Disk Patents (Class 360/135)
  • Patent number: 8861116
    Abstract: In one embodiment, a method includes spiral writing a DC pattern onto a magnetic disk medium using a writer of a magnetic head while moving the magnetic head in a direction about parallel to a radial direction of the magnetic disk medium while rotating the magnetic disk medium, reading the magnetic disk medium while moving the magnetic head in the direction about parallel to the radial direction of the magnetic disk medium while rotating the magnetic disk medium, and calculating a track pitch interval between data tracks of the magnetic disk medium based on the reading of the magnetic disk medium. In another embodiment, a magnetic disk medium includes a DC spiral pattern in a radial region further outward and/or a radial region further inward than a radial region where data is recorded.
    Type: Grant
    Filed: August 2, 2011
    Date of Patent: October 14, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Mao Nishiyama, Masafumi Mochizuki, Kyo Akagi, Shuji Nishida, Kazunari Usui
  • Patent number: 8858809
    Abstract: A manufacturing method of a magnetic recording medium includes steps of forming a magnetic recording layer, a first mask layer, a second mask layer containing silicon as primary component, a strip layer, a third mask layer, and a resist layer, a step of patterning the resist layer to provide a pattern, steps of transferring the pattern to the third mask layer, to the strip layer, and to the second mask layer, a step of removing the strip layer by wet etching and of stripping the third mask layer and the resist layer above the magnetic recording layer, steps of transferring the pattern to the first mask layer and to the magnetic recording layer, and a step of stripping the first mask layer remaining on the magnetic recording layer.
    Type: Grant
    Filed: September 7, 2012
    Date of Patent: October 14, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Akira Watanabe, Kaori Kimura, Kazutaka Takizawa, Takeshi Iwasaki, Tsuyoshi Onitsuka, Akihiko Takeo
  • Patent number: 8848307
    Abstract: An apparatus includes a magnetic recording layer and a thermally active material adjacent to and/or embedded in the magnetic recording layer, wherein the thermally active material has a thermal property that changes when the temperature of the thermally active material changes, or undergoes a phase transition in a predetermined temperature range, to reduce a peak temperature or increase a thermal gradient of a heated portion of the magnetic recording layer.
    Type: Grant
    Filed: February 2, 2012
    Date of Patent: September 30, 2014
    Assignee: Seagate Technology LLC
    Inventors: Michael Allen Seigler, William Challener
  • Patent number: 8842392
    Abstract: According to one embodiment, a magnetic recording medium includes: a data area on which a plurality of first magnetic dots are arranged at predetermined positions to record information; a servo area on which a plurality of second magnetic dots for specifying the positions of said plurality of first magnetic dots are arranged at predetermined positions; and servo frames configured so that a frequency of said servo frames is 2N per circumference of said medium having a radius, that said servo frames are radially discontinuous, and that said servo frame and a space-area, on which no servo frames exist, are alternately radially arranged at a cycle W.
    Type: Grant
    Filed: February 13, 2012
    Date of Patent: September 23, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazuto Kashiwagi, Makoto Asakura, Haruhiko Izumi, Masatoshi Sakurai
  • Patent number: 8830630
    Abstract: A magnetic recording medium may include a stacked structure of orientation control, lower recording, intermediate, and upper recording layers. The lower recording layer has a coercivity higher than that of the upper recording layer. The lower recording layer includes a first layer with a granular structure that includes magnetic particles including Co, Cr, and Pt, and an oxide covering a periphery of the magnetic particles, and a second layer with a non-granular structure that includes magnetic particles including Co, Cr, and Pt. The lower recording layer includes columnar crystals continuous with crystal particles forming the orientation control layer in a stacking direction of the stacked structure.
    Type: Grant
    Filed: May 24, 2013
    Date of Patent: September 9, 2014
    Assignee: Showa Denko K.K.
    Inventors: Hideaki Takahoshi, Daisuke Amiya, Hiroshi Sakai
  • Patent number: 8830631
    Abstract: A recording media design having discrete track recording structure where the trenches between tracks are filled with a soft magnetic material is provided. The soft magnetic material provides a low magnetic impedance path to the soft underlayer such that fringe fields from the write head are conducted to the soft underlayer without having a negative effect such as adjacent track erasure. A method of manufacturing the media includes a nano-imprint step and ion milling out the data layer to create the trenches. A B2O3 material allows the data layer to be ion milled out without redeposition bridging the B2O3 layer thus preventing lift off of the mask. The trenches are then filled by ion deposition with the layers of ferromagnetic material separated by an anti-ferromagnetic coupling that causes the flux to be conducted to the soft underlayer and remnant flux to rotate within the island and not into adjacent tracks.
    Type: Grant
    Filed: June 11, 2013
    Date of Patent: September 9, 2014
    Assignee: Seagate Technology LLC
    Inventors: Mourad Benakli, Michael Mallary
  • Patent number: 8824248
    Abstract: An aspect of the present invention relates to glass for a magnetic recording medium substrate, which includes essential components in the form of SiO2, Li2O, Na2O, and one or more alkaline earth metal oxides selected from the group consisting of MgO, CaO, SrO, and BaO, wherein a molar ratio of a content of MgO to a combined content of MgO, CaO, SrO, and BaO (MgO/(MgO+CaO+SrO+BaO)) is equal to or greater than 0.80, and which has a Young's modulus of equal to or greater than 80 GPa, and a glass transition temperature of equal to or greater than 620° C.
    Type: Grant
    Filed: May 9, 2013
    Date of Patent: September 2, 2014
    Assignee: Hoya Corporation
    Inventors: Naomi Matsumoto, Kazuaki Hashimoto
  • Patent number: 8822047
    Abstract: A method for making a master mold that is used in the nanoimprinting process to make patterned-media disks with patterned data islands uses guided self-assembly of a block copolymer into its components. Conventional or e-beam lithography is used to first form a pattern of generally radial stripes on a substrate, with the stripes being grouped into annular zones or bands. A block copolymer material is then deposited on the pattern, resulting in guided self-assembly of the block copolymer into its components to multiply the generally radial stripes into generally radial lines. Various methods, including conventional lithography, guided self-assembly of a second block copolymer, and e-beam lithography, are then used to form concentric rings over the generally radial lines. After etching and resist removal, the master mold has a pattern of either pillars or holes, depending on the method used.
    Type: Grant
    Filed: June 2, 2011
    Date of Patent: September 2, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Elizabeth Ann Dobisz, Ricardo Ruiz
  • Patent number: 8817422
    Abstract: A magnetic storage medium is formed of magnetic nanoparticles that are encapsulated within nanotubes (e.g., carbon nanotubes).
    Type: Grant
    Filed: April 16, 2013
    Date of Patent: August 26, 2014
    Assignee: Sigma Pro Ltd. LLC
    Inventor: Tyson York Winarski
  • Patent number: 8804285
    Abstract: A magnetic recording medium may include an orientation control layer, a lower recording layer, an intermediate layer, and an upper recording layer that are stacked. The lower recording layer may have a coercivity higher than that of the upper recording layer, and the intermediate layer may include a layer including a magnetic material and having a saturation magnetization of 50 emu/cc or higher. The upper recording layer may include columnar crystals continuous with crystal particles forming the intermediate layer in a direction in which the layers are stacked.
    Type: Grant
    Filed: May 15, 2013
    Date of Patent: August 12, 2014
    Assignee: Showa Denko K.K.
    Inventors: Hideaki Takahoshi, Daisuke Amiya, Hiroshi Sakai
  • Publication number: 20140218824
    Abstract: The present disclosure relates to a magnetic medium that includes a substrate and a bit patterned magnetic layer applied to the substrate. The bit-patterned magnetic layer includes islands and each island includes a first magnetic material having a first magnetic anisotropy and that has a top surface, a bottom surface, and a peripheral surface. Each island also includes a second magnetic material covering the peripheral surface of the first magnetic material and having a second magnetic anisotropy that is higher than the first magnetic anisotropy. In one embodiment, the first magnetic material may comprise a nucleation domain in a centrally located surface portion of the magnetic islands and/or the second magnetic material may comprise an outer shell on the peripheral surface of the islands.
    Type: Application
    Filed: February 6, 2013
    Publication date: August 7, 2014
    Applicant: HGST NETHERLANDS B.V.
    Inventors: Michael Grobis, Dan S. Kercher, Kurt A. Rubin
  • Patent number: 8795859
    Abstract: A magnetic recording medium includes, in a main surface of a glass substrate on which a magnetic recording layer is formed, a plurality of annular first thermally-conductive regions having a larger thermal conductivity than the glass substrate that are provided concentrically with the glass substrate. The first thermally-conductive regions are each provided so that it extends across a plurality of tracks. The first thermally-conductive region has a radial width larger than a depth, from the main surface, of the first thermally-conductive region.
    Type: Grant
    Filed: June 22, 2011
    Date of Patent: August 5, 2014
    Assignee: Hoya Corporation
    Inventors: Naoyuki Fukumoto, Hiroshi Hatano
  • Patent number: 8790799
    Abstract: A method for forming a glass substrate comprises the steps of forming a glass blank with opposing substantially planar surfaces and at least one edge, coating the glass blank in silica-alumina nanoparticles, the silica-alumina nanoparticles comprising an inner core of silica with an outer shell of alumina, annealing the coated glass blank to form a conformal coating of silica-alumina around the glass blank, and polishing the coated glass blank to remove the conformal coating of silica-alumina from the opposing substantially planar surfaces thereof.
    Type: Grant
    Filed: June 22, 2012
    Date of Patent: July 29, 2014
    Assignee: WD Media, LLC
    Inventor: Shoji Suzuki
  • Patent number: 8792201
    Abstract: Processes include aligning a disc with a template at a location so that the pattern from the template is transferred to the disc in a relative orientation. The relative orientation provides that when the disc with the transferred pattern is finally assembled into a hard disc drive, an inner diameter of the spindle hole of the disc may be abutted against an outer diameter of the disc drive spindle, and the data-containing patterns on the discs will be aligned concentrically with a center of the disc drive spindle. While the data-containing patterns are aligned concentrically with the disc drive spindle, the substrate itself is allowed to be non-concentric.
    Type: Grant
    Filed: December 2, 2009
    Date of Patent: July 29, 2014
    Assignee: Seagate Technology LLC
    Inventors: Gennady Gauzner, David S. Kuo, Justin Jia-Jen Hwu, Li-Ping Wang, Zhaoning Yu, Kim Yang Lee
  • Publication number: 20140204486
    Abstract: According to various embodiments, a recording medium may be provided. The recording medium may include a dedicated servo layer configured to provide servo information. The dedicated servo layer may include a plurality of tracks. A first track may include a first servo signal. The first servo signal may include first servo bursts of a pre-determined frequency. A second track adjacent to the first track may include a second servo signal. The second servo signal may include second servo bursts of the pre-determined frequency.
    Type: Application
    Filed: July 19, 2013
    Publication date: July 24, 2014
    Inventors: Jingliang Zhang, Anmin Kong, Songhua Zhang, Zhimin Yuan, Linlin Thi
  • Patent number: 8786971
    Abstract: According to one embodiment, there is provided a magnetic recording apparatus including a head slider including read and write elements, and a magnetic recording medium including magnetically recordable recording tracks with a width L1, a wide land track with a width L2 larger than the width L1 of the recording track, and non-recording sections with a width G1 each provided between adjacent recording tracks. The width L1 of the recording track is smaller than a bottom read width BRW of the read and write elements, and the width L2 of the wide land track is larger than the bottom read width BRW of the read and write elements.
    Type: Grant
    Filed: February 7, 2014
    Date of Patent: July 22, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masatoshi Sakurai, Kazuto Kashiwagi, Naoki Tagami
  • Patent number: 8787130
    Abstract: Systems and methods for providing heat assisted magnetic recording (HAMR) media configured to couple energy from a near field transducer (NFT) are provided. One such method includes providing a magnetic recording layer including an L10 ordered FePt or an L10 ordered CoPt, selecting a plurality of preselected parameters for a coupling layer, the preselected parameters including a material, a preselected deposition temperature, and a preselected thickness, and depositing the coupling layer directly on the magnetic recording layer using the preselected parameters such that the coupling layer has an extinction coefficient greater than 0.1.
    Type: Grant
    Filed: June 29, 2013
    Date of Patent: July 22, 2014
    Assignee: WD Media, LLC
    Inventors: Hua Yuan, Bogdan F. Valcu, Antony Ajan, B. Ramamurthy Acharya, Alexander S. Chernyshov, Paul C. Dorsey
  • Patent number: 8785009
    Abstract: A magnetic recording medium includes a plurality of recording tracks magnetically continuous with respect to a recording direction and arranged intermittently in a track width direction, a plurality of recording dots intermittently formed in the recording tracks in the recording direction and a plurality of space dots alternately formed in the recording track with the recording dots in the recording direction and having a magnetic moment per unit area smaller than a magnetic moment per unit area of the recording dots.
    Type: Grant
    Filed: March 3, 2009
    Date of Patent: July 22, 2014
    Assignee: Fujitsu Limited
    Inventor: Hiroto Takeshita
  • Patent number: 8786985
    Abstract: Storage architecture for bit patterned media uses both erase band and shingled magnetic recording. A hard disk drive may comprise a disk having bit patterned media with a plurality of data tracks arrayed in architecture pages having at least one of erase band mode (EBM), shingled mode (SM) and unallocated space. An actuator has a head for writing data to the data tracks of the bit patterned media. A control system monitors, reallocates and reconfigures the architecture pages from EBM, SM or unallocated space to a different one of EBM, SM or unallocated space to enhance performance of the hard disk drive.
    Type: Grant
    Filed: April 1, 2013
    Date of Patent: July 22, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Michael K. Grobis, Hans J. Richter
  • Patent number: 8785011
    Abstract: According to one aspect of the present invention, provided is glass for use in substrate for information recording medium, which comprises, denoted as molar percentages, a total of 70 to 85 percent of SiO2 and Al2O3, where SiO2 content is equal to or greater than 50 percent and Al2O3 content is equal to or greater than 3 percent; a total of equal to or greater than 10 percent of Li2O, Na2O and K2O; a total of 1 to 6 percent of CaO and MgO, where CaO content is greater than MgO content; a total of greater than 0 percent but equal to or lower than 4 percent of ZrO2, HfO2, Nb2O5, Ta2O5, La2O3 Y2O3 and TiO2; with the molar ratio of the total content of Li2O, Na2O and K2O to the total content of SiO2, Al2O3, ZrO2, HfO2, Nb2O5, Ta2O5, La2O3, Y2O3 and TiO2 ((Li2O+Na2O+K2O)/(SiO2+Al2O3+ZrO2+HfO2+Nb2O5+Ta2O5+La2O3+Y2O3+TiO2)) being equal to or less than 0.28.
    Type: Grant
    Filed: September 6, 2012
    Date of Patent: July 22, 2014
    Assignee: Hoya Corporation
    Inventors: Kazuo Tachiwana, Yoichi Hachitani, Xuelu Zou, Mikio Ikenishi, Kinobu Osakabe
  • Publication number: 20140192435
    Abstract: A memory system includes a storage medium having tracks arranged on the storage medium. The tracks include data track portions configured to store data. The tracks have a data track width and offset correction portions having a width that is greater than the data track width of the associated data track. Each offset correction portion stores one or both of positional offset correction values and timing offset correction values. The positional offset correction values are configured to correct for errors that occur in cross track positioning relative to the medium and the timing offset correction values are configured to correct for errors that occur in down track timing relative to the medium.
    Type: Application
    Filed: January 4, 2013
    Publication date: July 10, 2014
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventor: Bruce Douglas Buch
  • Patent number: 8767350
    Abstract: In one embodiment, a method for forming a magnetic recording medium includes forming a protective layer above recording regions of a patterned magnetic recording layer and separating regions between the recording regions, wherein the protective layer forms on sides of the recording regions and partially fills the separating regions, and forming a filler layer on the protective layer, wherein the filler layer completely fills the separating regions, wherein the filler layer has an uneven upper surface. In another embodiment, a medium includes a patterned magnetic recording layer, a protective layer above the patterned magnetic recording layer and on sides of the patterned magnetic recording layer, and a filler layer positioned between the patterned magnetic recording layer in separating regions, wherein DLC of the filler layer is a lower density than DLC of the protective layer. Other systems and methods are described according to more embodiments.
    Type: Grant
    Filed: December 6, 2010
    Date of Patent: July 1, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Hiroshi Yakushiji, Toshinori Ono, Tatsuya Hinoue
  • Patent number: 8760980
    Abstract: Apparatus for recording data and method for making the same. In accordance with some embodiments, a magnetic recording layer is adapted to store data along perpendicular magnetic domains. A protective overcoat layer is formed on the magnetic recording layer to substantially protect the magnetic recording layer from environmental effects. The protective overcoat layer is made of carbon intermixed with at least one transition metal, such as but not limited to chromium.
    Type: Grant
    Filed: February 26, 2013
    Date of Patent: June 24, 2014
    Assignee: Seagate Technology LLC
    Inventors: Lihong Zhang, Samuel Gan
  • Patent number: 8748017
    Abstract: According to one embodiment, a bit patterned medium includes a substrate, and a magnetic recording layer disposed above the substrate and including patterns of protrusions. Each of the protrusions contains a plurality of crystal grains. An average distance between the crystal grains is 0.5 to 3.0 nm in each of the protrusions. The protrusions include first protrusions each having a length of 1 ?m or more in a radial direction of the medium and second protrusions each having a length in the radial direction shorter than the length of the first protrusion in the radial direction. Each of the first protrusions has a nucleation field Hn for magnetization reversal and a coercive force Hc satisfying the inequalities, Hn?1.5 kOe and 0.5 kOe?Hc?Hn?1.5 kOe.
    Type: Grant
    Filed: July 1, 2011
    Date of Patent: June 10, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masatoshi Sakurai, Yousuke Isowaki, Soichi Oikawa
  • Patent number: 8736993
    Abstract: Approaches are provided for a hard-disk drive (HDD) and techniques for using multiple LUNs per HDD where each LUN is mapped to a head/disk interface. In one example, a HDD generates multiple LUNs and assigns each to a single head, such that data written by a first head is only associated to a first LUN, and so forth.
    Type: Grant
    Filed: June 28, 2012
    Date of Patent: May 27, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Zvonimir Z. Bandic, Cyril Guyot
  • Patent number: 8734967
    Abstract: The shape and number of surface defects are controlled so that the occurrence of failure is suppressed in an HDD device in which a magnetic head with a very small flying height, such as a DFH head, is mounted. A magnetic disk substrate is characterized in that when laser light with a wavelength of 405 nm and a laser power of 25 mW is irradiated with a spot size of 5 ?m and scattered light from the substrate is detected, the number of defects detected to have a size of 0.1 ?m to not more than 0.3 ?m is less than 50 per 24 cm2 and, with respect to the defects, there is no defect in which, in a bearing curve obtained by a bearing curve plot method using an atomic force microscope, a portion from an apex of the defect to 45% thereof is located in an area of defect height higher than a virtual line connecting from the apex of the defect to 45% thereof.
    Type: Grant
    Filed: June 29, 2009
    Date of Patent: May 27, 2014
    Assignee: Hoya Corporation
    Inventors: Kouji Kitsunai, Hiroshi Takeda, Yukari Senda
  • Patent number: 8728638
    Abstract: Provided are a magnetic disk substrate that can be adapted to a reduction in flying height of a head in an HDD and to an increase in rotational speed therein, and a method of manufacturing such a substrate. In an annular glass substrate for a magnetic recording medium, a main surface (12) of the glass substrate is uniformly inclined from an inner peripheral end (13) to an outer peripheral end (14) and has an isotropic shape with respect to an axis passing through the center of the glass substrate. That is, it is rotationally symmetric with respect to an arbitrary angle rotation about the axis passing through the center of the glass substrate.
    Type: Grant
    Filed: June 29, 2009
    Date of Patent: May 20, 2014
    Assignee: Hoya Corporation
    Inventors: Hideki Isono, Hiroshi Tsuchiya
  • Patent number: 8715841
    Abstract: A glass substrate for information recording medium, said glass substrate being composed of an aluminosilicate glass containing 60-75% by mass of SiO2, 5-18% by mass of Al2O3, 3-10% by mass of Li2O, 3-15% by mass of Na2O and 0.5-8% by mass of ZrO2 relative to the entire glass components. The glass substrate for information recording medium contains neither As (arsenic) nor Sb (antimony), while containing at least one substance selected from the group consisting of SO3 (sulfurous acid), F (fluorine), Cl (chlorine), Br (bromine) and I (iodine), as a refining agent. The molar ratio of the total amount of the refining agent to the amount of ZrO2 is within the range of 0.05-0.50.
    Type: Grant
    Filed: July 3, 2009
    Date of Patent: May 6, 2014
    Inventor: Hideki Kawai
  • Patent number: 8717710
    Abstract: In one embodiment, a magnetic recording medium includes a magnetic recording layer including a magnetic material characterized by having convex and concave portions, the convex portions acting as magnetic regions, a nonmagnetic material positioned within each concave portion of the magnetic material which act as nonmagnetic regions that separate the magnetic regions, an organic material layer which exhibits a corrosion-inhibiting characteristic with respect to cobalt or cobalt alloy positioned on a nonmagnetic region side of each concave portion, and an oxide layer and/or hydroxide layer positioned adjacent the organic material layer on a magnetic region side of each concave portion of the magnetic material. In another embodiment, the magnetic recording medium may be a patterned recording layer having a protective film, and the oxide layer and/or hydroxide layer may be positioned at least in defect portions of the protective film.
    Type: Grant
    Filed: May 8, 2012
    Date of Patent: May 6, 2014
    Assignee: HGST Netherlands, B.V.
    Inventors: Qing Dai, Bruno Marchon, Katsumi Mabuchi, Mina Amo
  • Patent number: 8709620
    Abstract: A magnetic recording medium includes a magnetic recording layer. The magnetic recording layer includes a first magnetic layer formed as a pattern portion that is a data portion in a servo region, a second magnetic layer formed as a non-pattern portion that is magnetized to be antiparallel with a magnetization direction of the first magnetic layer and of which coercive force is lower than a coercive force of the first magnetic layer, and a nonmagnetic layer formed between the first magnetic layer and the second magnetic layer.
    Type: Grant
    Filed: April 20, 2010
    Date of Patent: April 29, 2014
    Assignee: Showa Denko K.K.
    Inventor: Yuuki Yoshida
  • Patent number: 8711519
    Abstract: A shallow trench discrete track media structure is fabricated by etching a magnetic recording layer to provide a plurality of discrete magnetic data tracks separated by shallow trenches. Each shallow trench has a trench floor formed at a depth in the magnetic recording layer that is less than the thickness of the magnetic recording layer. Exposed regions of the magnetic recording layer beneath the trench floor are reacted with reactive plasma to diminish the magnetic moment of the exposed regions.
    Type: Grant
    Filed: April 15, 2013
    Date of Patent: April 29, 2014
    Assignee: Seagate Technology LLC
    Inventors: Zhaohui Fan, David Kuo
  • Patent number: 8705208
    Abstract: According to one embodiment, a PMRM includes a substrate, a soft magnetic underlayer above the substrate, an underlayer above the soft magnetic underlayer, an oxide-containing magnetic layer above the underlayer, and a ferromagnetic layer above the magnetic layer having no oxides. The underlayer controls orientation and segregation of the magnetic layer. The oxide-containing magnetic layer comprises at least two or more magnetic layers, a Cr concentration of the magnetic layer adjacent to the ferromagnetic metal layer is between about 23 at. % and about 32 at. %, and a difference between the Cr concentration of the magnetic layer adjacent to the ferromagnetic metal layer and a magnetic layer having a lowest Cr concentration among the at least three magnetic layers is less than about 25 at. %, the magnetic layer with a lowest Cr concentration has a granular structure, and a nucleation field is greater than about 159.2 kA/m.
    Type: Grant
    Filed: June 30, 2010
    Date of Patent: April 22, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Hiroyuki Nakagawa, Reiko Arai, Ichiro Tamai, Kiwamu Tanahashi
  • Patent number: 8705207
    Abstract: A thermal-assist magnetic recording medium is provided which can accomplish a surface recording density of 1 Tbit/inch2. The thermal-assist magnetic recording medium includes: a substrate; a plurality of underlying layers formed on the substrate; a first magnetic layer formed on the underlying layers; a coupling control layer formed on the first magnetic layer and formed of a ferromagnetic alloy; and a second magnetic layer formed on the coupling control layer. Here, Curie temperatures of the first magnetic layer and the second magnetic layer are higher than the Curie temperature of the coupling control layer, an anisotropy magnetic field of the first magnetic layer is greater than the anisotropy magnetic field of the second magnetic layer, and a saturation magnetic field has a minimum value at a temperature of 350° C. or lower.
    Type: Grant
    Filed: November 30, 2009
    Date of Patent: April 22, 2014
    Assignee: Showa Denko K.K.
    Inventors: Tetsuya Kanbe, Yuzo Sasaki, Atsushi Hashimoto
  • Patent number: 8699185
    Abstract: A disk drive is disclosed wherein a plurality of zones are defined on first and second disk surfaces, wherein each zone comprises a plurality of data tracks. Data is written to the data tracks of a first plurality of the zones on the first and second disk surfaces in an interleaved manner, in a first radial direction, and in a shingled manner. Data is written to the data tracks of a second plurality of the zones on the first and second disk surfaces in an interleaved manner, in a second radial direction opposite the first radial direction, and in a shingled manner. At least one guard band is defined at a boundary between a first zone and a second zone in the second plurality of zones on the first disk surface, wherein the guard band comprises at least one unused data track.
    Type: Grant
    Filed: December 10, 2012
    Date of Patent: April 15, 2014
    Assignee: Western Digital Technologies, Inc.
    Inventors: Joo Peng Teh, James N. Malina, Joe C. Lee, Muhammad Nur Syukri Ahmad Shukor
  • Patent number: 8683699
    Abstract: A production method of a disk drive device includes: an assembling process of assembling a subassembly by incorporating at least a bearing unit in a hub in a clean room; a pouring process of pouring a lubricant in the bearing unit; a cleaning-liquid discharging process of discharging a cleaning liquid to the hub; a cleaning-liquid intake process of taking in the cleaning liquid discharged to the hub; and a sealing process of sealing the subassembly in a seal-material.
    Type: Grant
    Filed: December 7, 2010
    Date of Patent: April 1, 2014
    Assignee: Samsung Electro-Mechanics Japan Advanced Technology Co., Ltd.
    Inventor: Mitsuhiro Aono
  • Patent number: 8687309
    Abstract: This invention provides a magnetic recording medium excellent in terms of corrosion resistance. The magnetic recording medium comprises a magnetic recording layer, a protective layer and a lubricant layer provided on a nonmagnetic substrate, and the lubricant layer comprises a compound having a heterocyclic ring.
    Type: Grant
    Filed: July 8, 2011
    Date of Patent: April 1, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Katsumi Mabuchi, Kyoko Honbo, Mina Amo
  • Patent number: 8687323
    Abstract: A magnetic media disk has a substrate; a recording magnetic media on the substrate; and an overcoat on the recording magnetic media, the overcoat comprising a Si-based layer on the recording magnetic media, and a Ti-based layer on the Si-based layer. The magnetic media disk may be rotatably mounted to an enclosure in a hard disk drive.
    Type: Grant
    Filed: October 12, 2011
    Date of Patent: April 1, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Bruno Marchon, Daryl J. Pocker, Franck D. Rose, Qi-Fan Xiao
  • Patent number: 8681454
    Abstract: According to one embodiment, a method of manufacturing a patterned medium includes depositing a magnetic recording layer and applying an ultraviolet curable resin on both surfaces of a medium substrate, pressing a first resin stamper and a second resin stamper each including patterns of recesses and protrusions, corresponding to a patterned medium, against both surfaces of the medium substrate in such a manner that a direction from a center of the medium substrate toward a center of the first resin stamper is off-oriented from a direction from the center of the medium substrate toward a center of the second resin stamper to imprint the patterns of recesses and protrusions on the ultraviolet curable resin, and irradiating the ultraviolet curable resin with an ultraviolet ray through each of the first and second resin stampers to cure the ultraviolet curable resin.
    Type: Grant
    Filed: March 19, 2012
    Date of Patent: March 25, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Akira Kikitsu, Yoshiyuki Kamata, Masatoshi Sakurai
  • Patent number: 8673465
    Abstract: A magnetic recording medium includes a recording layer having a granular structure in which magnetic particles are dispersed within a non-magnetic base, and a non-magnetic material embedded in grooves of patterns formed on the recording layer. The magnetic particles have an inverted truncated cone shape with a diameter larger in an upper region of the recording layer than in a lower region of the recording layer.
    Type: Grant
    Filed: December 17, 2009
    Date of Patent: March 18, 2014
    Assignee: Showa Denko K.K.
    Inventor: Koji Matsumoto
  • Patent number: 8665549
    Abstract: A magnetic data storage system having a magnetic disk having burst patterns for providing a position error signal (PES) wherein each magnetic burst pattern is offset from an adjacent burst pattern by ¼ track pitch. All of the magnetic bits of the burst patterns can be unipolar magnetized, and the bits of each burst pattern can be aligned with one another in radial and circumferential direction. The magnetic media can be a bit patterned media wherein the magnetic bits of the burst patterns are magnetically isolated portions separated by non-magnetic spaces or non-magnetic material.
    Type: Grant
    Filed: September 29, 2011
    Date of Patent: March 4, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Thomas R. Albrecht, Toshiki Hirano, Tetsuo Semba, Xiaotian Sun
  • Patent number: 8652659
    Abstract: A glass substrate for information recording medium, said glass substrate being composed of an aluminosilicate glass containing 60-75% by mass of SiO2, 5-18% by mass of Al2O3, 3-10% by mass of Li2O, 3-15% by mass of Na2O and 0.5-8% by mass of ZrO2 relative to the entire glass components. The glass substrate for information recording medium contains neither As (arsenic) nor Sb (antimony), while containing at least one substance selected from the group consisting of SO3 (sulfurous acid), F (fluorine), Cl (chlorine), Br (bromine) and I (iodine), as a refining agent. The molar ratio of the total amount of the refining agent to the amount of Al2O3 is within the range of 0.02-0.20.
    Type: Grant
    Filed: July 3, 2009
    Date of Patent: February 18, 2014
    Assignee: Konica Minolta Opto, Inc.
    Inventor: Hideki Kawai
  • Patent number: 8652660
    Abstract: An aspect of the present invention relates to a glass substrate for a magnetic recording medium, which is comprised of glass with a glass transition temperature of equal to or greater than 600° C., an average coefficient of linear expansion at 100 to 300° C. of equal to or greater than 70×10?7/° C., a Young's modulus of equal to or greater than 81 GPa, a specific modulus of elasticity of equal to or greater than 30 MNm/kg, and a fracture toughness value of equal to or greater than 0.9 MPa·m1/2.
    Type: Grant
    Filed: December 20, 2011
    Date of Patent: February 18, 2014
    Assignee: Hoya Corporation
    Inventors: Hideki Isono, Kinobu Osakabe, Katsuyuki Iwata, Mikio Ikenishi, Naomi Matsumoto
  • Patent number: 8634155
    Abstract: The invention provides a magnetic disk that solves (1) a problem of cross-talk that cannot be solved even by an existing thermally assisted recording method or a discrete method (DTM or the like), (2) a problem of surface flatness, which an existing embedding type DTM or the like has, and (3) a problem of a difference in thermal expansion coefficient between materials when a thermally assisted method is applied to the DTM, and that (4) does not necessitate a special medium structure, and is excellent in a surface flatness and economically and functionally high in realizability. A DTM manufactured by ion implantation is excellent in the surface flatness, and can solve the cross-talk problem by conducting the thermally assisted recording at a temperature between a Curie temperature (Tcn) of a portion where ions are implanted (non-recording region) and a Curie temperature (Tcr) of a portion where ions are not implanted (recording region).
    Type: Grant
    Filed: March 29, 2011
    Date of Patent: January 21, 2014
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Junichi Yasumori, Yoshiaki Sonobe
  • Patent number: 8634153
    Abstract: According to one embodiment, a magnetic recording medium includes a substrate, an auxiliary layer formed on the substrate, and at least one perpendicular magnetic recording layer formed on the auxiliary layer. The perpendicular magnetic recording layer includes a magnetic dot pattern. The perpendicular magnetic recording layer is made of an alloy material containing one element selected from iron and cobalt, and one element selected from platinum and palladium. This alloy material has the L10 structure, and is (001)-oriented. The auxiliary layer includes a dot-like first region covered with the magnetic dot pattern, and a second region not covered with the magnetic dot pattern. The first region is made of one metal selected from (100)-oriented nickel and (100)-oriented iron. The second region contains an oxide of the metal used in the first region.
    Type: Grant
    Filed: January 16, 2012
    Date of Patent: January 21, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tomoyuki Maeda, Yousuke Isowaki, Akira Watanabe
  • Publication number: 20140019680
    Abstract: In various embodiments, a data storage system may be provided. The data storage system may include a storage. The storage may include a first portion and a second portion. The data storage system may further include a determination circuit configured to determine whether to write data to the first portion or to the second portion. The data storage system may also include a control circuit configured to control writing the data to the first portion in a log structured manner.
    Type: Application
    Filed: July 16, 2013
    Publication date: January 16, 2014
    Inventors: Chao Jin, Weiya Xi, Khai Leong Yong, Zhi Yong Ching
  • Publication number: 20140011053
    Abstract: A perpendicular magnetic recording medium adapted for high recording density and high data recording rate comprises a non-magnetic substrate having at least one surface with a layer stack formed thereon, the layer stack including a perpendicular recording layer containing a plurality of columnar-shaped magnetic grains extending perpendicularly to the substrate surface for a length, with a first end distal the surface and a second end proximal the surface, wherein each of the magnetic grains has: (1) a gradient of perpendicular magnetic anisotropy field Hk extending along its length between the first end and second ends; and (2) predetermined local exchange coupling strengths along the length.
    Type: Application
    Filed: August 6, 2013
    Publication date: January 9, 2014
    Applicant: Seagate Technology LLC
    Inventors: Shaoping Li, Kaizhong Gao, Lei Wang, Wenzhong Zhu, Xiaobin Wang
  • 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: 8623530
    Abstract: A glass substrate for a magnetic disk, wherein, in regions with respect to two places arbitrarily selected on a surface of the glass substrate on its central portion side relative to its outer peripheral end, a surface shape with a shape wavelength in a band of 60 to 500 ?m is extracted from surface shapes in each of the regions and, assuming that a root mean square roughness Rq of the surface shape is given as a microwaviness Rq, the difference between the microwavinesses Rq of the regions is 0.02 nm or less or the difference between standard deviations of the microwavinesses Rq of the regions is 0.04 nm or less.
    Type: Grant
    Filed: July 6, 2012
    Date of Patent: January 7, 2014
    Assignee: Hoya Corporation
    Inventors: Kouji Kitsunai, Takashi Maeda
  • Patent number: 8625236
    Abstract: According to one embodiment, a patterned medium is disclosed herein. The patterned medium includes a patterned layer, a stop layer, and a fill layer. The patterned layer includes plurality of grooves. The stop layer is positioned on the patterned layer. The stop layer is at least partially positioned within the plurality of grooves and a portion of the stop layer may be positioned on walls of the grooves of the patterned layer. The fill layer is at least partially positioned within the grooves between portions of the stop layer. The stop layer substantially separates the fill layer from the patterned layer.
    Type: Grant
    Filed: March 30, 2012
    Date of Patent: January 7, 2014
    Assignee: HGST Netherlands B.V.
    Inventor: Kurt A. Rubin
  • Publication number: 20140002929
    Abstract: A manufacturing method of a magnetic recording medium includes follows: forming a magnetic recording layer on a substrate; forming an under layer and a metal release layer that forms an alloy with the under layer on the magnetic recording layer in this order and forming an alloyed release layer by alloying the under layer and the metal release layer; forming a mask layer on the alloyed release layer; forming a resist layer on the mask layer; providing a protrusion-recess pattern by patterning the resist layer; transferring the protrusion-recess pattern to the mask layer; transferring the protrusion-recess pattern to the alloyed release layer; transferring the protrusion-recess pattern to the magnetic recording layer; dissolving the alloyed release layer by using a stripping solution and removing a layer formed on the alloyed release layer from an upper side of the magnetic recording layer.
    Type: Application
    Filed: October 24, 2012
    Publication date: January 2, 2014
    Inventors: Kazutaka TAKIZAWA, Akira Watanabe, Kaori Kimura, Takeshi Iwasaki, Akihiko Takeo