Patents by Inventor Thomas B. Cho

Thomas B. Cho 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).

  • Publication number: 20020121925
    Abstract: A multistage analog circuit for independently controlling a bias current in each stage of the multistage analog circuit having an input stage, an intermediate stage, and an output stage, includes a first current source which controls the input stage of the circuit, a second current source which controls the intermediate stage of the circuit, and a third current source which controls the output stage of the circuit. The bias current in each stage of the circuit is set by the first, second, and third current sources. An output voltage of the circuit is capable of remaining the same when the first current source is changed to affect an input transconductance of the circuit.
    Type: Application
    Filed: April 27, 2000
    Publication date: September 5, 2002
    Inventors: Christopher D. Nilson, Thomas B. Cho
  • Patent number: 5077185
    Abstract: An element comprising a support having an antistatic layer applied to one side thereof and wherein said antistatic layer also contains antihalation dyes absorbing light at 440 nm and below and with matte particles therein, is described. A photosensitive layer, e.g., photographic silver halide layer can be coated on the opposite side of the support. The element exhibits excellent antistatic and antihalation properties as well as low dye stain and improved dimensional stability, compared to elements wherein the antihalation dyes are coated in a separate layer. These products are especially useful as so-called "bright-light films" that are designed for contact printing and the like.
    Type: Grant
    Filed: March 28, 1991
    Date of Patent: December 31, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Thomas B. Cho, Ray B. Myers
  • Patent number: 4960687
    Abstract: An improved process for the preparation of backing layers with improved coating qualities is described. These layers are designed to transmit antistatic properties from antistatic layers coated under the backing layers and provide antihalation or anticurl effects in addition thereto. The process of this invention includes in-line addition of a pre-stabilized crosslinking solution to a gelatino-conductive polymer solution just prior to the coating thereof. Smooth, skip-free coatings are obtained and the solutions are stable and can be maintained for long periods of time.
    Type: Grant
    Filed: September 29, 1989
    Date of Patent: October 2, 1990
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Thomas B. Cho
  • Patent number: 4891308
    Abstract: As part of a photographic film, a backing antistatic layer is coated at a pH of 3 to 12 with an auxiliary layer consisting essentially of at least one crosslinkable conductive polymer and a crosslinking agent for the conductive polymer dispersed in a binder, e.g., gelatin, to conduct the antistatic properties from the antistatic underlayer to the surface of the backing layer. The crosslinkable conductive polymer and crosslinking agent can be present in separate layers on the backing layer. The film is useful in the areas of graphic arts, printing, medical and information systems.
    Type: Grant
    Filed: April 14, 1989
    Date of Patent: January 2, 1990
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Thomas B. Cho
  • Patent number: 4585730
    Abstract: As part of a photographic film, a backing layer is coated with an auxiliary layer designed to conduct antistatic properties from an antistatic underlayer to the surface of the backing.
    Type: Grant
    Filed: January 16, 1985
    Date of Patent: April 29, 1986
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Thomas B. Cho