Patents by Inventor Takayuki Kaida

Takayuki Kaida 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).

  • Non-volatile semiconductor memory device having long-life memory cells and data erasing method
    Patent number: 5923589
    Abstract: A non-volatile semiconductor memory device is provided that includes a split gate type memory cell and a control unit. The split gate type memory cell has a floating gate electrode and a control gate electrode. The control unit counts a number of data rewritings and controls the voltage applied to the control gate electrode so that the Fowler-Nordheim tunnel current increases to sufficiently pull out the charge stored in the floating gate electrode when the number of data writings exceeds a predetermined number. This extends the life of the memory device.
    Type: Grant
    Filed: October 30, 1997
    Date of Patent: July 13, 1999
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Takayuki Kaida, Yukihiro Ohya