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David G. Duff

David G. Duff, Portola Valley, CA US

Patent application numberDescriptionPublished
20090025784THERMAL SPRAY FOR SOLAR CONCENTRATOR FABRICATION - 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.01-29-2009
20090047558MICRO-MACHINED FUEL CELLS - 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.02-19-2009
20100028054POWDERED TONER DIRECT MARKING APPARATUS - 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.02-04-2010
20100143581Micro-Extrusion Printhead With Nozzle Valves - 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.06-10-2010
20100294364Thermal Spray For Solar Concentrator Fabrication - 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.11-25-2010
20110031211Metal Trace Fabrication For Optical Element - 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.02-10-2011

Patent applications by David G. Duff, Portola Valley, CA US

David G. Duff, Portola, CA US

Patent application numberDescriptionPublished
20090003878Rotary operated mechanism for retracting paper pathways of printers - 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.01-01-2009

David G. Duff, Woodside, CA US

Patent application numberDescriptionPublished
20080277885Wiring-Free, Plumbing-Free, Cooled, Vacuum Chuck - 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.11-13-2008

Patent applications by David G. Duff, Woodside, CA US