For Adjusting Head Position Patents (Class 360/290)
  • Patent number: 11932215
    Abstract: A method for operating a braking system for a vehicle. A braking request signal characterizing a braking request is generated by actuation of a positioning assemblage of an actuation circuit, and a target brake pressure required in an active circuit is ascertained based on the braking request signal. An actual brake pressure in the active circuit is established in accordance with the target brake pressure, using a pressure generation device, by moving a displacer piston of the pressure generation device using an electric motor of the pressure generation device. If the braking request signal is constant over a predetermined time period, a wheel brake actuated by the active circuit is hydraulically decoupled from the pressure generation device by closing an isolation valve that is disposed in a hydraulic path between the pressure generation device and the wheel brake, and the electric motor is shut off.
    Type: Grant
    Filed: May 25, 2019
    Date of Patent: March 19, 2024
    Assignee: ROBERT BOSCH GMBH
    Inventors: Andreas Krautter, Bertram Foitzik, Timo Haible
  • Patent number: 10762923
    Abstract: A head support mechanism is provided with: a slider with a head element; a slider support plate; a load beam that holds the slider support plate; a fulcrum protrusion that is provided around a front end part of the load beam which supports the slider support plate; drive means that is configured to pivotally move the slider support plate centering on the fulcrum protrusion; and a drive means support portion that is provided to overlap and support the drive means. The drive means support portion has a narrow part and at least one wide part provided on a front end part side and a rear end part side of the load beam with respect to the narrow part. The drive means support portion is disposed at a position overlapping the fulcrum protrusion in a projection plane in a direction perpendicular to a main surface of the slider.
    Type: Grant
    Filed: November 4, 2019
    Date of Patent: September 1, 2020
    Assignee: TDK CORPORATION
    Inventor: Hideki Kuwajima
  • Patent number: 10304483
    Abstract: A slider adhesion system can be practiced in a data storage device with a flexure suspended from a load beam and a slider mounted to a gimbal tongue of the flexure. The slider can be aligned with an aperture of the gimbal tongue and attached to an adhesion feature of the gimbal tongue with an adhesive layer. The adhesion feature may consist of a plurality of cantilevered tabs extending into the aperture of the gimbal tongue.
    Type: Grant
    Filed: December 20, 2017
    Date of Patent: May 28, 2019
    Assignee: Seagate Technology LLC
    Inventors: Christopher Unger, Bradley J. Ver Meer, Ravishankar Ajjanagadde Shivarama
  • Patent number: 9347838
    Abstract: A capacitive shear force sensor and a method for fabricating thereof are provided. The capacitive shear force sensor includes a first electric field shielding layer, a second electric field shielding layer, a driving electrode, a first sensing electrode, a second sensing electrode and a dielectric layer. The second electric field shielding layer is disposed under the first electric field shielding layer. The driving electrode is disposed between the first electric field shielding layer and the second electric field shielding layer. The first and the second sensing electrodes are disposed between the driving electrode and the second electric field shielding layer. The dielectric layer is disposed between the driving electrode and the first sensing electrode, and between the driving electrode and the second sensing electrode. The first sensing electrode and the driving electrode form a first capacitor. The second sensing electrode and the driving electrode form a second capacitor.
    Type: Grant
    Filed: May 17, 2013
    Date of Patent: May 24, 2016
    Assignee: Industrial Technology Research Institute
    Inventors: Sheng-Jui Chen, Gwo-Jen Wu, Chung-Lin Wu, Jian-Lin Huang
  • Patent number: 9296188
    Abstract: Various embodiments concern a method of attaching a microactuator to a flexure, depositing a wet mass of structural adhesive on the flexure, mounting the microactuator on the wet mass of structural adhesive, partially curing the mass of structural adhesive through a first application of curing energy, and depositing a mass of conductive adhesive on the flexure. The mass of conductive adhesive is deposited in contact with the mass of structural adhesive. The state of partial curing of the structural adhesive prevents the conductive adhesive from wicking between the flexure and the underside of the microactuator and displacing the structural adhesive which may otherwise result in shorting to a stainless steel layer of the flexure. The method further comprises fully curing the mass of structural adhesive and the conductive adhesive through a second application of curing energy.
    Type: Grant
    Filed: February 17, 2015
    Date of Patent: March 29, 2016
    Assignee: Hutchinson Technology Incorporated
    Inventors: Scott J. Cray, John L. Schumann, Trent A. Johnson, Luke E. Rose
  • Publication number: 20150124355
    Abstract: Example embodiments include an apparatus that has a piezoelectric contact sensor. The piezoelectric contact sensor includes a semiconductor device having a semiconductor material that defines a channel through which current can flow. The piezoelectric contact sensor also includes a piezoelectric element coupled to the semiconductor material. The semiconductor material is configured to modulate the current channel in response to compressive stress waves at the contact sensor. Other example embodiments include an apparatus that has a slider having an air-bearing surface, a write head integral to the slider, and a piezoelectric contact sensor that includes a semiconductor device and a piezoelectric element.
    Type: Application
    Filed: November 1, 2013
    Publication date: May 7, 2015
    Applicant: Seagate Technology LLC
    Inventors: David J. Ellison, Michael Christopher Kautzky, Jorge Hanchi
  • Publication number: 20150116866
    Abstract: A rotary actuator for positioning a recording head in a data storage mechanism and that includes first and second cylindrical subassemblies separated by an air gap. One of the subassemblies includes a magnetically conductive core with an electrically conductive coil wrapped thereover to enable first and second current flow directions in the circuit. The other of the subassemblies includes a magnetically conductive core and at least one magnet secured thereto. Transmission of an electric current through the electrically conductive coil induces rotation of one of the subassemblies relative to the other of the subassemblies to rotate the recording head about an axis that is perpendicular to recording media on the recording head. The disclosed rotary actuator facilitates quick and accurate recording head position changes due to low inertia of the rotating subassembly as well as reduced inductance and symmetrical mass distribution of the actuator.
    Type: Application
    Filed: October 31, 2013
    Publication date: April 30, 2015
    Applicant: Oracle International Corporation
    Inventors: Darryl Wayne Yeakley, Frank A. Goodknight, Steven G. Suttle
  • Patent number: 8400891
    Abstract: An apparatus includes a read/write head disposed on a slider, a control circuit disposed on the slider, and an adjustable delay line disposed on the slider. The adjustable delay line delays transmission of aligned write data to the read/write head by an adjustable delay. The adjustable delay is controlled by the control circuit a function of read synchronization data provided by the read/write head.
    Type: Grant
    Filed: June 26, 2009
    Date of Patent: March 19, 2013
    Assignee: Seagate Technology LLC
    Inventor: Mark Anthony Gubbins
  • Publication number: 20120243127
    Abstract: According to one embodiment, a magnetic head includes a reproducing section. The reproducing section detects a medium magnetic field recorded in a magnetic recording medium. The reproducing section includes a stacked film and a magnetic field application unit. The stacked film includes a first magnetization layer and a second magnetization layer. The first magnetization layer has a perpendicular magnetic anisotropy. A magnetization of the first magnetization layer being is fixed. The second magnetization layer is stacked with the first magnetization layer and oscillates. The magnetic field application unit is stacked with the stacked film and applies a bias magnetic field having a component along the first axis to the stacked film. A resistance of the stacked film changes in accordance with the medium magnetic field when a current not less than a value at which the second magnetization layer oscillates is passed.
    Type: Application
    Filed: September 22, 2011
    Publication date: September 27, 2012
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hitoshi IWASAKI, Masayuki Takagishi, Kenichiro Yamada, Susumu Hashimoto, Yusuke Tomoda
  • Patent number: 8189300
    Abstract: A capacitive transducer of multi-layer construction includes at least one rotor plate supported by flexible springs, A number of improvements are disclosed including a hollow rotor plate structure for reduced moving mass, buckling resistant features for the springs, improved spring anchor joint design for reduced creep and hysteresis, and material selection and matching for reduced thermal sensitivity. one embodiment allows measurement of force and/or displacement in multiple directions.
    Type: Grant
    Filed: January 3, 2011
    Date of Patent: May 29, 2012
    Inventor: Wayne Allen Bonin
  • Patent number: 8094415
    Abstract: A suspension is provided with a base plate, load beam, and flexure. The base plate includes a boss portion, a first region situated on a side closer to a slider with respect to a center of the boss portion, and a second region situated on a side more remote from the slider. A pair of first projections are formed in the first region. A pair of second projections are formed in the second region. The projections project in the thickness direction of the base plate. The boss portion is inserted into a hole in an actuator arm, and the projections contact a suspension support portion of the actuator arm. The boss portion is pressurized from inside to be enlarged, whereby the base plate is fixed to the inner peripheral surface of the hole of the actuator arm.
    Type: Grant
    Filed: April 7, 2009
    Date of Patent: January 10, 2012
    Assignee: NHK Spring Co., Ltd.
    Inventors: Masaki Yokota, Akira Nojima
  • Patent number: 7894163
    Abstract: Laser beam irradiation areas are provided in a load curve portion and an angle adjustment portion of a suspension. The laser beam irradiation areas are oriented in a direction in which the suspension is to be bent. A laser beam having a predetermined length and a predetermined shape is irradiated onto each laser beam irradiation area.
    Type: Grant
    Filed: January 13, 2009
    Date of Patent: February 22, 2011
    Assignee: NHK Spring Co., Ltd.
    Inventors: Masaru Inoue, Hiroshi Kawamata, Hironori Tanaka
  • Publication number: 20100271735
    Abstract: A microactuator assembly for a hard disk drive head suspension has an expandable base of stainless steel sheet material defining a negative lead affixed to the negative electrode on the bottom surface of a piezoelectric element, and a piece of stainless steel sheet material defining a positive lead attached to the positive electrode on the top surface of the piezoelectric element. The leads may be affixed directly to the piezoelectric element via conductive adhesive. The microactuator assembly can be assembled separately, and then laser welded into place on a suspension. A bond pad made of stainless steel sheet material extends from the flexible circuit, is electrically connected to the microactuator driving voltage conductor within the flexible circuit through a via, and is electrically isolated from the suspension substrate by an insulating film. The microactuator unit positive lead is mechanically and electrically connected to the bond pad via laser welding.
    Type: Application
    Filed: April 24, 2009
    Publication date: October 28, 2010
    Applicant: Magnecomp Corporation
    Inventor: Christopher Schreiber
  • Publication number: 20100165515
    Abstract: A wiring connecting structure for a piezoelectric element is capable of performing wiring to the piezoelectric element without deteriorating the quality and reliability of the piezoelectric element. The piezoelectric element is arranged between a base and head of an object, to minutely move the head in a sway direction according to deformation that occurs on the piezoelectric element in response to a voltage applied from a terminal to an electrode of the piezoelectric element. The wiring connecting structure includes first and second liquid stoppers arranged between the terminal and the electrode, the second liquid stopper being arranged outside the first liquid stopper. The wiring connecting structure also includes an adhesive part to connect the electrode to the terminal. The adhesive part has a conductive adhesive part defined by the first liquid stopper and a sealing adhesive part defined by the second liquid stopper. The sealing adhesive part seals the first liquid stopper and conductive adhesive part.
    Type: Application
    Filed: December 21, 2009
    Publication date: July 1, 2010
    Applicant: NHK SPRING CO., LTD.
    Inventor: Toshiki ANDO
  • Publication number: 20100128399
    Abstract: A hard disk drive that determines a flying height from a ratio of a first harmonic transfer function and a third harmonic transfer function. The transfer functions can be determined from a response to an impulse function. The impulse function (also known as an impulse response) can be a playback waveform de-convolved by channel data sequence. Any change in the ratio of the first and third harmonic transfer functions corresponds to a change in the flying height. The disk drive may utilize the transfer function ratios in a feedback routine to control the flying height.
    Type: Application
    Filed: November 25, 2008
    Publication date: May 27, 2010
    Inventors: Carl Xiaodong Che, Yawshing Tang, Haejung Lee
  • Publication number: 20100002332
    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: Application
    Filed: May 11, 2009
    Publication date: January 7, 2010
    Inventors: Matthew P. Dugas, Jeffrey A. Wallhoff
  • Publication number: 20090262463
    Abstract: A suspension is provided with a base plate, load beam, and flexure. The base plate includes a boss portion, a first region situated on a side closer to a slider with respect to a center of the boss portion, and a second region situated on a side more remote from the slider. A pair of first projections are formed in the first region. A pair of second projections are formed in the second region. The projections project in the thickness direction of the base plate. The boss portion is inserted into a hole in an actuator arm, and the projections contact a suspension support portion of the actuator arm. The boss portion is pressurized from inside to be enlarged, whereby the base plate is fixed to the inner peripheral surface of the hole of the actuator arm.
    Type: Application
    Filed: April 7, 2009
    Publication date: October 22, 2009
    Applicant: NHK Spring Co., Ltd.
    Inventors: Masaki Yokota, Akira Nojima
  • Publication number: 20090251826
    Abstract: Components and assemblies for a hard disk drive (HDD) with a recessed actuator joint are described. A rotary actuator hub assembly comprises a shaft having a flange, and a pivot seat on which the flange is seated when the shaft is fastened to an HDD chassis. According to an embodiment, the pivot seat has at least one “contact-reducing feature” recessed from the surface of the pivot seat at which the seat contacts the flange. A purpose of the contact-reducing feature(s) of the pivot seat is to weaken the joint between the actuator hub assembly and the chassis, thereby mechanically loosening the rotary actuator assembly from the chassis. Consequently, movements to and vibrations from the chassis are less likely to be transmitted to the rotary actuator assembly and, ultimately, to the HDD read/write head(s).
    Type: Application
    Filed: April 7, 2008
    Publication date: October 8, 2009
    Inventors: Takaaki Deguchi, Jr-Yi Shen, Kunihiro Shida, Hitoshi Shindo
  • Publication number: 20090231761
    Abstract: A head suspension assembly includes a head suspension, a load beam having a protrusion, a flexure attached to a surface of the head suspension at a back surface of the flexure and a support plate defined on the flexure. A head slider is secured to the support plate. The support plate and head slider are secured to the load beam over the protrusion. The support plate extends outward from a contour of the head slider, and has at least two openings corresponding to desired locations of corners of the head slider, and a window formed in the head suspension behind the flexure, so that the head slider can be accurately aligned with respect to the openings when the head slider is adhered to the support plate.
    Type: Application
    Filed: October 7, 2008
    Publication date: September 17, 2009
    Applicant: FUJITSU LIMITED
    Inventor: Kaoru Abiko
  • Publication number: 20080186633
    Abstract: In a method and apparatus for testing a head-gimbal assembly (HGA), a HGA is placed in contact with force transducers mounted on a rotational stage. The force transducers are adjusted to position the transducers around a rotational center of the rotational stage. The rotational stage is rotated, and the torque and variations in torque exerted by the HGA on the force transducers during rotation are measured.
    Type: Application
    Filed: February 7, 2007
    Publication date: August 7, 2008
    Inventors: Manuel A. Hernandez, Yen Fu, Ellis T. Cha
  • Publication number: 20080174920
    Abstract: The invention provides a giant magneto-resistive effect device (CPP-GMR device) having a CPP (current perpendicular to plane) structure comprising a spacer layer, and a fixed magnetized layer and a free layer stacked one upon another with said spacer layer interleaved between them, with a sense current applied in a stacking direction, wherein the spacer layer comprises a first and a second nonmagnetic metal layer, each formed of a nonmagnetic metal material, and a semiconductor oxide layer interleaved between the first and the second nonmagnetic metal layer, wherein the semiconductor oxide layer that forms a part of the spacer layer is made of indium oxide (In2O3), or the semiconductor oxide layer contains indium oxide (In2O3) as its main component, and an oxide containing a tetravalent cation of SnO2 is contained in the indium oxide that is the main component.
    Type: Application
    Filed: January 24, 2007
    Publication date: July 24, 2008
    Applicant: TDK CORPORATION
    Inventors: Shinji Hara, Kei Hirata, Koji Shimazawa, Yoshihiro Tsuchiya, Tomohito Mizuno
  • Publication number: 20070211389
    Abstract: An actuator includes a piezoelectric bimorph including a pair of piezoelectric elements and an intermediate electrode provided between the piezoelectric elements, a conductive fastening member for fastening fixed ends of the piezoelectric elements to a base having a ground potential, and a contact member to which a predetermined voltage is applied. The contact member is in contact with the intermediate electrode.
    Type: Application
    Filed: March 7, 2007
    Publication date: September 13, 2007
    Inventor: Takayuki Abe
  • Patent number: 6747267
    Abstract: A static attitude measurement device measures the static attitude of a target, such as a head suspension assembly or component, and reduces the possibility of measurement errors due to stray spots and internal reflections. The device includes a light source for producing a light beam, a beam splitter for directing the light beam toward the target from which a reflected beam is returned, a detector for detecting the reflected beam at a predetermined polarization state and a polarization component for producing the predetermined polarization state in the reflected beam, the polarization component positioned between the beam splitter and the target. The polarization component preferably is a quarter-wave plate to produce a reflected beam that is orthogonally polarized with respect to the incident beam. In addition, the directional optics preferably include a polarizer positioned between before the beam splitter to reduce reflection off of the light source.
    Type: Grant
    Filed: June 25, 2001
    Date of Patent: June 8, 2004
    Assignee: Hutchinson Technology Incorporated
    Inventor: Senthil Balasubramaniam
  • Publication number: 20040017639
    Abstract: The present invention provides a magnetic tunnel junction memory element comprising two pinned ferromagnetic layers having magnetic orientations pointing in opposite directions and a sense layer arranged between the two pinned ferromagnetic layers and separated from each by a nonmagnetic tunnel barrier layer. The invention also provides methods of fabricating magnetic tunnel junction memory elements as well as magnetoresistive memory devices and processor systems comprising such memory elements.
    Type: Application
    Filed: July 23, 2002
    Publication date: January 29, 2004
    Inventor: James G. Deak
  • Patent number: 6646436
    Abstract: The support that bears and positions the head in a head holding apparatus is further supported by a heat-compensating member, so that when the support is expanded by the heat source of the head holding apparatus, the heat-compensating member expands in the direction opposite to the direction of expansion of the support. Moreover, supplying of heat to the support and heat-compensating member is further alleviated by insulating said heat source with an insulating material. The amount of displacement of the recording element per unit of time with exposure to heat is controlled by the above-mentioned structure and effects.
    Type: Grant
    Filed: April 15, 2002
    Date of Patent: November 11, 2003
    Assignee: Agilent Technologies, Inc.
    Inventors: Takahisa Mihara, Toshiki Kita
  • Patent number: 6566832
    Abstract: An apparatus for parking a read/write head during power interruptions and methods of operating the same result in a hard disk drive apparatus that reduces the time to steady state the operating hard disk drive. The apparatus for reducing the time to steady state the operating disk drive having an actuator arm coupled to a voice coil for latching the actuator arm when power is interrupted comprises a Y-winding spindle motor having a first winding, a second winding, and a third-winding, and a spindle motor controller coupled to the Y-winding spindle motor configured to dynamically short the first winding and the second windings to produce a retarding force against the Y-winding motor and to direct power produced by the third winding in series with the first two windings in parallel to the voice coil for moving the actuator arm to a latched position and to maintain sufficient power to the spindle motor to provide greater operating range (headroom).
    Type: Grant
    Filed: May 4, 2001
    Date of Patent: May 20, 2003
    Assignee: Maxtor Corporation
    Inventor: Mehran Ataee
  • Patent number: 6496320
    Abstract: Apparatus and method for attenuating effects of externally generated vibration applied along multiple axes of a disc drive. The disc drive includes a disc with a recording surface, a read/write head and a servo circuit which detects and corrects head position error. The servo circuit determines a plant estimate indicative of transfer function response of the disc drive while the disc drive is operated off-line. A sensor network concurrently generates a plurality of acceleration signals each along a different axis of the disc drive and indicative of a different component of the externally generated vibration applied along the corresponding axis. An adaptive filter network adaptively filters the acceleration signals to generate a compensation signal. The compensation signal is fed forward to the servo circuit to remove the effects of the externally generated vibration.
    Type: Grant
    Filed: September 15, 2000
    Date of Patent: December 17, 2002
    Assignee: Seagate Technology LLC
    Inventor: Zhiqiang Liu
  • Patent number: 6442005
    Abstract: A light diffusion preventing structure, suitable for use in vehicles, is provided on a structural member having a hole for passing light from a light source through the structural member and onto a target area. The hole has a three-dimensional shape that has a first opening located near the light source and a second opening located on the opposite side with an inner peripheral surface running between. Both the edge of the second opening and the inner peripheral surface are located completely outside a zone defined by projecting imaginary straight lines from the point light source through the first opening. A second set of imaginary straight lines running between the edge the first opening and the opposite edge of the second opening define at least one crossing angle, the measure of which should preferably not exceed 160 degrees.
    Type: Grant
    Filed: May 30, 2001
    Date of Patent: August 27, 2002
    Assignee: Toyoda Gosei Co., Ltd.
    Inventors: Tadaoki Ichikawa, Hiroshi Ito, Kazushi Noda
  • Publication number: 20020041472
    Abstract: A method of handling multiple resonance frequencies in a disc drive includes monitoring a position error signal (PES) for an actuator arm, generating a plurality of feedforward compensation signals from the PES using a plurality of bandpass filters, and applying the compensation signals to a servo control signal. Each filter has a center frequency that is set to a problematic resonance frequency. The method may also include identifying the problematic frequencies by, for example, commanding a movement of the actuator arm, collecting data points for the PES that are associated with the movement, and performing a digital fourier transform of the data points to identify resonant frequencies. Other methods of identifying problematic frequencies include analyzing PES zero-crossing data, or using principal component analysis.
    Type: Application
    Filed: April 5, 2001
    Publication date: April 11, 2002
    Inventors: MingZhong Ding, YangQuan Chen, LeeLing Tan, Wing Kong Chiang, KianKeong Ooi, BengWee Quak
  • Patent number: 6262868
    Abstract: A rotary microactuator includes a stationary structure formed on a substrate, a movable structure, and at least a pair of wires connected to the movable structure that conduct a signal associated with the movable structure. Each wire of the pair of wires has a first end that is connected in a cantilever manner to the substrate and a second end that is connected to the movable structure. The wires each have a serpentine shape between the first end and the second end, a predetermined spring stiffness, and a predetermined electrical characteristic. The microactuator also includes a magnetic head slider that is attached to the movable structure, and at least another pair of wires conducting a signal associated with a magnetic head of the slider. Each of the another pair of wires has a first end that is connected in a cantilever manner to the substrate and a second end that is connected to the movable structure.
    Type: Grant
    Filed: December 30, 1997
    Date of Patent: July 17, 2001
    Assignee: International Business Machines Corporation
    Inventors: Satya Prakash Arya, Long-Sheng Fan, Toshiki Hirano, Tzong-Shii Pan, Wing Chun Shum, Timothy Clark Reiley
  • Patent number: 6215629
    Abstract: A dual-stage actuation assembly for a disc drive includes a movable actuator arm and a load beam connected to the actuator arm. A microactuator is attached to the load beam, and includes a first bending motor, a second bending motor and a slider support structure supporting a slider over the disc. The slider support structure is attached between the first and second bending motors. The first and second bending motors are responsive to control signals to translationally move the slider support structure with respect to the load beam, to finely position a transducing head carried by the slider over a selected track of the disc.
    Type: Grant
    Filed: April 9, 1999
    Date of Patent: April 10, 2001
    Assignee: Seagate Technology LLC
    Inventors: Rishi Kant, Frederick Mark Stefansky
  • Patent number: 6137655
    Abstract: A cassette adaptor is disclosed, in which a head holder unit comprises a head holder for holding a magnetic head and a dummy tape frame having dummy tape members, and pins of the dummy tape frame are inserted into holes of the head holder thereby to fasten each other. When a cassette holder is inserted into the cassette tape reproduction apparatus, a tape guide of the cassette tape reproduction apparatus and the dummy tape members engage with each other, and the magnetic head moves to a position in opposed relationship with the reproduction head of the cassette tape reproduction apparatus in response to this engagement.
    Type: Grant
    Filed: June 12, 1998
    Date of Patent: October 24, 2000
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Atsushi Hojo, Hiroshi Yoshiya
  • Patent number: 6111728
    Abstract: A device for mounting a head support (12), which carries a magnetic head (13) at its front, on a head disc (15). The head support (12) is mounted in a separate housing (10) and the housing (10) is secured to the head disc (15) in order to improve the reliability.
    Type: Grant
    Filed: April 4, 1995
    Date of Patent: August 29, 2000
    Assignee: U.S. Philips Corporation
    Inventor: Werner Maack