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).

  • Patent number: 9927162
    Abstract: Embodiments generally relate to methods and apparatuses for generating ice. In one embodiment, a material is introduced to water, and the temperature of the combination of the water and the material is lowered until ice forms, the formed ice having a higher albedo than it would have had if the step of lowering the temperature had been carried out on the water without first carrying out the step of introducing the material. In one embodiment, the material is selected such that an aqueous solution of the material is alkaline. In another embodiment, a material is introduced to water, and the temperature of the combination of the water and the material is lowered until ice forms, the ice forming at a faster rate than the rate at which it would have formed if the material had not been introduced to the water.
    Type: Grant
    Filed: April 22, 2014
    Date of Patent: March 27, 2018
    Inventors: Leslie A Field, Susan J Strehlow, David G Duff, Kimberly M Wiefling
  • Patent number: 9376958
    Abstract: An electricity generation system (EGS) is provided that can be deployed at a point-of-use site (e.g. residence, business, etc.). In one implementation, the EGS includes a generator for generating electricity (where the generator includes a Stirling engine that uses gaseous fuel for a combustion fuel source), an interface for interfacing with an electrical infrastructure of the site as well as a power grid, and a controller for controlling the operation of the EGS. The EGS may be used in conjunction with the power grid, and may selectively provide electricity to the electrical infrastructure based upon instructions from a utility provider that manages the power grid, based upon an electrical load imposed on the electrical infrastructure, based upon the electrical capacity provided by the power grid, based upon cost considerations, etc. By taking some or all of these considerations into account, the EGS can adapt its behavior to fit changing conditions.
    Type: Grant
    Filed: March 14, 2013
    Date of Patent: June 28, 2016
    Inventors: Anthony Bonora, David G. Duff
  • Patent number: 9281690
    Abstract: A tactical smart grid system and method includes a plurality of energy generators and a plurality of loads, where the loads require energy from at least some of the energy generators. A plurality of interface units are provided, where each energy generator and load are connected to one of the plurality of interface units. Each of the interface units including a controller to thereby provide distributed intelligence and distributed system control, thereby removing the requirement of a centrally controlled system.
    Type: Grant
    Filed: December 21, 2010
    Date of Patent: March 8, 2016
    Assignee: Palo Alto Research Center Incorporated
    Inventors: Craig Eldershaw, David G. Duff
  • Publication number: 20150132474
    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: January 14, 2015
    Publication date: May 14, 2015
    Inventors: Craig Eldershaw, David G. Duff
  • Patent number: 8960120
    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: Grant
    Filed: December 9, 2008
    Date of Patent: February 24, 2015
    Assignee: Palo Alto Research Center Incorporated
    Inventors: Craig Eldershaw, David G. Duff
  • Publication number: 20140311178
    Abstract: Embodiments generally relate to methods and apparatuses for generating ice. In one embodiment, a material is introduced to water, and the temperature of the combination of the water and the material is lowered until ice forms, the formed ice having a higher albedo than it would have had if the step of lowering the temperature had been carried out on the water without first carrying out the step of introducing the material. In one embodiment, the material is selected such that an aqueous solution of the material is alkaline. In another embodiment, a material is introduced to water, and the temperature of the combination of the water and the material is lowered until ice forms, the ice forming at a faster rate than the rate at which it would have formed if the material had not been introduced to the water.
    Type: Application
    Filed: April 22, 2014
    Publication date: October 23, 2014
    Inventors: Leslie A. Field, Susan J. Strehlow, David G. Duff, Kimberly M. Wiefling
  • Patent number: 8624102
    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: Grant
    Filed: August 15, 2012
    Date of Patent: January 7, 2014
    Assignee: 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
  • Patent number: 8389851
    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: Grant
    Filed: October 21, 2010
    Date of Patent: March 5, 2013
    Assignees: Palo Alto Research Center Incorporated, SolFocus, Inc.
    Inventors: Hing Wah Chan, Harold Ackler, Scott E. Solberg, John S. Fitch, David K. Fork, David G. Duff, Michael C. Weisberg
  • Patent number: 8360423
    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: Grant
    Filed: September 15, 2011
    Date of Patent: January 29, 2013
    Assignee: Palo Alto Research Center Incorporated
    Inventors: David K. Biegelsen, David G. Duff, Lars E. Swartz, Ashish V. Pattekar
  • Publication number: 20120305405
    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: August 15, 2012
    Publication date: December 6, 2012
    Applicants: SolFocus, 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
  • Patent number: 8282097
    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: Grant
    Filed: September 15, 2011
    Date of Patent: October 9, 2012
    Assignee: Palo Alto Research Center Incorporated
    Inventors: David K. Biegelsen, David G. Duff, Erik L. Swartz, Ashish V. Pattekar
  • Publication number: 20120158196
    Abstract: A tactical smart grid system and method includes a plurality of energy generators and a plurality of loads, where the loads require energy from at least some of the energy generators. A plurality of interface units are provided, where each energy generator and load are connected to one of the plurality of interface units. Each of the interface units including a controller to thereby provide distributed intelligence and distributed system control, thereby removing the requirement of a centrally controlled system.
    Type: Application
    Filed: December 21, 2010
    Publication date: June 21, 2012
    Applicant: PALO ALTO RESEARCH CENTER INCORPORATED
    Inventors: Craig Eldershaw, David G. Duff
  • Publication number: 20120006655
    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: September 15, 2011
    Publication date: January 12, 2012
    Applicant: PALO ALTO RESEARCH CENTER INCORPORATED
    Inventors: David K. Biegelsen, David G. Duff, Lars E. Swartz, Ashish V. Pattekar
  • Publication number: 20120000386
    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: September 15, 2011
    Publication date: January 5, 2012
    Applicant: PALO ALTO RESEARCH CENTER INCORPORATED
    Inventors: David K. Biegelsen, David G. Duff, Lars E. Swartz, Ashish V. Pattekar
  • Patent number: 8042807
    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: Grant
    Filed: December 21, 2006
    Date of Patent: October 25, 2011
    Assignee: Palo Alto Research Center Incorporated
    Inventors: David K. Biegelsen, David G. Duff, Erik L. Swartz, Ashish V. Pattekar
  • Patent number: 8023866
    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: Grant
    Filed: July 31, 2008
    Date of Patent: September 20, 2011
    Assignee: Xerox Corporation
    Inventors: Meng H Lean, Shu Chang, Baomin Xu, Karl A Littau, David G Duff
  • Patent number: 7954449
    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: Grant
    Filed: May 8, 2007
    Date of Patent: June 7, 2011
    Assignee: Palo Alto Research Center Incorporated
    Inventors: David G. Duff, Craig Eldershaw
  • Patent number: 7945346
    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: Grant
    Filed: December 14, 2006
    Date of Patent: May 17, 2011
    Assignee: Palo Alto Research Center Incorporated
    Inventors: David K. Biegelsen, Bryan Preas, David G. Duff, Markus P. J. Fromherz, Craig Eldershaw, Lee Ackerson
  • Patent number: 7931269
    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: June 29, 2007
    Date of Patent: April 26, 2011
    Assignee: Palo Alto Research Center Incorporated
    Inventors: David G Duff, David K Biegelsen, Lars-Erik Swartz
  • Patent number: 7918453
    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: October 17, 2006
    Date of Patent: April 5, 2011
    Assignee: Palo Alto Research Center Incorporated
    Inventors: David G. Duff, David K. Biegelsen, Lars-Erik Swartz