Patents by Inventor Ippei Ogawa

Ippei Ogawa 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).

  • Phase-change information recording medium and optical recording method to make higher rotation rates feasible
    Patent number: 6280810
    Abstract: An information recording medium includes a substrate, a first protective layer formed on the substrate, a recording layer formed on the first protective layer, and a second protective layer formed on the recording layer. The first protective layer has a thickness in a range from 65 nm to 130 nm. The second protective layer has a thickness in a range from 15 nm to 45 nm. The recording layer has a thickness in a range from 15 nm to 35 nm and is composed of a phase-change alloy with the composition in terms of atomic percentage being represented by the formula AgaInbSbcTed where 0<a<6, 3≦b≦15, 50≦c≦65, 20≦d≦35, a+b+c+d=100. The information recording medium is configured to provide capabilities of reading, writing and overwriting of information at linear rotation rates ranging from 1.2 m/s to 11.2 m/s.
    Type: Grant
    Filed: October 27, 1999
    Date of Patent: August 28, 2001
    Assignee: Ricoh Company, Ltd.
    Inventors: Yuki Nakamura, Katsuyuki Yamada, Eiji Noda, Ippei Ogawa