Magnetic Feature Patents (Class 428/900)
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Patent number: 6455174Abstract: A magnetic recording medium comprises, on a substrate, a recording auxiliary layer, a recording holding layer, recording control layer, and a recording layer. The recording layer is constructed by using a ferri-magnetic material having perpendicular magnetization. The data can be recorded at a super high density by using the recording and reproducing head of the present invention, because the recording layer has the perpendicular magnetization. The disappearance of data, which would be otherwise caused by the thermomagnetic relaxation phenomenon, is suppressed after recording the data, because the recording layer has large coercive force at the room temperature. The data, which is recorded at the super high density on the magnetic recording medium, can be reproduced by using a magnetic resistance element carried on the recording and reproducing head.Type: GrantFiled: November 3, 1999Date of Patent: September 24, 2002Assignee: Hitachi Maxell, Ltd.Inventors: Hiroki Takao, Yuji Yamazaki, Susumu Imai, Hiroyuki Awano, Katsusuke Shimazaki
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Patent number: 6455101Abstract: A method and apparatus for depositing a protective film on a data recording disk, including the steps of depositing a magnetic film layer as a data recording layer on a surface of a substrate while the substrate is at a magnetic film deposition temperature; heating the substrate with the magnetic film layer thereon to a protective film deposition temperature; and depositing a protective film on the magnetic film layer while the substrate is at the protective film deposition layer; wherein the protective film deposition temperature is higher than the magnetic film deposition temperature.Type: GrantFiled: July 18, 2000Date of Patent: September 24, 2002Assignee: Anelva CorporationInventors: Hiromi Sasaki, Osamu Watabe, Naoki Watanabe
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Patent number: 6451424Abstract: The object of the present invention is to improve the thermal properties while maintaining the optical performance index. In the constitution having the light-permeable first dielectric layer, magneto-optical recording layer, light-permeable metal layer 1 nm to 10 nm in thickness and having layer heat diffusion as compared with the magneto-optical recording layer, light-permeable second dielectric layer, and metal reflecting film laminated sequentially from the light incidence side, an appropriate Kerr enhancement effect is obtained, the optical performance index is maintained, and temperature rise can be suppressed.Type: GrantFiled: February 2, 2000Date of Patent: September 17, 2002Assignee: Sony CorporationInventor: Yuichi Sabi
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Patent number: 6452385Abstract: A manufacturing method of a MR sensor includes forming a MR multi-layered structure of a first anti-ferromagnetic material layer, a first ferromagnetic material layer (pinned layer) which receives bias magnetic field caused by exchange coupling with the first anti-ferromagnetic material layer, a nonmagnetic material layer and a second ferromagnetic material layer (free layer) which changes its magnetization direction in response to magnetic signal applied thereto, depositing a protection layer on the MR multi-layered structure, removing full depth of at least end regions of the protection layer and a partial depth of end regions of the second ferromagnetic material layer, and forming a second anti-ferromagnetic material layer for exchange coupling to control magnetic domain in the second ferromagnetic material layer, on at least the end regions of the second ferromagnetic material layer.Type: GrantFiled: February 4, 2000Date of Patent: September 17, 2002Assignee: TDK CorporationInventors: Koji Shimazawa, Yoshihiro Tsuchiya, Satoru Araki
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Patent number: 6447935Abstract: A method and system for providing a spin valve for use in a magnetoresistive head is disclosed. The method and system include providing a synthetic pinned layer, a nonmagnetic spacer layer, and a free layer. The free layer has a first magnetization canted from a first direction by a first angle. The nonmagnetic spacer layer is disposed between the free layer and the synthetic pinned layer. The synthetic pinned layer has a second magnetization in a second direction. The second direction is canted from a third direction that is transverse to the first direction by a second angle. The second magnetization is substantially orthogonal to the first magnetization.Type: GrantFiled: November 23, 1999Date of Patent: September 10, 2002Assignee: Read-Rite CorporationInventors: Jing Zhang, Ningjia Zhu, Yiming Huai, Amritpal Singh Rana, Wenjie Chen
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Patent number: 6449167Abstract: A method and system with a magnetically attractive breadboard and associated devices for constructing and testing electronic circuits. The breadboard can comprise a single or multi-layer circuit board with metallic foil conductors that can be connected to magnetically attractive pads. Electrical contacts between the pads and foil conductors can be made by wrapping the foil over an edge of insulating material. The insulating material can comprise a flexible insulation sheet with the desired circuit printed thereon. The electronic components are preferably supported by component holders which contain magnets that are attracted to the breadboard. The component holders facilitate attachment of the components to the foil conductors. A circuit can be built by selecting the desired component holder, plugging he component into the component holder, and then attaching the component holder to the breadboard on the proper foil conductor to complete the circuit.Type: GrantFiled: October 13, 2000Date of Patent: September 10, 2002Inventor: Arthur F. Seymour
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Patent number: 6447936Abstract: Magnetic recording medium includes at least two layers having different magnetic anisotropy constants formed on a substrate and the perpendicular magnetic anisotropy of the second magnetic film of those magnetic films, far from the substrate surface, made equal to or larger than that of the first magnetic film near to the substrate surface, thus improving the magnetic isolation of the first magnetic film near to the substrate surface.Type: GrantFiled: June 15, 2000Date of Patent: September 10, 2002Assignee: Hitachi, Ltd.Inventors: Masaaki Futamoto, Nobuyuki Inaba, Yoshiyuki Hirayama, Yukio Honda, Kazuetsu Yoshida, Kenya Ito
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Patent number: 6440520Abstract: A method for making a patterned magnetic recording disk uses patterned ion implantation of the disk substrate. Energetic ions, such as He, N or Ar ions, are directed to the disk substrate through a mask, preferably a non-contact mask. They are implanted into the substrate, and the process causes localized topographic distortions in the substrate surface. A magnetic layer is then deposited over the substrate in the conventional manner, such as by sputtering. The result is a disk with patterned magnetic regions that are raised above the substrate surface. Because these regions are elevated, they are closer to the recording head in the disk drive and can thus be individually recorded to form discrete magnetic bits. Depending on the type of substrate used, the ion implantation can cause either localized swelling to form pillars or localized compaction to form pits. The patches of magnetic material on the tops of the pillars, or on the substrate surface between the pits, form the discrete magnetic bits.Type: GrantFiled: July 9, 1999Date of Patent: August 27, 2002Assignees: International Business Machines Corporation, University of New Orleans FoundationInventors: John Edward Eric Baglin, Mark Whitney Hart, Andrew John Kellock, Bruce David Terris, Koichi Wago, Dieter Klaus Weller, Liesl Folks
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Patent number: 6440522Abstract: A method of producing a security element for electronically securing an object, a device for producing the security element and the security element itself form aspects of the present invention. The security element includes a strip element embedded in sheathing. The sheathing has a melting temperature below that of the strip element. The method has associated steps and the device has associated elements for producing the security element from the strip element and sheathing. In each aspect, the ends of the strip element and sheathing are heated and the sheathing ends pulled to seal the strip element in the sheathing.Type: GrantFiled: September 14, 1999Date of Patent: August 27, 2002Assignee: Meto International GmbHInventors: Detlef Duschek, Gordon Klassen
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Patent number: 6441611Abstract: A magnetic sensor utilizing a giant magnetoresistance (GMR) effect, wherein an insulation layer with a contact hole is formed on a lower terminal layer, a GMR layer is formed thereover on the region including the entire contact hole and at least the surrounding insulation layer, and an upper terminal layer is formed thereover. The sensor offers several advantages in that it is easy to manufacture and is compact, and has a high degree of resistance change.Type: GrantFiled: December 27, 2000Date of Patent: August 27, 2002Assignee: Fujitsu LimitedInventor: Yoshihiko Seyama
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Patent number: 6440589Abstract: A magnetic recording disk has a magnetic recording layer that includes a ferromagnetic host layer and a ferromagnetic overlay deposited directly on the host layer with an effective overlay thickness in the range of 1-40 Angstroms. The ferromagnetic material used in the overlay contains Co, Fe and/or Ni and has a magnetic moment significantly greater than that of the material in the ferromagnetic host layer. The ferromagnetic overlays improve the thermal stability of superparamagnetic grains contained within the host layers by magnetically coupling the grains through bridging. The enhanced thermal stability of the media allows for the use of thinner ferromagnetic host layers, and leads to lower remanent magnetization-thickness product (Mrt) values and higher recording densities.Type: GrantFiled: June 2, 1999Date of Patent: August 27, 2002Assignee: International Business Machines CorporationInventors: Eric Edward Fullerton, David Thomas Margulies, Ernesto Esteban Marinero, Manfred Ernst Schabes
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Patent number: 6440545Abstract: A powder for use in the lower layer of a coating magnetic recording medium, comprising acicular particles with a mean major axis length in a range of from 0.01 to 0.5 &mgr;m and a mean minor axis length in a range of from 0.01 to 0.05 &mgr;m, provided that the acicular particles are flat acicular particles which, when cut in a direction perpendicular to the major axis, uniformly exhibit a cross section having a larger width to smaller width ratio of greater than 1, and that the quantity of discharged H2O at 100° C. is in a range of from 0.1 to 2.0% by weight.Type: GrantFiled: August 9, 2000Date of Patent: August 27, 2002Assignee: Dowa Mining Co., Ltd.Inventors: Seiichi Hisano, Kazuhisa Saito, Kazushi Sano, Yoshichika Horikawa
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Patent number: 6436560Abstract: A magnetic head comprises: an induction type head for recording including a lower magnetic core, a writing gap film formed on the lower magnetic core, an upper magnetic core having a track portion and a portion spreading from the track portion, a plurality of insulating films laminated between the lower magnetic core and the upper magnetic core, and a coil formed between the plurality of insulating films. One of the plurality insulating films is an insulating film determining a zero throat level position. The track portion of the upper magnetic core is an air bearing surface. A magnetoresistance effect type head for reproducing includes a lower shielding film and a magnetoresistance effect sensor film is formed between the lower shielding film and the lower magnetic core.Type: GrantFiled: June 30, 1999Date of Patent: August 20, 2002Assignee: Hitachi, Ltd.Inventors: Atsushi Kato, Koji Kaneyama, Kiyonori Shiraki
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Patent number: 6436526Abstract: A magneto-resistive effect element includes a first ferromagnetic film; a second ferromagnetic film; and a first nonmagnetic film interposed between the first ferromagnetic film and the second ferromagnetic film. The first ferromagnetic film has a magnetization more easily rotatable than a magnetization of the second ferromagnetic film by an external magnetic field. The first ferromagnetic film has an effective magnetic thickness of about 2 nm or less.Type: GrantFiled: June 16, 2000Date of Patent: August 20, 2002Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Akihiro Odagawa, Hiroshi Sakakima, Masayoshi Hiramoto, Nozomu Matsukawa
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Patent number: 6436522Abstract: A process for the preparation of high-quality magnetic dispersions having an Hc>120 kA/m, a residual induction Mr/Mm≧0.9 and an orientation ratio of about 2.7 achieves, with a self-purging single-shaft blade-type kneading apparatus, very advantageous magnetic values of the magnetic coatings and excellent tape characteristics if at least the following features are fulfilled: a) the radial shear gradient in the gap between blade circumference and housing wall is from about 150 to about 1600, in particular from about 500 to about 1400, l/sec b) the circumferential velocity of the kneading blade is from about 20 to about 80, in particular from about 35 to about 60, cm/sec. The magnetic dispersion prepared can be used in particular for data and video recording media having high recording and storage rates.Type: GrantFiled: February 14, 2001Date of Patent: August 20, 2002Assignee: EMTEC Magnetics GmbHInventors: Axel Schünemann, Hans-Dieter Zettler, Peter Nagel
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Patent number: 6436520Abstract: A magnetic display sheet of the present invention comprises: a magnet sheet having a magnetized surface, and a non-magnetized surface, which magnet sheet comprises: 400 to 1,900 parts by weight of at least one kind of magnetic particles selected from the group consisting of magnetoplumbite-structure ferrite particles and rare-earth magnet particles, as a filler, and 100 parts by weight of a binder comprising 50 to 95% by weight of at least one thermoplastic elastomer selected from the group consisting of a styrene-isoprene-styrene block copolymer resin, a styrene-ethylene.butylene-styrene block copolymer resin and an ethylene-propylene copolymer rubber, and 5 to 50% by weight of at least one soft polyolefin selected from the group consisting of a propylene homopolymer and a propylene-ethylene copolymer; and a printing paper sheet for being printed on, said paper sheet being bonded to said non-magnetized surface of said magnet sheet.Type: GrantFiled: September 1, 2000Date of Patent: August 20, 2002Assignee: Toda Kogyo CorporationInventor: Kazumi Yamamoto
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Patent number: 6432563Abstract: The present invention provides a magnetic recording media incorporating Zn containing layers in close proximity to a magnetic layer to provide media having increased coercivity and lower noise. The Zn containing layer can be incorporated in a rotating, translating or stationary recording media to operate in conjunction with magnetic transducing heads for recording and reading of magnetic data, as well as other applications. The magnetic recording medium of the invention preferably includes a Co or Co alloy film magnetic layer, underlayer structures to promote epitaxial crystalline structure in the magnetic layer, and a Zn containing layer to promote isolation between the magnetic grains. The medium can further include seed layers, underlayers, intermediate layers, and overlayers. The process of manufacture includes promoting diffusion of Zn to the magnetic layer grain boundaries.Type: GrantFiled: April 3, 2000Date of Patent: August 13, 2002Assignee: Carnegie Mellon UniversityInventors: Jie Zou, David N. Lambeth, David E. Laughlin
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Patent number: 6432520Abstract: A lightweight, magnetic sign assembly containing a magnetic sign. The magnetic sign contains a flexible substrate. Magnetic ink is bonded to either the top or bottom surface of the substrate, and ink is deposited over the top surface of the flexible substrate. Graphic images are presented by the top ink layer. The sign is lightweight, weighing less than about 6 ounces per square foot.Type: GrantFiled: December 11, 2000Date of Patent: August 13, 2002Assignee: Storeimage Programs Inc.Inventors: Adrian W. Pynenburg, Martin S. Cross
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Patent number: 6432562Abstract: High areal density magnetic recording media exhibiting high magnetic performance, e.g., narrow PW50, and high OW, and high SNR, are formed with a NiAlRu seedlayer. Embodiments of the present invention include sputter depositing a NiAlRu seedlayer on a non-magnetic substrate and sequentially depositing thereon a Cr or Cr alloy underlayer, e.g., CrMo, CrMn, CrV or CrW, a magnetic layer, e.g., a Co—Cr-containing magnetic alloy layer, and a protective overcoat, e.g., a carbon-containing protective overcoat.Type: GrantFiled: September 10, 1999Date of Patent: August 13, 2002Assignee: Seagate Technology LLCInventors: Stella Z. Wu, Qixu Chen, Samuel D. Harkness, IV, Rajiv Y. Ranjan
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Patent number: 6432503Abstract: A magnetic recording medium is described, which comprises a support having thereon a magnetic layer comprising a ferromagnetic metal powder dispersed in a binder, which is a magnetic recording medium for recording signals of from 0.17 to 2 G bit/inch2 of areal recording density, wherein the coercive force of said magnetic layer is 1,800 Oe or more, said ferromagnetic metal powder comprises Fe and Co, and the atomic ratio of Al/(Fe+Co) is from 3.0 to 15.4%.Type: GrantFiled: March 30, 1998Date of Patent: August 13, 2002Assignee: Fuji Photo Film Co., Ltd.Inventors: Masahi Aonuma, Shinji Saito, Hitoshi Noguchi, Nobuo Yamazaki
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Patent number: 6428869Abstract: A sheet or strip of discreet magnets disposed on a common backing and a method of manufacturing a plurality of discreet magnets detachably adhered to a common backing is provided. The method includes the passing of a magnetic substrate that is detachably adhered to a common backing in front of a die. The die is equipped with an internal ejector so that when the die is moved towards the substrate and the cutting edge of the die cuts the substrate, an internal ejector engages the cut portion of the substrate that forms a cut magnet. As the die is withdrawn from the substrate, the ejector maintains a pressing engagement against the cut magnet to prevent the cut magnet from being pulled off of the backing. A similar apparatus may be provided for a stripper disposed outside of the die to prevent waste substrate from being pulled off of the backing as the die is removed. Both the stripper and internal ejector are pulled off of the magnetic material after the die has been successfully removed.Type: GrantFiled: July 17, 1998Date of Patent: August 6, 2002Assignee: Promotional Ideas, Inc.Inventors: Mehmet Sami Ozgen, Chris Bohlin
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Publication number: 20020102442Abstract: The invention discloses an iron-based alloy sheet as a material for preparing a magnetic yoke member to build up a magnetic circuit in a hard-disk voice-coil motor as well as a magnetic yoke member made from such a sheet material. With an object to improve the magnetic circuit in respect of compactness and flatness, the iron-based alloy forming the sheet material contains inherent side elements including C, Si, Mn, P, S, Al, O and N each in a specified amount and is characterized by specified values of saturated magnetic flux density, maximum magnetic permeability and coercive force. The iron-based alloy may further contain up to 10% by weight of cobalt and/or one or a combination of adjuvant elements selected from Ti, Zr, Nb, Mo, Cr, V, Ni, W, Ta and B.Type: ApplicationFiled: September 5, 2001Publication date: August 1, 2002Inventors: Masanobu Shimao, Takehisa Minowa, Masaaki Nishino
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Patent number: 6426157Abstract: The present invention provides a perpendicular magnetic recording medium 11 having a perpendicular magnetization film 22 formed on a substrate 20, wherein a high perpendicular orientation film 24 having higher perpendicular orientation than that of the perpendicular magnetization film 22 is formed over or/and under the perpendicular magnetization film 22.Type: GrantFiled: August 3, 1999Date of Patent: July 30, 2002Assignee: NEC CorporationInventors: Hirotaka Hokkyo, Shinzo Tsuboi, Katsumichi Tagami
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Patent number: 6426156Abstract: A magnetic garnet single crystal film used for a magnetostatic wave device has a Pb content in the range of from more than zero to about 4,000 ppm by weight.Type: GrantFiled: January 30, 2001Date of Patent: July 30, 2002Assignee: Murata Manufacturing Co., Ltd.Inventor: Masaru Fujino
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Patent number: 6423386Abstract: The magnet powder-resin compound particles substantially composed of rare earth magnet powder and a binder resin are in such a round shape that a ratio of the longitudinal size a to the transverse size b (a/b) is more than 1.00 and 3 or less, and that an average particle size defined by (a/b)/2 is 50-300 &mgr;m. They are produced by charging a mixture of rare earth magnet powder and a binder resin into an extruder equipped with nozzle orifices each having a diameter of 300 &mgr;m or less; extruding the mixture while blending under pressure though the nozzle orifices to form substantially cylindrical, fine pellets; and rounding the pellets by rotation.Type: GrantFiled: April 6, 1999Date of Patent: July 23, 2002Assignee: Hitachi Metals, Ltd.Inventors: Katsunori Iwasaki, Kazunori Tabaru
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Patent number: 6423431Abstract: In a magnetic recording medium such as a magnetic disk which has a multilayer structure including a supporting substrate, at least one underlayer supported by the substrate, and a magnetic layer overlying the underlayer, magnetic and parametric performance of the recording layer is enhanced by providing an underlayer comprising a chromium-aluminum ternary alloy (Cr—Al—X). The aluminum in the Cr—Al—X alloy is 0.5%-4.0% by atomic weight. A second underlayer of chromium or chrome alloy can be provided under the first underlayer in a multilayer structure.Type: GrantFiled: May 30, 2000Date of Patent: July 23, 2002Assignee: Maxtor CorporationInventors: Bunsen Y. Wong, Ji Feng Ying
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Patent number: 6423369Abstract: A molded product having pores in its surface, an inorganic powder, a fat and oil and media are placed into a treating vessel, and a kinetic energy is supplied to the contents of the treating vessel, thereby forcing the inorganic powder into the pores and hardening it in the pores. In another process, a molded product having pores in its surface and an inorganic powder producing material are placed into a treating vessel, and a kinetic energy is supplied to the contents of the treating vessel, thereby forcing an inorganic powder produced from the inorganic powder producing material into the pores and hardening it in the pores. The inorganic powder producing material performs a role of producing an inorganic powder by the collision of pieces of the inorganic powder producing material against one another, against the molded product and against the inner wall of the vessel, and a role as media for forcing the produced inorganic powder into the pores.Type: GrantFiled: April 21, 2000Date of Patent: July 23, 2002Assignee: Sumitomo Special Metals Co., Ltd.Inventors: Kohshi Yoshimura, Takeshi Nishiuchi, Fumiaki Kikui, Masahiro Asano, Takahiro Isozaki
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Patent number: 6420058Abstract: The invention aims to prevent inadvertent rewriting or erasure of servo information in a patterned medium based on the perpendicular recording mode. The magnetic recording medium of the invention includes recording tracks each having an array of unit minute recording portions of a magnetic material separated by non-recording portions of a nonmagnetic material. The recording tracks include data regions and servo regions. The unit minute recording portions in the data regions have substantially the same surface area as the unit minute recording portions in the servo regions. The invention satisfies ARS/ARD≧1.5 provided that the unit minute recording portion has an aspect ratio which is the thickness divided by the square root of the surface area, the unit minute recording portion in the data region has an aspect ratio ARD, and the unit minute recording portion in the servo region has an aspect ratio ARS.Type: GrantFiled: February 18, 2000Date of Patent: July 16, 2002Assignee: TDK CorporationInventors: Susumu Haratani, Tsutomu Aoyama
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Patent number: 6416879Abstract: The object of the present invention is to provide an Fe-based amorphous alloy thin strip capable of realizing an excellent soft magnetic property for use in alternating current applications while keeping a high magnetic flux density even in a composition range with a high Fe content, and an Fe-based amorphous alloy thin strip with which a core having an excellent soft magnetic property can be manufactured, even if there occurs a temperature difference among different portions of the core during annealing. The present invention is an Fe-based amorphous alloy thin strip having a high magnetic flux density, consisting of the main component elements of Fe, Si, B, C, and P and unavoidable impurities, characterized by having: a composition, in atomic %, of 82<Fe≦90, 2≦Si<4, 5<B≦16, 0.02≦C≦4, and 0.2≦P≦12; Bs of 1.74 T or more after annealing; B80 exceeding 1.5 T; and a low core loss of 0.12 W/kg or less.Type: GrantFiled: September 21, 2001Date of Patent: July 9, 2002Assignee: Nippon Steel CorporationInventors: Hiroaki Sakamoto, Yuichi Sato
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Patent number: 6415534Abstract: Fluid decorative structure including an enclosing body and a scat body. The enclosing body is made of a very soft transparent or semitransparent material and formed with an opening at bottom end. Fluids with different colors and specific weights are filled into the enclosing body. An insertion member has a patterned article and an ejecting device. The ejecting device is composed of a tube body and a piston disposed in the tube body. When a rotary disc is rotated and a first magnetic member is moved to a position right under a second magnetic member, the first magnetic member will repel the second magnetic member to make the piston periodically move upward within the tube body so as to eject the second fluid with the heavier specific weight from the spout of the tube body.Type: GrantFiled: August 30, 2000Date of Patent: July 9, 2002Inventor: Chu-Yuan Liao
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Patent number: 6416864Abstract: Black magnetic toner comprising: a binder resin, and black magnetic composite particles comprising: magnetic iron oxide particles having an average particle diameter of 0.055 to 0.95 &mgr;m; a coating layer formed on the surface of said magnetic iron oxide particles, comprising at least one organosilicon compound selected from the group consisting of: (1) organosilane compounds obtainable from alkoxysilane compounds, (2) polysiloxanes or modified polysiloxanes, and (3) fluoroalkyl organosilane compounds obtainable from fluoroalkylsilane compounds; and a carbon black coat formed on said coating layer comprising said organosilicon compound, in an amount of 1 to 25 parts by weight based on 100 parts by weight of said magnetic iron oxide particles. Such a black magnetic toner can be free from being deteriorated in electric resistance due to the existence of the carbon black coat, and as a result, is suitable as a high-resistance or insulated magnetic toner.Type: GrantFiled: April 3, 2000Date of Patent: July 9, 2002Assignee: Toda Kogyo CorporationInventors: Kazuyuki Hayashi, Hiroko Morii, Yasuyuki Tanaka, Seiji Ishitani
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Patent number: 6416881Abstract: Sputter-deposited amorphous metal oxide films on substrates comprising an aluminum-containing support and a Ni-containing pre-coat reduce Ni ion migration significantly from the substrate onto the top surface of the magnetic recording media. Longitudinal magnetic recording media deposited on metal oxide sealing layers have very good magnetic recording performances and are suitable for high density recording application.Type: GrantFiled: May 15, 2000Date of Patent: July 9, 2002Assignee: Seagate Technology LLCInventors: Lin Huang, Liji Huang, Qixu David Chen, Charles Leu, Rajiv Yadav Ranjan
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Patent number: 6416839Abstract: Stiction failure of a magnetic recording medium is reduced by forming a lubricant topcoat having a first thickness over the landing zone greater than a second thickness over the data zone, with a sharp transition step having an angle of at least about 70° with respect to a line perpendicular to the surface. Embodiments include depositing a lubricant topcoat at a substantially uniform thickness and reducing the thickness of the lubricant topcoat over the data zone by about 20% to about 80% employing a laser light beam to volatilize the lubricant.Type: GrantFiled: March 5, 2001Date of Patent: July 9, 2002Assignee: Seagate Technology LLCInventors: Jialuo Jack Xuan, Chung-Yuang Shih, Xiaohua Shel Yang, Youming Liu, Vidya K. Gubbi
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Patent number: 6416830Abstract: A tube for externally covering or bundling electric cables is provided for suppressing radiation of undesired electromagnetic waves. The tube is made of a material in which soft magnetic powder is mixed with and dispersed into an organic binding agent. For protecting the cable from the undesired electromagnetic waves from the exterior, it is preferable to provide a conductor layer at an outer side of a composite magnetic layer. For facilitating mounting onto the cable, the tube is provided with a slit in a longitudinal direction. Alternatively, the cable may have a spiral structure. As an organic binding agent, it is preferable to use an elastomer which is excellent in extensible property. Further, it is preferable that the soft magnetic powder is powder being essentially flat.Type: GrantFiled: April 24, 1998Date of Patent: July 9, 2002Assignee: Tokin CorporationInventors: Shigeyoshi Yoshida, Mitsuharu Sato
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Patent number: 6413608Abstract: The thin film magnetic disk of the present invention includes a non-metallic substrate having a seed layer deposited on the substrate, an underlayer deposited upon the seed layer composed of a chromium alloy having a relatively high oxygen concentration portion of from 2,000 ppm to 20,000 ppm and preferably approximately 4,000 ppm to 12,000 ppm, followed by a relatively low oxygen concentration portion of from 0-2,000 ppm, and preferably from 500 ppm to 1,500 ppm and a magnetic layer that is deposited upon the underlayer. The underlayer total thickness is in the range of from approximately 250 Å to approximately 700 Å with a preferred thickness of approximately 450 Å, wherein approximately half of the underlayer thickness is the high oxygen concentration portion and half is the low oxygen concentration portion.Type: GrantFiled: June 18, 1999Date of Patent: July 2, 2002Assignee: International Business Machines CorporationInventors: Xiaoping Bian, Mary Frances Doerner, Shanlin Duan, Jinshan Li, Mohammad Taghi Mirzamaani
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Publication number: 20020081446Abstract: A process of making a magnetic assembly having at least one magnetic layer and at least one printable substrate layer including the steps of providing a magnetic composition comprising about 70 wt-% to about 95 wt-% of at least one magnetic material and about 5 wt-% to about 30 wt-% of at least one thermoplastic binder, forming the magnetic composition into a magnetic layer, and directly applying the magnetic composition at an elevated temperature in molten form to a printable substrate layer, and to the magnetic composition and any articles made therefrom.Type: ApplicationFiled: November 21, 2001Publication date: June 27, 2002Inventors: Randall A. Boudouris, Raymond S. Richards
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Patent number: 6410170Abstract: A preferred method of the present invention provides an improved thin film for carrying magnetic flux. With the preferred method, the magnetic thin film may be formed by depositing Fe by reactive sputtering using N2 to form a thin film comprising &agr;-Fe and &ggr;-Fe4N. With this method, the relative percentage of &ggr;-Fe4N in the deposited film is increased to provide expanding lattice constants for both the &agr;-Fe and the &ggr;-Fe4N. Increasing &ggr;-Fe4N increases resistivity while expanding lattice constants to provide improved coercivity at higher resistivity. Increasing the percentage of &ggr;-Fe4N to provide expanding lattice constants for both the &agr;-Fe and the &ggr;-Fe4N may be accomplished by adjusting sputtering power, N2 gas percentage, a flow rate of N2, and substrate bias.Type: GrantFiled: May 20, 1999Date of Patent: June 25, 2002Assignee: Read-Rite CorporationInventors: Yingjian Chen, Chester Qian
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Patent number: 6410133Abstract: A magnetic recording medium includes a non-magnetic substrate, an inorganic compound layer that is formed on the substrate and which contains a crystalline first oxide and a second oxide, and a magnetic layer that is formed on the inorganic compound layer. The crystalline first oxide comprises at least one oxide selected from cobalt oxide, chromium oxide, iron oxide and nickel oxide. The second oxide comprises at least one oxide selected from silicon oxide, aluminum oxide, titanium oxide, tantalum oxide and zinc oxide. The second oxide is present at a grain boundary of crystal grains of said first oxide. According to the present invention, magnetic recording media low in noise and diminished in thermal fluctuation and thermal decay can be obtained by making fine the crystal grains of a magnetic layer and controlling the dispersion of the grain size. Thus, magnetic recording apparatuses can be realized which can perform an ultrahigh density magnetic recording of higher than 20 Gb/in2.Type: GrantFiled: January 6, 2000Date of Patent: June 25, 2002Assignee: Hitachi, Ltd.Inventors: Fumiyoshi Kirino, Nobuyuki Inaba, Ken Takahashi, Takashi Naitou, Sumio Hosaka, Eiji Koyama, Motoyasu Terao, Hiroki Yamamoto, Hiroki Kuramoto
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Patent number: 6403242Abstract: The present invention provides a magnetic recording medium having a magnetic layer deposited on a substrate through a single-layer underlayer or a multilayer-underlayer, the magnetic layer includes magnetic crystal grains having an acicular structure or amorphous magnetic particles, an average grain size of the magnetic grain and a grain-size dispersion normalized by the average grain size are less than 16 nm and less than 0.5, respectively, a value Ku·v/kT which results from dividing a product of a magnetic anisotropy constant Ku and a volume v of the magnetic grain by a product of a Boltzmann constant k and an absolute temperature T is selected to be greater than 60, and a film thickness of the magnetic layer falls within twice of the average grain size.Type: GrantFiled: March 14, 2000Date of Patent: June 11, 2002Assignee: Hitachi, Ltd.Inventors: Tetsuya Kanbe, Yoshio Takahashi, Akira Ishikawa, Ichiro Tamai, Yuzuru Hosoe, Yoshifumi Matsuda, Kiwamu Tanahashi, Tomoo Yamamoto
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Patent number: 6403194Abstract: An object of the present invention is to provide a magnetic recording medium which has a sufficient impact resistance to withstand its accidental collision with a magnetic head and is neither worn away nor fractured in the CSS area by contact or friction between the magnetic recording medium and the magnetic head even if the thickness of a protective filmy layer is reduced in the data area. In order to achieve this object, a magnetic film and a protective film are formed on a substrate, and for example, the other portion of said protective film than a portion where said protective film comes into contact with a magnetic head is made of not only carbon and nitrogen but also hydrogen for increasing the hardness of said protective film.Type: GrantFiled: August 23, 1999Date of Patent: June 11, 2002Assignee: Hitachi, Ltd.Inventors: Toshinori Ono, Yuuichi Kokaku, Yoshinori Honda, Hiroyuki Suzuki
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Patent number: 6403203Abstract: Magnetic recording medium includes at least two layers having different magnetic anisotropy constants formed on a substrate and the perpendicular magnetic anisotropy of the second magnetic film of those magnetic films, far from the substrate surface, made equal to or larger than that of the first magnetic film near to the substrate surface, thus improving the magnetic isolation of the first magnetic film near to the substrate surface.Type: GrantFiled: August 24, 1999Date of Patent: June 11, 2002Assignee: Hitachi, Ltd.Inventors: Masaaki Futamoto, Nobuyuki Inaba, Yoshiyuki Hirayama, Yukio Honda, Kazuetsu Yoshida, Kenya Ito
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Patent number: 6399174Abstract: A magnetooptical recording medium includes a first magnetic layer, a second magnetic layer whose Curie temperature is lower than that of the first magnetic layer, and a third magnetic layer, comprising a vertically-magnetizing film, whose Curie temperature is higher than that of the second magnetic layer. The first magnetic layer, the second magnetic layer and the third magnetic layer are in a state of exchange coupling with each other at a portion of a vertically-magnetizing film. A domain walls formed in the first magnetic layer moves when the temperature of the medium has been raised to at least the Curie temperature of the second magnetic layer.Type: GrantFiled: October 13, 2000Date of Patent: June 4, 2002Assignee: Canon Kabushiki KaishaInventors: Tsutomu Shiratori, Tomoyuki Hiroki
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Patent number: 6395388Abstract: The present invention provides an exchange coupling film having a stacked-film-structure consisting of a ferromagnetic film made of at least one material of Fe, Co and Ni, and an antiferromagnetic film, wherein the exchange coupling film made of a ferromagnetic material to which an element is added, is provided at the interface between the ferromagnetic film and the antiferromagnetic film so as to improve the lattice matching, which results in the enhancement of the exchange coupling force, and a magnetoresistance effect element including such an exchange coupling film as described above, and an electrode for supplying a current to the ferromagnetic film which constitutes the exchange coupling film.Type: GrantFiled: November 17, 1999Date of Patent: May 28, 2002Assignee: Kabushiki Kaisha ToshibaInventors: Hitoshi Iwasaki, Yuichi Ohsawa, Reiko Kondoh, Susumu Hashimoto, Atsuhito Sawabe, Yuzo Kamiguchi, Masashi Sahashi, Hiromi Fuke
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Patent number: 6395368Abstract: A glass-ceramic substrate for a magnetic information storage medium having a super flat surface comprises, as a predominant phase or phases, at least one crystal phase selected from the group consisting of lithium disilicate (Li2O.2SiO2, having an interplaner spacing of maximum peak intensity measured by an X-ray diffraction analysis within a range from 3.57 Å and 3.62 Å), quartz (SiO2, having an interplaner spacing of maximum peak intensity measured by an X-ray diffraction analysis within a range from 3.33 Å to 3.41 Å), quartz solid solution (SiO2 solid solution, having an interplaner spacing of maximum peak intensity measured by an X-ray diffraction analysis within a range from 3.33 Å to 3.41 Å), cristobalite (SiO2, having an interplaner spacing of maximum peak intensity measured by an X-ray diffraction analysis within a range from 4.04 Å to 4.Type: GrantFiled: August 4, 1999Date of Patent: May 28, 2002Assignee: Kabushiki Kaisha OharaInventors: Katsuhiko Yamaguchi, Naoyuki Goto
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Patent number: 6395373Abstract: A webstock device for providing a signaling function while being relatively camouflaged includes sheet-like webstock material, a cavity in the webstock material, a signaling device at least partly contained in the cavity, and means for retaining the signaling device at least partly in the cavity. The cavity in the webstock material is closed by respective layers of material and a cover layer can be printed with desired information, instructions, etc. The signaling device may be an accousto-magnetic signaling device, an RF device or other signaling device. The invention also includes methods and apparatus for making the webstock device and methods for using the device.Type: GrantFiled: February 11, 1998Date of Patent: May 28, 2002Assignee: Avery Dennison CorporationInventors: Norman A. Conti, Paul B. Germeraad
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Patent number: 6395400Abstract: A magnetic recording medium using a biaxially oriented aromatic polyamide film as a nonmagnetic support resulting in hardly any improper windings or edge damages. The magnetic recording medium includes a magnetic layer containing ferromagnetic powders dispersed in a binder formed on the nonmagnetic support, wherein the biaxially oriented aromatic support has a ratio of the loss tangent at a temperature of 40° C. to the loss tangent at a temperature of 100° C. of 0.7 or higher.Type: GrantFiled: July 12, 1999Date of Patent: May 28, 2002Assignee: Fuji Photo Film Co., Ltd.Inventors: Hiroo Inaba, Masaki Suzuki, Hiroaki Takano, Masatoshi Takahashi
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Patent number: 6391419Abstract: A magnetic recording medium, comprising a magnetic layer containing a ferromagnetic metal thin film having micro-size projections on surface thereof and formed by vacuum film forming method and provided at least on one side of a nonmagnetic substrate, a carbon protective layer and a lubricant provided on said magnetic layer, a central axis of a diamond indenter of trilateral pyramid having a tip sharp angle of 90° and a radius of curvature at tip of 35-50 nm being directed perpendicularly to the surface of the nonmagnetic substrate, pressure is applied on the carbon protective layer, and a load obtained when indentation depth of the indenter is 10-25 nm is divided by projection area of indenter contactor, and the quotient, i.e. micro-hardness, is within the range of 10-30 GPa.Type: GrantFiled: September 13, 2000Date of Patent: May 21, 2002Assignee: Fuji Photo Film Co., Ltd.Inventors: Kazutoshi Katayama, Kazuyuki Usuki
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Patent number: 6391450Abstract: Spindle-shaped goethite particles are disclosed, which contain not less than 0.5 and less than 8 atom % of Co based on the total Fe and 5 to 10 atom % of Al based on the total Fe, and have an average major axis diameter of 0.18 to 0.30 &mgr;m, a size distribution (standard deviation/major axis diameter) of not more than 0.22, an average minor axis diameter of 0.025 to 0.045 &mgr;m and an average aspect ratio is 5 to 10. Spindle-shaped hematite particles and spindle-shaped magnetic iron-based alloy particles are also disclosed, which are produced from the above goethite particles. The spindle-shaped goethite particles of the present invention provide spindle-shaped magnetic iron-based alloy particles which are excellent in dispersibility (high squareness and high orientation), excellent both in weatherability and in coercive force distribution, and are useful as household DAT, 8 mm, Hi-8 tapes, VTR tapes for business purposes, computer tapes or floppy disks.Type: GrantFiled: May 19, 2000Date of Patent: May 21, 2002Assignee: Toda Kogyo CorporationInventors: Kenji Okinaka, Masayuki Uegami
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Patent number: 6391483Abstract: A device including a magnetic material having a magnetization configuration that is circular in a plane, and a word line for producing a magnetic field in the plane, the magnetic field being radial with respect to a point in the plane and within the circular magnetization configuration.Type: GrantFiled: March 30, 1999Date of Patent: May 21, 2002Assignee: Carnegie Mellon UniversityInventors: Jian-Gang Zhu, Youfeng Zheng, Gary A. Prinz
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Patent number: RE37748Abstract: A Co-Pt based magnetic alloy which has been doped with a relatively high amount of nitrogen, e.g., or above 1 at. % is obtained having high coercivity, for example in the range of 1400 Oe or above, and an increased signal-to-noise ratio as compared to the same Co-Pt based alloy which has not been doped with nitrogen. The alloy is vacuum deposited, for example, by sputtering, and the nitrogen may be introduced from the sputtering gas or from the sputtering target.Type: GrantFiled: July 17, 2000Date of Patent: June 18, 2002Assignee: Komag, Inc.Inventors: Tu Chen, Tsutomu Tom Yamashita, Rajiv Yadav Ranjan, John Ko-Chen Chen, Keith Kadokura, Ting Joseph Yuen