Patents by Inventor Migaku Takahashi

Migaku Takahashi 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).

  • Patent number: 8034471
    Abstract: In a perpendicular magnetic recording medium in which at least a soft magnetic underlayer, an orientation control layer, a magnetic recording layer and a protective layer are formed on a non-magnetic substrate in order from the bottom, the orientation control layer has a laminated structure of two or more layers including an intermediate layer and a seed layer which is disposed closer to the non-magnetic substrate than the intermediate layer. The seed layer includes two or more kinds of elements having a face-centered cubic structure, has face-centered cubic (111) plane crystals oriented in a direction perpendicular to a substrate surface, and has a pseudo-hexagonal structure.
    Type: Grant
    Filed: August 5, 2009
    Date of Patent: October 11, 2011
    Assignees: Showa Denko K.K., Kabushiki Kaisha Toshiba, Tohoku University
    Inventors: Shinichi Ishibashi, Migaku Takahashi, Shin Saito, Yuzo Sasaki, Atsushi Hashimoto, Gohei Kurokawa, Tomoyuki Maeda, Akihiko Takeo
  • Patent number: 8034472
    Abstract: The present invention provides a magnetic recording medium which is capable of improving the perpendicular orientation of a perpendicular magnetic recording layer while maintaining a writing performance during recording and obtaining both an improvement in the perpendicular orientation and fine magnetic crystal particles with a uniform diameter, and which enables information to be recorded or reproduced at high density, a method of manufacturing the same, and a magnetic recording/reproducing apparatus. A magnetic recording medium 10 according to the present invention includes at least a soft magnetic underlayer 2, an orientation control layer 3, a magnetic recording layer 4, and a protective layer 5 formed on a non-magnetic substrate 1. The orientation control layer 3 has a seed layer 6 and an intermediate layer 7. The seed layer 6 is made of a Cu—Ti alloy that has a face-centered cubic structure and includes Cu as a main component.
    Type: Grant
    Filed: August 17, 2009
    Date of Patent: October 11, 2011
    Assignees: Showa Denko K.K., Kabushiki Kaisha Toshiba, Tohoku University
    Inventors: Shinichi Ishibashi, Migaku Takahashi, Shin Saito, Yuzo Sasaki, Atsushi Hashimoto, Gohei Kurokawa, Tomoyuki Maeda, Akihiko Takeo
  • Patent number: 8012613
    Abstract: A magnetic recording medium is provided, which has at least one soft magnetic layer, at least one seed layer, at least one underlayer and at least one perpendicular magnetic recording layer, and is characterized in that the or each seed layer is comprised of a covalently bonded material. The covalently bonded material preferably predominantly comprises a nitride having a hexagonal crystal structure, more preferably, predominantly comprises aluminum nitride having a hexagonal wurtzite crystal structure. This magnetic recording medium is superior in recording and reproducing an information with high density.
    Type: Grant
    Filed: June 6, 2008
    Date of Patent: September 6, 2011
    Assignees: Showa Denko K.K., Toshiba Corporation, Tohoku University
    Inventors: Migaku Takahashi, Shin Saito, Tomoyuki Maeda, Akihiko Takeo, Yuzo Sasaki, Ryuji Sakaguchi
  • Publication number: 20110151280
    Abstract: A perpendicular magnetic recording medium including at least a soft under layer, an orientation control layer, a magnetic recording layer and a protective layer on a non-magnetic substrate, wherein the orientation control layer is composed of three or more layers including a seed layer, a first intermediate layer and a second intermediate layer sequentially, formed in that order from the substrate side, the crystal grains that constitute the first intermediate layer are epitaxially grown on the crystal grains of the seed layer, the crystal grains that constitute the second intermediate layer are epitaxially grown on the crystal grains of the first intermediate layer, and the crystal grains that constitute the second intermediate layer are finer than the crystal grains that constitute the first intermediate layer.
    Type: Application
    Filed: August 28, 2008
    Publication date: June 23, 2011
    Applicant: SHOWA DENKO K.K.
    Inventors: Migaku Takahashi, Shin Saito, Gohei Kurokawa, Yuzo Sasaki, Tatsu Komatsuda, Atsushi Hashimoto, Akihiko Takeo, Tomoyuki Maeda
  • Patent number: 7943248
    Abstract: Perpendicular magnetic recording media enabling high-density recording and reproduction of information, as well as a production process thereof, and a magnetic recording and reproducing apparatus, are provided. Perpendicular magnetic recording media, having at least a soft magnetic underlayer and perpendicular magnetic recording layer on a disc-shaped nonmagnetic substrate, in which the soft magnetic underlayer has at least two soft magnetic layers, and Ru or Re between the two soft magnetic layers, are provided; the easy axis of magnetization of the soft magnetic underlayer has a desired direction; the easy axis of magnetization of the soft magnetic underlayer is substantially distributed in a direction except a radial direction of the nonmagnetic substrate, and, the bias magnetic field of the antiferromagnetic coupling in the direction of the easy axis of magnetization of the soft magnetic underlayer is 10 Oersteds (790 A/m) or greater.
    Type: Grant
    Filed: January 31, 2006
    Date of Patent: May 17, 2011
    Assignees: Tohoku University, Showa Denko K.K., Kabushiki Kaisha Toshiba
    Inventors: Migaku Takahashi, Masahiro Oka, Akira Kikitsu
  • Patent number: 7891932
    Abstract: A working rod with a tip end extending into a vacuum process chamber and moving in the axial direction, two static-pressure gas bearings supporting the rod in the non-contact manner, and an internal moving body of a magnet coupling type driving mechanism driving the rod are housed in a rod housing cylindrical portion leading to the vacuum process chamber, and an exhaust portion by suction is provided at a part of the rod housing cylindrical portion so that the pressure of the rod housing cylindrical portion is lowered than the pressure of the vacuum process chamber by the exhaust from the exhaust portion.
    Type: Grant
    Filed: October 25, 2006
    Date of Patent: February 22, 2011
    Assignees: SMC Corporation, Tohoku University
    Inventors: Soichi Sato, Takashi Abe, Eiko Miyasato, Migaku Takahashi, Masakiyo Tsunoda
  • Patent number: 7879466
    Abstract: The invention provides a perpendicular recording medium with high recording density, and a magnetic recording and reproducing apparatus, by improving the function of magnetic anisotropy of a soft magnetic underlayer. The perpendicular recording medium has at least a soft magnetic underlayer and a perpendicular magnetic recording layer on a non-magnetic substrate, wherein when Ku? (erg/cm3) is defined as a perpendicular magnetic anisotropic energy, and Ms (emu/cm 3) is defined as a saturation magnetization of the soft magnetic underlayer, Ku? of the soft magnetic underlayer has a negative value and Ku?<?2?Ms2. As a result, the easy axis of a magnetization of a soft magnetic underlayer is oriented strongly in the substrate surface plane, which is effective to suppress the WATE phenomena and spike noise.
    Type: Grant
    Filed: March 29, 2006
    Date of Patent: February 1, 2011
    Assignees: Tohoku University, Showa Denko K.K., Kabushiki Kaisha Toshiba
    Inventors: Migaku Takahashi, Masahiro Oka, Akira Kikitsu
  • Publication number: 20110007420
    Abstract: An MR element in a CPP structure includes a spacer layer made of Cu, a magnetic pinned layer containing CoFe and a free layer containing CoFe that are laminated to sandwich the spacer layer. The free layer is located below the magnetic pinned layer. The free layer is oriented in a (001) crystal plane, the spacer layer is formed and oriented in a (001) crystal plane on the (001) crystal plane of the free layer. Therefore, in a low resistance area where an area resistivity (AR) of the MR element is, for example, lower than 0.3 ?·?m2, an MR element that has a large variation of a resistance is obtained.
    Type: Application
    Filed: July 10, 2009
    Publication date: January 13, 2011
    Applicant: TDK CORPORATION
    Inventors: Yoshihiro Tsuchiya, Shinji Hara, Kiyoshi Noguchi, Migaku Takahashi, Masakiyo Tsunoda
  • Publication number: 20110007582
    Abstract: An information recording apparatus comprises a plurality of fine particles forming an array on a plane in close proximity of each other, each of the plural particles including a ferromagnetic metal, a light-emitting device for exciting a near-field light, and a photo-electric conversion element for detecting a near-field light traveled along the fine particles.
    Type: Application
    Filed: September 24, 2010
    Publication date: January 13, 2011
    Inventors: Migaku Takahashi, Masakiyo Tsunoda, Shin Saito, Tomoyuki Ogawa, Itaru Fujimura, Shigeyoshi Misawa, Toshiyuki Kawasaki
  • Patent number: 7862915
    Abstract: According to one embodiment, a multilayered underlayer including a first underlayer containing Cu aligned in a (111) plane and a second underlayer formed on the Cu underlayer and containing Cu and nitrogen as main components is formed.
    Type: Grant
    Filed: December 19, 2006
    Date of Patent: January 4, 2011
    Assignees: Tohoku University, Kabushiki Kaisha Toshiba, Showa Denko K.K.
    Inventors: Tomoyuki Maeda, Migaku Takahashi, Masahiro Oka
  • Patent number: 7826174
    Abstract: An information recording apparatus comprises a plurality of fine particles forming an array on a plane in close proximity of each other, each of the plural particles including a ferromagnetic metal, a light-emitting device for exciting a near-field light, and a photo-electric conversion element for detecting a near-field light traveled along the fine particles.
    Type: Grant
    Filed: March 30, 2007
    Date of Patent: November 2, 2010
    Assignees: Ricoh Company, Ltd., Tohoku University
    Inventors: Migaku Takahashi, Masakiyo Tsunoda, Shin Saito, Tomoyuki Ogawa, Itaru Fujimura, Shigeyoshi Misawa, Toshiyuki Kawasaki
  • Patent number: 7802920
    Abstract: A first and a second static-pressure gas bearings supporting a rod at two locations in the axial direction in the non-contact manner are provided, in which the first static-pressure gas bearing is fixedly supported by a bearing housing, while the second static-pressure gas bearing is supported capable of displacement through a movable support mechanism. And this movable support mechanism has an actuator and suppresses contact of the rod with the static-pressure gas bearings by displacing the shaft center of the second static-pressure gas bearing with respect to the first static-pressure gas bearing by this actuator according to a load acting on the rod.
    Type: Grant
    Filed: October 25, 2006
    Date of Patent: September 28, 2010
    Assignees: SMC Corporation, Tohoku University
    Inventors: Soichi Sato, Takashi Abe, Eiko Miyasato, Migaku Takahashi, Masakiyo Tsunoda
  • Publication number: 20100188772
    Abstract: There are provided a method for manufacturing a magnetic recording medium which is excellent in terms of both the recording and reproduction characteristics and the thermal fluctuation characteristics without reducing the density and hardness of the perpendicular magnetic layer; a magnetic recording medium; and a magnetic recording and reproducing apparatus with which an excellent recording density is achieved, wherein, in the method for manufacturing the magnetic recording medium, at least a portion of the perpendicular magnetic layer 4 is formed as a magnetic layer having a granular structure that contains Co as a major component and also contains an oxide of at least one nonmagnetic metal selected from the group consisting of Cr, Si, Ta, Al, Ti, W and Mg; a target for forming the perpendicular magnetic layer 4 by the sputtering process is prepared so as to include an oxide of Co and a compound of Co and at least one nonmagnetic metal selected from the group consisting of Cr, Si, Ta, Al, Ti, W and Mg, and t
    Type: Application
    Filed: January 22, 2010
    Publication date: July 29, 2010
    Applicants: SHOWA DENKO K.K., KABUSHIKI KAISHA TOSHIBA, TOHOKU UNIVERSITY
    Inventors: Shingo Sasaki, Shin Saito, Migaku Takahashi, Atsushi Hashimoto, Yuzo Sasaki, Gohei Kurokawa, Tomoyuki Maeda, Akihiko Takeo
  • Publication number: 20100173175
    Abstract: A magnetic recording medium is provided, which has at least one soft magnetic layer, at least one seed layer, at least one underlayer and at least one perpendicular magnetic recording layer, and is characterized in that the or each seed layer is comprised of a covalently bonded material. The covalently bonded material preferably predominantly comprises a nitride having a hexagonal crystal structure, more preferably, predominantly comprises aluminum nitride having a hexagonal wurtzite crystal structure. This magnetic recording medium is superior in recording and reproducing an information with high density.
    Type: Application
    Filed: June 6, 2008
    Publication date: July 8, 2010
    Applicants: SHOWA DENKO K.K., TOSHIBA CORPORATION, TOHOKU UNIVERSITY
    Inventors: Migaku Takahashi, Shin Saito, Tomoyuki Maeda, Akihiko Takeo, Yuzo Sasaki, Ryuji Sakaguchi
  • Publication number: 20100165510
    Abstract: A magnetic recording medium comprising a substrate, at least one soft magnetic underlayer formed on the substrate, a perpendicular magnetic recording layer formed on the soft magnetic underlayer, and a protective layer formed on the perpendicular magnetic recording layer, is provided wherein the perpendicular magnetic recording layer is comprised of a primary recording layer, a non-magnetic intermediate layer and an auxiliary layer; the primary recording layer comprises magnetic crystal grains and grain boundary portions surrounding the magnetic crystal grains, and has a perpendicular magnetic anisotropy; the auxiliary layer has a negative magneto crystalline anisotropy; and the non-magnetic intermediate layer is formed between the primary recording layer and the auxiliary layer and comprises at least one metal selected from Ru, Rh and Ir, or at least one alloy thereof.
    Type: Application
    Filed: May 21, 2008
    Publication date: July 1, 2010
    Inventors: Migaku Takahashi, Shin Saito, Tomoyuki Maeda, Akihiko Takeo, Yuzo Sasaki, Ryuji Sakaguchi
  • Patent number: 7687158
    Abstract: The invention provides a perpendicular magnetic recording medium in which the recording density is greatly increased with little deviation of the crystal structure. A perpendicular magnetic recording medium has at least a soft magnetic under layer, an orientation control layer, a perpendicular magnetic layer, and a protective layer, which are formed on a nonmagnetic substrate, the orientation control layer consisting of a plurality of layers including a seed layer and an intermediate layer from the substrate side. Preferably, the seed layer and the intermediate layer each have a hexagonal close-packed (hcp) structure, and the average grain size of the seed layer is between 8 nm and 20 nm. The main component of the seed layer is preferably Mg, and the main component of the intermediate layer is preferably Ru.
    Type: Grant
    Filed: October 28, 2005
    Date of Patent: March 30, 2010
    Assignees: Showa Denko K.K., Kabushiki Kaisha Toshiba
    Inventors: Migaku Takahashi, Masahiro Oka, Akira Kikitsu
  • Publication number: 20100039730
    Abstract: The present invention provides a magnetic recording medium which is capable of improving the perpendicular orientation of a perpendicular magnetic recording layer while maintaining a writing performance during recording and obtaining both an improvement in the perpendicular orientation and fine magnetic crystal particles with a uniform diameter, and which enables information to be recorded or reproduced at high density, a method of manufacturing the same, and a magnetic recording/reproducing apparatus. A magnetic recording medium 10 according to the present invention includes at least a soft magnetic underlayer 2, an orientation control layer 3, a magnetic recording layer 4, and a protective layer 5 formed on a non-magnetic substrate 1. The orientation control layer 3 has a seed layer 6 and an intermediate layer 7. The seed layer 6 is made of a Cu—Ti alloy that has a face-centered cubic structure and includes Cu as a main component.
    Type: Application
    Filed: August 17, 2009
    Publication date: February 18, 2010
    Applicants: SHOWA DENKO K. K., KABUSHIKI KAISHA TOSHIBA, TOHOKU UNIVERSITY
    Inventors: Shinichi ISHIBASHI, Migaku TAKAHASHI, Shin SAITO, Yuzo SASAKI, Atsushi HASHIMOTO, Gohei KUROKAWA, Tomoyuki MAEDA, Akihiko TAKEO
  • Publication number: 20100033873
    Abstract: In a perpendicular magnetic recording medium in which at least a soft magnetic underlayer, an orientation control layer, a magnetic recording layer and a protective layer are formed on a non-magnetic substrate in order from the bottom, the orientation control layer has a laminated structure of two or more layers including an intermediate layer and a seed layer which is disposed closer to the non-magnetic substrate than the intermediate layer. The seed layer includes two or more kinds of elements having a face-centered cubic structure, has face-centered cubic (111) plane crystals oriented in a direction perpendicular to a substrate surface, and has a pseudo-hexagonal structure.
    Type: Application
    Filed: August 5, 2009
    Publication date: February 11, 2010
    Applicants: SHOWA DENKO K. K., KABUSHIKI KAISHA TOSHIBA, TOHOKU UNIVERSITY
    Inventors: Shinichi ISHIBASHI, Migaku Takahashi, Shin Saito, Yuzo Sasaki, Atsushi Hashimoto, Gohei Kurokawa, Tomoyuki Maeda, Akihiko Takeo
  • Patent number: 7618708
    Abstract: An organic layer capable of forming surface areas having an adsorption property different from that of a periphery due to the chemical change of a surface functional group is formed on a board. The surface of the organic layer is patterned and oxidized by a scanning probe microscope to form an array pattern in which small sections for adsorbing nanoparticles are arranged. Then, nanoparticle dispersed solution is applied to the organic layer having the array pattern or the organic layer is dipped in the nanoparticle dispersed solution to form a particle layer on the organic layer. At this time, the nanoparticles in the nanoparticle dispersed solution are respectively fixed only onto the small sections. Therefore, a nanoparticle array on which groups of nanoparticles are arranged in an array can be obtained. Thus, the nanoparticle array on which the groups of the nanoscale particles are arranged on the board is efficiently formed.
    Type: Grant
    Filed: August 26, 2004
    Date of Patent: November 17, 2009
    Assignee: Sony Corporation
    Inventors: Mikihisa Mizuno, Yuichi Sasaki, Andrew Chak Chung Yu, Makoto Inoue, Migaku Takahashi, Kazuyuki Tohji, Jeyaderan Balachandran
  • Publication number: 20090231755
    Abstract: The invention provides a magnetic recording medium, and a magnetic recording and reproducing apparatus. The magnetic recording medium includes a substrate 11, an under layer 12 formed on the substrate 11, a magnetic recording layer 13 formed on the under layer 12, and a protective layer 14 formed on the magnetic recording layer 13. The magnetic recording layer 13 is composed of a primary recording layer 14 and a secondary recording layer 15 which are mutually exchange-coupled. The primary recording layer 14 has magnetic grains and a nonmagnetic material that surrounds the magnetic grains, and has a perpendicular magnetic anisotropy. The secondary recording layer 15 is made of a material having a negative crystal magnetic anisotropy and its easy plane of the magnetization is a plane of the medium.
    Type: Application
    Filed: June 9, 2006
    Publication date: September 17, 2009
    Inventors: Migaku Takahashi, Masahiro Oka, Akira Kikitsu