Class / Patent application number | Description | Number of patent applications / Date published |
360066000 | Specifics of biasing or erasing | 31 |
20080212221 | METHOD OF SETTING AC ERASE FREQUENCY AND AC ERASE METHOD BASED ON DATA FREQUENCY - A method of setting an AC erase frequency using a data frequency of a disk area and an AC erase method. The method of setting the AC erase frequency includes obtaining a data frequency for each disk area, and setting an AC erase frequency for each disk area based on the data frequency for each disk area. | 09-04-2008 |
20090080103 | STORAGE DEVICE AND SEEK CONTROL METHOD - A storage device includes a storage unit, a timer unit and a bias current applying unit. The storage unit stores, in advance, a value of a waiting time until application of a bias current to the driving unit to eliminate an external force applied to an actuator after completion of positioning, and a value of a bias current to be applied to the driving unit after the elapse of the waiting time, in association with a track position. The timer unit reads the waiting time from the storage unit and counting an elapse of the waiting time. The bias current applying unit reads the bias current value from the storage unit and applying the bias current to the driving unit after the elapse of the waiting time. | 03-26-2009 |
20090201601 | Magnetic Data Eraser - A magnetic data eraser includes a power supply circuit, a receptacle for accommodating a magnetic recording medium or a device incorporating a magnetic recording medium, primary and secondary coils wound around an outer periphery of the receptacle. The primary coil is connected to the power supply circuit. The secondary coil is short-circuited. Excitation of the primary coil through energization by the power supply circuit generates an induced current in the secondary coil, thereby making an interaction between the primary and secondary coils. The interaction generates an alternating magnetic field, whereby the magnetic recording medium is degaussed, so as to erase magnetic data recorded in the medium. | 08-13-2009 |
20100027151 | SECURE DATA DISPOSAL FOR DISK DRIVE - When a disk sector is written to, a bit for the sector is set indicating that the sector will require secure data disposal (SDD) to be run on it. To save time during end of life disposal, SDD is executed only on sectors whose bits indicate that they have been written to. SDD can be executed on each dirty sector in one operation at end of life or incrementally during use as disk activity permits. | 02-04-2010 |
20100149677 | SELF-SPINNING DISK BULK ERASURE FOR HARD DISK ASSEMBLY - A method for erasing a disk of a hard disk drive. The method includes moving the hard disk drive adjacent to an erasure head that emanates a magnetic field. The magnetic field and moving hard disk drive cause a disk of the hard disk drive to spin under a Lorentz force created by the magnetic field and moving disk. The magnetic field is applied by the erasure head for a duration that causes erasure of the entire disk. The spindle motor is not activated during the entire process. Not activating the spindle motor eliminates any Faraday coupling from the erasure head into the motor. | 06-17-2010 |
20100149678 | METHOD OF MANUFACTURING A HARD-DISK DRIVE USING A BULK ERASER - A method of manufacturing of a hard-disk drive using a bulk eraser for erasing recorded information on a magnetic-recording disk. The method includes providing a bulk eraser that produces magnetic-flux density in a gap sufficient to erase recorded information from a magnetic-recording disk, a hard-disk drive, a disk-stack having at least one magnetic-recording disk, and a drive motor for rotating the magnetic-recording disk. The method also includes configuring a plurality of magnets and a structure of the bulk eraser such that magnetic-flux density is oriented parallel to and in a radial direction of the magnetic-recording disk; and rotating the magnetic-recording disk. The method further includes inserting the hard-disk drive into the gap of the bulk eraser; and erasing recorded information from the magnetic-recording disk located in the gap; and removing the hard-disk drive from the gap. | 06-17-2010 |
20100149679 | BULK ERASER INCLUDING AT LEAST THREE MAGNETS CONFIGURED FOR ERASING RECORDED INFORMATION - A bulk eraser for erasing recorded information on a magnetic-recording disk. The bulk eraser includes at least three magnets and a structure magnetically coupled with the at least three magnets to produce magnetic-flux density in a gap. The gap has a first portion, a second portion and a third portion, such that a first magnet and a second magnet are disposed with opposing end poles across the first portion. The at least three magnets and the structure are configured to produce a magnetic-flux density in the second portion sufficient to erase recorded information from a portion of at least one magnetic-recording disk in a disk-stack when a hard-disk drive is inserted into the second portion. In addition, the at least three magnets and the structure are configured to direct the magnetic-flux density in a substantially radial direction of the portion of the magnetic-recording disk in the second portion. | 06-17-2010 |
20100195241 | ZONE TEXTURED RECORDING HEAD - The present disclosure relates to a magnetic recording head having a slider media bearing interface surface with surface modifications configured to reduce friction and/or stiction friction properties between the head slider media bearing interface surface and a recording medium. The present disclosure also relates to a tape drive system, a method of formatting a recording medium using such a magnetic recording head, and the resulting formatted media. | 08-05-2010 |
20100277824 | SYSTEM AND METHOD FOR SETTING BIAS FOR MR HEAD - A device for setting a bias for a magneto-resistive (MR) head can include a counter configured to provide a count value that varies incrementally from a first count value to a maximum count value. Logic is configured to determine at least one of whether the bias for the MR head has reached a predetermined threshold and whether the counter has reached the maximum count value. The logic provides a bias output signal corresponding to the count value for setting the bias of the MR head according to the determination by the logic. | 11-04-2010 |
20110026157 | SECURE DATA DISPOSAL FOR DISK DRIVE - When a disk sector is written to, a bit for the sector is set indicating that the sector will require secure data disposal (SDD) to be run on it To saw time during end of life disposal, SDD is executed only on sectors whose bits indicate that they have been written to. SDD can be executed on each dirty sector in one operation at end of life or incrementally during use as disk activity permits. | 02-03-2011 |
20110261481 | MAGNETIC STRUCTURE FOR ERASING DISK OR DISKS WITHIN HARD DISK DRIVES - A structure for erasure of magnetic media in a hard drive includes a main field pole magnet polarized in a direction toward a drive spindle motor in the hard drive. At least two quadrature magnets are disposed adjacent the main field pole magnet and polarized in a direction toward the main field pole magnet. The main field pole magnet and the at least two quadrature magnets are shaped to provide a slot for insertion of the magnetic media. At least two inverse polarity magnets are disposed on portions of the main pole and quadrature magnets forming the slot. The inverse polarity magnets are polarized in a direction opposed to the direction of the main field pole magnet. | 10-27-2011 |
20110279922 | MAGNETIC DATA ERASER - The present invention relates providing a magnetic data eraser that is capable of performing magnetizing process for magnetizing magnetic recording medium such as a hard disk drive (HDD) is easily and with reduced electric power. | 11-17-2011 |
20120081810 | MAGNETIC DISK DRIVE USING OFFSET IN POSITIONING HEAD TO READ DATA AND HEAD POSITIONING METHOD - According to one embodiment, a magnetic disk drive comprises a write count memory, a read offset setting module and a controller. The write count memory stores a write count for each track or for each zone on a disk. The read offset setting module sets, in accordance with a write count for an adjacent track to a target track or for a zone to which the adjacent track belongs, an offset from a predetermined position on the target track in a read position in which a head is to be positioned when the head is positioned on the target track for data read. The write count is stored in the write count memory. The controller positions the head in a position shifted from the predetermined position by the set offset. | 04-05-2012 |
20120105997 | INDUCTION OF MAGNETIC BIAS IN A MAGNETIC RECORDING DISK - Approaches for inducing a magnetic bias in a magnetic recording disk. A biasing apparatus comprises a soft magnetic material member having a shape comprising two opposing recesses, denoted an upper recess and a lower recess. A first magnet is disposed within the upper recess and a second magnet disposed within the lower recess. An air gap exists between the first magnet and the second magnet. An opening in the soft magnetic material member is sized to accommodate at least a portion of the magnetic recording disk between the first magnet and the second magnet. The magnetic field produced by both the first magnetic and the second magnetic flows (a) in the same direction, and (b) perpendicular to the plane of the magnetic recording disk. Using this approach, magnetic material on the disk, such as magnetic islands of a bit pattern media, may be erased and polarized in the same direction. | 05-03-2012 |
20120262817 | BIAS TECHNIQUES FOR MAGNETIC TAPE MEDIA - The disclosure is directed to a method for creating a remnant magnetization on a magnetic tape medium. The magnetic tape is first substantially demagnetized, e.g., erased, by an erasure unit having multiple magnetic elements of alternating polarity. The erased magnetic tape is then passed by a bias magnet that creates a remnant magnetization on the magnetic tape. The remnant magnetized magnetic tape is then passed through a servo write head that writes servo patterns to the remnant magnetized magnetic tape. The bias magnet may be housed within the erasure unit or within a bias unit, and the distance between the bias magnet and the tape path of the magnetic tape may be adjustable to create the desired remnant magnetization on the magnetic tape. The remnant magnetization created on the magnetic tape may be greater than 20 percent to reduce defects in the servo pattern written to the magnetic tape. | 10-18-2012 |
20120307394 | WRITER HAVING A SHIELD STRUCTURE FOR ADJACENT AND FAR TRACK INTERFERENCE REFRESHMENT - In one embodiment, a data storage system includes a magnetic head having a main magnetic pole and a wrap around shield positioned around the main magnetic pole at an ABS thereof, a magnetic medium, a drive mechanism for passing the magnetic medium over the magnetic head, and a controlling mechanism electrically coupled to the magnetic head for controlling operation of the magnetic head that initiates rewriting of information of a recording track of the magnetic medium if a recording magnetic field applied to the recording track exceeds a threshold. In another embodiment, a method includes writing data to a first track of a magnetic medium using a magnetic head, determining characteristics consistent with data degradation from tracks adjacent to the first track and far tracks away from the first track using a controlling mechanism, and rewriting data in tracks determined to be degraded due to ATI and/or FTI. | 12-06-2012 |
20120327530 | MAGNETIC DATA ERASER - The present invention relates providing a magnetic data eraser that is capable of performing magnetizing process for magnetizing magnetic recording medium such as a hard disk drive (HDD) is easily and with reduced electric power. | 12-27-2012 |
20130003217 | HEAD-DISK INTERFERENCE (HDI) DETECTION - Method and apparatus for detecting head disk interference (HDI). In accordance with some embodiments, a bias calibration circuit is adapted to respectively bypass or amplify a head disk interference (HDI) signal output from an HDI sensor responsive to a bias voltage adjusted according to a first control signal. A detection circuit is adapted to compare a swing range of a signal output from the bias calibration circuit and a swing range of a reference signal, and to output the first control signal responsive to said comparison. | 01-03-2013 |
20130021691 | MAGNETIC STORAGE DEVICE WITH CHIRPED WRITE HEAD DEGAUSSING WAVEFORM - A circuit for use with a memory storage device including a magnetic storage medium and a write head operative to subject the magnetic storage medium to a magnetic field in response to an application of current to the write head, includes a write circuit operative to generate a write current supplied to the write head. The write current is characterized by a current waveform that reverses polarity in accordance with data to be stored on the magnetic medium. The circuit for use with the memory storage device further includes a degauss circuit operative to generate a degaussing current supplied to the write head. The degaussing current is characterized by a current waveform that oscillates between opposite polarities with an amplitude and a frequency that change over time. | 01-24-2013 |
20130063836 | TAPE DRIVE PROVIDED WRITE FORMAT FOR OVERWRITE ERASURE OF MAGNETIC TAPE DATA RECORDED IN TRACKS - A magnetic tape drive has a drive system to move a magnetic tape longitudinally; servo head(s) for reading servo band information from a magnetic tape as the magnetic tape is moved longitudinally; a magnetic tape read write head configured to read and to write the magnetic tape, having a data write width (w) greater than a normal shingled track pitch width (p) of the magnetic tape; an actuator system for positioning the read write head laterally; and a control. The magnetic tape drive stores an overwrite erase format of non-shingled track pitch longitudinal pattern(s) whose pitch is greater than the normal shingled track pitch width (p); and, the control, in response to activation of overwrite erasure of the tape drive, operates the actuator system and the magnetic tape read write head to write non-data to magnetic tape in the stored overwrite erase format. | 03-14-2013 |
20130135767 | IMPLEMENTING ENHANCED FRAGMENTED STREAM HANDLING IN A SHINGLED DISK DRIVE - A method and a storage system are provided for implementing fragmented stream handling for persistent media including shingled disk drives (SDDs). A plurality of Exception Regions for recording stream commands is defined for disk regions. One state is maintained in each of the Exception Regions including a free Exception Region, an active Exception Region, a recovery Exception Region and a used Exception Region. TRIM commands are issued by a host to the drive to indicate deleted content. | 05-30-2013 |
20130329314 | MAGNETIC DATA ERASER - The magnetic data eraser includes: a mounting and immobilizing tray on which a magnetic recording medium is mounted, the mounting tray being inclined at an angle of 60±10 degrees to the horizontal; a magnetizer that is encircled by a magnetizing coil, the magnetizer having a hollow portion into which the mounting and immobilizing tray is inserted; and a controller that causes an electric current to flow as an excitation current through the magnetizing coil, the excitation current generating a magnetic field that erases data stored in the magnetic recording medium. | 12-12-2013 |
20140036385 | ZERO GAIN START BIAS ESTIMATION - A method and system for estimating a zero gain start (ZGS) bias in a read channel is disclosed. The method may include: receiving preamble samples within a fixed-length window selected for ZGS calculation; calculating an energy associated with a 2T frequency in the preamble samples; calculating an energy associated with non-2T frequencies in the preamble samples; and calculating the ZGS bias based on the energy associated with the 2T frequency in the preamble samples and the energy associated with non-2T frequencies in the preamble samples. | 02-06-2014 |
20140063638 | DYNAMICALLY CONTROLLING MAGNETORESITIVE BIAS - Magnetoresistive (MR) bias is dynamically controlled in a tape drive using a processor device. Upon determining head amplitude is below a threshold value, the MR bias is adjusted for increasing the head amplitude and extending the useful life span of the tape drive. | 03-06-2014 |
20140071560 | MAGNETIC RECORDING ASSISTED BY SPIN TORQUE OSCILLATOR WITH A RADIO FREQUENCY CURRENT BIAS - A method to tune an oscillation layer frequency in a spin torque oscillator (STO) during a microwave assisted magnetic recording (MAMR) process is described. The STO oscillation layer (OL) has a large angle magnetization oscillation frequency that is locked to a magnetic medium bit resonance frequency f | 03-13-2014 |
20140240864 | STORAGE DEVICE HAVING DEGAUSS CIRCUITRY CONFIGURED FOR GENERATING DEGAUSS SIGNAL WITH ASYMMETRIC DECAY ENVELOPES - A hard disk drive or other storage device comprises a storage medium, a write head configured to write data to the storage medium, and control circuitry coupled to the write head. The control circuitry comprises degauss circuitry coupled to or otherwise associated with one or more write drivers. The degauss circuitry is configured to generate an asymmetric degauss signal to be applied to the write head. The asymmetric degauss signal has a waveform with upper and lower decay envelopes that are asymmetric about a specified degauss current level, such as a substantially zero current level. | 08-28-2014 |
20140240865 | DYNAMICALLY CONTROLLING MAGNETORESITIVE BIAS - Magnetoresistive (MR) bias is dynamically controlled in a tape drive using a processor device. Median tape head amplitude is monitored during a calibration operation, as measured across all tracks of the tape head, against predetermined thresholds of the tape drive for determining if the median tape head amplitude is below the threshold value. Upon determining the median tape head amplitude is below the threshold value during the calibration operation, a reference MR bias and a MR bias range is dynamically adjusted, during the calibration operation, for increasing the median tape head amplitude. | 08-28-2014 |
20140368946 | IN SITU SENSOR BASED CONTACT DETECTION - A method for detecting a contact event between a transducer and a recording medium is disclosed. The method includes positioning a transducer with respect to a recording medium, where the transducer includes a writer, a reader, a heater, and a thermally responsive sensor. The method further includes applying power to the heater to establish a fly height of the transducer; supplying a bias current through the thermally responsive sensor to generate a bias signal; measuring a root mean square (RMS) voltage V | 12-18-2014 |
20150131178 | MAGNETIC DATA ERASER - The magnetic data eraser includes: a mounting and immobilizing tray on which a magnetic recording medium is mounted, the mounting tray being inclined at an angle of 60±10 degrees to the horizontal; a magnetizer that is encircled by a magnetizing coil, the magnetizer having a hollow portion into which the mounting and immobilizing tray is inserted; and a controller that causes an electric current to flow as an excitation current through the magnetizing coil, the excitation current generating a magnetic field that erases data stored in the magnetic recording medium. | 05-14-2015 |
20160019923 | RESISTIVE TEMPERATURE SENSORS FOR IMPROVED ASPERITY, HEAD-MEDIA SPACING, AND/OR HEAD-MEDIA CONTACT DETECTION - A sensor supported by a head transducer has a temperature coefficient of resistance (TCR) and a sensor resistance. The sensor operates at a temperature above ambient and is responsive to changes in sensor-medium spacing. Conductive contacts connected to the sensor have a contact resistance and a cross-sectional area adjacent to the sensor larger than that of the sensor, such that the contact resistance is small relative to the sensor resistance and negligibly contributes to a signal generated by the sensor. A multiplicity of head transducers each support a TCR sensor and a power source can supply bias power to each sensor of each head to maintain each sensor at a fixed temperature above an ambient temperature in the presence of heat transfer changes impacting the sensors. A TCR sensor of a head transducer can include a track-oriented TCR sensor wire for sensing one or both of asperities of the medium. | 01-21-2016 |
20160163337 | MAGNETIC STACK INCLUDING COOLING ELEMENT - Various embodiments of a magnetic stack are disclosed. In one or more embodiments, the magnetic stack includes first and second shield layers, and a magnetically responsive lamination disposed between the first and second shield layers. The magnetically responsive lamination can be configured to receive a sense current I | 06-09-2016 |