Patents Examined by Stevan Resan
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Patent number: 6916531Abstract: Embodiments relate to lubricants disposed over magnetic storage media, such as rotatable thin film magnetic discs. One embodiment comprises a lubricant compound of a fluoropolyether chain having one or more carbonyl-imide pairs. For example, the carbonyl-imide pair may be located at one end, both ends, and/or in the middle of the fluoropolyether chain.Type: GrantFiled: April 30, 2004Date of Patent: July 12, 2005Assignee: Seagate Technology LLCInventors: Jianwei Liu, Michael Joseph Stirniman, Jing Gui
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Patent number: 6913780Abstract: The present invention provides a method for inspecting deposition characteristics of a deposit on the surface of a protective film predominantly containing carbon of a magnetic recording medium, which medium includes a disk and the protective film formed on the disk, the disk including a non-magnetic substrate, a non-magnetic undercoat layer, and a magnetic layer, the layers being formed on the substrate, wherein the method includes comparing a predetermined threshold with the extraction amount of an inspection gas component and/or a compound component formed so as to contain the inspection gas component, the gas component and/or the compound component being extracted with an inspection solvent after the magnetic recording medium is allowed to stand in an atmosphere of the inspection gas component; a process for producing a magnetic recording medium in which the extraction amount is equal to or greater than the threshold, the extraction amount being obtained through the inspection method; and a magnetic recorType: GrantFiled: July 31, 2001Date of Patent: July 5, 2005Assignee: Showa Denko K.K.Inventors: Junya Kato, Mikio Suzuki
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Patent number: 6913818Abstract: A magnetic recording medium comprising a non-magnetic support and a magnetic layer containing a binder and a ferromagnetic metal powder dispersed in the binder, wherein the binder contains a polyurethane resin obtained from a polyester polyol, a chain extender, and an organic diisocyanate, and the magnetic layer has a product ? of coercive force Hc (kA/m) in an in-plane, longitudinal direction and magnetic flux Øm (T?m) in a range of from 400 to 800.Type: GrantFiled: June 4, 2004Date of Patent: July 5, 2005Assignee: Fuji Photo Film Co., Ltd.Inventors: Satoshi Matsubaguchi, Hiroaki Takano
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Patent number: 6911272Abstract: A magnetic recording medium comprising: a support; an undercoating layer; and a thin ferromagnetic metal layer, in this order, wherein the undercoating layer comprises a reaction product of a mixture comprising a compound represented by the following formula (I): Ra—Si—Xb wherein R represents an organic group having 1 to 40 carbon atoms which may contain a functional group; X represents a hydrolyzable group; a is an integer of 0 to 3; and a+b is 4, and an oligomer of a compound represented by the formula (I) which comprises at least two siloxane bonds and has a viscosity of 4 to 100 mPa·sec, the mixture comprising at least a compound represented by the formula (I) wherein b is 2 or greater.Type: GrantFiled: April 1, 2003Date of Patent: June 28, 2005Assignee: Fuji Photo Film Co., Ltd.Inventor: Kazutoshi Katayama
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Patent number: 6908659Abstract: A magnetic recording medium for use in reproduction with an MR head, which comprises: a non-magnetic substrate; a non-magnetic layer including a binder resin having dispersed therein a non-magnetic powder on the non-magnetic substrate; and a magnetic layer on the non-magnetic layer, wherein the magnetic layer is obtained by applying a magnetic coating material on the applied, dried and cured non-magnetic layer, the magnetic layer includes a metal magnetic powder with a mean major axis length of from 0.03 to 0.08 ?m, and a saturation magnetization ?s of from 100 to 130 Am2/kg, and the center line mean roughness Ra of the magnetic layer surface is 5 nm or less.Type: GrantFiled: October 14, 2003Date of Patent: June 21, 2005Assignee: TDK CorporationInventor: Hideki Sasaki
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Patent number: 6905753Abstract: Provided is a particulate magnetic recording medium having good durability and a high C/N ratio in high-density magnetic recording (particularly when employing an MR head for reproduction). A magnetic recording medium which comprises a lower layer comprising a nonmagnetic powder and a binder and a magnetic layer comprising a ferromagnetic powder, an abrasive and a binder provided in this order on a nonmagnetic flexible support. The magnetic layer has a mean thickness d ranging from 0.01 to 0.1 ?m, the ferromagnetic powder contained in the magnetic layer is an acicular ferromagnetic alloy powder having the mean major axis length equal to or less than 0.1 ?m and the saturation magnetization ?s equal to or less than 120 A·m2/kg, and the number of abrasive protrusions ranging in height from 5 to 10 nm on the surface of the magnetic layer ranges from 15 to 25/225 ?m2.Type: GrantFiled: August 30, 2001Date of Patent: June 14, 2005Assignee: Fuji Photo Film Co., Ltd.Inventors: Masahiko Mori, Kiyomi Ejiri
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Patent number: 6899943Abstract: A method of manufacturing a glass substrate for a magnetic disk. The method includes the step of scrub-etching the glass substrate using a pad in the presence of an acid treatment solution. As the acid treatment solution, hydrofluoric acid is used in a range of 0.01 to 1 wt %. The scrub-etching step is performed at temperatures ranging from 5 to 60° C. for 1 second to 300 seconds. The method produces a substrate that is substantially free of asperity.Type: GrantFiled: February 14, 2003Date of Patent: May 31, 2005Assignee: Hoya CorporationInventors: Hiroshi Ikeda, Yoshihiro Matsuno, Takeo Watanabe
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Patent number: 6896959Abstract: A dual-layer magnetic recording medium including a non-magnetic substrate having a front side and a back side, a lower support layer formed over the front side and a magnetic upper recording layer formed over the lower layer, wherein the magnetic layer contains a volume concentration of at least about 35% of a magnetic metallic particulate pigment having a coercivity of at least about 2000 Oersteds (Oe), and a binder system for the pigment. The magnetic recording medium exhibits an orientation ratio greater than 2.0, a pulsewidth (PW50) value of less than about 500 nm, and a remanence-thickness product, Mr*t, of less than about 5.0 memu/cm2.Type: GrantFiled: May 19, 2003Date of Patent: May 24, 2005Assignee: Imation Corp.Inventor: Bruce H. Edwards
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Patent number: 6896957Abstract: Theres is disclosed a magnetic recording medium which includes a magnetizable layer thereon, wherein said magnetizable layer comprises a plurality of ferri- or ferromagnetic particles each having a largest dimension no greater than 100 nm, and each of which particles represents a separate ferromagnetic domain.Type: GrantFiled: November 17, 1997Date of Patent: May 24, 2005Assignee: NanoMagnetics, Ltd.Inventors: Eric Leigh Mayes, Malvin Nicolas Tyler
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Patent number: 6893702Abstract: The present invention relates to a substrate for a magnetic recording medium that ensures a floating height on a magnetic head. This substrate is made of a sintered body provided with pores having a diameter in the range of 0.05 ?m to 2.0 ?m extending across 5% to 50% of the surface area of the substrate.Type: GrantFiled: January 20, 2004Date of Patent: May 17, 2005Assignee: Fujitsu LimitedInventor: Shinichi Takahashi
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Patent number: 6893701Abstract: A magnetic disk medium having on a support a magnetic layer containing hexagonal ferrite powder dispersed in a binder, with the support having a thickness of 20 ?m to 80 ?m and the magnetic disk medium having an inside diameter X of 2 mm to 10 mm, an outside diameter Y of 20 mm to 50 mm, an X/Y ratio satisfying the relation 0.05?X/Y?0.20 and a curl quantity of 1 mm or below, which is suitable for use in small-diameter portable computer equipment and video recorders, and besides, can attain a recording capacity of at least several hundred megabytes.Type: GrantFiled: November 14, 2003Date of Patent: May 17, 2005Assignee: Fuji Photo Film Co., Ltd.Inventors: Hitoshi Noguchi, Shinji Saito
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Patent number: 6893723Abstract: A high density magnetic recording medium having improved dispersibility in a non-magnetic layer, excellent surface properties, electromagnetic conversion properties and durability is provided. The magnetic recording medium comprises a non-magnetic substrate, a non-magnetic layer disposed on the non-magnetic substrate, and a magnetic layer disposed on the non-magnetic substrate via the non-magnetic layer containing at least carbon black and a radiation curing type binder, wherein the radiation curing type binder contains a radiation curing type polyurethane resin having both a basic polar group and a sulfur-containing polar group in a molecule. The basic polar group is preferably an amino group, and the sulfur-containing polar group is preferably a sulfonic metal basic group.Type: GrantFiled: July 31, 2003Date of Patent: May 17, 2005Assignee: TDK CorporationInventor: Shigeo Kurose
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Patent number: 6893747Abstract: A magnetic tape is disclosed, comprising a support having thereon a magnetic layer comprising ferromagnetic particles and a binder as the main components, (i) the magnetic tape being for use in a magnetic recording/reproducing system in which signals recorded are reproduced with a magneto resistive head, (ii) the ferromagnetic particles contained in the magnetic layer being hexagonal-ferrite magnetic particles having an average tabular diameter of from 10 to 40 nm, and the magnetic layer having a machine direction coercive force Hc of from 158 to 350 kA/m, a squareness ratio SQ? as measured in the direction perpendicular to the magnetic plane of 0.5 or lower, and a thickness of from 30 to 300 nm.Type: GrantFiled: June 18, 2002Date of Patent: May 17, 2005Assignee: Fuji Photo Film Co., Ltd.Inventor: Kiyomi Ejiri
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Patent number: 6890670Abstract: The present invention is directed to methods for making magnetically modified electrodes and electrodes made according to the method. Such electrodes are useful as electrodes in batteries, such as Ni-MH batteries, Ni—Cd batteries, Ni—Zn batteries and Ni—Fe batteries.Type: GrantFiled: September 16, 2003Date of Patent: May 10, 2005Assignee: University of Iowa Research FoundationInventors: Johna Leddy, Pengcheng Zou
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Patent number: 6890585Abstract: A method of manufacturing a magnetic recording medium which includes a bonding sub-layer substantially and forms a lubricant layer having a width. A method of manufacturing a magnetic recording medium includes the steps of: a) laminating an underlayer, a magnetic layer for recording, and a protection layer of amorphous carbon on a substrate of the magnetic layer for recording medium in turn, and b) repeating a process to the protection layer of amorphous carbon comprising an application process of applying a lubricant, a subsequent ultraviolet rays treatment process, and a subsequent washing process for removing the lubricant which is not connected to the protection layer of amorphous carbon, the process being repeated plural times.Type: GrantFiled: August 31, 2001Date of Patent: May 10, 2005Assignee: Fujitsu LimitedInventors: Yuichiro Itai, Yoshiharu Kasamatsu
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Patent number: 6890631Abstract: A flexible magnetic-tape substrate is coated on both sides with an underlayer of relatively-low coercivity magnetic medium, which in turn is coated with a submicron layer of chromium dioxide in ultra small particles having a high coercivity. For longitudinal magnetic recording systems, magnetic layers with a coercivity of at least 1,500 Oe with underlayers having a coercivity between 25 and 500 Oe are used. For helical magnetic recording systems, magnetic layers with a coercivity of at least 2,000 Oe with underlayers having a coercivity between 25 and 800 Oe are used. These properties greatly reduce the effects of neighboring magnetic fields, thereby improving signal retention and virtually eliminating print-through and contact recording.Type: GrantFiled: June 10, 2002Date of Patent: May 10, 2005Assignee: International Business Machines CorporationInventor: Richard Lionel Bradshaw
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Patent number: 6890646Abstract: Provided is a particulate magnetic recording medium for high-density recording maintaining a high C/N ratio achieving good surface recording density, exhibiting little dropout, and having a low error rate. The magnetic recording medium comprises a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer comprising a ferromagnetic powder and a binder in this order on at least one surface of a nonmagnetic support. Said nonmagnetic support comprises a filler having an aspect ratio ranging from 50 to 10,000 and a thickness ranging from 0.5 to 5 nm.Type: GrantFiled: April 15, 2003Date of Patent: May 10, 2005Assignee: Fuji Photo Film Co., Ltd.Inventors: Katsuhiko Meguro, Masatoshi Takahashi
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Patent number: 6884526Abstract: High areal recording density, magnetic hard disk recording media including CSS landing zones with laser-textured surfaces having shallow bump heights of from about 40 to about 80 ?, bump spacing in the circumferential and radial directions of from about 10 to about 30 ?m, and bump diameter of from about 4 to about 8 ?m, are provided for use in disk drive systems utilizing padded head sliders operating at very low head slider flying heights of about 0.7 ?inch or below.Type: GrantFiled: March 25, 2003Date of Patent: April 26, 2005Assignee: Seagate Technology LLCInventors: Haun Tang, Jing Gui, Samuel John Falcone, Michael Joseph Stirniman, Li-Ping Wang
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Patent number: 6878398Abstract: A method of manufacturing a magnetic recording medium which includes a bonding sub-layer substantially and forms a lubricant layer having its enough width. A method of manufacturing a magnetic recording medium includes the steps of: a) laminating an underlayer, a magnetic layer for recording, and a protection layer of amorphous carbon on a substrate of the magnetic recording medium in turn, and b) repeating a progress to said protection layer of amorphous carbon comprising an application process of applying a lubricant, a subsequent ultraviolet rays treatment process, and a subsequent washing process for removing the lubricant which is not connected to the protection layer of amorphous carbon plural times.Type: GrantFiled: May 4, 2004Date of Patent: April 12, 2005Assignee: Fujitsu LimitedInventors: Yuichiro Itai, Yoshiharu Kasamatsu
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Patent number: 6878426Abstract: A method of manufacturing a magnetic recording medium, comprises steps of providing a non-magnetic substrate for a magnetic medium, the substrate including at least one major surface having a contact start/stop (CSS) or landing zone and a data zone; and forming a pattern of recesses in the substrate surface in said CSS or landing zone by embossing utilizing a stamper having a surface including a negative image pattern of said pattern of recesses. Embodiments of the invention include magnetic media comprising a non-magnetic substrate including at least one major surface having a contact start/stop (CSS) or landing zone and a data zone, said substrate surface in said CSS or landing zone comprising an embossed pattern of recesses. In addition, the data zone of the substrate surface may include an embossed servo pattern formed simultaneously with the embossed pattern of recesses formed in the landing zone.Type: GrantFiled: September 25, 2003Date of Patent: April 12, 2005Assignee: Seagate Technology LLCInventors: James Edward Angelo, Mukund Channagiri Rao, Alexei Hiram Sacks, Timothy Francis Ellis, David Kuo, Serge Jacques Fayeulle