Signal Switching Patents (Class 360/61)
  • Patent number: 10580450
    Abstract: An apparatus, according to one embodiment, includes a module having a tape bearing surface, an array of magnetic transducers, and a channel in the tape bearing surface. The channel has a longitudinal axis oriented about parallel to a longitudinal axis of the array of magnetic transducers for inducing tenting of a moving magnetic recording tape above the array of magnetic transducers. Moreover, the channel has a shape with a middle section of similar recession therealong between straight opposite ends.
    Type: Grant
    Filed: September 13, 2018
    Date of Patent: March 3, 2020
    Assignee: International Business Machines Corporation
    Inventors: Robert G. Biskeborn, Calvin S. Lo
  • Patent number: 10417336
    Abstract: The illustrative embodiments described herein provide systems and methods for notifying a user when a set of characters are identified in a media file. In one embodiment, a method includes receiving a set of characters inputted by the user of a computing device, playing the media file, transcribing the media file to form a transcription, and determining whether the transcription of the media file includes the set of characters. The method also includes initiating a notification prompt on a graphical user interface of the computing device in response to determining that the media file includes the set of characters.
    Type: Grant
    Filed: July 5, 2016
    Date of Patent: September 17, 2019
    Assignee: OPEN INVENTION NETWORK LLC
    Inventor: Margarita Khafizova
  • Patent number: 9954500
    Abstract: A method includes, in at least one aspect, receiving, at both an input node of a first input stage and in input node of a second input stage, a single-ended voltage signal; providing, by at least one of the first input stage or the second input stage, inductive degeneration to the single-ended voltage signal; converting an output from the first input stage into a first single-ended current signal; converting an output from the second input stage into a second single-ended current signal; and outputting, by an output stage, a differential output including the first single-ended current signal and the second single-ended current signal.
    Type: Grant
    Filed: April 9, 2014
    Date of Patent: April 24, 2018
    Assignee: Marvell World Trade Ltd.
    Inventor: Paolo Rossi
  • Patent number: 9613642
    Abstract: A read/write head includes two or more first transducers of a first type, the first type selected from a magnetic read transducer and a magnetic write transducer. The read/write head includes one or more switching elements coupled to the two or more first transducers. The switching elements are configured to, in response to a control signal, couple a selected one of the two or more first transducers to a preamplifier circuit and decouple others of the two or more first transducers from the preamplifier circuit.
    Type: Grant
    Filed: February 29, 2016
    Date of Patent: April 4, 2017
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Mehmet Fatih Erden, Christopher Anthony Markey, Jon D. Trantham
  • Patent number: 9576597
    Abstract: Implementations described and claimed herein includes a method comprising selecting a zone of one or more tracks on a disk drive having a plurality of magnetic sensors on a transducer head, determining a performance matrix related to the selected track zone, and selecting a first subset and a second subset of the plurality of magnetic sensors based on the determined performance matrix, wherein only the first subset of the plurality of magnetic sensors are used for data recovery in the selected track zone, and the second subset of the plurality of magnetic sensors are used for servo recovery.
    Type: Grant
    Filed: March 12, 2015
    Date of Patent: February 21, 2017
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Jon Trantham, Puskal Pokharel
  • Patent number: 9386256
    Abstract: The illustrative embodiments described herein provide systems and methods for notifying a user when a set of characters are identified in a media file. In one embodiment, a method includes receiving a set of characters inputted by the user of a computing device, playing the media file, transcribing the media file to form a transcription, and determining whether the transcription of the media file includes the set of characters. The method also includes initiating a notification prompt on a graphical user interface of the computing device in response to determining that the media file includes the set of characters.
    Type: Grant
    Filed: April 30, 2010
    Date of Patent: July 5, 2016
    Assignee: Open Invention Network LLC
    Inventor: Margarita Khafizova
  • Patent number: 9290470
    Abstract: The present invention relates to preparation of epoxy karanja oil, epoxy karanja fatty acid methyl esters and their acylated derivatives. Accordingly karanja oil and karanja fatty acid methyl esters were epoxidized using performic acid method. Karanja oil and its fatty acid methyl esters were also hydroxylated to prepare their acyloxy derivatives (C3, C4 & C6). Both the epoxy and acyloxy derivatives of karanja oil and its methyl esters were characterized by 1H NMR and IR studies. The products were evaluated for acid value (A.V.), hydroxyl value (H. V.), iodine value (I. V.), viscosity, viscosity index (V.I.), pour point, flash point and copper strip corrosion and lubricant properties like oxidation stability, air release value, evaporation loss, rust prevention characteristics, hydrolytic stability, foam stability and load carrying capacity and found to be potential base stocks for hydraulic, metal working fluids and other industrial fluids.
    Type: Grant
    Filed: July 9, 2013
    Date of Patent: March 22, 2016
    Assignee: COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCH
    Inventors: Venkata P. Korlipara, Sri Lakshmi K. Mallampalli, Saravanan Krishnasamy, Badari N. P. Rachapudi
  • Patent number: 9276529
    Abstract: An operational amplifier includes three transconductance stages (TSs) each having a differential input and a differential output, a first and second resistor coupled between the differential output of the first TS and the differential input of the first TS, a third and fourth resistor coupled between the differential output of the third TS and the differential input of the first TS, a first and second capacitor coupled between the differential output of the third TS and the differential input of the third TS, wherein the first, second, and third TSs each include a differential input amplifier coupled to the differential input of the respective TS, a differential output amplifier coupled to the differential output of the respective TS, and a plurality of Schottky diodes coupled between the differential input amplifier and the differential output amplifier for voltage level shifting.
    Type: Grant
    Filed: October 3, 2014
    Date of Patent: March 1, 2016
    Assignee: HRL Laboratories, LLC
    Inventors: David F. Brown, Miroslav Micovic, Ara K. Kurdoghlian, Alexandros Margomenos
  • Patent number: 9263072
    Abstract: In one general embodiment, an apparatus includes an inner module comprising an array of first transducers of a first type; and first and second outer modules flanking the inner module. Each outer module includes an array of second transducers of a second type that is different than the first type. Each of the second transducers in each array of second transducers being aligned with a corresponding one of the first transducers in a direction generally parallel to a path of tape travel thereacross. A number of active second transducers in each outer module is less than a number of active first transducers in the inner module.
    Type: Grant
    Filed: February 25, 2015
    Date of Patent: February 16, 2016
    Assignee: International Business Machines Corporation
    Inventor: Peter Vandersalm Koeppe
  • Patent number: 9099125
    Abstract: A two-dimensional magnetic recording (TDMR) multi-sensor read head has three stacked sensors separated by magnetic shields. The lower sensor is the primary sensor that is always aligned with the target track. The middle sensor is spaced laterally from the lower sensor a distance substantially equal to the track pitch (TP). The upper sensor is aligned with the lower sensor. The spacing D between the lower and upper sensors is selected to be related to TP and a maximum skew angle, where the skew angle is the angle between a line orthogonal to the sensor and the data track that varies with radial position of the head. The read head is connected to circuitry that selects two of the three sensors to be the active sensors depending on the radial position of the head and thus the skew angle of the head.
    Type: Grant
    Filed: October 14, 2014
    Date of Patent: August 4, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: Masashi Hattori, Kenichi Meguro, Kouichi Nishioka, Takashi Wagatsuma, Nobuo Yoshida
  • Patent number: 9001448
    Abstract: Disk drive pre-amplifier output stage circuitry is presented including a high pass input filter for removing DC offsets from differential read data signals and providing an input to AB drivers of the output stage, in which an offset test circuit selectively drives the high pass filter output nodes according to the offset at the filter input to facilitate measurement of the preceding circuit offset at the driver output terminals, and a common mode regulator circuit regulates common mode voltages at the first and second driver output nodes to a predetermined value in read and write modes.
    Type: Grant
    Filed: July 30, 2013
    Date of Patent: April 7, 2015
    Assignee: Texas Instruments Incorporated
    Inventor: Douglas Warren Dean
  • Patent number: 8982496
    Abstract: According to one embodiment, switching takes place between a first control in which a first read head is assigned as a master head for reading data from a magnetic disk on which a sequential write direction is reversed at a switching position where a skew angle of a write head becomes 0 and between an outer periphery and an inner periphery in shingled write recording, and a second read head is assigned as a slave head for reducing inter-track interference during reading of the data and noise by virtue of an effect of waveform averaging with respect to the master head, and a second control in which the second read head is assigned as the master head and the first read head is assigned as the slave head.
    Type: Grant
    Filed: July 24, 2014
    Date of Patent: March 17, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Nobuhiro Maeto, Kohsuke Harada
  • Patent number: 8982495
    Abstract: An apparatus according to one embodiment includes a plurality of modules configured to at least read data stored on a magnetic recording tape, each of the modules having an array of readers. One module is configured to read data on a magnetic recording tape which none of the other modules can read. An apparatus according to another embodiment includes a first module configured to at least read data stored on a magnetic recording tape in a first range of formats, and at least a second module configured to at least read data stored on a magnetic recording tape in at least a second range of formats. The first range of formats does not include a format that is in the second range of formats. All of the modules are aligned along a tape travel direction.
    Type: Grant
    Filed: July 9, 2013
    Date of Patent: March 17, 2015
    Assignee: International Business Machines Corporation
    Inventors: Robert G. Biskeborn, Gary M. Decad, Jason Liang
  • Patent number: 8943721
    Abstract: This invention is a huggable picture frame in the form of a person or doll, with an audio playback and recording unit. The shape of the invention is preferably a human shape in a soft sculpture, with a frame capable of holding a photograph. The audio playback and recording unit is activated by at least one remote button. The audio playback and recording unit contains a microphone or other audio input device and a speaker or other audio output device. The audio playback and recording unit and power supply are enclosed within the soft sculpture with sufficient cushioning that the presence of such relatively hard objects is not easily felt while the soft sculpture is hugged or squeezed. The overall impression of the picture frame is a huggable doll, which with a selected photograph, presents a reminder of a particular person to the user of the picture frame.
    Type: Grant
    Filed: July 30, 2012
    Date of Patent: February 3, 2015
    Inventor: Audrey Storch
  • Patent number: 8947820
    Abstract: The implementations disclosed herein provide for a storage device including a preamplifier that generates a write current pulse having a region of reduced slew rate that temporally correlates with a time when a magnetization of a write pole tip switches polarity.
    Type: Grant
    Filed: April 30, 2014
    Date of Patent: February 3, 2015
    Assignee: Seagate Technology LLC
    Inventors: Kirill Rivkin, Yanzhang Liu, Mourad Benakli, Huaqing Yin
  • Patent number: 8922932
    Abstract: Each of unit blocks (UB1, UB2) is provided with an output circuit (20) including a serial circuit of FETs (21) and (22). A power supply circuit (1b) can operate in a first mode for generating an output voltage (Vo) using only one of the output circuits (20) or in a second mode for generating the output voltage (Vo) using two output circuits (20) by synchronous/parallel driving. When switching from the first mode to the second mode, start of the synchronous/parallel driving from a state where the FET (22) on the low voltage side is turned on is inhibited (start of the synchronous/parallel driving is waited until the FET (21) on the high voltage side is turned on).
    Type: Grant
    Filed: April 23, 2014
    Date of Patent: December 30, 2014
    Assignee: Rohm Co., Ltd.
    Inventor: Hirotaka Nakabayashi
  • Patent number: 8817400
    Abstract: A data storage device includes a storage medium on which data is stored in overlapping tracks, and a medium controller that directs storage of data on, and reading of data from, the storage medium, including encoding data being stored and decoding data being read. The decoding includes, when reading a first track, cancelling interference from a second track that overlaps the first track. The data storage device also includes a host controller in communication with the medium controller. The host controller includes memory that stores data decoded, and data to be written, by the medium controller. Communication between the medium controller and the host controller includes signals derived from data on said first and second tracks for facilitating the cancelling. A method of operating a data storage device includes, when reading a first track, facilitating the cancelling by communicating signals derived from the data on the first and second tracks.
    Type: Grant
    Filed: November 2, 2011
    Date of Patent: August 26, 2014
    Assignee: Marvell International Ltd.
    Inventors: Nitin Nangare, Hongying Sheng, Vincent Wong, Gregory Burd
  • Patent number: 8804261
    Abstract: A write driver circuit for generating a write current pulse for use by a magnetic write head includes an output stage adapted for connection with the magnetic write head and a charge storage circuit connected with the output stage. The charge storage circuit is operative in a first mode to store a prescribed charge and is operative in a second mode to transfer at least a portion of the charge stored therein to the output stage to thereby enable an output voltage level of the output stage to extend beyond a voltage supply rail of the write driver circuit. A control circuit in the write driver circuit is operative to generate at least one control signal for selectively controlling a mode of operation of the charge storage circuit.
    Type: Grant
    Filed: July 27, 2012
    Date of Patent: August 12, 2014
    Assignee: LSI Corporation
    Inventors: Paul Mark Mazur, Michael Joseph Peterson
  • Patent number: 8767340
    Abstract: Methods, systems and computer program products for detecting an end of a reference spiral band are described. A first portion of servo information may be written on a disk using the reference spiral band. By detecting an end of a reference spiral band, a new reference spiral band may be launched. A read/write head of a hard disk drive may subsequently use the new spiral band to write the remaining portion of the servo information, which aids the writing of data tracks on the disk.
    Type: Grant
    Filed: June 12, 2012
    Date of Patent: July 1, 2014
    Assignee: Marvell International Ltd.
    Inventors: Perry Neos, Luan Ton-That, Man Cheung
  • Patent number: 8737002
    Abstract: A magnetic recording disk has nondata regions that contain a group of first nondata islands with one area and a magnetization in one perpendicular direction, and a group of second nondata islands with a smaller area and a magnetization in the opposite direction. To magnetize the nondata islands with the proper magnetization directions, a DC magnetic field much greater than the coercive field of the magnetic recording layer is applied in one direction to the entire disk to magnetize all of the nondata islands in the same direction. Then the disk is heated to a predetermined temperature, and while the disk is at this temperature, a second DC magnetic field less than the first DC magnetic field is applied for a predetermined time in the opposite direction to the entire disk. This reverses the magnetization direction of the smaller islands without switching the magnetization of the larger islands.
    Type: Grant
    Filed: March 26, 2013
    Date of Patent: May 27, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Abhishek Dhanda, Michael Konrad Grobis, Toshiki Hirano, Tetsuo Semba
  • Patent number: 8717699
    Abstract: A voltage booster is disclosed comprising an input for receiving an input voltage Vin, a first charging capacitor C1, a second charging capacitor C2, and an output capacitor Cout. The output capacitor Cout is charged to four times Vin by connecting C1 in parallel with Vin to charge C1 to Vin, after charging C1 to Vin, connecting C2 in parallel with Vin plus C1 to charge C2 to twice Vin, after charging C2 to twice Vin, connecting C1 in parallel with Vin to recharge C1 to Vin, and after recharging C1, connecting Cout in parallel with Vin plus C1 plus C2 to charge Cout to four times Vin.
    Type: Grant
    Filed: January 10, 2012
    Date of Patent: May 6, 2014
    Assignee: Western Digital Technologies, Inc.
    Inventor: Timothy A. Ferris
  • Patent number: 8654467
    Abstract: A disk drive is disclosed comprising a disk including a plurality of servo tracks defined by servo sectors, wherein each servo sector comprises a servo preamble. A head is actuated over the disk, wherein the head is operable to generate a read signal. The disk drive further comprises control circuitry including an analog cutoff filter operable to filter the read signal to generate a filtered read signal. The filtered read signal is sampled to generate read samples. During a normal operating mode, the analog cutoff filter is configured to have a first bandwidth. During a measurement mode, the analog cutoff filter is configured to have a second bandwidth greater than the first bandwidth, and the read samples representing at least part of the servo preamble are processed to measure a signal-to-noise ratio (SNR) and/or a fly height of the head.
    Type: Grant
    Filed: April 16, 2012
    Date of Patent: February 18, 2014
    Assignee: Western Digital Technologies, Inc.
    Inventors: Wai Ee Wong, Xiaotian Xu, Jinchuan Zheng, Guoxiao Guo, Jie Yu
  • Patent number: 8643970
    Abstract: According to one embodiment, a magnetic recording apparatus configured to record information onto a magnetic recording medium by a shingled write recording method, the magnetic recording apparatus includes: a recording head configured to cover a plurality of dot arrays and an end portion of which is situated at one dot array of a recording target; an actuator configured to move the recording head by one array after the recording to one dot array by the recording head; and a controller configured to perform recording compensation of the magnetic dot based on prestored recording data of a peripheral dot of a magnetic dot when input user data is recorded to the magnetic dot.
    Type: Grant
    Filed: January 24, 2012
    Date of Patent: February 4, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Naoki Tagami, Kazuto Kashiwagi, Akihiro Itakura, Haruhiko Izumi, Masatoshi Sakurai
  • Publication number: 20130314816
    Abstract: In order to improve a consistent data track during writing to a storage medium, a plurality of read sensors are affixed to a transducer head. In one implementation, the transducer head includes multiple read sensors placed up-track of the write pole. In another implementation, the transducer head includes at least one read sensor placed up-track of the write pole and at least one read sensor placed down-track of the write pole. Each position of the multiple read sensors relative to the write pole may be unique. One or more read signals of selected read sensors are used to determine the read location and therefore the write pole location relative to the storage medium.
    Type: Application
    Filed: July 31, 2013
    Publication date: November 28, 2013
    Applicant: Seagate Technology LLC
    Inventors: Kaizhong Gao, Olle Heinonen, Yonghua Chen
  • Patent number: 8582226
    Abstract: Apparatus and method for write delay stabilization. A write driver is adapted to output bipolar write currents to write data to a memory. A preconditioning circuit is adapted to output first and second thermal preconditioning currents through the write driver to stabilize a write delay associated with the write driver to a steady-state level prior to the writing of data to the memory.
    Type: Grant
    Filed: March 15, 2012
    Date of Patent: November 12, 2013
    Assignee: Seagate Technology LLC
    Inventors: David Erich Tetzlaff, Bruce Douglas Buch
  • Publication number: 20130027804
    Abstract: One embodiment of the invention includes a system for writing data onto a magnetic disk. An output driver provides a first write current through a first output transistor in a first state and provides a second write current through a second output transistor in a second state. The first and second write currents can be provided to a disk write head to store opposing binary values, respectively. A bias current generator switches a first bias current between an intermediate voltage node in the second state and a first control node in the first state, and switches a second bias current between the intermediate voltage node in the first state and a second control node in the second state. The first and second bias currents can be provided to set a bias voltage at the first and second control nodes to bias the first and second output transistors, respectively.
    Type: Application
    Filed: October 4, 2012
    Publication date: January 31, 2013
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventor: Texas Instruments Incorporated
  • Patent number: 8310777
    Abstract: In one general embodiment, a recording system controller includes a controller controlling a timing of flux switching of adjacent pairs of writers such that the writers in a given pair do not switch substantially concurrently, and reducing a current of one of the writers in the pair while the adjacent writer is writing a transition. In another general embodiment, a recording system controller includes a controller controlling a timing of pulse writing of adjacent pairs of writers such that the writers in a given pair do not pulse substantially concurrently. In yet another general embodiment, a method includes controlling a timing of pulse writing or flux switching of adjacent pairs of writers such that the writers in a given pair do not pulse or switch substantially concurrently.
    Type: Grant
    Filed: September 9, 2009
    Date of Patent: November 13, 2012
    Assignee: International Business Machines Corporation
    Inventors: Robert G. Biskeborn, Philipp Herget, Pierre-Olivier Jubert
  • Patent number: 8279545
    Abstract: A method of transferring data of one or more rotatable data storage devices includes but is not limited to rotating the at least one rotatable data storage device; transferring the data between a plurality of stationary data transfer heads and the one or more rotatable data storage devices; and using one or more computer programs to determine which of the plurality of stationary data transfer heads are to be used to transfer a first portion of the data between the plurality of stationary data transfer heads and the one or more rotatable data storage devices and the direction in which the first portion of the data is to be transferred. In addition to the foregoing, other method aspects are described in the claims, drawings, and text forming a part of the present application. Other methods and apparatuses are also disclosed.
    Type: Grant
    Filed: May 1, 2007
    Date of Patent: October 2, 2012
    Assignee: The Invention Science Fund I, LLC
    Inventors: W. Daniel Hillis, Roderick A. Hyde, Muriel Y. Ishikawa, Edward K. Y. Jung, Nathan P. Myhrvold, Lowell L. Wood, Jr.
  • Publication number: 20120206830
    Abstract: In order to improve a consistent data track during writing to a storage medium, a plurality of read sensors are affixed to a transducer head. In one implementation, the transducer head includes multiple read sensors placed up-track of the write pole. In another implementation, the transducer head includes at least one read sensor placed up-track of the write pole and at least one read sensor placed down-track of the write pole. Each position of the multiple read sensors relative to the write pole may be unique. One or more read signals of selected read sensors are used to determine the read location and therefore the write pole location relative to the storage medium.
    Type: Application
    Filed: February 16, 2011
    Publication date: August 16, 2012
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Kaizhong Gao, Olle Heinonen, Yonghua Chen
  • Publication number: 20120014014
    Abstract: Provided is a method for recording data to a tape medium in such a manner as to achieve the easy management of mutually related multiple data pieces. First data and second data continuously received as a file from a higher level apparatus are accumulated in multiple buffer segments in the form of multiple successive data sets. A data structure is determined for each of the accumulated data sets. Management information indicating a result of the determination is added to the data sets, and the data sets and the management information thereof are stored into the tape medium.
    Type: Application
    Filed: January 29, 2010
    Publication date: January 19, 2012
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Hiroshi Itagaki, Toshiyuki Shiratori
  • Patent number: 8085492
    Abstract: The present disclosure includes systems and techniques relating to magnetic recording devices, such as disk drives. A recording medium of a magnetic recording device can include multiple helicoid patterns arranged in multiple helicoid groups. A described technique includes receiving a waveform produced by a head operated with respect to the medium; determining, based on the waveform, first phase difference(s) corresponding to a first helicoid group; affecting an alignment of the head with respect to the medium based on the first helicoid group by compensating for the first phase difference(s) to maintain the alignment; determining, while compensating for the first phase differences, second phase difference(s) corresponding to a second helicoid group; and affecting, responsive to a switch from the first helicoid group to the second helicoid group, the alignment of the head with respect to the medium by compensating for the second phase difference(s) to maintain the alignment.
    Type: Grant
    Filed: December 20, 2010
    Date of Patent: December 27, 2011
    Assignee: Marvell International Ltd.
    Inventors: Man Cheung, Perry Neos, David Rutherford
  • Patent number: 8040627
    Abstract: Methods and apparatus for generating a hard drive write signal are here in disclosed. A disclosed method comprises generating a hard drive write signal on an output of a switch based on an edge of the first control signal and reducing the hard drive write signal based on an edge of a second control signal via a second switch.
    Type: Grant
    Filed: January 17, 2008
    Date of Patent: October 18, 2011
    Assignee: Texas Instruments Incorporated
    Inventors: Jeremy Robert Kuehlwein, Scott Gary Sorenson
  • Patent number: 8040631
    Abstract: The operational bandwidth of a servo control circuit can be increased using a plurality of servo processors that handoff between them the responsibility for controlling head positioning in response to sequentially occurring servo patterns.
    Type: Grant
    Filed: May 18, 2009
    Date of Patent: October 18, 2011
    Assignee: Seagate Technology LLC
    Inventor: Randall David Hampshire
  • Patent number: 8027119
    Abstract: The application relates to an adaptive vibration damping scheme that provides for detection of, and adjustment for, vibration-related disturbances in devices. The vibration damping scheme utilizes a common filter function to implement vibration detection and vibration compensation.
    Type: Grant
    Filed: November 7, 2007
    Date of Patent: September 27, 2011
    Assignee: Seagate Technology LLC
    Inventor: Tao Zhang
  • Publication number: 20110216436
    Abstract: Excellent magnetization switching of a magnetic recording medium is promoted in microwave assisted magnetic recording to provide a highly-reliable high-density information recording device. A receded section from an air bearing surface is arranged at an end section in a write track width direction on an FGL laminate film for generating a high-frequency field. Alternatively, a cross section of the FGL laminate film (plane perpendicular to the direction of the flow of the electric current) has an inverted trapezoid shape or has a structure in which the area of the cross section increases with distance from the main pole. Since an excellent recording pattern is formed on the recording medium, areal recording density in the information recording device can be increased, and the reliability can be improved at the same time. As a result, the cost can be reduced.
    Type: Application
    Filed: November 10, 2009
    Publication date: September 8, 2011
    Inventors: Masukazu Igarashi, Harukazu Miyamoto
  • Patent number: 7889452
    Abstract: Hard disk drive preamplifier timers and methods to calibrate hard disk drive preamplifier timers are disclosed. A timer in a hard disk drive preamplifier comprises a first switch to selectively store charge in a storage device based on an input signal, the storage device receiving a first current and storing the charge to cause the storage device to have a first voltage that increases at a first rate; a compensation device to cause the first voltage to be substantially equal to a second voltage after a predetermined time period; and a trigger to output a signal when the first voltage is substantially equal to the second voltage, the predetermined time period controlling a transition time between a first hard disk drive operating condition and a second hard disk drive operating condition different than the first operating condition.
    Type: Grant
    Filed: March 31, 2008
    Date of Patent: February 15, 2011
    Assignee: Texas Instruments Incorporated
    Inventors: Bryan E. Bloodworth, Nilakantan Seshan, Benjamin Sarpong, Ashish Manjrekar
  • Patent number: 7880998
    Abstract: Two pass writing system and method for patterned media. In a first step, a write head of a hard disk drive writes with a strong write field. In a second step, a write head of the hard disk drive writes with a weak field. In this manner, magnetic islands of patterned media are written in the first step. In the second step, only those magnetic islands with a low switching field are written.
    Type: Grant
    Filed: December 21, 2007
    Date of Patent: February 1, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Xiao Z. Wu
  • Patent number: 7869158
    Abstract: A recording medium can include multiple helicoid patterns arranged in multiple helicoid groups, e.g., first and second helicoid groups. Operating a disk drive can include switching between helicoid groups to maintain the alignment of the head with respect to a target track of the rotating recording medium. Enabling a switch can include receiving a waveform produced by a head operated with respect to a rotating recording medium, generating first information from one or more portions of the waveform corresponding to the helicoid patterns of the first helicoid group; generating second information from one or more portions of the waveform corresponding to the helicoid patterns of the second helicoid group; and analyzing the second information with respect to the first information to generate calibration information. The calibration information can compensate for operational differences between using the helicoid patterns of the first helicoid group and the helicoid patterns of the second helicoid group.
    Type: Grant
    Filed: August 15, 2008
    Date of Patent: January 11, 2011
    Assignee: Marvell International Ltd.
    Inventors: Man Cheung, Perry Neos, David Rutherford
  • Patent number: 7796354
    Abstract: A method for controlling data rate of a tape drive is disclosed. The tape drive is connected to a computer system. The tape drive stores data by dividing the data into multiple codeword quads (CQs). A local memory within the tape drive includes drive to iteratively monitor data rate during write operations. If a number of CQ skips exceeds a pre-defined threshold value, the drive code reduces a maximum allowable data rate of the tape drive.
    Type: Grant
    Filed: October 16, 2007
    Date of Patent: September 14, 2010
    Assignee: International Business Machines Corporation
    Inventor: Roger J. Justo
  • Patent number: 7766236
    Abstract: A method for reading data using a magnetic head having a first array of elements associated with a first data format, and a second array of elements associated with a second data format, the elements being selected from a group consisting of readers, writers, and combinations thereof, wherein the first and second arrays of elements are generally laterally adjacent each other in a direction transverse to a direction of travel of a magnetic medium over the head, the method comprising: determining a format of data on a medium; selecting one of the arrays of elements to read the data on the medium based on the determined format of the data; and positioning the selected array over the data on the medium.
    Type: Grant
    Filed: July 17, 2008
    Date of Patent: August 3, 2010
    Assignee: International Business Machines Corporation
    Inventors: Robert Glenn Biskeborn, Calvin Shyhjong Lo
  • Patent number: 7755862
    Abstract: An apparatus for writing a magnetic layer writable with either low or high coercive field strength includes a magnetic head having a magnet coil and a voltage source. The apparatus includes switches between the voltage source and opposing ends of the magnet coil. Two further switches serve to maintain the direction of current flow through the magnet coil. A current measuring device determines the current intensity through the magnet coil. The current measuring device drives the switches in such a way that the current intensity in the magnet coil does not exceed or undershoot a level required for writing the magnetic layer.
    Type: Grant
    Filed: November 2, 2005
    Date of Patent: July 13, 2010
    Assignee: SkiData AG
    Inventor: Johann Praeauer
  • Patent number: 7746590
    Abstract: A current mirror circuit providing a fast turn on time. A node within the circuit is held at a first voltage when the current mirror is off to permit the node voltage to quickly reach a necessary value when the current mirror circuit is turned on.
    Type: Grant
    Filed: May 27, 2005
    Date of Patent: June 29, 2010
    Assignee: Agere Systems Inc.
    Inventor: Jonathan H. Fischer
  • Patent number: 7679854
    Abstract: A disk drive for implementing a head switch operation is disclosed. The disk drive comprises: an actuator; a first head and a second head attached to the actuator; a disk having a plurality of tracks; and a processor. The processor controls operations in the disk drive including: executing a head switch command from the first head to the second head; determining that a sync-up operation is not successful for the second head at a first track; applying a torque to the actuator to move the second head to a second track; and determining that the sync-up operation is successful.
    Type: Grant
    Filed: October 29, 2008
    Date of Patent: March 16, 2010
    Assignee: Western Digital Technologies, Inc.
    Inventors: Aswartha Narayana, John Yin Kwong Li, Gary Gaoxiang Zhu, Jonathan V. Nguyen, Duc T. Phan
  • Patent number: 7667915
    Abstract: According to one embodiment, a disk drive is provided which has a head amplifier having a function of, at a data recording time, outputting AC pattern data to a write head prior to the recording of the write data to allow it to be recorded on a write splice section on a disk medium. The write head records an AC signal pattern of a high frequency on the write splice section on the disk medium according to an output timing of a write gate and then write data is recorded with a preamble as a header.
    Type: Grant
    Filed: November 20, 2006
    Date of Patent: February 23, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Masakazu Abe
  • Patent number: 7616395
    Abstract: There is provided an information reproduction apparatus that can suppress degradations in the qualities of reproduced data and timing from due to interpolation errors when performing interpolation timing recovery, and that can avoid degradation in the stability of the system due to an increase in the timing recovery loop delay. An information reproduction apparatus (100) for reproducing data and timing from an analog signal including data information and timing information is provided with an expected value generator (106) for outputting plural expected values, and a maximum likelihood detector (107) for outputting data that corresponds to a sequence of the highest likelihood with an output sequence of an A/D converter among the plural expected value sequences, at the timing of a second clock.
    Type: Grant
    Filed: August 15, 2005
    Date of Patent: November 10, 2009
    Assignee: Panasonic Corporation
    Inventor: Akira Yamamoto
  • Patent number: 7595951
    Abstract: A (e.g., hard-disk drive (HD)) system supports reader standby mode and/or writer standby mode. For reader standby mode, reader circuitry in the system's preamplifier is transitioned to a low-power mode during write operations. To provide quick transition from write mode to read mode, the reader circuitry is transitioned to pre-read mode before the end of the write operation. For writer standby mode, the preamplifier's writer circuitry is transitioned to a low-power mode during read operations. To provide quick transition from read mode to write mode, the writer circuitry is transitioned to a pre-write mode before the end of the read operation. The availability of a reader standby mode during write operations and a writer standby mode during read operations reduces power consumption as compared to HD systems that leave the reader circuitry in pre-read mode throughout each write operation and the writer circuitry in pre-write mode throughout each read operation.
    Type: Grant
    Filed: June 2, 2006
    Date of Patent: September 29, 2009
    Assignee: Agere Systems Inc.
    Inventors: Daniel J. Dolan, David W. Kelly, Stephen C. Kuehne, Nathan M. Rudd, Ross S. Wilson
  • Publication number: 20090097149
    Abstract: A method for controlling data rate of a tape drive is disclosed. The tape drive is connected to a computer system. The tape drive stores data by dividing the data into multiple codeword quads (CQs). A local memory within the tape drive includes drive to iteratively monitor data rate during write operations. If a number of CQ skips exceeds a pre-defined threshold value, the drive code reduces a maximum allowable data rate of the tape drive.
    Type: Application
    Filed: October 16, 2007
    Publication date: April 16, 2009
    Inventor: ROGER J. JUSTO
  • Patent number: 7502427
    Abstract: A repeatable read-out (RRO) detector employs one or more digital interpolators to interpolate asynchronous sample values that represent RRO data. The asynchronous sample values are read from a recording medium and generated by an A/D converter at a symbol rate, and the interpolators generate interpolated samples at at least one time in between the asynchronous sample value times. Each interpolated sample corresponding to some phase relative to that of the sample values generated by the A/D converter. The RRO detector receives 1) the asynchronous samples at symbol rate and 2) the interpolated samples to efficiently detect the encoded RRO data. An RRO address mark indicates when detection of encoded RRO data starts, and is employed to select those samples suitable for RRO data detection. Detection of the RRO address mark employs peak detection among filtered asynchronous and interpolated samples. The process of peak detection adjusts the current best phase for sample selection.
    Type: Grant
    Filed: May 30, 2006
    Date of Patent: March 10, 2009
    Assignee: Agere Systems Inc.
    Inventors: Viswanath Annampedu, Pervez M. Aziz
  • Patent number: 7492542
    Abstract: A method of storing and accessing data from a storage device. The method includes providing a storage that includes a first interface associated with a read-write head configured to read and write data to the storage, the storage further having a second interface associated with a read-only head configured to only read data from the storage, where the first interface includes a hardware selection switch for configuring a first head assembly carrying the read-write head to read data from and write data to the storage, and where the second interface includes a second hardware selection switch for configuring a second head assembly carrying the read-only head to only read data from the storage, and where a first computer connected to the first interface can both read and write data to the storage, while a second computer connected to the second interface can only read data from the storage.
    Type: Grant
    Filed: August 29, 2007
    Date of Patent: February 17, 2009
    Assignee: International Business Machines Corporation
    Inventor: Jacques M. J. van Zyl
  • Patent number: 7466506
    Abstract: A magnetic recording disk drive has disks with identical pre-patterned servo patterns on their front and back surfaces and a servo control system for positioning the read/write heads using the servo signals from the identical servo patterns. The servo sectors on the two disk surfaces form identical patterns of angularly spaced arcuate-shaped lines that extend generally radially across the data tracks. The arcuate-shaped lines on one surface, the front surface, generally replicate the path of the recording head as it is moved across the data tracks by a rotary actuator, so that there is a constant sampling rate of the servo sectors on the front surface regardless of radial position of the head. However, the arcuate-shaped lines on the other surface, the back surface, do not replicate the path of the recording head so the servo sampling rate is not constant but varies with radial position of the head.
    Type: Grant
    Filed: June 19, 2007
    Date of Patent: December 16, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Thomas R. Albrecht, Zvonimir Z. Bandic