Patents by Inventor David J. Waller

David J. Waller 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: 6428156
    Abstract: An actively-controlled recirculating ink delivery system is provided that incorporates active control of pressures downstream of the printhead. This is achieved through the use of a device (such as a pump, return valve, combination thereof or similar devices) that provides active control of downstream ink pressures. A pressurized ink supply, pressure sensors, an air and heat exchanger are also provided, thereby improving start up, normal operation, purging and shut down procedures. Because the pressurized ink supply is not restricted to sit at a particular vertical distance below the printhead, backpressure may be changed quickly and easily through electronic control, and system priming is considerably quicker than with conventional air-pressurized systems.
    Type: Grant
    Filed: November 2, 1999
    Date of Patent: August 6, 2002
    Assignee: Hewlett-Packard Company
    Inventors: David J. Waller, Melissa D. Boyd, John M. Koegler, III
  • Patent number: 6354694
    Abstract: A method and apparatus for improving ink-jet print quality uses a print head having an array using a plurality of nozzles in sets in each drop generator mechanism. Where a conventional ink-jet pen fires a single droplet of ink at a pixel per firing cycle, the present invention fires a plurality of droplets at different subdivisions of pixels. The particular array design may vary from ink-to-ink or pen-to-pen. Each drop generator of a print head array includes a plurality of nozzles wherein each of the nozzles has an exit orifice with an areal dimension, and produces an ink droplet that produces a dot on adjacent print media wherein the dot has an areal dimension, less than the areal dimension of a pixel to be printed. Dots are printed in a pattern for each pixel wherein print quality is achieved that approximates a higher resolution print made by conventional ink-jet methodologies.
    Type: Grant
    Filed: February 19, 1999
    Date of Patent: March 12, 2002
    Assignee: Hewlett-Packard Company
    Inventors: Timothy L. Weber, John P. Harmon, S. Dana Seccombe, Colin C. Davis, Paul J. McClellan, David J. Waller
  • Patent number: 6309054
    Abstract: Pillars are formed in a fully integrated thermal inkjet printhead to prevent particles from entering into a nozzle chamber along an ink refill channel. The pillars are formed after a step of applying a thin film structure to a substrate. At one step, pits are etched through the thin film structure. At another step, material for an orifice layer is deposited into the pits. At another step, a firing chamber is etched into the orifice layer. At another step, a trench is etched into the backside of the wafer in the vicinity of the filled pits. The material filling each pit is not removed and remains in place to define the respective pillars. Two or more pillars are formed within the trench for each inkjet nozzle chamber. Alternatively pillars are formed by depositing material into the underside trench and performing photoimaging processes.
    Type: Grant
    Filed: October 23, 1998
    Date of Patent: October 30, 2001
    Assignee: Hewlett-Packard Company
    Inventors: Naoto Kawamura, David R Thomas, David J Waller, Timothy L Weber
  • Patent number: 6250738
    Abstract: An inkjet printing system includes a scalable printhead with an ink manifold. The scalable printhead is formed by mounting an ink manifold and multiple thermal inkjet printhead dies to a carrier substrate. The carrier substrate is machined to include through-slots. There is a through-slot for each refill slot among the multiple printhead dies. A first end of a given through-slot connects to a refill slot of a corresponding printhead die. An opposite, second end of the through-slot connects to the ink manifold. The ink manifold includes an inlet for coupling to an ink supply reservoir. The ink manifold also includes one or more channels and a plurality of feed openings. Each feed opening connects to a printhead die refill slot by way of a substrate through-slot.
    Type: Grant
    Filed: December 17, 1998
    Date of Patent: June 26, 2001
    Assignee: Hewlett-Packard Company
    Inventors: David J Waller, Timothy E Beerling, Melissa D Boyd, James W Pearson, Marvin G Wong
  • Patent number: 6155670
    Abstract: A method and apparatus for improving inkjet print quality uses a printhead having an array using a plurality of nozzles in sets in each drop generator mechanism. Where a conventional inkjet pen fires a single droplet of ink at a target pixel per firing cycle, the present invention simultaneously ejects a plurality of droplets at different subdivisions of pixels. Drop generators of a printhead array includes a plurality of nozzles for the drop generators arranged such that the light absorption of the sum of the simultaneously ejected ink droplets is like that of conventionally ejected drops but distributed over an area of the printed medium greater than that of a conventional target pixel.
    Type: Grant
    Filed: January 29, 1999
    Date of Patent: December 5, 2000
    Assignee: Hewlett-Packard Company
    Inventors: Timothy L. Weber, John P. Harmon, S. Dana Seccombe, Colin C. Davis, Paul J. McClellan, David J. Waller
  • Patent number: 6099108
    Abstract: A method and apparatus for improving ink-jet print quality uses a print head having an array using a plurality of nozzles in sets in each drop generator mechanism. Where a conventional ink-jet pen fires a single droplet of ink at a pixel per firing cycle, the present invention fires a plurality of droplets at different subdivisions of pixels. The particular array design may vary from ink-to-ink or pen-to-pen. Each drop generator of a print head array includes a plurality of nozzles wherein each of the nozzles has an exit orifice with an areal dimension, and produces an ink droplet that produces a dot on adjacent print media wherein the dot has an areal dimension, less than the areal dimension of a pixel to be printed. Dots are printed in a pattern for each pixel wherein print quality is achieved that approximates a higher resolution print made by conventional ink-jet methodologies.
    Type: Grant
    Filed: March 5, 1997
    Date of Patent: August 8, 2000
    Assignee: Hewlett-Packard Company
    Inventors: Timothy L. Weber, John Paul Harmon, S. Dana Seccombe, Colin C. Davis, Paul J. McClellan, David J. Waller
  • Patent number: 6003977
    Abstract: The configuration of an ink inlet through which flows ink into a chamber for expulsion from the chamber by a thermal process is such that a vapor bubble generated by the thermal process to eject ink from the chamber expands to simultaneously occlude the inlet, thereby to separate the ink within the chamber from ink within a channel that is in fluid communication with the inlet. The separation eliminates a liquid path between the chamber and the channel so that substantially no ink is blown back into the channel as the bubble expands, thereby improving the thermal efficiency of the process.
    Type: Grant
    Filed: July 30, 1996
    Date of Patent: December 21, 1999
    Assignee: Hewlett-Packard Company
    Inventors: Timothy L. Weber, David J. Waller, Kenneth E. Trueba, David Thomas
  • Patent number: 5988786
    Abstract: An orifice membrane is provided an articulation parallel to the rows of orifices and between the area of the orifice membrane secured to the cartridge body and the area of the orifice membrane secured to the barrier layer of the heater resistor substrate. The reduced stress at the orifices reduces the distortion of the bore axis of the orifices.
    Type: Grant
    Filed: June 30, 1997
    Date of Patent: November 23, 1999
    Assignee: Hewlett-Packard Company
    Inventors: David J. Waller, Timothy L. Weber, Kenneth E. Trueba, Hai Q. Tran
  • Patent number: 5969736
    Abstract: A pressure regulator that sets the pressure of a liquid to a predetermined pressure differential below a reference pressure, such as atmospheric pressure. The pressure regulator comprises a liquid delivery channel and a capillary array. The liquid delivery channel includes a liquid input and a liquid output. The liquid flows through the liquid delivery channel from the liquid input to the liquid output. The capillary array is composed of ones of an elongate capillary. The capillary includes a first end in fluid communication with the liquid delivery channel and a second end in pressure communication with a source of the reference pressure. The liquid flows through the first end into the capillary to form a liquid surface in the capillary. The second end is remote from the first end.
    Type: Grant
    Filed: July 14, 1998
    Date of Patent: October 19, 1999
    Assignee: Hewlett-Packard Company
    Inventors: Leslie A. Field, Phillip Barth, David J. Waller, George D. Zuras, Jr., Paul P. Merchant, Storrs Hoen, Channing R. Robertson