Patents by Inventor Katsuhiko Koui

Katsuhiko Koui 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).

  • Magnetic head pole including laminated structure having magnetic and nonmagnetic layers
    Patent number: 8755147
    Abstract: According to one embodiment, a magnetic head includes a main pole configured to apply a recording magnetic field to a recording layer of a recording medium, a return pole opposed to the main pole with a write gap therebetween, and a high-frequency oscillator between respective facing surfaces of the main pole and the return pole and configured to produce a high-frequency magnetic field. At least one of the main and return poles faces the high-frequency oscillator and includes a laminated structure portion includes a magnetic layer and a nonmagnetic layer laminated to one another.
    Type: Grant
    Filed: September 5, 2013
    Date of Patent: June 17, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takuya Matsumoto, Kenichiro Yamada, Masayuki Takagishi, Katsuhiko Koui, Hitoshi Iwasaki
  • MAGNETIC HEAD, MAGNETIC HEAD ASSEMBLY, AND MAGNETIC RECORDING-REPRODUCING DEVICE
    Publication number: 20140160598
    Abstract: A magnetic head includes a main magnetic pole, a trailing shield that forms a magnetic circuit with the main magnetic pole, a spin torque oscillator that is provided between the main magnetic pole and the trailing shield, a first cooling layer that partially has a Heusler structure, and a second cooling layer that is provided on the first cooling layer and mainly comprised of silver. The first cooling layer and the second cooling layer are provided either between the main magnetic pole and spin torque oscillator or between the trailing shield and the spin torque oscillator, with either of the two cooling layers being disposed closer to the spin torque oscillator. A third cooling layer may be formed to be in contact with the first cooling layer.
    Type: Application
    Filed: June 11, 2013
    Publication date: June 12, 2014
    Inventors: Masahiro TAKASHITA, Shuichi MURAKAMI, Naoki HASE, Katsuhiko KOUI
  • MAGNETIC HEAD, MAGNETIC HEAD ASSEMBLY, AND MAGNETIC RECORDING/REPRODUCTION APPARATUS
    Publication number: 20140146420
    Abstract: According to one embodiment, a magnetic head includes a spin torque oscillator formed between a main magnetic pole and auxiliary magnetic pole. The spin torque oscillator includes a transmission-type spin transfer layer, first interlayer, oscillation layer, second interlayer, and reflection-type spin transfer layer. The transmission-type spin transfer layer includes a first perpendicular magnetization film and first interface magnetic layer. The first interface magnetic layer contains at least one element selected from Fe, Co, and Ni, and at least one element selected from Cr, V, Mn, Ti, and Sc. The reflection-type spin transfer layer includes a second perpendicular magnetization film.
    Type: Application
    Filed: December 9, 2013
    Publication date: May 29, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Mariko Shimizu, Katsuhiko Koui, Shuichi Murakami, Hiromi Yuasa
  • Magnetic recording head, head gimbal assembly with the same, and disk drive
    Patent number: 8730616
    Abstract: According to one embodiment, a magnetic recording head includes a main pole, a trailing shield opposing the main pole with a write gap therebetween, and a high-frequency oscillator between a distal end portion of the main pole and the trailing shield configured to produce a high-frequency magnetic field. The high-frequency oscillator includes a lower end surface facing the recording medium and an upper end surface substantially parallel to the lower end surface. The width of the lower end surface in a track-width direction is smaller than that of the upper end surface.
    Type: Grant
    Filed: August 14, 2012
    Date of Patent: May 20, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kenichiro Yamada, Yusuke Tomoda, Tomoko Taguchi, Katsuhiko Koui
  • Magnetic head and magnetic recording/reproduction apparatus that decreases oscillation driving voltage of a spin torque oscillation element
    Patent number: 8724262
    Abstract: A magnetic head is provided, including a filling layer formed on the side of a spin torque oscillation element between the main magnetic pole and the auxiliary magnetic pole, the filling layer being divided into an insulator region and a metal region from a first interface as a boundary. The insulator region is formed from a side of a spin injection layer to a side of a nonmagnetic interlayer, and to a side of one portion of an oscillation layer. The first interface is closer to the oscillation layer by 0.5 nm or more than a second interface between the nonmagnetic interlayer and the oscillation layer. A magnetic recording/reproduction apparatus having the magnetic head is also provided.
    Type: Grant
    Filed: May 28, 2013
    Date of Patent: May 13, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Katsuhiko Koui
  • Magnetic recording head and magnetic recording apparatus including the same
    Patent number: 8717705
    Abstract: According to one embodiment, a magnetic recording head includes a facing surface configured to face a recording medium, a main magnetic pole configured to apply a recording magnetic field to a recording layer of the recording medium, and a high-frequency oscillator disposed near to a trailing side of the main magnetic pole and configured to apply a high-frequency magnetic field to the recording layer. An angle defined between a recording magnetic field applied from the main magnetic pole to the recording medium and the facing surface is 0 to 85° in a region between a trailing side end of the main magnetic pole and a trailing side end of the high-frequency oscillator.
    Type: Grant
    Filed: May 17, 2013
    Date of Patent: May 6, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kenichiro Yamada, Naoyuki Narita, Katsuhiko Koui, Akihiko Takeo
  • Recording head with high-frequency oscillator and bi-layer main pole height/width arrangement
    Patent number: 8705204
    Abstract: According to one embodiment, a main pole of a recording head includes a first magnetic pole layer and a second magnetic pole layer laminated on the trailing side of the first magnetic pole layer. The first magnetic pole layer includes a tapered portion and a first tip portion. The second magnetic pole layer includes a tapered portion and a second tip portion. A width in a track direction of the second tip portion is smaller than that of the first tip portion. The high-frequency oscillator is between the second tip portion and the trailing shield and includes a width in the track direction substantially equal to the width in the track direction of the second tip portion, and a height of the first tip portion is taller than that of the second tip portion.
    Type: Grant
    Filed: August 21, 2012
    Date of Patent: April 22, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tomoko Taguchi, Kenichiro Yamada, Katsuhiko Koui, Tomomi Funayama, Norihito Fujita
  • MICROWAVE-ASSISTED MAGNETIC RECORDING HEAD, METHOD OF MANUFACTURING THE SAME, MAGNETIC HEAD ASSEMBLY USING THE SAME, AND MAGNETIC RECORDING/REPRODUCTION APPARATUS
    Publication number: 20140078620
    Abstract: According to one embodiment, a magnetic recording head manufacturing method includes forming a spin torque oscillator layer on a main magnetic pole layer, forming a mask on the spin torque oscillator layer, processing the spin torque oscillator layer by performing ion beam etching through the mask, and partially modifying the main magnetic pole layer through the mask. The partially modifying the main magnetic pole layer makes it possible to decrease the saturation flux density of the main magnetic pole layer in the modified portion, and form an unmodified main magnetic pole portion covered with the mask, and a modified portion around the main magnetic pole.
    Type: Application
    Filed: January 29, 2013
    Publication date: March 20, 2014
    Applicants: TDK CORPORATION, KABUSHIKI KAISHA TOSHIBA
    Inventors: Satoshi SHIROTORI, Katsuhiko KOUI, Shinobu SUGIMURA, Norihito FUJITA, Akihiko TAKEO, Min LI, Ruhang DING
  • Magnetic recording head with high frequency oscillator and disk drive with the same
    Patent number: 8675308
    Abstract: According to one embodiment, a magnetic recording head includes a disk-facing surface configured to face a recording layer of a recording medium, a main magnetic pole includes a distal end located on the disk-facing surface and configured to apply a recording magnetic field to the recording layer of the recording medium, a leading shield on a leading side of the main magnetic pole, opposed to the distal end of the main magnetic pole across a gap, a high-frequency oscillator between the leading shield and the distal end of the main magnetic pole, and a recording coil configured to excite the main magnetic pole with a magnetic field.
    Type: Grant
    Filed: November 19, 2012
    Date of Patent: March 18, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kenichiro Yamada, Takuya Matsumoto, Naoyuki Narita, Tomoko Taguchi, Katsuhiko Koui, Akihiko Takeo
  • MAGNETIC HEAD, METHOD OF MANUFACTURING THE SAME, AND MAGNETIC RECORDING/REPRODUCTION APPARATUS
    Publication number: 20140009853
    Abstract: According to one embodiment, a magnetic head manufacturing method includes forming a protective layer on the surfaces of a main magnetic pole layer, a processed spin torque oscillator, and a mask formed on the spin torque oscillator, and further performing ion beam etching on the main magnetic pole layer and the protective layer on the surface of the main magnetic pole layer through the mask such that the protective layer is left behind on the side surfaces of the spin torque oscillator and removed from the surface of the main magnetic pole layer, thereby processing the main magnetic pole layer such that its side surfaces have a shape tapered toward the substrate.
    Type: Application
    Filed: October 22, 2012
    Publication date: January 9, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Satoshi Shirotori, Katsuhiko Koui, Shinobu Sugimura, Norihito Fujita, Akihiko Takeo
  • MAGNETIC HEAD POLE INCLUDING LAMINATED STRUCTURE HAVING MAGNETIC AND NONMAGNETIC LAYERS
    Publication number: 20140002926
    Abstract: According to one embodiment, a magnetic head includes a main pole configured to apply a recording magnetic field to a recording layer of a recording medium, a return pole opposed to the main pole with a write gap therebetween, and a high-frequency oscillator between respective facing surfaces of the main pole and the return pole and configured to produce a high-frequency magnetic field. At least one of the main and return poles faces the high-frequency oscillator and includes a laminated structure portion includes a magnetic layer and a nonmagnetic layer laminated to one another.
    Type: Application
    Filed: September 5, 2013
    Publication date: January 2, 2014
    Inventors: Takuya MATSUMOTO, Kenichiro YAMADA, Masayuki TAKAGISHI, Katsuhiko KOUI, Hitoshi IWASAKI
  • MAGNETIC RECORDING HEAD, AND DISK DRIVE COMPRISING THE SAME
    Publication number: 20140002924
    Abstract: According to one embodiment, a magnetic recording head includes a disk-facing surface configured to face a recording layer of a recording medium, a main magnetic pole includes a distal end located on the disk-facing surface and configured to apply a recording magnetic field to the recording layer of the recording medium, a leading shield on a leading side of the main magnetic pole, opposed to the distal end of the main magnetic pole across a gap, a high-frequency oscillator between the leading shield and the distal end of the main magnetic pole, and a recording coil configured to excite the main magnetic pole with a magnetic field.
    Type: Application
    Filed: November 19, 2012
    Publication date: January 2, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kenichiro YAMADA, Takuya MATSUMOTO, Naoyuki NARITA, Tomoko TAGUCHI, Katsuhiko KOUI, Akihiko TAKEO
  • Magnetic head and magnetic recording and reproducing device
    Patent number: 8605391
    Abstract: According to one embodiment, a magnetic head has a main magnetic pole, a write-shield constituting the main magnetic pole and a magnetic circuit, and a spin torque oscillation element provided between the main magnetic pole and the write-shield. The spin torque oscillation element is provided with a first oscillation layer, a nonmagnetic spin sink layer, a second oscillation layer, a nonmagnetic intermediate layer, and a spin injection layer provided in sequence from the write-shield side to the main magnetic pole side. The nonmagnetic spin sink layer is formed of at least one element selected from the group consisting of Ru, Rh, Ta, W, Cr, Ir, Mo, Re, Nb, Pt, and Pd.
    Type: Grant
    Filed: June 22, 2012
    Date of Patent: December 10, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Katsuhiko Koui, Shuichi Murakami, Mariko Kitazaki, Yusuke Tomoda, Norihito Fujita
  • MAGNETIC RECORDING HEAD, MAGNETIC HEAD ASSEMBLY, AND MAGNETIC RECORDING/ REPRODUCTION APPARATUS
    Publication number: 20130314820
    Abstract: According to one embodiment, a magnetic recording head includes a main magnetic pole, an auxiliary magnetic pole, and a spin torque oscillator formed between them. The spin torque oscillator includes a main oscillation layer and spin sink layer as an oscillation layer. The spin sink layer contains one of iron and cobalt, and at least one element selected from the group consisting of platinum, palladium, ruthenium, tantalum, chromium, terbium, gadolinium, europium, dysprosium, and samarium.
    Type: Application
    Filed: December 17, 2012
    Publication date: November 28, 2013
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Mariko SHIMIZU, Katsuhiko KOUI, Shuichi MURAKAMI, Masahiro TAKASHITA
  • Radio frequency magnetic field assisted recording head, head assembly, amd recording apparatus
    Patent number: 8559134
    Abstract: A recording head including a first electrode, a first magnetic layer, a second magnetic layer, a first intermediate layer, a third magnetic layer, a second electrode, and a magnetic pole. A product of saturated magnetization of the first magnetic layer and a lateral area of the first magnetic layer is larger than a product of saturated magnetization of the third magnetic layer and a lateral area of the third magnetic layer.
    Type: Grant
    Filed: December 14, 2011
    Date of Patent: October 15, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kenichiro Yamada, Hitoshi Iwasaki, Katsuhiko Koui
  • Magnetic recording head and magnetic recording/reproducing apparatus using the same
    Patent number: 8553359
    Abstract: A magnetic recording head includes a magnetic pole, a spin torque oscillator, a first shield and a second shield. The magnetic pole has an air-bearing surface. The spin torque oscillator is provided so that a first side of the spin torque oscillator faces the magnetic pole in a first direction parallel to the air-bearing surface. The first shield includes a granular magnetic material, and is provided so that two portions of the first shield sandwich the spin torque oscillator in a second direction which is parallel to the air-bearing surface and perpendicular to the first direction. The second shield is provided on a second side of the spin torque oscillator opposite to the first side.
    Type: Grant
    Filed: August 10, 2010
    Date of Patent: October 8, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kenichiro Yamada, Katsuhiko Koui, Mariko Kitazaki, Masayuki Takagishi, Tomomi Funayama, Masahiro Takashita, Soichi Oikawa, Akihiko Takeo
  • MAGNETIC RECORDING HEAD, HEAD GIMBAL ASSEMBLY WITH THE SAME, AND DISK DRIVE
    Publication number: 20130250456
    Abstract: According to one embodiment, a magnetic recording head includes a main pole, a trailing shield opposing the main pole with a write gap therebetween, and a high-frequency oscillator between a distal end portion of the main pole and the trailing shield configured to produce a high-frequency magnetic field. The high-frequency oscillator includes a lower end surface facing the recording medium and an upper end surface substantially parallel to the lower end surface. The width of the lower end surface in a track-width direction is smaller than that of the upper end surface.
    Type: Application
    Filed: August 14, 2012
    Publication date: September 26, 2013
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kenichiro YAMADA, Yusuke TOMODA, Tomoko TAGUCHI, Katsuhiko KOUI
  • RECORDING HEAD AND DISK DRIVE WITH THE SAME
    Publication number: 20130215532
    Abstract: According to one embodiment, a main pole of a recording head includes a first magnetic pole layer and a second magnetic pole layer laminated on the trailing side of the first magnetic pole layer. The first magnetic pole layer includes a tapered portion and a first tip portion. The second magnetic pole layer includes a tapered portion and a second tip portion. A width in a track direction of the second tip portion is smaller than that of the first tip portion. The high-frequency oscillator is between the second tip portion and the trailing shield and includes a width in the track direction substantially equal to the width in the track direction of the second tip portion, and a height of the first tip portion is taller than that of the second tip portion.
    Type: Application
    Filed: August 21, 2012
    Publication date: August 22, 2013
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tomoko TAGUCHI, Kenichiro YAMADA, Katsuhiko KOUI, Tomomi FUNAYAMA, Norihito FUJITA
  • Spin injection layer robustness for microwave assisted magnetic recording
    Patent number: 8488373
    Abstract: A spin transfer (torque) oscillator (STO) with a non-magnetic spacer formed between a spin injection layer (SIL) and a field generation layer (FGL), and with an interfacial layer comprised of Fe(100-V)CoV where v is from 5 to 100 atomic % formed between the SIL and non-magnetic spacer is disclosed. A composite seed layer made of Ta and a metal layer having a fcc(111) or hcp(001) texture is used to enhance perpendicular magnetic anisotropy (PMA) in the STO device. The interfacial layer quenches SIL oscillations and thereby stabilizes the SIL against FGL oscillations. The interfacial layer preferably has a thickness from 5 to 50 Angstroms and enhances amplitude (dR/R) in the STO device. The STO device may have a top SIL or bottom SIL configuration. The SIL is typically a laminated structure such as (Co/Ni)X where x is between 5 and 50.
    Type: Grant
    Filed: October 3, 2011
    Date of Patent: July 16, 2013
    Assignees: TDK Corporation, Kabushiki Kaisha Toshiba
    Inventors: Kunliang Zhang, Min Li, Yuchen Zhou, Soichi Oikawa, Hitoshi Iwasaki, Kenichiro Yamada, Katsuhiko Koui
  • Spin oscillator or magnetic recorder including multiple injection layers in the magnetic recording head
    Patent number: 8472140
    Abstract: A magnetic recorder includes: a magnetic recording medium; a reproducing head; a magnetic recording head including: a main magnetic pole; a first magnetic layer containing a TM alloy; a second magnetic layer containing a TM alloy or an RE-TM alloy; a third magnetic layer containing an RE-TM alloy; a first intermediate layer provided between the first magnetic layer and the second magnetic layer; and a second intermediate layer provided between the second magnetic layer and the third magnetic layer; and a signal processing portion which performs signal writing into the magnetic recording medium by using the magnetic recording head and reading from the magnetic recording medium by using the reproducing head.
    Type: Grant
    Filed: February 24, 2012
    Date of Patent: June 25, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kenichiro Yamada, Hitoshi Iwasaki, Masayuki Takagishi, Tomomi Funayama, Masahiro Takashita, Katsuhiko Koui, Mariko Kitazaki, Soichi Oikawa