Patents by Inventor Koujiro Tanaka

Koujiro Tanaka 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).

  • Optical disk master, optical disk substrate stamper, process for production thereof, and magneto-optical recording medium
    Patent number: 7101656
    Abstract: A process for producing an optical disk master, comprises the steps of forming a photoresist layer on a glass master, cutting the photoresist layer by projecting light beam onto the glass master having the photoresist layer thereon to expose the photoresist layer to light, developing the photoresist layer after the cutting step to form a hollow portion corresponding to the light-exposed portion, and carrying out an ion treatment by projecting ions onto the developed photoresist layer to decrease the thickness of the photoresist layer at the developed hollow portion to reach the prescribed depth by the ion-treatment.
    Type: Grant
    Filed: March 28, 2002
    Date of Patent: September 5, 2006
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masahito Konishi, Keiji Nishikiori, Koujiro Tanaka
  • Optical disk master, optical disk substrate stamper, process for production thereof, and magneto-optical recording medium
    Publication number: 20020182546
    Abstract: A process for producing an optical disk master, comprises the steps of forming a photoresist layer on a glass master, cutting the photoresist layer by projecting light beam onto the glass master having the photoresist layer thereon to expose the photoresist layer to light, developing the photoresist layer after the cutting step to form a hollow portion corresponding to the light-exposed portion, and carrying out an ion treatment by projecting ions onto the developed photoresist layer to decrease the thickness of the photoresist layer at the developed hollow portion to reach the prescribed depth by the ion-treatment.
    Type: Application
    Filed: March 28, 2002
    Publication date: December 5, 2002
    Inventors: Masahito Konishi, Keiji Nishikiori, Koujiro Tanaka