Patents by Inventor Nobumasa Nishiyama

Nobumasa Nishiyama 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: 20130148234
    Abstract: In one embodiment, a hard disk drive includes a magnetic disk medium, a magnetic head adapted for writing data to the magnetic disk medium, a mechanism (such as a detection circuit) adapted for detecting at least one recording condition of drive current provided to the magnetic head during writing operations, and an energy conversion element for controlling at least one recording characteristic of the magnetic head in response to the at least one detected recording condition. According to another embodiment, a method includes writing data to a magnetic medium using a magnetic head, detecting at least one recording condition of drive current provided to the magnetic head during the writing, and controlling at least one recording characteristic of the magnetic head during the writing using an energy conversion element in response to the at least one detected recording condition.
    Type: Application
    Filed: December 12, 2011
    Publication date: June 13, 2013
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Akira Morinaga, Nobumasa Nishiyama, Keiichi Nagasaka
  • Patent number: 8373940
    Abstract: According to one embodiment, a magnetic head for recording magnetic data by changing the magnetization direction of a magnetic recording layer of a magnetic medium comprises a magnetic pole for generating a magnetic field to change the magnetization direction of the magnetic recording layer, and a facing electrode pair for generating an electromagnetic field and applying energy to the magnetic recording layer to assist the change of the magnetization direction of the magnetic recording layer caused by the magnetic field from the magnetic pole. Other embodiments are also presented.
    Type: Grant
    Filed: August 26, 2009
    Date of Patent: February 12, 2013
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Yohji Maruyama, Nobumasa Nishiyama, Masafumi Mochizuki
  • Patent number: 8310789
    Abstract: An integrated conductor/suspension structure for supporting and electrically connecting a write/read head in a hard disk drive and methods of making the conductor/suspension structure are provided. The integrated conductor/suspension structure may allow for an increased characteristic-impedance range, greater interference shielding and a reduction of signal loss that is contributed by a lossy conductive substrate. The suspension structure includes apertures formed therein that result in a reduction in the lossy material and its effect on the electrical signals. In addition, the conductor/suspension structure of the present invention provides shielding to reduce the interference from external electric fields.
    Type: Grant
    Filed: December 22, 2009
    Date of Patent: November 13, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: John T. Contreras, Nobumasa Nishiyama, Xinzhi Xing
  • Patent number: 8248732
    Abstract: A head-gimbal assembly. The head-gimbal assembly includes a suspension, a head-slider coupled to the suspension, a magnetic-recording assistance element on the head-slider for applying an electromagnetic wave to a magnetic-recording disk, and a transmission line on the suspension for transmitting signals to the magnetic-recording assistance element. The transmission line includes an electrically conductive line for transmitting the signals, an upper shield placed above the electrically conductive line along the electrically conductive line, a lower shield placed below the electrically conductive line along the electrically conductive line, and a plurality of columns arranged at each of a right side and a left side of the electrically conductive line along the electrically conductive line for connecting the upper shield and the lower shield. The plurality of columns arranged at the right and left sides includes, respectively, a right linear array of columns and a left linear array of columns.
    Type: Grant
    Filed: September 22, 2009
    Date of Patent: August 21, 2012
    Assignee: Hitachi Global Storage Technologies, Netherlands B.V.
    Inventors: Nobumasa Nishiyama, Yohji Maruyama
  • Publication number: 20120160548
    Abstract: An interleaved conductor structure for electrically connecting the read/write electronics to a read/write head in a hard disk drive is provided. The interleaved conductor structure may allow for an increased characteristic-impedance range, greater interference shielding and a reduction of signal loss that is contributed by a lossy conductive substrate. The electrical traces may have different widths, be offset, or even wrap around each other at the via connections.
    Type: Application
    Filed: December 22, 2010
    Publication date: June 28, 2012
    Inventors: JOHN T. CONTRERAS, Nobumasa Nishiyama, Edgar D. Rothenberg, Rehan A. Zakai, Yiduo Zhang
  • Publication number: 20120162825
    Abstract: An interleaved conductor structure for electrically connecting the read/write electronics to a read/write head in a hard disk drive is provided. The interleaved conductor structure may allow for an increased characteristic-impedance range, greater interference shielding and a reduction of signal loss that is contributed by a lossy conductive substrate. The electrical traces may have different widths, be offset, or even wrap around each other at the via connections.
    Type: Application
    Filed: December 22, 2010
    Publication date: June 28, 2012
    Inventors: JOHN T. CONTRERAS, Nobumasa Nishiyama, Edgar D. Rothenberg, Rehan A. Zakai, Yiduo Zhang
  • Publication number: 20120160538
    Abstract: An interleaved conductor structure for electrically connecting the read/write electronics to a read/write head in a hard disk drive is provided. The interleaved conductor structure may allow for an increased characteristic-impedance range, greater interference shielding and a reduction of signal loss that is contributed by a lossy conductive substrate. The electrical traces may have different widths, be offset, or even wrap around each other at the via connections.
    Type: Application
    Filed: December 22, 2010
    Publication date: June 28, 2012
    Inventors: John T. Contreras, Nobumasa Nishiyama, Edgar D. Rothenberg, Rehan A. Zakai, Yiduo Zhang
  • Publication number: 20120140360
    Abstract: Approaches for integrated lead suspension that provides many benefits, such as enabling a dual stage actuator (DSA) to be used with a single layer flex with a reduced amount of crosstalk. An integrated lead suspension comprises a tail end having a plurality of conductive pads positioned thereat. The plurality of conductive pads includes a first and second dual stage actuator (DSA) pad. The first and second DSA pads are electrically coupled to a conductive member by way of conductive vias. The conductive member may be a stainless steel island. The first DSA pad conducts a signal to a first terminal at each of a plurality of dual stage actuators, while a second terminal at each of the plurality of dual stage actuators is connected to ground.
    Type: Application
    Filed: December 7, 2010
    Publication date: June 7, 2012
    Inventors: John Contreras, Nobumasa Nishiyama, Bijan Rafizadeh, Eiji Soga, Hiroyasu Tsuchida, Yiduo Zhang
  • Patent number: 8194356
    Abstract: A head-stack assembly. The head-stack assembly includes: a magnetic-recording head; a lead-suspension supporting the magnetic-recording head on an actuator arm; a metal plate coupled with the actuator arm; a resin layer disposed on the metal plate; a flexible-printed-circuit board disposed on the resin layer, and substantially perpendicularly connected to the lead-suspension; a arm-electronics module disposed on the flexible-printed-circuit board configured to shape a write-signal current waveform of a write signal to said magnetic-recording head; transmission lines disposed on the flexible-printed-circuit board configured to transmit the write signal to, and a read-back signal from, the lead-suspension; and, a single intermediate conductor layer that is disposed between the resin layer and the flexible-printed-circuit board, and having a planar shape substantially facing a bottom of the arm-electronics module and a bottom of the transmission lines.
    Type: Grant
    Filed: December 22, 2009
    Date of Patent: June 5, 2012
    Assignee: Hitachi Global Storage Technologies, Netherlands B.V.
    Inventors: Kazuhiro Nagaoka, Tatemi Ido, Nobumasa Nishiyama, Yuji Soga
  • Patent number: 8189281
    Abstract: An interconnect between the write driver and the write head in a magnetic recording disk drive enables an inherent write current overshoot. The interconnect includes an integrated lead suspension (ILS) and a short flex cable that connects the write driver circuitry to the ILS. The interconnect is a two-segment transmission line, with the first segment connected to the write driver having multiple sub-segments or sections with non-uniform impedance levels. The section of the first segment that connects to the write driver is the short flex cable and has an impedance substantially higher than the source impedance ZWD of the write driver. The multiple sections of the first segment have non-uniform impedance values that have an effective impedance Z01-eff that substantially matches ZWD. The second segment of the transmission line has an effective impedance Z02-eff that is substantially less than Z01-eff. The write lines for the +W and ?W signals are preferably interleaved on the transmission line sections.
    Type: Grant
    Filed: December 18, 2009
    Date of Patent: May 29, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Michael Alex, John Thomas Contreras, Nobumasa Nishiyama
  • Publication number: 20120033319
    Abstract: A method and apparatus is provided for extending a read bandwidth and increasing a high-frequency signal-to-noise ratio (SNR) of a front-end of a read path of a hard disk drive (HDD) by introducing a high impedance section at the front-end of the read path. The high impedance section may mitigate capacitive effects found at the front-end of the read path, thereby improving signal transfer by extending the read bandwidth.
    Type: Application
    Filed: August 6, 2010
    Publication date: February 9, 2012
    Inventors: John Contreras, Tatemi Ido, Nobumasa Nishiyama, Xinzhi Xing
  • Patent number: 8102628
    Abstract: Embodiments disclose hole sequences that are formed in the metal layer of a trace to adjust rigidity and crosstalk noise resulting from the hole sequences is thereby suppressed. A suspension according to one aspect of the invention includes a trace adapted to transmit a signal of a head slider. The trace partially extends along the side surface of the suspension. The trace includes a metal layer, a plurality of transmission lines formed above the metal layer and an insulating layer. A hole sequence overlapping the transmission lines is formed in part of the metal layer, which contributes to a reduction in transmission loss. Another hole sequence of the metal layer is formed at a position opposed to the hinge portion of the suspension. This reduces the rigidity of the wiring structure portion in the hinge portion, thereby preventing interference with the behavior of the suspension at the hinge portion.
    Type: Grant
    Filed: March 21, 2007
    Date of Patent: January 24, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Ryohei Ota, Eiji Soga, Nobumasa Nishiyama, Hiroyasu Tsuchida
  • Publication number: 20120008237
    Abstract: Approaches for a hard-disk drive suspension interconnect having a wide bandwidth. A suspension interconnect includes a substrate layer, a dielectric layer disposed on the substrate layer, and a plurality of transmission-line (TL) conductors disposed within the dielectric layer. Air gaps may be disposed around the TL conductors to minimize the tendency of the dielectric material to act as an electrical shunt, which impedes high bandwidth signal transmission. An air gap may exist in the dielectric layer between adjacent TL conductors. Additionally, the area adjacent to the plurality of TL conductors, along the direction of signal travel, may alternate between dielectric material and air gaps. Indeed, there need not be any solid material enclosing the TL conductors save for a plurality of dielectric cross ties that provide structural support thereto. The substrate layer may also comprise one or more air gaps underneath a portion of the plurality of TL conductors.
    Type: Application
    Filed: July 8, 2010
    Publication date: January 12, 2012
    Inventors: John Thomas Contreras, Bruce Alvin Gurney, Nobumasa Nishiyama
  • Patent number: 8068313
    Abstract: Embodiments of the present invention relate to approaches to effectively let noise on a head slider bonded to a silicon substrate of a microactuator, escape to the ground. A head gimbal assembly (HGA) according to an embodiment of the present invention comprises a microactuator bonded to a gimbal tongue. The microactuator comprises a piezoelectric element and a movable part for moving in response to expansion or contraction of the piezoelectric element. The motion of the movable part causes a head slider to slightly move. The microactuator further comprises a conductive path including an impurity-containing silicon layer formed on the silicon substrate. The conductive path transmits electric charge of the head slider to a suspension. The conductivity of the impurity-containing silicon layer is lower than the one of the silicon substrate so that the noise charge of the head slider may escape to the suspension.
    Type: Grant
    Filed: November 14, 2008
    Date of Patent: November 29, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Nobumasa Nishiyama, Ryo Yoshida, Haruhide Takahashi, Shinobu Hagiya, Toshiki Hirano
  • Patent number: 7983005
    Abstract: For a Tunneling Magnetoresistive (TMR) element, an electrode is used as a magnetic shield or vice versa. This can pose a problem in that noise from a heater source or electromagnetic induction has a direct influence on the TMR element, namely, on a read signal. According to one embodiment of the present invention, however, a thin film head portion has an insulating film, a heater, an electromagnetic shield, a read element, and a write element laminated in this order from the side of a slider. Insulating films isolate the constituent elements above from each other, and a protection film covers the group mentioned above. The heater is a thin film resistive element made of NiCr or the like, and is disposed above the insulating film. The electromagnetic shield is a magnetic film made of permalloy or the like, and covers the heater. The read element comprises a lower shield and electrode, a TMR element, and an upper shield and electrode.
    Type: Grant
    Filed: April 12, 2007
    Date of Patent: July 19, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands BV
    Inventors: Takayoshi Ohtsu, Nobumasa Nishiyama
  • Patent number: 7969681
    Abstract: Embodiments in accordance with the present invention reduce the structural stress applied to a head, and to achieve the effective control, when the clearance between the head and a disk is adjusted by using a heater. According to one embodiment, the hard disk controller/microprocessing unit (HDC/MPU) controls a slew rate of a heater at the time of TFC (Thermal Fly height Control). In response to processing conditions, a HDC/MPU changes a slew rate of the output of electric current/voltage applied to the heater. This makes it possible to reduce the head stress, and to achieve the effective TFC. To be more specific, with reference to a temperature/slew rate table, the HDC/MPU changes a slew rate in response to the temperature in the read/write processing.
    Type: Grant
    Filed: April 24, 2007
    Date of Patent: June 28, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Noriaki Satoh, Toyomi Ohsawa, Yumi Nagano, Nobumasa Nishiyama
  • Publication number: 20110149442
    Abstract: An integrated conductor/suspension structure for supporting and electrically connecting a write/read head in a hard disk drive and methods of making the conductor/suspension structure are provided. The integrated conductor/suspension structure may allow for an increased characteristic-impedance range, greater interference shielding and a reduction of signal loss that is contributed by a lossy conductive substrate. The suspension structure includes apertures formed therein that result in a reduction in the lossy material and its effect on the electrical signals. In addition, the conductor/suspension structure of the present invention provides shielding to reduce the interference from external electric fields.
    Type: Application
    Filed: December 22, 2009
    Publication date: June 23, 2011
    Inventors: JOHN T. CONTRERAS, Nobumasa Nishiyama, Xinzhi Xing
  • Publication number: 20110149441
    Abstract: An interconnect between the write driver and the write head in a magnetic recording disk drive enables an inherent write current overshoot. The interconnect includes an integrated lead suspension (ILS) and a short flex cable that connects the write driver circuitry to the ILS. The interconnect is a two-segment transmission line, with the first segment connected to the write driver having multiple sub-segments or sections with non-uniform impedance levels. The section of the first segment that connects to the write driver is the short flex cable and has an impedance substantially higher than the source impedance ZWD of the write driver. The multiple sections of the first segment have non-uniform impedance values that have an effective impedance Z01-eff that substantially matches ZWD. The second segment of the transmission line has an effective impedance Z02-eff that is substantially less than Z01-eff. The write lines for the +W and ?W signals are preferably interleaved on the transmission line sections.
    Type: Application
    Filed: December 18, 2009
    Publication date: June 23, 2011
    Applicant: HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B.V.
    Inventors: Michael Alex, John Thomas Contreras, Nobumasa Nishiyama
  • Publication number: 20110102935
    Abstract: A head-stack assembly. The head-stack assembly includes: a magnetic-recording head; a lead-suspension supporting the magnetic-recording head on an actuator arm; a metal plate coupled with the actuator arm; a resin layer disposed on the metal plate; a flexible-printed-circuit board disposed on the resin layer, and substantially perpendicularly connected to the lead-suspension; a arm-electronics module disposed on the flexible-printed-circuit board configured to shape a write-signal current waveform of a write signal to said magnetic-recording head; transmission lines disposed on the flexible-printed-circuit board configured to transmit the write signal to, and a read-back signal from, the lead-suspension; and, a single intermediate conductor layer that is disposed between the resin layer and the flexible-printed-circuit board, and having a planar shape substantially facing a bottom of the arm-electronics module and a bottom of the transmission lines.
    Type: Application
    Filed: December 22, 2009
    Publication date: May 5, 2011
    Inventors: Kazuhiro Nagaoka, Tatemi Ido, Nobumasa NISHIYAMA, Yuji Soga
  • Publication number: 20110090602
    Abstract: A head-gimbal assembly. The head-gimbal assembly includes a suspension, a head-slider coupled to the suspension, a magnetic-recording assistance element on the head-slider for applying an electromagnetic wave to a magnetic-recording disk, and a transmission line on the suspension for transmitting signals to the magnetic-recording assistance element. The transmission line includes an electrically conductive line for transmitting the signals, an upper shield placed above the electrically conductive line along the electrically conductive line, a lower shield placed below the electrically conductive line along the electrically conductive line, and a plurality of columns arranged at each of a right side and a left side of the electrically conductive line along the electrically conductive line for connecting the upper shield and the lower shield. The plurality of columns arranged at the right and left sides includes, respectively, a right linear array of columns and a left linear array of columns.
    Type: Application
    Filed: September 22, 2009
    Publication date: April 21, 2011
    Inventors: Nobumasa NISHIYAMA, Yohji Maruyama