Patents by Inventor Takahiko Sasaki

Takahiko Sasaki 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: 20160322102
    Abstract: A semiconductor memory device includes a memory cell array having first wires, a second wire, and memory cells connected to the first and second wires, and a control circuit that can apply writing voltages to the second wire. One of the memory cells connected to the selected second wire and a selected first wire is a selected memory cell. One of the memory cells connected to the selected second wire and an unselected first wire is a semi-selected memory cell. When writing data into the selected memory cell, the control circuit selects one from the writing voltages and applies the one writing voltage to a third wire connected to the selected second wire. The control circuit selects the one writing voltage, based on a first current flowing through the second wire when each of the memory cells connected to the selected second wire are set as semi-selected memory cells.
    Type: Application
    Filed: March 10, 2016
    Publication date: November 3, 2016
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: TAKAHIKO SASAKI
  • Publication number: 20160115421
    Abstract: A coating composition for lubrication film comprises: (A) a (meth)acrylic acid compound, the (meth)acrylate equivalent weight of which is less than or equal to 100; (B) a (meth)acrylic acid compound, the (meth)acrylate equivalent weight of which is in the range of 120 to 300; (C) a thermosetting resin and/or high energy beam-curable resin; and (D) at least one type of solid lubricant. The coating composition is capable of forming a resin film having high adhesion to the surfaces of various types of substrates by heating and/or high energy beam irradiation.
    Type: Application
    Filed: April 21, 2014
    Publication date: April 28, 2016
    Inventors: Takahiko SASAKI, Tetsuji YAMAGUCHI
  • Publication number: 20150307806
    Abstract: A coating composition for lubrication film is disclosed. The coating composition comprises (A) a high energy beam-curable resin, (B) silicone elastomer fine particles, and (C) a gum-like polysiloxane. The coating composition is capable of forming a lubrication film that suppresses the occurrence of stick-slip phenomenon, has good feel, adheres to a substrate, and has excellent followability (i.e. ability to follow the elastic transformation) to conform to deformation of the substrate.
    Type: Application
    Filed: November 20, 2013
    Publication date: October 29, 2015
    Inventors: Takahiko SASAKI, Tetsuji YAMAGUCHI
  • Publication number: 20150073743
    Abstract: According to one embodiment, a temperature sensor includes: a voltage generating part generating (2N?1)-midpoint voltages (N is a natural number equal to or larger than 2) based on a reference voltage which does not depend on a temperature; a sense part generating a temperature sensing voltage which depends on the temperature; and an arithmetic part is configured to generate N-bit temperature data by executing first to N-th operations each comparing the temperature sensing voltage with one of the (2N?1)-midpoint voltages.
    Type: Application
    Filed: March 6, 2014
    Publication date: March 12, 2015
    Applicants: SanDisk Corporation, KABUSHIKI KAISHA TOSHIBA
    Inventors: Takahiko SASAKI, Gopinath BALAKRISHNAN
  • Patent number: 8767437
    Abstract: A nonvolatile semiconductor memory device comprises a memory cell array, a control circuit, a current limiting circuit and a current suppression circuit. The memory cell array has a first line, a second line, and a memory cell arranged therein, the memory cell being connected between the first line and the second line and including a variable resistance element. The control circuit is configured to apply, via the first line and the second line, a voltage required in operation of the memory cell. The current limiting circuit is connected to the first line and configured to limit a current flowing in the memory cell to a certain limit value. The current suppression circuit is configured connectable to the second line and configured to suppress a current flowing in the second line according to a kind of operation on the memory cell.
    Type: Grant
    Filed: March 19, 2012
    Date of Patent: July 1, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Takahiko Sasaki
  • Patent number: 8730745
    Abstract: According to one embodiment, a semiconductor memory device includes a plurality of first interconnects which extend in a first direction and are arranged in a second direction perpendicular to the first direction, a plurality of second interconnects which extend in the second direction and are arranged in the first direction, and a plurality of first storage modules which are formed in regions where the first interconnects and the second interconnects cross. The semiconductor memory device further comprises a first interconnect control module which supplies a voltage to the first interconnects, detects a first current flowing in the first interconnects, and outputs a first voltage corresponding to the first current, a reference voltage generator module which generates a second voltage based on a second current, and a regulator which generates a third voltage based on the first voltage and the second voltage.
    Type: Grant
    Filed: March 23, 2012
    Date of Patent: May 20, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Takahiko Sasaki
  • Patent number: 8705266
    Abstract: According to one embodiment, a semiconductor memory device includes a plurality of first interconnects which extend in a first direction and are arranged in a second direction perpendicular to the first direction, a plurality of second interconnects which extend in the second direction and are arranged in the first direction, and memory cells formed in regions where the first and the second interconnects cross. The semiconductor memory device further includes a plurality of first drivers which apply voltages to the first interconnects, respectively, and a second driver which applies a voltage to the first drivers.
    Type: Grant
    Filed: March 23, 2012
    Date of Patent: April 22, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Takahiko Sasaki
  • Patent number: 8605485
    Abstract: According to one embodiment, a control unit multiple-selects a first line for every N lines from a plurality of first lines. N is an integer greater than or equal to one. The control unit sets the multiple-selected first lines to a selection potential, and fixes potentials of non-selected first lines at least adjacent to the multiple-selected first lines at a first timing. The control unit causes the multiple-selected first lines to be in a floating state at a second timing after the first timing. The control unit selects one second line from the plurality of second lines and sets the one second line to a forming potential at a third timing after the second timing.
    Type: Grant
    Filed: January 13, 2012
    Date of Patent: December 10, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Kanno, Takafumi Shimotori, Yoichi Minemura, Takahiko Sasaki, Takayuki Tsukamoto
  • Patent number: 8576605
    Abstract: A nonvolatile semiconductor memory device according to an embodiment includes a memory cell array configured by plural memory cells each including a variable resistor and each provided between first and second lines. A control circuit applies to a memory cell through the first and second lines a writing voltage for writing data or a reading voltage for reading data. A sense amplifier circuit senses data retained in a memory cell based on a current flowing through the first line. In a data writing operation, the control circuit applies a writing voltage to each of n number of memory cells configuring one unit such that the memory cells may be supplied with different resistance values. In a data reading operation, the sense amplifier circuit compares level relationship of the resistance values of n number of memory cells configuring one unit and reads out n! patterns of data from the one unit.
    Type: Grant
    Filed: March 18, 2011
    Date of Patent: November 5, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Takahiko Sasaki
  • Publication number: 20130250649
    Abstract: According to one embodiment, a semiconductor memory device includes a plurality of first interconnects which extend in a first direction and are arranged in a second direction perpendicular to the first direction, a plurality of second interconnects which extend in the second direction and are arranged in the first direction, and a plurality of first storage modules which are formed in regions where the first interconnects and the second interconnects cross. The semiconductor memory device further comprises a first interconnect control module which supplies a voltage to the first interconnects, detects a first current flowing in the first interconnects, and outputs a first voltage corresponding to the first current, a reference voltage generator module which generates a second voltage based on a second current, and a regulator which generates a third voltage based on the first voltage and the second voltage.
    Type: Application
    Filed: March 23, 2012
    Publication date: September 26, 2013
    Inventor: Takahiko SASAKI
  • Publication number: 20130250650
    Abstract: According to one embodiment, a semiconductor memory device includes a plurality of first interconnects which extend in a first direction and are arranged in a second direction perpendicular to the first direction, a plurality of second interconnects which extend in the second direction and are arranged in the first direction, and memory cells formed in regions where the first wring lines and the second interconnects cross. The semiconductor memory device further includes a plurality of first drivers which apply voltages to the first interconnects, respectively, and a second driver which applies a voltage to the first drivers.
    Type: Application
    Filed: March 23, 2012
    Publication date: September 26, 2013
    Inventor: Takahiko SASAKI
  • Patent number: 8503255
    Abstract: According to one embodiment, a semiconductor storage device includes a memory cell array and a control circuit. The memory cell array has memory cells arranged therein at respective intersections between a plurality of first wirings and a plurality of second wirings. Each of the memory cells has a variable resistance element. The control circuit is configured to apply a voltage to a selected one of the first wirings and to a selected one of the second wirings. The control circuit includes a plurality of charge pump circuits and a plurality of clock oscillator circuits. The charge pump circuits generate a voltage applied to the first and second wirings. Each of the clock oscillator circuits is configured to supply a clock signal to a certain number of the charge pump circuits to control the timing of operation thereof. The clock oscillator circuits are configured to output clock signals at different frequencies.
    Type: Grant
    Filed: June 18, 2010
    Date of Patent: August 6, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Takahiko Sasaki
  • Patent number: 8498141
    Abstract: A memory cell array includes a memory cell having a variable resistance element and disposed between first and second wirings. A control circuit provides a selected first wiring with a first voltage and provide a selected second wiring with a second voltage having a lower voltage value than the first voltage. A current limitation circuit controls a cell current below a first current. It includes a first current generation circuit for storing a cell current at a first point of time and generating a first current of ? times the stored cell current. It also includes a second current generation circuit for generating a second current of (?/?) times the cell current at a second point of time. A determination circuit outputs a control signal when the second current exceeds the stored current. The first current generation circuit newly stores a stored current according to the control signal.
    Type: Grant
    Filed: March 18, 2011
    Date of Patent: July 30, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takahiko Sasaki, Mizuki Uda
  • Patent number: 8493800
    Abstract: According to one embodiment, a semiconductor storage device includes a three-dimensional memory cell array, write drivers, and a program voltage control circuit. In the three-dimensional memory cell array, memory cells are three-dimensionally arranged. The write drivers are arranged to be distributed under the three-dimensional memory cell array and apply a program voltage to the memory cells during writing in the memory cells. The program voltage control circuit is arranged around the three-dimensional memory cell array and performs control for making the write drivers to generate the program voltage.
    Type: Grant
    Filed: February 4, 2011
    Date of Patent: July 23, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yuri Terada, Takahiko Sasaki
  • Patent number: 8493770
    Abstract: A semiconductor storage device includes a memory cell array including memory cells arranged at respective intersections between first wirings and second wirings. Each of the memory cells includes a rectifier element and a variable resistance element connected in series. A control circuit is configured to apply a first voltage to a selected first wiring and a second voltage lower than the first voltage to a selected second wiring so that a certain potential difference is applied to a selected memory cell positioned at an intersection between the selected first wiring and the selected second wiring. The control circuit performs a concurrent read operation to perform a read operation from plural memory cells concurrently by applying the first voltage to a plurality of the first wirings concurrently. It is possible to switch the number of the first wirings to be applied with the first voltage concurrently in the concurrent read operation.
    Type: Grant
    Filed: September 17, 2010
    Date of Patent: July 23, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Hosono, Yuri Terada, Takahiko Sasaki
  • Patent number: 8488366
    Abstract: A semiconductor memory device in accordance with an embodiment includes: a memory cell array having memory cells disposed at respective intersections of first lines and second lines; and a control circuit configured to apply a first pulse voltage multiple times to selected one of the first lines and selected one of the second lines, such that a certain potential difference is applied to a selected memory cell thereby causing transition of a resistance state. The control circuit is configured to, when the selected memory cell is not caused to undergo transition of the resistance state even after application of the first pulse voltage a certain number of times, execute a rescue operation where a second pulse voltage is applied to the selected memory cell subsequent to application of the first pulse voltage, the second pulse voltage having a pulse width longer than that of the first pulse voltage.
    Type: Grant
    Filed: March 9, 2011
    Date of Patent: July 16, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tomonori Kurosawa, Takahiko Sasaki
  • Patent number: 8451648
    Abstract: According to one embodiment, a resistance-change memory includes a memory element in which its variable resistance state corresponds to data to be stored therein, a pulse generation circuit which generates a first pulse, a second pulse, a third pulse, and a fourth pulse, the first pulse having a first amplitude which changes the resistance state of the memory element from a high- to a low-resistance state, the third pulse having a third amplitude smaller than the first amplitude to read data in the memory element, the fourth pulse having a fourth amplitude between the first amplitude and the third amplitude, and a control circuit which controls the operations of the memory element and the pulse generation circuit. The control circuit supplies the fourth pulse to the memory element after supplying the first pulse to the memory element.
    Type: Grant
    Filed: July 13, 2011
    Date of Patent: May 28, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masahiro Kamoshida, Katsuaki Sakurai, Takahiko Sasaki
  • Patent number: 8422269
    Abstract: A control circuit applies a first voltage to selected one of first lines and applies a second voltage having a voltage value smaller than that of the first voltage to selected one of second lines, such that a certain potential difference is applied across a memory cell disposed at an intersection of the selected one of the first lines and the selected one of the second lines. A current limiting circuit sets a compliance current defining an upper limit of a cell current flowing in the memory cell, and controls such that the cell current flowing in the memory cell does not exceed the compliance current. The current limiting circuit comprises a current generating circuit and a first current mirror circuit. The current generating circuit generates a first current having a current value equal to a current value of the cell current at a certain timing multiplied by a certain constant. The first current mirror circuit mirrors the first current to a current path supplying the first voltage to the first lines.
    Type: Grant
    Filed: February 23, 2011
    Date of Patent: April 16, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takahiko Sasaki, Tomonori Kurosawa
  • Patent number: 8331177
    Abstract: A semiconductor memory device includes a memory cell array, a first control circuit, and a second control circuit. The first control circuit is configured to apply a first voltage to a selected first line. The second control circuit is configured to apply a second voltage having a voltage value higher than that of the first voltage to a selected second line. The first control circuit includes a detecting circuit. The detecting circuit is configured to detect a leak current to flow from the second line to the first line through a memory cell during a forming operation for bringing the memory cell into a state that allows the memory cell to shift between a high resistance state and a low resistance state. The second control circuit includes a current supply circuit, and a compensating circuit. The current supply circuit is configured to supply a constant current to the second line during the forming operation.
    Type: Grant
    Filed: March 18, 2011
    Date of Patent: December 11, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Takahiko Sasaki
  • Patent number: 8279655
    Abstract: According to an embodiment, there are provided a non-volatile semiconductor memory device includes: a memory cell array; a control circuit performing a series of operations to each memory cell and determining, as a defective memory cell, a memory cell whose data retention property does not satisfy a criteria, the series of operations including an operation applying a first bias to the memory cell in a forward direction, and including an operation thereafter applying a second bias to the memory cell in a reverse direction; a storage unit storing an address of the defective memory cell; and an address control unit performing a control to avoid storing data in the defective memory cell whose address is stored in the storage unit.
    Type: Grant
    Filed: September 17, 2010
    Date of Patent: October 2, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Kanno, Takayuki Tsukamoto, Takahiko Sasaki, Takafumi Shimotori