Patents by Inventor Toshinori Watanabe

Toshinori Watanabe 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: 6898055
    Abstract: A thin-film magnetic head has a second lower core layer sandwiched between a magnetic pole laminate, which is formed of a lower magnetic pole layer, a gap layer, and an upper magnetic pole layer laminated in this order from bottom to top, and a first lower core layer. Unlike a conventional thin-film magnetic head, this thin-film magnetic head does not include a gap depth defining layer. This arrangement makes it possible to easily form the magnetic pole laminate into a substantially rectangular shape, and solves the problems with the conventional thin-film magnetic head attributable to the presence of the gap depth defining layer, the problems being typically represented by a curved gap layer or a reduced volume of the upper magnetic pole layer. Thus, the intensity of a recording magnetic field in the vicinity of a gap can be stabilized and increased, allowing the manufacture of thin-film magnetic heads capable of successfully achieving narrower tracks.
    Type: Grant
    Filed: October 22, 2002
    Date of Patent: May 24, 2005
    Assignee: Alps Electric Co., Ltd.
    Inventors: Kiyoshi Sato, Toshinori Watanabe
  • Publication number: 20050083608
    Abstract: A magnetic head has a reading portion HR and a perpendicular magnetic recording head H1 formed thereon. A first coil layer is formed between the reading portion HR and one magnetic portion of a first magnetic portion and a second magnetic portion, the first magnetic portion and the second magnetic portion forming the perpendicular magnetic recording head H1. A second coil layer is formed between the above one magnetic portion and the other magnetic portion, and joined to form a helical coil layer around the above one magnetic portion.
    Type: Application
    Filed: October 13, 2004
    Publication date: April 21, 2005
    Inventor: Toshinori Watanabe
  • Publication number: 20050036237
    Abstract: A thin-film magnetic head includes a magnetic pole, a magnetic circuit unit separate from the magnetic pole, and a coil layer. The magnetic pole has a predetermined shape in which the width of the bottom surface of an upper magnetic pole layer is larger than the width of the top surface of a lower magnetic pole layer. The core layer is disposed at the back in the height direction of the magnetic pole.
    Type: Application
    Filed: August 5, 2004
    Publication date: February 17, 2005
    Inventors: Hisayuki Yazawa, Toshinori Watanabe
  • Publication number: 20040207282
    Abstract: Disclosed is an electric rotating machine comprising a rotor having N and S poles, a stator including an annular stator core and slots, and multiple-phase stator windings embedded in the slots; wherein the stator windings are formed by winding continuous wires such that straight parts of the stator windings pressed in a flat shape are wound in rings around a cylindrical member provided with grooves. The cylindrical member is inserted into a bore defined by the annular stator core so that the grooves of the cylindrical member are arranged opposite to the slots. The sets of the windings are folded back alternately outside the slots of the stator core and are wound such that the sets of the windings are embedded alternately in the direction of the depth of the slots. Leading and trailing ends of the continuous wires are superposed after being wound at least one turn around the circumferentially arranged slots of the stator.
    Type: Application
    Filed: April 15, 2004
    Publication date: October 21, 2004
    Inventors: Toshiaki Ueda, Yoshimi Mori, Masaki Okamura, Sakae Ishida, Toshinori Watanabe
  • Patent number: 6768611
    Abstract: In a thin film magnetic head, a face surface faces a recording medium and a front surface of an upper core layer is a curved surface which gradually retreats in a height direction generally perpendicular to the face surface as it approaches both sides thereof, and the thickness of the upper core layer gradually increases in the height direction. It is thus possible to appropriately suppress the occurrence of side fringing, efficiently cause a magnetic flux to flow from the upper core layer to an upper pole layer, and make the thin film magnetic head adaptable to a higher recording density.
    Type: Grant
    Filed: March 8, 2001
    Date of Patent: July 27, 2004
    Assignee: Alps Electric Co., Ltd.
    Inventors: Kiyoshi Sato, Toshinori Watanabe, Hideki Gochou, Kiyoshi Kobayashi, Toru Takahashi, Hisayuki Yazawa, Masaki Ikegami
  • Patent number: 6751054
    Abstract: A thin-film magnetic head for perpendicular magnetic recording comprising an auxiliary magnetic pole layer; a main magnetic pole layer; a conductive coil layer in a spiral shape which is disposed between the main magnetic pole layer and the auxiliary magnetic pole layer and which cross the magnetic circuit; and insulating layers electrically insulating the auxiliary magnetic pole layer and the main magnetic pole layer from the conductive coil layer. The insulating layers have flat surfaces formed at the sides further from the auxiliary magnetic pole layer, the front end portion of the main magnetic pole layer is provided on one of the flat surfaces, and the conductive coil layer is disposed under the main magnetic pole layer so that a part of the conductive coil layer opposes the front end portion of the main magnetic pole layer.
    Type: Grant
    Filed: July 11, 2001
    Date of Patent: June 15, 2004
    Assignee: Alps Electric Co., Ltd.
    Inventors: Kiyoshi Sato, Toshinori Watanabe, Toshihiro Kuriyama
  • Patent number: 6751053
    Abstract: A thin-film magnetic head includes a lower core layer, a gap layer, an upper pole layer, and an upper core layer. At the joint between the upper pole layer and the upper core layer, the width of the upper core layer is larger than the width of the upper pole layer, and also the inner end of the upper core layer is located at the back of the inner end of the upper pole layer. Alternatively, a thin-film magnetic head includes a lower core layer, a recording core, an upper core layer, a coil, and a magnetic intermediate layer. The magnetic intermediate layer has a higher saturation flux density than that of the upper core layer. Methods for fabricating thin-film magnetic heads are also disclosed.
    Type: Grant
    Filed: March 30, 2001
    Date of Patent: June 15, 2004
    Assignee: Alps Electric Co., Ltd.
    Inventors: Toshinori Watanabe, Kiyoshi Sato, Kiyoshi Kobayashi, Masaki Ikegami
  • Publication number: 20040095676
    Abstract: A thin-film magnetic head includes a lower core layer; a recording core formed on the lower core layer and exposed at a face surface facing a recording medium, the recording core including a gap layer, an upper pole layer, and optionally, a lower pole layer; an upper core layer magnetically coupled to the upper pole layer; and a coil. A tip surface of the upper core layer at the face surface is set back from the face surface in the height direction, and the tip surface is an inclined surface or a curved surface in which the depth gradually increases from the track width direction. A method for fabricating a thin-film magnetic head is also disclosed.
    Type: Application
    Filed: March 8, 2001
    Publication date: May 20, 2004
    Inventors: Kiyoshi Sato, Toshinori Watanabe, Hideki Gochou, Kiyoshi Kobayashi, Toru Takahashi, Hisayuki Yazawa, Masaki Ikegami, Hiromi Ikegami, Chiaki Ikegami
  • Patent number: 6738223
    Abstract: A thin-film magnetic head has a lower magnetic pole section including a front portion close to a face of the head opposing a recording medium. The front portion has side faces flush with side faces of an upper magnetic core layer formed above the lower magnetic pole section. The lower magnetic pole section does not protrude from the sides of the upper magnetic pole layer. A gap depth defining layer is formed above the lower magnetic core layer and under the upper magnetic pole layer below the upper core layer. Side faces of the gap depth defining layer and the lower magnetic pole section are flush with side faces of the upper magnetic pole layer and/or the upper core layer in the track width direction.
    Type: Grant
    Filed: April 29, 2002
    Date of Patent: May 18, 2004
    Assignee: Alps Electric Co., Ltd.
    Inventors: Kiyoshi Sato, Toshinori Watanabe
  • Publication number: 20040090703
    Abstract: A thin film magnetic head wherein a partial insulating layer is formed on a bottom pole layer with a gap layer provided therebetween, the gap depth Gd being regulated by the distance from a surface facing a recording medium to the partial insulating layer. A magnetic flux partially leaks from a tip region of an upper core layer to the bottom pole layer through the partial insulating layer to effectively suppress magnetic saturation of the tip region, thereby improving the NLTS characteristic and PW50 characteristic, and suppressing the occurrence of side fringing.
    Type: Application
    Filed: October 17, 2003
    Publication date: May 13, 2004
    Inventors: Sumihito Morita, Naruaki Oki, Toshinori Watanabe, Hiroko Shinozaki
  • Patent number: 6731458
    Abstract: The leak magnetic field generated from the upper core layer toward the upper magnetic pole layer can concentrate in the vicinity of the gap layer to suppress side-fringing from generating while increasing the overwrite, by making the saturation magnetic flux density Bs1 of the upper magnetic pole layer to be higher than the saturation magnetic flux density Bs2 of the upper core layer, and by directly bonding the upper core layer on the upper magnetic pole layer.
    Type: Grant
    Filed: March 30, 2001
    Date of Patent: May 4, 2004
    Assignee: Alps Electric Co., Ltd.
    Inventors: Toshinori Watanabe, Hisayuki Yazawa
  • Patent number: 6697221
    Abstract: A perpendicular magnetic recording head includes an auxiliary magnetic pole layer exposed at a surface facing a recording medium, a main magnetic pole layer deposited on the auxiliary magnetic pole layer with an insulating layer therebetween, a coil layer for applying a recording magnetic field to the auxiliary magnetic pole layer and the main magnetic pole layer, and a connecting layer placed on the auxiliary magnetic pole layer toward the back from the surface facing the recording medium. At the surface facing the recording medium, the upper base of the main magnetic pole layer is wider than the lower base so that the width in the track width direction of the main magnetic pole layer gradually increases with distance from the auxiliary magnetic pole layer. A method for making such a perpendicular magnetic recording head is also disclosed.
    Type: Grant
    Filed: December 18, 2001
    Date of Patent: February 24, 2004
    Assignee: Alps Electronic Co., Ltd.
    Inventors: Kiyoshi Sato, Toshinori Watanabe, Hideki Gochou, Hisayuki Yazawa, Kiyoshi Kobayashi, Akira Koyama
  • Publication number: 20040021981
    Abstract: A thin film magnetic head wherein a partial insulating layer is formed on a bottom pole layer with a gap layer provided therebetween, the gap depth Gd being regulated by the distance from a surface facing a recording medium to the partial insulating layer. A magnetic flux partially leaks from a tip region of an upper core layer to the bottom pole layer through the partial insulating layer to effectively suppress magnetic saturation of the tip region, thereby improving the NLTS characteristic and PW50 characteristic, and suppressing the occurrence of side fringing.
    Type: Application
    Filed: August 1, 2003
    Publication date: February 5, 2004
    Inventors: Sumihito Morita, Naruaki Oki, Toshinori Watanabe, Hiroko Shinozaki
  • Patent number: 6687084
    Abstract: A main magnetic pole layer is formed on an insulating layer flattened into a high-flatness surface, and a yoke layer having a large film thickness is formed under the main magnetic pole layer independently of the main magnetic pole. The main magnetic pole layer has a front end surface formed in a shape with a width size gradually increasing in a direction of track width as the front end surface departs farther away from an auxiliary magnetic pole layer. A perpendicular magnetic recording head can be provided which can suppress the occurrence of fringing in a recording pattern, and can form the main magnetic pole layer with high pattern accuracy, and can satisfactorily introduce a recording magnetic field to a fore end of the main magnetic pole layer.
    Type: Grant
    Filed: December 18, 2001
    Date of Patent: February 3, 2004
    Assignee: Alps Electric Co., Ltd.
    Inventors: Toru Takahashi, Hisayuki Yazawa, Hideki Gochou, Kiyoshi Kobayashi, Minoru Yamada, Kiyoshi Sato, Toshinori Watanabe
  • Publication number: 20040012884
    Abstract: A thin film magnetic head has coil layer formed in a space surrounded by a lower core layer, a protruding layer and a back gap layer. The top of these layers are planarized to a continuous flat surface. A lower magnetic pole layer, a gap layer, an upper magnetic pole layer and an upper core layer are formed on the flat surface and are precisely formed in a predetermined shape. The track width Tw can also be set to a predetermined dimension by the width of the upper magnetic pole layer at a surface facing the recording medium. Also, the magnetic path can be shortened to improve magnetic properties.
    Type: Application
    Filed: July 16, 2003
    Publication date: January 22, 2004
    Applicant: Alps Electric Co., Ltd.
    Inventors: Kiyoshi Sato, Toshinori Watanabe, Toshihiro Kuriyama
  • Publication number: 20030222515
    Abstract: In the stator of a electric rotary machine in which heat conductive insulation resin is filled at the end portions of a stator coil, the material of a stator core, the stator coil, the heat conductive insulation resin and a frame is selected such that a linear thermal expansion coefficient &agr;1 of the stator core, a linear thermal expansion coefficient &agr;2 of the stator coil, a linear thermal expansion coefficient &agr;3 of the heat conductive insulation resin being filled and a linear thermal expansion coefficient &agr;4 of the frame satisfy a relation that &agr;1<&agr;2 <&agr;4 ≦&agr;3. A cooling medium path is integrally formed within the frame made from aluminum through die casting molding.
    Type: Application
    Filed: May 30, 2003
    Publication date: December 4, 2003
    Applicant: HITACHI, LTD.
    Inventors: Toshiaki Ueda, Takeshi Sakai, Susumu Terumoto, Toshinori Watanabe
  • Publication number: 20030193744
    Abstract: A main magnetic pole layer is formed on an insulating layer flattened into a high-flatness surface, and a yoke layer having a large film thickness is formed on the main magnetic pole layer independently of the main magnetic pole. The main magnetic pole layer has a front end surface formed in a shape with a width size gradually increasing in a direction of track width as the front end surface departs farther away from an auxiliary magnetic pole layer. A perpendicular magnetic recording head can be provided which can suppress the occurrence of fringing in a recording pattern, and can form the main magnetic pole layer with high pattern accuracy, and can satisfactorily introduce a recording magnetic field to a fore end of the main magnetic pole layer.
    Type: Application
    Filed: May 9, 2003
    Publication date: October 16, 2003
    Inventors: Toru Takahashi, Hisayuki Yazawa, Hideki Gochou, Kiyoshi Kobayashi, Minoru Yamada, Kiyoshi Sato, Toshinori Watanabe
  • Publication number: 20030087132
    Abstract: By forming a step in a lower core layer, the distance between the upper surface of a Gd-defining layer and the lower core layer is changed stepwise. Consequently, the distance between an upper magnetic pole layer formed on the upper surface of the Gd-defining layer and the lower core layer is small in the front region of the lower core layer, and thus a leakage magnetic field from the upper magnetic pole layer is absorbed by the lower core layer and is not applied to a recording medium.
    Type: Application
    Filed: November 5, 2002
    Publication date: May 8, 2003
    Applicant: Alps Electric Co., Ltd.
    Inventors: Kiyoshi Sato, Toshinori Watanabe, Naruaki Oki
  • Publication number: 20030076630
    Abstract: A thin-film magnetic head has a second lower core layer sandwiched between a magnetic pole laminate, which is formed of a lower magnetic pole layer, a gap layer, and an upper magnetic pole layer laminated in this order from bottom to top, and a first lower core layer. Unlike a conventional thin-film magnetic head, this thin-film magnetic head does not include a gap depth defining layer. This arrangement makes it possible to easily form the magnetic pole laminate into a substantially rectangular shape, and solves the problems with the conventional thin-film magnetic head attributable to the presence of the gap depth defining layer, the problems being typically represented by a curved gap layer or a reduced volume of the upper magnetic pole layer. Thus, the intensity of a recording magnetic field in the vicinity of a gap can be stabilized and increased, allowing the manufacture of thin-film magnetic heads capable of successfully achieving narrower tracks.
    Type: Application
    Filed: October 22, 2002
    Publication date: April 24, 2003
    Applicant: Alps Electric Co., Ltd.
    Inventors: Kiyoshi Sato, Toshinori Watanabe
  • Patent number: 6538845
    Abstract: A high-specific-resistance layer is formed on a soft magnetic layer of an upper core layer in a thin-film magnetic head. The high-specific-resistance layer has a specific resistance which is higher than the specific resistance of the softer magnetic layer. This high-specific-resistance layer can reduce eddy current loss which is generated as the recording frequency increases. The thin-film magnetic head is suitable for high recording frequencies.
    Type: Grant
    Filed: June 27, 2000
    Date of Patent: March 25, 2003
    Assignee: Alps Electric Co., Ltd.
    Inventors: Toshinori Watanabe, Mitsuo Kawasaki