Patents Examined by Dennis V. Carmen
  • Patent number: 5057374
    Abstract: Nonmagnetic substrate material containing 67 to about 89.9 mol % of MnO, 10 to 33 mol % of NiO, and at least 0.1 mol % but not more than 10 mol % of a material selected from the group of CaO, ZrO.sub.2, V.sub.2 O.sub.5, Y.sub.2 O.sub.3, and Cu and having a rock salt-type crystalline structure.
    Type: Grant
    Filed: September 15, 1988
    Date of Patent: October 15, 1991
    Assignee: Hitachi Metals, Ltd.
    Inventors: Kazuhiro Tsuchiya, Toshikazu Nishiyama, Hiroshi Tomishima
  • Patent number: 5047296
    Abstract: The composite material comprises an alternation of amorphous magnetic material films based on cobalt, niobium and zirconium and electrically insulating material films (4), each magnetic film being formed from several blocks (6) separated from one another by electrically insulating joints (8), the total volume (Vp) occupied by the magnetic blocks and the total volume (Vj) occupied by the insulating joints being such that the ratio (Vp/Vj) varies between 10 and 50. This material can be used in a wide range of applications with electromagnetic fields having a frequency between 50 MHz and several GHz.
    Type: Grant
    Filed: September 8, 1988
    Date of Patent: September 10, 1991
    Assignee: Commissariat a l'Energie Atomique
    Inventors: Bernard Miltenberger, Jean M. Sajer
  • Patent number: 5043231
    Abstract: A gadolinium-lutetium-gallium garnet crystal having the formula:(Gd.sub.1-x Lu.sub.x).sub.3 (Gd.sub.y Lu.sub.z Ga.sub.1-y-z).sub.z Ga.sub.3 O.sub.12 (I)wherein x, y and z are number satisfying 0.ltoreq.x.ltoreq.0.4, 0.ltoreq.y.ltoreq.0.05 and 0.6.ltoreq.z.ltoreq.1.0, respectively.
    Type: Grant
    Filed: October 31, 1989
    Date of Patent: August 27, 1991
    Assignee: National Institute for Research in Inorganic Materials
    Inventors: Yasuto Miyazawa, Nobuhiro Kodama, Kouichi Koudu, Shin-ichi Hanita, Hiroaki Toshima, Shigeyuki Kimura
  • Patent number: 5032470
    Abstract: In accordance with the present invention, there are provided information recording media having a substrate and thereon a recording layer, and a metallic layer composed of an aluminum alloy containing at least hafnium. The information recording media provided are excellent in corrosion resistance and also small in dependence of the recording power on linear velocity.
    Type: Grant
    Filed: April 13, 1990
    Date of Patent: July 16, 1991
    Assignee: Mitsui Petrochemical Industries, Ltd.
    Inventors: Kiyotaka Shindo, Koichi Igarashi, Kunihiko Mizumoto, Hidehiko Hashimoto
  • Patent number: 4999260
    Abstract: A magneto-optical recording medium having at least one of a transition metal and a rare earth metal dispersed in a dielectric material and having an easy axis of magnetization normal to a film plane.
    Type: Grant
    Filed: September 21, 1988
    Date of Patent: March 12, 1991
    Assignee: Canon Kabushiki Kaisha
    Inventors: Ichiro Saito, Yoichi Osato, Eiichi Fujii, Kozo Arao
  • Patent number: 4992338
    Abstract: A multilayer, direct-overwrite, magneto-optic recording elment comprises first and second layers of magnetic materials having different magnetic coercivities and Curie temperatures. Such layers are spaced apart by an intermediate layer comprising a readily polarizable non-magnetic metal. The intermediate layer serves to control the degree of magnetic exchange interaction between the magnetic layers, and prevents the constituents of the magnetic layers from diffusing between such layers.
    Type: Grant
    Filed: March 5, 1990
    Date of Patent: February 12, 1991
    Assignee: Eastman Kodak Company
    Inventors: Tukaram K. Hatwar, Douglas G. Stinson
  • Patent number: 4975339
    Abstract: A magneto-optical recording medium comprises a transparent substrate, a magneto-optical recording layer formed on the transparent substrate and containing a rare earth metal-transition metal alloy, and a thin film containing at least either one of platinum and palladium and formed at least on one surface of the magneto-optical recording layer. Or, the magneto-optical recording medium comprises the transparent substrate, and a magneto-optical recording layer formed on the transparent substrate by alternately overlaying a plurality of thin layers containing a rare earth metal-transition metal alloy, and a plurality of thin layers containing at least either one of platinum and palladium.
    Type: Grant
    Filed: September 16, 1988
    Date of Patent: December 4, 1990
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Takashi Yamada, Masaaki Nomura, Ryoichi Yamamoto, Akira Nahara
  • Patent number: 4957825
    Abstract: A magnetic recording medium comprising a substrate, a ferromagnetic thin film formed on the substrate, and a protective film formed directly on the ferromagnetic thin film, and a process for producing such magnetic recording medium. The expression "formed directly" refers to the technique for forming the protective film on the ferromagnetic thin film so that the interface therebetween is free from contamination by, for instance, conducting the protective film formation under the vacuum used when forming the ferromagnetic thin film.
    Type: Grant
    Filed: January 27, 1988
    Date of Patent: September 18, 1990
    Assignees: Hitachi, Ltd., Hitachi Maxell, Ltd.
    Inventors: Masaaki Futamoto, Yukio Honda, Seiichi Asada, Takashi Nishimura, Kazuetsu Yoshida, Heigo Ishihara
  • Patent number: 4956243
    Abstract: An optical memory element contains first and second reflector films, wherein the first reflector film is made of a material of a sufficiently large light reflectance in a relative sense as compared to the second reflector film, and the second reflector film being made of a material of a sufficiently small thermal conductivity in a relative sense as compared to the first reflector film.
    Type: Grant
    Filed: January 30, 1987
    Date of Patent: September 11, 1990
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tomoyuki Miyake, Yoshiteru Murakami, Hiroyuki Katayama, Akira Takahashi, Kenji Ohta
  • Patent number: 4950547
    Abstract: A magneto-optical recording medium includes one selected from a compound of strontium titanate (SrTiOx), a compound of barium titanate (BaTiOx), a nitrogen compound of strontium titanate (SrTiOxNy), and a nitrogen compound of barium titanate (BaTiOxNy). The magneto-optical recording medium has a large value for the refractive index n and a small value for the extinction coefficient k; moreover, the medium is resistive against corrosions. For the magneto-optical recording medium, there is produced a protective film by simultaneously sputtering a film forming target and a composition adjusting target. The deposition of the protective film is achieved in a mixed atmosphere of an inert gas and oxygen or in a mixed gas of an inert gas and nitrogen.
    Type: Grant
    Filed: July 7, 1989
    Date of Patent: August 21, 1990
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Yoshinori Maeno, Masanobu Kobayashi, Kayoko Oishi
  • Patent number: 4950556
    Abstract: A method for producing a magneto-optic layer includes depositing amorphous magnetizable film layer on a substrate using a triode sputtering process. The magneto-optic layer includes an alloy of terbium, cobalt, iron, chromium and an oxygen content approximately between 2-6 atom percent midway through the thickness of the layer.
    Type: Grant
    Filed: October 26, 1987
    Date of Patent: August 21, 1990
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Richard F. Willson, Vaughn W. Halling
  • Patent number: 4935290
    Abstract: This heat-superstabilized semi-finished product containing thermoplastic resin is constituted of at least two layers: at least one surface layer S designed to be exposed to a source of heat and at least one other layer C which is not directly exposed to said source of heat, said layer S having an overall content by weight of stabilizer which is between 3 and 30 times greater than that of layer C, and said layer S having a surface density between 50 and 600 g.m..sup.-2.
    Type: Grant
    Filed: August 18, 1987
    Date of Patent: June 19, 1990
    Inventors: Hubert de Rancourt, Xavier Gambert
  • Patent number: 4920007
    Abstract: An optical recording medium including an opto-magnetic recording medium is provided with a protective layer of an oxide-nitride mixture on either one side or both sides of the optical recording layer. Because of the provision of the mixture layer, the optical recording layer not only has an improved durability such as a corrosion resistance but also can have improved writing and reading efficiencies through adjustment of the refractive index of the mixture layer.
    Type: Grant
    Filed: September 12, 1988
    Date of Patent: April 24, 1990
    Assignee: Canon Kabushiki Kaisha
    Inventors: Mitsuharu Sawamura, Kazuoki Hongu, Kazuhiko Kikuchi
  • Patent number: 4920013
    Abstract: A magnetic multilayer structure having an increased permeability and an increased saturation magnetic flux density comprises a plurality of magnetic layers and a plurality of intermediate layers alternately laminated one upon another. Each of the magnetic layers is made of Fe, Co, Ni or an alloy containing one of Fe, Co and Ni, while each of the intermediate layers is made of a material capable of interstitially forming a solid solution with the material of the magnetic layers.
    Type: Grant
    Filed: September 23, 1987
    Date of Patent: April 24, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Toshio Kobayashi, Shigekazu Otomo, Ryoichi Nakatani, Noriyuki Kumasaka
  • Patent number: 4911997
    Abstract: A magnetic recording medium whose output is increased over a wide range of from long wavelengths to short wavelengths and whose output fluctuation with rotation period is decreased when rotating and reproducing in the form of a disk is provided comprising a non-magnetic support and a magnetic layer provided thereon containing a ferromagnetic substance, the magnetic layer having a multilayer structure consisting of a lower layer containing a ferromagnetic substance in an ellipsoidal shape with ##EQU1## and a saturation magnetization of at least 60 emu/g and an upper layer containing a ferromagnetic substance of plate-shaped hexagonal system having the axis of easy magnetization in the vertical direction to the plate surface.
    Type: Grant
    Filed: July 31, 1987
    Date of Patent: March 27, 1990
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Takamitsu Asai, Masaaki Fujiyama
  • Patent number: 4902584
    Abstract: An optical recording medium comprising a recording layer on a substrate and a protective layer formed adjacent to the upper or lower surface of the recording layer is more durable and corrosion resistant when the protective layer has a composition comprising silicon, a divalent metal such as Ba, Ca or Sr, oxygen, and nitrogen. An intermediate layer containing silicon, a metal or metalloid such as aluminum or lanthanum, oxygen and nitrogen is formed between the protective layer and the recording layer.
    Type: Grant
    Filed: December 23, 1987
    Date of Patent: February 20, 1990
    Assignee: TDK Corporation
    Inventors: Kenji Uchiyama, Hideki Ishizaki, Hajime Utsunomiya, Suguru Takayama
  • Patent number: 4897320
    Abstract: A magneto-optical recording medium comprises a recording layer formed of a magnetic material, and a protective layer composed of a combination of a dielectric material with a rare earth metal exhibiting a high oxygen absorptivity and formed on the recording layer by a simultaneous sputtering or a simultaneous deposition process, whereby free oxygen given rise to in the course of sputtering or deposition is absorbed on the protective layer side before being absorbed on the recording layer side.
    Type: Grant
    Filed: August 11, 1988
    Date of Patent: January 30, 1990
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Masaaki Nomura, Takashi Yamada, Ryoichi Yamamoto, Akira Nahara