Patents by Inventor Nozomu Hachisuka

Nozomu Hachisuka 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: 20090154024
    Abstract: Provided is a thin-film magnetic head for reading data from a magnetic recording medium and/or writing data to a magnetic recording medium, in which the magnetic spacing can be controlled appropriately by stably adjusting the pressure working between the thin-film magnetic head and the magnetic recording medium according to the change of conditions such as the change over time. This thin-film magnetic head comprises at least one through hole reaching a surface opposed to the magnetic recording medium of the thin-film magnetic head, for adjusting a pressure working between the thin-film magnetic head and the magnetic recording medium. Preferably, the head further comprises at least one flow-amount control means for controlling the flow amount of gas that flows via the at least one through hole.
    Type: Application
    Filed: December 17, 2007
    Publication date: June 18, 2009
    Applicant: TDK CORPORATION
    Inventors: Nozomu HACHISUKA, Naoki OHTA
  • Publication number: 20090135520
    Abstract: A magnetic tape head has a base substrate, a magnetic head layer formed on the base substrate, and a closure piece formed on the magnetic head layer. The distance from a first plane comprising a point on the tape bearing surface of the base substrate to a third plane comprising a point on the tape bearing surface of the closure piece is equal to or greater than the distance from the first plane to a second plane comprising a point on the tape bearing surface of the magnetic head layer.
    Type: Application
    Filed: November 26, 2007
    Publication date: May 28, 2009
    Applicant: TDK CORPORATION
    Inventor: Nozomu Hachisuka
  • Publication number: 20090059439
    Abstract: Provided is a multichannel thin-film magnetic head having a plurality of read head elements neighboring with each other, each of which includes shield layers having a desired stable magnetic-domain structure. The head comprises at least one read head part comprising a plurality of read head elements aligned in the track width direction, wherein each of the plurality of read head elements comprises a lower shield layer and an upper shield layer, and the at least one read head part comprises: a lower shield part comprising a plurality of the lower shield layers aligned in the track width direction; and an upper shield part comprising a plurality of the upper shield layers aligned in the track width direction, and wherein dummy shield layers are provided respectively on both sides of at least the lower shield part.
    Type: Application
    Filed: September 4, 2007
    Publication date: March 5, 2009
    Applicant: TDK CORPORATION
    Inventors: Nozomu HACHISUKA, Yoshiyuki MIZOGUCHI, Hiroshi YAMAZAKI, Hideaki SATO
  • Patent number: 7440237
    Abstract: In a thin film magnetic head of the present invention, lead formation patterns of a first lead for connection between a lower shield layer and a first extraction electrode portion and a second lead for connection between an upper shield layer and a second extraction electrode portion are each formed so as not to have an overlapping portion with a heatsink layer but to bypass the heatsink layer when observing from the upper shield layer side toward the lower shield layer in a transparent state in plan view. Therefore, it is possible to increase an effect of heat radiation to the substrate side on the basis of the presence of the heatsink layer to thereby limit propagation of heat to a magnetoresistive effect layer as much as possible and further to achieve a drastic improvement in recording and reproducing characteristics at high recording frequencies, i.e. frequency characteristics (f characteristics) in a high frequency region.
    Type: Grant
    Filed: August 31, 2005
    Date of Patent: October 21, 2008
    Assignee: TDK Corporation
    Inventors: Noriaki Kasahara, Nozomu Hachisuka
  • Patent number: 7436633
    Abstract: A parasitic capacity C4 generated between a slider substrate and the first shield layer with the first insulating layer as a capacity layer is made substantially equal to a parasitic capacity C2 occurring between a lower magnetic layer and the second shield layer with the third insulating layer as a capacity layer. Preferably, a connection is made between the lower magnetic layer and the slider substrate by a resistance of preferably 100 (?) or lower. Thus, it is possible to provide a thin-film magnetic head that can hold back deterioration in a reproducing device and the occurrence of errors due to crosstalk between a recording device and the reproducing device and extraneous noises.
    Type: Grant
    Filed: August 17, 2005
    Date of Patent: October 14, 2008
    Assignee: TDK Corporation
    Inventors: Hiroshi Kiyono, Tetsuya Kuwashima, Takeo Kagami, Noriaki Kasahara, Naoki Ohta, Nozomu Hachisuka
  • Publication number: 20080218900
    Abstract: A multi-channel thin-film magnetic head has magnetic read head elements, magnetic write head elements, servo magnetic head elements, a plurality of pairs of external connection pads for reading connected with magnetic read head elements, a plurality of pairs of external connection pads for writing connected with magnetic write head elements, a plurality of pairs of external connection pads for servo connected with servo magnetic head elements, and a plurality of connection pads for body grounding or other functions. The connection pads for reading, writing, servo and body grounding or other functions are arranged in lines on a surface of the multi-channel thin-film magnetic head, and lead conductors which are electrically connected with connection pads for reading, writing, servo and body grounding or other functions are different each other in terms of widths, shapes, connection points or existence of a connector among at least two types of connection pads.
    Type: Application
    Filed: March 9, 2007
    Publication date: September 11, 2008
    Applicant: TDK CORPORATION
    Inventors: Nozomu Hachisuka, Tetsuya Hiraki
  • Patent number: 7417442
    Abstract: A method for testing a TMR element includes a step of measuring a plurality of resistances of the TMR element by feeding a plurality of sense currents with different current values each other through the TMR element, a step of calculating a ratio of change in resistance from the measured plurality of resistances of the TMR element, and a step of evaluating the TMR element using the calculated ratio of change in resistance.
    Type: Grant
    Filed: May 17, 2005
    Date of Patent: August 26, 2008
    Assignees: TDK Corporation, SAE Magnetics (H.K.) Ltd.
    Inventors: Nozomu Hachisuka, Kenji Inage, Norio Takahashi, Tatsushi Shimizu, Pak Kin Wong
  • Patent number: 7372282
    Abstract: A method for testing a TMR element includes a step of measuring a plurality of resistances of the TMR element by applying a plurality of voltages with different voltage values each other to the TMR element, respectively, a step of calculating a ratio of change in resistance from the measured plurality of resistances of the TMR element, and a step of evaluating the TMR element using the calculated ratio of change in resistance.
    Type: Grant
    Filed: March 13, 2006
    Date of Patent: May 13, 2008
    Assignee: TDK Corporation
    Inventors: Nozomu Hachisuka, Hiroshi Kiyono, Takeo Kagami, Kenji Inage, Norio Takahashi
  • Patent number: 7287316
    Abstract: A lapping monitor element that is juxtaposed with a magnetic transducer element having a magnetoresistance effect film to determine the lapping position upon lapping the element height of the magnetic transducer element to a predetermined dimension. The lapping monitor element includes a resistance film to be resistance measured. The resistance film is a metal film of nonmagnetic transition metal or of alloy composed mainly of nonmagnetic transition metal, or a multilayered film where two or more such metal films are laid one upon another. The lapping monitor makes it possible to extremely stabilize the ELG sensor resistance measured values upon lapping as well as to provide a high accuracy MR height control.
    Type: Grant
    Filed: July 15, 2002
    Date of Patent: October 30, 2007
    Assignee: TDK Corporation
    Inventors: Noriaki Kasahara, Nozomu Hachisuka, Yasutoshi Fujita
  • Patent number: 7274539
    Abstract: A composite type thin-film magnetic head is provided, which comprises: a MR read head element having an upper shield layer, a lower shield layer, an MR layer in which a sense current flows in a direction perpendicular to a surface of the layer through the upper shield layer and the lower shield layer; an inductive write head element formed on the MR read head element, having an upper magnetic pole layer, a recording gap layer, a lower magnetic pole layer where end portion is opposed to an end portion of the upper magnetic pole layer through the recording gap layer, and a write coil; and a capacitance C12 between the write coil and the upper shield layer, set to 0.1 pF or less.
    Type: Grant
    Filed: March 15, 2005
    Date of Patent: September 25, 2007
    Assignee: TDK Corporation
    Inventors: Hiroshi Kiyono, Nozomu Hachisuka, Shunji Saruki, Noriaki Kasahara
  • Patent number: 7236392
    Abstract: Testing a TMR element includes a step of measuring initially a resistance value of the TMR element to provide the measured resistance value as a first resistance value, a step of measuring a resistance value of the TMR element after continuously feeding a current through the TMR element from a anti-substrate side to a substrate side for a predetermined period of time, to provide the measured resistance value as a second resistance value, and a step of evaluating the TMR element by comparing the first resistance value and the second resistance value with each other.
    Type: Grant
    Filed: April 8, 2005
    Date of Patent: June 26, 2007
    Assignee: TDK Corporation
    Inventors: Shunji Saruki, Kenji Inage, Nozomu Hachisuka, Hiroshi Kiyono
  • Patent number: 7227772
    Abstract: Testing a TMR element includes a step of measuring initially a resistance value of the TMR element to provide the measured resistance value as a first resistance value, a step of measuring a resistance value of the TMR element after continuously feeding a current through the TMR element for a predetermined period of time, to provide the measured resistance value as a second resistance value, and a step of evaluating the TMR element depending upon a degree of change in resistance of the TMR element. The degree of change in resistance is determined based upon the first resistance value and the second resistance value.
    Type: Grant
    Filed: March 3, 2005
    Date of Patent: June 5, 2007
    Assignee: TDK Corporation
    Inventors: Shunji Saruki, Kenji Inage, Nozomu Hachisuka, Hiroshi Kiyono
  • Publication number: 20070103815
    Abstract: A magnetic head assembly includes a magnetic head slider with an element-formed surface on which at least one MR read head element is formed, an ABS to be opposed in operation to a magnetic recording medium and a fixing surface that is the other side of the ABS, and a support for supporting the magnetic head slider. The fixing surface of the magnetic head slider is fixed to the support by at least cure-shrinkage resin material layer providing a contractive force when cured. The cure-shrinkage resin material layer has at least one strip-shaped pattern running along a track width direction.
    Type: Application
    Filed: August 31, 2006
    Publication date: May 10, 2007
    Applicant: TDK CORPORATION
    Inventors: Naoki OHTA, Nozomu Hachisuka
  • Publication number: 20060216837
    Abstract: A method for testing a TMR element includes a step of measuring a plurality of resistances of the TMR element by applying a plurality of voltages with different voltage values each other to the TMR element, respectively, a step of calculating a ratio of change in resistance from the measured plurality of resistances of the TMR element, and a step of evaluating the TMR element using the calculated ratio of change in resistance.
    Type: Application
    Filed: March 13, 2006
    Publication date: September 28, 2006
    Applicant: TDK CORPORATION
    Inventors: Nozomu HACHISUKA, Hiroshi Kiyono, Takeo Kagami, Kenji Inage, Norio Takahashi
  • Patent number: 7102859
    Abstract: A thin-film magnetic head includes a TMR element and a resistor element connected in parallel with the TMR element. A resistance value RTMR of the TMR element itself is RTMR?240 ?, a product RA of the resistance value of the TMR element itself and a cross-sectional area of the TMR element is RA?3 ?ยท?m2, and a resistance value RPARA of the resistor element is RPARA?480?.
    Type: Grant
    Filed: January 28, 2004
    Date of Patent: September 5, 2006
    Assignee: TDK Corporation
    Inventors: Kenji Inage, Shunji Saruki, Nozomu Hachisuka
  • Publication number: 20060098349
    Abstract: In a thin film magnetic head of the present invention, lead formation patterns of a first lead for connection between a lower shield layer and a first extraction electrode portion and a second lead for connection between an upper shield layer and a second extraction electrode portion are each formed so as not to have an overlapping portion with a heatsink layer but to bypass the heatsink layer when observing from the upper shield layer side toward the lower shield layer in a transparent state in plan view. Therefore, it is possible to increase an effect of heat radiation to the substrate side on the basis of the presence of the heatsink layer to thereby limit propagation of heat to a magnetoresistive effect layer as much as possible and further to achieve a drastic improvement in recording and reproducing characteristics at high recording frequencies, i.e. frequency characteristics (f characteristics) in a high frequency region.
    Type: Application
    Filed: August 31, 2005
    Publication date: May 11, 2006
    Applicant: TDK Corporation
    Inventors: Noriaki Kasahara, Nozomu Hachisuka
  • Publication number: 20060082929
    Abstract: A parasitic capacity C4 generated between a slider substrate and the first shield layer with the first insulating layer as a capacity layer is made substantially equal to a parasitic capacity C2 occurring between a lower magnetic layer and the second shield layer with the third insulating layer as a capacity layer. Preferably, a connection is made between the lower magnetic layer and the slider substrate by a resistance of preferably 100 (?) or lower. Thus, it is possible to provide a thin-film magnetic head that can hold back deterioration in a reproducing device and the occurrence of errors due to crosstalk between a recording device and the reproducing device and extraneous noises.
    Type: Application
    Filed: August 17, 2005
    Publication date: April 20, 2006
    Applicant: TDK Corporation
    Inventors: Hiroshi Kiyono, Tetsuya Kuwashima, Takeo Kagami, Noriaki Kasahara, Naoki Ohta, Nozomu Hachisuka
  • Publication number: 20060023333
    Abstract: A method for testing a TMR element includes a step of measuring a plurality of resistances of the TMR element by feeding a plurality of sense currents with different current values each other through the TMR element, a step of calculating a ratio of change in resistance from the measured plurality of resistances of the TMR element, and a step of evaluating the TMR element using the calculated ratio of change in resistance.
    Type: Application
    Filed: May 17, 2005
    Publication date: February 2, 2006
    Applicants: TDK Corporation, SAE Magnetics (H.K.) Ltd.
    Inventors: Nozomu Hachisuka, Kenji Inage, Norio Takahashi, Tatsushi Shimizu, Pak Wong
  • Publication number: 20050237789
    Abstract: A method for testing a TMR element includes a step of measuring initially a resistance value of the TMR element to provide the measured resistance value as a first resistance value, a step of measuring a resistance value of the TMR element after continuously feeding a current through the TMR element from a anti-substrate side to a substrate side for a predetermined period of time, to provide the measured resistance value as a second resistance value, and a step of evaluating the TMR element by comparing the first resistance value and the second resistance value with each other.
    Type: Application
    Filed: April 8, 2005
    Publication date: October 27, 2005
    Applicant: TDK Corporation
    Inventors: Shunji Saruki, Kenji Inage, Nozomu Hachisuka, Hiroshi Kiyono
  • Publication number: 20050219765
    Abstract: A composite type thin-film magnetic head is provided, which comprises: a MR read head element having an upper shield layer, a lower shield layer, an MR layer in which a sense current flows in a direction perpendicular to a surface of the layer through the upper shield layer and the lower shield layer; an inductive write head element formed on the MR read head element, having an upper magnetic pole layer, a recording gap layer, a lower magnetic pole layer where end portion is opposed to an end portion of the upper magnetic pole layer through the recording gap layer, and a write coil; and a capacitance C12 between the write coil and the upper shield layer, set to 0.1 pF or less.
    Type: Application
    Filed: March 15, 2005
    Publication date: October 6, 2005
    Applicant: TDK Corporation
    Inventors: Hiroshi Kiyono, Nozomu Hachisuka, Shunji Saruki, Noriaki Kasahara