Patents by Inventor Koichi Otani

Koichi Otani 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: 20110127234
    Abstract: A manufacturing method for a magnetic head includes the steps of; forming a structure on a lower shield, the structure including a lower gap, a main magnetic pole and first and second side gaps; forming first and second side shields; forming an upper gap; and forming an upper shield. In the step of forming the structure, an initial lower gap layer is formed on the lower shield, the initial lower gap layer including a pre-lower-gap portion, and two to-be-removed portions that are located on opposite sides of the pre-lower-gap portion. Then, a protrusion including the main magnetic pole and the first and second side gaps is formed on the pre-lower-gap portion. With the top surface of the protrusion covered with a mask, the initial lower gap layer is etched in part to thereby form the lower gap.
    Type: Application
    Filed: November 30, 2009
    Publication date: June 2, 2011
    Applicant: TDK CORPORATION
    Inventors: Hisayoshi Watanabe, Masachika Hashino, Michitoshi Tsuchiya, Koichi Otani, Tatsuhiro Nojima, Tsutomu Nishinaga, Hideyuki Ukita
  • Patent number: 7948716
    Abstract: A magnetic head includes: a coil; a pole layer; a shield having an end face located in a medium facing surface forward of an end face of the pole layer along a direction of travel of a recording medium; a gap layer between the shield and the pole layer; and a substrate on which the foregoing elements are stacked. The top surface of the pole layer includes: first and second portions with a difference in height therebetween; and a third portion connecting the first and second portions to each other. The first portion has an edge located in the medium facing surface, and the second portion is located farther from the medium facing surface and from the substrate than the first portion. The magnetic head further includes a nonmagnetic layer disposed between the second portion and the gap layer. The nonmagnetic layer has a surface touching the second portion, the surface having an edge located at the boundary between the second and third portions.
    Type: Grant
    Filed: June 4, 2007
    Date of Patent: May 24, 2011
    Assignees: SAE Magnetics (H.K.) Ltd., TDK Corporation
    Inventors: Naoto Matono, Koichi Otani, Tatsuya Harada, Noriaki Kasahara, Takamitsu Sakamoto, Hiroaki Kawashima, Hirotaka Gomi, Kenkichi Anagawa, Norikazu Ota
  • Publication number: 20100302662
    Abstract: A testing method of a wafer provided with a plurality of thin-film magnetic heads is provided. Each of the plurality of thin-film magnetic heads includes a main pole layer, a first test pad formed on the wafer and electrically connected with an extended top end section of the main pole layer and a second test pad formed on the wafer and electrically connected with a back end section of the main pole layer. The testing method includes a step of measuring an electrical resistance between the first test pad and the second test pad, a step of judging whether the measured electrical resistance is within a set range, and a step of discriminating that the thin-film magnetic head is a non-defective product when the measured electrical resistance is within the set range.
    Type: Application
    Filed: May 28, 2009
    Publication date: December 2, 2010
    Applicant: TDK CORPORATION
    Inventors: Isamu TOBA, Yasuhiro HASEGAWA, Koichi OTANI, Takamitsu SAKAMOTO
  • Patent number: 7826175
    Abstract: A thin-film magnetic head includes a first magnetic layer, a flat, spiral-shaped coil, a toroidal-shaped insulating layer covering the coil, and a second magnetic layer touching the insulating layer and disposed to sandwich part of the coil between itself and the first magnetic layer. The second magnetic layer has a recessed portion that enters a space inside the insulating layer. In the recessed portion, the bottom surface of the second magnetic layer includes a first flat portion a part of which touches the top surface of the first magnetic layer, while the top surface of the second magnetic layer includes a second flat portion located in the space and substantially parallel to the first flat portion. In a cross section that divides each of the first and second magnetic layers into two equal portions, the second flat portion is 0.
    Type: Grant
    Filed: May 3, 2007
    Date of Patent: November 2, 2010
    Assignees: TDK Corporation, SAE Magnetics (H.K.) Ltd.
    Inventors: Kenji Yokoyama, Naoto Matono, Tatsuya Harada, Koichi Otani, Hidetaka Kawano
  • Patent number: 7808743
    Abstract: A perpendicular magnetic write head includes an auxiliary magnetic pole layer disposed on a trailing or leading side of a main magnetic pole layer, the auxiliary magnetic pole layer being recessed from the main magnetic pole layer. A nonmagnetic layer is disposed in a layer same as the auxiliary magnetic pole layer and in front of the auxiliary magnetic pole layer, the nonmagnetic layer having an internal stress of a direction same as that of the main magnetic pole layer, and a write shield layer is disposed in a layer same as the auxiliary magnetic pole layer and in front of the auxiliary magnetic pole layer, the write shield layer being separated from the main magnetic pole layer with a gap layer in between. The nonmagnetic layer is arranged to fill up a space between the auxiliary magnetic pole layer and the write shield layer.
    Type: Grant
    Filed: March 5, 2007
    Date of Patent: October 5, 2010
    Assignees: TDK Corporation, Sae Magnetics (H.K.) Ltd.
    Inventors: Naoto Matono, Noriaki Kasahara, Shin Narushima, Takamitsu Sakamoto, Koichi Otani
  • Patent number: 7796359
    Abstract: A magnetic head includes a pole layer, a first and a second shield disposed to sandwich the pole layer, and a nonmagnetic layer disposed around the first shield. The pole layer includes a first portion having an end face located in a medium facing surface, and a second portion that is located farther from the medium facing surface than is the first portion. The second portion is greater in thickness than the first portion. A bottom surface of the second portion is located closer to a substrate than is a bottom surface of the first portion. The first shield has a first top surface portion opposed to the bottom surface of the first portion with the first gap layer in between. The nonmagnetic layer has a second top surface portion opposed to the bottom surface of the second portion with the first gap layer in between.
    Type: Grant
    Filed: August 23, 2007
    Date of Patent: September 14, 2010
    Assignees: TDK Corporation, SAE Magnetics (H.K.) Ltd.
    Inventors: Koichi Otani, Hiromichi Umehara, Naoto Matono, Takamitsu Sakamoto, Noriaki Kasahara, Hidetaka Kawano
  • Patent number: 7787215
    Abstract: A thin film magnetic head is provided, in which thermal protrusion can be suppressed. The thin film magnetic head includes a main magnetic pole layer which conducts a magnetic flux into the recording medium so that the recording medium is magnetized in a direction perpendicular to a surface of the recording medium, a first return yoke layer provided in a trailing side of the main magnetic pole layer, and has a recess in a top surface, a second return yoke layer provided so as to fill at least the recess of the first return yoke layer, and a thermal expansion suppression layer provided in a trailing side of the second return yoke layer. Thus, since the thermal expansion suppression layer can be provided on a surface having no recess, a possibility of a crack in the thermal expansion suppression layer can be eliminated.
    Type: Grant
    Filed: March 29, 2007
    Date of Patent: August 31, 2010
    Assignees: TDK Corporation, SAE Magnetics (H.K.) Ltd.
    Inventors: Shin Narushima, Naoto Matono, Takamitsu Sakamoto, Noriaki Kasahara, Koichi Otani
  • Publication number: 20100084262
    Abstract: The present invention relates to a method for manufacturing a perpendicular recording magnetic head. The method for manufacturing a perpendicular recording magnetic head according to the present invention includes first to third steps. At the first step, a main magnetic pole layer is formed on a foundation layer. At the second step, a main magnetic pole forming mask whose recording-medium-facing surface is of an inverted trapezoidal shape is formed on the main magnetic pole layer. At the third step, a main magnetic pole whose recording-medium-facing surface is of an inverted trapezoidal shape is formed by performing ion milling on a laminated structure including the foundation layer and the main magnetic pole layer from a direction which makes a given angle with a lamination direction according to a bevel angle of the inverted trapezoidal shape.
    Type: Application
    Filed: October 2, 2008
    Publication date: April 8, 2010
    Applicant: TDK CORPORATION
    Inventors: Hiromichi Umehara, Shin Narushima, Michitaka Nishiyama, Noriaki Kasahara, Koichi Otani
  • Publication number: 20090273863
    Abstract: A perpendicular recording thin-film magnetic head comprises a main magnetic pole having a tip main magnetic pole part extending in a height direction from a medium-opposing surface and a base main magnetic pole part connected to the tip main magnetic pole part on a side opposite from the medium-opposing surface side and wider than the tip main magnetic pole part in a track width direction; a return yoke extending in the height direction from the medium-opposing surface and magnetically coupling with the base main magnetic pole part at a position distanced from the medium-opposing surface in the height direction, while opposing the tip main magnetic pole part through a write gap layer in a bit length direction in the medium-opposing surface; and a main magnetic pole adjacent magnetic shield layer extending along at least part of side faces of the main magnetic pole other than the medium-opposing surface as seen in a laminating direction, while holding a nonmagnetic layer between the main magnetic pole and the
    Type: Application
    Filed: December 13, 2007
    Publication date: November 5, 2009
    Applicants: TDK CORPORATION, SAE MAGNETICS (H.K.) LTD.
    Inventors: Hidetaka Kawano, Hiromichi Umehara, Takamitsu Sakamoto, Koichi Otani, Noriaki Kasahara, Naoto Matono
  • Publication number: 20090052094
    Abstract: A magnetic head includes a pole layer, a first and a second shield disposed to sandwich the pole layer, and a nonmagnetic layer disposed around the first shield. The pole layer includes a first portion having an end face located in a medium facing surface, and a second portion that is located farther from the medium facing surface than is the first portion. The second portion is greater in thickness than the first portion. A bottom surface of the second portion is located closer to a substrate than is a bottom surface of the first portion. The first shield has a first top surface portion opposed to the bottom surface of the first portion with the first gap layer in between. The nonmagnetic layer has a second top surface portion opposed to the bottom surface of the second portion with the first gap layer in between.
    Type: Application
    Filed: August 23, 2007
    Publication date: February 26, 2009
    Applicants: TDK CORPORATION, SAE MAGNETICS (H.K.) LTD.
    Inventors: Koichi Otani, Hiromichi Umehara, Naoto Matono, Takamitsu Sakamoto, Noriaki Kasahara, Hidetaka Kawano
  • Publication number: 20080297953
    Abstract: A magnetic head includes: a coil; a pole layer; a shield having an end face located in a medium facing surface forward of an end face of the pole layer along a direction of travel of a recording medium; a gap layer between the shield and the pole layer; and a substrate on which the foregoing elements are stacked. The top surface of the pole layer includes: first and second portions with a difference in height therebetween; and a third portion connecting the first and second portions to each other. The first portion has an edge located in the medium facing surface, and the second portion is located farther from the medium facing surface and from the substrate than the first portion. The magnetic head further includes a nonmagnetic layer disposed between the second portion and the gap layer. The nonmagnetic layer has a surface touching the second portion, the surface having an edge located at the boundary between the second and third portions.
    Type: Application
    Filed: June 4, 2007
    Publication date: December 4, 2008
    Applicants: SAE MAGNETICS (H.K.) LTD., TDK CORPORATION
    Inventors: Naoto Matono, Koichi Otani, Tatsuya Harada, Noriaki Kasahara, Takamitsu Sakamoto, Hiroaki Kawashima, Hirotaka Gomi, Kenkichi Anagawa, Norikazu Ota
  • Publication number: 20080273273
    Abstract: A thin-film magnetic head includes a first magnetic layer, a flat, spiral-shaped coil, a toroidal-shaped insulating layer covering the coil, and a second magnetic layer touching the insulating layer and disposed to sandwich part of the coil between itself and the first magnetic layer. The second magnetic layer has a recessed portion that enters a space inside the insulating layer. In the recessed portion, the bottom surface of the second magnetic layer includes a first flat portion a part of which touches the top surface of the first magnetic layer, while the top surface of the second magnetic layer includes a second flat portion located in the space and substantially parallel to the first flat portion. In a cross section that divides each of the first and second magnetic layers into two equal portions, the second flat portion is 0.
    Type: Application
    Filed: May 3, 2007
    Publication date: November 6, 2008
    Applicants: TDK CORPORATION, SAE MAGNETICS (H.K.) LTD.
    Inventors: Kenji Yokoyama, Naoto Matono, Tatsuya Harada, Koichi Otani, Hidetaka Kawano
  • Publication number: 20080253034
    Abstract: The present invention is directed to providing a perpendicular magnetic write head which can suppress unintended erasure of information written on a write medium at a non-writing time by optimizing a magnetic domain structure of main component elements that are engaged in writing operation. In the perpendicular magnetic write head, an auxiliary magnetic pole layer is disposed on a trailing or leading side of a main magnetic pole layer, the auxiliary magnetic pole layer being recessed from the main magnetic pole layer. When the main magnetic pole layer has a tensile stress as its internal stress, a nonmagnetic layer disposed in a layer same as the auxiliary magnetic pole layer and in an area in front of the auxiliary magnetic pole layer, also has a tensile stress as its internal stress.
    Type: Application
    Filed: March 5, 2007
    Publication date: October 16, 2008
    Applicants: TDK CORPORATION, SAE MAGNETICS (H.K.) LTD.
    Inventors: Naoto Matono, Noriaki Kasahara, Shin Narushima, Takamitsu Sakamoto, Koichi Otani
  • Publication number: 20080253032
    Abstract: A thin film magnetic head is provided, in which thermal protrusion can be suppressed. The thin film magnetic head includes a main magnetic pole layer which conducts a magnetic flux into the recording medium so that the recording medium is magnetized in a direction perpendicular to a surface of the recording medium, a first return yoke layer provided in a trailing side of the main magnetic pole layer, and has a recess in a top surface, a second return yoke layer provided so as to fill at least the recess of the first return yoke layer, and a thermal expansion suppression layer provided in a trailing side of the second return yoke layer. Thus, since the thermal expansion suppression layer can be provided on a surface having no recess, a possibility of a crack in the thermal expansion suppression layer can be eliminated.
    Type: Application
    Filed: March 29, 2007
    Publication date: October 16, 2008
    Applicants: TDK CORPORATION, SAE MAGNETICS (H.K.) LTD.
    Inventors: Shin Narushima, Naoto Matono, Takamitsu Sakamoto, Noriaki Kasahara, Koichi Otani
  • Publication number: 20080247087
    Abstract: A magnetic head incorporates: a medium facing surface; a coil; a pole layer; first and second shields disposed to sandwich the pole layer therebetween; a first gap layer disposed between the first shield and the pole layer; a second gap layer disposed between the second shield and the pole layer; and a substrate. The first shield is located closer to the substrate than the second shield. The first shield has a first layer and a second layer disposed between the first layer and the first gap layer.
    Type: Application
    Filed: April 6, 2007
    Publication date: October 9, 2008
    Applicants: TDK CORPORATION, SAE MAGNETICS (H.K.) LTD.
    Inventors: Koichi Otani, Naoto Matono, Tatsuya Harada, Kenji Yokoyama, Hidetaka Kawano
  • Publication number: 20080239580
    Abstract: A magnetic head incorporates: a medium facing surface; a coil; a pole layer; first and second shields disposed to sandwich the pole layer therebetween; a first gap layer disposed between the first shield and the pole layer; a second gap layer disposed between the second shield and the pole layer; and a substrate. The first shield is located closer to the substrate than the second shield. The magnetic head further incorporates an antireflection film disposed between the first shield and the first gap layer or between the first gap layer and the pole layer. The pole layer is formed by frame plating.
    Type: Application
    Filed: March 26, 2007
    Publication date: October 2, 2008
    Applicants: TDK CORPORATION, SAE MAGNETICS (H.K.) LTD.
    Inventors: Tatsuya Harada, Koichi Otani, Hidetaka Kawano, Kenji Yokoyama, Naoto Matono
  • Patent number: 6003380
    Abstract: A pressure sensor prevents the occurrence of a large deformation or breakage of the diaphragm in a strain gage-type pressure sensor utilizing a thin plate-shaped insulating body as the diaphragm. The pressure sensor comprises an insulating diaphragm having a strain gage on its surface and a substrate positioned opposing the surface of the diaphragm on which the strain gage is mounted and kept a predetermined distance away from the surface. The diaphragm can be formed of material such as ceramic of alumina, zirconia or the like, silicon or crystal. The substrate can be formed of either the same material as the diaphragm, or the surface opposing the diaphragm can be formed of an insulator disposed on metal. The diaphragm and the substrate can be affixed using a low-melting glass.
    Type: Grant
    Filed: September 11, 1997
    Date of Patent: December 21, 1999
    Assignee: Fujikoki Corporation
    Inventors: Keiji Sasaki, Koichi Otani, Yukio Koganei
  • Patent number: 5863448
    Abstract: A method of manufacturing a thin film magnetic head. In one embodiment, a lower magnetic pole and a magnetic film are formed on a substrate that is covered by an insulating film. A mask is then formed on the lower magnetic pole. The mask and the lower magnetic pole are then ion milled to the same width. A protective film is then formed to sufficiently cover then lower magnetic pole and the mask. The protective film is then polished to expose the mask. An exposed surface of the mask and the protective film are then planarized and the remaining make is then removed by wet etching. A concavity is formed at a position in the lower magnetic pole in the protective film. An upper magnetic pole is then formed by electroplating on the concavity. The mask is formed by electroplating Cu or permalloy, or by patterning photoresist.
    Type: Grant
    Filed: November 27, 1996
    Date of Patent: January 26, 1999
    Assignee: Read-Rite Corporation
    Inventors: Koichi Otani, Daisuke Iitsuka, Ryuji Kobo, Masayuki Hamakawa
  • Patent number: 5728969
    Abstract: A granular explosive is obtained by mixing porous prill ammonium nitrate having an average particle size of 0.5 to 3.0 mm with a liquid aromatic dinitro compound and optionally a metal powder. Explosives having high sensitivity and power can be obtained by a simple and easy process.
    Type: Grant
    Filed: March 7, 1997
    Date of Patent: March 17, 1998
    Assignees: Mitsubishi Chemical Corporation, Nippon Kayaku Kabushiki Kaisha
    Inventors: Koichi Otani, Seiichi Yoshida, Yoshiyuki Ikeda, Hiroyuki Taniguchi
  • Patent number: 5675119
    Abstract: A granular explosive is obtained by mixing porous prill ammonium nitrate having an average particle size of 0.5 to 3.0 mm with a liquid aromatic dinitro compound and optionally a metal powder. Explosives having high sensitivity and power can be obtained by a simple and easy process.
    Type: Grant
    Filed: August 1, 1995
    Date of Patent: October 7, 1997
    Assignees: Mitsubishi Chemical Corporation, Nippon Kayaku Kabushiki Kaisha
    Inventors: Koichi Otani, Seiichi Yoshida, Yoshiyuki Ikeda, Hiroyuki Taniguchi