Light Beam Transducer Assembly Patents (Class 369/13.32)
  • Patent number: 7483229
    Abstract: In a recording transducer, radiant energy is incident to be coupled to a recording head via a path defined in the support (e.g., slider) for the head. The radiant energy may be directed via a fiber or lens (e.g., MEMS lens) through a channel defined in the slider. The slider may be keyed to accept the fiber or lens. The process for fabricating the channel in the slider the channel may include wafer level processing to form holes in the slider, to accept the fiber or lens. Wafer level MEM optical processing may be deployed to form integrated MEMS lens structures for an array of sliders.
    Type: Grant
    Filed: December 8, 2004
    Date of Patent: January 27, 2009
    Assignee: Seagate Technology LLC
    Inventors: Tim Rausch, Patrick Breckow Chu
  • Patent number: 7463401
    Abstract: An integrated micro-optical system includes at least two wafers with at least two optical elements provided on respective surfaces of the at least two wafers, at least one of the two optical elements being a spherical lens. The resulting optical system presents a high numerical aperture. One of the optical elements may be a refractive element formed in a material having a high index of refraction.
    Type: Grant
    Filed: November 18, 2002
    Date of Patent: December 9, 2008
    Assignee: Tessera North America, Inc.
    Inventors: Michael R. Feldman, Alan D. Kathman, William H. Welch
  • Patent number: 7444054
    Abstract: An apparatus comprises a thin film metallic layer, a first dielectric layer arranged on a first side of said thin film metallic layer and having a first index of refraction, a second dielectric layer arranged on the opposite side of said thin film metallic layer from said first dielectric layer, a third dielectric layer arranged on the first side of the thin film metallic layer adjacent to the first dielectric layer and having a second index of refraction that is lower than the first index of refraction, and wherein the thin film metallic layer, the first dielectric layer and the third dielectric layer are arranged to focus plasmon waves induced at an interface between the thin film metallic layer and the third dielectric layer.
    Type: Grant
    Filed: August 15, 2006
    Date of Patent: October 28, 2008
    Assignee: Seagate Technology LLC
    Inventor: William Albert Challener
  • Patent number: 7440660
    Abstract: An apparatus includes a first waveguide configured to focus an electromagnetic wave to a focal region, and a second waveguide defining an opening having an end positioned adjacent to the focal region, the second waveguide including a first metallic layer, and second and third layers positioned on opposite sides of the first metallic layer, wherein the first metallic layer has a first propagation constant larger than propagation constants of the second and third layers.
    Type: Grant
    Filed: October 16, 2007
    Date of Patent: October 21, 2008
    Assignee: Seagate Technology LLC
    Inventors: Xuhui Jin, Chubing Peng, William Albert Challener, Edward Charles Gage, Michael Allen Seigler
  • Patent number: 7412143
    Abstract: A transducer comprises a conductive pin and a waveguide for directing electromagnetic radiation onto the pin, wherein the pin is configured to create a rectangular flat top field distribution at a surface of a storage medium positioned adjacent to an end of the pin, leading to a flat top thermal profile within the storage medium. A second pin can be included in the transducer. Recording heads that include the transducer, disc drives that include the recording head, and a method of heating a portion of a storage medium that is performed by the recording head, are also included.
    Type: Grant
    Filed: September 20, 2004
    Date of Patent: August 12, 2008
    Assignee: Seagate Technology LLC
    Inventors: Robert Earl Rottmayer, Julius Kurt Hohlfeld, William Albert Challener, Chubing Peng, Edward Charles Gage
  • Patent number: 7330404
    Abstract: An optical transducer comprises an optical element for directing an electromagnetic wave to a focal region and a metallic nano-structure having a longitudinal axis substantially parallel to an electric field of the electromagnetic wave, the metallic nano-structure being positioned outside of the optical element, wherein the electromagnetic wave produces surface plasmons on the metallic nano-structure. A cladding material having a refractive index differing from the refractive index of the optical element can be positioned adjacent to a surface of the metallic nano-structure. Magneto-optical recording heads that include the transducers and disc drives that include the magneto-optical recording heads are also included.
    Type: Grant
    Filed: October 10, 2003
    Date of Patent: February 12, 2008
    Assignee: Seagate Technology LLC
    Inventors: Chubing Peng, William Albert Challener, Ibrahim Kursat Sendur
  • Publication number: 20070165494
    Abstract: A light delivery module, a method of fabricating the same, a heat-assisted magnetic recording head using the light delivery module are provided. The light delivery module delivers light emitted from a light source. The light delivery module includes an optical waveguide having an inclined plane of an angle ? with respect to an incident light axis to deliver an incident light, and a nano aperture changing an energy distribution of the light delivered through the inclined plane to generate an enhanced near-field. The heat-assisted magnetic recording head is mounted on one end of a slider with an air bearing surface to perform a recording operation on a recording medium. The heat-assisted magnetic recording head includes a magnetic path forming unit forming a magnetic field for recording, a light source emitting light for heating a predetermined region of a recording surface of the recording medium, and the light delivery module.
    Type: Application
    Filed: August 30, 2006
    Publication date: July 19, 2007
    Inventors: Eun-hyoung Cho, Sung-dong Suh, Hae-sung Kim, Myung-bok Lee, Jin-seung Sohn
  • Patent number: 7154820
    Abstract: An optical element structure allowing an increased power density of aperture-transmitted light while suppressing increase in temperature is disclosed. A conductive film has a sub-wavelength aperture formed therein and a periodic surface topography formed thereon. A lens focuses light onto the periodic surface topography with a predetermined diameter. The predetermined diameter of incident light on the conductive film and a period of the periodic surface topography are determined so that a power ratio of aperture-transmitted light to the light beam is greater than that of aperture-transmitted light which would be obtained if no periodic surface topography is provided in the conductive film.
    Type: Grant
    Filed: January 6, 2003
    Date of Patent: December 26, 2006
    Assignee: NEC Corporation
    Inventors: Matsafumi Nakada, Tineke Thio
  • Patent number: 7106935
    Abstract: An apparatus for focusing plasmon waves to a spot. The plasmon waves are there converted to light. In one application, the light is used for heat induced magnetic recording. In another application, the light is used as a part of near field scanning microscope. The plasmon waves may be induced on a converging rectangular cone having an aperture. The plasmon waves may also be focused on a flat surface by a curved dielectric lens. In the heat induced magnetic recording embodiment, a magnetic pole structure is integrated into the focusing apparatus, either as one surface of the rectangular cone, or as a layer upon which the curved dielectric lens is formed.
    Type: Grant
    Filed: January 6, 2003
    Date of Patent: September 12, 2006
    Assignee: Seagate Technology LLC
    Inventor: William Albert Challener
  • Patent number: 7006426
    Abstract: Light from a laser diode is directed by mirrors on angled surfaces of an optical unit through a first lens at an optical disc. Light returns from the disc on a parallel path through a second lens and is directed at a photodetector. A semiconductor device controls the operation of the laser diode and receives signals form the photodetector for processing. The optical unit is formed from one or two glass elements cut from a larger glass wafer or wafers using photolithographic techniques. The mirrors are formed by thin films deposited on angled glass surfaces formed by selective plasma etching of the wafers. At least one mirror is partially reflective and is formed by depositing a thin film of titanium nitride.
    Type: Grant
    Filed: December 18, 2001
    Date of Patent: February 28, 2006
    Assignee: STMicroelectronics, Inc.
    Inventors: Anthony M. Chiu, Danielle A. Thomas
  • Patent number: 6999384
    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: Grant
    Filed: September 27, 2002
    Date of Patent: February 14, 2006
    Assignee: Carnegie Mellon University
    Inventors: Daniel D. Stancil, Amit Itagi, Tuviah E. Schlesinger, James A. Bain, Tim Rausch
  • Patent number: 6996033
    Abstract: An optical path or waveguide for a laser-assisted transducing head is disclosed. The optical path extends between the poles of the transducing head to near the write gap. A solid-state laser is attached to or incorporated into the slider or head and is positioned to direct thermal energy through a waveguide and onto a track of a read/write surface to lower the coercivity of the recording medium to facilitate the write process.
    Type: Grant
    Filed: June 19, 2003
    Date of Patent: February 7, 2006
    Assignee: Advanced Research Corporation
    Inventors: Matthew P. Dugas, Jeffrey A. Wallhoff
  • Patent number: 6996043
    Abstract: Preceding to the reading out of the recording information of the optical disk by the pick-up, the height of the foreign material existing at the light converging position on the information reading surface is detected by the detector, and when the height of the foreign material is higher than the floating height h of the SIL, the magnetic field is generated by applying the control current corresponding to the height of the foreign material to the coil as the magnetic field generator at the timing before the foreign material is moved to the information reading position of the pick-up by the rotation of the optical disk. Then, when the magnetic field is provided to the magnetic substance fixedly holding the SIL which is floating, the movement operation to separate the SIL to the higher position than the height of the foreign material from the information reading surface together with the magnetic substance, is conducted.
    Type: Grant
    Filed: March 21, 2001
    Date of Patent: February 7, 2006
    Assignee: Pioneer Corporation
    Inventors: Osamu Kasono, Yoshiaki Kojima, Yasumitsu Wada
  • Patent number: 6958956
    Abstract: The disclosure relates to a magneto-optical reading device for multi-track magnetic tapes, including a flat large incident beam directed onto the active part of a magneto-optical read head and reflected by this head onto an array of sensors, characterized in that it includes a correction device able to move the zone of incidence of the beam on the read head in order to keep the beam optimally positioned on the active part of the read head as the latter suffers progressive wear. The invention increases the useful working life of such a reading device.
    Type: Grant
    Filed: August 4, 2000
    Date of Patent: October 25, 2005
    Assignee: Thales
    Inventors: Jean-Claude Jacquet, Stephane Bertrand, Françoise Le Texier
  • Patent number: 6876604
    Abstract: The present invention provides a magnetooptic device, a magnetooptic head, and a magnetic disk drive each capable of performing optically assisted magnetic recording and each having a small size, improved recording density, and a higher transfer rate. In a magnetooptic device, a magnetic circuit including a magnetic gap and a thin film magnetic transducer having a coil portion are stacked on the surface of a semiconductor laser. By the arrangement, optically assisted magnetic recording can be performed, small size and light weight are achieved, and higher transfer rate can be implemented.
    Type: Grant
    Filed: February 7, 2001
    Date of Patent: April 5, 2005
    Assignee: Fuji Xerox Co., Ltd.
    Inventor: Kiichi Ueyanagi
  • Patent number: 6873576
    Abstract: A method for thermally-assisted magnetic recording at an areal density above 100 Gb/in2 combines thermo-magnetic writing and optical or magnetic reading. In order to increase the stability of the recorded information, writing is carried out at an elevated temperature on a medium with a very high coercivity at room temperature. The magnetic write head determines the track width, allowing very small track widths, and the coercivity gradient resulting from the thermal gradient at the edge of the focused radiation spot, determines the bit length. The radiation may be varied so that the coercivity gradient at the trailing edge of the magnetic field is highest, when the magnetic field is switched.
    Type: Grant
    Filed: July 11, 2000
    Date of Patent: March 29, 2005
    Assignee: Koninklijke Philips Electronics N.V.
    Inventor: Hans Willem Van Kesteren
  • Patent number: 6834027
    Abstract: A read/write head for an optical storage medium is provided. The read/write head comprises a waveguide having an end face and a plasmon-enhanced device provided on the end face of the waveguide. The plasmon-enhanced device comprises a metal film having a first surface and a second surface, the first surface being fixed to the waveguide end face, the metal film having an aperture provided therethrough. The metal film has a periodic surface topography provided on at least one of the first and second surfaces of the metal film. Light incident on one of the surfaces of the metal film interacts with a surface plasmon mode on at least one of the surfaces of the metal film thereby enhancing transmission of light through the aperture in the metal film which is directed onto and/or collected from the optical storage medium. A read/write head with an integral light source is also provided.
    Type: Grant
    Filed: November 27, 2000
    Date of Patent: December 21, 2004
    Assignee: NEC Laboratories America, Inc.
    Inventors: Mitsuhito Sakaguchi, Tineke Thio, Richard A. Linke, Thomas W. Ebbesen, Henri J. Lezec
  • Patent number: 6819637
    Abstract: A magneto-optical disk drive that prevents the track shift signal from overlapping the MO signal, even when the optical head projects a divergent spherical wave onto the beam splitter. This objective is realized by a magneto-optical disk drive that uses an optical head which emits a divergent spherical wave onto a beam splitter surface of a beam splitter. Since the tracking error signal, which is overlapped by the MO signal of the MO detection unit, is synchronous with the tracking signal, a correction circuit is used to overlap the MO signal with the tracking error signal and to eliminate errors caused when the track shift signal overlaps the MO signal.
    Type: Grant
    Filed: September 12, 2000
    Date of Patent: November 16, 2004
    Assignee: Fujitsu Limited
    Inventors: Shin-ya Hasegawa, Nobuhide Aoyama
  • Patent number: 6795630
    Abstract: An apparatus for producing a small spot of optical energy comprises a planar waveguide shaped to direct a linearly polarized electromagnetic wave to a focal point within the waveguide, and a metallic pin positioned at the focal point whereby the linearly polarized electromagnetic wave creates surface plasmons on a surface of the pin. The apparatus can further comprise means for phase shifting a portion of the linearly polarized electromagnetic wave. Recording heads comprising a magnetic write pole, a planar waveguide positioned adjacent to the magnetic write pole, the planar waveguide being shaped to direct a linearly polarized electromagnetic wave to a focal point within the waveguide, and a metallic pin positioned at the focal point whereby the linearly polarized electromagnetic wave creates surface plasmons on a surface of the pin, and disc drives that use such recording heads are also disclosed.
    Type: Grant
    Filed: March 19, 2003
    Date of Patent: September 21, 2004
    Assignee: Seagate Technology LLC
    Inventors: William Albert Challener, Christophe Daniel Mihalcea, Tim Rausch
  • Patent number: 6781927
    Abstract: An optical data storage and retrieval system uses a flying head. The flying head is supported on a moving media having information stored in a plurality of stored data locations thereon. Information is stored in each of the plurality of media locations as physical structures capable of modulating the polarization state of incident light into one of two output polarization states. The flying head includes an optical processing assembly which directs an incident light beam having a source polarization state onto the moving media, accessing successive data locations. A reflected light beam having the source polarization state of the incident light beam modulated by a respective polarization modifying data location into one of the output polarization states is received by the flying head.
    Type: Grant
    Filed: November 9, 1999
    Date of Patent: August 24, 2004
    Assignee: Seagate Technology LLC
    Inventors: John F Heanuc, Jeffrey P. Wilde, Jerry E. Hurst, Jr., John H. Jerman
  • Patent number: 6762978
    Abstract: Recording/reproducing information signals to/from a recording medium appropriately even though the clearance from the signal recording surface of the recording medium to an optical head slider becomes significantly small. An optical head slider 10 includes a sliding member 11 which is floated and slides on a recording medium 4 at the time of recording/reproducing signals to/from the recording medium 4, a hemispheric objective lens 12 which is bonded to the sliding member 11, and a magnetic field generating means 16, which is mounted to the bottom of the sliding member 11 which faces the recording medium 4. The sliding member 11 is made of the same material as that of the optical lens 12, and a flat surface of the optical lens 12 is bonded to the top surface of the sliding member 11.
    Type: Grant
    Filed: September 18, 2001
    Date of Patent: July 13, 2004
    Assignee: Sony Corporation
    Inventors: Akio Mishima, Kenjiro Watanabe
  • Patent number: 6757221
    Abstract: An optical head includes a lens carrier movable at least radially of a magneto-optical disk in facing relation thereto. An object lens is mounted on the lens carrier to converge a laser beam for forming a laser spot on the disk. The object lens has an optical axis and includes a lens surface directed toward the disk. A patterned coil is formed on the lens surface at least in one layer and has a light-passing opening corresponding to the optical axis of the object lens. A light-pervious layer is formed on the lens surface for closing the light-passing opening of the coil.
    Type: Grant
    Filed: July 26, 2000
    Date of Patent: June 29, 2004
    Assignee: Fujitsu Limited
    Inventors: Kazushi Uno, Shingo Hamaguchi, Kyoko Tadaki, Kiyoto Matsui, Goro Kawasaki, Nobuyuki Kanto
  • Patent number: 6717893
    Abstract: An optical pickup assembly includes an optical pickup unit (OPU), a thermally conductive plate, and a flex circuit. The flex circuit is mounted atop the plate. The OPU is also mounted atop the plate through a cutout of the flex circuit. Alternatively, the flex circuit is mounted below the plate and the OPU is mounted atop the plate. The optical pickup assembly further includes an actuator arm. The OPU is mounted on the actuator arm with a portion of the plate contacting the actuator arm.
    Type: Grant
    Filed: October 4, 2000
    Date of Patent: April 6, 2004
    Assignee: DPHI Acquisitions, Inc.
    Inventors: David W. Niss, Thomas E. Berg, Robert D. Freeman, Bernard W. Bell, Jr., Ian R. Redmond, Scott D. Abrahamson
  • Patent number: 6690624
    Abstract: A magnetic lens has a reproducing layer and a magnetic slit. When the leak magnetic field Hlk of a recording magnetic domain on a recording disk exceeds the coercive force He of the magnetic slit, the magnetization in the magnetic slit is inverted into the same direction as that of the magnetization of the recording magnetic domain. Transition occurs from the in-plane magnetization to the perpendicular magnetization in a magnified area of the reproducing layer in which the temperature exceeds the critical temperature Tcr. The upward magnetization in the magnetic slit is transferred thereto. The magnetization information on the recording magnetic domain is reproduced with amplified signal intensity on the basis of the magneto-optical effect by detecting the reflected light beam of the reproducing light beam from the magnified area. A plurality of minute magnetic domains contained in an object can be detected respectively at a high sensitivity in an independent manner.
    Type: Grant
    Filed: July 3, 2002
    Date of Patent: February 10, 2004
    Assignee: Hitachi Maxell, Ltd.
    Inventors: Katsusuke Shimazaki, Yoshitane Tsuburaya
  • Publication number: 20040008591
    Abstract: A magnetic recording device is provided according to the present invention for magnetic recording on a recording medium. The magnetic recording device includes a magnetic pole and a C-aperture structure disposed adjacent the magnetic pole. A focusing element receives light from a light source and focuses the received light onto the C-aperture structure, such that the light incident upon the C-aperture structure and a magnetic flux flowing through the magnetic pole are co-locatable on a recording medium disposed adjacent to the magnetic recording device. The focusing element may include a planar waveguide receiving and focusing the light onto the C-aperture structure.
    Type: Application
    Filed: June 23, 2003
    Publication date: January 15, 2004
    Applicant: Seagate Technology LLC
    Inventors: Earl C. Johns, William A. Challener
  • Publication number: 20040001394
    Abstract: An apparatus for producing a small spot of optical energy comprises a planar waveguide shaped to direct a linearly polarized electromagnetic wave to a focal point within the waveguide, and a metallic pin positioned at the focal point whereby the linearly polarized electromagnetic wave creates surface plasmons on a surface of the pin. The apparatus can further comprise means for phase shifting a portion of the linearly polarized electromagnetic wave. Recording heads comprising a magnetic write pole, a planar waveguide positioned adjacent to the magnetic write pole, the planar waveguide being shaped to direct a linearly polarized electromagnetic wave to a focal point within the waveguide, and a metallic pin positioned at the focal point whereby the linearly polarized electromagnetic wave creates surface plasmons on a surface of the pin, and disc drives that use such recording heads are also disclosed.
    Type: Application
    Filed: March 19, 2003
    Publication date: January 1, 2004
    Applicant: Seagate Technology LLC
    Inventors: William Albert Challener, Christophe Daniel Mihalcea, Tim Rausch
  • Patent number: 6657927
    Abstract: An optical head comprises a laser light source, detectors, a reflecting mirror, a magnetic coil, and a driving circuit which are formed in a monolithic manner on a surface of a substrate. A diffraction grating is formed on the reflecting mirror. A reflected light beam can be divided into those directed to the detectors. Optical paths from the reflecting mirror to the respective detectors are disposed in directions along the substrate. Accordingly, the thickness of the optical head can be made thin. The substrate can be also processed into a slider. The optical head is capable of high speed access and high speed data transfer, in which a miniaturized size and a light weight are realized.
    Type: Grant
    Filed: August 4, 1999
    Date of Patent: December 2, 2003
    Assignee: Hitachi Maxell, Ltd.
    Inventors: Hiroyuki Awano, Hitoshi Watanabe
  • Publication number: 20030185109
    Abstract: An information recording/reproducing apparatus for recording and reproducing information to and from a magneto-optical storage medium that includes a first magnetic layer for recording at least information, a second magnetic layer for regulating a switched connective force, and a third magnetic layer for shifting a magnetic wall of recorded markings for information reproduction. The three layers being stacked on a transparent substrate to make up the storage medium. The information recording/reproducing apparatus includes an optical head and a magnetic head. The optical head has a light source and an objective lens, the light source is configured to emit at least a laser beam with a wavelength of about 780 nm, the objective lens having a numerical aperture of about 0.45 and is configured to focus the laser beam from the light source into a beam spot for emission onto the magneto-optical storage medium. The magnetic head is for applying a recording magnetic field to the magneto-optical storage medium.
    Type: Application
    Filed: April 1, 2003
    Publication date: October 2, 2003
    Applicant: Sony Corporation
    Inventors: Minoru Tobita, Yoshiyuki Teraoka, Tomiji Tanaka, Masato Hattori, Tamotsu Ishii
  • Publication number: 20030184903
    Abstract: A ridge waveguide having a recessed ridge forming an isolated tip at a terminal end of the waveguide's aperture efficiently couples light into a spot adjacent to the tip in a medium below the terminal end of the waveguide which is significantly smaller than the light's wavelength. The waveguide is used to heat a recording medium via the small spot for heat assisted recording or to pattern substrates by photolithography with line width exposures that are significantly smaller than the wavelength of light. The body of the waveguide may also be recessed away from the medium in an area surrounding the waveguide's aperture to further confine the energy emerging from the waveguide to the small spot adjacent the tip in the medium.
    Type: Application
    Filed: March 28, 2003
    Publication date: October 2, 2003
    Applicant: Seagate Technology LLC
    Inventor: William Albert Challener
  • Publication number: 20030128633
    Abstract: A magnetic recording head for use in conjunction with a magnetic recording medium. The magnetic recording head includes a hybrid write pole structure for applying a magnetic write field to the magnetic recording medium. The write pole includes a first layer and a second layer, wherein the first layer has a first saturation magnetic moment and the second layer has a second saturation magnetic moment that is greater than the first saturation magnetic moment. The magnetic recording head also includes a means for heating the magnetic recording medium proximate to where the write pole applies the magnetic write field to the recording medium. A method of heat assisted magnetic recording is also included.
    Type: Application
    Filed: May 29, 2002
    Publication date: July 10, 2003
    Applicant: Seagate Technology LLC
    Inventors: Sharat Batra, Billy W. Crue, William A. Challener
  • Patent number: 6580667
    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: Grant
    Filed: June 4, 2001
    Date of Patent: June 17, 2003
    Assignee: Fujitsu Limited
    Inventor: Masakazu Taguchi
  • Patent number: 6522618
    Abstract: An integrated optical apparatus includes an optically transparent substrate with a light source and a detector mounted adjacent thereto. The substrate includes an optical element in a transmit path from the light source to a remote target. The optical element splits the light into more than one beam. A detector receives beams reflected by the target. All optical elements needed to create the more then one beam, direct the more than one beam onto the target and direct the more than one beam from the target to the detector are on the substrate and/or any structure bonded to the substrate. Preferably, the optical element provides sufficient separation between the more than one beam such that each beam is delivered to a unique respective light detecting element of the detector. The return path from the remote target to the detector may include an optical element for each beam or no optical elements. An additional substrate may be included and bonded to the substrate.
    Type: Grant
    Filed: August 15, 2000
    Date of Patent: February 18, 2003
    Assignee: Digital Optics Corp.
    Inventors: Michael R. Feldman, Alan D. Kathman, W. Hudson Welch
  • Patent number: 6438073
    Abstract: A magnetic lens has a reproducing layer and a magnetic slit. When the leak magnetic field Hlk of a recording magnetic domain on a recording disk exceeds the coercive force Hc of the magnetic slit, the magnetization in the magnetic slit is inverted into the same direction as that of the magnetization of the recording magnetic domain. Transition occurs from the in-plane magnetization to the perpendicular magnetization in a magnified area of the reproducing layer in which the temperature exceeds the critical temperature Tcr. The upward magnetization in the magnetic slit is transferred thereto. The magnetization information on the recording magnetic domain is reproduced with amplified signal intensity on the basis of the magneto-optical effect by detecting the reflected light beam of the reproducing light beam from the magnified area. A plurality of minute magnetic domains contained in an object can be detected respectively at a high sensitivity in an independent manner.
    Type: Grant
    Filed: June 17, 1999
    Date of Patent: August 20, 2002
    Assignee: Hitachi Maxell, Ltd.
    Inventors: Katsusuke Shimazaki, Yoshitane Tsuburaya
  • Publication number: 20020034129
    Abstract: Recording/reproducing information signals to/from a recording medium appropriately even though the clearance from the signal recording surface of the recording medium to an optical head slider becomes significantly small. An optical head slider 10 includes a sliding member 11 which is floated and slides on a recording medium 4 at the time of recording/reproducing signals to/from the recording medium 4, a hemispheric objective lens 12 which is bonded to the sliding member 11, and a magnetic field generating means 16, which is mounted to the bottom of the sliding member 11 which faces the recording medium 4. The sliding member 11 is made of the same material as that of the optical lens 12, and a flat surface of the optical lens 12 is bonded to the top surface of the sliding member 11.
    Type: Application
    Filed: September 18, 2001
    Publication date: March 21, 2002
    Applicant: Sony Corporation
    Inventors: Akio Mishima, Kenjiro Watanabe
  • Publication number: 20020021627
    Abstract: The present invention relates to a recording head for recording information based on an optical magnetic recording system, and has an object of carrying out a high-density recording by reducing the beam diameter of an optical beam irradiated to a recording medium. When an optical beam having a larger diameter than that of the recording head is irradiated, this optical beam is condensed in a light guiding layer. The optical beam is further condensed with a sharp-headed chip. The condensed optical beam is emitted from an emission aperture smaller than the wavelength of the light at the front end of the chip, and irradiated to the recording medium.
    Type: Application
    Filed: September 13, 2001
    Publication date: February 21, 2002
    Applicant: FUJITSU LIMITED
    Inventors: Shinya Hasegawa, Wataru Odajima, Fumihiro Tawa, Nobuhide Aoyama
  • Patent number: RE40371
    Abstract: An optical disc recording/reproduction apparatus for recording and/or reproducing a data by applying a beam from an optical head unit through a substrate onto/from a recording layer of the optical disc through, wherein the substrate of the optical disc is 0.3 mm or below; the optical head unit comprises: an objective lens for converging an incident beam and emitting the beam toward the optical disc; a forward lens for converging the beam introduced through the objective lens and applying the beam to the optical disc; a lens holder where the objective lens and the forward lens are fixed; and an actuator for driving the objective lens and the forward lens as a unitary block and controlling at least focusing, the objective lens and the forward lens having a total numerical aperture of 0.8 or above.
    Type: Grant
    Filed: December 1, 2000
    Date of Patent: June 10, 2008
    Assignee: Sony Corporation
    Inventors: Isao Ichimura, Fumisada Maeda, Kenji Yamamoto, Kiyoshi Ohsato, Toshio Watanabe, Akira Suzuki
  • Patent number: RE38648
    Abstract: A light source for generating light beams, a diffraction grating for splitting the light beam emitted from the light source into at least three light beams, and an objective lens for receiving the reflecting light beams from the recording medium, the magnification of the objective lens being −6.0 to less than −12.0, make up a collimatorless optical system. The reflecting light beams emanating from the objective lens are split by a beam splitter, these split light beams are each split into at least three light beams by a Wollaston prism, and are incident on a photo detecting element. A tracking error signal, a focusing error signal, and a magneto-optical signal are generated using the light beams received by the photo detecting element. The beam splitter and the Wollaston prism may be substituted by a multifunctional Wollaston prism. If the nine split light beams are all received by the photo detecting element, the signals produced by the photo detecting element are large in amplitude.
    Type: Grant
    Filed: April 16, 1998
    Date of Patent: November 9, 2004
    Assignee: TDK Corporation
    Inventors: Kazunori Hirose, Mitsuru Kinouchi