Patents by Inventor Tetsuya Roppongi

Tetsuya Roppongi 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: 20110317313
    Abstract: An orthogonalizing bias function part formed at a rear part of an MR part in a DFL structure influencing a substantial orthogonalizing function of first and second ferromagnetic layers in respective magnetization directions thereof, non-magnetic metal layers formed to abut both ends of the MR part in a width direction and separated from both ends of the MR part by respective insulation layers, each of the non-magnetic metal layers being in a two-layer structure configured with a first non-magnetic metal layer positioned at a lower side as a lower layer and a second non-metal layer positioned at an upper side as an upper layer are configured, and relationship R2<R1 is met, where R1 is a milling rate for the first non-magnetic metal layer that is the lower layer, and R2 is another milling rate for the second non-magnetic metal layer that is the upper layer.
    Type: Application
    Filed: June 28, 2010
    Publication date: December 29, 2011
    Applicant: TDK CORPORATION
    Inventors: Daisuke MIYAUCHI, Keita KAWAMORI, Takahiko MACHITA, Tetsuya ROPPONGI
  • Patent number: 8077559
    Abstract: An outer surface of a plasmon generator includes: a plasmon exciting part that faces an evanescent light generating surface with a predetermined distance therebetween; and a front end face located in a medium facing surface. The plasmon generator has: first and second sidewall parts that are connected to the plasmon exciting part and increase in distance from each other with increasing distance from the plasmon exciting part; and at least one extended portion connected to an edge of at least one of the first and second sidewall parts opposite from the plasmon exciting part. A magnetic pole has a portion interposed between the first and second sidewall parts. The front end face includes first and second portions lying at ends of the first and second sidewall parts and connected to each other into a V-shape. An end face of the magnetic pole has a portion interposed between the first and second portions of the front end face.
    Type: Grant
    Filed: June 25, 2010
    Date of Patent: December 13, 2011
    Assignee: TDK Corporation
    Inventors: Daisuke Miyauchi, Tetsuya Roppongi, Kosuke Tanaka, Susumu Aoki, Katsuki Kurihara
  • Patent number: 8077558
    Abstract: A plasmon generator has an outer surface including a plasmon exciting part that faces an evanescent light generating surface of a waveguide. The outer surface further includes first and second inclined surfaces that increase in distance from each other with increasing distance from the plasmon exciting part, and a front end face. The front end face has first and second portions that are connected to each other into a V-shape. The first portion includes a first side lying at an end of the first inclined surface. The second portion includes a second side lying at an end of the second inclined surface. An angle formed between a lower part of the first side and a lower part of the second side is smaller than that formed between an upper part of the first side and an upper part of the second side.
    Type: Grant
    Filed: May 24, 2010
    Date of Patent: December 13, 2011
    Assignee: TDK Corporation
    Inventors: Takeshi Tsutsumi, Daisuke Miyauchi, Tetsuya Roppongi, Kosuke Tanaka, Susumu Aoki, Takahiko Izawa, Tsutomu Chou
  • Publication number: 20110286128
    Abstract: A plasmon generator has an outer surface including a plasmon exciting part that faces an evanescent light generating surface of a waveguide. The outer surface further includes first and second inclined surfaces that increase in distance from each other with increasing distance from the plasmon exciting part, and a front end face. The front end face has first and second portions that are connected to each other into a V-shape. The first portion includes a first side lying at an end of the first inclined surface. The second portion includes a second side lying at an end of the second inclined surface. An angle formed between a lower part of the first side and a lower part of the second side is smaller than that formed between an upper part of the first side and an upper part of the second side.
    Type: Application
    Filed: May 24, 2010
    Publication date: November 24, 2011
    Applicant: TDK CORPORATION
    Inventors: Takeshi TSUTSUMI, Daisuke MIYAUCHI, Tetsuya ROPPONGI, Kosuke TANAKA, Susumu AOKI, Takahiko IZAWA, Tsutomu CHOU
  • Patent number: 8064163
    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: Grant
    Filed: January 22, 2008
    Date of Patent: November 22, 2011
    Assignee: TDK Corporation
    Inventors: Norikazu Ota, Tetsuya Roppongi, Yuichi Watabe
  • Publication number: 20110248710
    Abstract: A measuring circuit system in a magnetic field measuring apparatus of the invention has an amplifier and a band-pass filter connected in sequence on an output terminal side of the TMR element, the band-pass filter is a narrow-range band-pass filter such that a peak pass frequency of the filter that is a center is a basic frequency selected from a range of 10 to 40 GHz and a band width centered around the basic frequency is a narrow range of ±0.5 to ±4 GHz; and with the measuring circuit system, an SIN ratio (SNR) of 3 dB or greater is obtained, the SNR being defined by a ratio of an amplitude S of a high-frequency generated signal induced by the TMR element to a total noise N that is a sum of a head noise generated by the TMR element and a circuit noise generated by the amplifier. With such a configuration, an in-plane high-frequency magnetic field generated by a microwave-assisted magnetic head is reliably and precisely measured.
    Type: Application
    Filed: April 7, 2010
    Publication date: October 13, 2011
    Applicant: TDK CORPORATION
    Inventors: Isamu SATO, Hiroshi Ikeda, Mikio Matsuzaki, Tetsuya Roppongi, Noboru Yamanaka, Tsutomu Aoyama
  • Publication number: 20110228419
    Abstract: A plasmon generator has an outer surface including a propagation edge, and has a near-field light generating part lying at an end of the propagation edge and located in a medium facing surface. The propagation edge faces an evanescent light generating surface of a waveguide's core with a predetermined distance therebetween and extends in a direction perpendicular to the medium facing surface. The propagation edge is arc-shaped in a cross section parallel to the medium facing surface. The plasmon generator includes a shape changing portion in which a radius of curvature of the propagation edge in the cross section parallel to the medium facing surface continuously decreases with decreasing distance to the medium facing surface.
    Type: Application
    Filed: March 22, 2010
    Publication date: September 22, 2011
    Applicant: TDK CORPORATION
    Inventors: Kosuke Tanaka, Daisuke Miyauchi, Susumu Aoki, Tetsuya Roppongi, Tsutomu Chou, Shinji Hara, Eiji Komura
  • Publication number: 20110222185
    Abstract: A magnetic recording apparatus includes a magnetic recording medium having a magnetic recording layer, a thin-film magnetic head with a microwave-band magnetic drive function, the head having a write field generation means that generates a write field to the magnetic recording medium in response to a write signal, and a microwave generator that is provided independent of the write field generation means and generates an alternating magnetic field in plane having a microwave-band frequency when microwave-excitation current is fed, an excitation current generation means that generates the microwave-excitation current by amplitude-modulating microwave carrier current with a modulating signal having a fixed period, and a write signal supply means that generates the write signal and applies it to the write field generation means of the thin-film magnetic head.
    Type: Application
    Filed: March 10, 2010
    Publication date: September 15, 2011
    Applicant: TDK Corporation
    Inventors: Tetsuya Roppongi, Takuya Adachi, Isamu Sato, Hiroshi Ikeda, Mikio Matsuzaki
  • Publication number: 20110176398
    Abstract: A thermally-assisted magnetic recording head includes a waveguide through which a light for exciting surface plasmon propagates, a near-field optical device configured to be coupled with the light in a surface plasmon mode and to emit near-field light from a near-field-light-generating end surface that forms a portion of an opposed-to-medium surface, and a magnetic pole for generating write field from its end on the opposed-to-medium surface side. The near-field optical device includes a contact-to-waveguide surface having a contact to the waveguide, and a propagation edge provided on a side opposite to the contact-to-waveguide surface, extending to the near-field-light-generating end surface, and configured to propagate there on the surface plasmon excited by the light.
    Type: Application
    Filed: January 15, 2010
    Publication date: July 21, 2011
    Applicant: TDK Corporation
    Inventors: Kosuke Tanaka, Daisuke Miyauchi, Susumu Aoki, Tetsuya Roppongi, Tsutomu Chou, Takahiko Izawa, Katsuki Kurihara
  • Patent number: 7983009
    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: Grant
    Filed: May 17, 2007
    Date of Patent: July 19, 2011
    Assignee: TDK Corporation
    Inventors: Norikazu Ota, Tetsuya Roppongi
  • Patent number: 7974046
    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: Grant
    Filed: October 17, 2007
    Date of Patent: July 5, 2011
    Assignee: TDK Corporation
    Inventors: Norikazu Ota, Tetsuya Roppongi, Hiraku Hirabayashi, Yuichi Watabe
  • Patent number: 7920357
    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: Grant
    Filed: October 9, 2007
    Date of Patent: April 5, 2011
    Assignee: TDK Corporation
    Inventors: Isamu Sato, Tetsuya Roppongi, Yuichi Watabe, Norikazu Ota, Hiroshi Ikeda, Mikio Matsuzaki
  • Publication number: 20110058272
    Abstract: Provided is a thermally-assisted magnetic recording head capable of setting the near-field light (NFL-) emission point to be sufficiently close to the write-field-generating portion. The head comprises a magnetic pole, a waveguide propagating light, and a NFL-generator coupled with the light in surface plasmon mode. The NFL-generator comprises a propagation edge extending to the NFL-generating end surface, at least a portion of the propagation edge being opposed to the waveguide with a distance, and the magnetic pole has a surface contact with a surface portion of the NFL-generator including no propagation edge. Therefore, the distance between the magnetic-pole end surface and the NFL-generating end surface becomes zero. The propagation edge is not contacted with the magnetic pole. Accordingly, the surface plasmon can propagate along on the propagation edge without being absorbed by the pole. Thus, the NFL-emission point is ensured to be at the end point of the propagation edge.
    Type: Application
    Filed: September 10, 2009
    Publication date: March 10, 2011
    Applicant: TDK Corporation
    Inventors: Daisuke Miyauchi, Tsutomu Chou, Kosuke Tanaka, Susumu Aoki, Tetsuya Roppongi, Katsuki Kurihara
  • Patent number: 7885029
    Abstract: A head capable of favorite thermally-assisted magnetic recording without depending on the use of a near-field light generator is provided. The head comprises a write head element formed on the trailing side from a waveguide and comprising a first main pole. The first main pole and the waveguide are opposed to each other through a first clad layer, and a second clad layer is provided on a rear side from the first main pole. This gives that the end surface of the waveguide can be placed much close to the end surface of the first main pole apart by only a thickness of the first clad layer. As a result, the end surface of the first main pole can apply a sufficient intensity of write field to the intensity center and its vicinity of the light spot formed on the magnetic recording layer.
    Type: Grant
    Filed: April 14, 2009
    Date of Patent: February 8, 2011
    Assignee: TDK Corporation
    Inventors: Daisuke Miyauchi, Susumu Aoki, Seiichi Takayama, Koji Shimazawa, Tetsuya Roppongi
  • Patent number: 7872831
    Abstract: The invention provides a thin-film magnetic head wherein the combined release angle ? for a dominant recording magnetic field generated from a magnetic pole layer toward a patterned media for the purpose of recording magnetic information is set to within an angle range of 35° to 65° with respect to a patterned media surface. It is thus possible to invert, with efficiency and reliability, the directions of magnetization of isolate bits lined up on the patterned media for high-density recording.
    Type: Grant
    Filed: May 31, 2007
    Date of Patent: January 18, 2011
    Assignee: TDK Corporation
    Inventors: Kei Hirata, Tetsuya Roppongi, Kiyoshi Noguchi
  • Publication number: 20100302672
    Abstract: A magnetic recording head capable of a satisfying thermally-assisted magnetic recording without depending on the use of a near-field light generator is provided. The head comprises a waveguide and a main magnetic pole having a main pole tip. Further, at least a portion of the main pole tip is embedded in a groove provided in the upper surface of the waveguide. Further, a second clad layer is provided on the first clad layer and on a rear side from the main pole tip. This configuration of the first and second clad layers suppresses the absorption of the light propagating through the waveguide by the main magnetic pole. Further, the configuration in which at least a portion of the main pole tip is embedded in the groove can cause the distance between the light spot center of the waveguide and the main magnetic pole to be sufficiently small.
    Type: Application
    Filed: May 26, 2009
    Publication date: December 2, 2010
    Applicant: TDK CORPORATION
    Inventors: Susumu AOKI, Daisuke MIYAUCHI, Seiichi TAKAYAMA, Koji SHIMAZAWA, Tetsuya ROPPONGI
  • Patent number: 7843667
    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: Grant
    Filed: May 21, 2007
    Date of Patent: November 30, 2010
    Assignee: 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
  • Publication number: 20100259845
    Abstract: A head capable of favorite thermally-assisted magnetic recording without depending on the use of a near-field light generator is provided. The head comprises a write head element formed on the trailing side from a waveguide and comprising a first main pole. The first main pole and the waveguide are opposed to each other through a first clad layer, and a second clad layer is provided on a rear side from the first main pole. This gives that the end surface of the waveguide can be placed much close to the end surface of the first main pole apart by only a thickness of the first clad layer. As a result, the end surface of the first main pole can apply a sufficient intensity of write field to the intensity center and its vicinity of the light spot formed on the magnetic recording layer.
    Type: Application
    Filed: April 14, 2009
    Publication date: October 14, 2010
    Applicant: TDK CORPORATION
    Inventors: Daisuke MIYAUCHI, Susumu AOKI, Seiichi TAKAYAMA, Koji SHIMAZAWA, Tetsuya ROPPONGI
  • Patent number: 7791838
    Abstract: A magnetic head apparatus is provided which is capable of recording data in a recoding layer having high coercive force with high accuracy without heating. A magnetic recording and reproducing apparatus is also provided which has the magnetic head apparatus. A recording head has: a main magnetic pole; a recording-side front-end shield (a return magnetic pole); a recording-side rear-end shield (a return magnetic pole); a main coil for generating a perpendicular recording magnetic field at the main magnetic pole; and an auxiliary coil for generating a longitudinal alternating current magnetic field having a frequency in the microwave band at the main magnetic pole.
    Type: Grant
    Filed: April 26, 2007
    Date of Patent: September 7, 2010
    Assignee: TDK Corporation
    Inventors: Isamu Sato, Yoshikazu Soeno, Koichi Terunuma, Tetsuya Roppongi, Hiroshi Ikeda
  • Patent number: 7554766
    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: Grant
    Filed: December 16, 2005
    Date of Patent: June 30, 2009
    Assignee: TDK Corporation
    Inventors: Norikazu Ota, Tetsuya Roppongi