Patents Assigned to Hoya Magnetics Singapore Pte. Ltd.
  • Publication number: 20100323221
    Abstract: Provided is a magnetic disk (10) for a magnetic recording, which comprises a magnetic layer (4) for a magnetic recording, a protecting layer (5) formed over the magnetic layer (4) for protecting the magnetic layer (4), and a lubricating layer (6) formed over the protecting layer (5). The protecting layer (5) is a layer composed substantially of carbon, hydrogen and nitrogen. The atomic ratio (N/C) of nitrogen and carbon, which was calculated from the spectral intensities of N1s and C1s detected for a detection angle of 7 degrees of photoelectrons by an angularly resolved X-ray photoelectron spectroscopy, is 0.15 to 0.25. This constitution of the protecting layer (5) is excellent in wear resistance and sliding characteristics even for a film thickness of 3 nm or less and provides a magnetic disk which can avoid a high fly write trouble or the like.
    Type: Application
    Filed: September 19, 2008
    Publication date: December 23, 2010
    Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE. LTD.
    Inventor: Masafumi Ishiyama
  • Publication number: 20100323220
    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: Application
    Filed: October 6, 2008
    Publication date: December 23, 2010
    Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE. LTD.
    Inventor: Takahiro Onoue
  • Publication number: 20100279151
    Abstract: A perpendicular magnetic recording medium includes a substrate, a soft magnetic layer, a pre-underlayer, an underlayer, and a main recording layer serving as a magnetic recording layer. The pre-underlayer contains seed crystal grains that serve as a base for crystal grains of the underlayer, and an addition substance that is added between the seed crystal grains and composed of an element having an atomic radius smaller than that of an element forming the seed crystal grains.
    Type: Application
    Filed: October 14, 2008
    Publication date: November 4, 2010
    Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE. LTD.
    Inventors: Kazuaki Sakamoto, Kong Kim, Takahiro Onoue, Masafumi Ishiyama, Teiichiro Umezawa, Kenji Ayama
  • Publication number: 20100255348
    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: Application
    Filed: March 31, 2010
    Publication date: October 7, 2010
    Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE. LTD.
    Inventors: Tokichiro SATO, Takahiro ONOUE, Takenori KAJIWARA
  • Publication number: 20100247965
    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: Application
    Filed: March 31, 2010
    Publication date: September 30, 2010
    Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE. LTD.
    Inventor: Takahiro Onoue
  • Publication number: 20100246064
    Abstract: In a magnetic disk has at least a magnetic layer, a carbon-based protective layer, and a lubricating layer formed in this order over a substrate, the lubricating layer contains a lubricant compound including a compound which has a perfluoropolyether main chain in a structure thereof, an aromatic group located at a position except each end of a molecule thereof, and a polar group at each end of the molecule.
    Type: Application
    Filed: March 26, 2010
    Publication date: September 30, 2010
    Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE. LTD.
    Inventors: Kae ITOH, Katsushi HAMAKUBO, Koichi SHIMOKAWA
  • Publication number: 20100247964
    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: March 30, 2010
    Publication date: September 30, 2010
    Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE. LTD.
    Inventors: Takahiro ONOUE, Tokichiro Sato, Takenori Kajiwara
  • Publication number: 20100247963
    Abstract: A perpendicular magnetic recording medium is used for information recording of a perpendicular magnetic recording type. The perpendicular magnetic recording medium includes a substrate, a soft magnetic layer, an underlayer, and a magnetic layer having a multilayered structure including a plurality of magnetic layers. The soft magnetic layer, the underlayer, and the magnetic layer are formed on the substrate. At least one of the magnetic layers includes CoPt magnetic grains containing oxide. The oxide includes at least one material selected from the group consisting of SiO2, TiO2, Cr2O3, Ta2O5, WO3, CoO, and Co3O4.
    Type: Application
    Filed: March 29, 2010
    Publication date: September 30, 2010
    Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE. LTD.
    Inventors: Kong KIM, Hi SHIN, Tomoko SEKI, Satoshi ISHII
  • Publication number: 20100215992
    Abstract: A magnetic recording medium used for perpendicular magnetic recording, the magnetic recording medium comprising: a substrate having a first surface and a second surface opposite to the first surface; a magnetic recording medium constituent layer formed on the first surface of the substrate, the magnetic recording medium constituent layer including at least a magnetic recording layer; a non-magnetic metal film formed on the second surface of the substrate; and a carbon-based protective film formed on the non-magnetic metal film.
    Type: Application
    Filed: February 22, 2010
    Publication date: August 26, 2010
    Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE. LTD.
    Inventors: Junichi HORIKAWA, Kenji AYAMA, Masafumi ISHIYAMA, Toshikatsu YAMAGUCHI, Yusuke SETO
  • Publication number: 20100209740
    Abstract: [Object] The present invention provides a perpendicular magnetic recording medium that can reduce noise by further size reduction and isolation of magnetic grains in a magnetic recording layer and can increase the recording density by improvement of the SNR. [Means for Solution] A typical configuration of a perpendicular magnetic recording medium according to the present invention is a perpendicular magnetic recording medium 100 having a magnetic recording layer 122 with a granular structure in which non-magnetic grain boundary portions are formed between magnetic grains that have grown continuously in a columnar shape, wherein the grain boundary portions contain a plurality of kinds of oxides.
    Type: Application
    Filed: September 26, 2008
    Publication date: August 19, 2010
    Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE., LTD.
    Inventors: Kenji Ayama, Tokichiro Sato, Teiichiro Umezawa, Masafumi Ishiyama, Junichi Horikawa
  • Publication number: 20100209601
    Abstract: On manufacturing a magnetic disk having at least a magnetic layer (60), a protective layer (70), and a lubricating layer (80) formed in this order over a substrate (10), the lubricating layer is formed by using a coating solution in which a perfluoropolyether compound having a perfluoropolyether main chain and a hydroxyl group in a structure thereof is dispersed and dissolved in a fluorine-based solvent having a boiling point of 90° C. or more.
    Type: Application
    Filed: February 18, 2010
    Publication date: August 19, 2010
    Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE. LTD.
    Inventors: Koichi SHIMOKAWA, Katsushi HAMAKUBO, Kae ITOH
  • Publication number: 20100196740
    Abstract: A perpendicular magnetic recording medium of the invention is characterized by having, on a disk substrate 110, a soft magnetic layer 14, a magnetic recording layer 22, a continuous layer 24 magnetically continuous in the in-plane direction of the substrate, a blocking layer 25 for blocking shock imposed on the continuous layer, and a medium protective layer 28 containing carbon formed on the blocking layer.
    Type: Application
    Filed: September 24, 2008
    Publication date: August 5, 2010
    Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE LTD
    Inventors: Kenji Ayama, Tokichiro Sato, Teiichiro Umezawa, Masafumi Ishiyama
  • Publication number: 20100196619
    Abstract: In a magnetic disk having a magnetic layer, a protection layer, and a lubrication layer formed on a substrate in this order, a surface free energy ?S of a surface of the magnetic disk derived by an extended Fowkes equation is greater than 0 and no greater than 24 mN/m. ?Sd (dispersion force component of surface free energy) forming the surface free energy ?S is greater than 0 and no greater than 17 mN/m, ?Sp (dipole component of surface free energy) forming the surface free energy ?S is greater than 0 and no greater than 1 mN/m, and ?Sh (hydrogen bonding force component of surface free energy) forming the surface free energy ?S is greater than 0 and no greater than 6 mN/m.
    Type: Application
    Filed: April 12, 2010
    Publication date: August 5, 2010
    Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE. LTD.
    Inventor: Masafumi ISHIYAMA
  • Patent number: 7736768
    Abstract: A magnetic disk comprises a magnetic layer and a protective layer sequentially formed on a disk-shaped substrate and has a principal surface to which data is recorded, and a side surface portion both of which are coated with the protective layer. The protective layer on the side surface portion is thinner than the protective layer on the principal surface. Preferably, the side surface portion includes a side wall surface, and a chamfered surface lying between the side wall surface and the principal surface, and at least the protective layer on the chamfered surface is thinner than the protective layer on the principal surface.
    Type: Grant
    Filed: September 29, 2005
    Date of Patent: June 15, 2010
    Assignees: Hoya Corporation, Hoya Magnetics Singapore Pte. Ltd.
    Inventor: Masafumi Ishiyama
  • Patent number: 7722968
    Abstract: In a magnetic disk having a magnetic layer, a protection layer, and a lubrication layer formed on a substrate in this order, a surface free energy ?S of a surface of the magnetic disk derived by an extended Fowkes equation is greater than 0 and no greater than 24 mN/m. ?Sd (dispersion force component of surface free energy) forming the surface free energy ?S is greater than 0 and no greater than 17 mN/m, ?Sp (dipole component of surface free energy) forming the surface free energy ?S is greater than 0 and no greater than 1 mN/m, and ?Sh (hydrogen bonding force component of surface free energy) forming the surface free energy ?S is greater than 0 and no greater than 6 mN/m.
    Type: Grant
    Filed: February 7, 2005
    Date of Patent: May 25, 2010
    Assignee: Hoya Magnetics Singapore Pte. Ltd.
    Inventor: Masafumi Ishiyama
  • Publication number: 20100119878
    Abstract: Provided is a magnetic recording medium which maintains high S/N ratio and coercive force (Hc) and has high recording density, even with fine magnetic particles, by further improving crystal orientation of a magnetic recording layer. The magnetic recording medium is provided with an orientation control layer (16), a nonmagnetic under layer (18), and a magnetic recording layer (22) on a substrate. The orientation control layer (16) has an fcc structure and a (111) plane parallel to the substrate. The under layer (18) has an hcp structure and a (0001) plane parallel to the substrate. An atomic distance of the (111) plane of the orientation control layer (16) is ?0.2 ? to +0.15 ? to a lattice spacing of the under layer (18).
    Type: Application
    Filed: March 28, 2008
    Publication date: May 13, 2010
    Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE. LTD.
    Inventors: Teiichiro Umezawa, Masafumi Ishiyama, Kenji Ayama, Tokichiro Sato
  • Publication number: 20100112379
    Abstract: A vertical magnetic recording disc (100) includes a base (10), a magnetic recording layer (22), and a medium protection layer (26). The magnetic recording layer (22) is a ferromagnetic layer having a granular structure where a granular portion is formed. The medium protection layer (26) contains nitrogen (N) atoms and carbon (C) atoms with a number ratio (N/C) in a range from 0.050 to 0.150. In a Raman spectrum obtained by exciting the medium protection layer (26) by argon ion laser light of wavelength 514.5 nm, from which a fluorescence is removed, the peak ratio Dh/Gh is in a range from 0.70 to 0.95, when a D peak Dh appearing in the vicinity of 1350 cm?1 is separated from G peak Gh appearing in the vicinity of 1520 cm?1 by the Gauss function.
    Type: Application
    Filed: March 28, 2008
    Publication date: May 6, 2010
    Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE. LTD.
    Inventors: Teiichiro Umezawa, Masafumi Ishiyama, Kenji Ayama, Tokichiro Sato
  • Patent number: 7695833
    Abstract: In a method of evaluating surface tension of a solid body surface, selection is made of at least three liquid samples having different surface tensions, and contact angles between the respective liquid samples and the solid body surface are measured. Thereby, a correlation between cosines (Y) of the contact angles and surface tensions (X) of the liquid samples is derived as a logarithmic function. Surface tension of the solid body surface is evaluated by the use of a value of X that is calculated by substituting 1 for Y in the correlation. When evaluated by the foregoing evaluation method, a magnetic disk has a surface where the value of X, when 1 is substituted for Y, is greater than 0 and no greater than 17 mN/m.
    Type: Grant
    Filed: January 16, 2007
    Date of Patent: April 13, 2010
    Assignees: Hoya Corporation, Hoya Magnetics Singapore Pte. Ltd.
    Inventor: Masafumi Ishiyama
  • Publication number: 20100039724
    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: Application
    Filed: September 26, 2007
    Publication date: February 18, 2010
    Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE. LTD.
    Inventors: Takahiro Onoue, Akira Shimada
  • Publication number: 20090287335
    Abstract: A processing data managing system includes: a processing device 11 (such as a sputtering device for manufacturing a magnetic disc) for repeating the same process for each cycle; a sampling unit 30 for collecting raw data on a processing condition in the processing device (such as a discharge condition); a calculation unit 100 for receiving the raw data, calculating the raw data according to a predetermined rule, and processing it as summary data expressing a characteristic point for each cycle (characteristic value: for example, average value, maximum value, minimum value, standard deviation, discharge time, and the like); a data storage unit 40 for storing the processed summary data in storage means; and a display/output unit 50 for chart-displaying the summary data stored in the storage means.
    Type: Application
    Filed: March 30, 2007
    Publication date: November 19, 2009
    Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE. LTD.
    Inventor: Takumi Kobayashi