Patents by Inventor Tsuneo Inaba

Tsuneo Inaba 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).

  • Publication number: 20050180204
    Abstract: A memory cell of a magnetic memory device has an MTJ element and one end of the memory cell is selectively electrically connected to a ground potential line. A first bit line is electrically connected to the other end of the memory cell. A sense amplifier amplifies a difference in potential between the first bit line and a second bit line complementary to the first bit line so that the difference is equal to or larger than a difference between an internal power potential and a ground potential. A connection circuit disconnects the MTJ element from an electric connection between the ground potential line and the sense amplifier.
    Type: Application
    Filed: May 28, 2004
    Publication date: August 18, 2005
    Inventors: Ryousuke Takizawa, Kenji Tsuchida, Yoshihisa Iwata, Tsuneo Inaba
  • Publication number: 20050146926
    Abstract: A magnetic memory device includes first to n-th MTJ devices recording data and first to n-th transistors connected to the first to n-th MTJ devices, respectively. The word line generates a magnetic field to be applied to the first to n-th MTJ devices during a write operation. A read word line is connected to gates of the first to n-th transistors and applies a voltage for turning on the first to n-th transistors during a read operation. A first word line driver is connected to a first end or a second end of the write word line and drives the write word line. A second word line driver is connected to a first end of the read word line and drives the read word line. A second switching circuit selectively connects the second end of the read word line and the second end of the write word line.
    Type: Application
    Filed: March 3, 2005
    Publication date: July 7, 2005
    Inventor: Tsuneo Inaba
  • Patent number: 6914808
    Abstract: In an MRAM, a plurality of magnetic memory cells are arranges in rows and columns. Each of the plurality of magnetic memory cells is a magnetoresistive element having a tunnel magnetoresistive effect. Each of the plurality of magnetic memory cells includes two magnetoresistive elements that hold data items of opposite logic levels to each other and are connected in series.
    Type: Grant
    Filed: November 6, 2003
    Date of Patent: July 5, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Tsuneo Inaba
  • Patent number: 6906979
    Abstract: A plurality of cell arrays is provided with a plurality of word lines and bit line pairs. A plurality of sense amplifiers is connected so as to each of the plurality of bit line pairs. The plurality of sense amplifiers configures a memory core section together with the plurality of cell arrays. A pair of bit line kicker drive lines is arranged in the vicinity of the plurality of cell arrays, and a pair of bit line kickers is connected between the pair of bit line kicker drive lines and each of the plurality of bit line pairs. In the memory core section, a pair of drivers is arranged so as to correspond to each cell array, and each of the pair of drivers has an output node connected to the pair of bit line kicker drive lines. The pair of drivers drives the pair of bit line kicker drive lines so as to change a potential of one bit line of one of the plurality of bit line pairs via the pair of bit line kickers.
    Type: Grant
    Filed: October 17, 2002
    Date of Patent: June 14, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Tsuneo Inaba
  • Patent number: 6894923
    Abstract: A magnetic memory device includes first to n-th MTJ devices recording data and first to n-th transistors connected to the first to n-th MTJ devices, respectively. The word line generates a magnetic field to be applied to the first to n-th MTJ devices during a write operation. A read word line is connected to gates of the first to n-th transistors and applies a voltage for turning on the first to n-th transistors during a read operation. A first word line driver is connected to a first end or a second end of the write word line and drives the write word line. A second word line driver is connected to a first end of the read word line and drives the read word line. A second switching circuit selectively connects the second end of the read word line and the second end of the write word line.
    Type: Grant
    Filed: August 29, 2003
    Date of Patent: May 17, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Tsuneo Inaba
  • Publication number: 20040233711
    Abstract: A magnetic memory device includes first to n-th MTJ devices recording data and first to n-th transistors connected to the first to n-th MTJ devices, respectively. The word line generates a magnetic field to be applied to the first to n-th MTJ devices during a write operation. A read word line is connected to gates of the first to n-th transistors and applies a voltage for turning on the first to n-th transistors during a read operation. A first word line driver is connected to a first end or a second end of the write word line and drives the write word line. A second word line driver is connected to a first end of the read word line and drives the read word line. A second switching circuit selectively connects the second end of the read word line and the second end of the write word line.
    Type: Application
    Filed: August 29, 2003
    Publication date: November 25, 2004
    Inventor: Tsuneo Inaba
  • Publication number: 20040141368
    Abstract: In an MRAM, a plurality of magnetic memory cells are arranges in rows and columns. Each of the plurality of magnetic memory cells is a magnetoresistive element having a tunnel magnetoresistive effect. Each of the plurality of magnetic memory cells includes two magnetoresistive elements that hold data items of opposite logic levels to each other and are connected in series.
    Type: Application
    Filed: November 6, 2003
    Publication date: July 22, 2004
    Inventor: Tsuneo Inaba
  • Patent number: 6754122
    Abstract: After data readout, in equalizing a complementary pair of bit lines one of which has been overdriven with an overdrive voltage, excessive charges on the overdriven bit line are discharged by a discharge circuit. By adjusting the discharge period of the discharge circuit, the potential to which the bit lines are equalized is adjusted.
    Type: Grant
    Filed: February 5, 2003
    Date of Patent: June 22, 2004
    Assignees: Kabushiki Kaisha Toshiba, Fujitsu Limited
    Inventors: Masaharu Wada, Kenji Tsuchida, Tsuneo Inaba, Toshimi Ikeda
  • Patent number: 6731149
    Abstract: A first delay line for forward pulses and a second delay line for backward pulses are composed of unit delay elements. A state holding section determines the input position of a backward pulse on the second delay line according to the transfer position of a forward pulse transferred along the first delay line. In the unit delay elements constituting the first and second delay lines, the accuracy of synchronization can be improved by increasing the current driving capability of the transistors related to the rising of the pulse signal.
    Type: Grant
    Filed: December 6, 2001
    Date of Patent: May 4, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Katsuaki Isobe, Tsuneo Inaba, Hironobu Akita
  • Patent number: 6661734
    Abstract: A semiconductor memory device is disclosed, in which a first word drive line control circuit which supplies a word drive voltage corresponding to the decode output of the decoding circuit to the first word drive line, and has a first reset circuit which resets the first word drive line to a first potential when a first control signal is activated and a second reset circuit which resets the first word drive line to a second potential when a second control signal is activated, and a two-stage reset control circuit which controls changeover from the activated state of the first control signal to the activated state of the second control signal on the basis of the potential of the first word drive line to change the potential of the first word drive line in two stages.
    Type: Grant
    Filed: July 12, 2002
    Date of Patent: December 9, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsuneo Inaba, Kenji Tsuchida
  • Patent number: 6650590
    Abstract: One (first level shift circuit) of first and second level shift circuits is provided in a local word-drive-line driving circuit located near memory cell arrays. The second level shift circuit is provided in a global word-drive-line driving circuit located remote from the memory cell arrays.
    Type: Grant
    Filed: March 22, 2002
    Date of Patent: November 18, 2003
    Assignees: Kabushiki Kaisha Toshiba, Fujitsu Limited
    Inventors: Tsuneo Inaba, Fumihiro Kohno, Kenji Tsuchida, Toshimi Ikeda
  • Publication number: 20030174545
    Abstract: After data readout, in equalizing a complementary pair of bit lines one of which has been overdriven with an overdrive voltage, excessive charges on the overdriven bit line are discharged by a discharge circuit. By adjusting the discharge period of the discharge circuit, the potential to which the bit lines are equalized is adjusted.
    Type: Application
    Filed: February 5, 2003
    Publication date: September 18, 2003
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Masaharu Wada, Kenji Tsuchida, Tsuneo Inaba, Toshimi Ikeda
  • Publication number: 20030072201
    Abstract: A plurality of cell arrays is provided with a plurality of word lines and bit line pairs. A plurality of sense amplifiers is connected so as to each of the plurality of bit line pairs. The plurality of sense amplifiers configures a memory core section together with the plurality of cell arrays. A pair of bit line kicker drive lines is arranged in the vicinity of the plurality of cell arrays, and a pair of bit line kickers is connected between the pair of bit line kicker drive lines and each of the plurality of bit line pairs. In the memory core section, a pair of drivers is arranged so as to correspond to each cell array, and each of the pair of drivers has an output node connected to the pair of bit line kicker drive lines. The pair of drivers drives the pair of bit line kicker drive lines so as to change a potential of one bit line of one of the plurality of bit line pairs via the pair of bit line kickers.
    Type: Application
    Filed: October 17, 2002
    Publication date: April 17, 2003
    Applicant: Kabushiki Kaisha Toshiba
    Inventor: Tsuneo Inaba
  • Publication number: 20030012075
    Abstract: A semiconductor memory device is disclosed, in which a first word drive line control circuit which supplies a word drive voltage corresponding to the decode output of the decoding circuit to the first word drive line, and has a first reset circuit which resets the first word drive line to a first potential when a first control signal is activated and a second reset circuit which resets the first word drive line to a second potential when a second control signal is activated, and a two-stage reset control circuit which controls changeover from the activated state of the first control signal to the activated state of the second control signal on the basis of the potential of the first word drive line to change the potential of the first word drive line in two stages.
    Type: Application
    Filed: July 12, 2002
    Publication date: January 16, 2003
    Inventors: Tsuneo Inaba, Kenji Tsuchida
  • Publication number: 20020141277
    Abstract: One (first level shift circuit) of first and second level shift circuits is provided in a local word-drive-line driving circuit located near memory cell arrays. The second level shift circuit is provided in a global word-drive-line driving circuit located remote from the memory cell arrays.
    Type: Application
    Filed: March 22, 2002
    Publication date: October 3, 2002
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Tsuneo Inaba, Fumihiro Kohno, Kenji Tsuchida, Toshimi Ikeda
  • Patent number: 6452860
    Abstract: A semiconductor memory device has a segment type word line structure and comprises a plurality of main word lines and a plurality of sub word lines which are arranged at different levels. The semiconductor memory device is provided with a memory cell array divided into a plurality of cell array blocks. A plurality of sub row decoder areas, each for selecting one of the sub word lines, are defined between the cell array blocks. A plurality of first metal wiring lines formed by use of the same wiring layer as the main word lines are provided. The first metal wiring lines pass across the sub row decoder areas and the cell array blocks.
    Type: Grant
    Filed: June 4, 2001
    Date of Patent: September 17, 2002
    Assignees: Kabushiki Kaisha Toshiba, Fujitsu Limited
    Inventors: Masaharu Wada, Kenji Tsuchida, Tsuneo Inaba, Atsushi Takeuchi, Toshimi Ikeda, Kuninori Kawabata
  • Patent number: 6404698
    Abstract: There is provided a semiconductor memory device which comprises a plurality of memory cells, a plurality of bit lines connected with the plurality of memory cells, a plurality of word lines connected with the plurality of memory cells, a plurality of data line pairs, a plurality of transfer gates for effecting controlled connection of the plurality of bit lines with the plurality of data lines, a plurality of column select lines for controlling conductibility of the plurality of the transfer gates, and a column select line drive circuit for simultaneously selecting and driving at least two of the plurality of column select lines corresponding to one-time column address input from the outside of the chip.
    Type: Grant
    Filed: January 21, 2000
    Date of Patent: June 11, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsuneo Inaba, Shinichiro Shiratake, Kenji Tsuchida
  • Publication number: 20020036524
    Abstract: A first delay line for forward pulses and a second delay line for backward pulses are composed of unit delay elements. A state holding section determines the input position of a backward pulse on the second delay line according to the transfer position of a forward pulse transferred along the first delay line. In the unit delay elements constituting the first and second delay lines, the accuracy of synchronization can be improved by increasing the current driving capability of the transistors related to the rising of the pulse signal.
    Type: Application
    Filed: December 6, 2001
    Publication date: March 28, 2002
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Katsuaki Isobe, Tsuneo Inaba, Hironobu Akita
  • Patent number: 6359480
    Abstract: A first delay line for forward pulses and a second delay line for backward pulses are composed of unit delay elements. A state holding section determines the input position of a backward pulse on the second delay line according to the transfer position of a forward pulse transferred along the first delay line. In the unit delay elements constituting the first and second delay lines, the accuracy of synchronization can be improved by increasing the current driving capability of the transistors related to the rising of the pulse signal.
    Type: Grant
    Filed: February 16, 2000
    Date of Patent: March 19, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Katsuaki Isobe, Tsuneo Inaba, Hironobu Akita
  • Publication number: 20010048631
    Abstract: A semiconductor memory device has a segment type word line structure and comprises a plurality of main word lines and a plurality of sub word lines which are arranged at different levels. The semiconductor memory device is provided with a memory cell array divided into a plurality of cell array blocks. A plurality of sub row decoder areas, each for selecting one of the sub word lines, are defined between the cell array blocks. A plurality of first metal wiring lines formed by use of the same wiring layer as the main word lines are provided. The first metal wiring lines pass across the sub row decoder areas and the cell array blocks.
    Type: Application
    Filed: June 4, 2001
    Publication date: December 6, 2001
    Inventors: Masaharu Wada, Kenji Tsuchida, Tsuneo Inaba, Atsushi Takeuchi, Toshimi Ikeda, Kuninori Kawabata