Patents by Inventor Charles David Greskovich

Charles David Greskovich 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: 7297037
    Abstract: A ceramic discharge chamber for a lamp, according to an exemplary embodiment of the invention, comprises a first member which includes a leg portion and a transition portion, wherein the leg portion and the transition portion are integrally formed as one piece from a ceramic material, and a second member which includes a body portion, wherein the body portion is bonded to the transition portion of the first member. The ceramic discharge chamber can be formed by injection molding a ceramic material to form the first member, the first member forming a first portion of the ceramic discharge chamber; and bonding the first member to a second member which forms a second portion of the ceramic discharge chamber.
    Type: Grant
    Filed: June 18, 2004
    Date of Patent: November 20, 2007
    Assignee: General Electric Company
    Inventors: Venkat Subramaniam Venkataramani, Charles David Greskovich, Curtis Edward Scott, James Anthony Brewer
  • Patent number: 7098460
    Abstract: A conversion device for use in an imaging system is provided. The conversion device includes a first perforated plate portion forming a plurality of collimator channels separated by a plurality of thin collimator walls. A second perforated plate portion forming a plurality of scintillator channels separated by a plurality of thin scintillator walls is attached to the first perforated plate portion. A reflective coating is applied to the inside scintillator surface of the plurality of thin scintillator walls. A scintillator material is filled into the plurality of scintillator channels.
    Type: Grant
    Filed: August 4, 2003
    Date of Patent: August 29, 2006
    Assignee: General Electric Company
    Inventors: Robert Joseph Lyons, Martin Kin-Fei Lee, Venkat Subramaniam Venkataramani, Clifford Bueno, James Walter LeBlanc, James Scott Vartuli, Charles David Greskovich, Stephen F. Bancheri
  • Patent number: 7019284
    Abstract: A system for use in oil drilling applications includes a scintillator material having a cubic garnet host and praseodymium distributed within the host. The scintillator material emits ultraviolet radiation in response to stimulating gamma ray radiation. A radiation detector optically coupled to the scintillator detects the emitted ultraviolet radiation. In a method for detecting oil, a radiation detector is optically coupled to a scintillator material having a cubic garnet host and praseodymium distributed within the host, wherein the praseodymium acts as an activator, and wherein the scintillator material emits ultraviolet radiation in response to stimulating gamma ray radiation. The detector and the scintillator material are lowered below the surface of the earth, and ultraviolet radiation emitted by the scintillator material in response to stimulating gamma ray radiation reflected by hydrogen bearing compounds indicating the presence of oil is detected by the detector.
    Type: Grant
    Filed: July 11, 2003
    Date of Patent: March 28, 2006
    Assignee: General Electric Company
    Inventors: Alok Mani Srivastava, Holly Ann Comanzo, Charles David Greskovich
  • Publication number: 20040256994
    Abstract: A ceramic discharge chamber for a lamp, according to an exemplary embodiment of the invention, comprises a first member which includes a leg portion and a transition portion, wherein the leg portion and the transition portion are integrally formed as one piece from a ceramic material, and a second member which includes a body portion, wherein the body portion is bonded to the transition portion of the first member. The ceramic discharge chamber can be formed by injection molding a ceramic material to form the first member, the first member forming a first portion of the ceramic discharge chamber; and bonding the first member to a second member which forms a second portion of the ceramic discharge chamber. The members which form the ceramic discharge chamber can greatly facilitate assembly of the discharge chamber, because the discharge chamber can be constructed with only one or two bonds between the members.
    Type: Application
    Filed: June 18, 2004
    Publication date: December 23, 2004
    Inventors: Venkat Subramaniam Venkataramani, Charles David Greskovich, Curtis Edward Scott, James Anthony Brewer
  • Patent number: 6793848
    Abstract: The present invention provides terbium or lutetium garnet x ray scintillators activated with a rare earth metal ion, such as cerium, and treated by annealing in a controlled atmosphere comprising a predetermined amount of oxygen for a predetermined time and temperature to reduce radiation damage that would otherwise occur when the scintillator material is exposed to high energy radiation, such as the type of radiation required to use the scintillator for medical radiographic imaging and the like. In an embodiment, a single crystal or a polycrystalline scintillator comprising the general formula (Tb1−xLuxCey)3Al5O12 (where 0<×≦0.5, and y is in the range from about 0.0005 to about 0.2, and annealed at 1400° C. to 1500° C. in a controlled atmosphere comprising 1×10−6 to 0.22 atm oxygen shows an increased resistance to radiation damage.
    Type: Grant
    Filed: December 10, 2002
    Date of Patent: September 21, 2004
    Assignee: General Electric Company
    Inventors: James Scott Vartuli, Steven Jude Ductos, Robert Joseph Lyons, Charles David Greskovich
  • Patent number: 6791266
    Abstract: A ceramic discharge chamber for a lamp, according to an exemplary embodiment of the invention, comprises a first member which includes a leg portion and a transition portion, wherein the leg portion and the transition portion are integrally formed as one piece from a ceramic material, and a second member which includes a body portion, wherein the body portion is bonded to the transition portion of the first member. The ceramic discharge chamber can be formed by injection molding a ceramic material to form the first member, the first member forming a first portion of the ceramic discharge chamber; and bonding the first member to a second member which forms a second portion of the ceramic discharge chamber. The members which form the ceramic discharge chamber can greatly facilitate assembly of the discharge chamber, because the discharge chamber can be constructed with only one or two bonds between the members.
    Type: Grant
    Filed: April 7, 2003
    Date of Patent: September 14, 2004
    Assignee: General Electric Company
    Inventors: Venkat Subramaniam Venkataramani, Charles David Greskovich, Curtis Edward Scott, James Anthony Brewer
  • Patent number: 6768326
    Abstract: A radiation detector includes: a scintillator which produces UV photons in response to receiving radiation from a radiation producing source; and, a wide bandgap semiconductor device sensitive to the UV photons produced by the scintillator. The semiconductor device produces an electric signal as a function of the amount of UV photons incident thereon. Preferably, the electric signal is then measure, recorded and/or otherwise analyzed.
    Type: Grant
    Filed: October 1, 2001
    Date of Patent: July 27, 2004
    Assignee: General Electric Company
    Inventors: Dale M. Brown, Donald T. McGrath, Charles David Greskovich, Robert Joseph Lyons
  • Publication number: 20030173902
    Abstract: A ceramic discharge chamber for a lamp, according to an exemplary embodiment of the invention, comprises a first member which includes a leg portion and a transition portion, wherein the leg portion and the transition portion are integrally formed as one piece from a ceramic material, and a second member which includes a body portion, wherein the body portion is bonded to the transition portion of the first member. The ceramic discharge chamber can be formed by injection molding a ceramic material to form the first member, the first member forming a first portion of the ceramic discharge chamber; and bonding the first member to a second member which forms a second portion of the ceramic discharge chamber. The members which form the ceramic discharge chamber can greatly facilitate assembly of the discharge chamber, because the discharge chamber can be constructed with only one or two bonds between the members.
    Type: Application
    Filed: April 7, 2003
    Publication date: September 18, 2003
    Inventors: Venkat Subramaniam Venkataramani, Charles David Greskovich, Curtis Edward Scott, James Anthony Brewer
  • Publication number: 20030127630
    Abstract: The present invention provides terbium or lutetium garnet x ray scintillators activated with a rare earth metal ion, such as cerium, and treated by annealing in a controlled atmosphere comprising a predetermined amount of oxygen for a predetermined time and temperature to reduce radiation damage that would otherwise occur when the scintillator material is exposed to high energy radiation, such as the type of radiation required to use the scintillator for medical radiographic imaging and the like. In an embodiment, a single crystal or a polycrystalline scintillator comprising the general formula (Tb1−xLuxCey)3Al5O12 (where 0<x≦0.5, and y is in the range from about 0.0005 to about 0.2, and annealed at 1400° C. to 1500° C. in a controlled atmosphere comprising 1×10−6 to 0.22 atm oxygen shows an increased resistance to radiation damage.
    Type: Application
    Filed: December 10, 2002
    Publication date: July 10, 2003
    Inventors: James Scott Vartuli, Steven Jude Duclos, Robert Joseph Lyons, Charles David Greskovich
  • Patent number: 6583563
    Abstract: A ceramic discharge chamber for a lamp, according to an exemplary embodiment of the invention, comprises a first member which includes a leg portion and a transition portion, wherein the leg portion and the transition portion are integrally formed as one piece from a ceramic material, and a second member which includes a body portion, wherein the body portion is bonded to the transition portion of the first member. The ceramic discharge chamber can be formed by injection molding a ceramic material to form the first member, the first member forming a first portion of the ceramic discharge chamber; and bonding the first member to a second member which forms a second portion of the ceramic discharge chamber. The members which form the ceramic discharge chamber can greatly facilitate assembly of the discharge chamber, because the discharge chamber can be constructed with only one or two bonds between the members.
    Type: Grant
    Filed: February 16, 1999
    Date of Patent: June 24, 2003
    Assignee: General Electric Company
    Inventors: Venkat Subramaniam Venkataramani, Charles David Greskovich, Curtis Edward Scott, James Anthony Brewer, Changlong Ning
  • Publication number: 20030052701
    Abstract: A radiation detector includes: a scintillator which produces UV photons in response to receiving radiation from a radiation producing source; and, a wide bandgap semiconductor device sensitive to the UV photons produced by the scintillator. The semiconductor device produces an electric signal as a function of the amount of UV photons incident thereon. Preferably, the electric signal is then measure, recorded and/or otherwise analyzed.
    Type: Application
    Filed: October 1, 2001
    Publication date: March 20, 2003
    Inventors: Dale M. Brown, Donald T. McGrath, Charles David Greskovich, Robert Joseph Lyons
  • Patent number: 6496250
    Abstract: A method of preparing and testing an array of ceramics for optical properties, comprising: providing a host material that is capable of being made optically transparent or translucent upon sintering; forming the host material into an array of pixels attached to a base plate; doping the host material; reacting the host material and the dopant, to form an array of products; and testing the products for optical properties.
    Type: Grant
    Filed: September 29, 2000
    Date of Patent: December 17, 2002
    Assignee: General Electric Company
    Inventors: Steven Jude Duclos, Charles David Greskovich
  • Patent number: 6475942
    Abstract: A process for converting a polycrystalline ceramic material to a single crystal material includes the steps of doping at least a first portion of the polycrystalline ceramic material with a conversion-enhancing dopant having a +6 valence state in the unfired ceramic material and heating the polycrystalline ceramic material to convert at least a second portion of the polycrystalline ceramic material to a single crystal ceramic material. Preferably, the ceramic material is alumina and the conversion-enhancing dopant is molybdenum or tungsten.
    Type: Grant
    Filed: September 5, 2000
    Date of Patent: November 5, 2002
    Assignee: General Electric Company
    Inventors: James Anthony Brewer, Charles David Greskovich, Curtis Edward Scott
  • Patent number: 6402987
    Abstract: A Y(P,V)O4:Eu3+ red emitting phosphor is doped with at least one of a trivalent rare earth ion excluding Eu and a divalent metal ion to improve the lumen maintenance of the phosphor. The preferred material is the Y(P,V)O4:Eu3+ phosphor doped with trivalent Tb3+ ions and divalent Mg2+ ions.
    Type: Grant
    Filed: December 1, 1999
    Date of Patent: June 11, 2002
    Assignee: General Electric Company
    Inventors: Alok Mani Srivastava, Charles David Greskovich, Steven Jude Duclos, Holly Ann Comanzo, William Winder Beers
  • Patent number: 6361735
    Abstract: The invention relates to a method of forming a composite article comprising the steps of forming a plurality of green ceramic elements, wherein the green ceramic elements are arranged side by side, and the green ceramic elements are spaced from each other by gaps; filling the gaps with a second material; and sintering the green ceramic elements with the second material to form the composite article. The second material, after being sintered, acts as a reflector layer to prevent substantially all light in one of the sintered ceramic elements from reaching an adjacent sintered ceramic element. The step of filling the gaps may be carried out by forming a slurry containing the second material in powder form and immersing the green ceramic elements in the slurry. The process of cosintering the green ceramic elements with the reflector composition provides improved dimensional control during sintering and reduces processing costs.
    Type: Grant
    Filed: September 1, 1999
    Date of Patent: March 26, 2002
    Assignee: General Electric Company
    Inventors: Venkat Subramaniam Venkataramani, Charles David Greskovich, Steven Jude Duclos, James Anthony Brewer
  • Patent number: 6093347
    Abstract: Decay time in scintillator compositions comprising yttrium or lutetium and gadolinium oxides and europium oxide is decreased by incorporating therein at least one of the oxides of ytterbium, samarium, praseodymium, neodymium, dysprosium, holmium, thulium, cerium and erbium as an acceptor. Other properties including afterglow and radiation damage are maintained at acceptable levels.
    Type: Grant
    Filed: October 28, 1998
    Date of Patent: July 25, 2000
    Assignee: General Electric Company
    Inventors: Michael John Lynch, Steven Jude Duclos, Charles David Greskovich, Alok Mani Srivastava
  • Patent number: 5882547
    Abstract: Decay time in scintillator compositions comprising yttrium or lutetium and gadolinium oxides and europium oxide is decreased by incorporating therein at least one of the oxides of ytterbium, samarium, praseodymium, neodymium, dysprosium, holmium, thulium, cerium and erbium as an acceptor. Other properties including afterglow and radiation damage are maintained at acceptable levels.
    Type: Grant
    Filed: May 19, 1997
    Date of Patent: March 16, 1999
    Assignee: General Electric Company
    Inventors: Michael John Lynch, Steven Jude Duclos, Charles David Greskovich, Alok Mani Srivastava