Patents Examined by William M. Atkinson
  • Patent number: 4818595
    Abstract: A novel, non-combustible thin coating, applied as an air-setting paint, is used to form a coherent fire-barrier on or between susceptible wood or plastic substrates, or other substances. Consisting of a paint-like slurry of three separate but compatible and mutually synergistic co-bonding systems, viz. magnesium "oxychloride" cement, plus high alumina mono-calcium aluminate cement, plus colloidal silica dispersed in dimethyl formamide (DMF), and utilizing an aqueous solution of magnesium chloride as the common hydrating fluid for the two cements, the coating retains its structural integrity through prolonged exposure to flame temperatures of F. The coating takes advantage of its brilliant whiteness to act as a thermal radiation reflector for the high radiation component of most flames.
    Type: Grant
    Filed: April 24, 1987
    Date of Patent: April 4, 1989
    Assignee: Delphic Research Laboratories, Inc.
    Inventor: Harold Ellis
  • Patent number: 4788092
    Abstract: The present invention provides a disc-shaped magnetic recording medium particularly suitable for high density recording obtainable a high output power with low noise. In the disc-shaped magnetic recording medium according to the present invention, a ferromag netic powder having a coercive force of about 1,000 Oe or higher and a BET specific surface area in the range from about 25 to 70 m.sup.2 /g is employed. This allows a decrease in noise level and satisfies the electromagnetic performance requirements for high density recording. A random (unoriented) orientation or a circumferential orientation of the ferromagnetic powder in the magnetic layer provides high output power without causing a variation in output power.
    Type: Grant
    Filed: September 9, 1983
    Date of Patent: November 29, 1988
    Assignee: Sony Corporation
    Inventors: Ryoji Chubachi, Yoshihisa Kawamura, Nobuyuki Nihei
  • Patent number: 4788095
    Abstract: This invention provides a metal oxide magnetic substance represented by the following general formula:MeO.n[Ma.sub.x Mb.sub.y Co.sub.z Fe.sub.2-(x+m/3y+2/3z) O.sub.3 ][wherein, Me, Ma, Mb, x, y, z, m and n are each as mentioned below.Me: at least one divalent metal selected from the group consisting of Ba, Sr and Pb,Ma: at least one trivalent metal selected from the group consisting of Ga, Al, Cr and Rh,Mb: at least one divalent to tetravalent metal selected from the group consisting of Zn (divalent); Ni, In, Sc, Cr, Sb, Bi, Y and Sm (trivalent), and Mo, Ti, Sn, Ta, V, Mn, Ir, Hf, Pd, Nb, Re, Pt, Os, Zr, Tc, Rh, Ge, Ru, W, Te, Pr and Ce (tetravalent) wherein, the metal represented by Mb is not the same as that represented by Me or Ma)x: 0<x.ltoreq.0.5y: 0<y.ltoreq.0.5z: 0<z.ltoreq.0.5 (wherein, 0<x+y+z.ltoreq.1)m: an ionic valency of Mbn: 5.ltoreq.n.ltoreq.
    Type: Grant
    Filed: September 14, 1987
    Date of Patent: November 29, 1988
    Assignee: Ricoh Company, Ltd.
    Inventors: Hazime Machida, Hitoshi Nakamura, Fumiya Omi, Atsuyuki Watada, Yuziro Kaneko
  • Patent number: 4786553
    Abstract: A magnetic recording medium comprises a non-magnetic substrate and a thin magnetic film, the thin magnetic film being composed mainly of Co, Ni and at least one of Zr and Hf, and a concentration of Zr, Hf or Zr and Hf as contained in the thin magnetic film being 0.1 to 30% by atom on the basis of the total of Co and Ni, and has a considerably higher corrosion resistance than that of the conventional magnetic recording medium having a thin Co-Ni magnetic film.
    Type: Grant
    Filed: March 27, 1987
    Date of Patent: November 22, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Yoshihiro Shiroishi, Sadao Hishiyama, Hiroyuki Suzuki, Norikazu Tsumita, Tsuneo Suganuma, Yoshio Gobara, Masaaki Hayashi, Makoto Sano, Takaaki Shirakura
  • Patent number: 4786564
    Abstract: A method for manufacturing a disk includes the step of forming a first nickel-phosphorus alloy layer on an aluminum substrate, e.g., by electroless plating. A second nickel-phosphorus layer is then sputtered onto the first nickel-phosphorus layer, and a magnetic alloy is sputtered onto the second nickel-phosphorus layer. The magnetic alloy is typically sputtered immediately after the second nickel-phosphorus layer is formed without removing the disk from the sputtering apparatus between the time the second nickel-phosphorus layer is formed and the time the magnetic alloy is formed. Because of this, contaminants are not capable of lodging on or affecting the surface of the disk prior to formation of the magnetic alloy. The second nickel-phosphorus layer is typically amorphous and therefore masks any nonuniformities in the surface of the first nickel-phosphorus layer.
    Type: Grant
    Filed: February 25, 1987
    Date of Patent: November 22, 1988
    Assignee: Komag, Inc.
    Inventors: Tu Chen, Tsutomu T. Yamashita
  • Patent number: 4780377
    Abstract: A magneto-optical recording medium in the form of a thin amorphous alloy film having the following composition of Gd-Nd-M-Fe (M: at least one of Dy and Ho), has an axis of easy magnetization in a direction perpendicular to the surface of the film. The M density is at least sufficient to keep the Curie point below C.
    Type: Grant
    Filed: May 5, 1987
    Date of Patent: October 25, 1988
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Satoshi Takano
  • Patent number: 4777082
    Abstract: In an optical recording medium comprising a substrate and a recording layer thin film comprised of a rare earth element and a transition metal, for example, TbFeCo on the substrate, a metal thin film layer having a high magnetic permeability, for example, Permalloy is formed on the recording layer. A transparent dielectric film layer may be formed between the substrate and the recording layer thin film.
    Type: Grant
    Filed: August 17, 1987
    Date of Patent: October 11, 1988
    Assignee: TDK Corporation
    Inventors: Hideki Ishizaki, Takayoshi Kobuke, Suguru Takayama
  • Patent number: 4777068
    Abstract: In an optical recording medium having an optical recording layer provided on a substrate, a carbide film of a substance selected from among tungsten, boron, molybdenum, hafnium, niobium, titanium, chromium, vanadium, tantalum and silicon is formed on one or each side of the recording layer.
    Type: Grant
    Filed: August 5, 1985
    Date of Patent: October 11, 1988
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hiroshi Omata, Shigeharu Iijima, Eizo Sasamori, Katsuhiko Takano, Masaaki Matsushima, Kazuoki Honguu, Mitsuharu Sawamura, Kazuhiko Kikuchi, Takahiko Ishiwatari, Hiroyoshi Kishi, Hisaaki Kawade
  • Patent number: 4775576
    Abstract: A substrate for perpendicular anisotropic magnetic recording comprises a nonmagnetic substrate (SUBSI) on which a thin metal magnetic medium (CMI) having a negative magnetostrictive effect is deposited. The direction of easy magnetization of the medium is perpendicular to the surface. In order to minimize the magnetostrictive effect in the metal magnetic medium, the medium comprises a stack of alternate thin magnetic and nonmagnetic layers (CI.sub.1 -CI.sub.n, ISO.sub.1 -ISO.sub.n-1), the nonmagnetic layers (ISO.sub.1 -ISO.sub.n-1) being sufficiently flexible so as to dampen the effect of the strains in the magnetic layers and enable strong magnetic coupling between them. The thickness of the nonmagnetic layers is between 150 and 250 angstroms, while the thickness of the magnetic layers is between 700 and 2000 angstroms. The stack may include as many as 10 or more magnetic layers of a chrome/cobalt alloy. The nonmagnetic layers may be SiO, SiO.sub.2 and mixtures thereof.
    Type: Grant
    Filed: July 14, 1986
    Date of Patent: October 4, 1988
    Assignee: Bull S.A.
    Inventors: Jean-Claude Bouchand, Jacques Desserre, Dominque Jeanniot
  • Patent number: 4775603
    Abstract: An optical-magnetic recording medium utilizing a recording layer of an amorphous rare-earth-transition metal alloy so as to rely on the Kerr effect. An enhancing layer of ZnS and a fluoride of an alkaline-earth metal (preferably CaF.sub.2) is deposited on a grooved substrate and the recording layer deposited thereover to both enhance the Kerr effect and prevent peeling.
    Type: Grant
    Filed: June 29, 1987
    Date of Patent: October 4, 1988
    Assignee: Pioneer Electronic Corporation
    Inventor: Seiro Fujii
  • Patent number: 4769282
    Abstract: A magnetic recording medium comprising a non-magnetic substrate and a magnetic layer formed on the substrate, in which the magnetic layer comprises 1-8% metal element M consisting of one or more of B, Al, Si, P, Ge, Sn, Sb, Se, Te, Pb, Bi, Cu, Ti, V, Cr, Zr, Nb, Mo, W and Ta, less than 13% by weight of one or more of rare earth elements of Y, La, Ce, Pr, Nd, Sm, Gd, Tb, or Dy, 3-13% by weight of oxygen, balance of Co and inevitable impurities. The magnetic layer may contain less than 22% by weight of Ni. The magnetic recording medium has a favorable corrosion resistance and excellent magnetic properties.
    Type: Grant
    Filed: February 20, 1987
    Date of Patent: September 6, 1988
    Assignee: Sumitomo Metal Mining Co., Ltd.
    Inventors: Junya Tada, Tomohisa Watanabe, Makoto Akihiro, Kouichi Oka, Takehiko Sato
  • Patent number: 4766039
    Abstract: A magnetic head comprising a magnetic film in at least a part of a magnetic circuit, at least a part of the magnetic film being formed in contact with, or being exposed to, an oxide or oxygen at least in a heating step at C. or higher in a process for preparing the magnetic head is disclosed. An amorphous alloy film for the magnetic film has the following composition formula to give distinguished head characteristics without any oxidation:Co.sub.a T.sub.b Zr.sub.c N.sub.dwhere T is at last one of Nb, Ta, W, Mo, V and Cr; N is at least one of Au, Pt and Ag; d.gtoreq.1, b>0, b.sub.1 +b.sub.2 +2c.gtoreq.10, a+d.gtoreq.80, -1.ltoreq.(3c-b.sub.1 -3b.sub.2 -5b.sub.3 -3b.sub.4 -4d)/(c+b.sub.1 +b.sub.2 +b.sub.3 +b.sub.4 +d).ltoreq.1, and a+b+c+d=100, where b.sub.1 is a Nb concentration, b.sub.2 is a Ta concentration, b.sub.3 is a W concentration, b.sub.4 is sum total of Mo, Cr and V concentrations and b=b.sub.1 +b.sub.2 +b.sub.3 +b.sub.4.
    Type: Grant
    Filed: June 17, 1986
    Date of Patent: August 23, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Shigekazu Otomo, Noriyuki Kumasaka, Noritoshi Saito, Takeo Yamashita, Kazuo Shiiki, Yoshihiro Hamakawa
  • Patent number: 4766034
    Abstract: A magnetic recording medium comprising a magnetic metal layer on a substrate. The uppermost layer of the magnetic metal layer consists essentially of a mixture of a magnetic metal such as Co or Co-Ni alloy and an oxide thereof. The surface portion of the magnetic layer consists essentially of a crystal phrase of said oxide and the ratio of oxide forming metallic atoms decreases continuously with the depth from the outer surface.
    Type: Grant
    Filed: December 14, 1987
    Date of Patent: August 23, 1988
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Toshihiko Sato, Takeshi Kitamura, Shinsaku Nagaoka
  • Patent number: 4764436
    Abstract: A thin film according to the present invention which is disclosed herein is an iron and oxygen based perpendicular magnetized anisotropic thin film useful as a magnetic recording material. This thin film has an excellent magnetic anisotropy in the perpendicular direction to the surface thereof and comprises iron (Fe)-oxygen(O) system, and tin (Sn) and/or germanium (Ge) or aluminum (Al) as a third element. The specified examples of such thin films include those having the composition represented by (I) Fe.sub.x O.sub.y M.sub.z wherein M represents Sn and/or Ge, and (II) Fe.sub.x O.sub.y Al.sub.z.The thin film has characteristics optimum as a uniform perpendicular magnetic recording medium, thus making it possible to provide a fine and high-density recording.
    Type: Grant
    Filed: May 16, 1986
    Date of Patent: August 16, 1988
    Assignee: Research Development Corporation of Japan
    Inventors: Nakao Akutsu, Masako Akimitsu, Tadashi Mizoguchi
  • Patent number: 4758474
    Abstract: Herein is disclosed a magnetic recording member having a high mechanical durability and an improved resistance to wear. The magnetic recording member comprises a substrate, a magnetic layer formed on the surface of the substrate and a first non-magnetic layer of a metal having a low melting point, preferably lower than C. and formed on the magnetic layer, at least the surface of the first non-magnetic layer being oxidized. The magnetic recording member may further contain a lubricant layer.The surface of the magnetic recording member of the invention presents a roughness lower than 25 nm and includes fine protrusions having a linear density higher than 1.times.10.sup.3 /mm.The process for the preparation of the magnetic recording member is also disclosed.
    Type: Grant
    Filed: November 20, 1986
    Date of Patent: July 19, 1988
    Assignee: Nec Corporation
    Inventor: Yuji Tsukamoto
  • Patent number: 4751124
    Abstract: An information recording medium such as a magneto-optical recording medium is disclosed. The medium comprises two pieces of recording elements. Each element comprises a support and a recording layer provided on a part of one surface of the support. The two pieces of the elements adhere to each other by a non-corrosion-causing adhesive provided on a part of said surface where a recording layer is provided and a fast-hardening adhesive provided on a part of the surface where no recording layer is provided. The time required to adhere the two pieces of the elements can be considerably decreased and the corrosion of the recording layer by the adhesive can be avoided.
    Type: Grant
    Filed: February 13, 1987
    Date of Patent: June 14, 1988
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Takahiro Matsuzawa, Katsuyuki Takeda, Hiromichi Enomoto, Yoshitaka Takahashi, Shozo Ishibashi
  • Patent number: 4751142
    Abstract: Disclosed is a magneto-optical recording element comprising a magnetic film composed of an alloy having a composition represented by the following formula:(Gd.sub.y Dy.sub.1-y).sub.x Fe.sub.1-x (0.15.ltoreq.x.ltoreq.0.35 and 0.30.ltoreq.y.ltoreq.0.95)This magnetic film is characterized in that the nuclear magnetic field, coercive force and saturation magnetic filed in the Kerr hysteresis loop are substantially same at temperatures higher than C.
    Type: Grant
    Filed: September 17, 1986
    Date of Patent: June 14, 1988
    Assignee: Kyocera Corporation
    Inventors: Hisao Arimune, Mitsuo Miyazaki, Takashi Maeda
  • Patent number: 4749628
    Abstract: A vertical magnetic recording medium is formed of multiple layers, each layer comprising a cobalt-platinum (CoPt) magnetic film formed on a hexagonal-close-packed (HCP) necleating film. The thickness of each CoPt film in each layer is sufficiently thin to assure that the film has perpendicular magnetic anisotropy. The magnetic properties of the multilayered magnetic film structure can be varied by varying the thickness of the individual films and the number of layers.
    Type: Grant
    Filed: April 29, 1986
    Date of Patent: June 7, 1988
    Assignee: International Business Machines Corporation
    Inventors: Richard H. Ahlert, James K. Howard, Grace S. Lim
  • Patent number: 4748090
    Abstract: A magnetic recording medium is described, comprising a non-magnetic support base having positioned thereon a magnetic layer and optionally a non-magnetic layer, wherein at least one layer of the magnetic and non-magnetic layers contains an oxyfatty acid ester. This recording medium has superior surface properties and thus superior running properties, and can be satisfactorily used in tape decks.
    Type: Grant
    Filed: August 2, 1983
    Date of Patent: May 31, 1988
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Nobuyuki Yamamoto, Katsumi Ryoke, Nobuo Tsuji, Yuzo Higaki, Toshihisa Okamura
  • Patent number: 4745005
    Abstract: A vertical magnetization recording medium is formed on a high polymer film substrate by vacuum deposition of Co-Cr film or deposition of Co-Cr film with preceding deposition of permalloy film, both with Ti-vacuum deposited interface film on the substrate face, whereby vertical orientation of the C-axis of Co-Cr film with respect to the film surface is easily obtainable, thereby assuring good characteristic as vertical magnetization recording medium.
    Type: Grant
    Filed: May 1, 1985
    Date of Patent: May 17, 1988
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Ryuji Sugita, Toshiaki Kunieda