Magnetic Feature Patents (Class 428/900)
  • Patent number: 6391423
    Abstract: A magnetic recording medium exhibiting satisfactory electromagnetic conversion characteristic and movement characteristics and incorporating a non-magnetic support member made of aromatic polyamide film. The magnetic recording medium incorporating a non-magnetic support member having a principal plane on which a magnetic layer constituted by at least a thin metal film is formed, wherein said non-magnetic support member has said principal plane on which at least said thin metal film is formed and on which small projections, the height of each of which is 10 nm to 40 nm from the central surface, are formed at a density of 1,000,000 pieces/mm2 to 20,000,000 pieces/mm2, and a bearing curve of the principal plane of said non-magnetic support member on which said small projection have been formed is such that the gradient of a straight line is −0.
    Type: Grant
    Filed: May 31, 2000
    Date of Patent: May 21, 2002
    Assignee: Sony Corporation
    Inventors: Satoshi Sato, Shinichi Matsumura
  • Publication number: 20020058123
    Abstract: A fastening component of a separable fastener has some portion that is necessary for its fastening function, such as the hooks, the base to which the hooks are attached or a substrate that is used for another purpose, comprised of a magnetically attractive constituent. Another portion of the fastening component is comprised of a magnetically inert constituent. The fastening element may be the hook portion or the loop portion of a typical fastener. The fastening elements and the base may be unitary, or of different precursors, such as in a woven fastener component. The magnetically inert constituent may comprise a polymeric plastic or a thermoplastic elastomer. The magnetic attractant may impregnate the magnetically inert constituent, or it may coat or be coated by the magnetically inert constituent. The magnetic attractant may comprise a metal powder. The metal may be selected from the group consisting of iron powder. The magnetic attractant may be an organo-iron or a rare earth metal.
    Type: Application
    Filed: December 31, 2001
    Publication date: May 16, 2002
    Applicant: Velcro Industries B.V.
    Inventors: Randall B. Kenney, Brian J. Routhier, Martin I. Jacobs
  • Patent number: 6387522
    Abstract: The present invention provides a grain-oriented electrical steel sheet, for a low noise transformer, capable of reducing higher harmonics which are highly audible and lowering noise effectively, and relates to a grain-oriented electrical steel sheet for a low noise transformer, characterized by imposing a film tension of 0.5 to 6.0 MPa on the surface by coating or a method corresponding thereto, without forming a glass film on the grain-oriented electrical steel sheet or, if a glass film is formed, after removing the glass film by an arbitrary method.
    Type: Grant
    Filed: May 30, 2001
    Date of Patent: May 14, 2002
    Assignee: Nippon Steel Corporation
    Inventors: Hisashi Mogi, Akira Sakaida, Masahiro Fujikura, Masato Mizokami
  • Patent number: 6387483
    Abstract: It is intended to reduce the media noise, and to improve the recording density dependence of read output voltage. The present invention provides a perpendicular magnetic recording media and its manufacturing process, wherein a perpendicular magnetic recording medium comprises a soft magnetic underlayer film and a perpendicular magnetizing film, these films being formed on a substrate in this order, a smoothness control film such as Cr film, being inserted between the substrate and the soft magnetic underlayer film. Therefore, perpendicular orientation and surface smoothness are improved for the perpendicular magnetizing film laminated on the smooth surface of the soft magnetic underlayer film. As the perpendicular orientation is improved for the perpendicular magnetizing film, the initial layer is reduced, thereby media noise being lowered and recording density dependence of read output voltage being improved.
    Type: Grant
    Filed: October 15, 1998
    Date of Patent: May 14, 2002
    Assignee: NEC Corporation
    Inventors: Hirotaka Hokkyo, Shinzo Tsuboi
  • Patent number: 6387550
    Abstract: A giant magnetoresistive material film includes at least two ferromagnetic layers of a NiFe alloy or NiFeCo alloy, which are formed on a substrate through a nonmagnetic layer of Au, Ag, Cu or Cr, wherein magnetization of at lest one of the ferromagnetic layers is pinned by a coercive force increasing layer of &agr;-Fe2O3 provided adjacent thereto and having a thickness of 200 to 1000 Å so as to increase coercive force of the ferromagnetic layer, and the other ferromagnetic layer has free magnetization so as to produce a change in magnetic resistance at a low magnetic field. The present invention also provides a method of producing the giant magnetoresistive material film and a magnetic head provided with the giant magnetoresistive material film.
    Type: Grant
    Filed: April 11, 2000
    Date of Patent: May 14, 2002
    Assignee: Alps Electric Co., Ltd.
    Inventors: Fumihito Koike, Naoya Hasegawa
  • Patent number: 6387549
    Abstract: A high-sensitivity magnetic sensor capable of detecting a nonequilibrium spin, uses an almost-spin-polarized ferromagnetic oxide in a high-quality trilayer arrangement including an intermediate layer made of a conductive nonmagnetic oxide not reacting with a ferromagnetic metallic oxide and having a lattice matching between a spin injection layer and a spin detection layer.
    Type: Grant
    Filed: June 29, 1999
    Date of Patent: May 14, 2002
    Assignee: NEC Corporation
    Inventors: Takeshi Obata, Takashi Manako, Yuichi Shimakawa
  • Patent number: 6387485
    Abstract: A flexible composite substrate is disclosed and includes a flexible carrier, a first adhesive and a second adhesive. The first adhesive is adhered to the flexible carrier and includes ferromagnetic material. The second adhesive is adhered to the first adhesive, and is for removably applying the flexible composite substrate to a receiving surface. The adhesive strength of the second material is greater than the adhesive strength of the first material.
    Type: Grant
    Filed: August 12, 1999
    Date of Patent: May 14, 2002
    Assignee: Flexcon Company, Inc.
    Inventors: Yan P. Bielek, William W. Sullivan
  • Patent number: 6387476
    Abstract: A magnetic functional element can operate stably and reliably with a satisfactorily low rate of power consumption if used to realize an enhanced degree of integration. The magnetic fuctional element comprises strain-sensitive magnetic layer 2 having a magnetic state variable with strain and a strain applying layer 3 adapted to apply strain to the strain-sensitive magnetic layer. The magnetic state of the strain-sensitive magnetic layer 2 is controlled by controlling the strain applied to the strain-sensitive magnetic layer 2. Thus, it is no longer necessary to generate a magnetic field by means of an electric current in order to change the magnetic state of the element.
    Type: Grant
    Filed: September 10, 1999
    Date of Patent: May 14, 2002
    Assignee: Sony Corporation
    Inventors: Yoh Iwasaki, Kazuhiro Bessho
  • Patent number: 6387548
    Abstract: The antiferromagnetic layer 4 is formed of the X—Mn alloy (X is an platinum group element) and the interface structure of with the pinned magnetic layer 3 is made to be non-coherent by properly adjusting the composition ratio of X. Consequently, the crystal structure of the antiferromagnetic layer 4 is transformed so as to obtain a large exchange anisotropic magnetic field by subjecting the layer to a heat treatment, making it possible to improve the reproduction characteristic over the conventional art.
    Type: Grant
    Filed: October 8, 1998
    Date of Patent: May 14, 2002
    Assignee: Alps Electric Co., Ltd.
    Inventors: Naoya Hasegawa, Masamichi Saito, Kazuya Oominato, Yutaka Yamamoto, Akihiro Makino
  • Patent number: 6383626
    Abstract: A magnetic ferrite paste is applied onto an Si substrate, and then sintered to form thereon a magnetic ferrite film having a mean composition that comprises from 40 to 50 mol % of Fe2O3, from 15 to 35 mol % of ZnO, from 0 to 20 mol % of CuO, and from 0 to 10 mol % of Bi2O3 with NiO and inevitable impurities as the balance. The magnetic ferrite film thus formed on an Si substrate is for magnetic devices, and it forms a region not containing CuO or having a CuO content of at most 5 mol % around its interface directly adjacent to the surface of the Si substrate. The adhesiveness of the magnetic ferrite film to the underlying Si substrate is high, and the reliability of the magnetic device having the magnetic film is therefore high.
    Type: Grant
    Filed: April 12, 2000
    Date of Patent: May 7, 2002
    Assignee: Kawatetsu Mining Co., Ltd.
    Inventors: Yasutaka Fukuda, Yoshihito Tachi
  • Patent number: 6383645
    Abstract: There is provided a glass-ceramic substrate for an information storage medium usable in an information storage device of the ramp loading system. The glass ceramic substrate has a Young's modulus (GPa)/specific gravity of 37 or over and includes 5.3 to 8 weight percent (expressed on an oxide basis) of Al2O3. The glass ceramic substrate has, as its predominant crystal phases, lithium disilicate (Li2O.2SiO2) and &agr;-quartz (&agr;-SiO2), has a coefficient of thermal expansion within a range from 65×10−7/° C. to 130×10−7/° C. within a temperature range from −50° C. to +70° C. and has a surface roughness (Ra) (arithmetic mean roughness) of 9 Å or below.
    Type: Grant
    Filed: March 2, 1999
    Date of Patent: May 7, 2002
    Assignee: Kabushiki Kaisha Ohara
    Inventors: Naoyuki Goto, Junko Ishioka, Yasuyuki Kawashima
  • Patent number: 6383637
    Abstract: Black magnetic iron oxide particles of the present invention having an average particle diameter of 0.1 to 0.3 &mgr;m, comprise: black spinel iron oxide particles as core particles; and a surface coat formed on the surface of each core particle, comprising fine spinel iron oxide particles, the content of FeO in a surface layer having a thickness of from a surface of each black magnetic iron oxide particle to about 3.5% per a radius of each black magnetic iron oxide particle, being 8 to 14% by weight based on the weight of Fe contained in said surface layer. Such black magnetic iron oxide particles not only have a sufficient blackness and excellent electrical properties, flowability and electrification property (charging property), but also exhibit a good compatibility with binder resins such as aromatic vinyl-based resins, acrylic-based resins and copolymer resins thereof, and a good dispersibility in these resins for a magnetic toner.
    Type: Grant
    Filed: April 13, 2000
    Date of Patent: May 7, 2002
    Assignee: Toda Kogyo Corporation
    Inventors: Hiromitsu Misawa, Koso Aoki, Suehiko Miura, Minoru Kozawa, Naoki Uchida, Nobuya Shimo
  • Patent number: 6383668
    Abstract: A magnetic recording disk has a magnetic recording layer formed on a special multilayered “host” layer. The host layer is a “synthetic antiferromagnetically”, i.e., at least two ferromagnetic films that are exchange-coupled antiferromagnetically (AF) to one another across a nonferromagnetic spacer film so that their magnetic moments are oriented antiparallel. The magnetic recording layer has a different composition from the top ferromagnetic film in the host layer and is ferromagnetically coupled to the top ferromagnetic film of the host layer. The magnetic volume V of the composite structure (magnetic recording layer and host layer) that determines the thermal stability will be approximately the sum of the volumes of the grains in the magnetic recording layer and the AF-coupled ferromagnetic films of the host layer.
    Type: Grant
    Filed: March 27, 2000
    Date of Patent: May 7, 2002
    Assignee: International Business Machines Corporation
    Inventors: Eric Edward Fullerton, David Thomas Margulies, Ernesto Esteban Marinero, Manfred Ernst Schabes
  • Patent number: 6383605
    Abstract: Disclosed is a magnetic recording medium comprising a flexible nonmagnetic support, a nonmagnetic layer containing nonmagnetic powder and a binder on the support, and a magnetic layer containing ferromagnetic powder and a binder on the nonmagnetic layer. The magnetic layer has an average thickness of from 0.01 or higher to 0.3 &mgr;m or lower, and the nonmagnetic layer has an average thickness of 0.5 &mgr;m or lower. The side of the flexible nonmagnetic support to which the nonmagnetic layer and the magnetic layer are formed has a PSD equal to or less than 0.5 nm2 in the wavelength of from 1 to 5 &mgr;m, and a PSD of 0.02 to 0.5 nm2 in the wavelength of from 0.5 &mgr;m or higher to less than 1 &mgr;m according to a surface roughness spectrum measured with an atomic force microscope. The flexible nonmagnetic support has a ratio, HD/TD, of Young's modulus in the direction of MD to the direction of TD of 1/5 or higher to 1/1 or lower.
    Type: Grant
    Filed: April 24, 2000
    Date of Patent: May 7, 2002
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Kiyomi Ejiri
  • Patent number: 6379810
    Abstract: The present invention provides a magnetic film expressed by a composition formula TaMbXcNdOe (T is a magnetic metal such as Fe, M is an alkaline earth metal such as Be, Mg, and Ca, and X is at least one selected from the group consisting of Y, Ti, Zr, Hf, V, Nb, Ta and lanthanoid), where a+b+c+d+e=100, 45 ≦a≦85, 5.5≦b≦28, 0.5≦c≦16, 6≦b+c≦28.5, 0.4 <b/c ≦56, 0≦d≦10, and 8≦d+e≦40. The magnetic film comprises mainly metal magnetic crystal grains having an average crystal grain diameter of not more than 15 nm and a grain boundary product. The grain boundary product substantially separates the metal magnetic crystal grains. The main component of the metal magnetic crystal grains is the T. The grain boundary product contains at least an oxide or a nitride of the M and the X. The magnetic film has a saturation magnetic flux density of not less than 0.8 T and an electric resistivity of not less than 80 &mgr;&OHgr;cm.
    Type: Grant
    Filed: January 18, 2000
    Date of Patent: April 30, 2002
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masayoshi Hiramoto, Yasuhiro Iwano, Hirosuke Mikami, Hiroyasu Tsuji, Hiroshi Sakakima
  • Patent number: 6379801
    Abstract: A fluoropolyether having a nonfunctional silane end group is applied to a magnetic recording medium to form a lubricant topcoat thereon. In an embodiment of the present invention, no less than about 70% of the lubricant applied to the magnetic recording medium forms a bonded topcoat thereto.
    Type: Grant
    Filed: December 6, 1999
    Date of Patent: April 30, 2002
    Assignee: Seagate Technology, LLC
    Inventors: Samuel J. Falcone, Michael J. Stirniman
  • Patent number: 6379775
    Abstract: A magnetic recording medium comprises a nonmagnetic substrate (1) of a crystallizable material and a lamina including at least a magnetic layer (3) formed thereon. The nonmagnetic substrate has a surface specified by a predetermined crystal grain size while the magnetic layer (3) has a magnetic crystal grain size dependent on the predetermined crystal size. The lamina may include an underlying layer (2) which is formed between the nonmagnetic substrate (1) and the magnetic layer (3) and which has a thickness selected to control the magnetic crystal grain size of the magnetic layer (3). The lamina may further comprise an intermediate layer (6) formed between the underlying layer (2) and the magnetic layer (3). Alternatively, an initial layer (7) may be formed between the nonmagnetic substrate (1) and the underlying layer (2).
    Type: Grant
    Filed: November 1, 2000
    Date of Patent: April 30, 2002
    Assignee: Hoya Corporation
    Inventor: Masato Kobayashi
  • Patent number: 6379774
    Abstract: A composite polyester film comprising (1) a base film C of an aromatic polyester which does not contain or contains inert particles having an average particle diameter of 5 to 2,000 nm in an amount of 0.001 to 5.
    Type: Grant
    Filed: May 20, 1999
    Date of Patent: April 30, 2002
    Assignee: Teijin Limited
    Inventors: Mitsuo Tojo, Toshikazu Uchida, Toshifumi Osawa
  • Patent number: 6376083
    Abstract: The present invention provides a magnetic recording medium having high dispersion property, good running durability and good preservation property, and it comprises at least one magnetic layer having ferromagnetic powder dispersed by a binder placed on a non-magnetic support member, whereby a polyurethane resin or a polyurethane urea resin consisting of 5 mol % or less of a long chain diol having weight average molecular weight of 800 to 5,000, a short chain diol having weight average molecular weight of 50 to 500 and/or a short chain diamine and an organic diisocyanate is contained as the binder, said long chain diol has one polar group selected from —COOM, —SO3M, —OSO3M, —OPO(OM)2, or —PO(OM)2 (where M represents a hydrogen atom, an alkali metal ion, or an ammonium ion) in the molecule, and the polar group is contained in the polyurethane by 1 to 5 mol %.
    Type: Grant
    Filed: September 22, 1995
    Date of Patent: April 23, 2002
    Assignee: Fuji Photo Film, Ltd.
    Inventors: Yuichiro Murayama, Masaki Satake, Hiroshi Hashimoto, Tsutomu Okita
  • Patent number: 6376089
    Abstract: The present invention provides a process for producing a rare earth metal-based permanent magnet having, on its surface, a corrosion-resistant film containing inorganic fine particles having a specific average particle size and dispersed in a film phase formed from a silicon compound. In a heat treatment for forming a film by a hydrolyzing reaction and a thermally decomposing reaction of the silicon compound, followed by a polymerizing reaction, a stress is generated within the film by the shrinkage of the film. In the corrosion-resistant film formed by the producing process according to the present invention, however, such stress is dispersed by the presence of the inorganic fine particles and hence, the generation of physical defects such as cracks is inhibited. In addition, voids between the adjacent inorganic fine particles are filled with the film phase formed from the silicon compound and hence, the formed film is dense.
    Type: Grant
    Filed: August 29, 2000
    Date of Patent: April 23, 2002
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Takeshi Nishiuchi, Atsushi Kikugawa, Fumiaki Kikui
  • Patent number: 6376043
    Abstract: An aromatic polyamide film laminate comprising at least two biaxially oriented films formed of an aromatic polyamide, wherein (1) a film layer A, which is the outermost layer of the laminate, contains inorganic particles produced from hydroxides or carbonates of at least one metal of the groups Ia and IIa of the periodic table, the inorganic particles having an average particle diameter of 80 to 1,500 nm, and has a surface roughness (RaA) of 1 to 20 nm, and (2) a film layer B, which is the layer opposite to the layer A of the laminate, has a surface roughness (RaB) of 0.1 to 10 nm, (3) the surface roughness (RaB) of the film layer B being smaller than the surface roughness (RaA) of the film layer A by 1 nm or more.
    Type: Grant
    Filed: March 21, 2000
    Date of Patent: April 23, 2002
    Assignee: Teijin Limited
    Inventors: Makoto Handa, Mitsumasa Ono
  • Patent number: 6376108
    Abstract: This invention is to provide a magnetic head consisting of NiFeMo alloy which assures excellent high frequency characteristic and makes easy formation of magnetic domain structure without any heat treatment and thereby contributes to improvement of magnetic recording capability. Magnetic material for a magnetic head includes Ni, Fe and Mo. The composition ratio of NiFeMo is selected under the condition where Ni is 77 to 82 atom %, Fe is 15 to 21 atom %, Mo is under 6 atom %, and magnetic strain constant &lgr;s is in the range of −1×10−6≦&lgr;s ≦10−6.
    Type: Grant
    Filed: December 14, 1999
    Date of Patent: April 23, 2002
    Assignee: Fujitsu Limited
    Inventors: Mitsuru Otagiri, Sanae Takefusa, Yuko Miyake
  • Publication number: 20020043161
    Abstract: This invention relates to a relatively thin cladded graphic arts impression graphic arts impression die plate (20) having a steel layer (22) which is integral throughout the extent thereof with a layer of copper (24) or bronze. A relieved design-defining surface may be formed in the copper or bronze layer by a chemical etching process or by chemical milling. In the case of chemical etching of the graphic arts impression die plate (20), a design-defining layer of photo-resist is applied to the outer surface of the copper layer (24) or the bronze layer and the relieved design is formed in the copper or bronze layer using a conventional ferric chloride etching solution. The etched graphic arts impression die plate may be mounted on an etchant-resistant backing or magnetic support member (28) to present an assembly which increases the thickness of the die assembly sufficiently to permit use thereof on standard stamping and embossing equipment without modification of the die-supporting chase.
    Type: Application
    Filed: October 24, 2001
    Publication date: April 18, 2002
    Inventors: Glenn E. Hutchison, Todd E. Scholtz
  • Patent number: 6372325
    Abstract: Disclosed is a magnetic recording medium having a flexible nonmagnetic support, a nonmagnetic layer containing a nonmagnetic powder and a binder on the support, and a magnetic layer containing a ferromagnetic powder and a binder. The magnetic layer has an average thickness d of 0.01 to 0.3 &mgr;m, a ratio &sgr;/d of a standard deviation &sgr; in the thickness of the magnetic layer to the average thickness d equal to or less than 0.5, and, according to the roughness spectrum of a magnetic layer surface measured with an atomic force microscope, a PSD of 0.5 nm2 or lower in a wavelength of 1 to 5 &mgr;m and a PSD of 0.02 to 0.5 nm2 in a wavelength of 0.5 &mgr;m or more to less than 1 &mgr;m.
    Type: Grant
    Filed: March 13, 2000
    Date of Patent: April 16, 2002
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Kiyomi Ejiri, Koji Naoe, Masatoshi Takahashi
  • Patent number: 6372338
    Abstract: A particulate magnetic recording media wherein the magnetic particles are substantially spherical. The spherical particle shape makes possible a media which is magnetically isotropic, well dispersed and low in noise, and free of magnetically inferior broken particles.
    Type: Grant
    Filed: November 19, 1998
    Date of Patent: April 16, 2002
    Assignee: Eastman Kodak Company
    Inventors: Frederick J. Jeffers, Bradford D. West, Robert O. James, Frederick R. Chamberlain, IV, Neil Smith, Ronald M. Wexler
  • Patent number: 6368722
    Abstract: A laminated film containing a heat resisting resin layer which is soluble in a dipolar aprotic solvent, is laminated on a biaxially oriented thermoplastic film, wherein the biaxially oriented thermoplastic film and the heat resisting resin layer are directly adhered to each other, and the heat resisting resin is stretched at least in one direction after coating; there is no intervening adhesive layer; the resulting laminated film has excellent adhesion and flatness, and a resin laminated film having high flatness and productivity is provided.
    Type: Grant
    Filed: November 30, 1999
    Date of Patent: April 9, 2002
    Assignee: Toray Industries, Inc.
    Inventors: Takashi Mimura, Akimitsu Tsukuda, Yasushi Takada, Hiroyuki Tanaka
  • Patent number: 6368706
    Abstract: 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: Grant
    Filed: July 8, 1998
    Date of Patent: April 9, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hitoshi Iwasaki, Yuichi Ohsawa, Reiko Kondoh, Susumu Hashimoto, Atsuhito Sawabe, Yuzo Kamiguchi, Masashi Sahashi, Hiromi Fuke
  • Patent number: 6365286
    Abstract: A magnetic element which has a laminate film composed of ferromagnetic-dielectric mixed layer and dielectric layer laminated alternately, said ferromagnetic-dielectric mixed layer being a mixture of a ferromagnetic material having coercive force and a dielectric material, with the volume of the former being equal to or larger than that of the latter. The ferromagnetic-dielectric mixed layer 3 has the ferromagnetic layer 1 which is arranged close thereto with a dielectric layer interposed between them. Tunnel current flows between the ferromagnetic-dielectric mixed layer. The magnetic layer with a smaller coercive force has its spin switched so that the magnetoresistance effect is produced. The magnetic element having a ferromagnetic tunnel junction is designed such that the rate of change in magnetoresistance increases and the resistance of the element decreases and the rate of change in magnetoresistance varies less depending on voltage.
    Type: Grant
    Filed: September 2, 1999
    Date of Patent: April 2, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koichiro Inomata, Yoshiaki Saito, Shinichi Nakamura
  • Patent number: 6361859
    Abstract: A magnetic recording media having a CrMo underlayer provides improved performance characteristics. In one embodiment, the recording media comprises a rigid substrate and an underlayer disposed over the substrate, in which the underlayer comprises CrMo. Preferably, the Mo crystals in the CrMo underlayer are at least about 140 Å in the film growth direction for the 002 crystal plane. Advantageously, recording media with such a 002 crystal size, when used in conjunction with a magnetic layer, such as CoCrTaPtNi, exhibits significantly higher parametric qualities than underlayers using other materials. Typically, Mo in the range between about 7% and 16% in the CrMo alloy, more preferably between about 9% and 11%, will provide the recited 002 crystal size.
    Type: Grant
    Filed: November 20, 2000
    Date of Patent: March 26, 2002
    Assignee: United Modular Corporation
    Inventors: Yuanda Cheng, Xingbo Yang, Yancy Song
  • Patent number: 6361863
    Abstract: A device comprising a magnetoresistive material including a mixture of powdered CrO2 having granules at least partially coated with Cr2O3, and powdered Ni, the mixture being compressed to form a compacted material which exhibits a magnetoresistance ratio of at least 12% at 300° K and 4000 Oe.
    Type: Grant
    Filed: May 17, 1999
    Date of Patent: March 26, 2002
    Assignee: The Research Foundation of State University of New York
    Inventors: Richard J. Gambino, Dongil Shin
  • Patent number: 6358432
    Abstract: A composite magnetic material comprises a ferrite powder and a resin, in which the ferrite powder comprises a cobalt substituted Y type hexagonal ferrite (2BaO.2CoO.6Fe2O3) or cobalt substituted Z type hexagonal ferrite (3BaO.2CoO.12Fe2O3), and the permeability at 2 GHz is 90% or more of that at 1 MHz.
    Type: Grant
    Filed: October 26, 2000
    Date of Patent: March 19, 2002
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Kunisaburo Tomono, Mitsuhiro Fukushima, Hiroshi Marusawa, Takashi Ohsawa, Takashi Toda
  • Patent number: 6358635
    Abstract: A magnetic shielding element for a magnetic recording and sensing device which prevents the problem of pop-corn noise or covariance of amplitude noise in the magnetic sensing device. The shielding element has a layer of antiferromagnetic exchange material formed on a layer of single domain first ferromagnetic material. The single domain first ferromagnetic material is stabilized by the antiferromagnetic exchange material. A layer of non-magnetic metal is then formed on the layer of antiferromagnetic exchange material and a layer of second ferromagnetic material is formed on the layer of non-magnetic metal to complete the shielding element. When the single domains of the first ferromagnetic material are disturbed by the strong magnetic fields of a write cycle they relax with a relaxation time of pico seconds and are fully relaxed before a read cycle begins.
    Type: Grant
    Filed: December 20, 1999
    Date of Patent: March 19, 2002
    Assignee: Headway Technologies, Inc.
    Inventors: Tai Min, Otto Voegeli, Rongfu Xiao, Cherng-Chyi Han, Po-Kang Wang
  • Patent number: 6358619
    Abstract: The present invention is an aromatic polyamide film, which is a laminated film consisting of at least two layers, comprising an aromatic polyamide and 0.1 wt % to 10 wt % of at least one or more different polymers, being contained at least in the outermost layer (layer A) of the film, subject to the condition that the following formulae are satisfied 0.01≦t/d≦0.5 0.05≦s/L≦1 where d is the thickness of the layer A (&mgr;m); t, the circle equivalent diameter of the isles of the different polymer (&mgr;m); L, the major axis of the isles (&mgr;m); and s, the minor axis of the isles (&mgr;m). The aromatic polyamide film of the present invention is especially useful an a base film of a magnetic recording medium with high productivity since it is free from the wrinkling and weaving caused at the time of film winding and excellent in abrasion resistance on the film surface.
    Type: Grant
    Filed: June 22, 1999
    Date of Patent: March 19, 2002
    Assignee: Toray Industries, Inc.
    Inventors: Masanori Sueoka, Mitsuhiro Horiuchi, Akimitsu Tsukuda
  • Patent number: 6358636
    Abstract: Protective overlayers for magnetic recording media are described. The overlayers, composed of a transition metal-silicon or transition metal-germanium interlayer and a carbon overcoat, provide good wear resistance and corrosion resistance at thicknesses of less than 100 Å.
    Type: Grant
    Filed: January 20, 1999
    Date of Patent: March 19, 2002
    Assignee: HMT Technology Corporation
    Inventors: Ming M. Yang, Zhangmin Wang, James L. Chao, Michael A. Russak
  • Patent number: 6355342
    Abstract: High density, multi-layer, magneto-optical (HDMMO) information storage and retrieval media having improved tribological properties when used in high-density storage devices employing very small head flying heights are formed by providing an ultra-thin, protective flash layer overcoat (FLO)/lubricant topcoat layer system over the surface of a HDMO medium comprising a metal superlattice. Embodiments of the present invention include forming the FLO layer of an amorphous, abrasion-resistant, carbon-based, diamond-like material not greater than about 10 Å thick and selected from CNx, CHx, and CNxHy, and providing the lubricant topcoat on the FLO layer as an about 15-25 Å thick layer of a fluoropolyether or perfluoropolyether material, e.g., perfluoropolyethylene (PFPE).
    Type: Grant
    Filed: November 3, 1999
    Date of Patent: March 12, 2002
    Assignee: Seagate Technology LLC
    Inventor: Ga-Lane Chen
  • Patent number: 6352765
    Abstract: A magneto-optical recording medium includes at least a first magnetic layer, a second magnetic layer and a third magnetic layer which are layered in this order, the first magnetic layer being formed of a perpendicularly magnetized film having a relatively small wall coercivity and a relatively large wall mobility compared with the third magnetic layer in the vicinity of a predetermined temperature, and the magneto-optical recording medium satisfies conditions Tc2<Tcomp1<Tc1 and Tc2<Tcomp1<Tc3 where Tcomp1 is a compensation temperature of the first magnetic layer, Tc1, Tc2 and Tc3 are Curie temperatures of the first, second and third magnetic layers, respectively.
    Type: Grant
    Filed: December 10, 1999
    Date of Patent: March 5, 2002
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Noboru Iwata, Junji Hirokane
  • Patent number: 6352776
    Abstract: A magnetic recording medium of the present invention comprises: a non-magnetic base film; a non-magnetic undercoat layer formed on the non-magnetic base film, comprising a binder resin and non-magnetic acicular black iron-based composite particles; and a magnetic coating film comprising a binder resin and magnetic particles, the non-magnetic acicular black iron-based composite particles comprising: acicular hematite particles or acicular iron oxide hydroxide particles (core particles) having an average major axis diameter of 0.01 to 0.3 &mgr;m; a coating layer formed on the surface of the particles, comprising a specific organosilicon compound; and a carbon black coat composed of at least two carbon black layers integrally formed on the coating layer, adhered with each other through an adhesive on the coating layer.
    Type: Grant
    Filed: August 2, 2000
    Date of Patent: March 5, 2002
    Assignee: Toda Kogyo Corporation
    Inventors: Kazuyuki Hayashi, Keisuke Iwasaki, Yasuyuki Tanaka, Hiroko Morii
  • Patent number: 6348274
    Abstract: A magnetoresistive element includes a pinned layer, free layer and non-magnetic spacer film between them. The pinned layer is made up of a first ferromagnetic metal layer, first non-metal layer on the first ferromagnetic metal layer, second non-metal layer on the first non-metal layer and different in composition from the first non-metal layer, and second ferromagnetic metal layer on the second non-metal layer. Thus, the magnetoresistive element, which may be used in a magnetic head of a magnetic recording apparatus, ensures a good bias property of the pinned film while maintaining a large MR changing rate of a specular spin valve structure, and it is simultaneously improved in soft magnetic property.
    Type: Grant
    Filed: December 27, 1999
    Date of Patent: February 19, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yuzo Kamiguchi, Hiromi Yuasa, Masashi Sahashi, Hitoshi Iwasaki
  • Patent number: 6348252
    Abstract: A fastening component of a separable fastener has some portion that is necessary for its fastening function, such as the hooks, the base to which the hooks are attached or a substrate that is used for another purpose, comprised of a magnetically attractive constituent. Another portion of the fastening component is comprised of a magnetically inert constituent. The fastening element may be the hook portion or the loop portion of a typical fastener. The fastening elements and the base may be unitary, or of different precursors, such as in a woven fastener component. The magnetically inert constituent may comprise a polymeric plastic or a thermoplastic elastomer. The magnetic attractant may impregnate the magnetically inert constituent, or it may coat or be coated by the magnetically inert constituent. The magnetic attractant may comprise a metal powder. The metal may be selected from the group consisting of iron powder. The magnetic attractant may be an organo-iron or a rare earth metal.
    Type: Grant
    Filed: October 6, 2000
    Date of Patent: February 19, 2002
    Assignee: Velcro Industries B.V.
    Inventors: Randall B. Kenney, Brian J. Routhier, Martin I. Jacobs
  • Patent number: 6348275
    Abstract: A bulk amorphous metal magnetic component has a plurality of layers of ferromagnetic amorphous metal strips laminated together to form a generally three-dimensional part having the shape of a polyhedron. The bulk amorphous metal magnetic component may include an arcuate surface, and preferably includes two arcuate surfaces that are disposed opposite each other. The magnetic component is operable at frequencies ranging from between approximately 50 Hz and 20,000 Hz. When the component is excited at an excitation frequency “f” to a peak induction level Bmax, it exhibits a core-loss less than “L” wherein L is given by the formula L=0.0074 f (Bmax)1.3+0.000282 f1.5(Bmax)2.4, said core loss, said excitation frequency and said peak induction level being measured in watts per kilogram, hertz, and teslas, respectively.
    Type: Grant
    Filed: April 6, 2000
    Date of Patent: February 19, 2002
    Assignee: Honeywell International Inc.
    Inventors: Nicholas John DeCristofaro, Peter Joseph Stamatis, Gordon Edward Fish
  • Patent number: 6348266
    Abstract: A magnetic recording medium including a lubricant topcoat having increased bonding to the medium surface comprises an amphiphilic lubricant molecule having a hydrophilic central portion including a plurality of polar functional groups bound to the medium surface and a pair hydrophobic fluoroalkyl ether or perfluoroalkylether end portions at respective ends of the hydrophilic central portion and extending away from the medium surface.
    Type: Grant
    Filed: August 31, 1999
    Date of Patent: February 19, 2002
    Assignee: Seagate Technology LLC
    Inventors: Youmin Liu, Vidya Gubbi, Chung Shih
  • Publication number: 20020018916
    Abstract: A magnetic thin film of the present invention comprises: a substrate; and a ferromagnetic film being formed on the substrate and having an average diameter of 0.1 to 10 &mgr;m, a thickness of 0.005 to 1.5 &mgr;m and a ratio of the thickness to the average diameter of not more than 0.5:1, wherein the ferromagnetic film having at a center portion thereof a perpendicular magnetization component, which is oriented or magnetized in the up or down direction perpendicular to the surface of the magnetic thin film.
    Type: Application
    Filed: March 14, 2001
    Publication date: February 14, 2002
    Inventor: Teruya Shinjo
  • Patent number: 6346337
    Abstract: A bulk amorphous metal magnetic component has a plurality of layers of amorphous metal strips laminated together to form a generally three-dimensional part having the shape of a polyhedron. The bulk amorphous metal magnetic component may include an arcuate surface, and preferably includes two arcuate surfaces that are disposed opposite each other. The magnetic component is operable at frequencies ranging from between approximately 50 Hz and 20,000 Hz. When the component is excited at an excitation frequency “f” to a peak induction level Bmax, it exhibits a core-loss less than “L” wherein L is given by the formula L=0.0074 f (Bmax)1.3+0.000282 f1.5 (Bmax)2.4, said core loss, said excitation frequency and said peak induction level being measured in watts per kilogram, hertz, and teslas, respectively.
    Type: Grant
    Filed: January 5, 2000
    Date of Patent: February 12, 2002
    Assignee: Honeywell International Inc.
    Inventors: Nicholas John DeCristofaro, Peter Joseph Stamatis, Gordon Edward Fish
  • Patent number: 6346322
    Abstract: A magneto-optical recording medium includes at least a first magnetic layer, a second magnetic layer, a third magnetic layer, a non-magnetic intermediate layer and a fourth magnetic layer which are layered in this order, the first magnetic layer being formed of a perpendicularly magnetized film having a relatively small wall coercivity and a relatively large wall mobility compared with the third magnetic layer in the vicinity of a predetermined temperature, the second magnetic layer being formed of a magnetic film whose Curie temperature is lower than the Curie temperatures of the first magnetic layer and third magnetic layer, the fourth magnetic layer being a perpendicularly magnetized film with a uniform magnetization direction and forming a region having a uniform magnetization direction in the first magnetic layer by magnetostatic coupling with the first magnetic layer when the second magnetic layer is heated to a predetermined temperature or a higher temperature.
    Type: Grant
    Filed: December 7, 1999
    Date of Patent: February 12, 2002
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Noboru Iwata, Junji Hirokane
  • Patent number: 6346336
    Abstract: A soft magnetic film and a soft magnetic multilayer film of high saturation magnetization having an excellent soft magnetic property and a magnetic device use the same by providing an Fe—N thin film 2 formed on a substrate 1 with a configuration such that the main phases are &agr;-Fe and &ggr;′-Fe4N, the crystal grain sizes of the &agr;-Fe phase and the &ggr;′-Fe4N phase are reduced to as fine as not more than 10 nm, the spacings of the lattice plane (110) of &agr;-Fe parallel to the film surface and the lattice plane (200) of &ggr;′-Fe4N are expanded compared to those in the condition where there is no lattice strain, and the spacing of the lattice plane (111) of &ggr;′-Fe4N is contracted compared to that in the condition where there is no lattice strain.
    Type: Grant
    Filed: May 21, 1999
    Date of Patent: February 12, 2002
    Assignee: Matsushita Electrical Industrial Co., Ltd.
    Inventor: Kumio Nago
  • Patent number: 6346310
    Abstract: Disclosed is a magnetic recording medium comprising a magnetic layer on a surface of a flexible support and a backcoat layer on the opposite surface, characterized in that the backcoat layer comprises a granulated oxide consisting of titanium oxide, &agr;-iron oxide or a mixture thereof and carbon black in the weight ratio ranging from 60/40 to 90/10, and further comprises a binder in an amount ranging from 10 to 40 parts by weight with respect to 100 parts by weight of the total amount of the granulated oxide and carbon black. The magnetic recording medium of the present invention is characterized in that both the running durability and electromagnetic characteristics are excellent.
    Type: Grant
    Filed: December 19, 2000
    Date of Patent: February 12, 2002
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Koji Naoe, Tatsuo Ishikawa, Hiroaki Takano
  • Patent number: 6344257
    Abstract: An aromatic polyamide film for a high-density magnetic recording medium which has excellent electromagnetic conversion characteristics and few drop outs even when it is used as a base film for a deposited metal thin film magnetic recording medium and enables the production of a large-capacity magnetic recording medium. An aromatic polyamide film for a high-density magnetic recording medium which has surface flatness and excellent transferability, is thereby useful as a base film especially for a high-density magnetic recording medium and can satisfy contradictory requirements, that is, the prevention of a trouble such as projection of protrusions in a calendering step and winding easiness at the same time.
    Type: Grant
    Filed: December 13, 1999
    Date of Patent: February 5, 2002
    Assignee: Teijin Limited
    Inventors: Makoto Handa, Mitsumasa Ono, Takeo Asai
  • Patent number: 6342311
    Abstract: A magnetic recording head has a magnetic pole tip and a seed layer upon which the magnetic pole tip is formed. The seed layer is preferably formed of a high magnetic moment material having a saturation magnetization of at least 1.8 Tesla and a high resistance to corrosion. In preferred embodiments of the present invention, the seed layer is preferably formed of 2.1 Tesla Fe44-46Co39-41Ni14.5-15, 1.8 Tesla Fe54-56Ni27-29Co16-18 Tesla Fe86-90Cr10-14, or 1.9 Tesla Fe52-62Co26-36Cr10-14, wherein the subscripts indicate a preferred range of atomic percentages for each element in the given alloy.
    Type: Grant
    Filed: June 6, 2000
    Date of Patent: January 29, 2002
    Assignee: Seagate Technology, Inc.
    Inventors: Venkateswara R. Inturi, Martin L. Plumer, Charles H. Tolman, Steve Riemer, Ibro Tabakovic, Steven B. Slade
  • Publication number: 20020009568
    Abstract: An adhesive tape construction is removable from one or more objects to which it is adhered and which is reusably separable within its construction so that an object can be separated from another and subsequently reconnected with one another. The adhesive tape construction can be used to bond the other opposed surfaces of objects, including rigid objects such as a picture frame to a wall, where no portion of the adhesive tape construction projects from between the objects, and which subsequently affords easy separation of the objects without damage to either of them. More specifically, the adhesive tape construction includes a stretch release adhesive tape structure combined with a reusable connector surface.
    Type: Application
    Filed: May 7, 2001
    Publication date: January 24, 2002
    Inventors: James L. Bries, Michael D. Hamerski
  • Patent number: 6340520
    Abstract: A giant magnetoresistive material film includes at least two ferromagnetic layers of a NiFe alloy or NiFeCo alloy, which are formed on a substrate through a nonmagnetic layer of Au, Ag, Cu or Cr, wherein magnetization of at lest one of the ferromagnetic layers is pinned by a coercive force increasing layer of &agr;-Fe2O3 provided adjacent thereto and having a thickness of 200 to 1000 Å so as to increase coercive force of the ferromagnetic layer, and the other ferromagnetic layer has free magnetization so as to produce a change in resistance at a low magnetic field. The present invention also provides a method of producing the giant magnetoresistive material film and a magnetic head provided with the giant magnetoresistive material film.
    Type: Grant
    Filed: April 2, 1998
    Date of Patent: January 22, 2002
    Assignee: Alps Electric Co., Ltd.
    Inventors: Fumihito Koike, Naoya Hasegawa