Patents by Inventor Hazime Machida

Hazime Machida has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • 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: 4670323
    Abstract: The present invention provides a metal oxide magnetic substance represented by the general formula I:MeO.n[Ga.sub.X M.sub.Y.sup.I Fe.sub.2-X-(m/3)Y O.sub.3 ](wherein, Me is at least one member of Ba, Sr and Pb. M.sup.I is at least one member of Zn, Sc, In, Cr, Ir, Ru, Rh, Ti, Ta, Sn and Ge, 5.ltoreq.n.ltoreq.6, O<X.ltoreq.0.8, O<Y.ltoreq.0.8 and m is the ionic valency of M.sup.I) or represented by the general formula II:MeO.n[M.sub.T.sup.II Fe.sub.2-T O.sub.3 ](wherein, Me is at least one member of Ba, Sr and Pb, M.sup.II is at least one member of Ga and Al, 5.ltoreq.n.ltoreq.6 and O<T.ltoreq.1.0), a magnetic film consisting thereof, and a magneto optical recording medium and parpendicular magnetic recording medium having the magnetic film.
    Type: Grant
    Filed: November 23, 1984
    Date of Patent: June 2, 1987
    Assignee: Ricoh Company, Ltd.
    Inventors: Hitoshi Nakamura, Hazime Machida, Motoharu Tanaka, Atsuyuki Watada, Fumiya Omi, Nobuyuki Koinuma
  • Patent number: 4670322
    Abstract: The present invention provides a metal oxide magnetic substance represented by the general formula I:MeO.multidot.n[Al.sub.X M.sub.Y Fe.sub.2-x-(m/3)Y O.sub.3 ](wherein, Me is at least one member of Ba, Sr and Pb, M is at least one member of Zn, Sc, In, Cr, Ir, Ru, Rh, Ti, Ta, Sn and Ge, 5.ltoreq.n.ltoreq.6, 0<X.ltoreq.0.8, 0<Y.ltoreq.0.6, and m is the ionic valency of M), a magnetic film consisting thereof, and a magneto optical recording medium and a perpendicular magnetic recording medium having the magnetic film.
    Type: Grant
    Filed: November 29, 1984
    Date of Patent: June 2, 1987
    Assignee: Ricoh Company, Ltd.
    Inventors: Hitoshi Nakamura, Hazime Machida, Motoharu Tanaka, Atsuyuki Watada, Fumiya Omi, Nobuyuki Koinuma
  • Patent number: 4562105
    Abstract: Ferrimagnetic oxides of the following formula, ##EQU1## wherein Me represents at least one element selected from the group consisting of Ba, Sr and Pb, M.sub.I is at least one element selected from the group consisting of Ga and Al, M.sub.II is at least one element selected from the group consisting of Bi, Gd, Tb, Dy, Ho, La, Y, Co, Zn, Ti, Sc, In, Sn, Ca, Cr, Ni and Ge, 1.ltoreq.x.ltoreq.8, 0<y.ltoreq.6, 1.ltoreq.x+y.ltoreq.8, m is an ion valence of M.sub.I and n is an ion valence of M.sub.II, and a magneto-optical recording medium comprising a transparent substrate, a perpendicular magnetic-anisotropic magnetic film layer formed on the substrate, which magnetic film layer comprises one of the ferrimagnetic oxides of the above formula, and a reflection layer formed on the magnetic film layer, are disclosed.
    Type: Grant
    Filed: March 30, 1984
    Date of Patent: December 31, 1985
    Assignee: Ricoh Company, Ltd.
    Inventors: Hazime Machida, Motoharu Tanaka
  • Patent number: 4544602
    Abstract: A magneto-optical recording medium is disclosed, which comprises a transparent substrate, a vertical magnetic-anisotropic magnetic film layer formed thereon, which magnetic film layer comprises a ferrimagnetic oxide of the following formulaMeGa.sub.x Fe.sub.12-x O.sub.19wherein Me represents an element selected from the group consisting of Ba, Sr and Pb, and x is an integer of 3 to 8, and a reflection layer formed on the vertical magnetic-anisotropic film layer.
    Type: Grant
    Filed: March 16, 1984
    Date of Patent: October 1, 1985
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Kobayashi, Hazime Machida, Motoharu Tanaka
  • Patent number: 4413297
    Abstract: A magnetic recording and playback apparatus of perpendicular recording type comprises a main pole having a magnetic axis which is normal to a recording surface of a magnetic record medium, an auxiliary magnetic pole disposed in surrounding relationship with the main pole with a small clearance from the lateral side thereof, a coil disposed on part of the auxiliary pole, and a yoke having its one end connected to the auxiliary pole and having its other end of a relatively large area disposed in opposite relationship with the recording surface of the record medium. The free end of the main pole is disposed in contact with the surface of the record medium while the yoke is disposed at a given distance from the surface of the record medium. During a recording operation, a current is passed through the coil in accordance with information to be recorded.
    Type: Grant
    Filed: May 22, 1981
    Date of Patent: November 1, 1983
    Assignee: Ricoh Company, Ltd.
    Inventors: Motoharu Tanaka, Hazime Machida, Hiroshi Kobayashi
  • Patent number: 4282811
    Abstract: A method for desensitizing an offset printing plate which comprises applying an aqueous desensitizing composition consisting essentially of at least one complex to a non-image area of the offset printing plate having an oleophilic image formed thereon in an amount effective to desensitize said non-image area.
    Type: Grant
    Filed: August 10, 1979
    Date of Patent: August 11, 1981
    Assignee: Ricoh Co., Ltd.
    Inventors: Masayuki Kuzuwata, Hazime Machida, Hiroshi Tamura, Tadashi Saito
  • Patent number: 4208212
    Abstract: The present invention is intended to provide a cyanless treating liquid for use in offset printing which has an intense desensitizability, is capable of rapidly forming a firm hydrophilic film, is free from deterioration of the efficiency thereof when subjected to light or heat, and poses no problem of public nuisance.
    Type: Grant
    Filed: February 16, 1978
    Date of Patent: June 17, 1980
    Assignee: Ricoh Company, Ltd.
    Inventors: Masayuki Kuzuwata, Hazime Machida, Hiroshi Tamura, Tadashi Saito
  • Patent number: 4116698
    Abstract: The present invention provides a treating liquid for use in treating offset masters which treating liquid consists essentially of ferrocyanate, water-soluble phosphate and a specific polymer or copolymer. By the use of this treating liquid, the durability of offset masters in printing can be remarkably enhanced.
    Type: Grant
    Filed: September 23, 1977
    Date of Patent: September 26, 1978
    Assignee: Ricoh Co., Ltd.
    Inventors: Hazime Machida, Hiroshi Tamura, Kakuji Murakami
  • Patent number: 3933667
    Abstract: A wet developer for use in electrophotography which consists of a carrier liquid having electric resistance of 10.sup.9 .OMEGA. . cm or more and dielectric constant of less than 3 and containing colored particles with a particle size of about 0.1 .about. 10 .mu., said particles being substantially insoluble in said carrier liquid, possessed of properties of solid matter and showing a distinct polarity within said carrier liquid, coupled with adhesive suspended particles with a particle size of about 0.01 .about. 10 .mu. which show the same polarity as said colored particles.
    Type: Grant
    Filed: March 12, 1973
    Date of Patent: January 20, 1976
    Assignee: Kabushiki Kaisha Ricoh
    Inventors: Hazime Machida, Zenjiro Okuno