Patents Issued in September 14, 2004
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Patent number: 6791774Abstract: A contact magnetic transfer method forms a pattern of magnetized servo regions in the magnetic recording layer of a rigid perpendicular magnetic recording disk. A master disk or template has a rigid or flexible base with a first film of soft magnetic material on the base and a pattern of islands of soft magnetic material on and extending above the first film and recesses between the islands. The slave disk to be servo patterned is either DC magnetized in a first direction perpendicular to the plane of the recording layer or AC-erased. The slave disk is then placed with its outer layer in proximity to the islands of the master template and a magnetic field is applied in a perpendicular direction to magnetize the regions beneath the islands in the same direction as the applied field. In the regions of the recording layer beneath the recesses of the template the magnetization is reversed from that in the regions beneath the islands.Type: GrantFiled: May 12, 2003Date of Patent: September 14, 2004Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Thomas R. Albrecht, Zvonimir Z. Bandic
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Patent number: 6791775Abstract: The present invention is a method and system to determine a quality of a head in a hard disk drive. The method comprises providing a disk having a at least one side with a plurality of tracks, writing on a predetermined track on the plurality of tracks and reading a profile of the predetermined track to provide a first profile value. The head is then moved to an adjacent track where it writes on the adjacent track. A profile of the predetermined track is then read to provide a second profile value. A quality of the head can then be determined based on the first and second values.Type: GrantFiled: October 15, 2001Date of Patent: September 14, 2004Assignee: Samsung Electronics, Co., Inc.Inventors: Zhaohui Li, Geng Wang, Keung Youn Cho
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Patent number: 6791776Abstract: In order to generate a sampling clock having a higher accuracy, a synchronous signal generating circuit is provided with a phase error detector, detecting a phase error of a read out signal digitized on the basis of FDTS algorithm, and a VCO, controlling an oscillation frequency on the basis of a phase error detected by the phase error detector, to generate a synchronous signal by the VCO. On the basis of the synchronous signal generated by the synchronous signal generating circuit, an ADC digitizes the read out signal. The digitized read out signal is then converted to binary data by a detection circuit.Type: GrantFiled: February 28, 2001Date of Patent: September 14, 2004Assignees: Hitachi, Ltd., Hitachi Video and Information System, Inc.Inventors: Takatoshi Kato, Takushi Nishiya, Hideyuki Yamakawa, Takashi Nara, Nobuaki Nakai, Hiroshi Ide, Shintaro Suzumura, Terumi Takashi
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Patent number: 6791777Abstract: A data discriminating unit includes a data discriminator and a sync signal discriminator. A data sync signal is detected for the bit string discriminated from the output of the sync signal discriminator, and the data is demodulated for the bit string discriminated from the output of the data discriminator, thereby optimizing the signal to a form suitable for discrimination and detection of the data sync signal and demodulation for data reproduction. As a result, the detection performance of the data sync signal can be improved while maintaining the data discrimination performance. A Viterbi decoder is used for discrimination by the data discriminator and the sync signal discriminator for the optimization thereby to optimize the number of states, the number of paths for state transition and the path memory length. A signal having no continuous inversions of the recording data is used as the data sync signal.Type: GrantFiled: February 16, 2001Date of Patent: September 14, 2004Assignee: Hitachi Global Storage Technologies Japan, Ltd.Inventors: Yoshiju Watanabe, Terumi Takashi
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Patent number: 6791778Abstract: An apparatus, method and computer program product for a hard disk drive defect detection system. In one embodiment, a method of detecting defects on the surface of a disk having a plurality of tracks is recited. The method comprises reading, one or more times, the servo bits for a plurality of sectors and determining a burst measure for at least one sector, where the burst measure is a function of the burst signals for the sector. This method further comprises determining a reference value, where the reference value is a function of the burst signals of the plurality of sectors, and comparing the burst measure of at least one sector to the reference value to identify a potential defect. In one embodiment, a sector is mapped as defective where its burst measure differs from the reference value by at least 5 percent.Type: GrantFiled: September 13, 2001Date of Patent: September 14, 2004Assignee: Samsung Electronics Co., Inc.Inventors: Sang Hoon Chu, Jun Seok Shim, Seong Hwon Yu, Soo Il Choi
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Patent number: 6791779Abstract: A disk drive having a connection-blocking device for use with a Serial Advanced Technology Attachment (SATA) power receptacle. The disk drive has a moveable head for writing and reading to and from a disk, a printed circuit board assembly (PCBA) for controlling operations in the disk drive, a Serial Advanced Technology Attachment (SATA) section attached to the PCBA having a SATA power receptacle and a SATA data receptacle, a legacy Integrated Drive Electronics (IDE) power receptacle attached to the PCBA, and a connection-blocking device. The legacy IDE power receptacle is electrically common with the SATA power receptacle. The connection-blocking device is attachable to either one of the SATA power receptacle or the legacy IDE power receptacle, respectively, to prevent redundant power connections within the disk drive.Type: GrantFiled: September 30, 2002Date of Patent: September 14, 2004Assignee: Western Digital Technologies, Inc.Inventors: Dalwinder Singh, Marc B. Goldstone
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Patent number: 6791780Abstract: The present invention is a method and system to optimize a write channel in a hard disk drive. The method comprises providing a disk having a at least one side with a plurality of tracks, and selecting a target track from the plurality of tracks. Data is written at least once on a predetermined plurality of tracks adjacent to either side of the target track and on the target track. Data is also written a predetermined number of times on tracks immediately adjacent to the target track. Data written on the predetermined plurality of tracks adjacent to either side of the target track and on the target track is then read. The process then determines if a number of errors on the tracks is greater than a predetermined criteria, if so, a write current value of the write channel is decreased, otherwise the write current value is increased.Type: GrantFiled: October 15, 2001Date of Patent: September 14, 2004Assignee: Samsung Electronics Co., Inc.Inventors: Hae Jung Lee, Sang Lee, Keung Youn Cho, Ken Bovatsek
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Patent number: 6791781Abstract: A method and apparatus for providing linear position (LPOS) estimations. If valid LPOS data may be detected from the tape, then a first method for LPOS estimation is performed using the Hall effect sensors. If valid LPOS data may not be detected from the tape, then an error recovery procedure (ERP) is invoked so that a second method for LPOS estimation is used to provide accurate LPOS information which is synchronized to a validly detected LPOS from tape within about 1 meter prior to the desired data record.Type: GrantFiled: July 17, 2001Date of Patent: September 14, 2004Assignee: International Business Machines CorporationInventors: Nhan X. Bui, John Alexander Koski, Akimitsu Sasaki, Keisuke Tanaka, Kazuhiro Tsuruta
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Patent number: 6791782Abstract: A method and an apparatus select the operational spindle rotation rate for a disk drive based on measured performance of the head-disk assembly. The position error values are measured and analyzed to generate a position error metric. Based on the value of the position error metric, an operational spindle rotation rate is selected for use when the head-disk assembly is combined with a controller to produce a disk drive.Type: GrantFiled: January 31, 2002Date of Patent: September 14, 2004Assignee: Western Digital Technologies, Inc.Inventors: Raffi Codilian, William D. Johns, Joseph M. Viglione
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Patent number: 6791783Abstract: A magnetic head device including a slider, a resilient supporting member which supports the slider, and piezoelectric elements which are mounted on the resilient supporting member. The piezoelectric elements each include a piezoelectric layer and a pair of electrode layers, a first electrode layer and a second electrode layer. The surface of each second electrode layer and a stationary base end portion and a sliding portion are joined together through an electrically conductive adhesive resin, and both end portions of each piezoelectric element and the stationary base end portion and the sliding portion are joined together through a nonconductive adhesive resin.Type: GrantFiled: March 15, 2002Date of Patent: September 14, 2004Assignee: Alps Electric Co., Ltd.Inventor: Masayoshi Nakagawa
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Patent number: 6791784Abstract: The diffraction-based monitoring techniques described herein can be used, for example, as quality assurance measure in manufacture of magnetic recording media with servo tracking. In one embodiment, the invention presents a system comprising a light source such as a laser that directs light upon a surface of a magnetic recording medium. The magnetic recording medium has two or more physical marks, and the light striking the magnetic recording medium produces a diffraction pattern. A light detector such as a photodiode detects some or all of the diffraction pattern. The physical marks may be servo tracks on the magnetic recording medium, and the detected diffraction pattern is a function of the characteristics of the servo tracks.Type: GrantFiled: March 23, 2001Date of Patent: September 14, 2004Assignee: Imation Corp.Inventor: Jathan D. Edwards
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Patent number: 6791785Abstract: A controller for a disk drive that accesses a look up table having a plurality of thermally characterized values corresponding to a plurality of seek operations. For each seek operation, the corresponding value is added to a register. The controller decrements the register at a rate that is determined using servo interrupts occurring as a result of the rotation of the disk. When the value of the register exceeds a threshold, the controller adjusts the subsequent seek operation so as to inhibit damage to the voice coil as a result of overheating.Type: GrantFiled: February 28, 2001Date of Patent: September 14, 2004Assignee: Western Digital Technologies, Inc.Inventors: Carl R. Messenger, David D. Nguyen
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Patent number: 6791786Abstract: An actuator control system for a two-stage actuator system of a disc drive has a first, or primary, stage actuator consisting of a voice coil motor that positions the head relative to a disc and a microactuator that alters the actuator system without operation of the voice coil motor. A control loop includes a controller responsive to seek commands to operate the voice coil motor, thereby moving the head relative to the disc. An active damping circuit is coupled to the head to operate the microactuator to damp resonance modes of the actuator system.Type: GrantFiled: December 11, 2000Date of Patent: September 14, 2004Assignee: Seagate Technology LLCInventors: JianBo He, Joseph Cheng-Tsu Liu, Kevin Gomez, Tao Zhang
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Patent number: 6791787Abstract: Disclosed is an improvement in a tape guide device having an inclined post and a guide roll rising upright on its base for guiding and directing a length of recording tape to the rotary drum on the deck of a video recorder. The base is made of a synthetic resin material, and has an axle hole made therein for press-fitting the axle of the guide roll. The upper end of the axle hole is tapped, and the axle hole has at least one rib projecting inward from its inner circumference. The axle is threadedly engaged with the upper end of the axle hole, and is press-fitted in the axle hole with the rib or ribs pressed and slightly deformed. Thus, the axle can be positively held in the axle hole of the base, preventing the guide roll to shake in the axle hole, still permitting adjustment of the height of the guide roll. Thanks to such ribs the tight insertion of the axle in the axle hole is assured without the necessity of machining or molding with high precision.Type: GrantFiled: February 19, 2003Date of Patent: September 14, 2004Assignee: Orion Electric Co., Ltd.Inventor: Kouji Azai
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Patent number: 6791788Abstract: A segmented power strip for supplying electrical power to a robotic device for use in a data storage system, the robotic device adapted to move along a guide rail. The power strip includes first and second substantially planar members each having an end and a conductor for making electrical contact with the robotic device. The first and second members are assembled to create a joint where the conductor of the first member is proximate the conductor of the second member such that the robotic device maintains electrical contact with at least one conductor as the robotic device traverses the joint. The ends of the first and second members are adapted to cooperate such that at least one of the first and second members moves laterally relative to the other during assembly thereof. At least one of the first and second members is biased against lateral motion relative to other.Type: GrantFiled: December 27, 2001Date of Patent: September 14, 2004Assignee: Storage Technology CorporationInventors: Gary Gustafson, Timothy C. Ostwald
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Patent number: 6791789Abstract: A tape drive (10) for use with a cartridge (24) having a storage tape (30) that moves along a tape path (32) includes a drive housing (12) defining a drive interior (62), a circuit assembly (42) that generates heat, and a thermal insulator (44). In one embodiment, the thermal insulator (44) is positioned between a portion of the storage tape (30) and the circuit assembly (42). The thermal insulator (44) can be formed from a flexible, plastic material and/or can have a thermal conductivity of less than approximately 50 W/mK to decrease the transfer of heat between the circuit assembly (42) and the storage tape (30). The drive interior (62) can have a first region (64) that includes a portion of the tape path (32), and a second region (66) that includes the circuit assembly (42).Type: GrantFiled: December 12, 2002Date of Patent: September 14, 2004Assignee: Quantum CorporationInventor: Christopher Rathweg
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Patent number: 6791790Abstract: In a hard disk drive, at least one groove is formed in any of the base plate and the cover plate to pump air toward an outer side of the disk. An outer end of the groove is located at a position inwardly separated from an edge of the disk such that an air journal zone of predetermined width is formed along a circumferential direction of the disk between the outer end of the groove and the edge of the disk. The groove is formed in multiple numbers in a circumferential direction of the disk at a predetermined interval and is extended in a radial direction from an inner side of the disk and curved in a direction in which the disk rotates. Thus, vibration of the disk is reduced by a damping operation of air pumped by the groove having a high pressure in the air journal zone.Type: GrantFiled: February 11, 2003Date of Patent: September 14, 2004Assignee: Samsung Electronics Co., Ltd.Inventor: Hong-kwon Lee
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Patent number: 6791791Abstract: An aspect of the invention can be regarded as a disk drive that includes a disk drive base and a spindle motor hub rotatably coupled to the disk drive base. The disk drive further includes a first disk disposed about the spindle motor hub and having a first disk stiffness. The disk drive further includes a second disk disposed about the spindle motor hub and having a second disk stiffness different than the first disk stiffness. According to another aspect of the present invention, the second disk has a second disk thickness different than a first disk thickness. According to another aspect of the present invention, the second disk is formed of a second material having a second material stiffness different than a first material stiffness.Type: GrantFiled: November 30, 2001Date of Patent: September 14, 2004Assignee: Western Digital Technologies, Inc.Inventors: Steven J. Alfred, Raffi Codilian, Serge Hauert, Lin Yang
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Patent number: 6791792Abstract: A magnetic field sensor for sensing an applied magnetic field by utilizing a Hall effect. Used, as a sensor portion, are compound materials such as FeN showing a significant anomalous Hall effect, and materials containing magnetic properties such as a magnetic semiconductor having a zincblende structure and oxide having a perovskite structure. A device structure of the magnetic field sensor is adopted, in which by providing a current terminal to a film and a voltage terminal thereof respectively in a film thickness direction and in an in-plane direction, the magnetic field can be guided into the in-plane direction.Type: GrantFiled: February 19, 2002Date of Patent: September 14, 2004Assignee: Hitachi, Ltd.Inventor: Hiromasa Takahashi
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Patent number: 6791793Abstract: A read/write head and method of making the same, are used in a data storage system, such as a disk drive, for perpendicular magnetic recording of data. The head employs a two-layer pole design with a main pole made of sputtered high moment magnetic material, and an adjunct pole made of electroplated soft magnetic film. The adjunct pole is substantially recessed from the air bearing surface. The present head design significantly enhances the magnetic write field, and substantially reduces side-writing that result in accidental erasure of data in adjacent tracks on the magnetic recording medium.Type: GrantFiled: September 14, 2001Date of Patent: September 14, 2004Assignee: Western Digital (Fremont), Inc.Inventors: Yingjian Chen, Xiaozhong Dang, Francis H. Liu, Kroum Stoev, Hai Jiang, Yugang Wang, Xizeng Shi
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Patent number: 6791794Abstract: By inserting a first antistripping layer comprising a first non-magnetic layer 22 and a first conductive layer 23 between a first magnetic layer 16 and a magnetic separation layer 13, adhesion between the first conductive layer 23 and the magnetic separation layer 13 is improved to prevent the first magnetic layer 16 from stripping. In addition, by inserting a second antistripping layer comprising a second non-magnetic layer 24 and a second conductive layer 25 between a second magnetic layer 21 and a magnetic gap layer 17, adhesion between the second conductive layer 24 and the magnetic gap layer 17 is improved to prevent the second magnetic layer 25 from stripping.Type: GrantFiled: April 1, 2002Date of Patent: September 14, 2004Assignee: NEC CorporationInventors: Hiroaki Honjo, Tsutomu Ishi, Mikiko Saito, Shinsaku Saito, Tamaki Toba, Yoshihino Nonaka, Kazuhiko Hayashi, Nobuyuki Ishiwata
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Patent number: 6791795Abstract: A lower magnetic pole front end layer is formed on a lower magnetic pole main layer, and a lower magnetic pole projection layer, a recording gap layer and an upper magnetic pole front end layer each having substantially the same planar shape are formed on a planar surface of the lower magnetic pole front end layer. Trimming of a lower electrode is not necessary, and track width accuracy can be drastically improved because a resist frame is formed on the planar surface. A length of the upper magnetic pole front end layer from an air bearing surface to a head rear direction is greater than a length of the lower magnetic pole front end layer, and the rear end portion of the lower magnetic pole front end layer substantially defines a gap depth.Type: GrantFiled: August 16, 2002Date of Patent: September 14, 2004Assignee: Hitachi, Ltd.Inventors: Shigekazu Ohtomo, Moriaki Fuyama, Nobuo Yoshida, Hiroshi Fukui
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Patent number: 6791796Abstract: The present invention is a perpendicular writer having an air-bearing surface, a main pole with an extension, and return pole, and a back gap closure intermediate the main pole extension and the return pole. The main pole includes a top magnetic layer and a soft magnetic underlayer separated by a nonmagnetic spacer. The main pole extension is in direct contact with the main pole and recessed from the air-bearing surface. The top magnetic layer forms a trailing edge of the main pole at the ABS and has a magnetic moment greater than that of the soft magnetic underlayer. Further, the top magnetic layer and the soft magnetic underlayer are antiferromagnetically coupled through the thin nonmagnetic spacer. The nonmagnetic spacer has predominantly 111-crystalline texture and promotes reduction of coercivity and grain size along with an increase of anistropy of the top magnetic layer material.Type: GrantFiled: September 27, 2002Date of Patent: September 14, 2004Assignee: Seagate Technology LLCInventors: Alexander Mikhailovich Shukh, Vladyslav Alexandrovich Vaśko, Declan Macken
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Patent number: 6791797Abstract: A magnetic recording medium includes a cylindrical substrate and pores embedded with a magnetic substance that are provided on the outer circumferential surface of the cylindrical substrate and aligned in tracks that are in parallel with one another along the center axis of the cylindrical substrate. The tracks have as their center the center axis of the cylindrical substrate, and form circular orbits defined by planes perpendicular to the center axis. Alternatively, the tracks are in a spiral orbit or in spiral orbits whose center is the center axis of the cylindrical substrate. The pores at intersections of vertical and horizontal rows are aligned in quadrilaterals such as squares, rectangles or rhombi.Type: GrantFiled: March 5, 2003Date of Patent: September 14, 2004Assignee: Canon Kabushiki KaishaInventors: Tsatsuya Saito, Tohru Den
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Patent number: 6791798Abstract: A disk drive suspension and method with a low profile limiter structure located within the vertical extent of the slider, the tongue free and any gap provided by the limiter structure so as to not increase the overall vertical extent of the suspension. The limiter structure has a tab separated on three sides from the suspension beam portion and extending from the beam portion locus toward the suspension tongue portion free end. The tab has a projecting shoulder spaced at a gap from the beam portion. The tongue free end outer terminus has an opening that interfits with the tab in tab shoulder engaging relation to block free end movement away from the locus beyond that permitted by the gap.Type: GrantFiled: November 6, 2001Date of Patent: September 14, 2004Assignee: Magnecomp CorporationInventor: Shijin Mei
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Patent number: 6791799Abstract: A digital data storage apparatus includes a housing defining a housing interior. A rotatable magnetic media and head arrangement for accessing the media are supported in the housing interior. A flexible circuit stiffener defines a stiffener plane and is directly attached to the housing. A ramp arrangement is directly attachable to the flexible circuit stiffener and is configured for receiving the actuator arm in a parked position when so attached. The ramp arrangement includes an indexing arrangement for engaging the housing in a way which positions the ramp arrangement within at least one controlled tolerance relative to the head arrangement. In one feature, the indexing arrangement is resiliently biased against the housing. In a related feature, the housing defines a ramp indexing recess and an indexing pin of the ramp arrangement is resiliently biased into the indexing recess to locate the indexing pin with the controlled tolerance.Type: GrantFiled: December 6, 2002Date of Patent: September 14, 2004Assignee: Convergent Systems Solutions LLCInventor: John F. Fletcher
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Patent number: 6791800Abstract: There is disclosed a disk drive having a magnetic device for applying a direct current magnetic field to the disk 1 by using a disk with a double-layered structure in which a soft magnetic layer is provided on a lower layer of the recording magnetic layer. The magnetic device generates a direct current magnetic field to uniform a magnetic domain state of the soft magnetic layer of the disk. The intensity of the direct current is larger than the anisotropic magnetic field of the soft magnetic layer and is smaller than the coercive force of the recording magnetic layer. As a consequence, the stabilization of the magnetic domain state of the soft magnetic layer of the disk can be realized to make an attempt of decreasing the magnetic noise and establishing stabilization with respect to the disturbance magnetic field.Type: GrantFiled: August 31, 2001Date of Patent: September 14, 2004Assignee: Kabushiki Kaisha ToshibaInventors: Akihiko Takeo, Yoichiro Tanaka
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Patent number: 6791801Abstract: A pivot bearing cartridge for use in a head stack assembly. The cartridge includes a pivot shaft including a central axis, a shaft body and a shaft distal end. The cartridge includes a pivot sleeve disposed about the pivot shaft. The pivot sleeve includes a pivot sleeve annular body and a pivot sleeve closed end disposed adjacent the shaft distal end. The cartridge includes a ball bearing set disposed between and in mechanical communication with the shaft body and the pivot sleeve annular body. The cartridge includes a shaft magnet element attached to the shaft distal end adjacent the pivot sleeve closed end. The shaft magnet element is sized and configured to apply a magnetic force to the pivot sleeve in a direction along the central axis for pre-loading the ball bearing set.Type: GrantFiled: February 28, 2002Date of Patent: September 14, 2004Assignee: Western Digital Technologies, Inc.Inventor: Kamran Oveyssi
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Patent number: 6791802Abstract: The present invention provides a magnetic head device exhibiting a good bonded state of a piezoelectric element and a load beam, and excellent reliability. The magnetic head device includes a slider provided with a reproducing element for detecting a magnetic signal recorded on a recording medium, and a recording element for recording a magnetic signal on the recording medium, an elastic supporting member for supporting the slider, and piezoelectric elements mounted on the elastic supporting member, for distorting the elastic supporting member to change the position of the slider. The piezoelectric element and the elastic supporting member are bonded together with a photo-curing and thermosetting epoxy adhesive resin having a Young's modulus of 1 GPa or more at 25° C., and a glass transition temperature of 90° C. or more.Type: GrantFiled: February 21, 2002Date of Patent: September 14, 2004Assignee: Alps Electric Co., Ltd.Inventors: Mitsuru Watanabe, Hidezi Sato
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Patent number: 6791803Abstract: Provided are a method of magnetic recording and reproducing capable of permitting high density recording on magnetic recording media even under the condition of high data transfer rates and yielding adequate recording and reproduction characteristics when an MR head is used in reproduction, and a magnetic recording medium capable of being used in this magnetic recording and reproducing method. The magnetic recording and reproducing method is a method for reproducing a signal magnetically recorded on a magnetic recording medium with a magnetoresistive (MR) head. The magnetic recording medium comprises a substantially nonmagnetic lower layer and a magnetic layer comprising a hexagonal ferrite ferromagnetic powder and a binder in this order on at least one side of a nonmagnetic support, in which said hexagonal ferrite ferromagnetic powder has a mean plate diameter ranging from 15 to 40 nm and a mean plate thickness ranging from 4 to 15 nm, and said magnetic layer has a coercive force Hc ranging from 143.Type: GrantFiled: August 15, 2002Date of Patent: September 14, 2004Assignee: Fuji Photo Film Co., Ltd.Inventors: Shinji Saito, Nobuo Yamazaki, Hitoshi Noguchi
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Patent number: 6791804Abstract: A magnetoresistive-effect device includes a multilayer film, hard bias layers arranged on both sides of the multilayer film, and electrode layers respectively deposited on the hard bias layers. The electrode layers are formed, extending over the multilayer film. Under the influence of the hard bias layers arranged on both sides of the multilayer, the multilayer film, forming the magnetoresistive-effect device, has, on the end portions thereof, insensitive regions which exhibit no substantial magnetoresistive effect. The insensitive region merely increases a direct current resistance. By extending the electrode layers over the insensitive regions of the multilayer film, a sense current is effectively flown from the electrode layer into the multilayer film. With a junction area between the electrode layer and the multilayer film increased, the direct current resistance is reduced, while the reproduction characteristics of the device are thus improved.Type: GrantFiled: January 6, 2003Date of Patent: September 14, 2004Assignee: Alps Electric Co., Ltd.Inventors: Daigo Aoki, Naoya Hasegawa, Kenji Honda, Yoshihiko Kakihara
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Patent number: 6791805Abstract: A giant magnetoresistive (GMR) stack configured to operate in a current-perpendicular-to-plane (CPP) mode includes a ferromagnetic free layer, at least one synthetic antiferromagnet, at least one nonmagnetic spacer layer, and at least one antiferromagnetic pinning layer. The ferromagnetic free layer has a rotatable magnetic moment. The synthetic antiferromagnet includes a ferromagnetic reference layer having a fixed magnetic moment, a ferromagnetic pinned layer having a fixed magnetic moment, and a coupling layer positioned between the reference layer and the pinned layer, wherein the coupling layer is selected from the group consisting of Cu, Ag and CuAg. The nonmagnetic spacer layer is positioned between the free layer and the synthetic antiferromagnet. The antiferromagnetic pinning layer is positioned adjacent to the synthetic antiferromagnet.Type: GrantFiled: April 1, 2002Date of Patent: September 14, 2004Assignee: Seagate Technology LLCInventors: Olle Gunnar Heinonen, Michael Seigler, Eric W. Singleton
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Patent number: 6791806Abstract: A tunneling magnetoresistive stack configured to operate in a current-perpendicular-to-plane mode has a plurality of layers including a barrier layer. The TMR stack has a plurality of layers including a barrier layer, wherein the barrier layer is comprised of an insulating material selected from a group consisting of HfO, HfAlO, ZrO, TiO, TaO or NdO. The TMR stack exhibits a low resistance-area (RA) product, a stable magnetoresistive (MR) ratio, a lower RA product, a higher breakdown voltage of the TMR stack and enhanced thermal stability.Type: GrantFiled: August 9, 2002Date of Patent: September 14, 2004Assignee: Seagate Technology LLCInventors: Zheng Gao, Sining Mao, Khoung Tran, Janusz Nowak, Jian Chen
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Patent number: 6791807Abstract: A spin-valve magnetic transducing element. In one embodiment, a spin-valve magnetic transducing element is disclosed in which a ferromagnetic tunneling junction film, including first and second ferromagnetic layers and an insulating layer is enclosed between the ferromagnetic layers. A nonmagnetic metal thin film is inserted between the second ferromagnetic layer and the insulating layer, all of which are formed on a substrate.Type: GrantFiled: June 4, 1999Date of Patent: September 14, 2004Assignee: Read-Rite SMI CorporationInventors: Fuminori Hikami, Hideyasu Nagai, Masaki Ueno, Marcos M. Lederman, Hirohiko Kamimura, Masahiko Ando, Kenji Komaki
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Patent number: 6791808Abstract: A clipping device intended for absorbing current peaks from 1 to 10 amperes, formed of a vertical NPN transistor, having an unconnected base, an emitter connected to a terminal on which positive voltage peaks are likely to appear, and a grounded collector, the transistor parameters being set so that it exhibits a negative dynamic resistance.Type: GrantFiled: December 22, 2000Date of Patent: September 14, 2004Assignee: STMicroelectronics S.A.Inventors: Eric Bernier, Robert Pezzani
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Patent number: 6791809Abstract: A charge/discharge protection circuit with n parallel load current switches and a control logic for the latter, which in an over-voltage event disconnects the battery from the charge/discharge terminals through sequentially controlled melting of integrated fusible links, where the control logic in an over-voltage event, simultaneously closes all load current switches, then following sequentially opens a first number of the load current switches, and at the same time closes the switch segments of a short-circuit switch array associated with the respective load current switch, so that the associated fusible links melt sequentially. After the opening of this first number of load current switches the latter closes again and at the same time the remaining number of still closed load current switches opens, as well as continues to sequentially close the remaining switch segments.Type: GrantFiled: November 26, 2002Date of Patent: September 14, 2004Assignee: Dialog Semiconductor GmbHInventor: Axel Pannwitz
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Patent number: 6791810Abstract: There is provided a protection circuit of a field effect transistor having a structure which can be fabricated without restricting a pattern layout and without increasing a process step. A protection circuit of a field effect transistor is a protection circuit of a Schottky gate HFET, and is a circuit in which a forward direction diode and a reverse direction diode are cascade-connected to form a diode unit and two such diode units are connected in series, and a gate line connected to a gate electrode of the HFET is grounded through the protection circuit. The diodes are diodes formed integrally with the Schottky gate HFET which is protected against surge breakdown, and are constituted as Schottky barrier diodes made of an n+-GaAs cap layer formed on a GaAs substrate and Schottky electrodes formed on the n+-GaAs cap layer.Type: GrantFiled: May 22, 2001Date of Patent: September 14, 2004Assignee: Sony CorporationInventors: Mitsuhiro Nakamura, Shinichi Wada
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Patent number: 6791811Abstract: A current sense circuit includes a current sense device and a voltage sense device. The current sense device is positioned to sense a drive current provided to a load by a drive circuit. The voltage sense device is coupled across the current sense device and receives a threshold signal at a first input and provides an output signal on an output whose value is dependent upon whether a sense signal at a second input is above or below the threshold signal. A level of the threshold signal changes in response to a voltage level of a power supply that supplies the drive current to the drive circuit.Type: GrantFiled: October 8, 2003Date of Patent: September 14, 2004Assignee: Gentex CorporationInventors: G. Bruce Poe, Robert R. Turnbull
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Patent number: 6791812Abstract: Surge protector which includes a film pattern (2) formed on a suitable substrate (1) is characterized in that the film pattern (2) essentially consists of narrow lines (2a, 2b, 2c) which extend parallel and adjacent to each other and are electrically in parallel relationship to each other, and bridges (11-24) between the lines. Advantageously, there are three parallel lines. The resistance of the film pattern (2) is trimmed advantageously by cutting (T5, T6, T7, T8, T9, T10) one of the lines (2c) between successive bridges.Type: GrantFiled: December 13, 2000Date of Patent: September 14, 2004Assignee: Nokia Networks OyInventor: Hannu Määttä
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Patent number: 6791813Abstract: The present invention relates to a communication line surge protecting system in which a quarter wavelength open circuit for a wavelength used is disposed in each of a central conductor line 1 and an external conductor line 2 so as to allow a signal with a predetermined communication wavelength to pass therethrough, while blocking signals with frequency components of lighting surge and the like, and in which a ground line is further provided in the central conductor line and a quarter wavelength short circuit for the wavelength used is disposed in each of the ground line and the external conductor line so as to block the signal with the predetermined communication wavelength, while allowing the signals with the frequency components of lighting surge and the like to pass therethrough. The signal of the predetermined wavelength used passes through the communication line and is insulated from the ground.Type: GrantFiled: August 23, 2002Date of Patent: September 14, 2004Assignees: NTT Docomo Kyushu, Inc., Sankosha CorporationInventors: Takashi Shikano, Kiyotaka Ando, Chikashi Okabayashi
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Patent number: 6791814Abstract: An ion generating apparatus 1 has an electric cleaning mechanism 79 for burning out attachment adhered on an ion generating electrode 7 by electric heating. Adhesion of dirt and the like onto the end portion of the electrode where an electron generation field concentrates will considerably ruin the ion generation efficiency. So that burning out of attachment adhered onto the end portion 7a of the ion generating electrode 7 using the electric cleaning mechanism 79 is extremely effective in terms of avoiding such nonconformity. Object of the cleaning will be attained to a sufficient degree if only the dirt adhered onto the sharpened end portion of the electrode 7, which is responsible for the ion generation, is selectively removed, which is also advantageous in simplifying the apparatus since there is no need to excessively raise the electric heating capacity of the electric cleaning mechanism 79.Type: GrantFiled: June 10, 2002Date of Patent: September 14, 2004Assignee: Nihon Pachinko Parts Co., Ltd.Inventors: Yoshiichi Adachi, Yuji Kato
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Patent number: 6791815Abstract: Concentrations of positive and negative ions that are generated in the ambient air at a selected location are controlled in time-varying manner. Apparatus for generating air ions includes controllable high voltage sources and electrodes connected to the sources adapted to generate positive ions and negative ions in ambient air near the electrodes. Control circuitry is coupled to the high voltage sources to control the voltage levels at the electrodes for altering the quantities of positive ions and/or negative ions that are generated in time-varying manner within the ambient air about the electrodes. The control circuitry may control the voltage sources to generate a simulated ion signature of variations in ion concentrations as detected at a selected geographic location.Type: GrantFiled: October 27, 2000Date of Patent: September 14, 2004Assignee: ION SystemsInventor: Martin Graham
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Patent number: 6791816Abstract: Multiple embodiments of a personal defense device each include an electrical stun circuit and electrodes with a structure adapted for use as an impact weapon as well, and further include a radially disposed flashlight or signal light therewith. The electrical circuitry for the stun apparatus may be formed of flexible circuit material with dual circuit paths between each component, for reliability and resistance to damage due to impact forces incurred when the device is used as an impact weapon. A second, normally closed interrupter switch may be provided for the stun circuit, with the user of the present device being required to hold the interrupter switch in order to keep the stun circuitry from operating when the master switch is turned on. The end opposite the handle may include a series of impact ribs with cutting blades removably installable thereon, to produce non-lethal cuts in an assailant during an attack.Type: GrantFiled: February 28, 2003Date of Patent: September 14, 2004Inventor: Kenneth J. Stethem
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Patent number: 6791817Abstract: The invention provides an electro-adhesion device (10) including a base (12) and first (14) and second (16) banks of thin electrically conductive electrodes (18) located apart from each other on a side of the base (12). The electro-adhesion device (10) also includes an insulating cover (20) over the first (14) and second (16) banks so that the outer side of the insulating cover (20) defines an electro-adhesion surface so that, in use, when the electrodes (18) are energized and an object to be attracted is placed adjacent the insulating cover (20), the object is attracted to the insulating cover (20) by a suitably high adhesion force. An outer surface (24) of each of the electrodes (18) has a linear border on one side and a sinusoidal border on an opposite side so that the width of each electrode (18) varies sinusoidally lengthwise along the electrode (18).Type: GrantFiled: December 13, 2002Date of Patent: September 14, 2004Inventors: Herman Allison, Ronald Kevin Fricker, Marthinus Christoffel Smit
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Patent number: 6791818Abstract: An electrode of an electronic device includes plural nickel layers adjacent to each other, and an outer nickel layer contains less phosphorus than an inner nickel layer. The electrode has an increased solder joining strength without having a flexural strength decreased.Type: GrantFiled: June 12, 2003Date of Patent: September 14, 2004Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Koji Shimoyama, Yoshihisa Takase
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Patent number: 6791819Abstract: A capacitor module incorporating a ceramic capacitor having terminal members for reducing stress caused by thermal stress or electrostriction in the ceramic capacitor itself, and a semiconductor device using the capacitor module. The capacitor module and the semiconductor device are designed to have a reduced size and improved reliability.Type: GrantFiled: April 3, 2002Date of Patent: September 14, 2004Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Tohru Kimura, Dai Nakajima, Yuuji Kuramoto
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Patent number: 6791820Abstract: The invention relates to electrical engineering and can be used for developing energy-storing devices. The inventive electrochemical double-layer capacitor makes it possible to develop an operable device having a long service life in addition to high specific energy and power. Said electrochemical double layer capacitor comprises a molten electrolyte (4) provided with a gelling agent.Type: GrantFiled: September 9, 2003Date of Patent: September 14, 2004Assignee: Universal Resources AGInventors: Igor N. Varakin, Alexey B. Stepanov, Victor V. Samitin
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Patent number: 6791821Abstract: An improved tantalum-carbon capacitor employs activated carbon in place of expensive metals to achieve a large surface area, and therefore higher capacitance, but at substantially lower cost than can be achieved using expensive metals to increase surface area. The capacitor includes a tantalum case, a tantalum anode, a dielectric layer on the anode, an electrolyte in contact with the dielectric layer on the anode, a layer of tantalum carbide on an inner surface of the case, and a layer of activated carbon between the layer of tantalum carbide and the electrolyte.Type: GrantFiled: October 16, 2001Date of Patent: September 14, 2004Assignee: Yosemite Investment, Inc.Inventor: Mark T. Monnett
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Patent number: 6791822Abstract: A first capacitor element of a sheet form includes a porous valve metal film, a dielectric layer provided on the porous valve metal film, a solid electrolyte layer provided on the dielectric layer, and a collector layer provided on the solid electrolyte layer. A second capacitor element of a sheet form includes a valve metal film, a porous valve metal body provided on the valve metal film, a dielectric layer provided on the porous valve metal body, a solid electrolyte layer provided on the dielectric layer, and a collector layer provided on the electrolyte layer. The first and second capacitor elements are stacked. The porous valve metal film of the first capacitor element and the valve metal film of the second capacitor element are connected to one external electrode while the collector layers of the first and second capacitor elements are connected to another external electrode, thus providing a solid electrolytic capacitor.Type: GrantFiled: June 6, 2003Date of Patent: September 14, 2004Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Ayumi Kochi, Seiji Takagi, Yuji Mido, Tetsuhiro Korechika
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Patent number: 6791823Abstract: An electrolysis solution for electrolytic capacitors including an aqueous organic solvent consisting of water and a water-compatible organic solvent and 1,6-decane-dicarboxylic acid or salt thereof dissolved therein. The solution further contains one or more additives selected from dinitriles, pivalic acid and salts thereof, diesters, alkylated lactones, cyanoalkanoic esters, monocarbboxylic acids each having a C3-7 alkyl chain and substituted with two C1-4 alkyl groups at the &bgr;-position to the carboxyl group and salts thereof, monocarboxylic acids each having C3-7 alkyl chain and substituted with one ethyl group at the &agr;-position to the carboxyl group and salts thereof, and monocarboxylic acids derived from cyclic saturated compounds each having five or six ring-constituting carbon atoms and salts thereof.Type: GrantFiled: July 15, 2003Date of Patent: September 14, 2004Assignee: UBE Industries, LtdInventors: Koji Abe, Yasuo Matsumori, Motoki Yuguchi, Akikazu Ito, Toshikazu Hamamoto, Yoshihiro Ushigoe