Patents by Inventor Kimimasa Imai

Kimimasa Imai 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: 11728642
    Abstract: In one embodiment, a protection circuit in a semiconductor device includes first and second transistors including gates electrically connected to a first node, and connected in series to each other between the first and second lines, third and fourth transistors including gates electrically connected to a second node between the first and second transistors, and connected in series to each other between the first and second lines, and a fifth transistor including a gate electrically connected to a third node between the third and fourth transistors, and provided between the second node and the second line. The protection circuit further includes an arithmetic circuit configured to perform calculation using a first signal received from the second node to output a second signal, and a sixth transistor configured to receive the second signal to output a control signal to the arithmetic circuit.
    Type: Grant
    Filed: September 14, 2021
    Date of Patent: August 15, 2023
    Assignee: Kioxia Corporation
    Inventors: Shigefumi Ishiguro, Yasuhiro Suematsu, Takeshi Miyaba, Kimimasa Imai, Maya Inagaki
  • Publication number: 20220285934
    Abstract: In one embodiment, a protection circuit in a semiconductor device includes first and second transistors including gates electrically connected to a first node, and connected in series to each other between the first and second lines, third and fourth transistors including gates electrically connected to a second node between the first and second transistors, and connected in series to each other between the first and second lines, and a fifth transistor including a gate electrically connected to a third node between the third and fourth transistors, and provided between the second node and the second line. The protection circuit further includes an arithmetic circuit configured to perform calculation using a first signal received from the second node to output a second signal, and a sixth transistor configured to receive the second signal to output a control signal to the arithmetic circuit.
    Type: Application
    Filed: September 14, 2021
    Publication date: September 8, 2022
    Applicant: Kioxia Corporation
    Inventors: Shigefumi ISHIGURO, Yasuhiro SUEMATSU, Takeshi MIYABA, Kimimasa IMAI, Maya INAGAKI
  • Patent number: 8837240
    Abstract: A memory cell array of a first semiconductor chip includes a normal cell array and a spare cell array. A first defect address data storage circuit outputs first defect address data indicating an address of a defective memory cell in the memory cell array. A first comparison circuit compares address data with the first defect address data and outputs a first match signal in case of matching. A second defect address data storage circuit outputs second defect address data indicating an address of a defective memory cell in the memory cell array. A second comparison circuit compares the address data with the second defect address data and outputs a second match signal in case of matching.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: September 16, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takayuki Iwai, Makoto Takahashi, Masaharu Wada, Mariko Iizuka, Kimimasa Imai
  • Patent number: 8675431
    Abstract: A memory cell array of a first semiconductor chip includes a normal cell array and a spare cell array. A first defect address data output circuit outputs first defect address data indicating an address of a defective memory cell in the memory cell array. A first comparison circuit compares address data with the first defect address data and outputs a first match signal in case of matching. A second defect address data output circuit outputs second defect address data indicating an address of a defective memory cell in the memory cell array. A second comparison circuit compares the address data with the second defect address data and outputs a second match signal in case of matching.
    Type: Grant
    Filed: March 20, 2012
    Date of Patent: March 18, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takayuki Iwai, Makoto Takahashi, Masaharu Wada, Mariko Iizuka, Kimimasa Imai
  • Publication number: 20130077420
    Abstract: A memory cell array of a first semiconductor chip includes a normal cell array and a spare cell array. A first defect address data storage circuit outputs first defect address data indicating an address of a defective memory cell in the memory cell array. A first comparison circuit compares address data with the first defect address data and outputs a first match signal in case of matching. A second defect address data storage circuit outputs second defect address data indicating an address of a defective memory cell in the memory cell array. A second comparison circuit compares the address data with the second defect address data and outputs a second match signal in case of matching.
    Type: Application
    Filed: September 14, 2012
    Publication date: March 28, 2013
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Takayuki Iwai, Makoto Takahashi, Masaharu Wada, Mariko Iizuka, Kimimasa Imai
  • Publication number: 20130051167
    Abstract: A memory cell array of a first semiconductor chip includes a normal cell array and a spare cell array. A first defect address data output circuit outputs first defect address data indicating an address of a defective memory cell in the memory cell array. A first comparison circuit compares address data with the first defect address data and outputs a first match signal in case of matching. A second defect address data output circuit outputs second defect address data indicating an address of a defective memory cell in the memory cell array. A second comparison circuit compares the address data with the second defect address data and outputs a second match signal in case of matching.
    Type: Application
    Filed: March 20, 2012
    Publication date: February 28, 2013
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Takayuki Iwai, Makoto Takahashi, Masaharu Wada, Mariko Iizuka, Kimimasa Imai
  • Patent number: 7646657
    Abstract: A semiconductor memory device includes a memory cell array, word line, row decoder, bit line, sense amplifier, dummy cell array, dummy bit line, sense amplifier activation circuit, and signal interconnection. The word line is connected to memory cells arrayed in the column direction. The row decoder is connected to the word line. The bit line is connected to memory cells arrayed in the row direction. The sense amplifier is connected to the bit line. Dummy cells are arrayed in the row direction between the row decoder and the memory cell array. The dummy bit line is connected to the dummy cells. The sense amplifier activation circuit transmits a sense start signal for setting a sense start timing to the sense amplifier through the signal interconnection. In this arrangement, the signal delay of the word line is set to be equal to that of the signal interconnection.
    Type: Grant
    Filed: November 27, 2007
    Date of Patent: January 12, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Kimimasa Imai
  • Patent number: 7433259
    Abstract: A basic unit block has a plurality of memory cells, a local bit line pair connected to the plurality of memory cells, and a bit line precharge circuit and a transfer gate switch circuit which are connected to the local bit line pair. The local bit line pairs in a plurality of basic unit blocks are connected to a global bit line pair via the transfer gate switch circuit. The global bit line pair constitutes a layered bit line structure together with the local bit line pair. The global bit line pair is laid out to extend in the same direction and is twisted once or more in this extending direction.
    Type: Grant
    Filed: August 22, 2006
    Date of Patent: October 7, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kimimasa Imai, Tomoaki Yabe
  • Publication number: 20080123387
    Abstract: A semiconductor memory device includes a memory cell array, word line, row decoder, bit line, sense amplifier, dummy cell array, dummy bit line, sense amplifier activation circuit, and signal interconnection. The word line is connected to memory cells arrayed in the column direction. The row decoder is connected to the word line. The bit line is connected to memory cells arrayed in the row direction. The sense amplifier is connected to the bit line. Dummy cells are arrayed in the row direction between the row decoder and the memory cell array. The dummy bit line is connected to the dummy cells. The sense amplifier activation circuit transmits a sense start signal for setting a sense start timing to the sense amplifier through the signal interconnection. In this arrangement, the signal delay of the word line is set to be equal to that of the signal interconnection.
    Type: Application
    Filed: November 27, 2007
    Publication date: May 29, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Kimimasa IMAI
  • Publication number: 20070047368
    Abstract: A basic unit block has a plurality of memory cells, a local bit line pair connected to the plurality of memory cells, and a bit line precharge circuit and a transfer gate switch circuit which are connected to the local bit line pair. The local bit line pairs in a plurality of basic unit blocks are connected to a global bit line pair via the transfer gate switch circuit. The global bit line pair constitutes a layered bit line structure together with the local bit line pair. The global bit line pair is laid out to extend in the same direction and is twisted once or more in this extending direction.
    Type: Application
    Filed: August 22, 2006
    Publication date: March 1, 2007
    Inventors: Kimimasa Imai, Tomoaki Yabe
  • Patent number: 6920070
    Abstract: At a Power-On time, a read potential is generated by a VBP generating circuit (Power-On). The read potential is applied as VBP to a program element to check the state of the program element. The read potential is produced from, e.g. a logic power supply potential. At a program time, a program potential is generated by a VBP generating circuit (Program). The program potential is supplied, for example, from the outside of the chip. The program potential is applied as VBP to the program element. While the read/program potential is being output, the gate of a barrier transistor is supplied with VBT, e.g. a power supply potential.
    Type: Grant
    Filed: September 25, 2003
    Date of Patent: July 19, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Kimimasa Imai
  • Publication number: 20050013188
    Abstract: At a Power-On time, a read potential is generated by a VBP generating circuit (Power-On). The read potential is applied as VBP to a program element to check the state of the program element. The read potential is produced from, e.g. a logic power supply potential. At a program time, a program potential is generated by a VBP generating circuit (Program). The program potential is supplied, for example, from the outside of the chip. The program potential is applied as VBP to the program element. While the read/program potential is being output, the gate of a barrier transistor is supplied with VBT, e.g. a power supply potential.
    Type: Application
    Filed: September 25, 2003
    Publication date: January 20, 2005
    Inventor: Kimimasa Imai
  • Patent number: 6081468
    Abstract: To suppress the power-on current flowing when power is tuned on in the circuit which feeds precharging current to the bit lines of the banks in a synchronous DRAM comprising a multi-bank structure. The device comprises a plurality of bank circuits BKi which are all of the same structure, wherein the bit line precharging power supply lines which the respective bank circuits have are connected in common, a first precharging power supply circuit which has its output node connected to the precharging power supply line and starts its precharging current feed operation when the power supply in the DRAM chip is turned on, and a second precharging power supply circuit which has its output node connected to the precharging power supply line and starts its precharging current feed operation after the bit line has been raised to a predetermined potential by the precharging current of the first precharging power supply circuit.
    Type: Grant
    Filed: July 15, 1999
    Date of Patent: June 27, 2000
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takashi Taira, Kimimasa Imai
  • Patent number: 5424984
    Abstract: A read-write semiconductor memory comprises a first data input buffer which takes in external data and which has a pair of signal output nodes for outputting a pair of signals corresponding to the taken-in data, a pair of signal lines connected to a pair of signal output nodes of the first data input buffer, and second data input buffers which are connected to the pair of signal lines and which have internal data set according to the signals on the pair of signal lines.
    Type: Grant
    Filed: March 4, 1994
    Date of Patent: June 13, 1995
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yousei Nagahama, Kimimasa Imai
  • Patent number: 5404336
    Abstract: The parity cell arrays are placed between the ordinary cell arrays and a second peripheral circuit. Data signal lines are provided between the ordinary cell arrays, between the ordinary cell arrays and the parity cell arrays, and between the parity cell arrays. These data signal lines are connected to read-write lines via data signal-line amplifier circuits. These data column-line amplifier circuits have almost the same construction. The data signal-line control circuit activates the data signal-line amplifier circuits during a write and a read operation to enable data transfer between the data signal lines and the read-write lines.
    Type: Grant
    Filed: September 16, 1993
    Date of Patent: April 4, 1995
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Kimimasa Imai
  • Patent number: 4849653
    Abstract: There is an R-S flip-flop circuit having a threshold voltage of a first value. An input terminal of a Schmitt trigger circuit having a second threshold voltage of a lower value than the first value and a third threshold voltage of a higher value than the first value is connected to an output terminal of the R-S flip-flop circuit.
    Type: Grant
    Filed: March 8, 1988
    Date of Patent: July 18, 1989
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kimimasa Imai, Hiroshi Shinya