Patents by Inventor Gerald E. Duffy

Gerald E. Duffy 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: 7091670
    Abstract: A safety interlock apparatus for an electrical device includes a DC power supply, a ballast power supply including a ballast control circuit that controls a ballast power circuit, and a lamp. A relatively low voltage electrical connection is present between the DC power supply and the ballast control circuit. A relatively high voltage electrical connection is present between the lamp and the ballast power circuit. A safety interlock switch is positioned on the relatively low voltage electrical connection, the switch having a closed state wherein the relatively low voltage is supplied to the ballast control circuit and an open disconnected state wherein the relatively low voltage electrical connection is disconnected. A panel is fixable to the electrical device frame, and is selectively movable to expose the lamp for removal.
    Type: Grant
    Filed: September 13, 2004
    Date of Patent: August 15, 2006
    Assignee: InFocus Corporation
    Inventors: Henry Frazier Pruett, Gerald E. Duffy
  • Patent number: 6853152
    Abstract: A safety interlock apparatus for an electrical device includes a DC power supply, a ballast power supply including a ballast control circuit that controls a ballast power circuit, and a lamp. A relatively low voltage electrical connection is present between the DC power supply and the ballast control circuit. A relatively high voltage electrical connection is present between the lamp and the ballast power circuit. A safety interlock switch is positioned on the relatively low voltage electrical connection, the switch having a closed state wherein the relatively low voltage is supplied to the ballast control circuit and an open disconnected state wherein the relatively low voltage electrical connection is disconnected. A panel is fixable to the electrical device frame, and is selectively movable to expose the lamp for removal.
    Type: Grant
    Filed: July 1, 2002
    Date of Patent: February 8, 2005
    Assignee: InFocus Corporation
    Inventors: Henry Frazier Pruett, Gerald E. Duffy
  • Publication number: 20030057849
    Abstract: A safety interlock apparatus for an electrical device includes a DC power supply, a ballast power supply including a ballast control circuit that controls a ballast power circuit, and a lamp. A relatively low voltage electrical connection is present between the DC power supply and the ballast control circuit. A relatively high voltage electrical connection is present between the lamp and the ballast power circuit. A safety interlock switch is positioned on the relatively low voltage electrical connection, the switch having a closed state wherein the relatively low voltage is supplied to the ballast control circuit and an open disconnected state wherein the relatively low voltage electrical connection is disconnected. A panel is fixable to the electrical device frame, and is selectively movable to expose the lamp for removal.
    Type: Application
    Filed: July 1, 2002
    Publication date: March 27, 2003
    Inventors: Henry Frazier Pruett, Gerald E. Duffy
  • Patent number: 6424097
    Abstract: A safety interlock apparatus for an electrical device includes a DC power supply, a ballast power supply including a ballast control circuit that controls a ballast power circuit, and a lamp. A relatively low voltage electrical connection is present between the DC power supply and the ballast control circuit. A relatively high voltage electrical connection is present between the lamp and the ballast power circuit. A safety interlock switch is positioned on the relatively low voltage electrical connection, the switch having a closed state wherein the relatively low voltage is supplied to the ballast control circuit and an open disconnected state wherein the relatively low voltage electrical connection is disconnected. A panel is fixable to the electrical device frame, and is selectively movable to expose the lamp for removal.
    Type: Grant
    Filed: May 12, 2000
    Date of Patent: July 23, 2002
    Assignee: InFocus Corporation
    Inventors: Henry Frazier Pruett, Gerald E. Duffy
  • Patent number: 5793352
    Abstract: The present invention includes a multimedia projection system coupling apparatus having a coupling converter for interconnecting at least one multimedia source and a multimedia projection display system. The coupler system includes at least two source cables that extend from the multimedia source and carry to the coupling converter media signals corresponding to different media, such as video and system control. The coupling converter delivers corresponding media signals to a projector terminal from which a projector cable extends to the projection display system. In the preferred embodiment, the coupling converter includes signal format conversion circuitry for converting each media signal or its component to a differential signal format, and the projector cable preferably includes a separate twisted pair of wires for carrying each of the differential format signals.
    Type: Grant
    Filed: March 7, 1996
    Date of Patent: August 11, 1998
    Assignee: In Focus Systems, Inc.
    Inventors: Robert Y. Greenberg, Jorell A. Olson, Gerald E. Duffy, Mark E. Schoening
  • Patent number: 5719463
    Abstract: A metal halide arc discharge lamp includes a sealed outer envelope, an arc tube located within the envelope, a cylindrical shroud positioned around the arc tube, stops positioned at ends of the shroud to capture the shroud therebetween, conduction wires which both provide electrical energy to the arc tube and mechanically support the arc tube and the shroud, and a compression spring secured by an eyelet for removing tension loading from the arc tube.
    Type: Grant
    Filed: June 3, 1996
    Date of Patent: February 17, 1998
    Assignee: General Electric Company
    Inventors: Martin N. Hassink, Gerald E. Duffy
  • Patent number: 5594294
    Abstract: A lamp assembly having an improved mounting arrangement for a light source and shroud configuration provides for such improved mounting arrangement in a manner such that manufacturing of the lamp assembly is simplified and the light source is protected against vibration and shock forces during manufacture and operation. The light source includes an arc tube which is under pressure and which is disposed within a shroud member that is then mounted within an outer lamp envelope. Top and bottom support members made of an insulative material are disposed on opposite ends of the shroud member. One of the lead wires used to couple energy to the light source, extends through the shroud member and has an insulative sleeve disposed in surrounding relation to a portion thereof. As the one lead wire extends through a hole formed in the bottom support member, a resilient clip member is slid over the bottom portion of such lead wire.
    Type: Grant
    Filed: October 31, 1994
    Date of Patent: January 14, 1997
    Assignee: General Electric Company
    Inventors: Gerald E. Duffy, John J. Cowling, D. Aaron Crites, Dale K. Mikol
  • Patent number: 5479102
    Abstract: A simulated load circuit for measuring the impedance of the arc discharge of an electrodeless discharge lamp of the type having an arc tube and an excitation coil for exciting the arc discharge in an ionizable fill contained therein includes: a secondary coil spaced apart from the excitation coil by a distance which is varied in order to vary the coupling coefficient between the secondary coil and the excitation coil; a fixed load resistance coupled to the secondary coil; and a variable matching network coupled in series or parallel with the load resistance, the impedance of the matching network being varied in order to vary the ratio of reactance to resistance of the load circuit. The distance between the secondary coil and the excitation coil is varied, and the impedance of the matching network is varied, until the input impedance of the load circuit is substantially equivalent to the operating impedance of the lamp.
    Type: Grant
    Filed: April 19, 1994
    Date of Patent: December 26, 1995
    Assignee: General Electric Company
    Inventors: Sayed-Amr A. El-Hamamsy, Michael M. Secen, Mark E. Duffy, Gerald E. Duffy
  • Patent number: 5332970
    Abstract: A simulated load circuit for measuring the impedance of the arc discharge of an electrodeless discharge lamp of the type having an arc tube and an excitation coil for exciting the arc discharge in an ionizable fill contained therein includes: a secondary coil spaced apart from the excitation coil by a distance which is varied in order to vary the coupling coefficient between the secondary coil and the excitation coil; a fixed load resistance coupled to the secondary coil; and a variable matching network coupled in series or parallel with the load resistance, the impedance of the matching network being varied in order to vary the ratio of reactance to resistance of the load circuit. The distance between the secondary coil and the excitation coil is varied, and the impedance of the matching network is varied, until the input impedance of the load circuit is substantially equivalent to the operating impedance of the lamp.
    Type: Grant
    Filed: June 25, 1992
    Date of Patent: July 26, 1994
    Assignee: General Electric Company
    Inventors: Sayed-Amr A. El-Hamamsy, Michael M. Secen, Mark E. Duffy, Gerald E. Duffy
  • Patent number: 5204578
    Abstract: Heat sink means are provided for a metal halide lamp to enable more light output during lamp start-up. A xenon-metal halide lamp employing the heat sink means is disclosed along an with automotive headlamp having this lamp for its light source.
    Type: Grant
    Filed: May 15, 1992
    Date of Patent: April 20, 1993
    Assignee: General Electric Company
    Inventors: Timothy P. Dever, Gary R. Allen, John M. Davenport, Gerald E. Duffy
  • Patent number: 5107165
    Abstract: Anode and cathode means are provided for a metal halide lamp which cooperate in providing more rapid light output during lamp start-up. A xenon-metal halide lamp employing the improved discharge electrode means is disclosed along with an automotive headlamp having this lamp for its light source.
    Type: Grant
    Filed: November 1, 1990
    Date of Patent: April 21, 1992
    Assignee: General Electric Company
    Inventors: Timothy P. Dever, Gary R. Allen, John M. Davenport, Gerald E. Duffy