Patents by Inventor Kouji Shimazawa

Kouji Shimazawa 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: 10152991
    Abstract: A method for manufacturing a TAMR (thermal assisted magnetic recording) write head. The write head has a metal blocker formed against a distal end of a waveguide. The waveguide focuses optical radiation on an adjacent plasmon generator where it excites plasmon modes that heat the recording medium. Although the plasmon generator typically heats the recording medium using the plasmon near field to supply the required Joule heating, an unblocked waveguide would also send optical radiation to the medium and surrounding structures producing unwanted heating and device unreliability. The role of the blocker is to block the unwanted optical radiation and, thereby, to limit the heating to that supplied by the plasmon near field.
    Type: Grant
    Filed: December 11, 2017
    Date of Patent: December 11, 2018
    Assignee: Headway Technologies, Inc.
    Inventors: Tsutomu Chou, Kouji Shimazawa, Tobias Maletzky, Weihao Xu, Shinji Hara, Yoshihiro Tsuchiya, Yiming Wang, Cherng-Chyi Han, Xuhui Jin
  • Publication number: 20180182419
    Abstract: A TAMR (thermal assisted magnetic recording) write head and a method of its fabrication. The write head has a metal blocker formed against a distal end of a waveguide. The waveguide focuses optical radiation on an adjacent plasmon generator where it excites plasmon modes that heat the recording medium. Although the plasmon generator typically heats the recording medium using the plasmon near field to supply the required Joule heating, an unblocked waveguide would also send optical radiation to the medium and surrounding structures producing unwanted heating and device unreliability. The role of the blocker is to block the unwanted optical radiation and, thereby, to limit the heating to that supplied by the plasmon near field.
    Type: Application
    Filed: December 11, 2017
    Publication date: June 28, 2018
    Inventors: Tsutomu Chou, Kouji Shimazawa, Tobias Maletzky, Weihao Xu, Shinji Hara, Yoshihiro Tsuchiya, Yiming Wang, Cherng-Chyi Han, Xuhui Jin
  • Patent number: 9852752
    Abstract: A TAMR (thermal assisted magnetic recording) write head has a metal blocker formed against a distal end of a waveguide. The waveguide focuses optical radiation on an adjacent plasmon generator where it excites plasmon modes that heat the recording medium. Although the plasmon generator typically heats the recording medium using the plasmon near field to supply the required Joule heating, an unblocked waveguide would also send optical radiation to the medium and surrounding structures producing unwanted heating and device unreliability. The role of the blocker is to block the unwanted optical radiation and, thereby, to limit the heating to that supplied by the plasmon near field.
    Type: Grant
    Filed: August 12, 2016
    Date of Patent: December 26, 2017
    Assignee: Headway Technologies, Inc.
    Inventors: Tsutomu Chou, Kouji Shimazawa, Tobias Maletzky, Weihao Xu, Shinji Hara, Yoshihiro Tsuchiya, Yiming Wang, Cherng-Chyi Han, Xuhui Jin
  • Patent number: 8593915
    Abstract: A slider mounted TAMR (Thermal Assisted Magnetic Recording), DFH (Dynamic Flying Height) type read/write head using optical-laser generated surface plasmons in a small antenna to locally heat a magnetic medium, uses the same optical laser at low power to pre-heat the antenna. Maintaining the antenna at this pre-heated temperature, approximately 50% of its highest temperature during write operations, allows the DFH mechanism sufficient time to compensate for the thermal protrusion of the antenna at that lower temperature, so that thermal protrusion transients are significantly reduced when a writing operation occurs and full laser power is applied. The time constant for antenna protrusion is less than the time constant for DFH fly height compensation, so, without pre-heating, the thermal protrusion of the antenna due to absorption of optical radiation cannot be compensated by the DFH effect.
    Type: Grant
    Filed: August 1, 2011
    Date of Patent: November 26, 2013
    Assignee: Headway Technologies, Inc.
    Inventors: Erhard Schreck, Kowang Liu, Kouji Shimazawa, Po-Kang Wang
  • Publication number: 20110292773
    Abstract: A slider mounted TAMR (Thermal Assisted Magnetic Recording), DFH (Dynamic Flying Height) type read/write head using optical-laser generated surface plasmons in a small antenna to locally heat a magnetic medium, uses the same optical laser at low power to pre-heat the antenna. Maintaining the antenna at this pre-heated temperature, approximately 50% of its highest temperature during write operations, allows the DFH mechanism sufficient time to compensate for the thermal protrusion of the antenna at that lower temperature, so that thermal protrusion transients are significantly reduced when a writing operation occurs and full laser power is applied. The time constant for antenna protrusion is less than the time constant for DFH fly height compensation, so, without pre-heating, the thermal protrusion of the antenna due to absorption of optical radiation cannot be compensated by the DFH effect.
    Type: Application
    Filed: August 1, 2011
    Publication date: December 1, 2011
    Inventors: Erhard Schreck, Kowang Liu, Kouji Shimazawa, Po-Kang Wang
  • Patent number: 7995425
    Abstract: A slider mounted TAMR (Thermal Assisted Magnetic Recording), DFH (Dynamic Flying Height) type read/write head using optical-laser generated surface plasmons in a small antenna to locally heat a magnetic medium, uses the same optical laser at low power to pre-heat the antenna. Maintaining the antenna at this pre-heated temperature, approximately 50% of its highest temperature during write operations, allows the DFH mechanism sufficient time to compensate for the thermal protrusion of the antenna at that lower temperature, so that thermal protrusion transients are significantly reduced when a writing operation occurs and full laser power is applied. The time constant for antenna protrusion is less than the time constant for DFH fly height compensation, so, without pre-heating, the thermal protrusion of the antenna due to absorption of optical radiation cannot be compensated by the DFH effect.
    Type: Grant
    Filed: March 11, 2009
    Date of Patent: August 9, 2011
    Assignee: Headway Technologies, Inc.
    Inventors: Erhard Schreck, Kowang Liu, Kouji Shimazawa, Po-Kang Wang
  • Publication number: 20100232050
    Abstract: A slider mounted TAMR (Thermal Assisted Magnetic Recording), DFH (Dynamic Flying Height) type read/write head using optical-laser generated surface plasmons in a small antenna to locally heat a magnetic medium, uses the same optical laser at low power to pre-heat the antenna. Maintaining the antenna at this pre-heated temperature, approximately 50% of its highest temperature during write operations, allows the DFH mechanism sufficient time to compensate for the thermal protrusion of the antenna at that lower temperature, so that thermal protrusion transients are significantly reduced when a writing operation occurs and full laser power is applied. The time constant for antenna protrusion is less than the time constant for DFH fly height compensation, so, without pre-heating, the thermal protrusion of the antenna due to absorption of optical radiation cannot be compensated by the DFH effect.
    Type: Application
    Filed: March 11, 2009
    Publication date: September 16, 2010
    Inventors: Erhard Schreck, Kowang Liu, Kouji Shimazawa, Po-Kang Wang
  • Patent number: 6123781
    Abstract: A method of controlling magnetic characteristics of a spin valve effect MR element and a method of controlling magnetic characteristics of a magnetic head with the MR element include a step of supplying direct current with a gradually increasing value to the MR element so as to generate magnetic field in a desired direction and to generate joule heat, the generated magnetic field and the generated joule heat being applied to the MR element, and a step of controlling a magnetization direction caused by exchange coupling in the MR element based upon the applied magnetic field and the applied joule heat.
    Type: Grant
    Filed: February 23, 1998
    Date of Patent: September 26, 2000
    Assignee: TDK Corporation
    Inventor: Kouji Shimazawa
  • Patent number: 6081114
    Abstract: A method of testing a magnetic head with a spin-valve MR element having a pinned direction, includes a step of reproducing magnetic information recorded on a magnetic medium by the spin-valve MR element of the magnetic head to be tested to generate a reproduced signal, the information being recorded on the magnetic medium by using a rectangular wave current with a predetermined pattern, and a step of judging whether the pinned direction of the spin-valve MR element is correct in accordance with a relationship between wave shape of the reproduced signal and the predetermined pattern.
    Type: Grant
    Filed: February 17, 1998
    Date of Patent: June 27, 2000
    Assignee: TDK Corporation
    Inventors: Kouji Shimazawa, Masanori Sakai