Patents by Inventor Ikuo Saitoh

Ikuo Saitoh 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: 6728051
    Abstract: A recording equalizer for correcting a write timing of magnetic information when the magnetic information is recorded with a magnetic recording head on a magnetic recording medium, includes a buffer for storing a recording object bit and bits before and after the recording object bit and a calculator for calculating a precompensation parameter using the bits stored in the buffer. The calculator calculates the preconpensation parameter of the recording object bit by linearly adding influence of a transition existing at a two-previous bit of the recording object bit, influences of a transition at a one-previous bit of the recording object bit and influences of a transition existing at one-following bit of the recording object bit and further adding an offset. The offset is determined to a value such that a write timing of the magnetic information is corrected always in a delaying direction.
    Type: Grant
    Filed: March 17, 2003
    Date of Patent: April 27, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Masukazu Igarashi, Yohji Maruyama, Kazuetsu Yoshida, Ikuo Saitoh
  • Publication number: 20030142430
    Abstract: A recording equalizer for correcting a write timing of magnetic information when the magnetic information is recorded with a magnetic recording head on a magnetic recording medium, includes a buffer for storing a recording object bit and bits before and after the recording object bit and a calculator for calculating a precompensation parameter using the bits stored in the buffer. The calculator calculates the preconpensation parameter of the recording object bit by linearly adding influence of a transition existing at a two-previous bit of the recording object bit, influences of a transition at a one-previous bit of the recording object bit and influences of a transition existing at one-following bit of the recording object bit and further adding an offset. The offset is determined to a value such that a write timing of the magnetic information is corrected always in a delaying direction.
    Type: Application
    Filed: March 17, 2003
    Publication date: July 31, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Masukazu Igarashi, Yohji Maruyama, Kazuetsu Yoshida, Ikuo Saitoh
  • Patent number: 6549355
    Abstract: A recording equalizer for correcting a write timing of magnetic information when the magnetic information is recorded with a magnetic recording head on a magnetic recording medium, includes a buffer for storing a recording object bit and bits before and after the recording object bit and a calculator for calculating a precompensation parameter using the bits stored in the buffer. The calculator calculates the precompensation parameter of the recording object bit by linearly adding influence of a transition existing at a two-previous bit of the recording object bit, influences of a transition at a one-previous bit of the recording object bit and influences of a transition existing at one-following bit of the recording object bit and further adding an offset. The offset is determined to a value such that a write timing of the magnetic information is corrected always in a delaying direction.
    Type: Grant
    Filed: August 30, 2002
    Date of Patent: April 15, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Masukazu Igarashi, Yohji Maruyama, Kazuetsu Yoshida, Ikuo Saitoh
  • Publication number: 20030026024
    Abstract: A recording equalizer for correcting a write timing of magnetic information when the magnetic information is recorded with a magnetic recording head on a magnetic recording medium, includes a buffer for storing a recording object bit and bits before and after the recording object bit and a calculator for calculating a precompensation parameter using the bits stored in the buffer. The calculator calculates the preconpensation parameter of the recording object bit by linearly adding influence of a transition existing at a two-previous bit of the recording object bit, influences of a transition at a one-previous bit of the recording object bit and influences of a transition existing at one-following bit of the recording object bit and further adding an offset. The offset is determined to a value such that a write timing of the magnetic information is corrected always in a delaying direction.
    Type: Application
    Filed: August 30, 2002
    Publication date: February 6, 2003
    Inventors: Masukazu Igarashi, Yohji Maruyama, Kazuetsu Yoshida, Ikuo Saitoh
  • Patent number: 6487031
    Abstract: A recording equalizer for correcting a write timing of magnetic information when the magnetic information is recorded with a magnetic recording head on a magnetic recording medium, includes a buffer for storing a recording object bit and bits before and after the recording object bit and a calculator for calculating a precompensation parameter using the bits stored in the buffer. The calculator calculates the preconpensation parameter of the recording object bit by linearly adding influence of a transition existing at a two-previous bit of the recording object bit, influences of a transition at a one-previous bit of the recording object bit and influences of a transition existing at one-following bit of the recording object bit and further adding an offset. The offset is determined to a value such that a write timing of the magnetic information is corrected always in a delaying direction.
    Type: Grant
    Filed: February 22, 2002
    Date of Patent: November 26, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Masukazu Igarashi, Yohji Maruyama, Kazuetsu Yoshida, Ikuo Saitoh
  • Publication number: 20020114093
    Abstract: A recording equalizer for correcting a write timing of magnetic information when the magnetic information is recorded with a magnetic recording head on a magnetic recording medium, includes a buffer for storing a recording object bit and bits before and after the recording object bit and a calculator for calculating a precompensation parameter using the bits stored in the buffer. The calculator calculates the preconpensation parameter of the recording object bit by linearly adding influence of a transition existing at a two-previous bit of the recording object bit, influences of a transition at a one-previous bit of the recording object bit and influences of a transition existing at one-following bit of the recording object bit and further adding an offset. The offset is determined to a value such that a write timing of the magnetic information is corrected always in a delaying direction.
    Type: Application
    Filed: February 22, 2002
    Publication date: August 22, 2002
    Inventors: Masukazu Igarashi, Yohji Maruyama, Kazuetsu Yoshida, Ikuo Saitoh
  • Patent number: 6356402
    Abstract: A recording equalizer for correcting a write timing of magnetic information when the magnetic information is recorded with a magnetic recording head on a magnetic recording medium, includes a buffer for storing a recording object bit and bits before and after the recording object bit and a calculator for calculating a precompensation parameter using the bits stored in the buffer. The calculator calculates the preconpensation parameter of the recording object bit by linearly adding influence of a transition existing at a two-previous bit of the recording object bit, influences of a transition at a one-previous bit of the recording object bit and influences of a transition existing at one-following bit of the recording object bit and further adding an offset. The offset is determined to a value such that a write timing of the magnetic information is corrected always in a delaying direction.
    Type: Grant
    Filed: February 23, 2001
    Date of Patent: March 12, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Masukazu Igarashi, Yohji Maruyama, Kazuetsu Yoshida, Ikuo Saitoh
  • Publication number: 20010007516
    Abstract: A recording equalizer for correcting a write timing of magnetic information when the magnetic information is recorded with a magnetic recording head on a magnetic recording medium, includes a buffer for storing a recording object bit and bits before and after the recording object bit and a calculator for calculating a precompensation parameter using the bits stored in the buffer. The calculator calculates the preconpensation parameter of the recording object bit by linearly adding influence of a transition existing at a two-previous bit of the recording object bit, influences of a transition at a one-previous bit of the recording object bit and influences of a transition existing at one-following bit of the recording object bit and further adding an offset. The offset is determined to a value such that a write timing of the magnetic information is corrected always in a delaying direction.
    Type: Application
    Filed: February 23, 2001
    Publication date: July 12, 2001
    Inventors: Masukazu Igarashi, Yohji Maruyama, Kazuetsu Yoshida, Ikuo Saitoh
  • Patent number: 6212024
    Abstract: A recording equalizer for precompensating of a write timing of magnetic information when the magnetic information is recorded by a magnetic recording head on a magnetic recording medium, includes a buffer for storing a recording object bit and bits before and after said recording object bit, and a calculator for calculating and outputting a precompensation parameter using the bits stored in the buffer by adding an offset C, having a value such as to always delay the write timing of the magnetic information, to an amount of shift determined using the bits stored in the buffer and the head velocity relative to the medium.
    Type: Grant
    Filed: May 28, 1998
    Date of Patent: April 3, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Masukazu Igarashi, Yohji Maruyama, Kazuetsu Yoshida, Ikuo Saitoh