Reading Patents (Class 369/13.05)
  • Patent number: 11004468
    Abstract: According to one embodiment, a magnetic disk device includes a disk, a head which writes data to the disk and reads data from the disk, and a controller which increases a first recording density of data to be written to a first sector having a first overwrite in the first sector and reduces a second recording density of data to be written to a second sector having a second overwrite different from the first overwrite, on a first track of the disk.
    Type: Grant
    Filed: March 4, 2020
    Date of Patent: May 11, 2021
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage Corporation
    Inventors: Nobuhiro Maeto, Yusuke Tomoda
  • Patent number: 10908923
    Abstract: The present disclosure relates to application starting methods and terminal devices. One example method includes detecting, by a terminal device, magnetic field strength, and when the magnetic field strength is greater than a magnetic field strength threshold, starting, by the terminal device, an application corresponding to the magnetic field strength threshold.
    Type: Grant
    Filed: October 31, 2016
    Date of Patent: February 2, 2021
    Assignee: Huawei Technologies Co., Ltd.
    Inventors: Kun Wang, Nan Yang, Jun Yu, Xi Li
  • Patent number: 9466318
    Abstract: Some embodiments described herein are directed to reducing or eliminating latency caused by data zone switches in a rotating magnetic storage device. More specifically, some embodiments described herein are directed to storing parameters associated with different zones in a parameter register in response to one or more received commands.
    Type: Grant
    Filed: January 20, 2016
    Date of Patent: October 11, 2016
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Davide Giovenzana, Paul E. Soderbloom
  • Publication number: 20130322220
    Abstract: A system for stabilizing optical tape passing in front of one or more optical pickup units (OPUs) in an optical tape drive. The system includes at least one stabilizing apparatus having a pair of stabilizing members (e.g., partially convex members placed proximate each other) located opposite at least one OPU along the path of a length of optical tape. Each stabilizing member has a support portion (e.g., crown) over which the optical tape passes as the tape is being written to or read by the OPU. The support portion of one stabilizing member is spaced from the support portion of the other stabilizing member by a depression or recess over which the optical tape passes as it moves between the first and second support members. The OPU may direct laser beams at a relatively short, planar span of unsupported optical tape over the depression as part of read/write operations.
    Type: Application
    Filed: May 31, 2012
    Publication date: December 5, 2013
    Applicant: ORACLE INTERNATIONAL CORPORATION
    Inventors: Daniel Underkofler, Steven Suttle
  • Patent number: 8588037
    Abstract: A magnetic disk device of an embodiment includes a magnetic disk, a magnetic head, a laser-beam-intensity control unit, a reproduced-signal detecting unit, and a magnetic-disk evaluating unit. The magnetic head reads a signal recorded in the magnetic disk, or performs magnetic recording while irradiating a laser beam onto the magnetic disk. The laser-beam-intensity control unit controls the intensity of the laser beam. The reproduced-signal detecting unit detects the signal read by the magnetic head. The magnetic-disk evaluating unit evaluates the signal read from the magnetic head, on the basis of a relation between a noise level detected from the signal read by the magnetic head, and the intensity of the laser beam.
    Type: Grant
    Filed: March 13, 2012
    Date of Patent: November 19, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yuuichi Yamada, Tomoko Taguchi, Yoshinobu Fuchizaki
  • Publication number: 20130176835
    Abstract: A magnetic disk device of an embodiment includes a magnetic disk, a magnetic head, a laser-beam-intensity control unit, a reproduced-signal detecting unit, and a magnetic-disk evaluating unit. The magnetic head reads a signal recorded in the magnetic disk, or performs magnetic recording while irradiating a laser beam onto the magnetic disk. The laser-beam-intensity control unit controls the intensity of the laser beam. The reproduced-signal detecting unit detects the signal read by the magnetic head. The magnetic-disk evaluating unit evaluates the signal read from the magnetic head, on the basis of a relation between a noise level detected from the signal read by the magnetic head, and the intensity of the laser beam.
    Type: Application
    Filed: March 13, 2012
    Publication date: July 11, 2013
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Yuuichi Yamada, Tomoko Taguchi, Yoshinobu Fuchizaki
  • Patent number: 8270283
    Abstract: There is herein described a Transmedian Storage and Transfer Device (TSTD) that will provide a more useful system for information storage, retrieval, and computation. This is achieved by increasing the speed and storage capacity beyond that provided by existing computers and related systems. To obtain these benefits, the TSTD utilizes a spherical surface for information storage along with a system detector that can be point-like, line-like, or spherical. Further more, multiple spheres can be incorporated into the TSTD thus resulting in a sphere matrix.
    Type: Grant
    Filed: September 18, 2002
    Date of Patent: September 18, 2012
    Inventors: Jack V. Smith, Ben T. Foster
  • Patent number: 8023393
    Abstract: The present invention relates to a method of reducing the wear of a tip of a probe when the tip is in contact with a surface of a substrate and when the probe is mounted on a support structure. A method is provided where a load force is applied to the probe, thereby causing the tip to be maintained substantially in contact with the substrate surface and a modulation step where the e magnitude of the load force is modulated at a modulation frequency. The modulation frequency is selected to be greater than a fundamental vibration frequency of the support structure on which the probe is mounted.
    Type: Grant
    Filed: May 7, 2008
    Date of Patent: September 20, 2011
    Assignee: International Business Machines Corporation
    Inventors: Urs T. Duerig, Bernd W. Gotsmann, Armin W. Knoll, Mark Alfred Lantz
  • Patent number: 7945380
    Abstract: Method for navigating a vehicle in a road system is provided, in which method data is read from a data-storage medium and automatically transferred to a memory of a navigation device after the data medium is inserted into a data-media drive associated with the navigation device. The transferred data remains available for vehicle navigation even after the data medium is removed from the data-media drive.
    Type: Grant
    Filed: September 6, 2002
    Date of Patent: May 17, 2011
    Assignee: Robert Bosch GmbH
    Inventor: Andre Barkowski
  • Patent number: 7920458
    Abstract: An optical recording medium is provided with at least a substrate, light absorbing and heat generating parts each of which absorbs light and generates heat, and recording parts, and each of the recording parts are formed between two recording tracks.
    Type: Grant
    Filed: April 20, 2006
    Date of Patent: April 5, 2011
    Assignee: Ricoh Company, Ltd.
    Inventor: Hiroshi Miura
  • Patent number: 7474436
    Abstract: A photographic printing system includes a film reader for reading photographic image of a photographic film, a printer for printing the photographic image on an image recording medium based on photographic image data obtained through the film reader, a writer for writing at least the photographic image data in a loaded optical disc of the WORM (Write Once Read Many) type, and a controller for controlling the writing process of the writer. The controller allows writing, in the optical disc, of both the image data and a display processing program for displaying the image data written in the optical disc on a monitor when the optical disc has no data pre-written therein and allows writing, in the optical disc, of the image data when the optical disc has such display processing program pre-written therein.
    Type: Grant
    Filed: April 14, 2003
    Date of Patent: January 6, 2009
    Assignee: Noritsu Koki Co., Ltd.
    Inventors: Masahide Ohue, Shoichi Nakano
  • Publication number: 20080259743
    Abstract: The present invention relates to a method, apparatus and record carrier for controlling read-out and/or synchronization between an external magnetic field and written data during a reading operation from a magneto-optical recording medium comprising a storage layer and a read-out layer. An expanded domain leading to a pulse in a reading signal is generated in said read-out layer by copying a mark region from said storage layer to said read-out layer upon heating by a radiation power and with the help of the external magnetic field. The waveform of the reading signal is analyzed, and the analyzing result is used for correcting a phase deviation and/or for controlling a copy window size of the mark copying. Thereby, phase errors can be corrected for any size of the copy window. Even small changes in the copy window can be detected and corrected.
    Type: Application
    Filed: March 3, 2008
    Publication date: October 23, 2008
    Applicant: KONINKLIJKE PHILIPS ELECTRONICS, N.V.
    Inventor: COEN ADRIANUS VERSCHUREN
  • Patent number: 7200072
    Abstract: A recording/reproducing apparatus for a domain-wall-displacement magneto-optical recording medium with good format efficiency, capable of providing a good reproduction signal and securing a maximum recording region for a user is provided which comprises a recording circuit that starts recording of an information in a data region at a predetermined timing with a detection signal obtained in the preformat region being used as a reference, and a reproducing circuit that starts reproducing of the information recorded in the data region at a timing earlier than the predetermined timing with the detection signal being used-as a reference.
    Type: Grant
    Filed: July 9, 2003
    Date of Patent: April 3, 2007
    Assignee: Canon Kabushiki Kaisha
    Inventor: Katsumi Arisaka
  • Patent number: 7161875
    Abstract: A thermal-assisted probe based magnetic memory storage device. In a particular embodiment, magnetic tunnel junction memory cells and at least one movable probe with a tip characterized by a conductor and a heat generator are provided. The movable probe may be placed in electrical and thermal contact with a given memory cell. The memory cells include a material wherein the coercivity is decreased upon an increase in temperature. The magnetic field provided by the read conductor will not alter the orientation of an unheated cell, but may alter the orientation of a heated cell. A related method of use is also provided.
    Type: Grant
    Filed: June 12, 2003
    Date of Patent: January 9, 2007
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventor: Manish Sharma
  • Patent number: 7126883
    Abstract: An optical information reproducing method of the present invention is used for an optical recording medium. The optical recording medium includes a recording layer containing information and a mask layer that is located close to the recording layer and includes a nonlinear optical material whose optical properties are changed in accordance with incident light intensity. The method includes irradiating the optical recording medium with convergent light that is polarized in a first direction and dividing reflected light from the optical recording medium into a first polarized component that is polarized in the first direction and a second polarized component that is polarized in a second direction perpendicular to the first direction. The second polarized component is used to detect a reproduction signal.
    Type: Grant
    Filed: October 9, 2002
    Date of Patent: October 24, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroaki Yamamoto, Teruhiro Shiono
  • Patent number: 6920091
    Abstract: There is provided an optical reproduction apparatus and an optical recording and reproduction apparatus which can improve a CNR and can read at high speed. The center portion of a laser light emitted from a semiconductor laser is shaded by a light shading portion of a first light shade, and its peripheral portion is condensed and irradiates a super-resolution film of an optical disk. The center portion of a reflected light from the optical disk is mainly made of a signal component, and a noise component almost disappears. Thus, the reflected light from the optical disk is separated into the center portion and its peripheral portion, and the reflected light made of the signal component of the center portion is used for signal reproduction, so that the CNR can be increased.
    Type: Grant
    Filed: January 30, 2001
    Date of Patent: July 19, 2005
    Assignee: Fuji Xerox Co., Ltd.
    Inventor: Kiichi Ueyanagi
  • Publication number: 20040252590
    Abstract: A thermal-assisted probe based magnetic memory storage device. In a particular embodiment, magnetic tunnel junction memory cells and at least one movable probe with a tip characterized by a conductor and a heat generator are provided. The movable probe may be placed in electrical and thermal contact with a given memory cell. The memory cells include a material wherein the coercivity is decreased upon an increase in temperature. The magnetic field provided by the read conductor will not alter the orientation of an unheated cell, but may alter the orientation of a heated cell. A related method of use is also provided.
    Type: Application
    Filed: June 12, 2003
    Publication date: December 16, 2004
    Inventor: Manish Sharma
  • Patent number: 6801478
    Abstract: There is disclosed a magneto-optical information reproducing apparatus which can perform information reproducing with a low crosstalk level, and the apparatus comprises a biasing electromagnet 19 for generating a reproducing magnetic field, and an MPU 26 for adjusting an intensity of the magnetic field generated by the biasing electromagnet 19 with respect to a land and a groove so that with respect to one of the land and the groove in which reproducing object information is recorded, a level of a crosstalk attributed to the information recorded in the other one of the land and the groove is lowered.
    Type: Grant
    Filed: September 29, 2000
    Date of Patent: October 5, 2004
    Assignee: Fujitsu Limited
    Inventor: Hideki Nishimoto
  • Patent number: 6771567
    Abstract: A magneto-optical read head for detecting magnetic transitions representing data stored in a magnetic recording medium as a sense layer having an optical property that is magnetic field-dependent, two magnetic shield layers respectively disposed on opposite sides of the sense layer and allowing magnetic flux from substantially only one of the magnetic transitions to interact with the sense layer at a time, with one of the magnetic shield layers being transparent at a wavelength allowing light at that wavelength to enter into and exit from the sense layer.
    Type: Grant
    Filed: November 6, 2001
    Date of Patent: August 3, 2004
    Assignee: O-Mass AS
    Inventors: Jean-Pierre Nozieres, Sebastien Ferrand, Yannick Maral, Jean-Christophe Toussaint, Jørn Raastad
  • 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: 20040062152
    Abstract: A device for writing data to a recording medium and a method for fabricating the device is presented. According to one embodiment, the device includes an electrical conductor having a cross-track portion, wherein the cross-track portion includes first and second opposing surfaces, and wherein the cross-track portion defines an aperture extending from the first surface to the second surface. The device also includes a dielectric portion disposed in the aperture such that the dielectric portion defines a ridge waveguide having a lowest-order mode cut-off frequency that is less than the frequency of incident optical energy used to heat the recording medium.
    Type: Application
    Filed: September 27, 2002
    Publication date: April 1, 2004
    Inventors: Daniel D. Stancil, Amit V. Itagi, Tuviah E. Schlesinger, James A. Bain, Tim Rausch
  • Publication number: 20040052164
    Abstract: There is herein described a Transmedian Storage and Transfer Device (TSTD) that will provide a more useful system for information storage, retrieval, and computation. This is achieved by increasing the speed and storage capacity beyond that provided by existing computers and related systems. To obtain these benefits, the TSTD utilizes a spherical surface for information storage along with a system detector that can be point-like, line-like, or spherical. Further more, multiple spheres can be incorporated into the TSTD thus resulting in a sphere matrix.
    Type: Application
    Filed: September 18, 2002
    Publication date: March 18, 2004
    Inventors: Jack V. Smith, Ben T. Foster
  • Patent number: 6693854
    Abstract: External magnetic fields H(x) or reproducing light beams L(x) having different intensity patterns are applied to an identical recording position on a magneto-optical recording medium so that different pieces of information corresponding to the patterns are reproduced from the identical recording position. A function H(x) or L(x) is a password for obtaining the information. Only a person, who knows the function, can access specified information recorded on the magneto-optical recording medium. The function H(x) or L(x) is a function in which the magnetic field intensity or the light intensity is modulated with respect to the recording position x so that magnetic domains may be thinned out to perform reproduction at a specified cycle from continuous magnetic domains in a recording area.
    Type: Grant
    Filed: March 17, 2003
    Date of Patent: February 17, 2004
    Assignee: Hitachi Maxwell, Ltd.
    Inventors: Katsusuke Shimazaki, Susumu Imai, Norio Ohta, Hiroyuki Awano, Masafumi Yoshihiro, Hitoshi Watanabe, Hiroki Takao
  • Patent number: 6687194
    Abstract: A read retry of an MSR medium is executed while changing a setting of a reproducing magnetic field. Parameter set values of a successful read retry are stored as statistic information. When changes of the set values for defaults increase, the defaults are updated. The parameter set information of a retry success is stored as statistic information. In a new read retry, the parameter set information of a high success ratio is selected from the statistic information and the retry is executed.
    Type: Grant
    Filed: August 13, 1999
    Date of Patent: February 3, 2004
    Assignee: Fujitsu Limited
    Inventors: Shinya Kobayashi, Shigenori Yanagi, Teruji Yamakawa, Kiyomi Imamura
  • 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
  • Publication number: 20030227831
    Abstract: The present invention is a method of reading and writing in MAMMOS that uses the edge of the thermal profile for detection of a domain rather than using the tip of the profile. By using the edge, it is possible to detect the position of domains rather than merely the presence of domains. Thus, domain positions are used to store data. By measuring these positions relative to the last domain, more accuracy can be gained. The new scheme is called Domain Position Detection for MAMMOS (DPD-MAMMOS). In DPD-MAMMOS, the information is encoded into the MAMMOS media in the form of the position of the domains rather than the presence of the domains. In this way, each domain stored in the media can contain several bits or possibly bytes of information. Methods of reading and writing information are disclosed.
    Type: Application
    Filed: June 7, 2002
    Publication date: December 11, 2003
    Inventor: Philipp Herget
  • Patent number: 6646968
    Abstract: Disclosed herein is a testing process for recording for presetting optimum recording power for a domain wall displacement type magneto-optical medium, the process comprising the steps of: recording a first record pattern on an Nth track on the magneto-optical medium; separately recording a second record pattern on an (N−1)th track and an (N+1)th track adjacent to both sides of the Nth track with varied recording power; reproducing the Nth track to detect a change in the pulse width of a reproduction signal; detecting recording power, at which cross writing occurs, on the basis of the detected result; and presetting optimum recording power on the basis of the recording power at which cross writing occurs.
    Type: Grant
    Filed: June 29, 2000
    Date of Patent: November 11, 2003
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yasuyuki Miyaoka
  • Publication number: 20030179657
    Abstract: A magneto-optical disk apparatus (100) includes an optical pickup (101) and a magnetic head (113). The optical pickup (101) irradiates a magneto-optical recording medium (10) with a laser beam of such intensity that a part of a reproducing layer of the magneto-optical recording medium (10) is heated to a temperature over the compensation temperature. The magnetic head (113) applies to the magneto-optical recording medium (10) a DC magnetic field having intensity weaker than the intensity at which magnetization of a transition-metal-rich area in a part of the reproducing layer heated to a temperature over the compensation temperature is inverted. The optical pickup (101) detects a magneto-optical signal varying in intensity between two levels. As a result, a signal can be reproduced correctly from the magneto-optical recording medium (10) by a magnetic domain enlargement system.
    Type: Application
    Filed: September 16, 2002
    Publication date: September 25, 2003
    Inventors: Hitoshi Noguchi, Atsushi Yamaguchi, Hiroki Ishida, Naoyuki Takagi, Kenichiro Mitani
  • Publication number: 20030161221
    Abstract: External magnetic fields H(x) or reproducing light beams L(x) having different intensity patterns are applied to an identical recording position on a magneto-optical recording medium so that different pieces of information corresponding to the patterns are reproduced from the identical recording position. A function H(x) or L(x) is a password for obtaining the information. Only a person, who knows the function, can access specified information recorded on the magneto-optical recording medium. The function H(x) or L(x) is a function in which the magnetic field intensity or the light intensity is modulated with respect to the recording position x so that magnetic domains may be thinned out to perform reproduction at a specified cycle from continuous magnetic domains in a recording area.
    Type: Application
    Filed: March 17, 2003
    Publication date: August 28, 2003
    Applicant: HITACHI MAXELL, LTD.
    Inventors: Katsusuke Shimazaki, Susumu Imai, Norio Ohta, Hiroyuki Awano, Masafumi Yoshihiro, Hitoshi Watanabe, Hiroki Takao
  • 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
  • Publication number: 20030117905
    Abstract: A reproducing laser output can be adjusted to an optinal level. To this end, a magneto-optical disk device 1 comprises a differential amplifier 23 and a shortest recording mark identifier 33 which detect a shortest recording mark reproducing signal corresponding to a component of a shortest recording mark in a reproducing signal obtained by reproducing a magneto-optical disk 100, an envelope detector 33 which detects an amplitude level of the shortest recording mark reproducing signal, a comparator 35 which compares the amplitude level with a reference voltage outputted from the reference voltage source 34, and a drive control section 30 which adjusts the reproducing laser beam to an output level at which the amplitude level is equal to or higher than the reference voltage, based on a comparison result from the comparator 35.
    Type: Application
    Filed: February 14, 2003
    Publication date: June 26, 2003
    Applicant: Sony Corporation
    Inventors: Keiichi Tsutsui, Yasuyuki Takeshita
  • Publication number: 20030086340
    Abstract: A magneto-optical read head for detecting magnetic transitions representing data stored in a magnetic recording medium as a sense layer having an optical property that is magnetic field-dependent, two magnetic shield layers respectively disposed on opposite sides of the sense layer and allowing magnetic flux from substantially only one of the magnetic transitions to interact with the sense layer at a time, with one of the magnetic shield layers being transparent at a wavelength allowing light at that wavelength to enter into and exit from the sense layer.
    Type: Application
    Filed: November 6, 2001
    Publication date: May 8, 2003
    Inventors: Jean-Pierre Nozieres, Sebastien Ferrand, Yannick Maral, Jean-Christophe Toussaint, Jorn Raastad
  • Patent number: 6519210
    Abstract: A reproducing magnetic field correcting unit is provided, a reproducing state is monitored while increasing a reproducing magnetic field by using a predetermined reproducing magnetic field as an initial value H1, and a reproducing magnetic field when a reproducible state is obtained is determined as an optimum magnetic field. A reproducing magnetic field obtained by adding a predetermined value to the reproducing magnetic field in the reproducible state is used as an optimum reproducing magnetic field. A change in reproducing magnetic field is started from the low magnetic field in which a predetermined value is subtracted from the initial value. A shoulder portion is certainly detected and the optimum magnetic field is set.
    Type: Grant
    Filed: December 18, 2000
    Date of Patent: February 11, 2003
    Assignee: Fujitsu Limited
    Inventors: Toru Ikeda, Shigenori Yanagi
  • Patent number: 6515814
    Abstract: The present invention provides a magnetic signal reproducing device including heating means for locally heating a reproducing region of a magnetic recording medium, first reproducing means for reading magnetic information in the reproducing region in a first temperature state to obtain a first reproduced signal, second reproducing means for reading magnetic information in almost the same region as the reproducing region in a second temperature state which is different from the first temperature state to obtain a second reproduced signal, and correcting means for correcting the first reproduced signal based on the second reproduced signal to obtain an information reproducing signal representing information recorded in the reproducing region. According to this, even if a medium temperature in a non-heated region of the magnetic recording medium is shifted from a magnetization compensation point, a signal from the region is prevented from mixing into a reproducing signal.
    Type: Grant
    Filed: January 28, 2000
    Date of Patent: February 4, 2003
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masaki Hamamoto, Junichi Sato, Yasushi Ogimoto, Kunio Kojima
  • Patent number: 6469960
    Abstract: In an information storage apparatus for recording information in a recording medium by applying an external magnetic field to a position illuminated by the light beam, an external magnetic field control part controls an external magnetic field strength based on the illuminated position on the recording medium.
    Type: Grant
    Filed: March 31, 2000
    Date of Patent: October 22, 2002
    Assignee: Fujitsu Limited
    Inventor: Yasuo Miyoshi
  • Publication number: 20020141293
    Abstract: A magneto-optical storage medium that protects against the effects of cross-talk, making it possible to further reduce the level of track density, and which also makes it possible to conduct high-density recording/playback with a reduced magnetic field for erasure and a favorable level of playback signal quality. More specifically, a magneto-optical storage medium, which includes at least the following laminated layers, in the following order: a playback layer, a non-magnetic layer, a transfer layer, a cut-off layer, and a recording layer. The playback layer preferably displays easy in-plane magnetization characteristics within the monolayer at room temperature, and the transfer layer and the recording layer each have easy magnetization characteristics in the vertical direction of the monolayers at room temperature when each layer is considered as a monolayer.
    Type: Application
    Filed: March 22, 2002
    Publication date: October 3, 2002
    Applicant: Fujitsu Limited
    Inventor: Tetsuo Hosokawa
  • Patent number: 6399174
    Abstract: A magnetooptical recording medium includes a first magnetic layer, a second magnetic layer whose Curie temperature is lower than that of the first magnetic layer, and a third magnetic layer, comprising a vertically-magnetizing film, whose Curie temperature is higher than that of the second magnetic layer. The first magnetic layer, the second magnetic layer and the third magnetic layer are in a state of exchange coupling with each other at a portion of a vertically-magnetizing film. A domain walls formed in the first magnetic layer moves when the temperature of the medium has been raised to at least the Curie temperature of the second magnetic layer.
    Type: Grant
    Filed: October 13, 2000
    Date of Patent: June 4, 2002
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tsutomu Shiratori, Tomoyuki Hiroki
  • Publication number: 20020048225
    Abstract: Information is recorded on a light transmission material such as a light transmission substrate (1) or a light transmission protecting film as a change of refractive index or a change of extinction coefficient or a change of transmittance or a change of reflectance
    Type: Application
    Filed: June 28, 2001
    Publication date: April 25, 2002
    Inventor: Masataka Shinoda
  • Publication number: 20010046100
    Abstract: An information reproducing element formed by a plurality of transferring portions sandwiching magnetically insulatable regions is arranged so as to face an information recording medium. A plurality of record marks on the information recording medium are mutually insulatedly transferred onto the information reproducing element. A light beam is irradiated onto the information reproducing element. The record marks recorded by high density recording are then reproduced by magneto-optical reproduction or maximum-likelihood detection.
    Type: Application
    Filed: June 4, 2001
    Publication date: November 29, 2001
    Applicant: FUJITSU LIMITED
    Inventor: Masakazu Taguchi