Patents by Inventor Nobuo Ikuta

Nobuo Ikuta 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: 5781627
    Abstract: A semiconductor integrated circuit device with a copy-preventive function comprises a memory for storing data to be used by users, an input unit for performing various logical operations on at least one input information fed externally and accessing the memory, an output unit for performing various logical operations on the data at the time of supplying the data from the memory, a judging unit for comparing at least one of the state of the input information, the logical state of the input unit, the logical state of the output unit, and the state of data provided by the output unit with specific judgment information and indicating the result of comparison, and a control unit that when the result indicated by the judging unit reveals that the at least one of the states is consistent with a specific state, acts at least on the output unit so as to prevent data stored in the memory from being supplied normally.
    Type: Grant
    Filed: July 31, 1995
    Date of Patent: July 14, 1998
    Assignee: Fujitsu Limited
    Inventors: Nobuo Ikuta, Kouji Ueno, Kouji Shishido, Yutaka Fukutani, Youji Arayama, Tomohiro Nakayama, Takanori Shiga, Masakazu Kimura, Hiroyuki Fujimoto, Yoshiyuki Fujita
  • Patent number: 4809227
    Abstract: A read only memory device including: a memory cell array having a plurality of memory cells each storing one of three states; selection means, connected to the memory cell array, for selecting a pair of the memory cells from the memory cell array simultaneously in accordance with an address signal; a first sense amplifier, operatively connected to one of the pair of the memory cells, for producing a three bit output corresponding to the state stored in the one of the pair of the memory cells selected by the selection means; and a second sense amplifier, operatively connected another of the pair of memory cells, for producing a three bit output corresponding to the state stored in the another of the pair of the memory cells selected by the selection means.
    Type: Grant
    Filed: August 5, 1987
    Date of Patent: February 28, 1989
    Assignee: Fujitsu Limited
    Inventors: Yasuo Suzuki, Yasuaki Suzuki, Nobuo Ikuta