Patents by Inventor Jun Koujima

Jun Koujima 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).

  • Publication number: 20120091210
    Abstract: The present invention relates to a composite RF tag for transmitting and receiving information using an electromagnetic induction method, comprising a magnetic antenna mounted with an IC, and a resin layer formed around the magnetic antenna, wherein the magnetic antenna comprises a central core formed of a magnetic material and a coil-shaped electrode material disposed around the core. The RF tag according to the present invention comprises the magnetic antenna surrounded by the resin, and therefore can provide a composite magnetic RF tag which can minimize adverse influence by surrounding water or metals in view of maintenance of tools or parts to which the composite RF tag is mounted, and is free from occurrence of any failure or cracking.
    Type: Application
    Filed: March 25, 2010
    Publication date: April 19, 2012
    Inventors: Jun Koujima, Takanori Doi, Tetsuya Kimura, Yoshiro Sato
  • Publication number: 20110124299
    Abstract: The present invention relates to a magnetic antenna for information communication using a magnetic field component which is capable of satisfying both reduction in size and improvement in communication sensitivity. The magnetic antenna of the present invention is used for transmitting and receiving information using an electromagnetic induction method, and comprises a central core formed of a magnetic material and a non-magnetic material, a coil-shaped electrode material wound around the core, and an insulating layer formed on at least one outside surface of the core on which the coil-shaped electrode material is provided, in which the magnetic material is separated into two or more parts through the non-magnetic material when viewed in a section of the core which is perpendicular to a magnetic flux passing therethrough.
    Type: Application
    Filed: April 22, 2009
    Publication date: May 26, 2011
    Inventors: Jun Koujima, Tetsuya Kimura, Takanori Doi, Yoshiro Sato
  • Publication number: 20110101113
    Abstract: The present invention relates to a composite magnetic antenna for information communication utilizing a magnetic field component as well as a composite RF tag using the composite magnetic antenna, which can be embedded in metals while maintaining a sufficient communication sensitivity unlike conventional RF tags which were unusable in the metal embedding applications.
    Type: Application
    Filed: May 12, 2009
    Publication date: May 5, 2011
    Inventors: Jun Koujima, Tetsuya Kimura, Takanori Doi, Yoshiro Sato
  • Publication number: 20070111038
    Abstract: A magnetic recording medium comprises a polymer film substrate having an elongated shape or a polymer flexible substrate; an underlayer having a thickness of less than 10 nm, which is formed on the substrate; and a magnetic recording layer comprising a spinel iron oxide thin film containing maghemite as a main component, which is formed on the underlayer and has a coercive force of not less than 159 kA/m (2000 Oe). The present invention provides the magnetic recording medium comprising a spinel iron oxide thin film containing maghemite as a main component, which exhibits an excellent recording resolution performance while maintaining a high coercive force and a high coercive force squareness.
    Type: Application
    Filed: November 15, 2005
    Publication date: May 17, 2007
    Applicant: Toda Kogyo Corporation
    Inventors: Jun Koujima, Teruaki Santoki, Takanori Doi
  • Patent number: 6916530
    Abstract: A perpendicular magnetic recording medium, comprises a substrate; a soft-magnetic layer formed on the substrate; an NaCl-type oxide layer for orientation control formed on the soft-magnetic layer, having a thickness of from more than 0 to less than 10 nm; and a magnetic recording layer formed on the NaCl-type oxide layer for orientation control, comprising a maghemite thin film. Such a perpendicular magnetic recording medium is capable of showing excellent magnetic properties, a high recording resolution and improved surface properties.
    Type: Grant
    Filed: September 26, 2002
    Date of Patent: July 12, 2005
    Assignee: Toda Kogyo Corporation
    Inventors: Jun Koujima, Teruaki Santoki, Masaaki Maekawa, Takanori Doi
  • Patent number: 6821618
    Abstract: A magnetic recording medium exhibiting a high coercive force and excellent squareness having a substrate, an underlayer formed on the substrate, and a spinel-type iron oxide thin film with maghemite as a main component formed on the underlayer. The spinel-type iron oxide thin film has a thickness (t) of 5 to 50 nm, is constituted by grains having an average grain size (D) of 5 to 30 nm, standard deviation of sizes of grain of not more than 4 nm and a ratio (D/t) of the average grain size (D) to the thickness (t) of less than 1.0, exhibits a coercive force of not less than 159 kA/m (2,000 Oe) and a coercive squareness ratio S* of not less than 0.5:1 in a longitudinal recording medium or a squareness ratio not less than 0.75:1 in a perpendicular recording medium.
    Type: Grant
    Filed: July 1, 2002
    Date of Patent: November 23, 2004
    Assignee: Toda Kogyo Corporation
    Inventors: Jun Koujima, Teruaki Santoki, Kenichi Nakata, Takanori Doi, Masaaki Maekawa, Kousaku Tamari
  • Patent number: 6753077
    Abstract: A magnetic recording medium including a substrate and formed on the substrate a maghemite thin film having a surface roughness represented by a center line mean roughness Ra of 0.1 to 1.0 nm, and a coercive force squareness S* value of not less than 0.50. This magnetic recording medium exhibits excellent magnetic properties, especially, coercive force squareness S* value and a more enhanced surface smoothness.
    Type: Grant
    Filed: December 22, 2000
    Date of Patent: June 22, 2004
    Assignee: Toda Kogyo Corporation
    Inventors: Kenichi Nakata, Kousaku Tamari, Jun Koujima, Teruaki Santoki
  • Publication number: 20030143434
    Abstract: A perpendicular magnetic recording medium, comprises a substrate; a soft-magnetic layer formed on the substrate; an NaCl-type oxide layer for orientation control formed on the soft-magnetic layer, having a thickness of from more than 0 to less than 10 nm; and a magnetic recording layer formed on the NaCl-type oxide layer for orientation control, comprising a maghemite thin film. Such a perpendicular magnetic recording medium is capable of showing excellent magnetic properties, a high recording resolution and improved surface properties.
    Type: Application
    Filed: September 26, 2002
    Publication date: July 31, 2003
    Inventors: Jun Koujima, Teruaki Santoki, Masaaki Maekawa, Takanori Doi
  • Publication number: 20030008176
    Abstract: A magnetic recording medium, comprising: a substrate; an underlayer formed on the substrate; and a spinel-type iron oxide thin film comprising maghemite as a main component formed on the underlayer,
    Type: Application
    Filed: July 1, 2002
    Publication date: January 9, 2003
    Inventors: Jun Koujima, Teruaki Santoki, Kenichi Nakata, Takanori Doi, Masaaki Maekawa, Kousaku Tamari
  • Publication number: 20020094458
    Abstract: A magnetic recording medium, comprising: a substrate; and a maghemite thin film formed on the substrate, having a surface roughness represented by a center line mean roughness Ra of 0.1 to 1.0 nm, and a coercive force squareness S* value of not less than 0.50.
    Type: Application
    Filed: December 22, 2000
    Publication date: July 18, 2002
    Inventors: Kenichi Nakata, Kousaku Tamari, Jun Koujima, Teruaki Santoki