Patents by Inventor Yohji Maruyama

Yohji Maruyama 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: 20060198056
    Abstract: A magnetic head comprises a retrieving unit for converting magnetic information output from a recording medium into an electric signal, a writing unit having the function of electromagnetic conversion for writing the magnetic information in the recording medium in response to the electric signal, and a first protective film formed on the retrieving unit. A second protective film is formed on the first protective film. The coefficient of linear expansion of the second protective film is reduced in comparison with that of the first protective film. Furthermore, the first protective film is an alumina film; in contrast, the second protective film is a film made of an alumina film containing silicon oxide therein.
    Type: Application
    Filed: May 1, 2006
    Publication date: September 7, 2006
    Applicant: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Yohji Maruyama, Tadayuki Iwakura, Takashi Kawabe, Makoto Morijiri, Hiroshi Fukui
  • Publication number: 20060187578
    Abstract: For the purpose of letting through a magnetic flux which reverses the magnetization of the magnetic layer of the magnetic disk, a write element requires a predetermined sectional area. However, if a cross section of a magnetic pole is structured as the one having a large aspect ratio, the pole becomes less capable of letting the magnetic flux through effectively. This phenomenon brings about a lower limit on the track width of the magnetic poles and the track density cannot be raised. In the present invention, by making the width of the write element larger than the track pitch and securing a write magnetic field strong enough to reverse the magnetization of the magnetic layer, and further by writing while shifting a write head comprising the write element, a magnetic disk drive, of which the track width is narrower than the write element width, and the storage capacity is large, is realized.
    Type: Application
    Filed: April 17, 2006
    Publication date: August 24, 2006
    Inventors: Takehiko Hamaguchi, Atsushi Nakamura, Yasutaka Nishida, Hisashi Takano, Yohji Maruyama, Hiroshi Ide, Hideki Sawaguchi, Futoshi Tomiyama
  • Patent number: 7064925
    Abstract: A magnetic head comprises a retrieving unit for converting magnetic information output from a recording medium into an electric signal, a writing unit having the function of electromagnetic conversion for writing the magnetic information in the recording medium in response to the electric signal, and a first protective film formed on the retrieving unit. A second protective film is formed on the first protective film. The coefficient of linear expansion of the second protective film is reduced in comparison with that of the first protective film. Furthermore, the first protective film is an alumina film; in contrast, the second protective film is a film made of an alumina film containing silicon oxide therein.
    Type: Grant
    Filed: September 5, 2003
    Date of Patent: June 20, 2006
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Yohji Maruyama, Tadayuki Iwakura, Takashi Kawabe, Makoto Morijiri, Hiroshi Fukui
  • Patent number: 7057838
    Abstract: In the present invention, by making the width of the write element larger than the track pitch and securing a write magnetic field strong enough to reverse the magnetization of the magnetic layer, and further by writing while shifting a write head comprising the write element, a magnetic disk drive, of which the track width is narrower than the write element width, and the storage capacity is large, is realized.
    Type: Grant
    Filed: April 7, 2003
    Date of Patent: June 6, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Takehiko Hamaguchi, Atsushi Nakamura, Yasutaka Nishida, Hisashi Takano, Yohji Maruyama, Hiroshi Ide, Hideki Sawaguchi, Futoshi Tomiyama
  • Patent number: 7016156
    Abstract: Magnetic disk apparatus includes an electric wiring capable of satisfying an electric condition under which high frequency recording higher than or equal to 200 MHz, a magnetic head having at least a recording device to a magnetic recording medium, and also the electric wiring corresponding to a recording current supplying device to this magnetic head are formed on a suspension member for mechanically suspending the magnetic head, the recording current being supplied to a magnetic head recording device by employing such electric wiring, the characteristic impedance of which is higher than a maximum impedance of the magnetic head recording device.
    Type: Grant
    Filed: October 12, 2004
    Date of Patent: March 21, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Yohji Maruyama, Hiroshi Ikekame, Hisashi Takano
  • Patent number: 6894874
    Abstract: Magnetic disk apparatus includes an electric wiring capable of satisfying an electric condition under which high frequency recording higher than or equal to 200 MHz, a magnetic head having at least a recording device to a magnetic recording medium, and also the electric wiring corresponding to a recording current supplying device to this magnetic head are formed on a suspension member for mechanically suspending the magnetic head, the recording current being supplied to a magnetic head recording device by employing such electric wiring, the characteristic impedance of which is higher than a maximum impedance of the magnetic head recording device.
    Type: Grant
    Filed: July 23, 2003
    Date of Patent: May 17, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Yohji Maruyama, Hiroshi Ikekame, Hisashi Takano
  • Publication number: 20050063097
    Abstract: Magnetic disk apparatus includes an electric wiring capable of satisfying an electric condition under which high frequency recording higher than or equal to 200 MHz, a magnetic head having at least a recording device to a magnetic recording medium, and also the electric wiring corresponding to a recording current supplying device to this magnetic head are formed on a suspension member for mechanically suspending the magnetic head, the recording current being supplied to a magnetic head recording device by employing such electric wiring, the characteristic impedance of which is higher than a maximum impedance of the magnetic head recording device.
    Type: Application
    Filed: October 12, 2004
    Publication date: March 24, 2005
    Inventors: Yohji Maruyama, Hiroshi Ikekame, Hisashi Takano
  • Publication number: 20050007698
    Abstract: A thin film magnetic head and a method of manufacture thereof, wherein the head includes a lower magnetic pole, an upper magnetic pole provided so as to face the lower magnetic pole, and a magnetic gap layer provided between the lower magnetic pole and the upper magnetic pole. The upper magnetic pole is formed by a sputtered first magnetic layer which is an underlayer and a plated second magnetic layer provided on the sputtered first magnetic layer.
    Type: Application
    Filed: August 10, 2004
    Publication date: January 13, 2005
    Inventors: Kazue Kudo, Yasuyuki Okada, Moriaki Fuyama, Yohji Maruyama, Gen Oikawa
  • Publication number: 20040240121
    Abstract: A thin-film magnetic head having little temperature rise in the element, good heat dissipation and a short magnetic path length (narrow coil pitch) and manufacturing method for same is provided. To form the coil of the thin-film magnetic head, a lower coil is first formed and after forming alumina and an inorganic compound containing alumina, a trench is formed for the upper coil by reactive ion etching. The lower coil allows uniform etching at this time and functions as a film to prevent loading effects occurring during reactive ion etching. This trench is then plated in copper and chemical mechanical planarization performed to form the upper layer coil as the dual-layer coil of the present invention. Heat from the coil is efficiently radiated towards the substrate by alumina and an inorganic compound containing alumina with good heat propagation.
    Type: Application
    Filed: August 29, 2003
    Publication date: December 2, 2004
    Inventors: Kimitoshi Etoh, Nobuo Yoshida, Moriaki Fuyama, Makoto Morijiri, Kenichi Meguro, Ichiro Oodake, Kazue Kudo, Yohji Maruyama, Katsuro Watanabe
  • Patent number: 6795272
    Abstract: A thin film magnetic head includes a lower magnetic pole, an upper magnetic pole provided so as to face the lower magnetic pole, and a magnetic gap layer provided between the lower magnetic pole and the upper magnetic pole. The upper magnetic pole constitutes a first magnetic layer formed on a side facing the magnetic gap layer by means of sputtering and a second magnetic layer formed on the first magnetic layer by means of plating, in which the saturation magnetic flux density of the first magnetic layer is set higher than that of the second magnetic layer. The thin film magnetic head composed as above is capable of generating a stronger magnetic field owing to its stably-formed magnetic core, thereby recording on a high-coercivity medium and high-density recording are made possible.
    Type: Grant
    Filed: August 14, 2002
    Date of Patent: September 21, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Kazue Kudo, Yasuyuki Okada, Moriaki Fuyama, Yohji Maruyama, Gen Oikawa
  • Publication number: 20040165310
    Abstract: In a convention inductive head, since a large magnetic field is leaked from the end of the magnetic pole end of an upper magnetic core, at recording the recording magnetic field is applied to a recording media in a region larger than a desired track width, thereby damaging the adjacent information.
    Type: Application
    Filed: March 4, 2004
    Publication date: August 26, 2004
    Inventors: Shunichi Narumi, Hiroyuki Hoshiya, Yohji Maruyama
  • Publication number: 20040125489
    Abstract: Magnetic disk apparatus includes an electric wiringg capable of satisfying an electric condition under which high frequency recording higher than or equal to 200 MHz, a magnetic head having at least a recording device to a magnetic recording medium, and also the electric wiring corresponding to a recording current supplying device to this magnetic head are formed on a suspension member for mechanically suspending the magnetic head, the recording current being supplied to a magnetic head recording device by employing such electric wiring, the characteristic impedance of which is higher than a maximum impedance of the magnetic head recording device.
    Type: Application
    Filed: July 23, 2003
    Publication date: July 1, 2004
    Applicant: Hitachi, Ltd.
    Inventors: Yohji Maruyama, Hiroshi Ikekame, Hisashi Takano
  • Publication number: 20040109262
    Abstract: A magnetic head comprises a retrieving unit 11 for converting magnetic information output from a recording medium into an electric signal, a writing unit 10 having the function of electromagnetic conversion for writing the magnetic information in the recording medium in response to the electric signal, and a first protective film 30 formed on the retrieving unit. A second protective film 31 is formed on the first protective film 30. The coefficient of linear expansion of the second protective film 31 is reduced in comparison with that of the first protective film 30. Furthermore, the first protective film is an alumina film; in contrast, the second protective film is a film made of an alumina film containing silicon oxide therein.
    Type: Application
    Filed: September 5, 2003
    Publication date: June 10, 2004
    Applicant: Hitachi Global Storage Technologies
    Inventors: Yohji Maruyama, Tadayuki Iwakura, Takashi Kawabe, Makoto Morijiri, Hiroshi Fukui
  • Patent number: 6728051
    Abstract: A recording equalizer for correcting a write timing of magnetic information when the magnetic information is recorded with a magnetic recording head on a magnetic recording medium, includes a buffer for storing a recording object bit and bits before and after the recording object bit and a calculator for calculating a precompensation parameter using the bits stored in the buffer. The calculator calculates the preconpensation parameter of the recording object bit by linearly adding influence of a transition existing at a two-previous bit of the recording object bit, influences of a transition at a one-previous bit of the recording object bit and influences of a transition existing at one-following bit of the recording object bit and further adding an offset. The offset is determined to a value such that a write timing of the magnetic information is corrected always in a delaying direction.
    Type: Grant
    Filed: March 17, 2003
    Date of Patent: April 27, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Masukazu Igarashi, Yohji Maruyama, Kazuetsu Yoshida, Ikuo Saitoh
  • Patent number: 6721132
    Abstract: In an inductive head according to the present invention, in order to efficiently carry a magnetic flux to a magnetic pole tip layer, the top surface of the rear end of the magnetic pole tip layer is etched away so as to connect the rear end of the magnetic pole tip layer to the front end of an upper magnetic core having a width larger than that of the rear end of the magnetic pole tip layer. It is possible to realize a recording head having a large recording magnetic field. In addition, the front end of the upper magnetic core is recessed from an air bearing surface by 0.2 to 3.0 &mgr;m so as to reduce the magnetic field leaked from the end of the upper magnetic core.
    Type: Grant
    Filed: March 20, 2001
    Date of Patent: April 13, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Shunichi Narumi, Hiroyuki Hoshiya, Yohji Maruyama
  • Patent number: 6683823
    Abstract: A method for reproducing information on a recording medium includes irradiating electromagnetic energy or light to the recording medium from one side with respect to the recording medium, applying a recording magnetic field to an electromagnetic energy or light irradiated position on the recording medium from the one side of irradiating electromagnetic energy or light, and detecting magnetic leakage flux emerging from the recording medium from the one side of irradiating electromagnetic energy or light.
    Type: Grant
    Filed: December 17, 2002
    Date of Patent: January 27, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Hideki Saga, Hiroaki Nemoto, Hirofumi Sukeda, Masahiko Takahashi, Kimio Nakamura, Yohji Maruyama, Hiroshi Ide, Takehiko Hamaguchi
  • Patent number: 6661613
    Abstract: Magnetic disk apparatus includes an electric wiring capable of satisfying an electric condition under which high frequency recording higher than or equal to 200 MHz, a magnetic head having at least a recording device to a magnetic recording medium, and also the electric wiring corresponding to a recording current supplying device to this magnetic head are formed on a suspension member for mechanically suspending the magnetic head, the recording current being supplied to a magnetic head recording device by employing such electric wiring, the characteristic impedance of which is higher than a maximum impedance of the magnetic head recording device.
    Type: Grant
    Filed: December 13, 2002
    Date of Patent: December 9, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Yohji Maruyama, Hiroshi Ikekame, Hisashi Takano
  • Publication number: 20030189774
    Abstract: For the purpose of letting through a magnetic flux which reverses the magnetization of the magnetic layer of the magnetic disk, a write element requires a predetermined sectional area. However, if a cross section of a magnetic pole is structured as the one having a large aspect ratio, the pole becomes less capable of letting the magnetic flux through effectively. This phenomenon brings about a lower limit on the track width of the magnetic poles and the track density cannot be raised. In the present invention, by making the width of the write element larger than the track pitch and securing a write magnetic field strong enough to reverse the magnetization of the magnetic layer, and further by writing while shifting a write head comprising the write element, a magnetic disk drive, of which the track width is narrower than the write element width, and the storage capacity is large, is realized.
    Type: Application
    Filed: April 7, 2003
    Publication date: October 9, 2003
    Inventors: Takehiko Hamaguchi, Atsushi Nakamura, Yasutaka Nishida, Hisashi Takano, Yohji Maruyama, Hiroshi Ide, Hideki Sawaguchi, Futoshi Tomiyama
  • Publication number: 20030142430
    Abstract: A recording equalizer for correcting a write timing of magnetic information when the magnetic information is recorded with a magnetic recording head on a magnetic recording medium, includes a buffer for storing a recording object bit and bits before and after the recording object bit and a calculator for calculating a precompensation parameter using the bits stored in the buffer. The calculator calculates the preconpensation parameter of the recording object bit by linearly adding influence of a transition existing at a two-previous bit of the recording object bit, influences of a transition at a one-previous bit of the recording object bit and influences of a transition existing at one-following bit of the recording object bit and further adding an offset. The offset is determined to a value such that a write timing of the magnetic information is corrected always in a delaying direction.
    Type: Application
    Filed: March 17, 2003
    Publication date: July 31, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Masukazu Igarashi, Yohji Maruyama, Kazuetsu Yoshida, Ikuo Saitoh
  • Publication number: 20030123333
    Abstract: A method for reproducing information on a recording medium includes irradiating electromagnetic energy or light to the recording medium from one side with respect to the recording medium, applying a recording magnetic field to an electromagnetic energy or light irradiated position on the recording medium from the one side of irradiating electromagnetic energy or light, and detecting magnetic leakage flux emerging from the recording medium from the one side of irradiating electromagnetic energy or light.
    Type: Application
    Filed: December 17, 2002
    Publication date: July 3, 2003
    Inventors: Hideki Saga, Hiroaki Nemoto, Hirofumi Sukeda, Masahiko Takahashi, Kimio Nakamura, Yohji Maruyama, Hiroshi Ide, Takehiko Hamaguchi