Patents by Inventor Kazuhisa Kanazawa

Kazuhisa Kanazawa 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: 20110310667
    Abstract: A semiconductor memory device includes a memory cell array including a plurality of blocks each including a memory cell unit, and a selection transistor which selects the memory cell unit, and a row decoder including a first block selector and a second block selector each of which includes a plurality of transfer transistors which are formed to correspond to the plurality of blocks and arranged adjacent to each other in a word-line direction wherein the diffusion layers are formed to oppose each other in the first block selector and the second block selector, and a width between the diffusion layers of the first block selector and the second block selector adjacent to each other in the word-line direction is made larger than a width between the diffusion layers in each of the first block selector and the second block selector adjacent to each other in the word-line direction.
    Type: Application
    Filed: August 29, 2011
    Publication date: December 22, 2011
    Inventors: Makoto Iwai, Kazuhisa Kanazawa, Hiroshi Nakamura, Masaki Fujiu
  • Patent number: 8036038
    Abstract: A semiconductor memory device includes a memory cell array including a plurality of blocks each including a memory cell unit, and a selection transistor which selects the memory cell unit, and a row decoder including a first block selector and a second block selector each of which includes a plurality of transfer transistors which are formed to correspond to the plurality of blocks and arranged adjacent to each other in a word-line direction wherein the diffusion layers are formed to oppose each other in the first block selector and the second block selector, and a width between the diffusion layers of the first block selector and the second block selector adjacent to each other in the word-line direction is made larger than a width between the diffusion layers in each of the first block selector and the second block selector adjacent to each other in the word-line direction.
    Type: Grant
    Filed: November 22, 2010
    Date of Patent: October 11, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Makoto Iwai, Kazuhisa Kanazawa, Hiroshi Nakamura, Masaki Fujiu
  • Publication number: 20110063911
    Abstract: A semiconductor memory device includes a memory cell array including a plurality of blocks each including a memory cell unit, and a selection transistor which selects the memory cell unit, and a row decoder including a first block selector and a second block selector each of which includes a plurality of transfer transistors which are formed to correspond to the plurality of blocks and arranged adjacent to each other in a word-line direction wherein the diffusion layers are formed to oppose each other in the first block selector and the second block selector, and a width between the diffusion layers of the first block selector and the second block selector adjacent to each other in the word-line direction is made larger than a width between the diffusion layers in each of the first block selector and the second block selector adjacent to each other in the word-line direction.
    Type: Application
    Filed: November 22, 2010
    Publication date: March 17, 2011
    Inventors: Makoto Iwai, Kazuhisa Kanazawa, Hiroshi Nakamura, Masaki Fujiu
  • Patent number: 7859901
    Abstract: A semiconductor memory device includes a memory cell array including a plurality of blocks each including a memory cell unit, and a selection transistor which selects the memory cell unit, and a row decoder including a first block selector and a second block selector each of which includes a plurality of transfer transistors which are formed to correspond to the plurality of blocks and arranged adjacent to each other in a word-line direction wherein the diffusion layers are formed to oppose each other in the first block selector and the second block selector, and a width between the diffusion layers of the first block selector and the second block selector adjacent to each other in the word-line direction is made larger than a width between the diffusion layers in each of the first block selector and the second block selector adjacent to each other in the word-line direction.
    Type: Grant
    Filed: December 5, 2008
    Date of Patent: December 28, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Makoto Iwai, Kazuhisa Kanazawa, Hiroshi Nakamura, Masaki Fujiu
  • Publication number: 20090185423
    Abstract: A semiconductor memory device includes a memory cell array including a plurality of blocks each including a memory cell unit, and a selection transistor which selects the memory cell unit, and a row decoder including a first block selector and a second block selector each of which includes a plurality of transfer transistors which are formed to correspond to the plurality of blocks and arranged adjacent to each other in a word-line direction wherein the diffusion layers are formed to oppose each other in the first block selector and the second block selector, and a width between the diffusion layers of the first block selector and the second block selector adjacent to each other in the word-line direction is made larger than a width between the diffusion layers in each of the first block selector and the second block selector adjacent to each other in the word-line direction.
    Type: Application
    Filed: December 5, 2008
    Publication date: July 23, 2009
    Inventors: Makoto Iwai, Kazuhisa Kanazawa, Hiroshi Nakamura, Masaki Fujiu
  • Patent number: 6512702
    Abstract: A memory cell array is divided into left and right cell arrays, each of which includes a plurality of blocks. Data erase is sequentially controlled by an erase control circuit on the basis of an erase command flag incorporated into a command register and an address incorporated into an address register. Batch erase is carried out with respect to selected blocks of the right and left cell arrays. After data erase, a verify operation is carried out with respect to the erased blocks by retrieving the erased blocks simultaneously with respect to the right and left cell arrays in parallel. Thus, the time required to retrieve the selected blocks for the verify operation after data erase is shortened, so that the time required to carry out the whole data erase is shortened.
    Type: Grant
    Filed: March 30, 2000
    Date of Patent: January 28, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshio Yamamura, Yoshihisa Sugiura, Kazuhisa Kanazawa, Koji Sakui, Hiroshi Nakamura
  • Patent number: 5450361
    Abstract: There is disclosed a semiconductor memory device comprising memory cells (M11 to Mmn) for storing binary data, and first reference cells (DM11 to DMm1) and second reference cells (DM12 to DMm2) corresponding to respective two storage states of the memory cell, to make comparisons between the storage state of the memory cell and the storage states of the both reference cells at first and second sense amplifiers (1, 2) to compare outputs from the both sense amplifiers at the third sense amplifier (3) to thereby detect storage data of the memory cell. Thus, there can be provided a high speed memory device which has a less number of memory cells and of a high integration structure, and which has a little possibility of an erroneous operation in reading.
    Type: Grant
    Filed: February 16, 1994
    Date of Patent: September 12, 1995
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Iwahashi, Hiroto Nakai, Kazuhisa Kanazawa, Isao Sato
  • Patent number: 5371702
    Abstract: In response to a plurality of address signal input from the outside in sequence, an erase information inputting section controls an erase information holding section corresponding to the batch erase block to be erased so as to hold an erase information data. By repeating this operation in sequence, the erase information data are stored in the erase information holding sections corresponding to the plural batch erase blocks to be erased. Successively, on the basis of the erase information data stored in the erase information holding sections, block erasing sections are activated to erase all the nonvolatile memory cells of each of the corresponding blocks where the erase information data are held.
    Type: Grant
    Filed: March 5, 1993
    Date of Patent: December 6, 1994
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroto Nakai, Hideo Kato, Kaoru Tokushige, Masamichi Asano, Kazuhisa Kanazawa, Toshio Yamamura
  • Patent number: 5321655
    Abstract: There is disclosed a semiconductor memory device comprising memory cells (M11 to Mnn) for storing binary data, and first reference cells (DM11 to Dm1) and second reference cells (DM12 to DMm2) corresponding to respective two storage states of the memory cell, to make comparisons between the storage state of the memory cell and the storage states of the both reference cells at first and second sense amplifiers (1, 2) to compare outputs from the both sense amplifiers at the third sense amplifier (3) to thereby detect storage data of the memory cell. Thus, there can be provided a high speed memory device which has a less number of memory cells and of a high integration structure, and which has a little possibility of an erroneous operation in reading.
    Type: Grant
    Filed: August 24, 1993
    Date of Patent: June 14, 1994
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Iwahashi, Hiroto Nakai, Kazuhisa Kanazawa, Isao Sato
  • Patent number: 5258958
    Abstract: There is disclosed a semiconductor memory device comprising memory cells (M11 to Mmn) for storing binary data, and first reference cells (DM11 to DMm1) and second reference cells (DM12 to DMm2) corresponding to respective two storage states of the memory cell, to make comparisons between the storage state of the memory cell and the storage states of the both reference cells at first and second sense amplifiers (1, 2) to compare outputs from the both sense amplifiers at the third sense amplifier (3) to thereby detect storage data of the memory cell. Thus, there can be provided a high speed memory device which has a less number of memory cells and of a high integration structure, and which has a little possibility of an erroneous operation in reading.
    Type: Grant
    Filed: December 12, 1991
    Date of Patent: November 2, 1993
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Iwahashi, Hiroto Nakai, Kazuhisa Kanazawa, Isao Sato
  • Patent number: 5191552
    Abstract: In a semiconductor memory device, a first load circuit is coupled with the column lines, first dummy cells are connected to a dummy column line, a second load circuit is connected to the dummy column line, a second dummy cell is connected to the dummy column line, and a sense amplifier senses the data stored in the memory cell in accordance with a potential difference between the column line and the dummy column line. In semiconductor memory devices thus arranged, the second dummy cell is set in an on state normally. The connection of the second dummy cell with the dummy line changes a current flowing to the dummy line at the time of row line switching, thereby to hold back a rise of the reference potential at the time of the row line switching.
    Type: Grant
    Filed: May 31, 1991
    Date of Patent: March 2, 1993
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroto Nakai, Hiroshi Iwahashi, Kazuhisa Kanazawa, Shigeru Kumagai, Isao Sato
  • Patent number: 5040148
    Abstract: In a semiconductor memory device, a first load circuit is coupled with the column lines, first dummy cells are connected to a dummy column line, a second load circuit is connected to the dummy column line, a second dummy cell is connected to the dummy column line, and a sense amplifier senses the data stored in the memory cell in accordance with a potential difference between the column line and the dummy column line. In semiconductor memory devices thus arranged, the second dummy cell is set in an on state normally. The connection of the second dummy cell with the dummy line changes a current flowing to the dummy line at the time of row line switching, thereby to hold back a rise of the reference potential at the time of the row line switching.
    Type: Grant
    Filed: June 23, 1989
    Date of Patent: August 13, 1991
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroto Nakai, Hiroshi Iwahashi, Kazuhisa Kanazawa, Shigeru Kumagai, Isao Sato