Patents by Inventor Yoshikazu Soeno

Yoshikazu Soeno 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: 20090207522
    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: April 30, 2009
    Publication date: August 20, 2009
    Applicant: TDK CORPORATION
    Inventors: Akimasa KAIZU, Yoshikazu SOENO, Makoto MORIYA
  • Publication number: 20090185308
    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: March 27, 2009
    Publication date: July 23, 2009
    Applicant: TDK CORPORATION
    Inventors: Akimasa KAIZU, Yoshikazu SOENO, Makoto MORIYA
  • Publication number: 20090168245
    Abstract: Data track patterns and servo patterns are formed on an information recording medium by concave/convex patterns divided into ring-shaped regions that are concentric with the data track patterns. In the servo patterns, a unit convex length and a unit concave length along the direction of rotation increase in each ring-shaped region from an inside to an outside of the ring-shaped region in proportion to the distance from the center of the data track patterns and a value produced by dividing an average unit convex (or concave) length inside each ring-shaped region by a distance from the center to the ring-shaped region decreases toward the outer periphery of the medium. The ring-shaped regions include plural first regions between an innermost region and an outermost region. Respective lengths along a radial direction of the first regions increase toward an outer periphery of the medium.
    Type: Application
    Filed: December 23, 2008
    Publication date: July 2, 2009
    Applicant: TDK CORPORATION
    Inventors: Yoshikazu Soeno, Kazuya Shimakawa
  • Patent number: 7554768
    Abstract: On an information recording medium, a data track pattern and a servo pattern composed of a concave/convex pattern including a plurality of convex parts are formed on at least one surface of a substrate and respective concave parts in the concave/convex pattern are filled with non-magnetic material. In the concave/convex pattern that constructs the data track pattern, the respective convex parts are formed concentrically or in a spiral. In the concave/convex pattern that constructs the servo pattern, a unit convex part length along a direction of rotation of the substrate is set so that a value produced by dividing the unit convex part length by a distance from a center of the data track pattern decreases from an inner periphery to an outer periphery.
    Type: Grant
    Filed: August 31, 2005
    Date of Patent: June 30, 2009
    Assignee: TDK Corporation
    Inventors: Yoshikazu Soeno, Takahiro Suwa
  • Patent number: 7548388
    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: Grant
    Filed: February 15, 2006
    Date of Patent: June 16, 2009
    Assignee: TDK Corporation
    Inventors: Akimasa Kaizu, Yoshikazu Soeno, Makoto Moriya
  • Patent number: 7532423
    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: Grant
    Filed: February 15, 2006
    Date of Patent: May 12, 2009
    Assignee: TDK Corporation
    Inventors: Akimasa Kaizu, Yoshikazu Soeno, Makoto Moriya
  • Patent number: 7505220
    Abstract: On a magnetic recording medium, a servo pattern is formed in a servo pattern region on at least one surface of a substrate by a concave/convex pattern including a convex part, at least protruding end part of which is formed of magnetic material, and a concave part. The servo pattern region includes an address pattern region and a burst pattern region, wherein the convex part is formed in the servo pattern region so that a larger of an inscribed circle with a largest diameter out of inscribed circles on an open surface of the concave part formed in the address pattern region and an inscribed circle with a largest diameter out of inscribed circles on an open surface of the concave part formed in the burst pattern region is an inscribed circle with a largest diameter out of inscribed circles on an open surface of the concave part formed in the servo pattern region.
    Type: Grant
    Filed: February 22, 2006
    Date of Patent: March 17, 2009
    Assignee: TDK Corporation
    Inventors: Yoshikazu Soeno, Kazuya Shimakawa
  • Publication number: 20090059409
    Abstract: The magnetic recording and reproducing apparatus includes: a perpendicular recording magnetic recording medium including a track pattern including track portions and gap portions arranged so as to be alternately adjacent to each other in a cross-track direction, at least part of portions corresponding to the track portions being recording areas having the width substantially the same as the width of the track portions, portions between the recording areas being non-recording areas; and a magnetic head of a perpendicular recording type for applying a recording magnetic field to the recording areas. The anisotropic magnetic field Hk (T) of the recording areas of the magnetic recording medium and the recording magnetic field intensity Fw (t) of the recording magnetic field at the upper surface of the recording areas satisfy the following inequality (I): 0.23×Fw+1.2?Hk?0.26×Fw+1.6.
    Type: Application
    Filed: August 27, 2008
    Publication date: March 5, 2009
    Applicant: TDK CORPORATION
    Inventors: Akimasa Kaizu, Yoshikazu Soeno, Katsumichi Tagami
  • Publication number: 20090034115
    Abstract: A servo pattern is formed in a servo pattern region on at least one surface of a substrate of a magnetic recording medium by a concave/convex pattern including a plurality of convex parts, at least protruding end parts of which are formed of magnetic material, and at least one concave part. The servo pattern region includes an address pattern region and a burst pattern region. The at least one concave part is formed in the servo pattern region so that a larger of an inscribed circle with a largest diameter out of inscribed circles on protruding end surfaces of the convex parts formed in the address pattern region and an inscribed circle with a largest diameter out of inscribed circles on protruding end surfaces of the convex parts formed in the burst pattern region is an inscribed circle with a largest diameter out of inscribed circles on protruding end surfaces of the convex parts formed in the servo pattern region.
    Type: Application
    Filed: October 10, 2008
    Publication date: February 5, 2009
    Applicant: TDK Corporation
    Inventors: Yoshikazu SOENO, Takahiro SUWA
  • Patent number: 7482070
    Abstract: A magnetic recording medium having high reliability is provided, in which concave portions between recording elements formed as convex portions of a concavo-convex pattern are approximately completely filled with a non-magnetic material. The magnetic recording medium is a plate-like body including: a substrate; a recording layer that is formed in a predetermined concavo-convex pattern over the substrate and includes recording elements for recording information formed as convex portions of the concavo-convex pattern; and the non-magnetic material filling concave portions between the recording elements. Side faces of the recording elements are inclined to face a surface of the plate-like body on a side toward which the recording elements 16 project in the concavo-convex pattern. An inclination angle of the side faces of the recording elements with respect to a direction perpendicular to that surface is smaller than 90° and 5° or more.
    Type: Grant
    Filed: April 27, 2005
    Date of Patent: January 27, 2009
    Assignee: TDK Corporation
    Inventors: Mitsuru Takai, Yoshikazu Soeno, Katsumichi Tagami, Kazuya Shimakawa
  • Patent number: 7480924
    Abstract: A magnetic recording and reproducing device includes: a magnetic recording medium in which a magnetic recording layer is formed in a concavo-convex pattern so that tracks are formed by convex portions of a predetermined track width and arranged in parallel in the track width direction; a heating head for heating the magnetic recording medium to partially reduce coercivity of the tracks; a recording head for applying a recording magnetic field to a heated portion of the magnetic recording medium to record magnetic data on the tracks; and a reproducing head for detecting a reproducing magnetic field of the tracks. In this configuration, an effective recording area has an effective recording width that is equal to or more than the track width, and equal to or less than a sum of the track width and a doubled value of width of concave portions between the tracks.
    Type: Grant
    Filed: February 14, 2005
    Date of Patent: January 20, 2009
    Assignee: TDK Corporation
    Inventors: Kazuhiro Hattori, Yoshikazu Soeno, Mitsuru Takai, Shuichi Okawa
  • Patent number: 7477485
    Abstract: On an information recording medium, a data track pattern and a servo pattern composed of a concave/convex pattern including a plurality of convex parts are formed on at least one surface side of a substrate and respective concave parts in the concave/convex pattern are filled with non-magnetic material. The concave/convex pattern that constructs the servo pattern is divided into a plurality of ring-shaped regions that are concentric with the data track pattern and has a unit convex part length along a direction of rotation of the substrate set in each ring-shaped region so that a value produced by dividing an average length of the unit convex part length in each ring-shaped region by a distance from a center of the data track pattern to the ring-shaped region decreases from ring-shaped regions in an inner periphery to ring-shaped regions in an outer periphery.
    Type: Grant
    Filed: September 20, 2005
    Date of Patent: January 13, 2009
    Assignee: TDK Corporation
    Inventors: Yoshikazu Soeno, Takahiro Suwa
  • Patent number: 7474506
    Abstract: In a magnetic recording medium including a servo pattern region having a servo pattern formed of a concave/convex pattern having convex portions and concave portions and a data recording region, the region having a data track pattern, the concave portions are formed in an address pattern region of the servo pattern region such that the maximum lengths, which are located in the respective same radius regions of the respective lengths along the rotating direction of a substrate of the projecting end surfaces of the convex portions constituting the concave/convex pattern are set to first lengths that are double the minimum lengths along the rotating direction of the projecting end surfaces of the convex portions in the respective same radius regions. With this arrangement, the magnetic recording medium can securely read a magnetic signal and has a servo pattern having excellent surface smoothness.
    Type: Grant
    Filed: November 3, 2005
    Date of Patent: January 6, 2009
    Assignee: TDK Corporation
    Inventors: Yoshikazu Soeno, Takahiro Suwa
  • Patent number: 7457082
    Abstract: A magnetic recording medium constructed as a discrete track-type medium. The magnetic recording medium is constructed so that a track width of data recording tracks is equal to or smaller than a width produced by subtracting twice an off-track width of a magnetic head with respect to the data recording tracks during a recording of the recording data from a magnetic effective recording head width of the magnetic head. The track width is equal to or smaller than a width produced by subtracting twice an off-track width of the magnetic head with respect to the data recording tracks during a reproduction of the recording data from a magnetic effective reproduction head width of the magnetic head.
    Type: Grant
    Filed: March 16, 2007
    Date of Patent: November 25, 2008
    Assignee: TDK Corporation
    Inventor: Yoshikazu Soeno
  • Patent number: 7443622
    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: Grant
    Filed: August 30, 2005
    Date of Patent: October 28, 2008
    Assignee: TDK Corporation
    Inventors: Akimasa Kaizu, Makoto Moriya, Yoshikazu Soeno
  • Patent number: 7403355
    Abstract: On an information recording medium, a data track pattern and a servo pattern composed of a concave/convex pattern including a plurality of convex parts are formed on at least one surface of a substrate and respective concave parts in the concave/convex pattern are filled with non-magnetic material. In the concave/convex pattern that constructs the servo pattern, a unit convex part length along a direction of rotation of the substrate and a unit concave part length along the direction of rotation are set so that the ratio of the unit convex part length to the unit concave part length decreases from an inner periphery to an outer periphery of the information recording medium.
    Type: Grant
    Filed: August 31, 2005
    Date of Patent: July 22, 2008
    Assignee: TDK Corporation
    Inventors: Yoshikazu Soeno, Takahiro Suwa
  • Publication number: 20080144230
    Abstract: A magnetic recording-reproducing apparatus includes: a magnetic recording medium in which portions corresponding to track portions serve as recording areas and in which portions between the recording areas serve as non-recording areas; and a magnetic head having a main pole and a side shield disposed on both sides of the main pole in a cross-track direction. In the magnetic recording-reproducing apparatus, following inequality (I) is satisfied: S>Tw/2+Gw ??(I) where Tw is a track width, Gw is a gap width, and S is a distance between the center of the main pole of the magnetic head and an edge on the main pole side of each of the side shields.
    Type: Application
    Filed: December 11, 2007
    Publication date: June 19, 2008
    Applicant: TDK CORPORATION
    Inventors: Akimasa Kaizu, Yoshikazu Soeno, Kazuya Shimakawa
  • Patent number: 7368184
    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: Grant
    Filed: September 24, 2004
    Date of Patent: May 6, 2008
    Assignee: TDK Corporation
    Inventors: Akimasa Kaizu, Yoshikazu Soeno
  • Patent number: 7333289
    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: Grant
    Filed: March 17, 2006
    Date of Patent: February 19, 2008
    Assignee: TDK Corporation
    Inventors: Akimasa Kaizu, Yoshikazu Soeno, Makoto Moriya
  • Patent number: 7307808
    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: Grant
    Filed: October 25, 2005
    Date of Patent: December 11, 2007
    Assignee: TDK Corporation
    Inventors: Akimasa Kaizu, Yoshikazu Soeno, Makoto Moriya