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: 7522376
    Abstract: Provided is a thin film magnetic head capable of appropriately control the flow of magnetic flux from a yoke layer to a pole layer so as to prevent information from being overwritten without intention during recording. A perpendicular recording system thin film magnetic head is formed so that a portion of a yoke layer and a portion of a pole layer are connected to each other in a connecting surface. When a large amount of the magnetic flux contained in the yoke layer flows into the pole layer through the connecting surface, the large amount of the magnetic flux is concentrated in the connecting surface, so an excessive amount of the magnetic flux is not supplied to a front end portion of the pole layer, and an appropriate amount of the magnetic flux is supplied.
    Type: Grant
    Filed: November 4, 2003
    Date of Patent: April 21, 2009
    Assignee: TDK Corporation
    Inventors: Naoto Matono, Tetsuya Roppongi, Norikazu Ota
  • Publication number: 20090059438
    Abstract: A thin-film magnetic head with a perpendicular magnetic recording structure includes a main pole layer, a nonmagnetic gap layer, and an auxiliary pole layer facing the main pole layer via the nonmagnetic gap layer. A surface of a top end section of the main pole layer has an inclined step that slopes from a lamination plane of the layers. The surface faces a top end section of the auxiliary pole layer. The top end section of the auxiliary pole layer has side shield sections at a position that is not exposed to an ABS. The side shield sections faces at least part of side surfaces in a track-width direction, of the main pole layer so as to cover at least part of the inclined step.
    Type: Application
    Filed: August 31, 2007
    Publication date: March 5, 2009
    Applicant: TDK CORPORATION
    Inventors: Kenkichi ANAGAWA, Norikazu OTA
  • Publication number: 20080297953
    Abstract: A magnetic head includes: a coil; a pole layer; a shield having an end face located in a medium facing surface forward of an end face of the pole layer along a direction of travel of a recording medium; a gap layer between the shield and the pole layer; and a substrate on which the foregoing elements are stacked. The top surface of the pole layer includes: first and second portions with a difference in height therebetween; and a third portion connecting the first and second portions to each other. The first portion has an edge located in the medium facing surface, and the second portion is located farther from the medium facing surface and from the substrate than the first portion. The magnetic head further includes a nonmagnetic layer disposed between the second portion and the gap layer. The nonmagnetic layer has a surface touching the second portion, the surface having an edge located at the boundary between the second and third portions.
    Type: Application
    Filed: June 4, 2007
    Publication date: December 4, 2008
    Applicants: SAE MAGNETICS (H.K.) LTD., TDK CORPORATION
    Inventors: Naoto Matono, Koichi Otani, Tatsuya Harada, Noriaki Kasahara, Takamitsu Sakamoto, Hiroaki Kawashima, Hirotaka Gomi, Kenkichi Anagawa, Norikazu Ota
  • Publication number: 20080291582
    Abstract: Provided is a thin film magnetic head capable of suppressing an occurrence of a track erase, decreasing an influence on a magnetoresistive element caused by a magnetic flux generated from a thin film coil, and further decreasing the parasitic capacity. The thin film magnetic head has, in order in a stacked direction, a first magnetic shield layer, a magnetoresistive element, a second magnetic shield layer, a third magnetic shield layer, a main magnetic pole layer and a return yoke layer. A width in a track width direction of at least one of the first and the second magnetic shield layers is smaller than widths in a track width direction of the third magnetic shield layer and the return yoke layer.
    Type: Application
    Filed: May 21, 2007
    Publication date: November 27, 2008
    Applicant: TDK CORPORATION
    Inventors: Kei Hirata, Norikazu Ota, Yuichi Watabe, Tetsuro Sasaki, Takeo Kagami, Tetsuya Roppongi, Kazuki Sato, Yuji Otsubo, Sohei Horiuchi, Yoshiaki Tanaka, Kenji Yokoyama, Noriaki Kasahara
  • Patent number: 7457080
    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: Grant
    Filed: November 2, 2005
    Date of Patent: November 25, 2008
    Assignee: TDK Corporation
    Inventors: Yuichi Watabe, Susumu Aoki, Reiichi Kurumisawa, Yasuyuki Notsuke, Norikazu Ota
  • Patent number: 7453668
    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: Grant
    Filed: October 18, 2005
    Date of Patent: November 18, 2008
    Assignee: TDK Corporation
    Inventors: Susumu Aoki, Reiichi Kurumisawa, Norikazu Ota, Yasuyuki Notsuke, Yuichi Watabe
  • Patent number: 7433152
    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: Grant
    Filed: March 31, 2006
    Date of Patent: October 7, 2008
    Assignee: TDK Corporation
    Inventors: Yuichi Watabe, Susumu Aoki, Reiichi Kurumisawa, Yasuyuki Notsuke, Norikazu Ota
  • Publication number: 20080218909
    Abstract: Provided is a thin-film magnetic head having a heating element in which excessive increase in temperature is suppressed corresponding to smaller area of the shield layers of the MR effect element. The thin-film magnetic head comprises: an electromagnetic coil element; an MR effect element having two shield layers sandwiching an MR effect multilayer; and a heating element having a heating layer provided at least between the electromagnetic coil element and the MR effect element, and further in the head, at least a portion of a run-off portion of the heating layer running off the shield layer closer to the heating layer than the other shield layer has a resistance per unit length smaller than a resistance per unit length of the other portions than the portion running off the shield layer.
    Type: Application
    Filed: March 8, 2007
    Publication date: September 11, 2008
    Applicant: TDK CORPORATION
    Inventors: Katsuki KURIHARA, Norikazu Ota
  • Patent number: 7420776
    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: December 27, 2006
    Date of Patent: September 2, 2008
    Assignee: TDK Corporation
    Inventors: Noboru Yamanaka, Norikazu Ota
  • Publication number: 20080180858
    Abstract: Provided are a perpendicular magnetic write head capable of achieving the high performance and stability in the writing performance, and a method of manufacturing the same. On a trailing side of a main magnetic pole layer, disposed are a gap layer extending backward from an air bearing surface and an auxiliary magnetic pole layer extending backward from a position recessed from the air bearing surface. The auxiliary magnetic pole layer is partially overlapped on the gap layer. In case the auxiliary magnetic pole layer is formed using etching method in the process of manufacturing the perpendicular magnetic write head, the gap layer has a function as an etching stopper layer so that the main magnetic pole layer is protected; thereby the already-formed main magnetic pole layer is not subjected to etching.
    Type: Application
    Filed: January 22, 2008
    Publication date: July 31, 2008
    Applicant: TDK CORPORATION
    Inventors: Norikazu Ota, Tetsuya Roppongi, Yuichi Watabe
  • Publication number: 20080151436
    Abstract: Provided is a thin-film magnetic head capable of writing data with high accuracy on a magnetic recording medium having high coercive force without heating. The head comprises an electromagnetic coil element comprising: a main magnetic pole; an auxiliary magnetic pole; and a write coil formed so as to pass through at least between the main magnetic pole and the auxiliary magnetic pole, for generating the write magnetic field. In this head, a part of the write coil has a layered structure of: a resonance coil layer for generating a resonance magnetic field having ferromagnetic resonance frequency of a magnetic recording layer of a magnetic recording medium or having a frequency in the vicinity thereof; and a write coil layer. And further, the resonance coil layer and the write coil layer sandwich an insulating layer therebetween.
    Type: Application
    Filed: October 9, 2007
    Publication date: June 26, 2008
    Applicant: TDK CORPORATION
    Inventors: Isamu Sato, Tetsuya Roppongi, Yuichi Watabe, Norikazu Ota, Hiroshi Ikeda, Mikio Matsuzaki
  • Patent number: 7391590
    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: Grant
    Filed: August 27, 2004
    Date of Patent: June 24, 2008
    Assignee: TDK Corporation
    Inventors: Naoto Matono, Norikazu Ota, Mitsuo Otsuki
  • Publication number: 20080094755
    Abstract: The present invention provides a thin-film magnetic head which surely improves the writing and reading characteristic with reducing the flying height and surely handles the contact or collision with the magnetic recording medium. A thin-film magnetic head is provided, which includes, an substrate with ABS; a read or write head element provided on an element-formed surface of the substrate; at least one protrusion adjustment portion whose end reaches a slider end surface on the ABS side, which provides on an element-formed surface of the substrate; at least one heating portion provided rear at least one protrusion adjustment portion viewed from the slider end surface on the ABS side.
    Type: Application
    Filed: October 17, 2007
    Publication date: April 24, 2008
    Applicant: TDK CORPORATION
    Inventors: Norikazu OTA, Tetsuya ROPPONGI, Hiraku HIRABAYASHI, Yuichi WATABE
  • Publication number: 20080068749
    Abstract: A thin-film magnetic head that the TPTP phenomenon due to the environment temperature is surely suppressed without providing a new particular component is provided.
    Type: Application
    Filed: June 1, 2007
    Publication date: March 20, 2008
    Applicant: TDK CORPORATION
    Inventors: Katsuki Kurihara, Hiraku Hirabayashi, Norikazu Ota
  • Publication number: 20080043355
    Abstract: Provided is a measuring method of flying height of a thin-film magnetic head, capable of measuring the flying height without using a new component, such as an atmospheric pressure sensor, adverse to a requirement of reduction in cost and size. The measuring method of flying height comprises the steps of: causing a thin-film magnetic head including a read head element receiving a signal magnetic field from a magnetic disk to contact the rotating magnetic disk temporarily; and measuring a flying height of the thin-film magnetic head by measuring outputs from the read head element at a time of the contact and during flying of the thin-film magnetic head.
    Type: Application
    Filed: August 10, 2007
    Publication date: February 21, 2008
    Applicant: TDK CORPORATION
    Inventor: Norikazu OTA
  • Publication number: 20070274003
    Abstract: The invention provides a magnetic recording/reproducing system constructed such that until the skew angle is past the maximum skew angle ?max, the edges of the write shield layer and the edges of the lower read shield layer do not overlap on the same track, so that upon application of an external magnetic field, the already written signals are kept back from degradation.
    Type: Application
    Filed: May 17, 2007
    Publication date: November 29, 2007
    Applicant: TDK Corporation
    Inventors: Norikazu OTA, Tetsuya ROPPONGI
  • Patent number: 7283328
    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: Grant
    Filed: April 26, 2005
    Date of Patent: October 16, 2007
    Assignee: TDK Corporation
    Inventors: Norikazu Ota, Kenji Inage, Taro Oike
  • Patent number: 7253993
    Abstract: A head slider with a precise positioning actuator includes a thin plane shaped head section provided with a first surface that is substantially perpendicular to an ABS of the head slider, a second surface opposite to the first surface and at least one head element formed on the first surface, and an actuator section located at a side of the second surface of the head section and integrally fixed to the head section, for precisely positioning the at least one head element.
    Type: Grant
    Filed: February 25, 2002
    Date of Patent: August 7, 2007
    Assignees: TDK Corporation, SAE Magnetics (H.K.) Ltd.
    Inventors: Takeshi Wada, Masashi Shiraishi, Takashi Honda, Norikazu Ota
  • Patent number: 7245454
    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: Grant
    Filed: April 27, 2004
    Date of Patent: July 17, 2007
    Assignee: TDK Corporation
    Inventors: Susumu Aoki, Yasuyuki Notsuke, Yuichi Watabe, Norikazu Ota, Tetsuya Roppongi
  • 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