Patents by Inventor Takahiro Onoue

Takahiro Onoue 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: 9047903
    Abstract: An object of the present invention is to provide a perpendicular magnetic recording medium in which each space between crystal grains of a first magnetic recording layer is so designed as to allow the layer to also have a function as a continuous layer, and a method of manufacturing a perpendicular magnetic recording medium. In a perpendicular magnetic recording medium 100 according to the present invention, a first magnetic recording layer 122a and a second magnetic recording layer 122b are ferromagnetic layers each having a granular structure in which a grain boundary part made of a non-magnetic substance is formed between crystal grains each grown in a column shape and, in the first magnetic recording layer 122a, an intergranular distance defined by an average of shortest distances between grain boundary parts each between a crystal grain and its adjacent crystal grain is equal to or shorter than 1 nm.
    Type: Grant
    Filed: March 26, 2009
    Date of Patent: June 2, 2015
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventor: Takahiro Onoue
  • Publication number: 20140370424
    Abstract: An object of the present invention is to provide a substrate with a multilayer reflective film and the like used in the manufacturing of a reflective mask blank for EUV lithography which is to be subjected to dry etching with a Cl-based gas, wherein in the substrate with the multilayer reflective film, the loss of protective films by the dry etching and subsequent wet cleaning is very limited. The present invention is a substrate with a multilayer reflective film used in the manufacturing of a reflective mask blank for EUV lithography, comprising a substrate, a multilayer reflective film disposed on the substrate to reflect EUV light, and a protective film disposed on the multilayer reflective film to protect the multilayer reflective film, the protective film includes an alloy containing at least two metals, the alloy being an all-proportional solid solution.
    Type: Application
    Filed: March 21, 2013
    Publication date: December 18, 2014
    Applicant: HOYA CORPORATION
    Inventors: Takahiro Onoue, Toshihiko Orihara
  • Patent number: 8895163
    Abstract: In a perpendicular magnetic recording medium having, over a substrate, a magnetic recording layer, an underlayer made of Ru or a Ru compound and provided below the magnetic recording layer, a pre-underlayer made of a nonmagnetic crystalline material, and a soft magnetic layer provided below the pre-underlayer, when the difference between the highest point and the lowest point of unevenness of the interface between the soft magnetic layer and the pre-underlayer, derived by a cross-sectional TEM image, is given as an interface roughness (nm) and the distance between the soft magnetic layer and the magnetic recording layer, excluding the soft magnetic layer and the magnetic recording layer, is given as a SUL-MAG distance (nm), interface roughness (nm)?0.4 (nm) and interface roughness×SUL-MAG distance (nm)?12 (nm) are satisfied.
    Type: Grant
    Filed: March 31, 2010
    Date of Patent: November 25, 2014
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventor: Takahiro Onoue
  • Patent number: 8883249
    Abstract: By improving sliding durability while ensuring a high SNR, an improvement in reliability and a further increase in recording density are to be achieved.
    Type: Grant
    Filed: December 28, 2010
    Date of Patent: November 11, 2014
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Toshiaki Tachibana, Takahiro Onoue, Keiichi Kajita
  • Patent number: 8871368
    Abstract: A perpendicular magnetic recording medium with SNR improved by reducing noise due to an auxiliary recording layer so that a higher recording density can be achieved. The perpendicular magnetic recording medium 100 includes a base, at least a magnetic recording layer 122 having a granular structure in which a non-magnetic grain boundary portion is formed between crystal particles grown in a columnar shape; a non-magnetic split layer 124 disposed on the magnetic recording layer 122 and containing Ru and oxygen; and an auxiliary recording layer 126 that is disposed on the split layer 124 and that is magnetically approximately continuous in an in-plane direction of a main surface of the base 110.
    Type: Grant
    Filed: September 16, 2009
    Date of Patent: October 28, 2014
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Takahiro Onoue, Teiichiro Umezawa, Toshiaki Tachibana, Masafumi Ishiyama
  • Patent number: 8859118
    Abstract: An object is to provide a perpendicular magnetic recording medium including a ground layer that prevents corrosion, while achieving a primary object of promoting finer magnetic particles of a magnetic recording layer and isolation of these magnetic particles. The structure of a perpendicular magnetic recording medium 100 according to the present invention includes, at least on a base 110: a magnetic recording layer 122 on which a signal is recorded; a ground layer 118 provided below the magnetic recording layer; a non-magnetic layer 116 for controlling crystal orientation of the ground layer; and a soft magnetic layer 114 provided below the non-magnetic layer. The ground layer 118 is configured to have three layers including, in an order from bottom, a first ground layer 118a and a second ground layer 118b that contain ruthenium, and a third ground layer 118c that contains a metal.
    Type: Grant
    Filed: January 10, 2011
    Date of Patent: October 14, 2014
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Toshiaki Tachibana, Takahiro Onoue
  • Publication number: 20140044992
    Abstract: A perpendicular magnetic recording medium 100 having a magnetic recording layer 122, wherein a particle diameter of crystal grains in layer 122 improves a SNR while a high coercive force is maintained. There also is at least a ground layer 118, a first magnetic recording layer 122a, and a second magnetic recording layer 122b in this order on a disk base 110. The first layer 122a and the second layer 122b are ferromagnetic layers, each having a granular structure in which a grain boundary part made of a non-magnetic substance is formed between crystal grains each grown in a columnar shape, and A<B when an average particle diameter of the crystal grains in the first magnetic recording layer 122a is taken as A nm and an average particle diameter of the crystal grains in the second magnetic recording layer 122b is taken as B nm.
    Type: Application
    Filed: October 10, 2013
    Publication date: February 13, 2014
    Applicant: WD Media (Singapore) Pte. Ltd.
    Inventor: Takahiro ONOUE
  • Patent number: 8623528
    Abstract: An object of the present invention is to provide a method of manufacturing a perpendicular magnetic recording medium (100) in which both of a coercive force Hc and reliability can be achieved at a higher level even with heating at the time of forming a medium protective layer (126) and to provide the perpendicular magnetic recording medium (100).
    Type: Grant
    Filed: March 25, 2009
    Date of Patent: January 7, 2014
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Teiichiro Umezawa, Masafumi Ishiyama, Tokichiro Sato, Kenji Ayama, Takahiro Onoue, Junichi Horikawa
  • Patent number: 8603649
    Abstract: A perpendicular magnetic recording medium includes a magnetic recording layer 22 having a granular structure composed of crystal grains containing cobalt (Co) and grown in a columnar shape and a grain boundary portion comprising a nonmagnetic substance and formed between the crystal grains, and a continuous layer 24 of a thin film magnetically continuous in a film plane direction. The continuous layer 24 includes a plurality of layers 24a and 24b containing cobalt, chromium (Cr), and platinum (Pt). Among the layers, the layer 24a nearer to the magnetic recording layer has a greater chromium content.
    Type: Grant
    Filed: October 6, 2008
    Date of Patent: December 10, 2013
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventor: Takahiro Onoue
  • Patent number: 8592061
    Abstract: In order to provide a magnetic recording medium having excellent electromagnetic conversion characteristics, a magnetic recording medium (10) is provided with a substrate (12), and a magnetic recording layer (20) formed on the substrate (12). The magnetic recording layer (20) is provided with a granular layer (32), i.e., a magnetic layer, including magnetic grains and a nonmagnetic material surrounding the magnetic grains in a section parallel to the main surface of the substrate. The ratio of the long diameter to the short diameter of each magnetic grain contained in the granular layer (32) is calculated in the section. In the histogram of such ratio, a half width at half maximum of the histogram is 0.6 or less and the variance of grain diameters of the magnetic grains in the section is 20% or less of the average grain diameter of the magnetic grains.
    Type: Grant
    Filed: September 26, 2007
    Date of Patent: November 26, 2013
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Takahiro Onoue, Akira Shimada
  • Patent number: 8580410
    Abstract: An object of the present invention is to provide a perpendicular magnetic recording medium 100 including a magnetic recording layer 122, the medium in which a particle diameter of crystal grains in the magnetic recording layer 122 of a two-layer structure is so designed as to improve an SNR while a high coercive force is maintained.
    Type: Grant
    Filed: March 26, 2009
    Date of Patent: November 12, 2013
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventor: Takahiro Onoue
  • Publication number: 20130230647
    Abstract: A perpendicular magnetic recording medium comprises a magnetic recording layer that records a signal, an underlayer formed of Ru or Ru compound below the magnetic recording layer, a non-magnetic layer formed of a non-magnetic material below the underlayer to control crystal orientation of the underlayer, a soft magnetic layer provided below the non-magnetic layer, and a substrate on which the magnetic recording layer, the underlayer, the non-magnetic layer, and the soft magnetic layer are formed. The non-magnetic layer comprises a first non-magnetic layer formed above the soft magnetic layer and a second non-magnetic layer formed above the first non-magnetic layer. The first non-magnetic layer is formed of amorphous Ni compound while the second non-magnetic layer is formed of crystalline Ni or crystalline Ni compound.
    Type: Application
    Filed: April 23, 2013
    Publication date: September 5, 2013
    Applicant: WD Media (Singapore) PTE.LTD.
    Inventors: Takahiro ONOUE, Tokichiro Sato, Takenori Kajiwara
  • Patent number: 8431258
    Abstract: A perpendicular magnetic recording medium comprises a magnetic recording layer that records a signal, an underlayer formed of Ru or Ru compound below the magnetic recording layer, a non-magnetic layer formed of a non-magnetic material below the underlayer to control crystal orientation of the underlayer, a soft magnetic layer provided below the non-magnetic layer, and a substrate on which the magnetic recording layer, the underlayer, the non-magnetic layer, and the soft magnetic layer are formed. The non-magnetic layer comprises a first non-magnetic layer formed above the soft magnetic layer and a second non-magnetic layer formed above the first non-magnetic layer. The first non-magnetic layer is formed of amorphous Ni compound while the second non-magnetic layer is formed of crystalline Ni or crystalline Ni compound.
    Type: Grant
    Filed: March 30, 2010
    Date of Patent: April 30, 2013
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Takahiro Onoue, Tokichiro Sato, Takenori Kajiwara
  • Patent number: 8404370
    Abstract: A perpendicular magnetic recording medium 100 has, over a substrate, at least a magnetic recording layer 122 with a granular structure in which nonmagnetic grain boundaries are formed between magnetic grains continuously grown into a columnar shape. The magnetic grains of the magnetic recording layer 122 contain Co, Cr, and Pt. The magnetic recording layer 122 contains at least one oxide selected from a group A including SiO2, TiO2, and Cr2O3, at least one oxide selected from a group B consisting of oxides each having a larger Gibbs free energy ?G than the group A, and a reducing agent adapted to reduce the oxides of the group B.
    Type: Grant
    Filed: March 31, 2010
    Date of Patent: March 26, 2013
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Tokichiro Sato, Takahiro Onoue, Takenori Kajiwara
  • Patent number: 8076013
    Abstract: A magnetic recording medium (10) has a substrate (12) and a perpendicular magnetic recording layer (30) formed over the substrate (12). The perpendicular magnetic recording layer (30) has a granular layer (20) in which a magnetic signal is recorded and a continuous film layer (24) magnetically coupled to the granular layer (20). The continuous film layer (24) has hard magnetic portions (204) formed in positions corresponding to the recording regions where magnetic signals are recorded in the granular layer (20) and magnetic shield portions (202) formed between the hard magnetic portions (204), each having a magnetization curve whose slope is larger than those of the hard magnetic portions in the region where the applied magnetic filed is zero when the magnetization curve is measured, and each having a residual magnetic polarization smaller than those in the hard magnetic portions.
    Type: Grant
    Filed: February 13, 2008
    Date of Patent: December 13, 2011
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Yoshiaki Sonobe, Takahiro Onoue, Koichi Wago
  • Publication number: 20110223446
    Abstract: An object of the present invention is to provide a perpendicular magnetic recording medium the SNR of which is further improved while a high coercive force Hc is secured so that a higher recoding density can be achieved.
    Type: Application
    Filed: September 16, 2009
    Publication date: September 15, 2011
    Applicant: WD MEDIA (SINGAPORE) PTE. LTD.
    Inventors: Takahiro Onoue, Teiichiro Umezawa
  • Publication number: 20110212346
    Abstract: An object of the present invention is to provide a perpendicular magnetic recording medium the SNR of which is improved by reducing noise thought to be due to an auxiliary recording layer so that a higher recording density can be achieved, and a method of manufacturing the same. In order to achieve the above object, a representative configuration of a perpendicular magnetic recording medium 100 according to the present invention includes, on a base, at least a magnetic recording layer 122 having a granular structure in which a non-magnetic grain boundary portion is formed between crystal particles grown in a columnar shape; a non-magnetic split layer 124 disposed on the magnetic recording layer 122 and containing Ru and oxygen; and an auxiliary recording layer 126 that is disposed on the split layer 124 and that is magnetically approximately continuous in an in-plane direction of a main surface of the base 110.
    Type: Application
    Filed: September 16, 2009
    Publication date: September 1, 2011
    Applicant: WD MEDIA (SINGAPORE) PTE. LTD.
    Inventors: Takahiro Onoue, Teiichiro Umezawa, Toshiaki Tachibana, Masafumi Ishiyama
  • Publication number: 20110206947
    Abstract: By improving sliding durability while ensuring a high SNR, an improvement in reliability and a further increase in recording density are to be achieved.
    Type: Application
    Filed: December 28, 2010
    Publication date: August 25, 2011
    Applicant: WD MEDIA (SINGAPORE) PTE. LTD.
    Inventors: Toshiaki TACHIBANA, Takahiro Onoue, Keiichi Kajita
  • Publication number: 20110171495
    Abstract: An object is to provide a perpendicular magnetic recording medium including a ground layer that prevents corrosion, while achieving a primary object of promoting finer magnetic particles of a magnetic recording layer and isolation of these magnetic particles. The structure of a perpendicular magnetic recording medium 100 according to the present invention includes, at least on a base 110: a magnetic recording layer 122 on which a signal is recorded; a ground layer 118 provided below the magnetic recording layer; a non-magnetic layer 116 for controlling crystal orientation of the ground layer; and a soft magnetic layer 114 provided below the non-magnetic layer. The ground layer 118 is configured to have three layers including, in an order from bottom, a first ground layer 118a and a second ground layer 118b that contain ruthenium, and a third ground layer 118c that contains a metal.
    Type: Application
    Filed: January 10, 2011
    Publication date: July 14, 2011
    Applicant: WD MEDIA (SINGAPORE) PTE. LTD.
    Inventors: Toshiaki TACHIBANA, Takahiro ONOUE
  • Publication number: 20110111262
    Abstract: An object of the present invention is to provide a method of manufacturing a perpendicular magnetic recording medium (100) in which both of a coercive force Hc and reliability can be achieved at a higher level even with heating at the time of forming a medium protective layer (126) and to provide the perpendicular magnetic recording medium (100).
    Type: Application
    Filed: March 25, 2009
    Publication date: May 12, 2011
    Applicant: WD Media (Singapore) Pte. Ltd.
    Inventors: Teiichiro Umezawa, Masafumi Ishiyama, Tokichiro Sato, Kenji Ayama, Takahiro Onoue, Junichi Horikawa