Patents by Inventor Fumiaki Tsukuda

Fumiaki Tsukuda 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).

  • Patent number: 5715313
    Abstract: Information is recorded on a floppy disk in a state in which the confidentiality of the information is maintained. An ID signal representing ID information is magnetically recorded down to the lower layer of a floppy disk when data is recorded. A data signal representing information (a data file) to be recorded is also magnetically recorded down to the lower layer of the floppy disk. A security signal is magnetically recorded on the upper layer of the floppy disk over at least the data signal that has been recorded on the lower layer of the floppy disk. At the time of data reproduction, the ID signal is reproduced from the floppy disk and the ID information represented by the reproduced ID signal is compared with entered ID information. When the two items of compared ID information agree, the security signal that has been recorded on the upper layer of the floppy disk is erased. The data signal that has been recorded on the lower layer of the floppy disk is then reproduced.
    Type: Grant
    Filed: September 28, 1995
    Date of Patent: February 3, 1998
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Fumiaki Tsukuda, Tsutomu Sugisaki, Yasushi Endo
  • Patent number: 4601946
    Abstract: A magnetic recording medium is disclosed which comprises a non-magnetic support having provided thereon a magnetic recording layer consisting ferromagnetic powder and containing graphite and a fatty acid ester.
    Type: Grant
    Filed: July 26, 1984
    Date of Patent: July 22, 1986
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Shinobu Iida, Nobutaka Yamaguchi, Fumiaki Tsukuda, Masaaki Fujiyama, Eiichi Tadokoro