Patents by Inventor Akimasa Kaizu

Akimasa Kaizu 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: 20060215311
    Abstract: A magnetic recording and reproducing apparatus and a method of controlling the same, capable of increasing the output of a position control signal and performing a precise positioning control of a magnetic head. The magnetic recording and reproducing apparatus has: a magnetic recording medium on which a positional information is recorded in the form of burst signal groups each consisting of either one of a single concave portion and a single convex portion of a predetermined concavo-convex pattern formed of a magnetic layer; a gate circuit; and an integrator for calculating a area integral of a reproduced signal corresponding to each of the burst signal groups.
    Type: Application
    Filed: March 17, 2006
    Publication date: September 28, 2006
    Applicant: TDK Corporation
    Inventors: Akimasa Kaizu, Yoshikazu Soeno, Makoto Moriya
  • Publication number: 20060209454
    Abstract: A magnetic recording and reproducing apparatus has a magnetic recording medium onto which servo information including position information is recorded by a concavo-convex pattern formed by a magnetic layer and a signal processing circuit that generates position control signal of a magnetic head based on amplitude values of fundamental wave component and at least one harmonic component in a reproduced signal of the position information. This magnetic recording and reproducing apparatus can increase the output of the position control signal and also increase the accuracy of the positioning control of the magnetic head.
    Type: Application
    Filed: October 25, 2005
    Publication date: September 21, 2006
    Applicant: TDK CORPORATION
    Inventors: Akimasa Kaizu, Yoshikazu Soeno, Makoto Moriya
  • Publication number: 20060209453
    Abstract: A magnetic recording and reproducing apparatus includes: a magnetic recording medium onto which servo information including position information is recorded by a plurality of concavo-convex patterns formed by a magnetic layer; a gate circuit that extracts a part of a reproducing signal of the concavo-convex patterns by removing an end of a signal corresponding to a concave portion or a convex portion of the concavo-convex patterns from the reproducing signal; a first integrator that obtains area integral of an extracted reproducing signal; and a second integrator that adds respective signals after area integral is obtained to each other to generate a position control signal for controlling a position of a magnetic head. Thus, the magnetic recording and reproducing apparatus can make an output of the position control signal larger and can perform positioning control for the magnetic head with high precision.
    Type: Application
    Filed: August 30, 2005
    Publication date: September 21, 2006
    Applicant: TDK CORPORATION
    Inventors: Akimasa Kaizu, Yoshikazu Soeno, Makoto Moriya
  • Publication number: 20060203368
    Abstract: On a magnetic recording medium, M sets of burst patterns are formed along a direction of rotation of a substrate in each burst pattern region, where M is a natural number of two or higher. Each burst pattern is formed so as to include two types of burst signal units that are positioned at different distances from a center of data track patterns and have an equal length along a radial direction of the substrate. The length along the radial direction is (2·M/N) times the track pitch, where N is a natural number of two or higher.
    Type: Application
    Filed: February 15, 2006
    Publication date: September 14, 2006
    Applicant: TDK Corporation
    Inventors: Akimasa Kaizu, Yoshikazu Soeno, Makoto Moriya
  • Publication number: 20060198042
    Abstract: On a magnetic recording medium, M sets of burst patterns are formed along a direction of rotation of a substrate in each burst pattern region, where M is a natural number of two or higher. Each burst pattern is formed so as to include two types of burst signal units that are positioned at different distances from a center of data track patterns and have an equal length along a radial direction of the substrate. The length along the radial direction is (2·M/N) times the track pitch, where N is a natural number of two or higher.
    Type: Application
    Filed: May 15, 2006
    Publication date: September 7, 2006
    Applicant: TDK Corporation
    Inventors: Akimasa Kaizu, Yoshikazu Soeno, Makoto Moriya
  • Publication number: 20060050426
    Abstract: A reliable magnetic recording medium is provided which comprises a servo signal unit portions formed in a concavo-convex shape, easily produced, and resistant to tracking error. Also provided are a magnetic recording/reproducing apparatus which incorporates the magnetic recording medium, and a stamper for manufacturing the magnetic recording medium with efficiency. The magnetic recording medium includes a recording layer divided into a plurality of data areas and a plurality of servo areas to record information. The recording layer is formed in a concavo-convex shape in each servo area, with a servo signal unit portions formed as either a convex portions or a concave portions of the concavo-convex shape. Of the servo signal unit portions, the burst signal unit portion for tracking is generally elliptical in shape when viewed from the direction of thickness.
    Type: Application
    Filed: August 30, 2005
    Publication date: March 9, 2006
    Applicant: TDK CORPORATION
    Inventors: Akimasa Kaizu, Makoto Moriya, Yoshikazu Soeno
  • Publication number: 20060044660
    Abstract: A magnetic recording and reproducing apparatus includes a separator and first and second amplifiers. The separator separates a servo data signal and a user data signal, both reproduced by a reproducing head. The first and second amplifiers are connected to the output stage of the separator to increase the amplitude ratio of the servo data signal to the user data signal. The magnetic recording and reproducing apparatus can precisely decode the servo data along with the user data, and can achieve a highly precise servo control.
    Type: Application
    Filed: May 24, 2005
    Publication date: March 2, 2006
    Applicant: TDK CORPORATION
    Inventors: Akimasa Kaizu, Makoto Moriya
  • Publication number: 20060040140
    Abstract: A perpendicular recording type, magnetic recording medium having a soft magnetic layer and a magnetic recording/reproducing apparatus including such a magnetic recording medium are provided. The magnetic recording medium allows the recording magnetic field to be efficiently applied to a track for recording while restricting the extent of the recording magnetic field. The magnetic recording medium has a soft magnetic layer and a recording layer formed in this order on a substrate. The soft magnetic layer has its part on the opposite side to the substrate formed in a concavo-convex pattern. The recording layer is oriented to have magnetic anisotropy in the direction perpendicular to the surface. A fixing layer for fixing the magnetic anisotropy of the soft magnetic layer in a predetermined direction parallel to the surface is provided between the recording layer and the soft magnetic layer.
    Type: Application
    Filed: August 10, 2005
    Publication date: February 23, 2006
    Applicant: TDK CORPORATION
    Inventors: Akimasa Kaizu, Katsumichi Tagami, Kazuya Shimakawa
  • Publication number: 20050254157
    Abstract: The magnetic recording and reproducing device has a magnetic recording medium, a recording head for writing magnetic data on the magnetic recording medium, and a reproducing head for reading magnetic data from the magnetic recording medium. In the magnetic recording medium, each track is formed by a convex portion with a predetermined track width, and a plurality of the tracks are arranged in parallel at intervals of a predetermined track gap. The relationship represented by the following formula (I) is satisfied: {Tw+(2×Tg)}/1.2?MWw??(I) wherein Tw represents the track width, Tg represents the track gap, and MWw represents the magnetic write width of the recording head.
    Type: Application
    Filed: April 18, 2005
    Publication date: November 17, 2005
    Applicant: TDK Corporation
    Inventors: Akimasa Kaizu, Yoshikazu Soeno
  • Publication number: 20050095402
    Abstract: A magnetic recording medium which has a high areal density and reduced power consumption for recording operations, and a magnetic recording device incorporating the magnetic recording medium. The magnetic recording medium has an upper soft magnetic layer formed uniformly along a plane including the upper surface of a recording layer over the convex and concave portions of a concavo-convex pattern in the recording layer.
    Type: Application
    Filed: September 24, 2004
    Publication date: May 5, 2005
    Applicant: TDK CORPORATION
    Inventors: Akimasa Kaizu, Yoshikazu Soeno
  • Patent number: 6852404
    Abstract: The average major-axis length (L) of a ferromagnetic alloy powder primarily contained together with a binder in a magnetic layer provided on at least one surface of a non-magnetic support is less than 0.10 ?m, and the ferromagnetic alloy powder contains Co at a content of 15 to 28 at % relative to Fe, and furthermore, contains Y at a content of 22 ?mol/m2 or more with respect to a specific surface area (Sc) calculated from the above-mentioned average major-axis length (L) and the crystallite diameter (d). A coating-type high-recording-density magnetic recording medium has excellent surface properties, an excellent electromagnetic transducing characteristic especially in short wavelength regions and high reliability.
    Type: Grant
    Filed: March 27, 2003
    Date of Patent: February 8, 2005
    Assignee: TDK Corporation
    Inventors: Takayoshi Kuwajima, Osamu Inoue, Akimasa Kaizu
  • Publication number: 20040110033
    Abstract: The average major-axis length (L) of a ferromagnetic alloy powder primarily contained together with a binder in a magnetic layer provided on at least one surface of a magnetic support is less than 0.10 &mgr;m, and the ferromagnetic alloy powder contains Co at a content of 15 to 28 at % relative to Fe, and furthermore, contains Y at a content of 22 &mgr;mol/m2 or more with respect to a specific surface area (Sc) calculated from the above-mentioned average major-axis length (L) and the crystallite diameter (d). A coating-type high-recording-density magnetic recording medium has excellent surface properties, an excellent electromagnetic transducing characteristic especially in short wavelength regions and high reliability.
    Type: Application
    Filed: March 27, 2003
    Publication date: June 10, 2004
    Applicant: TDK CORPORATION
    Inventors: Takayoshi Kuwajima, Osamu Inoue, Akimasa Kaizu