Patents by Inventor Kinya Ashikaga

Kinya Ashikaga 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: 6496407
    Abstract: A ferroelectric memory of the present invention comprises a memory cell which includes a select transistor whose control electrode, first electrode and second electrode are respectively connected to a word line, a bit line and a first node, a ferroelectric capacitor whose first electrode and second electrode are respectively connected to the first node and connected to a plate line through a second node, and a resistor connected between the first node and the second node.
    Type: Grant
    Filed: December 21, 2000
    Date of Patent: December 17, 2002
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Kinya Ashikaga
  • Publication number: 20020176274
    Abstract: The object of the present invention is to provide a ferroelectric memory device in which an imprint is prevented, and a method of operating a ferroelectric memory device for preventing the characteristics from deteriorating due to an imprint.
    Type: Application
    Filed: May 23, 2002
    Publication date: November 28, 2002
    Applicant: Oki Electric Industry Co., Ltd.
    Inventor: Kinya Ashikaga
  • Publication number: 20020131292
    Abstract: A ferroelectric memory of a 1T/1C type has a pair of dummy memory cells DMC2n−1 and DMC2n. Different information have been stored in the dummy memory cells. When the information is read out from each dummy memory cell, a potential Va is developed on a bit line BL2n−1, a potential Vb is developed on an adjacent bit line BL2n. Since the bit lines BL2n−1 and BL2n have the same capacitance, a potential Vave of each bit line which was short-circuited by a short-circuit portion s2a is equal to a just intermediate value (Va+Vb)/2 of the potentials Va and Vb. The potential Vave is applied to sense amplifiers SAn−1 and SAn as a reference potential.
    Type: Application
    Filed: August 31, 2001
    Publication date: September 19, 2002
    Inventor: Kinya Ashikaga
  • Patent number: 6411540
    Abstract: A ferroelectric memory device in which an imprint is prevented, and a method of operating the ferroelectric memory device to prevent its characteristics from deteriorating due to an imprint. The ferroelectric memory device includes a sense amplifier having first and second transistors which connect first and third sub-bit lines to a ground in accordance with a sense amplifier control signal, third and fourth transistors which connect the first sub-bit line with a fourth sub-bit line and further connect the third sub-bit line with a second sub-bit line in accordance with a first switching control signal, and fifth and sixth transistors which connect the first sub-bit line with the second sub-bit line and further connect the third sub-bit line with the fourth sub-bit line in accordance with a second switching control signal.
    Type: Grant
    Filed: August 23, 2000
    Date of Patent: June 25, 2002
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Kinya Ashikaga
  • Publication number: 20020036915
    Abstract: A ferroelectric memory of the present invention comprises a memory cell which includes a select transistor whose control electrode, first electrode and second electrode are respectively connected to a word line, a bit line and a first node, a ferroelectric capacitor whose first electrode and second electrode are respectively connected to the first node and connected to a plate line through a second node, and a resistor connected between the first node and the second node.
    Type: Application
    Filed: December 21, 2000
    Publication date: March 28, 2002
    Inventor: Kinya Ashikaga
  • Patent number: 6198654
    Abstract: Since the ferroelectric memory device is a 1T1C type, the size of one memory cell can be smaller than that of a 2T2C type. In this ferroelectric memory device, the reference potential does not have to be generated when data is read.
    Type: Grant
    Filed: June 19, 2000
    Date of Patent: March 6, 2001
    Assignee: Oki Electric Industry, Co., Ltd.
    Inventor: Kinya Ashikaga