Patents by Inventor Lap-Tak Andrew Cheng

Lap-Tak Andrew Cheng 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: 8070906
    Abstract: This invention provides a process for improving the field emission of an electron field emitter comprised of an acicular emitting substance such as acicular carbon, an acicular semiconductor, an acicular metal or a mixture thereof, comprising applying a force to the surface of the electron field emitter wherein the force results in the removal of a portion of the electron field emitter thereby forming a new surface of the electron field emitter.
    Type: Grant
    Filed: July 16, 2008
    Date of Patent: December 6, 2011
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Robert Joseph Bouchard, Lap-Tak Andrew Cheng, David Herbert Roach, John Gerard Lavin
  • Patent number: 8011990
    Abstract: This invention provides a process for improving the field emission of an electron field emitter comprised of an acicular emitting substance such as acicular carbon, an acicular semiconductor, an acicular metal or a mixture thereof, comprising applying a force to the surface of the electron field emitter wherein the force results in the removal of a portion of the electron field emitter thereby forming a new surface of the electron field emitter.
    Type: Grant
    Filed: September 29, 2005
    Date of Patent: September 6, 2011
    Assignee: E.I. du Pont de Nemours and Company
    Inventors: Robert Joseph Bouchard, Lap-Tak Andrew Cheng, David Herbert Roach
  • Patent number: 8002603
    Abstract: Described herein are methods of manufacturing an electrode and emitter in a field emission device, and devices formed from the methods. Compositions useful for the manufacture of an electrode and emitter in a field emission device are also described.
    Type: Grant
    Filed: May 19, 2009
    Date of Patent: August 23, 2011
    Assignee: E.I. du Pont de Nemours and Company
    Inventors: Haixin Yang, Lap-Tak Andrew Cheng, Terry Roland Suess, Chien Lung Weng
  • Publication number: 20110006271
    Abstract: This invention provides a dielectric composition comprising a dielectric which is fireable in air at a temperature in the range of about 450° C. to about 550° C. and a conductive oxide selected from the group consisting of antimony-doped tin oxide, tin-doped indium oxide, a transition metal oxide which has mixed valence states or will form mixed valence states after firing in a nitrogen atmosphere at a temperature in the range of about 450° C. to about 550° C. and normally conducting precious metal oxides such as ruthenium dioxide, wherein the amount of conductive oxide present is from about 0.25 wt % to about 25 wt % of the total weight of dielectric and conductive oxide. This dielectric composition has reduced electrical resistance and is useful in electron field emission devices to eliminate charging of the dielectric in the vicinity of the electron emitter and the effect of static charge induced field emission.
    Type: Application
    Filed: July 14, 2010
    Publication date: January 13, 2011
    Applicant: E.I DU PONT DE NEMOURS AND COMPANY
    Inventors: Robert Joseph Bouchard, Lap-Tak Andrew Cheng, David Herbert Roach, Kenneth Warren Hang
  • Publication number: 20100264805
    Abstract: Under-gate field emission triode devices, and cathode assemblies for use therein, contain a charge dissipation layer. The charge dissipation layer may be located under or over the cathode electrode and/or electron field emitter.
    Type: Application
    Filed: October 3, 2008
    Publication date: October 21, 2010
    Applicant: E.I. DU PONT DE NEMOURS AND COMPANY
    Inventors: Adam Fennimore, Lap-Tak Andrew Cheng
  • Publication number: 20100252804
    Abstract: A field emission cathode assembly that has a UV-blocking, insulating dielectric layer (3.4).
    Type: Application
    Filed: November 26, 2008
    Publication date: October 7, 2010
    Applicant: E.I DU PONT DE NEMOURS AND COMPANY
    Inventors: Lap-Tak Andrew Cheng, Adam Fennimore
  • Patent number: 7763189
    Abstract: This invention provides a dielectric composition comprising a dielectric which is fireable in air at a temperature in the range of about 450° C. to about 550° C. and a conductive oxide selected from the group consisting of antimony-doped tin oxide, tin-doped indium oxide, a transition metal oxide which has mixed valence states or will form mixed valence states after firing in a nitrogen atmosphere at a temperature in the range of about 450° C. to about 550° C. and normally conducting precious metal oxides such as ruthenium dioxide, wherein the amount of conductive oxide present is from about 0.25 wt % to about 25 wt % of the total weight of dielectric and conductive oxide. This dielectric composition has reduced electrical resistance and is useful in electron field emission devices to eliminate charging of the dielectric in the vicinity of the electron emitter and the effect of static charge induced field emission.
    Type: Grant
    Filed: May 14, 2002
    Date of Patent: July 27, 2010
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Robert Joseph Bouchard, Lap-Tak Andrew Cheng, David Herbert Roadh, Kenneth Warren Hang
  • Patent number: 7750544
    Abstract: This invention provides compositions of matter that contain an electron emitting substance and an expansion material. The expansion material may, for example, be an intercalation compound. When a film is formed from the composition, expansion of the expansion material typically causes rupturing or fracturing of the film. No further treatment of the surface of the film is typically required after expansion of the expansion material to obtain good emission properties. A surface formed from such a fractured film acts as an efficient electron field emitter and thus is useful in vacuum microelectronic devices.
    Type: Grant
    Filed: March 27, 2007
    Date of Patent: July 6, 2010
    Assignee: E.I. du Pont de Nemours and Company
    Inventors: Lap-Tak Andrew Cheng, David Herbert Roach
  • Publication number: 20100072879
    Abstract: A field emission device in which a protective material is employed in relation to the anode wherein the protective material is selected from one or more members of the group consisting of amorphous carbon, graphite, diamond-like carbon, fullerenes, carbon nanotubes, a (co)polymer and an organic coating compound.
    Type: Application
    Filed: February 22, 2008
    Publication date: March 25, 2010
    Applicant: E. I. DU PONT DE NEMOURS AND COMPANY
    Inventors: Adam Fennimore, David Herbert Roach, Lap-Tak Andrew Cheng
  • Publication number: 20100044233
    Abstract: This invention relates to the electrochemical deposition of carbon nanotubes (“CNTs”) on a substrate using an electrochemical cell. A dispersion of a complex of CNTs and an anionic polymer is neutralized and thereby caused to deposit on the anode plate of the cell.
    Type: Application
    Filed: August 22, 2008
    Publication date: February 25, 2010
    Inventors: MING ZHENG, Lap-Tak Andrew Cheng
  • Publication number: 20090314647
    Abstract: This invention relates to the electrochemical deposition of carbon nanotubes (“CNTs”) on a substrate using an electrochemical cell. A dispersion of a complex of CNTs and an anionic polymer is neutralized and thereby caused to deposit on the anode plate of the cell.
    Type: Application
    Filed: February 22, 2008
    Publication date: December 24, 2009
    Applicant: E.I. DU PONT DE NEMOURS AND COMPANY
    Inventors: Ming Zheng, Lap-Tak Andrew Cheng, David Herbert Roach, Walter Mahler
  • Publication number: 20090284122
    Abstract: Described herein are methods of manufacturing an electrode and emitter in a field emission device, and devices formed from the methods. Compositions useful for the manufacture of an electrode and emitter in a field emission device are also described.
    Type: Application
    Filed: May 19, 2009
    Publication date: November 19, 2009
    Applicant: E.I. DU PONT DE NEMOURS AND COMPANY
    Inventors: HAIXIN YANG, LAP-TAK ANDREW CHENG, TERRY ROLAND SUESS, CHIEN LUNG WENG
  • Patent number: 7449081
    Abstract: This invention provides a process for improving the field emission of an electron field emitter comprised of an acicular emitting substance such as acicular carbon, an acicular semiconductor, an acicular metal or a mixture thereof, comprising applying a force to the surface of the electron field emitter wherein the force results in the removal of a portion of the electron field emitter thereby forming a new surface of the electron field emitter.
    Type: Grant
    Filed: June 15, 2001
    Date of Patent: November 11, 2008
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Robert Joseph Bouchard, Lap-Tak Andrew Cheng, John Gerard Lavin, David Herbert Roach
  • Publication number: 20080166666
    Abstract: This invention provides compositions that can be used as positive imageable photoresists. These compositions include positive imageable photopolymer systems and particulate materials. These compositions can be used in thick film and other processes to make films and patterned structures that are useful in producing electronic devices.
    Type: Application
    Filed: March 5, 2008
    Publication date: July 10, 2008
    Inventors: David Herbert Roach, Young H. Kim, Lap-Tak Andrew Cheng
  • Patent number: 7358037
    Abstract: The present invention concerns a process for the fabrication of electrical and electronic devices. A polymer film is patterned on a substrate. A thick film paste is deposited over the patterned polymer. The thick film paste is dried under conditions which allow diffusion of the polymer into the thick film paste. This renders the diffused area insoluble in alkaline development solution.
    Type: Grant
    Filed: January 22, 2004
    Date of Patent: April 15, 2008
    Assignee: E.I. du Pont de Nemours and Company
    Inventor: Lap-Tak Andrew Cheng
  • Patent number: 7317277
    Abstract: This invention provides compositions of matter that contain an electron emitting substance and an expansion material. The expansion material may, for example, be an intercalation compound. When a film is formed from the composition, expansion of the expansion material typically causes rupturing or fracturing of the film. No further treatment of the surface of the film is typically required after expansion of the expansion material to obtain good emission properties. A surface formed from such a fractured film acts as an efficient electron field emitter and thus is useful in vacuum microelectronic devices.
    Type: Grant
    Filed: April 23, 2003
    Date of Patent: January 8, 2008
    Assignee: E.I. du Pont de Nemours and Company
    Inventors: Lap-Tak Andrew Cheng, David Herbert Roach
  • Patent number: 7276844
    Abstract: This invention provides a process for improving the field emission of an electron field emitter comprised of an acicular emitting substance such as acicular carbon, an acicular semiconductor, an acicular metal or a mixture thereof, comprising applying a force to the surface of the electron field emitter wherein the force results in the removal of a portion of the electron field emitter thereby forming a new surface of the electron field emitter.
    Type: Grant
    Filed: April 15, 2005
    Date of Patent: October 2, 2007
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Robert Joseph Bouchard, Lap-Tak Andrew Cheng, John Gerald Lavin, David Herbert Roach
  • Patent number: 6864039
    Abstract: A photosensitive printing element comprising a support; and a photopolymerizable layer comprising a photopolymerizable composition comprising at least one elastomeric binder, at least one monomer, an initiator having sensitivity to actinic radiation, and at least one photobleachable compound having sensitivity to actinic radiation; is described. Preferred photobleachable compounds are unsubstituted or substituted naphthylvinyl pyridines; unsubstituted or substituted styrylquinolines; diphenyl maleic anhydride; isomers of any of the foregoing; derivatives of any of the foregoing; and any combination of the foregoing. Such photosensitive printing elements are used to prepare flexographic printing plates and are useful in enhancing resolution and differentiating image areas from non-image areas in images produced therefrom by reducing the deleterious effect of scattered light.
    Type: Grant
    Filed: April 15, 2003
    Date of Patent: March 8, 2005
    Assignee: E.I. du Pont de Nemours and Company
    Inventors: Lap Kin Cheng, Lap-Tak Andrew Cheng
  • Publication number: 20040173818
    Abstract: The present invention concerns a process for the fabrication of electrical and electronic devices. A polymer film is patterned on a substrate. A thick film paste is deposited over the patterned polymer. The thick film paste is dried under conditions which allow diffusion of the polymer into the thick film paste. This renders the diffused area insoluble in alkaline development solution.
    Type: Application
    Filed: January 22, 2004
    Publication date: September 9, 2004
    Inventor: Lap-Tak Andrew Cheng
  • Publication number: 20040170925
    Abstract: This invention provides compositions that can be used as positive imageable photoresists. These compositions include positive imageable photopolymer systems and particulate materials. These compositions can be used in thick film and other processes to make films and patterned structures that are useful in producing electronic devices.
    Type: Application
    Filed: December 4, 2003
    Publication date: September 2, 2004
    Inventors: David Herbert Roach, Young H. Kim, Lap-Tak Andrew Cheng