Patents by Inventor Yoshinao Morikawa

Yoshinao Morikawa 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: 20040233726
    Abstract: A programming verification method of verifying programming of a nonvolatile memory cell, the method comprising at least the steps of: selecting first, second, . . . and n-th references corresponding to first, second, . . . and n-th threshold voltages specifying lower limit values of states 1, 2, . . .
    Type: Application
    Filed: May 19, 2004
    Publication date: November 25, 2004
    Inventors: Yasuaki Iwase, Yoshifumi Yaoi, Hiroshi Iwata, Akihide Shibata, Yoshinao Morikawa, Masaru Nawaki
  • Publication number: 20040233725
    Abstract: A method for programming a nonvolatile memory cell includes the steps of: applying a first pulse to a nonvolatile memory cell to accumulate a first amount of charge which is smaller than a target amount of charge; in the case where the accumulated first amount of charge is smaller than a second amount of charge, applying a second pulse train to the nonvolatile memory cell, so that charges in an amount close to the second amount of charge are accumulated in the nonvolatile memory cell; when the nonvolatile memory cell is determined as retaining charges larger than the second amount of charge, applying a third pulse train until charges within an allowable error range of the target amount of charge is stored in the memory cell.
    Type: Application
    Filed: May 18, 2004
    Publication date: November 25, 2004
    Inventors: Yasuaki Iwase, Yoshifumi Yaoi, Hiroshi Iwata, Akihide Shibata, Yoshinao Morikawa, Masaru Nawaki
  • Publication number: 20040233731
    Abstract: A semiconductor memory device includes a memory array; a storage section that receives a maximum pulse value from a user of the semiconductor memory device; a control section that executes a writing processing or an erasing processing for the memory array and restarts the writing or erasing processing in the case where the processing for the memory array has failed; a counter section that counts up a number of processings performed by the control section; and a detection section that detects when the number of processings is equal to the maximum pulse value to prevent the control section from restarting the writing or erasing processing.
    Type: Application
    Filed: May 18, 2004
    Publication date: November 25, 2004
    Inventors: Yoshifumi Yaoi, Hiroshi Iwata, Akihide Shibata, Yoshinao Morikawa, Masaru Nawaki
  • Patent number: 6822504
    Abstract: A correction circuit for generating a control signal for correcting a characteristic change of a first transistor includes a control signal adjusting section including a constant voltage reduction element for determining either one of a maximum voltage and a minimum voltage of the control signal and a second transistor for determining a characteristic of the control signal, a gate electrode of the second transistor receiving a prescribed voltage; and a resistor section including two types of resistor elements having resistance values of different temperature dependency characteristics from each other, the resistor elements being connected in series. The constant voltage reduction element, the second transistor, and the resistor section are connected in series between a supply terminal and a ground terminal. The control signal is output from a connection point between the control signal adjusting section and the resistor section.
    Type: Grant
    Filed: May 28, 2003
    Date of Patent: November 23, 2004
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Yoshinao Morikawa
  • Publication number: 20040228178
    Abstract: A semiconductor memory device has a malfunction prevention device and a nonvolatile memory.
    Type: Application
    Filed: May 10, 2004
    Publication date: November 18, 2004
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Koji Hamaguchi, Masaru Nawaki, Yoshinao Morikawa, Hiroshi Iwata, Akihide Shibata
  • Publication number: 20040228180
    Abstract: The present invention provides a method of programming, into a computer, a memory array having a plurality of memory cells, including a verification step 1 of verifying whether a memory cell has been already programmed or it has not been programmed yet per memory cell to be programmed, a flagging step 2 of flagging the memory cell in the case where it is verified that the memory cell has not been programmed yet in the several verifying steps, to which the memory cell is subjected thereafter, even if it is verified that the memory cell has been already programmed, a first application step 3 of applying a programming pulse having a programming level to the not-programmed memory cell without any flag, a repeat step 4 of repeating the verification step 1, the flagging step 2 and the first application step 3 until it is verified that all of the memory cells have been already programmed at least once, and a second application step 5 of applying a boost pulse having a boost programming level lower than that of the p
    Type: Application
    Filed: May 10, 2004
    Publication date: November 18, 2004
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Nobuaki Matsuoka, Masaru Nawaki, Yoshinao Morikawa, Hiroshi Iwata, Akihide Shibata
  • Publication number: 20040222456
    Abstract: A computer system comprising: (A) a CPU; (B) a memory arrangement comprising: (i) a side-wall memory array including a plurality of side-wall memory transistors; (ii) a charge pump; (iii) a plurality of switching circuits; and (iv) logic circuitry; and (C) a system bus, wherein each of the side-wall memory transistors comprises: a gate electrode formed on a semiconductor layer with a gate insulating film formed on the semiconductor layer; a channel region formed below the gate electrode; a pair of diffusion regions formed on the both sides of the channel region and having a conductive type opposite to that of the channel region; and a pair of memory functional units formed on the both sides of the gate electrode and having a function of retaining charges.
    Type: Application
    Filed: May 5, 2004
    Publication date: November 11, 2004
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Koji Hamaguchi, Masaru Nawaki, Yoshinao Morikawa, Hiroshi Iwata, Akihide Shibata
  • Publication number: 20040223372
    Abstract: A semiconductor memory device of the present invention includes an electrically programmable and erasable nonvolatile memory device which uses a plurality of memory cells requiring a first potential for reading data and a second potential for data programming, the second potential being higher than the first potential, a latch circuit for receiving data and temporarily storing the data, a pulse generator which generates a pulse used for programming data into a memory cell and is coupled in order to receive the second potential, a comparator for comparing data in the latch circuit with data in a memory cell, and a controller for controlling the pulse generator to repeatedly generate a pulse until the data in the latch circuit matches the data in the memory cell, the controller coupled to the comparator and the pulse generator. The controller controls so that the pulse is repeatedly generated until data is programmed in a memory cell.
    Type: Application
    Filed: May 6, 2004
    Publication date: November 11, 2004
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Nobuaki Matsuoka, Masaru Nawaki, Yoshinao Morikawa, Hiroshi Iwata, Akihide Shibata
  • Publication number: 20040222452
    Abstract: A method for driving a semiconductor memory device includes a memory array having a plurality of memory cells arranged in rows and columns. Each memory cell includes a gate electrode formed on a semiconductor layer via a gate insulating film, a channel region disposed below the gate electrode, a source and a drain as diffusion regions disposed on both sides of the channel region and having a conductive type opposite to that of the channel region, and memory functional units formed on both sides of the gate electrode and having a function of retaining charges. The method includes the steps of: selecting a row line connected to the gate electrode of a memory cell to be selected; grounding a first column line connected to the source of the memory cell to be selected; and applying a first potential to a second column line and a second potential to a third column line at the same time.
    Type: Application
    Filed: April 30, 2004
    Publication date: November 11, 2004
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Nobuaki Matsuoka, Masaru Nawaki, Yoshinao Morikawa, Hiroshi Iwata, Akihide Shibata, Kohji Hamaguchi
  • Publication number: 20040184318
    Abstract: The present invention prevents a reading operation margin from being decreased due to a current injected into a selected bit line after passing through an unselected bit line in a memory cell array configuration using virtual ground lines. A memory cell array is constituted by being divided into at least subarrays of a plurality of columns and memory cell columns at the both ends of the subarrays are constituted so that second electrodes are not connected each other but they are separated from each other between two memory cells adjacent to each other in the row direction at the both sides of boundaries between the subarrays and respectively connected to an independent bit line or virtual ground line, and one of word lines, one of bit lines, and one of virtual ground lines are selected and one memory cell from which data will be read is selected.
    Type: Application
    Filed: January 30, 2004
    Publication date: September 23, 2004
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Yoshinao Morikawa
  • Publication number: 20040160828
    Abstract: A semiconductor memory device including: a memory cell having a gate electrode formed on a semiconductor layer via a gate insulating film, a channel region disposed below the gate electrode, a diffusion region disposed on both sides of the channel region and having a conductive type opposite to that of the channel region, and memory functional units formed on both sides of the gate electrode and having a function of retaining charges; and an amplifier, the memory cell and the amplifier being connected to each other so that an output of the memory cell is inputted to the amplifier.
    Type: Application
    Filed: February 11, 2004
    Publication date: August 19, 2004
    Inventors: Hiroshi Iwata, Akihide Shibata, Yoshifumi Yaoi, Yasuaki Iwase, Masaru Nawaki, Yoshinao Morikawa, Kenichi Tanaka
  • Publication number: 20040130939
    Abstract: A memory cell array is included which is constituted by arranging the plurality of nonvolatile memory cells in a row direction and column direction respectively and arranging the plurality of word lines (WL) and the plurality of bit lines (BL) in the row direction and the column direction respectively in order to select a predetermined memory cell or a memory cell group out of the arranged nonvolatile memory cells, in which the memory cells are respectively constituted by connecting one end of a variable resistive element for storing information in accordance with a change of electrical resistances with the source of a selection transistor while in the memory cell array, the drain of the selection transistor is connected with a common bit line (BL) along the column direction, the other end of the variable resistive element is connected with a source line (SL), and the gate of the selection transistor is connected with the common word line (WL) along the row direction.
    Type: Application
    Filed: December 5, 2003
    Publication date: July 8, 2004
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Yoshinao Morikawa
  • Publication number: 20040114428
    Abstract: It is an object of the present invention to make it possible to decrease the on-state resistance of a selection transistor of a memory cell without increasing the whole area of a memory cell array and accelerate and stabilize the reading operation of data stored in the memory cell. Therefore, a plurality of variable resistive elements capable of storing information in accordance with a change of electrical resistances is included, one ends of the variable resistive elements are connected each other, and an electrode of a selection element constituted by a MOSFET or diode element for selecting the variable resistive elements in common is connected with one end of each of the variable resistive elements to constitute a memory cell.
    Type: Application
    Filed: December 5, 2003
    Publication date: June 17, 2004
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Yoshinao Morikawa
  • Patent number: 6710638
    Abstract: A voltage conversion circuit for converting the voltage of an input signal to the voltage of an output signal is provided. The circuit comprises a logic circuit for outputting an operation signal obtained by inverting and delaying the input signal based on a stand-by/operation control signal and an inverted signal having a polarity inverse to the stand-by/operation control signal or a stand-by signal obtained by delaying the input signal relative to the inverted signal based on the inverted signal, and a voltage output circuit for starting generating the output signal based on the input signal and the inverted signal before receiving the operation signal or the stand-by signal output by the logic circuit.
    Type: Grant
    Filed: May 28, 2003
    Date of Patent: March 23, 2004
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Yoshinao Morikawa
  • Patent number: 6707725
    Abstract: A reference voltage generation circuit includes at least one reference cell having a source electrode and a drain electrode; a plurality of first sense circuits connected to the reference cell and including an N-channel transistor, a P-channel transistor, a plurality of input ends and a plurality of output ends; and a plurality of second sense circuits each for receiving an output from a corresponding one of the plurality of first sense circuits, the plurality of second sense circuits each having a load circuit, an N-channel transistor, a plurality of input ends and a plurality of output ends.
    Type: Grant
    Filed: February 28, 2002
    Date of Patent: March 16, 2004
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Yoshinao Morikawa
  • Publication number: 20040027904
    Abstract: A reading circuit for reading information stored in a memory cell includes a current supply circuit for supplying a current to a bit line connected to the memory cell; a comparison circuit for comparing a potential of the bit line supplied with the current by the current supply circuit with a reference potential so as to output the information stored in the memory cell; a disconnection circuit for electrically disconnecting the comparison circuit and the memory cell from each other under a prescribed condition; a charge circuit for charging the bit line, the charge circuit stopping charging of the bit line when the potential of the bit line exceeds a prescribed potential; and a discharge circuit for discharging the bit line when the potential of the bit line exceeds the prescribed potential.
    Type: Application
    Filed: August 6, 2003
    Publication date: February 12, 2004
    Inventor: Yoshinao Morikawa
  • Publication number: 20030222679
    Abstract: A voltage conversion circuit for converting the voltage of an input signal to the voltage of an output signal is provided. The circuit comprises a logic circuit for outputting an operation signal obtained by inverting and delaying the input signal based on a stand-by/operation control signal and an inverted signal having a polarity inverse to the stand-by/operation control signal or a stand-by signal obtained by delaying the input signal relative to the inverted signal based on the inverted signal, and a voltage output circuit for starting generating the output signal based on the input signal and the inverted signal before receiving the operation signal or the stand-by signal output by the logic circuit.
    Type: Application
    Filed: May 28, 2003
    Publication date: December 4, 2003
    Inventor: Yoshinao Morikawa
  • Publication number: 20030222692
    Abstract: A correction circuit for generating a control signal for correcting a characteristic change of a first transistor includes a control signal adjusting section including a constant voltage reduction element for determining either one of a maximum voltage and a minimum voltage of the control signal and a second transistor for determining a characteristic of the control signal, a gate electrode of the second transistor receiving a prescribed voltage; and a resistor section including two types of resistor elements having resistance values of different temperature dependency characteristics from each other, the resistor elements being connected in series. The constant voltage reduction element, the second transistor, and the resistor section are connected in series between a supply terminal and a ground terminal. The control signal is output from a connection point between the control signal adjusting section and the resistor section.
    Type: Application
    Filed: May 28, 2003
    Publication date: December 4, 2003
    Inventor: Yoshinao Morikawa
  • Patent number: 6559514
    Abstract: A semiconductor memory device includes a semiconductor substrate; a plurality of word lines provided on the semiconductor substrate and arranged in parallel to each other; a plurality of memory cells provided along each of the plurality of word lines; a plurality of sub bit lines provided on the semiconductor substrate and arranged in parallel to each other, each of the plurality of word line intersecting the plurality of sub bit lines; a plurality of main bit lines arranged in parallel to the plurality of sub bit lines; a plurality of bank select lines arranged in parallel to the plurality of word lines; a plurality of bank select transistors provided along each of the plurality of bank select lines and connected to the respective sub bit lines; and a plurality of auxiliary conduction regions provided for each of the plurality of the main bit lines, connecting each of the plurality of the main bit lines to a set of the plurality of bank select transistors of the plurality of sub bit lines.
    Type: Grant
    Filed: April 13, 2000
    Date of Patent: May 6, 2003
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Yoshinao Morikawa
  • Patent number: 6535214
    Abstract: A semiconductor device for display control includes an input section for receiving a display information including a character code, a display position information and a character size information, a first address generating section for generating a first address group corresponding to the received character code by applying a predetermined conversion rule to the received character code and character size information, a font data storing section for outputting the font data stored in the region specified by the first address group when the first address group is given, a second address generating section for generating a second address group by utilizing the received display position information, the second address group representing a region where the font data is to be expanded, a font data expanding section for expanding and temporarily storing the font data in the region represented by the second address group, and an output section for outputting the font data to an external display driving unit.
    Type: Grant
    Filed: March 23, 2000
    Date of Patent: March 18, 2003
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshinao Morikawa, Junichi Tanimoto