Patents by Inventor John B. Dunn

John B. Dunn 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: 6077081
    Abstract: A firefighting training apparatus is provided for simulating the pumping of water through various long lengths of hose to train firefighters to deliver a proper amount of water through the fire hose. The apparatus includes a disk having one or more apertures therethrough. The one or more apertures permit the passage of water through the disk while providing resistance to the water to simulate the resistance encounted by water flowing through a long length of fire hose. The firefighting training apparatus is used by placing the disk within the flow of water through the fire hose. A firefighter can practice delivering a proper amount of water through a fire hose to a nozzle without the need of using a long length of fire hose.
    Type: Grant
    Filed: July 11, 1997
    Date of Patent: June 20, 2000
    Inventor: John B. Dunn
  • Patent number: 5572996
    Abstract: This invention describes a method for the accurate and sensitive measurement of an exogenous fluorescence chromophore in vivo. The method provides a means for normalizing a typical endogenous fluorescence signal into a relatively narrow band of values for different tissue types. The method employs irradiation of a target tissue at a single excitation wavelength while measuring two narrow bands of emission wavelengths, one of which is principally associated with the endogenous autofluorescence of the tissue while the other is chosen to be characteristic of the exogenous chromophore of interest. An exogenous chromophore is administered to a target tissue in vivo. A fiber optic positioned near the target tissue delivers illuminating excitation light from a light source to the tissue and receives fluorescence light from both exogenous and endogenous chromophores in the tissue and conducts the fluorescence light to a detector.
    Type: Grant
    Filed: January 17, 1996
    Date of Patent: November 12, 1996
    Assignee: PDT Systems, Inc.
    Inventors: Daniel R. Doiron, John B. Dunn
  • Patent number: 5251004
    Abstract: An improved power meter for measuring the energy and wavelength of light emanating from an optical fiber. The meter is an integrating sphere having a source aperture for receiving the tip of an optical fiber and coupling the light from the tip into the sphere's central cavity. The source aperture is modified to include a sterilizable, liquid-fillable insert which mimics the optical environment within tissue. The sphere also has improved baffling and the sensitivity of wavelength verification is improved by means of a rotatable interference filter placed between an exit aperture and a light detector.
    Type: Grant
    Filed: March 13, 1992
    Date of Patent: October 5, 1993
    Assignee: PDT Systems, Inc.
    Inventors: Daniel R. Doiron, Paul M. Paspa, John B. Dunn
  • Patent number: 5153612
    Abstract: A flexible reservoir bladder is connected to the base of a pen body to define a reservoir volume that permits nearly all of the ink contained therein to be delivered from the pen by a print head. The back pressure developed within the reservoir volume is regulated by the resilient properties of the bladder and an orifice that permits controlled entry of air into the volume as the ink is depleted. The system is able to withstand severe environmental effects, such as a drop in ambient air pressure, while preventing pen leakage.
    Type: Grant
    Filed: January 3, 1991
    Date of Patent: October 6, 1992
    Assignee: Hewlett-Packard Company
    Inventors: John B. Dunn, Bruce Cowger
  • Patent number: 5103246
    Abstract: A X-Y multiplex drive circuit and associated ink feed arrangement for an ink jet printhead wherein resistive heater elements, X-Y electrical interconnects thereto and closely adjacent ink feed ports are integrated on or within a given printhead substrate surface area with a maximum packing density and a minimum of fluidic crosstalk. Ink feed channels are formed within a printhead barrier layer which separates an ink jet orifice plate from an underlying printhead substrate, and state-of-the-art MOS planar processes and thin film deposition processes may be used for fabricating this drive circuit and its associated ink feed arrangement.
    Type: Grant
    Filed: February 15, 1991
    Date of Patent: April 7, 1992
    Assignee: Hewlett-Packard Company
    Inventor: John B. Dunn
  • Patent number: 5040001
    Abstract: An improved ink storage system for ink cartridges which allows operation in a rapid and continuous manner while avoiding deprimes. A flexible, resilient ink bladder is provided which consists of an elongate reservoir that is closed at the bottom and open at the top with a tubular side wall therebetween. The bladder is supplied with ink, and a negative pressure is maintained therein. Due to the negative pressure, the side wall collapses inwardly upon ink delivery. To ensure that the wall collapses properly, the bladder is designed so the side wall thickness varies, with some portions of the wall being thinner than others. As a result, the thinner portions collapse inwardly toward the thicker portions during ink delivery. This prevents undesired increases in back-pressure within the bladder, thereby eliminating ink cartridge deprimes.
    Type: Grant
    Filed: June 27, 1990
    Date of Patent: August 13, 1991
    Assignee: Hewlett-Packard Company
    Inventors: John B. Dunn, Douglas J. Ullmer, Elwood H. Barlow, Gregory P. Merten