Patents by Inventor Shigeto Oiri

Shigeto Oiri 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).

  • Magnetic recording medium having a magnetic layer and a coating thereunder
    Publication number: 20010051286
    Abstract: A magnetic recording medium comprising a nonmagnetic substrate, a liquid lubricant-containing coating layer having a porosity (U) formed on the substrate, and a magnetic layer having a porosity (M) formed directly on the coating layer. The ratio of porosity (U/M) between the coating and magnetic layers is between 0.75 and 1.25. The volume percentage of the lubricant contained in the pores of the coating layer based on the whole pore volume in the coating layer is from 35 to 85%. This improves the durability of the magnetic layer.
    Type: Application
    Filed: June 20, 2001
    Publication date: December 13, 2001
    Inventors: Shigeto Oiri, Yoji Tsukamoto, Hideaki Yasui
  • Magnetic recording medium having a magnetic layer and a coating thereunder
    Patent number: 6274227
    Abstract: A magnetic recording medium comprising a nonmagnetic substrate, a liquid lubricant-containing coating layer having a porosity (U) formed on the substrate, and a magnetic layer having a porosity (M) formed directly on the coating layer. The ratio of porosity (U/M) between the coating and magnetic layers is between 0.75 and 1.25. The volume percentage of the lubricant contained in the pores of the coating layer based on the whole pore volume in the coating layer is from 35 to 85%. This improves the durability of the magnetic layer.
    Type: Grant
    Filed: September 24, 1999
    Date of Patent: August 14, 2001
    Assignee: Imation Corp.
    Inventors: Shigeto Oiri, Yoji Tsukamoto, Hideaki Yasui
  • Magnetic recording medium having a magnetic layer and a partially-filled liquid lubricant-containing coating thereunder
    Patent number: 5840410
    Abstract: A magnetic recording medium comprising a nonmagnetic substrate, a liquid lubricant-containing coating layer having a porosity (U) formed on the substrate, and a magnetic layer having a porosity (M) formed directly on the coating layer. The ratio of porosity (U/M) between the coating and magnetic layers is between 0.75 and 1.25. The volume percentage of the lubricant contained in the pores of the coating layer based on the whole pore volume in the coating layer is from 35 to 85%. This improves the durability of the magnetic layer.
    Type: Grant
    Filed: February 7, 1996
    Date of Patent: November 24, 1998
    Assignee: Imation Corp.
    Inventors: Shigeto Oiri, Yoji Tsukamoto, Hideaki Yasui
  • High recording density magnetic recording medium having an undercoat layer of iron oxide and carbon black
    Patent number: 5612122
    Abstract: A high recording density magnetic recording medium including a non-magnetic base film, a magnetic layer, and an undercoat layer provided therebetween. The undercoat layer includes non-magnetic particles, a binder resin, and a lubricant. The non-magnetic particles comprise (1) a non-magnetic iron oxide with an acicular ratio ranging from 5 to 10 and a long axis length ranging from 0.05 to 0.3 .mu.m, and (2) a carbon black having a structure constitution, and the weight ratio between said non-magnetic iron oxide and said carbon black is within the range between 85/15 and 99/1.
    Type: Grant
    Filed: August 8, 1995
    Date of Patent: March 18, 1997
    Assignee: Imation Corp.
    Inventors: Yoji Tsukamoto, Shigeto Oiri, Toshio Ohta