Patents by Inventor Nobutaka Kumada

Nobutaka Kumada 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).

  • ND filter and aperture device including the same
    Patent number: 6842301
    Abstract: An ND filter includes a substrate formed in a plastic sheet and a deposit film deposited on a surface of the substrate. The plastic sheet is composed of a norbornene resin and the deposit film is composed of a nickel-chromium alloy. The norbornene resin has a small thermal shrinkage factor and prevents the plastic sheet from wrinkling. The nickel-chromium alloy has a good oxidation resistance and ensures a uniform light transmittance of the deposit film over the entire visible light region.
    Type: Grant
    Filed: June 23, 2003
    Date of Patent: January 11, 2005
    Assignee: Nisca Corporation
    Inventors: Katsura Nakajima, Kazuhiro Fukasawa, Nobutaka Kumada
  • ND filter, method for producing the ND filter, and aperture device including the ND filter
    Patent number: 6842302
    Abstract: An ND filter includes a substrate formed in a plastic sheet and a deposited film formed on a surface of the substrate. The plastic sheet has at least 120° C. of a glass transition temperature. In producing the ND filter, the deposited film is formed on the surface of the substrate at a temperature below the glass transition temperature of the plastic sheet to suppress deformation due to expansion and contraction and to prevent the plastic sheet from wrinkling.
    Type: Grant
    Filed: June 23, 2003
    Date of Patent: January 11, 2005
    Assignee: Nisca Corporation
    Inventors: Katsura Nakajima, Kazuhiro Fukasawa, Nobutaka Kumada
  • ND filter and aperture device including the same
    Publication number: 20040027706
    Abstract: An ND filter includes a substrate formed in a plastic sheet and a deposit film deposited on a surface of the substrate. The plastic sheet is composed of a norbornene resin and the deposit film is composed of a nickel-chromium alloy. The norbornene resin has a small thermal shrinkage factor and prevents the plastic sheet from wrinkling. The nickel-chromium alloy has a good oxidation resistance and ensures a uniform light transmittance of the deposit film over the entire visible light region.
    Type: Application
    Filed: June 23, 2003
    Publication date: February 12, 2004
    Inventors: Katsura Nakajima, Kazuhiro Fukasawa, Nobutaka Kumada
  • ND filter, method for producing the ND filter, and aperture device including the ND filter
    Publication number: 20040008439
    Abstract: An ND filter includes a substrate formed in a plastic sheet and a deposited film formed on a surface of the substrate. The plastic sheet has at least 120° C. of a glass transition temperature. In producing the ND filter, the deposited film is formed on the surface of the substrate at a temperature below the glass transition temperature of the plastic sheet to suppress deformation due to expansion and contraction and to prevent the plastic sheet from wrinkling.
    Type: Application
    Filed: June 23, 2003
    Publication date: January 15, 2004
    Inventors: Katsura Nakajima, Kazuhiro Fukasawa, Nobutaka Kumada