Patents by Inventor Tomotaro DOI

Tomotaro DOI 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).

  • Storage system with cells changeable between two different level cell modes based on predicted lifetime
    Patent number: 10387062
    Abstract: A storage system according to one aspect of the present invention includes a plurality of storage devices using flash memory as a storage medium. The flash memory used for the storage device may include flash memory configured to operate each cell as a cell capable of storing n-bit information or a cell capable of storing m-bit information (where n<m), where n=2 and m=3. The storage system may periodically acquire a number of remaining erasures from the storage device and predict the lifetime of the storage device by using the acquired number of remaining erasures and the storage device operation time. If the predicted lifetime is greater than a predetermined value (service life), a predetermined number of cells may be changed to cells capable of storing m-bit information.
    Type: Grant
    Filed: November 27, 2015
    Date of Patent: August 20, 2019
    Assignee: HITACHI, LTD.
    Inventors: Tomotaro Doi, Shigeo Homma, Kenta Ninose
  • STORAGE SYSTEM
    Publication number: 20180203631
    Abstract: A storage system according to one aspect of the present invention includes a plurality of storage devices using flash memory as a storage medium. The flash memory used for the storage device may include flash memory configured to operate each cell as a cell capable of storing n-bit information or a cell capable of storing m-bit information (where n<m). The storage system may periodically acquire a number of remaining erasures form the storage device and predict the lifetime of the storage device by using the acquired number of remaining erasures and the storage device operation time. If the predicted lifetime is greater than a predetermined value (service life) a predetermined number of cells may be changed to cells capable of storing m-bit information.
    Type: Application
    Filed: November 27, 2015
    Publication date: July 19, 2018
    Applicant: HITACHI, LTD.
    Inventors: Tomotaro DOI, Shigeo HOMMA, Kenta NINOSE