Patents by Inventor Norikazu Ota

Norikazu Ota 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: 20050270694
    Abstract: A thin-film magnetic head according to the present invention comprises: a substrate; at least one magnetic head element formed on the substrate; an overcoat multilayer composed of a plurality of overcoat layers, formed on the substrate so as to cover the at least one magnetic head element; and at least one heating element to be heated at least during operation of the at least one magnetic head element, the at least one heating element provided in the overcoat multilayer, and a coefficient of thermal expansion of an overcoat layer located farthest from the substrate in the overcoat multilayer being smaller than a coefficient of thermal expansion of an overcoat layer located closest to the substrate in the overcoat multilayer.
    Type: Application
    Filed: May 13, 2005
    Publication date: December 8, 2005
    Applicant: TDK Corporation
    Inventors: Tsuyoshi Umehara, Norikazu Ota, Katsumichi Tagami, Hiroki Matsukuma, Nobuya Oyama, Soji Koide, Yoshiyuki Mizoguchi, Kazuhide Yamada
  • Publication number: 20050254171
    Abstract: A thin-film magnetic head includes at least one inductive write head element and at least one read magnetic head element, capable of controlling a spacing between a magnetic recording medium and the at least one magnetic read head element by heating. A gain SG (nm/° C.) of the spacing is greater than a spacing gain threshold SGTHLD (nm/° C.) defined by the following expression: SGLIMT=A*dPTP+B A=1.4642E?02*exp(?6.6769E?05*LRDMF) B=4.9602E?01*exp(?2.0423E?03*LRDMF) where dPTP represents an amount of change in protrusion (nm) of a top end of the at least one inductive write head element and/or the at least one read magnetic head element by heating, and LRDMF represents a line recording density (kFCI) at a frequency half of the maximum recording frequency.
    Type: Application
    Filed: April 26, 2005
    Publication date: November 17, 2005
    Applicant: TDK Corporation
    Inventors: Norikazu Ota, Kenji Inage, Taro Oike
  • Patent number: 6945847
    Abstract: A thin-film magnetic head is formed on a support and is provided with a reproducing head part, a recording head part, and a heater for generating heat upon energization. A medium-opposing surface S of the magnetic head is polished while energizing the heater or recording head part.
    Type: Grant
    Filed: March 3, 2004
    Date of Patent: September 20, 2005
    Assignee: TDK Corporation
    Inventors: Norikazu Ota, Takehiro Kamigama, Nobuya Oyama, Soji Koide, Tetsuro Sasaki
  • Patent number: 6920020
    Abstract: In the thin-film magnetic head of the present invention, the distance to a heat-generating layer is shorter from the end part on the side facing, a recording medium in a magnetoresistive device than from the end part on the side facing the recording medium in an electromagnetic transducer. Therefore, even when the thin-film magnetic head tilts so that its electromagnetic transducer side approaches the recording medium when floating up from the recording medium, the amount of thermal expansion caused by the heat from the heat-generating layer is greater in the magnetoresistive device than in the electromagnetic transducer. This reduces the gap between the magnetoresistive device and the recording medium, whereby a high reproducing output can be obtained.
    Type: Grant
    Filed: April 24, 2003
    Date of Patent: July 19, 2005
    Assignee: TDK Corporation
    Inventors: Noboru Yamanaka, Norikazu Ota
  • Publication number: 20050099735
    Abstract: A precise positioning actuator to be fixed to a head slider provided with at least one head element, for precisely positioning the at least one head element includes a base, and a pair of movable arms extending from the base and having slider fixing portions to be fixed to side surfaces of the head slider at top end sections thereof. Each of the pair of movable arms includes an arm member and an actuator layer formed on a side surface of the arm member, for displacing the arm member in response to a drive signal applied thereto. The actuator layer is terminated on the side surface of the arm member at a frontward position form the slider fixing portion.
    Type: Application
    Filed: November 24, 2004
    Publication date: May 12, 2005
    Inventors: Norikazu Ota, Takeshi Wada, Takashi Honda
  • Publication number: 20050047016
    Abstract: The head slider in accordance with the present invention comprises a thin-film magnetic head including a magnetoresistive device and an electromagnetic transducer, and a heater adapted to generate heat upon energization. At least one of a reproducing bump, a recording bump, and a heater bump includes a bypass layer extending in a direction intersecting a bump extending direction, a first bump portion positioned closer to a pad-forming surface than is the bypass layer, and a second bump portion positioned on the side of the bypass layer opposite from the first bump portion. The first and second bump portions are displaced from each other in the bypass layer extending direction.
    Type: Application
    Filed: July 9, 2004
    Publication date: March 3, 2005
    Applicant: TDK CORPORATION
    Inventors: Soji Koide, Norikazu Ota, Nobuya Oyama, Tetsuro Sasaki
  • Publication number: 20050047015
    Abstract: Provided is a thin film magnetic head capable of reducing the amount of protrusion of a write shield layer, thereby preventing a collision with a recording medium, and thereby ensuring a recording operation with stability. A heat sink layer is disposed on the leading side of a thin film coil in order to dissipate heat produced by the thin film coil. When the thin film coil produces heat during the recording of information, priority is given to the guidance of the heat to the leading side of the thin film coil, namely, the side opposite to the position of the write shield layer, rather than the guidance of the heat to the trailing side of the thin film coil, namely, the position of the write shield layer, so as to dissipate the heat. Thus, the thin film magnetic head reduces the likelihood of the heat accumulating in the write shield layer, thus reduces the likelihood of the write shield layer expanding thermally, and thus reduces the amount of protrusion of the write shield layer.
    Type: Application
    Filed: August 27, 2004
    Publication date: March 3, 2005
    Applicants: TDK CORPORATION, SAE MAGNETICS (H.K.) LTD.
    Inventors: Naoto Matono, Norikazu Ota, Mitsuo Otsuki
  • Patent number: 6842311
    Abstract: A precise positioning actuator to be fixed to a head slider provided with at least one head element, for precisely positioning the at least one head element includes a base, and a pair of movable arms extending from the base and having slider fixing portions to be fixed to side surfaces of the head slider at top end sections thereof. Each of the pair of movable arms includes an arm member and an actuator layer formed on a side surface of the arm member, for displacing the arm member in response to a drive signal applied thereto. The actuator layer is terminated on the side surface of the arm member at a frontward position from the slider fixing portion.
    Type: Grant
    Filed: March 19, 2002
    Date of Patent: January 11, 2005
    Assignee: TDK Corporation
    Inventors: Norikazu Ota, Takeshi Wada, Takashi Honda
  • Publication number: 20040264048
    Abstract: Provided is a thin film magnetic head capable of preventing unintentional erasing of information during non-recording, thereby ensuring its magnetic operating characteristics with stability. A top read shield layer extends rearward relative to a back gap (or a back-gap rear-end position), and a write shield layer also extends rearward relative to the back gap. Thus, a stray external magnetic field generated from a voice coil motor or the like is more likely to be taken in by not only the top read shield layer but also the write shield layer, that is, the stray external magnetic field is less likely to converge on the top read shield layer. This reduces the likelihood of an undesired magnetic closed loop being formed between the top read shield layer and magnetic pole layer and a recording medium, and thus reduces the likelihood of unintentional overwriting of information taking place during non-recording due to the undesired magnetic closed loop.
    Type: Application
    Filed: March 12, 2004
    Publication date: December 30, 2004
    Applicants: TDK CORPORATION, SAE MAGNETICS (H.K.) LTD.
    Inventors: Naoto Matono, Norikazu Ota
  • Publication number: 20040257706
    Abstract: In the head slider of the present invention, recording and reproducing electrode pads and heater electrode pads are attached to the same surface of an overcoat layer. The heater electrode pads are located on both sides of a group constituted by the recording and reproducing electrode pads. As a consequence, leads for the heater are located between respective leads for recording and reproducing head parts, whereby crosstalk can be prevented from occurring between the leads for the recording and reproducing head parts.
    Type: Application
    Filed: January 27, 2004
    Publication date: December 23, 2004
    Applicant: TDK Corporation
    Inventors: Norikazu Ota, Tetsuro Sasaki, Nobuya Oyama, Soji Koide
  • Publication number: 20040259474
    Abstract: The heaters in the respective thin-film magnetic head in the bar are electrically connected to its neighbors, and a variable resistor is connected to each of the heaters in parallel. The resistance of each of the variable resistors is varied depending on the amount that the medium-opposing surface (ABS) of the thin-film magnetic head is to project. Also, the medium-opposing surface of the thin-film magnetic head in the magnetic head bar is polished while energizing all the heaters by the same power supply.
    Type: Application
    Filed: April 13, 2004
    Publication date: December 23, 2004
    Applicants: TDK CORPORATION, SAE MAGNETICS (H.K.) LTD.
    Inventors: Nobuya Oyama, Norikazu Ota, Soji Koide, Tetsuro Sasaki, Osamu Fukuroi
  • Publication number: 20040235394
    Abstract: A thin-film magnetic head is formed on a support and is provided with a reproducing head part, a recording head part, and a heater for generating heat upon energization. A medium-opposing surface S of the magnetic head is polished while energizing the heater or recording head part.
    Type: Application
    Filed: March 3, 2004
    Publication date: November 25, 2004
    Applicant: TDK CORPORATION
    Inventors: Norikazu Ota, Takehiro Kamigama, Nobuya Oyama, Soji Koide, Tetsuro Sasaki
  • Publication number: 20040228033
    Abstract: A write head of a magnetic head for vertical magnetic recording comprises: a coil; a main pole layer that allows the magnetic flux corresponding to the magnetic field generated by the coil to pass therethrough and generates a write magnetic field; an auxiliary pole layer; a gap layer provided between the main pole layer and the auxiliary pole layer; and a yoke layer for magnetically coupling the main pole layer to the auxiliary pole layer. The main pole layer has a flat top surface. In the main pole layer the position in which the thickness starts to increase is located between the medium facing surface and the position in which the width starts to increase.
    Type: Application
    Filed: April 27, 2004
    Publication date: November 18, 2004
    Applicant: TDK CORPORATION
    Inventors: Susumu Aoki, Yasuyuki Notsuke, Yuichi Watabe, Norikazu Ota, Tetsuya Roppongi
  • Publication number: 20040201920
    Abstract: A thin-film magnetic head has at least either an electromagnetic transducer or a magnetoresistive device, and a sheet-shaped heater for generating heat when energized. The heater has a heating part and a lead part connected in series to the heating part. The lead part has a sheet resistance lower than that of the heating part.
    Type: Application
    Filed: April 9, 2004
    Publication date: October 14, 2004
    Applicant: TDK Corporation
    Inventors: Soji Koide, Nobuya Oyama, Norikazu Ota, Tetsuro Sasaki
  • Publication number: 20040190197
    Abstract: Provided is a thin film magnetic head capable of securing recording characteristics even in the case where a return pole layer is disposed on a medium-outgoing side of the pole layer. The return yoke layer is disposed on a trailing side of the pole layer, and a neck height NH is within a range of NH≦W1 (a width of a front end portion in a main pole layer)+0.05 &mgr;m, and a height ratio (a ratio of the neck height NH to a throat height TH) NH/TH is within a range of 0.5<NH/TH<1.6. Thereby, the neck height NH and the height ratio NH/TH which have an influence on the recording characteristics can become appropriate, so even if the thickness of the gap layer is 0.2 &mgr;m or less to bring the return yoke layer closer to the pole layer, overwrite characteristics can be secured.
    Type: Application
    Filed: March 22, 2004
    Publication date: September 30, 2004
    Applicants: TDK CORPORATION, SAE MAGNETICS (H.K.) LTD.
    Inventors: Yuichi Watabe, Norikazu Ota, Yasuyuki Notsuke, Susumu Aoki, Tetsuya Roppongi, Naoto Matono
  • Publication number: 20040184192
    Abstract: A magnetic head part is constituted by a reproducing head part having a GMR device and a recording head part acting as an inductive electromagnetic transducer which are laminated on a support. The magnetic head part further comprises a heater. One of poles of the heater is electrically connected to a heater electrode pad disposed on a first surface of a head slider. The other pole is electrically connected to a substrate constituting the support, and is energized by way of a second surface of the head slider.
    Type: Application
    Filed: March 15, 2004
    Publication date: September 23, 2004
    Applicant: TDK CORPORATION
    Inventors: Norikazu Ota, Tetsuro Sasaki, Nobuya Oyama, Soji Koide
  • Publication number: 20040179299
    Abstract: A heater member is formed in structure including a heater layer with a low electrical resistivity and a cap layer with a higher electrical resistivity, an electrically conductive electrode film is formed thereon, and electrically conductive bumps are formed thereon by plating. Unnecessary part of the electrode film is removed using the bumps as a mask. The heater member generates heat to thermally expand a thin-film magnetic head, whereby the distance is reduced between a recording medium and, a magnetoresistive device and/or an electromagnetic conversion device. During removal of the electrode film part of the cap layer with the higher electrical resistivity in the heater member is removed together with the electrode film, which reduces the variation in the total resistance of the heater member.
    Type: Application
    Filed: February 24, 2004
    Publication date: September 16, 2004
    Applicant: TDK CORPORATOIN
    Inventors: Tetsuro Sasaki, Nobuya Oyama, Soji Koide, Norikazu Ota
  • Publication number: 20040165312
    Abstract: A thin-film magnetic head on a support includes an electromagnetic transducer for writing, a magnetoresistive device for reading, an overcoat layer and a heating element. The transducer and magnetoresistive device are disposed on the support. The overcoat layer is disposed at the opposite side of them from the support. The heating element is provided in the overcoat layer and generates heat when energized.
    Type: Application
    Filed: February 19, 2004
    Publication date: August 26, 2004
    Applicant: TDK CORPORATION
    Inventors: Soji Koide, Norikazu Ota, Nobuya Oyama, Tetsuro Sasaki
  • Publication number: 20040165311
    Abstract: A thin-film magnetic head comprises at least one of a magnetoresistive device for reading and an electromagnetic transducer device for writing, and a heating element provided in the head body part. The heating element has an up portion meandering between an origin and a halfway point and a down portion meandering along the up portion from the halfway point to an end positioned in the vicinity of the origin, and adapted to generate heat when energized.
    Type: Application
    Filed: February 17, 2004
    Publication date: August 26, 2004
    Applicant: TDK CORPORATION
    Inventors: Noboru Yamanaka, Norikazu Ota
  • Publication number: 20040130820
    Abstract: A flying type thin-film magnetic head includes a write head element with a coil conductor and a yoke, a write current flowing through the coil conductor, an overcoat layer laminated on the write head element, and a heat-block layer formed in the overcoat layer and made of a material with a heat conductivity that is lower than a heat conductivity of the overcoat layer.
    Type: Application
    Filed: December 16, 2003
    Publication date: July 8, 2004
    Applicant: TDK Corporation
    Inventor: Norikazu Ota