Patents by Inventor Tsutomu Kenpo

Tsutomu Kenpo 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: 5698313
    Abstract: Disclosed is a magnetic recording medium comprising a nonmagnetic base support and a magnetic layer containing ferromagnetic metallic powder dispersed in a binder, wherein the strain dependability of said magnetic recording medium is characterized in that: a ratio G'.sub.2 /G'.sub.1 is not less than 0.01, wherein G'.sub.1 is a storage modulus provided that the strain is 10.sup.-4, and G'.sub.2 is a storage modulus provided that the strain is 10.sup.-2.
    Type: Grant
    Filed: December 23, 1993
    Date of Patent: December 16, 1997
    Assignee: Konica Corporation
    Inventors: Naoto Yamamoto, Tsutomu Kenpo
  • Patent number: 5208091
    Abstract: A magnetic recording medium comprising at least two magnetic layers provided on a non-magnetic support, and a backing layer on the support on the side opposite to said magnetic layers, wherein said backing layer has, on the surface thereof, the protrusions each having a height of the peaks thereof within the range of 0.05 .mu.m to 0.6 .mu.m wherein the amount of the protrusions is within the range of 10,000 to 100,000 cm.sub.2 and an interval of the peaks of not less than 10 .mu.m.
    Type: Grant
    Filed: July 25, 1990
    Date of Patent: May 4, 1993
    Assignee: Konica Corporation
    Inventors: Takafumi Yanagita, Tsutomu Kenpo
  • Patent number: 5145745
    Abstract: A magnetic recording medium having superior electromagnetic conversion characteristics and travel durability in a well balanced state. The recording medium comprises a non-magnetic support and a plurality of magnetic layers each comprising a ferromagnetic powder and a binder and each of the magnetic layers shows a peak of its loss modulus at a temperature not less than 50.degree. C. and the half-width of the loss modulus-temperature curve showing the peak of loss modulus is not larger than 20.degree. C.; and the temperature of the peak of loss modulas of the outermost magnetic layer provided at the outermost portion among the magnetic layers is higher than that of a magnetic layer other than the outermost magnetic layer.
    Type: Grant
    Filed: September 26, 1990
    Date of Patent: September 8, 1992
    Assignee: Konica Corporation
    Inventors: Atsuko Matsuda, Tsutomu Kenpo
  • Patent number: 5084336
    Abstract: The method of improving a magnetic recording medium having a support, provided thereon a magnetic layer, and provided on an another side of the support a back coating layer, is disclosed. The improvement comprises the back coating layer containing a binder and a non-magnetic powder comprising essentially of a combination of carbon black and a non-magnetic particle selected from the group consisting of zinc oxide, titanium oxide, barium sulfate, ferric oxide and calcium carbonate.
    Type: Grant
    Filed: December 22, 1988
    Date of Patent: January 28, 1992
    Assignee: Konica Corporation
    Inventors: Tsutomu Kenpo, Takafumi Yanagita
  • Patent number: 5043212
    Abstract: A magnetic recording medium having plural magnetic layers is disclosed. The magnetic recording medium comprises a first magnetic layer containing magnetic powder having a coercive force of less than 800 Oe and a BET value of less than 45 m.sup.2 /g, a second magnetic layer containing magnetic powder having a coercive force of not less than 800 Oe and a BET value of less than 45 m.sup.2 /g and a third magnetic layer containing magnetic powder having a coercive force of not less than 800 Oe and a BET value of not less than 45 m.sup.2 /g, in this order.
    Type: Grant
    Filed: August 24, 1990
    Date of Patent: August 27, 1991
    Assignee: Konica Corporation
    Inventors: Yasuo Ando, Tsutomu Kenpo