Patents by Inventor Shinichi Ikenaga

Shinichi Ikenaga 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: 5579256
    Abstract: Herein disclosed is a semiconductor memory device, in which peripheral circuits are arranged in a cross area of a semiconductor chip composed of the longitudinal center portions and the transverse center portions, and in which memory arrays are arranged in the four regions which are divided by the cross area. Thanks to this structure in which the peripheral circuits are arranged at the center portion of the chip, the longest signal transmission paths can be shortened to about one half of the chip size to speed up the DRAM which is intended to have a large storage capacity.
    Type: Grant
    Filed: May 31, 1995
    Date of Patent: November 26, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Kazuhiko Kajigaya, Kazuyuki Miyazawa, Manabu Tsunozaki, Kazuyoshi Oshima, Takashi Yamazaki, Yuji Sakai, Jiro Sawada, Yasunori Yamaguchi, Tetsurou Matsumoto, Shinji Udo, Hiroshi Yoshioka, Hirokazu Saito, Mitsuhiro Takano, Makoto Morino, Sinichi Miyatake, Eiji Miyamoto, Yasuhiro Kasama, Akira Endo, Ryoichi Hori, Jun Etoh, Masashi Horiguchi, Shinichi Ikenaga, Atsushi Kumata
  • Patent number: 4949306
    Abstract: A highly integrated memory features increased reading speed and writing speed. A sense circuit for this memory including a memory cell array having a plurality of memory cells each of which including at least one insulated gate field effect transistor, and a plurality of data lines to which the memory cells are connected. The memory also includes an address selection mechanism which is capable of selecting a memory cell out of a plurality of memory cells and connecting it to the data line. A sense amplifier a mechanism which is connected to the data line and amplifies a voltage according to the data of a memory cell. A common line (input/output line) is connected to the data lines, via a column switch, where the selection depends upon a column address. A main amplifier is connected to the common line (input/output line), and has at least a mechanism for stabilizing the voltage of the common line (input/output line) and an amplifying mechanism.
    Type: Grant
    Filed: June 1, 1988
    Date of Patent: August 14, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Yoshinobu Nakagome, Masakazu Aoki, Masashi Horiguchi, Kiyoo Itoh, Shinichi Ikenaga
  • Patent number: 4942556
    Abstract: In a defect relieving technology which replaces defective memory cells of a semiconductor memory device by spare memory cells, use is made of an associative memory. Address information of a defective memory cell is stored as a reference data of the associative memory, and new address information of a spare memory cell is written down as output data of the associative memory. A variety of improvements are made to the associative memory. For instance, a plurality of coincidence detection signal lines of the associative memory are divided into at least two groups, and one group among them is selected by switching means. Reference data of the associative memory comprises three values consisting of binary information of "0" and "1", and don't care value "X". The associative memory further includes a plurality of electrically programable non-volatile semiconductor memory elements.
    Type: Grant
    Filed: July 10, 1989
    Date of Patent: July 17, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Toshio Sasaki, Masakazu Aoki, Masashi Horiguchi, Yoshinobu Nakagome, Shinichi Ikenaga, Toshiaki Masuhara
  • Patent number: 4726021
    Abstract: A semiconductor memory having an error correcting function is provided, which has a device by which the user finds no difficulty in making use of the semiconductor memory and can test it with ease. In the semiconductor memory, a signal indicative of the completion of the preparation for reading/writing is outputted from the memory so that the user, after detecting the output of this signal, performs reading/writing data. To facilitate tests, such as a memory cell test for a redundant bit (check bit), an encoding circuit test and a decoding circuit test, the present invention provides that the arranged tests can be made independently of each other.
    Type: Grant
    Filed: April 17, 1986
    Date of Patent: February 16, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Masashi Horiguchi, Masakazu Aoki, Yoshinobu Nakagome, Shinichi Ikenaga, Katsuhiro Shimohigashi
  • Patent number: 4709350
    Abstract: In a semiconductor memory for reading and writing of stored charge in an X-Y address system by arranging a plurality of memory cells each including a capacitance element and one MOS-FET in matrix, this invention discloses a semiconductor memory using multiple level storage structure for read and write of at least more than two multi-level data stored in the capacitance elements, by applying a multi-level step voltage to the plate electrode of the capacitance or to the gate electrode of MOS-FET so as to write and read signal charge.
    Type: Grant
    Filed: July 5, 1984
    Date of Patent: November 24, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Yoshinobu Nakagome, Masakazu Aoki, Masashi Horiguchi, Katsuhiro Shimohigashi, Shinichi Ikenaga
  • Patent number: 4701884
    Abstract: A semiconductor memory device is proposed wherein at least an array comprising a plurality of memory cells each having at least one capacity, a select mechanism for specifying the position of each memory cell, data lines connected to said memory cells for transmitting the data and a data writing and a data reading mechanisms are provided.
    Type: Grant
    Filed: August 14, 1986
    Date of Patent: October 20, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Masakazu Aoki, Masashi Horiguchi, Yoshinobu Nakagome, Shinichi Ikenaga, Katsuhiro Shimohigashi, Toshiaki Masuhara, Kiyoo Itoh, Hideo Nakamura, Osamu Minato
  • Patent number: 4661929
    Abstract: In a semiconductor memory includes a memory array consisting of a plurality of memory cells respectively having at least one storage capacitor, an addressing circuit which designates location of each memory cell, data lines which transmit data connected to said memory cells and data writing and reading circuits connected to said data lines. The semiconductor memory has a multiple level storage structure. In particular, the memory includes an arrangement for sequentially applying, on a time series basis, different voltages of at least 3 levels or more to the gate of a switching MOS transistor of said memory cells, a bias charge supplying means as said data reading circuit and a column register providing at least two or more storage cells which temporarily store said data.
    Type: Grant
    Filed: December 24, 1984
    Date of Patent: April 28, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Masakazu Aoki, Yoshinobu Nakagome, Masashi Horiguchi, Shinichi Ikenaga, Katsuhiro Shimohigashi
  • Patent number: 4636985
    Abstract: In a semiconductor memory in which a large number of memory cells are arrayed in the shape of a matrix, arrangements are provided for a high-sensitivity read-out. In one embodiment, a writing circuit, a voltage amplifier and a sense amplifier are successively connected to a data line that connects input and output ends of the memory cells in an identical row, with the voltage amplifier being formed as a CTD voltage amplifier that is composed of two charge transfer gates and a driving gate located between them. In accordance with another embodiment, a charge supplying circuit and a charge transfer circuit can be coupled between the memory cells and the sense amplifier to allow information transfer without any substantial loss.
    Type: Grant
    Filed: September 7, 1984
    Date of Patent: January 13, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Masakazu Aoki, Yoshinobu Nakagome, Masahi Horiguchi, Toshifumi Ozaki, Katsuhiro Shimohigashi, Shinichi Ikenaga