Patents by Inventor Hidekazu Kohira

Hidekazu Kohira 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: 7542238
    Abstract: Embodiments of the invention prevent the reduction of the flying height of a magnetic head slider at a high altitude and thereby to improve the reliability of a magnetic disk drive. In one embodiment, a magnetic head slider has an air inlet end, an air outlet end, and an aerodynamic structure (air bearing surface). The aerodynamic structure includes: a plurality of inlet rails respectively having inlet rail surfaces; an outlet rail having an outlet rail surface flush with the inlet rail surfaces and holding a magnetic head; a bearing surface extending at a predetermined first depth ?1 from a reference plane including the inlet and the outlet rail surfaces; a negative-pressure surface extending in a plane at a predetermined second depth ?2 greater than the first depth ?1 from the reference plane; and longitudinal lands of a predetermined height h formed on the inlet rails. The bearing surface and the inlet rail surfaces extend between the air inlet end and the lands.
    Type: Grant
    Filed: April 12, 2005
    Date of Patent: June 2, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hidekazu Kohira
  • Patent number: 7525765
    Abstract: In a magnetic disk apparatus, mounting of plural heating elements to a magnetic head slider is permitted. Thermally assisted magnetic recording from inner to outer surface is permitted at a small amount of power consumption. In one embodiment, the magnetic disk apparatus has a magnetic disk on which magnetic information is recorded, a magnetic head slider having an air bearing surface for floating from the magnetic disk in proximity thereto, and a rotary actuator moving over the disk arcuately while supporting the magnetic head slider by a suspension. A recording element acting to record magnetic information on the magnetic disk, a playback element acting to play back the magnetic information recorded on the magnetic disk, and plural heating elements acting to locally heat the magnetic disk are carried on the magnetic head slider.
    Type: Grant
    Filed: December 8, 2005
    Date of Patent: April 28, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Masayuki Kurita, Takehiko Hamaguchi, Hidekazu Kohira, Mikio Tokuyama
  • Publication number: 20080204936
    Abstract: A head slider for a magnetic disk drive is provided. The head slider includes a leading edge, a trailing edge, an inner diameter side and an outer diameter side of an air bearing surface. The head slider further includes a first recess on the air bearing surface of the head slider, the first recess defining a first rail proximate the inner diameter side and a second rail proximate the outer diameter side wherein the first rail and the second rail are higher with respect to the recess and are asymmetrical with respect to each other.
    Type: Application
    Filed: February 28, 2007
    Publication date: August 28, 2008
    Inventors: Weidong Huang, Hidekazu Kohira, Yoshinori Takeuchi
  • Publication number: 20080192379
    Abstract: Embodiments of the present invention provide a process that monitors a magnetic playback signal while gradually increasing an electricity supply amount for a heater to thereby determine contact between a magnetic head slider and a magnetic disk medium. According to one embodiment, after components for configuring a magnetic recording/playback portion are assembled into a housing, magnetic information is played back on a specific track of a magnetic disk medium by using a playback element while gradually increasing an electricity supply amount for a heater of a magnetic head slider. An amplitude of a playback signal is measured at a plurality of portions along a circumferential direction of the track. Contact between the magnetic head slider and the magnetic disk medium is detected in accordance with an increase in variation in the measured amplitude.
    Type: Application
    Filed: January 24, 2008
    Publication date: August 14, 2008
    Inventors: Masayuki Kurita, Hideaki Tanaka, Noriaki Satoh, Toyomi Ohsawa, Toshiya Shiramatsu, Atsushi Yatagai, Satoshi Ohki, Hiroshi Ide, Hidekazu Kohira, Takehiko Hamaguchi
  • Publication number: 20080170332
    Abstract: Embodiments of the present invention provide a slider that may suppress contamination from being attached to the flying surface of the slider without influence on reduction of the flying height of the slider, and a method for producing the same. According to one embodiment, ions exerting an effect of decreasing surface energy are implanted in the whole surface of a flying surface of a magnetic head slider except for a front rail surface and a center rail surface. According to this, contamination is prevented from being attached to a front step bearing surface, a side step bearing surface, a center step bearing surface and a negative pressure groove where contamination is particularly liable to be attached in the flying surface of the magnetic head slider, so as to suppress destabilization in flying of the slider.
    Type: Application
    Filed: September 7, 2007
    Publication date: July 17, 2008
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Yuki Shimizu, Junguo Xu, Jianhua Li, Hidekazu Kohira, Tetsuya Matsusaki, Hidetoshi Anan
  • Publication number: 20080158724
    Abstract: A head slider for a magnetic disk drive is provided. The head slider includes a leading edge, a trailing edge, an inner diameter side and an outer diameter side of an air bearing surface. The head slider further includes a first recess on the air bearing surface of the head slider, a second recess on the air bearing surface of the head slider wherein the second recess is deeper than the first recess and a third recess on the air bearing surface of the head slider wherein the third recess is deeper than the second recess and is disposed within the second recess, forming a first pocket.
    Type: Application
    Filed: December 28, 2006
    Publication date: July 3, 2008
    Inventors: Lee K. Dorius, Hidekazu Kohira, Jianhua Li, Satoru Ookubo
  • Patent number: 7362544
    Abstract: A thermal flying height adjustment slider capable of being mounted on a small-sized thin film magnetic head slider is provided wherein terminals of an energizer serving as a heater prevent corrosion of pole pieces and the number of terminals is reduced. In one embodiment, one of terminals of the energizer serving as the heater is electrically connected to the lower pole piece, so that a relay terminal for a heating device is used also as the terminal for preventing the corrosion of pole pieces.
    Type: Grant
    Filed: September 17, 2004
    Date of Patent: April 22, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Toshiya Shiramatsu, Masayuki Kurita, Mikio Tokuyama, Hidekazu Kohira, Masahiko Soga
  • Publication number: 20080024915
    Abstract: Embodiments of the present invention provide a magnetic head and a magnetic disk drive using the same, which is capable of increasing efficiency in changing the flying height of an element portion by heat generation of a heater in the magnetic head using the heater as well as capable of suppressing the change of the flying height of the element portion at the time of recording. In a magnetic head according to one embodiment of the invention, when a portion is defined as a “heater immobility line”, in which a position of the positive pressure generation surface does not vary when the electricity is distributed to a heater, and a portion is defined as a “write immobility line”, in which a position of the positive pressure generation surface does not vary at the time of recording, the area of the raised region surrounded by the heater immobility line is smaller than the area of the raised region surrounded by the write immobility line.
    Type: Application
    Filed: July 19, 2007
    Publication date: January 31, 2008
    Applicant: Hitachi Global Storage Technologies Netherlands B. V.
    Inventors: Koji Miyake, Hidekazu Kohira, Kiyoshi Hashimoto, Takanori Yamazaki, Hideaki Tanaka
  • Publication number: 20070253111
    Abstract: Embodiments in accordance with the present invention provide a magnetic head slider capable of securing a larger flying margin even when position variations occur at the time of flying. Embodiments of the present invention also provide a magnetic head slider having an excellent flying following capability. A read element and a write element of a magnetic head slider are arranged on a spherical or ellipsoidal projection and this projection is formed on a thin film magnetic head part. This may prevent a flying margin from being reduced by variations in flying position and may prevent a manufacturing step from being caused on the spherical or ellipsoidal projection. Moreover, by making the constituent ratio of the thin film magnetic head part on an air-bearing surface of the magnetic head slider 100 to be 7% or more, the read element and the write element are arranged at a pressure center position on the center rail surface of the air-bearing surface.
    Type: Application
    Filed: March 23, 2007
    Publication date: November 1, 2007
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Yuki Shimizu, Junguo Xu, Hidekazu Kohira
  • Publication number: 20070058296
    Abstract: Embodiments of the invention provide a slider structure able to lower a flying height compensation ratio caused by a projecting deformation of an air bearing surface of a slider by a flying height control mechanism and afford a change in flying height with a low control power. In one embodiment, a slider is provided with a leading edge, an air bearing surface, and a trailing edge. The air bearing surface includes a front pad, the front pad being made up of a front step bearing surface, leading rail surfaces, and side step bearing surfaces. The air bearing surface also includes a negative pressure groove surface surrounded by the front pad.
    Type: Application
    Filed: September 6, 2006
    Publication date: March 15, 2007
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Kiyoshi Hashimoto, Hidekazu Kohira, Takanori Yamazaki, Koji Miyake
  • Publication number: 20070025023
    Abstract: Embodiments of the invention provide Femto and below form factor magnetic head slider designs both capable of minimizing reduction of its flying height at high altitude and lower flying height sensitivity on manufacturing process tolerance. In one embodiment, the air bearing surface of a magnetic head slider includes a plurality of inlet rails respectively having inlet rail surfaces, a step bearing surface extending at a predetermined first depth from a reference plane including the inlet and the outlet rail surfaces, a negative surface extending in a plane at a predetermined second depth greater than the first depth from the reference plane, longitudinal carbon islands of a predetermined height formed on the inlet rails, and an outlet rail having an outlet rail surface flush with the inlet rail surfaces and holding a magnetic R/W head. The step bearing surface extends at a predetermined first depth from a reference plane.
    Type: Application
    Filed: July 26, 2005
    Publication date: February 1, 2007
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hidekazu Kohira, Jianhua Li, Junguo Xu
  • Patent number: 7164556
    Abstract: A magnetic head slider includes a magnetic head mounting surface, a slider rail surface, a step air bearing surface, and a negative pressure groove. The magnetic head mounting surface is arranged in a center area with respect to a width of the slider near an air flow-out edge on the slider and mounts a magnetic head. The slider rail surface has a first depth from the magnetic head mounting surface and its width on an air flow-in side for the magnetic head is wider that its width on an air flow-out side for the magnetic head. The step air bearing surface is formed on an air flow-in side of the slider rail surface and has a second depth from the slider rail surface. The negative-pressure groove which formed on an air flow-in side of the step air bearing surface and has a third depth from the step air bearing surface.
    Type: Grant
    Filed: August 11, 2005
    Date of Patent: January 16, 2007
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Hidekazu Kohira, Masaaki Matsumoto, Hideaki Tanaka, Teruyoshi Higashiya, Kiyoshi Hashimoto, Akira Matsuda, Takanori Yamazaki
  • Patent number: 7095587
    Abstract: In a slider using thermal expansion type, being adjustable on a flying height thereof, having problems to be solved, i.e., to reduce the electric power consumption, and to lesson the heat load upon a reproducing element thereof, wherein a heating device 4 is located separating from tip portions of the recording and reproducing elements 2 and 3. Also, for deforming only the vicinity of the heating device 4 and the recording and reproducing elements 2 and 3, so as to protrude from, the heating device 4 and the recording and reproducing elements 2 and 3 are surrounded by a resin film 6 of small rigidity, thereby increasing an amount of protrusion of the recording and reproducing elements 2 and 3 per a unit of electric power, but without increasing temperature of the reproducing element 3, with an aim of the structure of cutting off the force from materials of circumferences against the deformation.
    Type: Grant
    Filed: September 11, 2003
    Date of Patent: August 22, 2006
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Masayuki Kurita, Toshiya Shiramatsu, Hideaki Tanaka, Sunao Yonekawa, Koji Miyake, Hidekazu Kohira, Mikio Tokuyama
  • Patent number: 7085103
    Abstract: A magnetic head slider, for sliding on a magnetic disk, which has a leading edge, a trailing edge, an air bearing surface having a front step bearing of submicron depth made from the leading edge, and a rail surface made from the front step bearing. A negative pressure recess which is deeper than the front step bearing, is formed as a recess from the rail surf ace, and a side step bearing with a depth identical to that of the front step bearing is made from the rail surface. Side padB are provided which each have a width W and length L, wherein W is greater than L.
    Type: Grant
    Filed: December 14, 2004
    Date of Patent: August 1, 2006
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Hidekazu Kohira, Masaaki Matsumoto, Kiyoshi Hashimoto, Masayoshi Endo, Akio Takakura, Yoshinori Takeuchi, Shinsuke Higuchi, Akira Iida
  • Publication number: 20060139810
    Abstract: Embodiments of the invention reduce damage to a disk recording medium when a slider flying above the disk recording medium inside a magnetic disk drive comes into contact with the disk recording medium due to slider vibration. In one embodiment, a magnetic head slider includes a front pad, a rear pad, and carbon protective films. The front pad includes a step bearing surface disposed on the side of a leading end and leading side rail surfaces formed on the step bearing surface. The rear pad includes a rear step bearing surface disposed across a deep groove surface from the front pad and a trailing side rail surface formed on the rear step bearing surface. The carbon protective films are formed on regions including vertices of slider corner portions, respectively. The leading side rail surfaces and the trailing side rail surface are formed substantially on the same level. The carbon protective films are harder than a slider base material and have a small coefficient of friction.
    Type: Application
    Filed: December 22, 2005
    Publication date: June 29, 2006
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Kiyoshi Hashimoto, Hidekazu Kohira, Takanori Yamazaki, Koji Miyake
  • Patent number: 7061722
    Abstract: A magnetic disk unit includes a magnetic disk attached to a spindle so as to be rotatable, a slider having a magnetic head for reading/writing data onto/from the magnetic disk, a suspension for providing the slider with a predetermined load, and an actuator arm for positioning the slider attached to the suspension on the magnetic disk. A first pad including the magnetic head and second pads including no magnetic heads are disposed on an air bearing surface of the slider. During rotation of said magnetic disk, a part of the first pad keeps in contact with the magnetic disk. A load point of the suspension with respect to the slider is positioned between a leading edge of the slider and a position located at a distance equivalent to substantially 0.42 times a whole length of the slider from the leading edge of the slider.
    Type: Grant
    Filed: September 18, 2002
    Date of Patent: June 13, 2006
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Hidekazu Kohira, Hiromitsu Tokisue, Masaaki Matsumoto, Masayuki Suzuki, Yoshinori Takeuchi, Toshihiko Shimizu
  • Publication number: 20060119971
    Abstract: In a magnetic disk apparatus, mounting of plural heating elements to a magnetic head slider is permitted. Thermally assisted magnetic recording from inner to outer surface is permitted at a small amount of power consumption. In one embodiment, the magnetic disk apparatus has a magnetic disk on which magnetic information is recorded, a magnetic head slider having an air bearing surface for floating from the magnetic disk in proximity thereto, and a rotary actuator moving over the disk arcuately while supporting the magnetic head slider by a suspension. A recording element acting to record magnetic information on the magnetic disk, a playback element acting to play back the magnetic information recorded on the magnetic disk, and plural heating elements acting to locally heat the magnetic disk are carried on the magnetic head slider.
    Type: Application
    Filed: December 8, 2005
    Publication date: June 8, 2006
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Masayuki Kurita, Takehiko Hamaguchi, Hidekazu Kohira, Mikio Tokuyama
  • Publication number: 20060119986
    Abstract: A compact slider has a reduced area of bearing surfaces, thus substantially decreasing a lifting force obtained through an air bearing characteristic. In one embodiment, a shallowly grooved surface and air bearing surfaces are disposed on an inflow side of a bearing surface of a slider. The air bearing surfaces are connected to each other through a connection air bearing surface. Side shallowly grooved surfaces are respectively disposed rearward of the air bearing surfaces. The side shallowly grooved surface extends up to a point near an outflow end. A center air bearing surface is disposed on the outflow end of the slider. A magnetic head is mounted on the center air bearing surface. A center shallowly grooved surface is disposed on an inflow side of the center air bearing surface. A deeply grooved surface is disposed at a center of the bearing surface. No cutting margins are provided on both sides of the slider.
    Type: Application
    Filed: November 17, 2005
    Publication date: June 8, 2006
    Applicant: Hitachi Global Storage Technologies Netherlands B.V
    Inventors: Yoshinori Takeuchi, Hidekazu Kohira
  • Publication number: 20060114612
    Abstract: A compact slider has a reduced area of bearing surfaces, thus remarkably decreasing a lifting force obtained by an air bearing characteristic. In one embodiment, a shallowly grooved surface is disposed on an inflow side of a bearing surface of a slider, and a pair of inflow side air bearing surfaces are disposed rearward of and adjacently to the shallowly grooved surface. Side shallowly grooved surfaces are disposed on both sides rearward of the air bearing surfaces in such a manner as to extend near an outflow end. A center air bearing surface is disposed at a center in a width direction at the outflow end of the slider. A magnetic head is mounted at the center air bearing surface. A center shallowly grooved surface is disposed on an inflow side of the center air bearing surface. A deeply grooved surface is disposed at a center of the bearing surface surrounded substantially by the air bearing surfaces, the side shallowly grooved surface, and the center shallowly grooved surface.
    Type: Application
    Filed: November 16, 2005
    Publication date: June 1, 2006
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Yoshinori Takeuchi, Hidekazu Kohira
  • Patent number: 7042678
    Abstract: A magnetic head slider in which a leading pad is projected in a thicknesswise direction of the slider, in comparison with a trailing pad so as to reduce vibration caused by contact between a flat medium surface of a disc and the slider carrying thereon a magnetic head, to reduce variation in flying height caused by wavy unevenness of the medium surface, and to reduce variation in atmospheric pressure around the slider, thereby it is possible to enhance the recording density and the reliability of the magnetic head slider while reducing the costs thereof. Further, a magnetic disc unit using the above-mentioned magnetic head slider.
    Type: Grant
    Filed: June 25, 2003
    Date of Patent: May 9, 2006
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Ryuji Tsuchiyama, Hiroshi Tani, Mikio Tokuyama, Hidekazu Kohira, Masayuki Kurita, Mitsuhiro Shoda, Junguo Xu, Masaaki Matsumoto