Patents by Inventor Takchiko Kumagai

Takchiko Kumagai 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).

  • Light-guide plate, surface light emitting device using light-guide plate and method of manufacturing light-guide plate
    Patent number: 7099554
    Abstract: At the time of forming irregularities on at least one of a reflection face and an emitting face of a light-guide plate, irregularities are formed as a plurality of linear grooves formed in a direction perpendicular to the entrance face. When the grooves are formed by means of grinding, surfaces of the grooves are made rough. Therefore, light can be appropriately condensed and diffused by the grooves, and the luminance can be enhanced and the unevenness of the luminance can be reduced.
    Type: Grant
    Filed: March 3, 2005
    Date of Patent: August 29, 2006
    Assignee: Nidec Copal Corporation
    Inventor: Takchiko Kumagai
  • Light-guide plate, surface light emitting device using light-guide plate and method of manufacturing light-guide plate
    Publication number: 20050196123
    Abstract: At the time of forming irregularities on at least one of a reflection face and an emitting face of a light-guide plate, irregularities are formed as a plurality of linear grooves formed in a direction perpendicular to the entrance face. When the grooves are formed by means of grinding, surfaces of the grooves are made rough. Therefore, light can be appropriately condensed and diffused by the grooves, and the luminance can be enhanced and the unevenness of the luminance can be reduced.
    Type: Application
    Filed: March 3, 2005
    Publication date: September 8, 2005
    Applicant: Nidec Copal Corporation
    Inventor: Takchiko Kumagai