Patents by Inventor Kenichi Imamiya

Kenichi Imamiya 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: 20100309724
    Abstract: A semiconductor memory device has a memory cell array, a first transistor of a first conductivity type, a second transistor of a second conductivity type and a third transistor of the first conductivity type. A source or drain of the first transistor is connected to each of word lines. A drain of the second transistor is connected to a gate of the first transistor. A source of the third transistor is connected to the gate of the first transistor. The gates of the second transistor and the third transistor are not connected, a source of the second transistor is not connected to a drain of the third transistor, and the gate of the second transistor and the drain of the third transistor have different voltage levels corresponding to opposite logic levels each other.
    Type: Application
    Filed: August 16, 2010
    Publication date: December 9, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hiroshi Nakamura, Kenichi Imamiya
  • Publication number: 20100277984
    Abstract: In an EEPROM consisting of a NAND cell in which a plurality of memory cells are connected in series, the control gate voltage Vread of the memory cell in a block selected by the data read operation is made different from the each of the voltages Vsg1, Vsg2 of the select gate of the select transistor in the selected block so as to make it possible to achieve a high speed reading without bringing about the breakdown of the insulating film interposed between the select gate and the channel of the select transistor. The high speed reading can also be made possible in the DINOR cell, the AND cell, NOR cell and the NAND cell having a single memory cell connected thereto, if the control gate voltage of the memory cell is made different from the voltage of the select gate of the select transistor.
    Type: Application
    Filed: July 9, 2010
    Publication date: November 4, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hiroshi Nakamura, Kenichi Imamiya
  • Patent number: 7800973
    Abstract: A semiconductor memory device has a memory cell array, a first transistor of a first conductivity type, a second transistor of a second conductivity type and a third transistor of the first conductivity type. A source or drain of the first transistor is connected to each of word lines. A drain of the second transistor is connected to a gate of the first transistor. A source of the third transistor is connected to the gate of the first transistor. The gates of the second transistor and the third transistor are not connected, a source of the second transistor is not connected to a drain of the third transistor, and the gate of the second transistor and the drain of the third transistor have different voltage levels corresponding to opposite logic levels each other.
    Type: Grant
    Filed: July 16, 2009
    Date of Patent: September 21, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Nakamura, Kenichi Imamiya
  • Patent number: 7787277
    Abstract: A semiconductor memory device capable of preventing a defect caused by lowering the etching precision in an end area of the memory cell array is provided. A first block is constructed by first memory cell units each having of memory cells, a second block is constructed by second memory cell units each having a plurality of memory cells, and the memory cell array is constructed by arranging the first blocks on both end portions thereof and arranging the second blocks on other portions thereof. The structure of the first memory cell unit on the end side of the memory cell array is different from that of the second memory cell unit. Wirings for connecting the selection gate lines of the memory cell array to corresponding transistors in a row decoder are formed of wiring layers formed above wirings for connecting control gate lines of the memory cell array to the transistors in the row decoder.
    Type: Grant
    Filed: March 21, 2008
    Date of Patent: August 31, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Nakamura, Ken Takeuchi, Hideko Oodaira, Kenichi Imamiya, Kazuhito Narita, Kazuhiro Shimizu, Seiichi Aritome
  • Patent number: 7768057
    Abstract: In an EEPROM consisting of a NAND cell in which a plurality of memory cells are connected in series, the control gate voltage Vread of the memory cell in a block selected by the data read operation is made different from the each of the voltages Vsg1, Vsg2 of the select gate of the select transistor in the selected block so as to make it possible to achieve a high speed reading without bringing about the breakdown of the insulating film interposed between the select gate and the channel of the select transistor. The high speed reading can also be made possible in the DINOR cell, the AND cell, NOR cell and the NAND cell having a single memory cell connected thereto, if the control gate voltage of the memory cell is made different from the voltage of the select gate of the select transistor.
    Type: Grant
    Filed: January 4, 2008
    Date of Patent: August 3, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Nakamura, Kenichi Imamiya
  • Patent number: 7751259
    Abstract: One package contains a plurality of memory chips. Each memory chip has an I/O terminal which generates a busy signal. The busy signal enables a busy state when a power supply voltage value reaches a specified and guaranteed range after a power-on sequence. The busy signal maintains the busy state until completion of initialization operations for the plurality of memory chips. The busy signal releases the busy state after completion of all initialization operations for the plurality of memory chips.
    Type: Grant
    Filed: September 27, 2007
    Date of Patent: July 6, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Nakamura, Kenichi Imamiya, Ken Takeuchi
  • Publication number: 20100091570
    Abstract: A memory cell array has a structure in which a plurality of memory cells connected with word lines and bit lines and connected in series are arranged in a matrix form. A selection transistor selects the word lines. A control circuit controls potentials of the word lines and the bit lines in accordance with input data, and controls write, read and erase operations of data with respect to the memory cell. The selection transistor is formed on a well, and a first negative voltage is supplied to a well, a first voltage (the first voltage?the first negative voltage) is supplied to a selected word line and a second voltage is supplied to a non-selected word line in the read operation.
    Type: Application
    Filed: December 18, 2009
    Publication date: April 15, 2010
    Inventors: Noboru SHIBATA, Kenichi IMAMIYA
  • Publication number: 20100061149
    Abstract: A non-volatile semiconductor device has a memory cell array having electrically erasable programmable non-volatile memory cells, reprogramming and retrieval circuits that temporarily store data to be programmed in the memory cell array and sense data retrieved from the memory cell array. Each reprogramming and retrieval circuit has first and second latches that are selectively connected to the memory cell array and transfer data. A controller controls the reprogramming and retrieval circuits on a data-reprogramming operation to and a data-retrieval operation from the memory cell array. Each reprogramming and retrieval circuit has a multilevel logical operation mode and a caching operation mode. In the multilevel logical operation mode, re-programming and retrieval of upper and lower bits of two-bit four-level data is performed using the first and the second latches to store the two-bit four-level data in one of the memory cells in a predetermined threshold level range.
    Type: Application
    Filed: November 18, 2009
    Publication date: March 11, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Koji Hosono, Hiroshi Nakamura, Ken Takeuchi, Kenichi Imamiya
  • Patent number: 7663919
    Abstract: A memory cell array has a structure in which a plurality of memory cells connected with word lines and bit lines and connected in series are arranged in a matrix form. A selection transistor selects the word lines. A control circuit controls potentials of the word lines and the bit lines in accordance with input data, and controls write, read and erase operations of data with respect to the memory cell. The selection transistor is formed on a well, and a first negative voltage is supplied to a well, a first voltage (the first voltage?the first negative voltage) is supplied to a selected word line and a second voltage is supplied to a non-selected word line in the read operation.
    Type: Grant
    Filed: July 7, 2008
    Date of Patent: February 16, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Noboru Shibata, Kenichi Imamiya
  • Patent number: 7663967
    Abstract: One package contains a plurality of memory chips. Each memory chip has an I/O terminal which generates a busy signal. The busy signal enables a busy state when a power supply voltage value reaches a specified and guaranteed range after a power-on sequence. The busy signal maintains the busy state until completion of initialization operations for the plurality of memory chips. The busy signal releases the busy state after completion of all initialization operations for the plurality of memory chips.
    Type: Grant
    Filed: October 5, 2007
    Date of Patent: February 16, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Nakamura, Kenichi Imamiya, Ken Takeuchi
  • Patent number: 7639544
    Abstract: A non-volatile semiconductor device has a memory cell array having electrically erasable programmable non-volatile memory cells, reprogramming and retrieval circuits that temporarily store data to be programmed in the memory cell array and sense data retrieved from the memory cell array. Each reprogramming and retrieval circuit has first and second latches that are selectively connected to the memory cell array and transfer data. A controller controls the reprogramming and retrieval circuits on a data-reprogramming operation to and a data-retrieval operation from the memory cell array. Each reprogramming and retrieval circuit has a multilevel logical operation mode and a caching operation mode. In the multilevel logical operation mode, re-programming and retrieval of upper and lower bits of two-bit four-level data is performed using the first and the second latches to store the two-bit four-level data in one of the memory cells in a predetermined threshold level range.
    Type: Grant
    Filed: October 24, 2008
    Date of Patent: December 29, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Hosono, Hiroshi Nakamura, Ken Takeuchi, Kenichi Imamiya
  • Patent number: 7633826
    Abstract: A semiconductor device of this invention includes a first circuit for initializing a predetermined circuit in accordance with the level of a power source voltage, a second circuit for controlling the output from the first circuit by activation or deactivation, and an activation control circuit for activating or deactivating the second circuit in accordance with external input.
    Type: Grant
    Filed: November 12, 2007
    Date of Patent: December 15, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazushige Kanda, Kenichi Imamiya, Hiroshi Nakamura, Ken Takeuchi, Tamio Ikehashi
  • Publication number: 20090290419
    Abstract: A semiconductor memory device has a memory cell array, a first transistor of a first conductivity type, a second transistor of a second conductivity type and a third transistor of the first conductivity type. A source or drain of the first transistor is connected to each of word lines. A drain of the second transistor is connected to a gate of the first transistor. A source of the third transistor is connected to the gate of the first transistor. The gates of the second transistor and the third transistor are not connected, a source of the second transistor is not connected to a drain of the third transistor, and the gate of the second transistor and the drain of the third transistor have different voltage levels corresponding to opposite logic levels each other.
    Type: Application
    Filed: July 16, 2009
    Publication date: November 26, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hiroshi Nakamura, Kenichi Imamiya
  • Patent number: 7619921
    Abstract: A non-volatile semiconductor memory includes a memory cell array having a plurality of electrically-rewritable non-volatile memory cells. The memory cell array is provided with an initially-setting data area, programmed in which is initially-setting data for deciding memory operation requirements. The non-volatile semiconductor memory also includes an initial-set data latch. The initially-setting data of the memory cell array is read out and transferred to the data latch in an initially-setting operation.
    Type: Grant
    Filed: September 11, 2006
    Date of Patent: November 17, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Hosono, Toshihiko Himeno, Kenichi Imamiya, Hiroshi Nakamura
  • Patent number: 7596042
    Abstract: One package contains a plurality of memory chips. Each memory chip has an I/O terminal which generates a busy signal. The busy signal enables a busy state when a power supply voltage value reaches a specified and guaranteed range after a power-on sequence. The busy signal maintains the busy state until completion of initialization operations for the plurality of memory chips. The busy signal releases the busy state after completion of all initialization operations for the plurality of memory chips.
    Type: Grant
    Filed: October 2, 2007
    Date of Patent: September 29, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Nakamura, Kenichi Imamiya, Ken Takeuchi
  • Patent number: 7596027
    Abstract: Data read from memory cells of one page in a memory cell array that corresponds to a page address of a copy source is sensed and latched by a sense/latch circuit. The sense/latch circuit has a plurality of latch circuits, and the plurality of latch circuits is specified according to the column address. The latch circuit specified in accordance with the column address is supplied with the data to be rewritten. The latch circuit specified in accordance with its address latches the data to be rewritten, whereby rewriting of the data is performed. The data of one page after rewritten is written into the page in the memory cell array that corresponds to the page address of a copy destination.
    Type: Grant
    Filed: December 21, 2007
    Date of Patent: September 29, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koichi Kawai, Kenichi Imamiya, Hiroshi Nakamura
  • Patent number: 7586785
    Abstract: A non-volatile semiconductor memory device includes a memory cell array with electrically rewritable non-volatile memory cells laid out therein, an address selector circuit for performing memory cell selection of the memory cell array, a data read/write circuit arranged to perform data read of the memory cell array and data write to the memory cell array, and a control circuit for executing a series of copy write operations in such a manner that a data output operation of from the data read/write circuit to outside of a chip and a data write operation of from the data read/write circuit to the memory cell array are overlapped each other, the copy write operation including reading data at a certain address of the memory cell array into the data read/write circuit, outputting read data held in the read/write circuit to outside of the chip and writing write data into another address of the memory cell array, the write data being a modified version of the read data held in the data read/write circuit as externall
    Type: Grant
    Filed: January 28, 2008
    Date of Patent: September 8, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Hosono, Kenichi Imamiya, Hiroshi Nakamura
  • Patent number: 7580285
    Abstract: A semiconductor memory device has a memory cell array, a first transistor of a first conductivity type, a second transistor of a second conductivity type and a third transistor of the first conductivity type. A source or drain of the first transistor is connected to each of word lines. A drain of the second transistor is connected to a gate of the first transistor. A source of the third transistor is connected to the gate of the first transistor. The gates of the second transistor and the third transistor are not connected, a source of the second transistor is not connected to a drain of the third transistor, and the gate of the second transistor and the drain of the third transistor have different voltage levels corresponding to opposite logic levels each other.
    Type: Grant
    Filed: September 20, 2007
    Date of Patent: August 25, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Nakamura, Kenichi Imamiya
  • Patent number: 7567463
    Abstract: A non-volatile semiconductor device has a memory cell array having electrically erasable programmable non-volatile memory cells, reprogramming and retrieval circuits that temporarily store data to be programmed in the memory cell array and sense data retrieved from the memory cell array. Each reprogramming and retrieval circuit has first and second latches that are selectively connected to the memory cell array and transfer data. A controller controls the reprogramming and retrieval circuits on a data-reprogramming operation to and a data-retrieval operation from the memory cell array. Each reprogramming and retrieval circuit has a multilevel logical operation mode and a caching operation mode. In the multilevel logical operation mode, re-programming and retrieval of upper and lower bits of two-bit four-level data is performed using the first and the second latches to store the two-bit four-level data in one of the memory cells in a predetermined threshold level range.
    Type: Grant
    Filed: May 19, 2008
    Date of Patent: July 28, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Hosono, Hiroshi Nakamura, Ken Takeuchi, Kenichi Imamiya
  • Publication number: 20090161403
    Abstract: One package contains a plurality of memory chips. Each memory chip has an I/O terminal which generates a busy signal. The busy signal enables a busy state when a power supply voltage value reaches a specified and guaranteed range after a power-on sequence. The busy signal maintains the busy state until completion of initialization operations for the plurality of memory chips. The busy signal releases the busy state after completion of all initialization operations for the plurality of memory chips.
    Type: Application
    Filed: February 24, 2009
    Publication date: June 25, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hiroshi Nakamura, Kenichi Imamiya, Ken Takeuchi