Patents by Inventor Masafumi Mochizuki

Masafumi Mochizuki 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: 7606006
    Abstract: Embodiments of the invention provide a write head for perpendicular recording in which the magnetic field intensity applied at a read element is reduced with larger write-field gradients and the distance between a write element and a read element is small. In one embodiment, a pair of magnetic bodies for shielding a read element are provided on the leading and trailing sides of the read element respectively and whichever one of the two shields is the longer in the length from the air bearing surface is shorter than the length up to the back contact position PBK at which a main pole and an auxiliary pole are connected.
    Type: Grant
    Filed: December 15, 2004
    Date of Patent: October 20, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Masafumi Mochizuki, Kaori Suzuki, Kimitoshi Etoh
  • Publication number: 20090168241
    Abstract: Embodiments of the present invention help to inhibit record information in a perpendicular magnetic recording disk drive from being attenuated or erased due to leakage of a recording magnetic field into the already-recorded information. According to one embodiment, a magnetic disk includes a soft magnetic underlayer and a magnetic recording layer. A magnetic head includes a main magnetic pole, an auxiliary magnetic pole, a trailing shield which is disposed via a non-magnetic film on a trailing side of the main magnetic pole and in which a reverse side is in contact with the auxiliary magnetic pole, and side shields disposed on both sides of the main magnetic pole.
    Type: Application
    Filed: December 4, 2008
    Publication date: July 2, 2009
    Inventors: Masafumi Mochizuki, Hideaki Maeda, Shuji Nishida, Takaaki Izumida
  • Publication number: 20090161263
    Abstract: Embodiments of the present invention provide a magnetic head for perpendicular magnetic recording, and a magnetic disk apparatus capable of preventing data erasure caused by alignment marks. In an embodiment, the magnetic head includes a head element including at least a main pole having a pole face on a flying surface and an auxiliary pole; alignment marks made of a magnetic material and used to detect the amount of lapping work when lapping the pole face of the main pole; and members made of a magnetic material, continuously extending in either direction with respect to the position of the main pole from within the alignment marks outward at least beyond the alignment marks.
    Type: Application
    Filed: December 3, 2008
    Publication date: June 25, 2009
    Inventors: Mao Nishiyama, Shuji Nishida, Hideaki Maeda, Masafumi Mochizuki
  • Publication number: 20090154012
    Abstract: Embodiments of the invention reduce generation of a magnetic field with a polarity reverse to that of the recording magnetic field, without deteriorating a gradient in the magnetic field. An embodiment of a magnetic disk device according to the present invention suppresses deviation and erase of already recorded data. In an embodiment, the perpendicular magnetic recording head includes the main magnetic pole, an auxiliary magnetic pole, a trailing shield disposed on the trailing side of the main magnetic pole with a non-magnetic film placed in-between, and side shields disposed on both the sides of the main magnetic pole in the direction of the track width with a non-magnetic film placed in-between. The trailing shield has on the trailing side a portion where film thickness is thinner on the trailing side than the thickness of its element in the height direction in its position facing the main magnetic pole.
    Type: Application
    Filed: November 19, 2008
    Publication date: June 18, 2009
    Inventors: Masafumi Mochizuki, Hideaki Maeda, Shuji Nishida, Takaaki Izumida
  • Patent number: 7545595
    Abstract: A magnetic disk apparatus including: a disk holding data as magnetic information on a magnetic recording film; a head to perform writing and reading of the magnetic information; a rotary actuator to move the head in a radial direction of the disk; plural heat elements in the head to locally heat the disk; a write element in the head to apply a magnetic field to the disk; and means for selecting at least one heat element from the plural heat elements, wherein the means for selecting the heat element selects at least one heat element from the plural heat elements so as to bring a center line of an area heated by the heat element and a center line of the position of the magnetic field generated by the write element into approximate correspondence, in correspondence with a relative angle between the head and a direction of movement of the disk.
    Type: Grant
    Filed: February 16, 2006
    Date of Patent: June 9, 2009
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Takehiko Hamaguchi, Atsushi Nakamura, Yasutaka Nishida, Masafumi Mochizuki, Hideki Sawaguchi
  • Patent number: 7542244
    Abstract: Embodiments of the invention provide a magnetic head (magnetic disk storage) which does not erase data on a recording medium even when a stray field is applied. In one embodiment, the head has a structure that d1<t1 and d2<t2 are satisfied where d1denotes the positional difference between edges of an auxiliary pole and an upper shield in the cross-track direction, d2 denotes the positional difference between edges of the upper shield and a lower shield in the cross-track direction, t1 the film thickness of the auxiliary pole or upper shield, whichever magnetic layer is larger in cross-track width, and t2 the film thickness of the upper shield or lower shield, whichever magnetic layer is larger in cross-track width.
    Type: Grant
    Filed: October 17, 2005
    Date of Patent: June 2, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hiroshi Fukui, Yoji Maruyama, Masafumi Mochizuki, Tomohiro Okada
  • Patent number: 7532433
    Abstract: Thin film perpendicular magnetic head with a narrow main pole capable of a high recording density in excess of 100 gigabits per square inch and generating a high magnetic recording field, while also being modified to suppress remanent magnetic fields occurring immediately after writing operation. A return path is provided for supplying a magnetic flux to the main pole, and an conductive coil for excitation of the main pole and return path. The main pole has a pole width of 200 nanometers or less, and a magnetic multilayer made up of a high saturation flux density layer and low saturation flux density layer. The low saturation flux density layer and the high saturation flux density suppress remanent magnetization and prevent erasing after writing by utilizing a closed magnetic domain structure in the pole.
    Type: Grant
    Filed: May 22, 2007
    Date of Patent: May 12, 2009
    Assignee: Hitachi Global Storage Technologies Japa
    Inventors: Yoshiaki Kawato, Kazuhiro Nakamoto, Hiroyuki Hoshiya, Yasuyuki Okada, Masafumi Mochizuki
  • Publication number: 20090059425
    Abstract: Thin film perpendicular magnetic head with a narrow main pole capable of a high recording density in excess of 100 gigabits per square inch and generating a high magnetic recording field, while also being modified to suppress remanent magnetic fields occurring immediately after writing operation. A return path is provided for supplying a magnetic flux to the main pole, and an conductive coil for excitation of the main pole and return path. The main pole has a pole width of 200 nanometers or less, and a magnetic multilayer made up of a high saturation flux density layer and low saturation flux density layer. The low saturation flux density layer and the high saturation flux density suppress remanent magnetization and prevent erasing after writing by utilizing a closed magnetic domain structure in the pole.
    Type: Application
    Filed: October 21, 2008
    Publication date: March 5, 2009
    Inventors: Yoshiaki Kawato, Kazuhiro Nakamoto, Hiroyuki Hoshiya, Yasuyuki Okada, Masafumi Mochizuki
  • Patent number: 7483243
    Abstract: Embodiments of the invention provide a magnetic head which prevents data on a recording medium from being erased even when a stray field is applied. In one embodiment, a magnetic head includes a perpendicular write head having a main pole and an auxiliary pole; and a read head having a lower shield, an upper shield and a magneto-resistive element formed between the lower shield and the upper shield. At least one of the auxiliary pole, lower shield and upper shield has a recessed portion, whose height in an element height direction is lower than the height of edges thereof in a track width direction, on a surface opposite to the air bearing surface.
    Type: Grant
    Filed: October 17, 2005
    Date of Patent: January 27, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hiroshi Fukui, Yoji Maruyama, Masafumi Mochizuki, Kaori Suzuki
  • Patent number: 7475470
    Abstract: On the trailing side of a main pole air bearing surface of a magnetic head for perpendicular recording, the central portion is formed closer to the leading side than the corners on the trailing side, such that the main pole air bearing surface is formed in the shape of a recess with respect to the tailing side. As a result, it is possible to linearize the magnetic field distribution on the trailing side whereby the magnetic reversal is determined, and to record a bit without curving the shape of magnetic reversal.
    Type: Grant
    Filed: February 10, 2004
    Date of Patent: January 13, 2009
    Assignee: Hitachi Global Storage Technologies, LTD.
    Inventors: Masafumi Mochizuki, Tomohiro Okada, Atsushi Nakamura
  • Patent number: 7450349
    Abstract: Embodiments of the invention avoid erasure of recorded data by concentrating stray fields on a magnetic head element. According to one embodiment, in a magnetic storage apparatus using a perpendicular recording medium with a soft magnetic under layer, a soft magnetic shield is provided so as to surround the upper parts and sides of magnetic head elements. A distance between the soft magnetic shield and the medium is shorter than that between the soft magnetic shield and the magnetic head element.
    Type: Grant
    Filed: December 2, 2005
    Date of Patent: November 11, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Yasutaka Nishida, Ikuya Tagawa, Masafumi Mochizuki, Roger Wood
  • Patent number: 7426092
    Abstract: Embodiments of the invention provide a magnetic head which prevents data on a recording medium from being erased even when a stray field is applied. In one embodiment, an auxiliary pole is sandwiched between a stray-field shield composed of a magnetic layer recessed from the air bearing surface and a main pole. The stray-field shield may be formed on the leading side of the auxiliary pole. A face of the stray-field shield on a medium side may be recessed from an air-bearing-surface of the magnetic head.
    Type: Grant
    Filed: June 30, 2005
    Date of Patent: September 16, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hiroshi Fukui, Masafumi Mochizuki, Kaori Suzuki
  • Publication number: 20080180839
    Abstract: In a patterned perpendicular magnetic recording medium, embodiments of the present invention provide a magnetic head in which magnetic field to be applied to adjacent tracks can be suppressed and a recording device equipped with the magnetic head. In one embodiment of the present invention, a sum of a width Pw of a main pole of a magnetic head and distances between right and left magnetic substances on a width-directional side of tracks and the main pole, so-called widths of side gap lengths s_g1—1 and s_g1—2 is, in a magnetic recording medium having a soft-magnetic underlayer, made to be not more than a sum of a width w_land of a convexity or land of the soft-magnetic underlayer and widths w_groove—1 and w_groove—2 of concavities or grooves adjacent to the land on both its sides.
    Type: Application
    Filed: January 9, 2008
    Publication date: July 31, 2008
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Masafumi Mochizuki, Yukiya Shimizu, Shuji Nishida
  • Patent number: 7370405
    Abstract: A thin film magnetic head for perpendicular recording of a single-pole type has a flux enhanced part and a flux enhanced end arranged on a leading side of the main pole in parallel with the cross track direction. The side surface of the main pole intersecting the cross track direction is arranged on the track center side perpendicular to the track width. The field gradient of a perpendicular magnetic field on the trailing side of the main pole and near both ends of the track is made steep to realize a higher areal recording density. The head is fabricated by forming a first resist pattern on an inorganic insulating layer. A slope is formed on the inorganic insulating layer with the resist pattern as a mask. A second resist pattern is then formed on the inorganic insulating layer to form a magnetic layer on the inorganic insulating layer.
    Type: Grant
    Filed: March 15, 2005
    Date of Patent: May 13, 2008
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Atsuko Kuroda, Masafumi Mochizuki
  • Publication number: 20080007868
    Abstract: Embodiments of the present invention provide a perpendicular magnetic recording medium capable of suppressing a magnetic field intensity applied to adjacent tracks on a patterned perpendicular recording medium. According to one embodiment of the present invention, unevenly formed soft under layers are stacked on a flat nonmagnetic substrate, thereby the saturation magnetic flux density of the protruded region is set lower than that of the flat region.
    Type: Application
    Filed: July 3, 2007
    Publication date: January 10, 2008
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Yasutaka Nishida, Masafumi Mochizuki
  • Publication number: 20070297097
    Abstract: Embodiments in accordance with the present invention provide a magnetic head of the CPP structure for perpendicular magnetic recording, that is excellent in read performance, and stable in write/read performances by enhancing the external field durability, and further, suppresses deterioration in read sensor property, due to thermal factors. At least either shield layer of a lower magnetic shield layer, and an upper magnetic shield layer, closer to a perpendicular magnetic write head, is made up so as to have a multi-layered structure comprising low thermal expansion nonmagnetic layers, and magnetic layers. Material having a coefficient of thermal expansion smaller than that of a magnetoresistive film is selected as a material for the low thermal expansion nonmagnetic layers of the shield layer.
    Type: Application
    Filed: May 29, 2007
    Publication date: December 27, 2007
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Katsuro Watanabe, Katsumi Hoshino, Masafumi Mochizuki
  • Publication number: 20070253107
    Abstract: Embodiments in accordance with the present invention provide a perpendicular recording magnetic head whose dimensional dependency on the nonuniformity of magnetic field strength and distribution during manufacture is minimized, with narrowed tracks and without attenuation or erasure of adjacent track data while maintaining high magnetic field strength. According to one embodiment, a magnetic material (trailing/side shield) for creating a steep gradient of magnetic field strength is provided at a trailing side of a pole tip of a main magnetic pole piece and in a direction of the track width. The magnetic head is formed so that a gap (side gap length “gl”) between a side shield and a throat height portion of the pole tip progressively decreases with an increasing distance from an air-bearing surface, in a direction of an element height.
    Type: Application
    Filed: April 27, 2007
    Publication date: November 1, 2007
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Masafumi Mochizuki, Shuji Nishida, Kimitoshi Etoh, Isao Nunokawa
  • Publication number: 20070217066
    Abstract: Thin film perpendicular magnetic head with a narrow main pole capable of a high recording density in excess of 100 gigabits per square inch and generating a high magnetic recording field exceeding 10 kOe (oersted), while also modified to suppress remanent magnetic fields occurring immediately after writing operation. In a perpendicular magnetic head comprising a main pole, a return path for supplying a magnetic flux to that main pole, and an conductive coil for excitation of the main pole and return path, the main pole has a pole width of 200 nanometers or less, and a magnetic multilayer made up of a high saturation flux density layer and low saturation flux density layer, the low saturation flux density layer has a thickness within 0.5 to 5 nanometers, the high saturation flux density layer has a thickness from 10 to 50 nanometers for suppressing remanent magnetization and preventing erasing after writing by utilizing a closed magnetic domain structure in the pole.
    Type: Application
    Filed: May 22, 2007
    Publication date: September 20, 2007
    Inventors: Yoshiaki Kawato, Kazuhiro Nakamoto, Hiroyuki Hoshiya, Yasuyuki Okada, Masafumi Mochizuki
  • Publication number: 20070211382
    Abstract: Embodiments in accordance with the present invention provide a magnetic head in which broadening of the write-field distribution in the track-width direction can be decreased without reducing the write-field intensity. A main pole includes a pole tip having a part which provides the write track-width and a yoke part recessed from the air bearing surface in the element height direction, the pole tip including at least two magnetic films having different track-width directions, and the throat height at the trailing side being made smaller than the throat height at the leading side.
    Type: Application
    Filed: February 15, 2007
    Publication date: September 13, 2007
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Masafumi Mochizuki, Kimitoshi Etoh, Youji Maruyama, Hiroshi Fukui
  • Publication number: 20070188921
    Abstract: Embodiments in accordance with the present invention provide a magnetic head in which broadening of the effective track width can be decreased without reducing the write-field intensity and a variation of the track width can be decreased. A main pole consists of a pole tip having a part which provides the write track-width and a yoke part recessed from the air beating surface in the element height direction, and the pole tip consists of a pole tip at the trailing side where the width in the track-width direction is large and a pole tip at the leading side where the width in the track width direction is small. Moreover, the throat height of the pole tip at the trailing side is made greater than the throat height of the pole tip at the leading side.
    Type: Application
    Filed: February 15, 2007
    Publication date: August 16, 2007
    Applicant: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: Masafumi Mochizuki, Kimitoshi Etoh, Yoji Maruyama, Hiroshi Fukui