Patents by Inventor Mitsuru Otagiri

Mitsuru Otagiri 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: 20090097159
    Abstract: A manufacturing method for a perpendicular magnetic recording head includes the steps of forming a groove in a first nonmagnetic layer, forming a side shield, forming a second nonmagnetic layer, forming a main-magnetic-pole front end portion and forming a main-magnetic-pole yoke portion. The groove extends in a front-rear direction orthogonal to an air bearing surface. The side shield of soft magnetic material, the second nonmagnetic layer and the main-magnetic-pole front end portion of soft magnetic material are formed on an inner wall of the groove. The main-magnetic-pole front end portion is not magnetostatically coupled to the side shield. The main-magnetic-pole yoke portion magnetically is insulated from the side shield and magnetically connected to the main-magnetic-pole front end portion. The main-magnetic-pole yoke portion widens from the main-magnetic-pole front end portion toward a rear side.
    Type: Application
    Filed: September 23, 2008
    Publication date: April 16, 2009
    Applicant: FUJITSU LIMITED
    Inventors: Mitsuru Otagiri, Hiroshi Shirataki, Yuko Miyake
  • Publication number: 20080291571
    Abstract: A magnetic head of the present invention includes a magnetic pole that faces a surface of a recording medium, moves relative to the surface in a direction along the surface, and produces a line of magnetic force intersecting the surface of the recording medium; and a coil that excites the magnetic pole, wherein the magnetic pole includes a laminate with a coercivity of 800 A/m or less, the laminate including two or more layers stacked in a direction along the movement relative to the surface of the recording medium, the two or more layers including a first magnetic layer located at a frontmost position of the movement, and a second magnetic layer located at a rearmost position of the movement, the second magnetic layer having a saturation magnetic flux density higher than a saturation magnetic flux density of the first magnetic layer.
    Type: Application
    Filed: April 30, 2008
    Publication date: November 27, 2008
    Applicant: FUJITSU LIMITED
    Inventors: Yuko Miyake, Masaaki Matsuoka, Mitsuru Otagiri
  • Publication number: 20080170334
    Abstract: According to an aspect of an embodiment, a magnetic head comprises a magnetic pole; a first return yoke located under a lower side of the magnetic pole; a second return yoke located over an upper side of the magnetic pole; and a side yokes made of a soft magnetic material, located adjacently to the end of the magnetic pole and connecting the first return yoke and the second return yoke.
    Type: Application
    Filed: December 27, 2007
    Publication date: July 17, 2008
    Applicant: Fujitsu Limited
    Inventor: Mitsuru Otagiri
  • Publication number: 20080171232
    Abstract: In the magnetic head, a lower shielding layer and an upper shielding layer of a read-head and a lower magnetic pole of a write-head are electrically connected to a substrate so as to prevent damage of an MR element caused by static electricity and so as not to badly influence reading characteristics of a read-head. The magnetic head comprises: a read-head having a lower shielding layer and an upper shielding layer, which are electrically connected to a substrate via a shunt resistance; and a write-head having a lower magnetic pole, which is electrically connected to the substrate via the shunt resistance, wherein the lower shielding layer and the upper shielding layer are electrically connected to the substrate via a conductive layer, and the lower magnetic pole is electrically connected to the substrate via a conductive layer, which is formed as a base layer of the lower magnetic pole.
    Type: Application
    Filed: October 24, 2007
    Publication date: July 17, 2008
    Applicant: Fujitsu Limited
    Inventors: Tomoka Aoki, Junichi Hashimoto, Mitsuru Otagiri, Hideyuki Akimoto
  • Publication number: 20080081219
    Abstract: The magnetoresistance effect element includes: a magnetization fixing layer; a barrier layer formed on the magnetization fixing layer; and a free layer formed on the barrier layer. The method of producing the magnetoresistance effect element comprises the steps of: forming the magnetization fixing layer on a substrate; forming a metal film as the barrier layer, wherein one part of the metal film on the magnetization fixing layer side is in an amorphous state or a refined crystal state and the other part thereof on the other side is in a crystal state; natural-oxidizing the metal film in an oxidizing atmosphere; forming the free layer on the oxidized metal layer.
    Type: Application
    Filed: May 7, 2007
    Publication date: April 3, 2008
    Applicant: Fujitsu Limited
    Inventors: Kouji Hirano, Mitsuru Otagiri
  • Publication number: 20080061773
    Abstract: A method of evaluating can evaluate the bias magnetic field strength of hard films that construct a magnetoresistance effect read head, the magnetic coercivity of the hard films, and variations in the magnetic domain of shield films from measurement results for the resistance-parallel magnetic field strength characteristics. A magnetizing magnetic field is applied in a direction parallel to the air bearing surface of a magnetoresistance effect read head equipped with hard films to magnetize the hard films in a direction of a horizontal bias magnetic field applied to a free layer of the read element. After this, the resistance of the read element is detected and the resistance-parallel magnetic field strength characteristics of the read head are measured while applying a test magnetic field with increasing and decreasing intensity in a direction parallel to the horizontal bias magnetic field.
    Type: Application
    Filed: February 7, 2007
    Publication date: March 13, 2008
    Inventors: Mitsuru Otagiri, Masato Matsubara
  • Publication number: 20080019045
    Abstract: A perpendicular magnetic head suppresses pole erasing due to a remanent magnetization component of a main pole and is capable of higher density recording. The perpendicular magnetic head is equipped with a main pole that produces magnetic flux toward a medium surface of a recording medium. The main pole is formed by laminating a top thin magnetic layer and a bottom thin magnetic layer in the thickness direction. The top thin magnetic film is formed as a high Bs thin magnetic film with a first saturation flux density and the bottom thin magnetic film is formed as a low Bs thin magnetic film with a second saturation flux density that is lower than the first saturation flux density, and the high Bs thin magnetic film and the low Bs thin magnetic film satisfy the following equation (volume of the high Bs thin magnetic film)×(first saturation flux density) <(volume of the low Bs thin magnetic film)×(second saturation flux density).
    Type: Application
    Filed: September 26, 2007
    Publication date: January 24, 2008
    Applicant: Fujitsu Limited
    Inventors: Mitsuru Otagiri, Yuko Miyake
  • Publication number: 20080002306
    Abstract: The magnetic head is capable of preventing variation of magnetic fields working to a read-element, stably generating output signals and improving production yield. The magnetic head comprises: a read-head including a read-element; and a shield for magnetic-shielding the read-element, the shield has a hexagonal planar shape, and one side of the shield is flush with an air bearing surface of the magnetic head.
    Type: Application
    Filed: September 7, 2006
    Publication date: January 3, 2008
    Inventors: Mitsuru Otagiri, Hideyuki Akimoto, Masaya Kato, Hiroshi Shirataki
  • Publication number: 20070247752
    Abstract: A perpendicular magnetic head suppresses pole erasing due to a remanent magnetization component of a main pole and is capable of higher density recording. The perpendicular magnetic head is equipped with a main pole that produces magnetic flux toward a medium surface of a recording medium as a write head. The main pole is formed by laminating two thin magnetic layers in the thickness direction. Out of the thin magnetic films, a top thin magnetic film is formed as a high Bs thin magnetic film with a first saturation flux density and a bottom thin magnetic film is formed as a low Bs thin magnetic film with a second saturation flux density that is lower than the first saturation flux density, and the high Bs thin magnetic film and the low Bs thin magnetic film satisfy the following equation (volume of the high Bs thin magnetic film)×(first saturation flux density)<(volume of the low Bs thin magnetic film)×(second saturation flux density).
    Type: Application
    Filed: July 12, 2006
    Publication date: October 25, 2007
    Inventors: Mitsuru Otagiri, Yuko Miyake
  • Publication number: 20070211380
    Abstract: The perpendicular magnetic head is capable of solving the problems of side track erasing and pole erasing. The perpendicular magnetic head of the present invention comprises a write-head, which includes a main magnetic pole emitting magnetic fluxes toward a recording medium. An end face of a pole end is formed into a T-shape. A longitudinal pole section of the pole end is made of a low Bs magnetic thin film, whose end face is formed into a rectangle. A transverse pole section of the pole end is made of a high Bs magnetic thin film, whose end face is formed into a rectangle. The low Bs magnetic thin film and the high Bs magnetic thin film are determined by the formula: (area of the end face of the low Bs magnetic thin film)×(saturation magnetic flux density of the low Bs magnetic thin film)>(area of the end face of the high Bs magnetic thin film)×(saturation magnetic flux density of the high Bs magnetic thin film).
    Type: Application
    Filed: July 7, 2006
    Publication date: September 13, 2007
    Inventors: Hideyuki Akimoto, Mitsuru Otagiri, Hiroshi Shirataki
  • Patent number: 6826013
    Abstract: A thin film magnetic head comprising a substrate, a lower magnetic pole provided on the substrate, a write gap layer located on the lower magnetic pole, and an upper magnetic pole located on the gap layer, the upper magnetic pole including a plating base layer in contact with the gap layer, wherein the plating base layer of the upper magnetic pole is made of a magnetic film having a saturation magnetic flux density of 1.2 T or larger. The thin film magnetic head has an increased recording density, and is adapted to recording at an increased frequency.
    Type: Grant
    Filed: May 30, 2001
    Date of Patent: November 30, 2004
    Assignee: Fujitsu Limited
    Inventors: Mitsuru Otagiri, Yuko Miyake, Sanae Shimizu
  • Patent number: 6376108
    Abstract: This invention is to provide a magnetic head consisting of NiFeMo alloy which assures excellent high frequency characteristic and makes easy formation of magnetic domain structure without any heat treatment and thereby contributes to improvement of magnetic recording capability. Magnetic material for a magnetic head includes Ni, Fe and Mo. The composition ratio of NiFeMo is selected under the condition where Ni is 77 to 82 atom %, Fe is 15 to 21 atom %, Mo is under 6 atom %, and magnetic strain constant &lgr;s is in the range of −1×10−6≦&lgr;s ≦10−6.
    Type: Grant
    Filed: December 14, 1999
    Date of Patent: April 23, 2002
    Assignee: Fujitsu Limited
    Inventors: Mitsuru Otagiri, Sanae Takefusa, Yuko Miyake
  • Publication number: 20020044378
    Abstract: A thin film magnetic head comprising a substrate, a lower magnetic pole provided on the substrate, a write gap layer located on the lower magnetic pole, and an upper magnetic pole located on the gap layer, the upper magnetic pole including a plating base layer in contact with the gap layer, wherein the plating base layer of the upper magnetic pole is made of a magnetic film having a saturation magnetic flux density of 1.2 T or larger. The thin film magnetic head has an increased recording density, and is adapted to recording at an increased frequency.
    Type: Application
    Filed: May 30, 2001
    Publication date: April 18, 2002
    Applicant: FUJITSU LIMITED
    Inventors: Mitsuru Otagiri, Yuko Miyake, Sanae Shimizu
  • Patent number: 6157523
    Abstract: A spin valve magnetoresistive head includes a first soft magnetic layer and a second soft magnetic layer having larger internal stress than that of the first magnetic layer. The larger internal stress of the second soft magnetic layer is created by injecting the second soft magnetic layer with a selected type of ion. Also included in the head is a nonmagnetic layer formed between the first soft magnetic layer and the second soft magnetic layer.
    Type: Grant
    Filed: September 6, 1995
    Date of Patent: December 5, 2000
    Assignee: Fujitsu Limited
    Inventors: Hideyuki Kikuchi, Kazuo Kobayashi, Hitoshi Kishi, Mitsuru Otagiri
  • Patent number: 6074535
    Abstract: The present invention relates to a method of fabricating a magnetoresistive head formed by laminating a magnetic layer and a nonmagnetic metal layer including a silver film and used for converting change in magnetic field into change of resistivity of the device. A method of fabricating a magnetoresistive head upon laminating on a substrate a plurality of magnetic layers arranged to put nonmagnetic metal layer therebetween and a bias magnetic layer formed adjacent to one of the magnetic layers to give a magnetization of the specified direction to the magnetic layer, comprising the steps of setting film thicknesses of the nonmagnetic metal layers to be formed, and forming the nonmagnetic metal layers under a condition where temperature of the substrate is held within a temperature range less than an upper limit of a film forming temperature not to cause pin holes in the nonmagnetic metal layer.
    Type: Grant
    Filed: October 31, 1997
    Date of Patent: June 13, 2000
    Assignee: Fujitsu Limited
    Inventors: Hitoshi Kishi, Kazuo Kobayashi, Yasuhiro Kitade, Mitsuru Otagiri, Hideyuki Kikuchi
  • Patent number: 6007643
    Abstract: A magnetoresistive head in which an antiferromagnetic material having superior corrosion resistance is used is disclosed. In the magnetoresistive head, a pair of anti-ferromagnetic layers 24a and 24b are formed while contacting with a soft magnetic layer 23, and the antiferromagnetic layers 24a and 24b are made of a PdMn film.
    Type: Grant
    Filed: August 29, 1997
    Date of Patent: December 28, 1999
    Assignee: Fujitsu Limited
    Inventors: Hitoshi Kishi, Kazuo Kobayashi, Atsushi Tanaka, Yasuhiro Kitade, Yuko Miyake, Mitsuru Otagiri
  • Patent number: 5930085
    Abstract: The present invention relates to a magnetoresistive head having a spin valve MR film for use in a magnetic sensor, a magnetic head or the like. Of two ferromagnetic layers divided by a nonmagnetic metal film, at least ferromagnetic layer on the side being in contact with an antiferromagnetic layer is formed by a cobalt-nickel-iron alloy including at the rate of 5 to 40 atoms % of a nickel and 30 to 95 atoms % of cobalt.
    Type: Grant
    Filed: April 21, 1997
    Date of Patent: July 27, 1999
    Assignee: Fujitsu Limited
    Inventors: Yasuhiro Kitade, Kazuo Kobayashi, Hideyuki Kikuchi, Hitoshi Kishi, Mitsuru Otagiri
  • Patent number: 5729411
    Abstract: A magnetoresistive head in which an antiferromagnetic material having superior corrosion resistance is used is disclosed. In the magnetoresistive head, a pair of anti-ferromagnetic layers 24a and 24b are formed while contacting with a soft magnetic layer 23, and the antiferromagnetic layers 24a and 24b are made of a PdMn film.
    Type: Grant
    Filed: July 9, 1996
    Date of Patent: March 17, 1998
    Assignee: Fujitsu Limited
    Inventors: Hitoshi Kishi, Kazuo Kobayashi, Atsushi Tanaka, Yasuhiro Kitade, Yuko Miyake, Mitsuru Otagiri
  • Patent number: 5661621
    Abstract: A magnetoresistive head used for reading information signals from a magnetic recording medium using a spin valve magnetoresistance effect, comprises a first ferromagnetic layer and a second ferromagnetic layer both are separated by a first nonmagnetic metal layer, a hard magnetic layer formed so as to contact to the second ferromagnetic layer, and a third ferromagnetic layer formed on the hard magnetic layer via a second nonmagnetic metal layer for shutting off exchange coupling and coupled to the second ferromagnetic layer and the hard magnetic layer by static magnetic combination.
    Type: Grant
    Filed: July 31, 1995
    Date of Patent: August 26, 1997
    Assignee: Fujitsu Limited
    Inventors: Kazuo Kobayashi, Hideyuki Kikuchi, Hitoshi Kishi, Mitsuru Otagiri