Patents by Inventor Daisaburo Takashima

Daisaburo Takashima 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: 8134349
    Abstract: A power supply circuit has a constant voltage circuit, a first MOS transistor, a second MOS transistor, a third MOS transistor, a first voltage dividing circuit that outputs a first divided voltage obtained by dividing the voltage of the output terminal by a first voltage dividing ratio, and a first differential amplifier circuit which is fed with a reference voltage and the first divided voltage and has an output connected to a gate of the second MOS transistor. The first differential amplifier circuit outputs a signal to turn on the second MOS transistor when the first divided voltage is higher than the reference voltage, and the first differential amplifier circuit outputs a signal to turn off the second MOS transistor when the first divided voltage is lower than the reference voltage.
    Type: Grant
    Filed: March 16, 2009
    Date of Patent: March 13, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hidehiro Shiga, Shinichiro Shiratake, Daisaburo Takashima
  • Patent number: 8134855
    Abstract: A driver circuit and a precharge circuit apply, in a test mode, a fixed potential to a bit-line, while applying a second plate-line voltage to a plate-line. Then, the bit-line is switched from a first bit-line precharge potential to a floating state, and the plate-line voltage is raised from the second plate-line voltage to a plate-line voltage.
    Type: Grant
    Filed: March 13, 2009
    Date of Patent: March 13, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ryu Ogiwara, Daisaburo Takashima
  • Publication number: 20120060066
    Abstract: This disclosure concerns a memory including: a first memory region including memory groups including a plurality of memory cells, addresses being respectively allocated for the memory groups, the memory groups respectively being units of data erase operations; a second memory region temporarily storing therein data read from the first memory region or temporarily storing therein data to be written to the first memory region; a read counter storing therein a data read count for each memory group; an error-correcting circuit calculating an error bit count of the read data; and a controller performing a refresh operation, in which the read data stored in one of the memory groups is temporarily stored in the second memory region and is written back the read data to the same memory group, when the error bit count exceeds a first threshold or when the data read count exceeds a second threshold.
    Type: Application
    Filed: November 16, 2011
    Publication date: March 8, 2012
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Yasushi Nagadomi, Daisaburo Takashima, Kosuke Hatsuda
  • Patent number: 8116112
    Abstract: A semiconductor memory apparatus includes: a bit line; a word line; a local bit line; a first switch unit provided between the local bit line and the bit; a memory cell connected to the bit line and the word line; a memory cell array including the memory cell; a first sense circuit connected to the bit line and configured to amplify a signal read out from the memory cell; and a second sense circuit connected to the local bit lines and configured to amplify a signal amplified by the first sense circuit, wherein the first switch unit disconnects the local bit line from the bit line when the first sense circuit amplifies the signal, and connects the local bit line to the bit line when the second sense circuit amplifies the signal amplified by the first sense circuit.
    Type: Grant
    Filed: September 2, 2009
    Date of Patent: February 14, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tadashi Miyakawa, Daisaburo Takashima
  • Patent number: 8094479
    Abstract: A memory includes ferroelectric capacitors; sense amplifiers configured to detect the data stored in ferroelectric capacitors; and a plate control circuit configured to receive a plate driving signal driving a plate line, a write signal indicating writing of data from an outside to the sense amplifier, and an operation end signal indicating end of an executable period for reading or writing data between the sense amplifier and the outside, the plate control circuit validating or invalidating the plate driving signal based on the write signal and the operation end signal wherein the plate control circuit validates the plate driving signal in the executable period, and the plate control circuit invalidates the plate driving signal at the end of the executable period when the write signal is never activated in the executable period, and keeps the plate driving signal valid when the write signal is activated in the executable period.
    Type: Grant
    Filed: January 8, 2010
    Date of Patent: January 10, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hidehiro Shiga, Daisaburo Takashima
  • Patent number: 8078923
    Abstract: This disclosure concerns a memory including: a first memory region including memory groups including a plurality of memory cells, addresses being respectively allocated for the memory groups, the memory groups respectively being units of data erase operations; a second memory region temporarily storing therein data read from the first memory region or temporarily storing therein data to be written to the first memory region; a read counter storing therein a data read count for each memory group; an error-correcting circuit calculating an error bit count of the read data; and a controller performing a refresh operation, in which the read data stored in one of the memory groups is temporarily stored in the second memory region and is written back the read data to the same memory group, when the error bit count exceeds a first threshold or when the data read count exceeds a second threshold.
    Type: Grant
    Filed: September 30, 2008
    Date of Patent: December 13, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yasushi Nagadomi, Daisaburo Takashima, Kosuke Hatsuda
  • Patent number: 8064240
    Abstract: A memory includes word lines; plate lines; first to eighth bit lines; cell transistors; ferroelectric capacitor connected in parallel with cell transistors; sense amplifiers, wherein cell transistors and ferroelectric capacitors configure cells, the cells are connected in series to configure first to eighth cell blocks, the cell blocks are connected to the same word lines, first ends of the cell blocks are respectively connected to the bit lines, second ends of the cell blocks are respectively connected to the different plate lines, one of the first to the fourth bit lines and one of the fifth to the eighth bit lines are configured to be selectively connected to the sense amplifier during an operation, numbers of the cells connected in series between the bit lines and the plate lines are different in the first to the fourth cell blocks, and are different in the fifth to the eighth cell blocks.
    Type: Grant
    Filed: July 14, 2009
    Date of Patent: November 22, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Daisaburo Takashima
  • Patent number: 8059445
    Abstract: A ferroelectric memory according to an embodiment of the present invention includes a memory cell array including plural memory cells, and provided with plural word lines, plural bit lines, and plural plate lines, each of the plate lines corresponding to at least two of the word lines, an access control circuit configured to perform an access operation to a selected cell which is selected from the memory cells, and a refresh control circuit configured to perform a refresh operation, in a background of the access operation, on a refresh cell which is selected from the memory cells, the refresh control circuit performing the refresh operation when a plate line connected to the selected cell and a bit line connected to the selected cell are at the same potential after the access operation.
    Type: Grant
    Filed: September 21, 2009
    Date of Patent: November 15, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Daisuke Hashimoto, Daisaburo Takashima, Hidehiro Shiga
  • Patent number: 8045358
    Abstract: According to an aspect of the present invention, there is provided a nonvolatile semiconductor memory device including: a memory cell array including: memory cell blocks each having series-connected memory cells; wordlines; and a bitline pair connected to the memory cell blocks, one functioning as a readout bitline, the other one functioning as a reference bitline; an amplification circuit connected to the bitline pair to amplify a signal difference therebetween; and a reference voltage generation circuit including: a dummy memory cell block that has the same configuration as the memory cell block, that has one terminal connected to a first dummy plate line and that has the other terminal connected to the reference bitline; and a paraelectric capacitor that has one terminal connected to a second dummy plate line and that has the other terminal connected to the reference bitline.
    Type: Grant
    Filed: December 10, 2009
    Date of Patent: October 25, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ryu Ogiwara, Daisaburo Takashima
  • Patent number: 8045357
    Abstract: A memory includes a memory cell array including destructive read-out type memory cells; a decoder selecting a cell; a sense amplifier configured to detect the data; and a read and write controller controlling a read operation and a write operation, wherein the read and write controller outputs a logical value of a write enable signal at the start of the read operation in a first period and makes the write enable signal invalid after the read operation starts during the first period, on the basis of the write enable signal and a restore signal keeping an activated state during the first period, the write enable signal being a signal allowing the write operation, the first period being a period from when the read operation starts to when a restore operation for writing the data back to the memory cell is completed.
    Type: Grant
    Filed: September 3, 2009
    Date of Patent: October 25, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ryu Ogiwara, Daisaburo Takashima
  • Patent number: 8036021
    Abstract: A memory cell array includes a plurality of memory cells arranged at intersections of bit line pairs and word lines. Each memory cell includes a first transistor having one main electrode connected to a first bit line, a second transistor having one main electrode connected to a second bit line, a first node electrode for data-storage connected to the other main electrode of the first transistor, a second node electrode for data-storage connected to the other main electrode of the second transistor, and a shield electrode formed surrounding the first and second node electrodes. The first and second transistors have respective gates both connected to an identical word line, and the first and second bit lines are connected to an identical sense amp. The first and second node electrodes, the first and second bit lines, the word line and the shield electrode are isolated from each other using insulating films.
    Type: Grant
    Filed: November 18, 2009
    Date of Patent: October 11, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ryo Fukuda, Daisaburo Takashima
  • Patent number: 8031507
    Abstract: The sense amplifier detects and amplifies a signal read via bit lines from the ferroelectric capacitor of the memory cell. The dummy capacitor provides a reference voltage to bit lines. The dummy capacitor includes a first dummy capacitor and a second dummy capacitor. The first dummy capacitor is provided with a first dummy plate potential at one end to set the reference voltage to a certain potential. The other end is connected to the bit line. The second dummy capacitor is provided with a second dummy plate potential at one end to fine-tune the reference voltage from the certain potential. The other end thereof is connected to the bit line.
    Type: Grant
    Filed: July 28, 2009
    Date of Patent: October 4, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Sumiko Doumae, Daisaburo Takashima
  • Publication number: 20110234306
    Abstract: In a booster, a first transistor of a second conduction-type is formed on a first conduction-type substrate and connected to between a voltage-source and an output so that the first transistor functions as a diode. A first capacitor is connected to a first node of the first transistor on a voltage-source side, and transmits a first clock to the first node. A second transistor of the first conduction-type is connected to a second node of the first transistor on an output side to receive the first clock. A second capacitor is connected to the second node and transmits a second clock having an opposite phase of the first clock to the second node. The first transistor transfers the first node's voltage stepped up by the first clock to the second node. The second transistor transfers the second node's voltage stepped up by the second clock to an output side.
    Type: Application
    Filed: March 14, 2011
    Publication date: September 29, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Takeshi HIOKA, Daisaburo Takashima
  • Publication number: 20110228603
    Abstract: According to one embodiment, there is provided a fusion memory including a first memory cell array formed of a NAND cell unit and a second memory cell array formed of a DRAM cell on a semiconductor substrate. The NAND cell unit is formed of a non-volatile memory cell having a two-layer gate structure in which a first gate and a second gate are stacked, and a selective transistor connecting the first and second gates of the non-volatile memory cell. The DRAM cell is formed of a cell transistor having a structure same as the structure of the selective transistor, and a MOS capacitor having a structure same as the structure of the non-volatile memory cell or the selective transistor.
    Type: Application
    Filed: March 16, 2011
    Publication date: September 22, 2011
    Inventor: Daisaburo TAKASHIMA
  • Patent number: 7990791
    Abstract: A memory includes a cell array; bit lines; word lines; sense amplifiers; first determination transistors receiving information data and making a connection between a first voltage source and a first determination node be in a conductive or a non-conductive state based on a logic value of the information data; second determination transistors receiving the information data detected by the sense amplifiers and making a connection between the first voltage source and a second determination node be in a conductive or a non-conductive state based on the logic value of the information data; a second voltage source charging the first and the second determination nodes; and a determination unit detecting potentials of the first determination node and the second determination node when a logic of the information data is inverted logically to determine maximum and minimum values of potential of the information data.
    Type: Grant
    Filed: July 21, 2009
    Date of Patent: August 2, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tadashi Miyakawa, Daisaburo Takashima
  • Patent number: 7990750
    Abstract: A ferroelectric memory of an embodiment of the present invention includes m platelines arranged in a first interconnect layer (m is a positive integer), n bitlines arranged in a second interconnect layer (n is a positive integer), and m×n memory cells arranged at m×n intersection points of the m platelines and the n bitlines, each of the m×n memory cells including a ferroelectric capacitor and a zener diode connected in series between any one of the m platelines and any one of the n bitlines.
    Type: Grant
    Filed: September 21, 2009
    Date of Patent: August 2, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hidehiro Shiga, Daisaburo Takashima
  • Patent number: 7965536
    Abstract: According to an aspect of the present invention, there is provided a ferroelectric memory device including: a cell unit including: a first select transistor having a first source, a first drain, and a first gate, one of the first source and the first drain being connected to a bit line; and a memory cell unit having a plurality of first memory cells, each of the first memory cells including a first ferroelectric capacitor and a first memory transistor; and a ferroelectric memory fuse including: a second select transistor having a second source, a second drain, and a second gate connected to a second select line, one of the second source and the second drain being connected to one end of the bit line; and a memory fuse unit having a plurality of second memory cells, each of the second memory cells including a second ferroelectric capacitor and a second memory transistor.
    Type: Grant
    Filed: September 15, 2009
    Date of Patent: June 21, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Daisuke Hashimoto, Daisaburo Takashima, Hidehiro Shiga
  • Patent number: 7911821
    Abstract: A ferroelectric memory is provided with a voltage generating circuit configured to generate prescribed driving potential, a driving interconnection to which the driving potential is applied, a plurality of memory cells connected to the driving interconnections and an internal voltage comparison circuit configured to compare inputted potential and to output results thereof. A plurality of voltage monitoring interconnections are provided to connect between a portion of the driving interconnection disposed at a position distant from the voltage generating circuit on the substrate and the internal voltage comparison circuit. The internal voltage comparison circuit compares potential inputted through the voltage monitoring interconnection with the driving potential.
    Type: Grant
    Filed: July 20, 2009
    Date of Patent: March 22, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Sumiko Doumae, Daisaburo Takashima
  • Publication number: 20110063886
    Abstract: A memory includes a cell region; a spare region including a spare block; a fuse region storing remedy information necessary for an access to the spare block instead of a remedy target block, the fuse region comprising non-defective cells in the remedy target block, or including cells in a first block of the spare region; an initial reading fuse storing a block address for identifying the remedy target block or the first block allocated as the fuse region, and a selection address for selecting a region in the remedy target block or a region in the first block allocated as the fuse region; and a controller configured to acquire the remedy information from the fuse region based on the block address and the selection address, and to change the access to the remedy target block to the access to the spare block based on the remedy information.
    Type: Application
    Filed: February 10, 2010
    Publication date: March 17, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Daisuke HASHIMOTO, Daisaburo TAKASHIMA
  • Publication number: 20110058403
    Abstract: A ferro-electric random access memory apparatus has a memory cell array in which a plurality of memory cells each formed of a ferro-electric capacitor and a transistor are arranged, word lines are disposed to select a memory cell, plate lines are disposed to apply a voltage to a first end of the ferro-electric capacitor in a memory cell, and bit lines are disposed to read cell data from a second end of the ferro-electric capacitor in the memory cell. The ferro-electric random access memory apparatus has a sense amplifier which senses and amplifies a signal read from the ferro-electric capacitor onto the bit line. The ferro-electric random access memory apparatus has a bit line potential control circuit which exercises control to pull down a voltage on an adjacent bit line adjacent to the selected bit line onto which the signal is read, before operation of the sense amplifier at time of data readout.
    Type: Application
    Filed: September 7, 2010
    Publication date: March 10, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Daisuke HASHIMOTO, Daisaburo TAKASHIMA