Patents by Inventor Tsutomu Choh

Tsutomu Choh 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).

  • Soft magnetic alloy, method for making, magnetic core, magnetic shield and compressed powder core using the same
    Patent number: 5252148
    Abstract: A soft magnetic alloy having a composition of general formula:(Fe.sub.1-a Ni.sub.a).sub.100-x-y-z-p-q Cu.sub.x Si.sub.y B.sub.z Cr.sub.p M.sup.1.sub.q (I)wherein M.sup.1 is V or Mn or a mixture of V and Mn, 0.ltoreq.a.ltoreq.0.5, 0.1.ltoreq.x.ltoreq.5, 6.ltoreq.y.ltoreq.20, 6.ltoreq.z.ltoreq.20, 15.ltoreq.y+z.ltoreq.30, 0.5.ltoreq.p.ltoreq.10, and 0.5.ltoreq.q.ltoreq.10 and possessing a fine crystalline phase is suitable as a core, especially a wound core and a compressed powder core.
    Type: Grant
    Filed: August 10, 1992
    Date of Patent: October 12, 1993
    Assignee: TDK Corporation
    Inventors: Masao Shigeta, Asako Kajita, Ippo Hirai, Tsutomu Choh
  • Magnetic shield-forming magnetically soft powder, composition thereof, and process of making
    Patent number: 4923533
    Abstract: A powder comprising flakes of magnetically soft amorphous alloy having an average thickness of 0.01-1 .mu.m and an aspect ratio of 10-10,000 is blended with a binder to form a coating composition from which a magnetic shield is fabricated. The alloy is basically an Fe-B-Si ternary alloy in which iron may be partially replaced by another metal.
    Type: Grant
    Filed: July 29, 1988
    Date of Patent: May 8, 1990
    Assignees: TDK Corporation, Tokyo Magnetic Printing Company, Ltd.
    Inventors: Masao Shigeta, Tsutomu Choh, Hiroyoshi Shimizu, Ippo Hirai, Shohei Mimura, Atsushi Makimura, Hiroshi Hosaka