of transport modules for retrieving the identification data and the functionality data from each of the plurality of transport modules and generating an itinerary for moving the associated workpiece relative to the workpiece functional units.
    Type: Application
    Filed: December 14, 2006
    Publication date: June 19, 2008
    Inventors: David K. Biegelsen, Bryan Preas, David G. Duff, Markus P.J. Fromherz, Craig Eldershaw, Lee Ackerson
  • Publication number: 20070296143
    Abstract: A media path jam clearance apparatus installable in a supporting structure includes media drive mechanisms for moving flexible media through media paths and a rotatable, removable jam clearance element. Within the jam clearance element facing surfaces of guide elements define guide surfaces for media paths, with the guide elements having external surfaces capable of supporting the flexible media as it is wrapped around the external surfaces. A pivotal support element supports and enables rotational movement of the jam clearance element within the supporting structure. The jam clearance element may be partially or entirely extracted from the supporting structure.
    Type: Application
    Filed: June 29, 2007
    Publication date: December 27, 2007
    Applicant: PALO ALTO RESEARCH CENTER INCORPORATED
    Inventors: David G. Duff, David K. Biegelsen, Lars-Erik Swartz
  • Patent number: 7185888
    Abstract: A media path jam clearance apparatus installable in a supporting structure includes media drive mechanisms for moving flexible media through media paths and a rotatable, removable jam clearance element. Within the jam clearance element facing surfaces of guide elements define guide surfaces for media paths, with the guide elements having external surfaces capable of supporting the flexible media as it is wrapped around the external surfaces. A pivotal support element supports and enables rotational movement of the jam clearance element within the supporting structure. The jam clearance element may be partially or entirely extracted from the supporting structure.
    Type: Grant
    Filed: March 29, 2004
    Date of Patent: March 6, 2007
    Assignee: Palo Alto Research Center Incorporated
    Inventors: David G. Duff, David K. Biegelsen, Lars-Erik Swartz
  • Patent number: 7108260
    Abstract: A flexible media transport system includes a director element having articulating tips that provide access to selected media paths. The director element(s) can be incorporated into a director module. Multiple director modules can then be combined into a highly flexible and reconfigurable media transport system. By implementing the joints between the articulating tips and the body of the director element such that a continuous surface is provided in the path of the flexible media, stubbing of the moving media can be avoided. The continuous-surface joint interface can be provided via flexible skins, monolithic articulating tip-director element structures, and preconfigured resilient plate structures, among others.
    Type: Grant
    Filed: December 19, 2003
    Date of Patent: September 19, 2006
    Assignee: Palo Alto Research Center Incorporated
    Inventors: David K. Biegelsen, Lars-Erik Swartz, David G. Duff, Mark H. Yim
  • Patent number: 6842246
    Abstract: An alignment system includes a first module having a plurality of emitters and a first receiver configuration located on the face of the first module. A second module has a second plurality of emitters and a second receiver configuration located on the face of the second module. First and second trigger signal generators fire the first and second plurality of the emitters. The generated signals are sensed by at least some of the receivers. A converter arrangement obtain and convert the received signals into digital data representative of the readings received by selected receivers. A processing system computes at least one of an absolute six degree offset or a relative six degree offset between the faces. The offset information is then used to achieve a desired alignment between the face of the first module and the face of the second module.
    Type: Grant
    Filed: December 10, 2001
    Date of Patent: January 11, 2005
    Assignee: Xerox Corporation
    Inventors: Kimon D. Roufas, Ying Zhang, David G. Duff, Mark H. Yim, Craig Eldershaw
  • Patent number: 6605914
    Abstract: A robotic module for a toy construction system includes a housing enclosing a gear mechanism and an actuator connected to a pivot mechanism to supply operational power for rotation. An energy storage device supplies power to the actuator, which rotates in response to instructions received from a control unit connected to the actuator. A connection plate forms a connection between at least two of the modules. At least one position sensor is provided to sense the arrangement of the modules connected together.
    Type: Grant
    Filed: August 24, 2001
    Date of Patent: August 12, 2003
    Assignee: Xerox Corporation
    Inventors: Mark H. Yim, David G. Duff, Samuel B. Homans, Kimon D. Roufas, John W. Suh