Patents by Inventor Wataru Ichihara

Wataru Ichihara 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: 20070189137
    Abstract: Embodiments in accordance with the present invention provide methods to record, in a rotating disk storage device, a data block in the unit of a logical sector on a recording medium on which a physical sector including a plurality of logical sectors is formatted. Extra addresses are acquired in a buffer to record write data blocks transferred from a host device. Data blocks are read from the recording medium in the unit of a physical sector. A skip read section discards data blocks having the same data blocks as the write data blocks by removing them from the read data blocks, and sends the remaining data blocks to the buffer. The buffer stores the data blocks in the order of recording in a physical sector.
    Type: Application
    Filed: January 10, 2007
    Publication date: August 16, 2007
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Takahiro Saito, Takayuki Yamaguchi, Atsushi Kanamaru, Wataru Ichihara
  • Patent number: 6246653
    Abstract: A method and apparatus for reducing the effect of inter-wave interference on signals read from a storage medium and to precisely digitize the read signals are described. An apparatus for digitizing a signal read from a storage medium according to an embodiment of the invention, comprises: a peak detector, for detecting a peak value for an amplitude of a signal read from the storage medium; a threshold value determiner, for employing the peak value obtained by the peak detector to determine a compensation value that is used for compensating for the effect of inter-wave interference on the signal, and for employing the threshold value calculated by the conventional method and the compensation value to determine a compensated threshold value; and a digitization circuit, for digitizing the signal by using the threshold value determined by the threshold value determiner. Optionally an interpolator may be used to obtain more accurate peak values which occur between sample points.
    Type: Grant
    Filed: December 11, 1998
    Date of Patent: June 12, 2001
    Assignee: International Business Machines Corporation
    Inventors: Toshio Kanai, Takeo Yasuda, Kazuhiro Tsuruta, Wataru Ichihara