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).

  • Patent number: 7218475
    Abstract: A thin film magnetic head capable of preventing unintentional erasing of information during non-recording, 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; 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: Grant
    Filed: March 12, 2004
    Date of Patent: May 15, 2007
    Assignees: TDK Corporation, SAE Magnetics (H.K.) Ltd.
    Inventors: Naoto Matono, Norikazu Ota
  • Publication number: 20070103814
    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: December 27, 2006
    Publication date: May 10, 2007
    Applicant: TDK CORPORATION
    Inventors: Noboru Yamanaka, Norikazu Ota
  • Patent number: 7203035
    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: Grant
    Filed: April 9, 2004
    Date of Patent: April 10, 2007
    Assignee: TDK Corporation
    Inventors: Soji Koide, Nobuya Oyama, Norikazu Ota, Tetsuro Sasaki
  • Patent number: 7187521
    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: Grant
    Filed: February 17, 2004
    Date of Patent: March 6, 2007
    Assignee: TDK Corporation
    Inventors: Noboru Yamanaka, Norikazu Ota
  • Patent number: 7184246
    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: Grant
    Filed: February 24, 2004
    Date of Patent: February 27, 2007
    Assignee: TDK Corporation
    Inventors: Tetsuro Sasaki, Nobuya Oyama, Soji Koide, Norikazu Ota
  • Patent number: 7180707
    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: Grant
    Filed: February 19, 2004
    Date of Patent: February 20, 2007
    Assignee: TDK Corporation
    Inventors: Soji Koide, Norikazu Ota, Nobuya Oyama, Tetsuro Sasaki
  • Publication number: 20060291098
    Abstract: A thin-film magnetic head that has an improved protrusion efficiency under the condition of not only assuring the reliability of the-heating operation, but also stabilizing the read output is provided. The head comprises: a magnetic head element for writing and/or reading data signals; a heating element for generating heat at least during operations of the magnetic head element; and a first heatsink element provided adjacent to the heating element for receiving a part of the heat generated from the heating element, the first heatsink element being a distance from the magnetic head element.
    Type: Application
    Filed: January 18, 2006
    Publication date: December 28, 2006
    Inventors: Norikazu Ota, Katsuki Kurihara, Hiraku Hirabayashi, Taro Oike, Hiroki Matsukuma
  • Patent number: 7154707
    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 ?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 ?m or less to bring the return yoke layer closer to the pole layer, overwrite characteristics can be secured.
    Type: Grant
    Filed: March 22, 2004
    Date of Patent: December 26, 2006
    Assignees: TDK Corporation, SAE Magnetics (H.K) Ltd.
    Inventors: Yuichi Watabe, Norikazu Ota, Yasuyuki Notsuke, Susumu Aoki, Tetsuya Roppongi, Naoto Matono
  • Publication number: 20060256472
    Abstract: A write shield layer that forms a part of a thin-film magnetic head is set with respect to the widthwise full length W thereof lying substantially on an air bearing surface that is opposite to the recording medium such that when the full length W is trisected, the maximum thickness H1/3side thereof in a range of widthwise ?W size positioned at both ends thereof is larger than the average thickness Hm of the whole write shield layer from the air bearing surface up to the rear (H1/3side>Hm), so that the so-called external magnetic field resistance is improved, and inadvertent erasure of the information already recorded in the recording medium is avoided as much as possible. Besides, the PTP (pole tip protrusion) phenomenon arising from the generation of heat from coils, and external temperature changes can be held back.
    Type: Application
    Filed: May 3, 2006
    Publication date: November 16, 2006
    Applicant: TDK CORPORATION
    Inventors: Hiraku HIRABAYASHI, Norikazu Ota
  • Patent number: 7113369
    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: Grant
    Filed: January 27, 2004
    Date of Patent: September 26, 2006
    Assignee: TDK Corporation
    Inventors: Norikazu Ota, Tetsuro Sasaki, Nobuya Oyama, Soji Koide
  • Patent number: 7110219
    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: Grant
    Filed: December 16, 2003
    Date of Patent: September 19, 2006
    Assignee: TDK Corporation
    Inventor: Norikazu Ota
  • Patent number: 7102856
    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: Grant
    Filed: July 9, 2004
    Date of Patent: September 5, 2006
    Assignee: TDK Corporation
    Inventors: Soji Koide, Norikazu Ota, Nobuya Oyama, Tetsuro Sasaki
  • Patent number: 7086931
    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: Grant
    Filed: April 13, 2004
    Date of Patent: August 8, 2006
    Assignees: TDK Corporation, SAE Magnetics (H.K.) Ltd.
    Inventors: Nobuya Oyama, Norikazu Ota, Soji Koide, Tetsuro Sasaki, Osamu Fukuroi
  • Publication number: 20060171072
    Abstract: A perpendicular magnetic recording head capable of minimizing the possibility of erasing recorded information without intention at the time of recording information is provided. A pole layer has a structure in which a main pole layer disposed on a leading side and an auxiliary pole layer disposed on a trailing side are laminated. Even if a part of a magnetic flux contained in the auxiliary pole layer is directly emitted from an air bearing surface to outside not via the main pole layer, as the magnetic flux is contained in the magnetic layer, the magnetic flux is not easily emitted from the air bearing surface to the outside directly. Therefore, an unnecessary perpendicular magnetic field is not easily generated by the magnetic flux. Thereby, a recording medium is not easily magnetized again by the unnecessary magnetic field, so information recorded on the recording medium is not easily erased without intention.
    Type: Application
    Filed: March 31, 2006
    Publication date: August 3, 2006
    Applicant: TDK CORPORATION
    Inventors: Yuichi Watabe, Susumu Aoki, Reiichi Kurumisawa, Yasuyuki Notsuke, Norikazu Ota
  • Publication number: 20060158779
    Abstract: A magnetic head for perpendicular magnetic recording comprises: a pole layer, a write shield layer, and a gap layer provided between the pole layer and the write shield layer. The pole layer incorporates a track width defining portion and a wide portion. The track width defining portion has an end located in a medium facing surface and defines the track width. The wide portion is coupled to the other end of the track width defining portion and has a width greater than the width of the track width defining portion. The value of NH×TH/WG is greater than zero and smaller than or equal to 0.85 ?m, where NH is the distance from the medium facing surface to the boundary between the track width defining portion and the wide portion, WG is the space between the pole layer and the write shield layer taken in the medium facing surface, and TH is the distance from the medium facing surface to a point at which the space between the pole layer and the write shield layer starts to be greater than WG.
    Type: Application
    Filed: December 16, 2005
    Publication date: July 20, 2006
    Applicant: TDK Corporation
    Inventors: Norikazu Ota, Tetsuya Roppongi
  • Publication number: 20060126222
    Abstract: The present invention provides a method of manufacturing a thin film magnetic head capable of assuring recording characteristics by determining throat height with high precision. A TH specifying layer is formed so as to extend to a position P1 while being adjacent to a gap layer, and an auxiliary insulating layer is similarly formed so as to extend from the position P1 while being adjacent to the gap layer and specify throat height on the basis of the position P1. After that, a main insulating layer is formed so as to cover a thin film coil on the auxiliary insulating layer, and a yoke layer is formed so as to extend while being partially on the TH specifying layer. The throat height is determined accurately and stably on the basis of the position P1 by the auxiliary insulating layer.
    Type: Application
    Filed: October 18, 2005
    Publication date: June 15, 2006
    Applicant: TDK CORPORATION
    Inventors: Susumu Aoki, Reiichi Kurumisawa, Norikazu Ota, Yasuyuki Notsuke, Yuichi Watabe
  • Patent number: 7061719
    Abstract: A thin film magnetic head which has a thin film coil for generating a magnetic flux and a magnetic pole layer for emitting the magnetic flux generated by the thin film coil toward a recording medium. The magnetic pole layer having a stacked structure including a main magnetic pole layer, an auxiliary magnetic pole layer, and a non-magnetic pole layer. The main magnetic pole layer is disposed so as to be exposed in a recording medium facing surface which faces the recording medium. The auxiliary magnetic pole layer has one end face recessed from the recording medium facing surface and which is disposed so as to face a part of the main magnetic pole layer. The non-magnetic layer is disposed so as to be sandwiched between the main magnetic pole layer and the auxiliary magnetic pole layer.
    Type: Grant
    Filed: September 30, 2003
    Date of Patent: June 13, 2006
    Assignees: TDK Corporation, SAE Magnetics (H.K.) Ltd.
    Inventors: Naoto Matono, Norikazu Ota, Yuichi Watabe, Susumu Aoki, Yasuyuki Notsuke
  • Publication number: 20060098338
    Abstract: A perpendicular magnetic recording head capable of minimizing the possibility of erasing recorded information without intention at the time of recording information is provided. A pole layer has a structure in which a main pole layer disposed on a leading side and an auxiliary pole layer disposed on a trailing side are laminated. Even if a part of a magnetic flux contained in the auxiliary pole layer is directly emitted from an air bearing surface to outside not via the main pole layer, as the magnetic flux is contained in the magnetic layer, the magnetic flux is not easily emitted from the air bearing surface to the outside directly. Therefore, an unnecessary perpendicular magnetic field is not easily generated by the magnetic flux. Thereby, a recording medium is not easily magnetized again by the unnecessary magnetic field, so information recorded on the recording medium is not easily erased without intention.
    Type: Application
    Filed: November 2, 2005
    Publication date: May 11, 2006
    Applicant: TDK CORPORATION
    Inventors: Yuichi Watabe, Susumu Aoki, Reiichi Kurumisawa, Yasuyuki Notsuke, Norikazu Ota
  • Publication number: 20060077591
    Abstract: A thin-film magnetic head with a higher protrusion efficiency is provided, which comprises: a substrate with an air bearing surface (ABS); a read head element including a lower and upper shield layers, and a write head element including a magnetic pole layer; a heating element provided in a position opposite to the ABS in relation to the read and write head elements; and a heatsink element including a heatsink layer provided adjacent to an end opposite to an end in the ABS side of at least one layer of the lower and upper shield layers and the magnetic pole layer, the heatsink element having a shape that a pattern width in the track-width direction of an end portion in the ABS side is larger than a pattern width in the track-width direction of an end portion opposite to the end portion in the ABS side.
    Type: Application
    Filed: August 31, 2005
    Publication date: April 13, 2006
    Applicant: TDK Corporation
    Inventors: Katsuki Kurihara, Taro Oike, Hiraku Hirabayashi, Norikazu Ota
  • Patent number: 7023668
    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: Grant
    Filed: November 24, 2004
    Date of Patent: April 4, 2006
    Assignee: TDK Corporation
    Inventors: Norikazu Ota, Takeshi Wada, Takashi Honda