Leakage Magnetic Field Patents (Class 369/13.15)
  • Publication number: 20130114384
    Abstract: A magnetic head, according to one embodiment, includes a magnetized high-speed rotor placed in the vicinity of a main magnetic pole, wherein the main magnetic pole generates a magnetized rotating magnetic field, wherein information is recorded by generating a high-frequency magnetic field from the magnetized high-speed rotor and switching the magnetic head between a magnetic resonance state and a magnetization state, and wherein the magnetic head has a structure such that leaking is reduced for magnetic fields applied parallel to a magnetized rotating surface of the magnetized high-speed rotor from the main magnetic pole. Additional systems and methods are also presented.
    Type: Application
    Filed: December 21, 2012
    Publication date: May 9, 2013
    Applicant: HGST NETHERLANDS B.V.
    Inventor: HGST Netherlands B.V.
  • Patent number: 8149652
    Abstract: An apparatus comprises a storage medium, a recording head, a source of electromagnetic radiation, and a control circuit for modulating the source of electromagnetic radiation in response to a static deviation of a spacing between the recording head and the storage medium. A method of compensating a static deviation of a spacing between a recording head and a storage medium performed by the apparatus, and a method of precompensating for nonlinear transition shifts in a heat assisted magnetic recording system, are also provided.
    Type: Grant
    Filed: March 10, 2009
    Date of Patent: April 3, 2012
    Assignee: Seagate Technology LLC
    Inventors: Mehmet Fatih Erden, Priyadarshee Deeptarag Mathur, William Albert Challener, Edward Charles Gage, Wei Peng, Terry Wayne McDaniel, Tim Rausch
  • Patent number: 7602674
    Abstract: An optical recording medium 10 is recorded and reproduced with irradiation of light L and recorded pits are recorded with irradiation of light L through an objective lens 4 of which numerical aperture is greater than 1, at least a silicon layer 3 and a silicon oxide layer 2 being formed from the light irradiation side, in that order. An optical recording medium and an optical recording and reproducing method thereof are suitable for use with a near-field optical recording and reproducing system using an objective lens of which numerical aperture is greater than 1.
    Type: Grant
    Filed: April 16, 2004
    Date of Patent: October 13, 2009
    Assignee: Sony Corporation
    Inventor: Masataka Shinoda
  • Publication number: 20040125704
    Abstract: An optical device is provided including a conductive film having first and second surfaces, at least one aperture provided in the conductive film and extending from the first surface to the second surface, and a surface topography formed on at least one of the first and second surfaces, wherein said surface topography increases an intensity of light incident onto one of said first and second surfaces and transmitted through said aperture, wherein a region on which the surface topography is formed is larger than a region where the light is incident on the conductive film surface, and the aperture is formed on the region on which the surface topography is formed.
    Type: Application
    Filed: July 22, 2003
    Publication date: July 1, 2004
    Applicant: NEC CORPORATION
    Inventors: Tsutomu Ishi, Junichi Fujikata, Hitoshi Yokota, Kunio Kato
  • Publication number: 20040027928
    Abstract: A magneto-optical recording medium has magneto-optical recording layers (11, 12, 13) and reproducing layers (21, 22, 23). The information recorded in the reproducing layers are reproduced by means of reproducing light beams (31, 32, 33) of different wavelengths, respectively. In reproduction, magnetic domains (4) recorded in the recording layers are transferred in the reproducing layers formed on the respective recording layers, the transferred magnetic domains (5) are enlarged with an external magnetic field, and the information is reproduced. Since information is recorded and reproduced for each recording layer, the recording density is improved. Further since the reproduction signals are amplified by the magnetic domain enlargement, the C/N is improved.
    Type: Application
    Filed: June 3, 2003
    Publication date: February 12, 2004
    Applicant: Hitachi Maxell, Ltd.
    Inventors: Hiroyuki Awano, Katsusuke Shimazaki, Hiroki Takao, Norio Ohta, Akiyoshi Itou, Katsuji Nakagawa
  • 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: 6678219
    Abstract: Featured is a magneto-optical storage medium including: a first magnetic layer constituted by a perpendicularly magnetized film; a second magnetic layer constituted by a perpendicularly magnetized film so as to be exchange coupled to the first magnetic layer; and a third magnetic layer magnetostatically coupled to the first and second magnetic layers at elevated temperatures, magnetization of the first magnetic layer being copied to the third magnetic layer. The second magnetic layer produces a greater peak net magnetization, has a higher Curie temperature than the first magnetic layer and produces a leaking magnetic flux. The structure enhances magnetostatic coupling forces acting between the first magnetic layer and the second magnetic layer and also between the first magnetic layer and the third magnetic layer.
    Type: Grant
    Filed: November 2, 2000
    Date of Patent: January 13, 2004
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Junji Hirokane, Noboru Iwata
  • Patent number: 6560168
    Abstract: An information recording apparatus using a recording medium which holds information by reversed magnetic domains on a perpendicular magnetic recording film includes an irradiation unit for applying electromagnetic energy or light onto the recording medium, and a magnetic flux detection unit for detecting magnetic leakage flux emerging from the recording medium, the magnetic flux detection unit being disposed on the same side as the irradiation unit with respect to the recording medium. As a result, both side recording of the recording medium can be conducted.
    Type: Grant
    Filed: December 12, 2000
    Date of Patent: May 6, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Hideki Saga, Hiroaki Nemoto, Hirofumi Sukeda, Masahiko Takahashi, Kimio Nakamura, Yohji Maruyama, Hiroshi Ide, Takehiko Hamaguchi
  • Patent number: 6483783
    Abstract: A magnetic head is configured of a core and a coil wound around the core and passing current through the coil in a variable direction allows the core to have an edge generating an alternating magnetic field Hex1 and another edge generating an alternating magnetic field Hex2. Alternating magnetic fields Hex1 and Hex2 are applied to the respective edges. Furthermore, a laser beam LB1 is directed such that its optical axis L01 matches the edge receiving the alternating magnetic field Hex1, and a laser beam LB2 is directed such that its optical axis L02 matches the edge receiving the alternating magnetic field Hex2. A first magneto-optical signal detected through the alternating magnetic field Hex1 and the laser beam LB1 and a second magneto-optical signal detected through the alternating magnetic field Hex2 and the laser beam LB2 are composited together.
    Type: Grant
    Filed: November 16, 2000
    Date of Patent: November 19, 2002
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Kenichiro Mitani, Naoyuki Takagi, Hitoshi Noguchi, Hiroki Ishida, Atsushi Yamaguchi, Morio Nakatani
  • Patent number: 6477118
    Abstract: Disclosed are a reproducing method and a reproducing apparatus capable of performing reproduction with a wide power margin, as well as a recording method and a recording apparatus preferably used for super high density recording. A recording and reproducing apparatus 101 principally comprises a magnetic field-applying unit, a laser beam-radiating section, and a signal processing system. A magnetic coil 29, which is provided for the magnetic field-applying unit, is arranged so that its axis of magnetic field generation 102 is oblique to a surface of an information-recording medium 100. A reproducing magnetic field is applied in an oblique direction to the surface of the information-recording medium 100 by using the magnetic coil 29 while radiating a reproducing light beam to the medium by using the laser beam-radiating section. Accordingly, the leak magnetic field in the in-plane direction from a recording magnetic domain in a recording layer is amplified.
    Type: Grant
    Filed: November 26, 1999
    Date of Patent: November 5, 2002
    Assignee: Hitachi Maxell, Ltd.
    Inventors: Hiroyuki Awano, Masaki Sekine, Manabu Tani, Masafumi Yoshihiro, Hiroshi Ido
  • Publication number: 20020034128
    Abstract: A magneto-optical disk apparatus includes a magnetic head in a position opposed to an objective lens included in an optical head with a magneto-optical record medium therebetween. The magneto-optical disk apparatus includes a magnet for cancelling a first magnetic field emitted toward the magnetic head from a magnet for focus servo-control or tracking servo-control of the objective lens. The magnet emits a second magnetic field in a direction toward the magnetic head. The second magnetic field is opposite in direction to the first magnetic field, and has the same intensity as the first magnetic field. Consequently, the signal can be accurately reproduced from the magneto-optical record medium while removing a magnetic influence from the magnet included in the optical head.
    Type: Application
    Filed: September 17, 2001
    Publication date: March 21, 2002
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Masaaki Shidochi, Kanichi Koyama, Yoichi Tsuchiya, Mitsuhiko Maeda, Seiji Kajiyama, Seiichiro Takahashi