| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 360780010 | Track changing | 64 |
| 20080212229 | Method of and apparatus for detecing actuator vibration in hard disc drive, and hard disc drive write control method of avoiding effect due to read/write head vibration - A method of and an apparatus for detecting an actuator vibration, and a hard disc drive write control method of avoiding an effect due to the actuator vibration. The method of detecting an actuator vibration includes: obtaining a specified number of position error signal (PES) samples while following a track; performing a time-frequency conversion on the specified number of PES samples; and detecting a magnitude of a conversion coefficient indicating a magnitude of an actuator vibration, in a specified frequency band. | 09-04-2008 |
| 20090190251 | DATA RECORDING METHOD - A recording method for a disk device includes the following steps. Sequential data is written into the medium along the track in a predetermined radial direction. Information indicating an end position along the track where the end of the sequential data is written into is stored. The information is read when additional sequential data is to be written into the medium. The additional data is written from a position along the track next to the end position indicated by the information in the predetermined radial direction. The information is updated so as to indicate an end position along the track where the end of the additional sequential data is written into. | 07-30-2009 |
| 20100039728 | METHOD OF DETECTING POSITION OF HEAD AND STORAGE APPARATUS - A relative movement is induced between a head and first and second recording tracks along the boundary between the first recording track and the second recording track. The first recording track includes first magnetic dots arranged in the down-track direction at constant intervals. The second recording track includes second magnetic dots arranged in the down-track direction at constant intervals identical to the intervals of the first magnetic dots. The second magnetic dots are dislocated in the down-track direction relative to the first magnetic dots. The positional information is generated to specify the position of the head based on the difference between a first output of signals read from the first magnetic dots and a second output of signals read from the second magnetic dots. | 02-18-2010 |
| 20120063028 | MAGNETIC RECORDING APPARATUS - According to one embodiment, there is provided a magnetic recording apparatus including a bit-patterned medium having a data area including magnetic dot rows each of which includes magnetic dots, a magnetic head having a width covering a plurality of magnetic dot rows, and an actuator configured to actuate the magnetic head in a cross-track direction. The magnetic dots included in a n-th magnetic dot row have a higher coercivity than the magnetic dots included in a (n+1)-th magnetic dot row. | 03-15-2012 |
| 360780020 | Tape | 4 |
| 20100033869 | APPARATUS AND METHOD FOR WRITING DATA ON A TAPE MEDIUM - An apparatus and method are disclosed for writing data accumulated in a buffer on a tape medium in such a way that overwriting is prevented. The apparatus comprises a write unit configured for writing first data in a first position extending over a first track and an area adjacent to the first track, writing second data in a second position extending over a second track and an area adjacent to the second track, and writing the first data and the second data in a third position extending over a third track and an area adjacent to the third track. Furthermore, the apparatus comprises a processing unit configured for preventing the first data written in the first position from being overwritten with the second data written in the second position or with the first data written in the third position. | 02-11-2010 |
| 20100202083 | SETTING EDGE STRESS SIGNAL IN MAGNETIC TAPE DATA STORAGE CARTRIDGE MEMORY IN RESPONSE TO SERVO DETECTION ERROR SIGNALS - Methods, magnetic tape data storage drives, data storage systems, and magnetic tape data storage cartridges. A system having at least one magnetic tape data storage drive is configured to handle a magnetic tape cartridge comprising a magnetic tape data storage media and accompanying cartridge memory. The magnetic tape media comprises a plurality of longitudinal servo bands, the servo bands separated by data bands. Two servo bands, each at opposite sides of a data band are sensed. In response to at least one servo detection error signal of one of the two servo bands, an edge stress signal is set to the cartridge memory of the magnetic tape cartridge. Then, for example, after reloading the cartridge, the cartridge memory is inspected for a set edge stress signal; and, if the edge stress signal is set, only read operations are allowed with respect to the inspected magnetic tape data storage cartridge. | 08-12-2010 |
| 20110102938 | POWER MODE OPERATION OF A MAGNETIC TAPE DRIVE - A magnetic tape drive having a tape drive system for moving magnetic tape, tape read/write and servo system, tape cartridge load/unload systems, I/O communications, memory; and a control system, operates in three modes to conserve energy consumption. A first low power mode powers the I/O communications, the memory, and the control system. If a magnetic tape cartridge is in loaded position in the magnetic tape drive, the second low power mode powers the same as the first low power mode, and additionally powers the tape drive system to apply tension to a magnetic tape of the magnetic tape cartridge. In the first and the second low power modes, the control system operates the I/O communications, the memory and the control system to respond to and execute commands received at the I/O communications if the commands are executable without magnetic tape access. The third, full power mode, is entered if a command received at the I/O communications requires magnetic tape access. | 05-05-2011 |
| 20140204483 | SERVO CONTROL - In a method for operating a tape storage system, while a tape is being moved in a tape drive across a tape head for one or more of reading and writing user data from/to a data track of the tape, a read element of the tape head, which read element is assigned to the data track, is moved transverse to a moving direction of the tape for a distance of more than a width of the data track. A transverse position of one or more of the following elements is subject to a signal supplied by the read element during its transverse move: The read element; another read element assigned to the data track; and a write element assigned to the data track. | 07-24-2014 |
| 360780040 | For rotary carrier (e.g., disc) | 56 |
| 20080218898 | Head control device, storage device, and contact detection method - A head control device for controlling, through thermal expansion of a heater, a position of a head for reading and writing data from and to a storage medium, includes a heater control unit that increases a current supplied to the heater stepwise; and an external-force sample retrieving unit that retrieves sampling values of signals each indicating a magnitude of an external force acting on the head in a moving direction of a head support mechanism. The head control device also includes an external-force evaluating unit that calculates a representative value of the sampling values retrieved by the external-force sample retrieving unit to evaluate the magnitude of the external force every time the heater control unit increases the current; and a contact detecting unit that detects contact between the head and the storage medium by comparing each evaluation result by the external-force evaluating unit with a predetermined threshold value. | 09-11-2008 |
| 20090086366 | HARD DISK DRIVE OFF TRACK EVENT METHOD AND DEVICE - Methods and devices are shown that identify suitable second data operations after experiencing an off track event in a first data operation and perform the second data operations before correcting an off track event. Methods and device as shown provide increased efficiency in a hard disk drive. Time that normally would be wasted waiting for the read/write head to spin around for another try to correct an off track error is used to complete other nearby operations. | 04-02-2009 |
| 20090122442 | ANTICIPATORY TRACK SWITCHING - Various embodiments of the present invention are generally directed to using a transducer to transfer data during a transducer displacement operation at a time during such operation when the transducer is substantially stationary. | 05-14-2009 |
| 20090168232 | Microactuator reference input limit to prevent internal states over-accumulation - A microactuator reference limit used to prevent over-accumulation of internal states may be set based on the microactuator's mechanical properties and is applied at the reference point to the microactuator servo subsystem. A microactuator variable input limit to prevent over-accumulation of internal states may be dynamically determined based on the difference between a signal corresponding to the maximum physical stroke of the microactuator and an estimated motion of the microactuator. Either configuration of servo system automatically ensures that all the internal states of the microactuator controller will not over-react and cause excessive overshoot, sluggish response, and/or saturation. | 07-02-2009 |
| 20100007986 | SETTING WRITER BOUNDARIES FOR MULTIPLE WRITERS - A storage medium having a boundary located along a surface of the storage medium that functions as a transition point for selectively operating a first writer and a second writer of a plurality of writers, where the location of the boundary is set based on writing capabilities of the plurality of writers. | 01-14-2010 |
| 20100053802 | Low Power Disk-Drive Motor Driver - One embodiment of the invention includes a disk-drive motor control system. The system comprises a seek mode power supply configured to provide a first voltage corresponding to a seek mode associated with a disk-drive voice control motor (VCM). The system also includes a track mode power supply configured to provide a second voltage corresponding to a tracking mode associated with the disk-drive VCM. The first voltage can be greater than the second voltage. The system further includes a disk-drive motor driver configured to provide a current to the disk-drive VCM at a first magnitude in the seek mode based on the first voltage, at a second magnitude in the tracking mode based on the second voltage, and at a third magnitude in a head-retraction mode. | 03-04-2010 |
| 20100232057 | Techniques For Storing Shingle Blocks in a Cache Memory Using a Data Storage Device - A data storage apparatus includes a data storage medium, a write element, a non-volatile cache memory circuit, and a controller circuit. The controller circuit is configured to record data on the data storage medium in groups of overlapping tracks using the write element. The controller circuit is configured to store a shingle block of data from a subset of the overlapping tracks in the non-volatile cache memory circuit, while at least a portion of the data in the shingle block of data is updated. | 09-16-2010 |
| 20100232058 | INFORMATION RECORDING MEDIUM GLASS SUBSTRATE, INFORMATION RECORDING MEDIUM, INFORMATION RECORDING APPARATUS AND MANUFACTURING METHOD OF INFORMATION RECORDING MEDIUM GLASS SUBSTRATE - In an information recording apparatus such as a hard disk drive, a ramp for retreating its head from a recording medium when the apparatus is stopped is provided opposing the information recording medium. In such an information recording apparatus, the information recording medium may sometimes collide with the ramp when the apparatus falls down. By inclining a portion opposing the ramp of a glass substrate in the information recording medium, even if the information recording medium strikes the ramp, the information recording medium is prevented from being cracked. | 09-16-2010 |
| 20110026160 | SERVO PATTERN WRITING METHOD, CONTROL CIRCUIT, AND MAGNETIC DISK APPARATUS - According to one embodiment, a servo pattern writing method includes: moving a head from a first one of innermost and outermost circumferences of a medium to the remainder other than the first one while controlling a position of the head in accordance with a temporary pattern preliminarily written on the medium; calculating a junction between a servo pattern to be written from the innermost circumference and a servo pattern to be written from the outermost circumference based on a movement distance of the head; first writing the servo pattern from a second one of the innermost and outermost circumferences to the junction, while controlling the position of the head in accordance with the temporary pattern; and second writing the servo pattern from the remainder other than the second one to the junction, while controlling the position of the head in accordance with the temporary pattern. | 02-03-2011 |
| 20120069466 | APPARATUS OF MAGNETIC DISC - An object of the present invention is to further improve a recording density in a magnetic disk apparatus using a shingle write system. | 03-22-2012 |
| 20120194946 | INFORMATION RECORDING DEVICE AND INFORMATION RECORDING METHOD - According to one embodiment, an information recording device includes: a recording controller configured to control recording of information on a magnetic recording medium having tracks by a recording method; a managing module configured to manage two or more counters corresponding to each of plural track groups that are adjacent to each other; an updating module configured to update a count of one of the two or more counters corresponding to a second track group that is adjacent to a first track group of the plural track groups when information has been recorded on the first track group; a determining module configured to determine an attribute of the second track group based on the updated count of the one counter; and a rewriting module configured to rewrite information recorded in the second track group based on the determined attribute. | 08-02-2012 |
| 20120243119 | MAGNETIC DISK DRIVE HAVING MICROACTUATOR - According to one embodiment, a servo controller of a magnetic disk drive includes a microactuator (MA) estimator, VCM actuator (VCMA) controller, a filter and an adder. The MA estimator estimates a first displacement of an MA from a control input to be provided to the MA. The VCMA controller controls a VCMA based on a positioning error between a target track and a first position of the VCMA. The first position is estimated from a position of a head and the first displacement. The filter estimates a second position of the VCMA corresponding to a delay in a displacement of the MA caused by hysteresis of the MA, from a state of the VCMA in a seek operation, and estimates a second displacement that is the delayed displacement of the MA, from the second position. The adder adds the second displacement to an input to the MA controller. | 09-27-2012 |
| 20130135768 | PATTERNED MAGNETIC RECORDING DISK FOR MULTI-TRACK RECORDING WITH COMPENSATION FOR HEAD SKEW, AND MASTER TEMPLATE FOR NANOIMPRINTING THE DISK - The invention is a patterned-media disks for multi-track recording that are fabricated by nanoimprinting from a master template and that have data islands arranged in a pattern to compensate for head skew. The islands are arranged along lines canted relative to a disk radial line by an acute angle, as required for multi-track recording. However, this angle is not the same for all bands, but varies from band to band to compensate for head skew. The angle the lines in a band are canted is reduced by the amount of head skew. There are a plurality of bands between the disk inside-diameter (ID) and mid-diameter (MD) where the angle is in one direction from a radial line and a plurality of bands between the disk MD and outside-diameter (OD) where the angle is in the opposite direction from a radial line. | 05-30-2013 |
| 20130222944 | Adaptive Seek Latency - The disclosure is related to systems and methods for adaptive seek latency in a rotating storage device. In one example, a servo control circuit can be configured to determine a seek latency and provide the seek latency to another controller or control circuit that is configured to implement the seek latency. Further, the servo control circuit can calculate the seek latency based on a measurement of a variable condition of a device and the servo controller can adjust the seek latency as the condition varies. In some examples, the variable condition may include power measurements, temperature measurements, a fault rate, other conditions, or any combination thereof. Also, different algorithms for calculating the seek latency may be implemented based on a selected goal of the system, such as power savings or reduced head vibration. | 08-29-2013 |
| 20130329316 | MICROWAVE ASSISTED MAGNETIC RECORDING HEAD AND MAGNETIC DATA STORAGE APPARATUS - To suppress a spread of not only a recording magnetic field generated from a main pole but also a high-frequency magnetic field generated from a spin torque oscillator in a microwave assisted magnetic recording head. The main pole and the spin torque oscillator are surrounded by a trailing shield layer and are also surrounded by a side/leading shield layer with an insulator sidegap layer interposed therebetween, and a high-frequency magnetic field shield layer, which absorbs a high-frequency magnetic field generated from the spin torque oscillator, is arranged in at least part of the shield layers. | 12-12-2013 |
| 20130329317 | Magnetic Recording Head and Magnetic Recording Apparatus - An example magnetic writing head includes a main magnetic pole and a coil to generate an ampere magnetic field to magnetize the main magnetic pole to cause the magnetized main magnetic pole to generate a magnetic field. The laminated body includes a first magnetic layer, and a second magnetic layer. | 12-12-2013 |
| 20140036387 | MICROWAVE ASSISTED MAGNETIC RECORDING HEAD HAVING SPIN TORQUE OSCILLATOR, AND MAGNETIC RECORDING APPARATUS - To provide a spin torque oscillator which is adapted to high data transfer rates and which can perform assisted magnetic recording of sufficient magnitude. A spin torque oscillator is provided with a stacked spin injection layer and a high frequency magnetic field generation layer. The stacked spin injection layer has a stacked structure in which a first magnetic layer, a coupling layer, and a second magnetic layer are stacked in the order mentioned from a far side as viewed from the high frequency magnetic field generation layer. Magnetization of the first magnetic layer and magnetization of the second magnetic layer are coupled antiparallel to each other. A polarity of the magnetization of the second magnetic layer is reversed temporally earlier than a magnetic field polarity reversal of a leakage magnetic field from the main magnetic pole. | 02-06-2014 |
| 20140177095 | SPINDLE MOTOR AND HARD DISK DRIVE INCLUDING THE SAME - There is provided a spindle motor, including: a shaft having a fixing groove formed in a lower portion thereof; a lower thrust member including a fixing part inserted into the fixing groove, a disk part extending from the fixing part in an outer radial direction, and an extension part extending from the disk part in an axial direction; a base member coupled to the extension part; a rotating member forming a bearing clearance with the shaft and rotatably provided with respect to the shaft; a first sealing part provided between an upper surface of the extension part and the rotating member; and a second sealing part provided between an inner circumferential surface of the base member and an outer circumferential surface of the rotating member. | 06-26-2014 |
| 20140177096 | BASE ASSEMBLY AND RECORDING DISK DRIVING DEVICE HAVING THE SAME - There is provided a base assembly including: a base member having a disk accommodating part onto which a disk is insertedly disposed; and a filter member installed on the base member so as to be disposed adjacently to the disk, wherein the base member is formed by performing plastic processing on a steel sheet and includes a mounting part for fixedly installing the filter member. | 06-26-2014 |
| 20140293477 | SPINDLE MOTOR AND HARD DISK DRIVE INCLUDING THE SAME - There are provided a spindle motor and a hard disk drive including the same. The spindle motor includes a sleeve fixedly installed on a base member and including a circulation hole formed in an axial direction; a shaft rotatably inserted into the sleeve; a rotor hub fixedly installed on an upper end portion of the shaft; and a thrust member installed in an installation groove formed in an upper portion of the sleeve in the axial direction and forming a connection part allowing the circulation hole to be in communication with a sealing part formed by the sleeve and the rotor hub and having a liquid-vapor interface, wherein the connection part is formed between the sleeve and the thrust member in a circumferential direction, and a gap on any one side of the connection part in a radial direction is larger than a gap on the other side thereof. | 10-02-2014 |
| 20140293478 | SPINDLE MOTOR AND HARD DISK DRIVE INCLUDING THE SAME - There are provided a spindle motor and a hard disk drive including the same. The spindle motor includes: a sleeve installed on a base member and having a circulation hole; a shaft inserted into the sleeve; a rotor hub installed on an upper end portion of the shaft; and a thrust member installed in an installation groove formed in an upper portion of the sleeve and forming a connection part, the connection part allowing the circulation hole to be in communication with a sealing part formed by the sleeve and the rotor hub and having a liquid-vapor interface disposed therein, wherein the connection part is formed between the sleeve and the thrust member in a circumferential direction, and at least any one part of the connection part has a radial gap wider than that of another part thereof in the circumferential direction. | 10-02-2014 |
| 20140313612 | SPINDLE MOTOR AND HARD DISK DRIVE INCLUDING THE SAME - There are provided a spindle motor and a hard disk drive including the same. The spindle motor includes: a sleeve supporting a shaft so that an upper end of the shaft protrudes upwardly in an axial direction and a bearing clearance filled with a lubricating fluid formed between the sleeve and the shaft; a housing provided so as to enclose an outer peripheral surface of the sleeve and forming a circulation hole between the housing and the sleeve in the axial direction; and a rotor hub fixedly installed on an upper end portion of the shaft in the axial direction, wherein a connection part is formed between the housing and the rotor hub so as to allow a sealing part on which a liquid-vapor interface is disposed and the circulation hole to be in communication with each other. | 10-23-2014 |
| 20150092297 | PROTECTION OF A MAGNETIC DISK UNIT ON A PORTABLE COMPUTING DEVICE - A portable computing device prevents a magnetic disk unit protecting function from impairing usability for a user when the processor is used as a tablet PC. The portable computing device includes a magnetic disk unit, a magnetic disk unit protecting section operable when predicting an occurrence of an impact to carry out a magnetic disk unit protecting function for retracting a head of the magnetic disk unit, and a detecting section that detects whether a user is holding the portable computing device or not, and responsive to detecting that the user is holding the portable computing device, temporarily deactivating the magnetic disk unit protecting function. | 04-02-2015 |
| 20150364149 | ENLARGED SUBSTRATE FOR MAGNETIC RECORDING MEDIUM - An enlarged substrate for a magnetic recording medium used in a data storage device such as a hard disc drive (HDD). In some embodiments, an apparatus includes a substrate for a magnetic recording disc for installation in a 3- 1/2 inch form factor hard disc drive, the substrate having an overall diameter of nominally from 96.9 mm to 100.4 mm. In other embodiments, an apparatus comprises a substrate for a magnetic recording disc for installation in a 2- 1/2 inch form factor hard disc drive, the substrate having an overall diameter of nominally from 66.9 mm to 71.8 mm. In other embodiments, a data storage device has a magnetic recording medium that uses an enlarged substrate as set forth above. | 12-17-2015 |
| 20160104504 | DATA STORAGE DEVICE GENERATING AN OPERATING SEEK TIME PROFILE AS A FUNCTION OF A BASE SEEK TIME PROFILE - A data storage device is disclosed comprising a head actuated over a disk comprising a plurality of tracks. An operating seek time profile is generated as a function of a base seek time profile, wherein the seek time profiles define a seek time to seek the head radially over the disk by a seek length. A seek operation is executed to seek the head by a target seek length by at least generating a target seek time based on the target seek length and the operating seek time profile, and seeking the head the target seek length based on the target seek time. | 04-14-2016 |
| 20160111114 | Self-Cleaning Recording Heads Based On Actuator Seek Profile - Cleaning a recording head slider in-drive during operation is accomplished by periodically performing a series of full stroke seek operations, whereby liquid contaminants that may have migrated to the head slider are flung from the slider and liquid from the disk surface may be adsorbed onto the slider for removal by way of flinging. Consequently, head-disk spacing may be stabilized and data write operations improved. Furthermore, the series of full stroke seek operations may be performed at predetermined intervals, and for a predetermined period of time. However, the series may be interrupted by a client request, and continued thereafter, so as not to affect the operational status of the recording system. | 04-21-2016 |
| 20160118072 | Enlarged Substrate for Magnetic Recording Medium - An enlarged substrate for a magnetic recording medium used in a data storage device such as a hard disc drive (HDD). In some embodiments, a data storage device has a housing member for a 3½ inch form factor storage device or a 2½ inch form factor storage device. A rotatable data recording disc is supported by the housing member. The disc has a plurality of tracks formed thereon. At least one track of the plurality of tracks has an average radius of greater than 47.5 mm for the 3½ inch form factor storage device or greater than 32.5 mm for the 2½ inch form factor storage device. A data read/write transducer is configured to be controllably advanced across a recording surface of the data recording disc and to record data to the plurality of tracks. | 04-28-2016 |
| 20160125902 | MAGNETIC DISK DEVICE AND CONTROL METHOD - According to one embodiment, there is provided a magnetic disk device including a casing, a seek mechanism, and a controller. The seek mechanism is attached to the casing and configured to make a magnetic head seek a target track on a magnetic disk. The controller is configured to feedback-control the seek mechanism so as to reduce a reaction force acting on the casing during an acceleration period of seek by the seek mechanism. | 05-05-2016 |
| 20160140990 | MAGNETIC DISK DEVICE AND METHOD OF CONTROLLING MAGNETIC DISK DEVICE - According to one embodiment, a method of controlling a magnetic disk device, includes acquiring a retry rate indicating a ratio of the number of retries to the number of seeks for a seek distance selected in a seek operation related to a read operation and a write operation, and adjusting a predicted seek time for the selected seek distance based on the acquired retry rate. | 05-19-2016 |
| 360780050 | Coarse and fine head drive motors | 3 |
| 20080259491 | Magnetic disk drive - Embodiments of the present invention help to provide a magnetic disk drive that is capable of reducing a time period necessary for positioning a magnetic head when positioning the magnetic head by use of a dual-stage actuator. According to one embodiment, a main control circuit of a magnetic head device selects one of a seek mode and a positioning mode. The seek mode is to set a coarse adjustment control system to be a stable system by not causing control of a piezoelectric actuator to be performed by a fine adjustment control circuit. The positioning mode is to set the coarse adjustment control system to be an unstable system and setting a total control system inclusive of the coarse adjustment control system and a fine adjustment control system to be the stable system by causing the control of the piezoelectric actuator to be performed by the fine adjustment control circuit. Thereby the main control circuit causes the control system to operate. | 10-23-2008 |
| 20130135769 | MAGNETIC HEAD INSPECTION APPARATUS AND MAGNETIC HEAD INSPECTION METHOD - In inspection for a magnetic head having a built-in fine-motion actuator, stable servo control is realized without an effect of thermal drift or thermal expansion. A magnetic head inspection apparatus includes a fine-motion stage, a data process circuit, and a servo control circuit. The fine-motion stage performs positioning of a magnetic head in a predetermined position on a magnetic disk. The data process circuit measures the movement characteristic of the fine-motion actuator. The servo control circuit controls the magnetic head to track the servo track on the magnetic disk based on a measurement result of the data process circuit. The servo control circuit drives the fine-motion stage, and controls the magnetic head to move in a manner that the value of movement of the fine-motion actuator remains within an acceptable range. | 05-30-2013 |
| 20150062748 | MOTOR POLARITY TESTING OF A DUAL STAGE ACTUATED DISK DRIVE HEAD SUSPENSION - Methods and apparatus concern testing a disk drive suspension. Testing includes moving a first portion of a suspension relative to a second portion. A pair of motors is mounted on the suspension. The testing further includes measuring an electrical signal that is intrinsically produced by the motors, combined in a circuit, in response to the relative movement. The testing further includes identifying a characteristic of the electrical signal and determining whether an orientation of one or both of the motors is reversed relative to an intended motor orientation based on the characteristic of the electrical signal. The testing can determine whether the orientation of both motors matches the intended motor orientation, whether the orientation of one motor is reversed in a same polarity condition, whether the orientations of both motors are reversed in a mutual reverse polarity condition, or whether the suspension has a mechanical or electrical defect. | 03-05-2015 |
| 360780060 | Specified velocity pattern during access | 11 |
| 20080218899 | Quiet high performance seek procedure for disk drives - a seek procedure for a hard disk drive which provides a significant reduction in acoustic noise as well as high performance fast seek times is described. The seek procedure lowers the peak acceleration for short seeks and imparts a smooth transition from a sine seek to an exponential arrival at the target track. The seek procedure provides an error free feedforward signal derived from a single sine table. The procedure which contains a time domain sinusoid acceleration feedforward combined with a phase-plane trajectory controlled velocity which, near seek completion. The procedure is constructed so that the acceleration begins at zero and, in the fashion of a sine, increases to a maximum, decreases to a minimum and then increases again until a computed switchpoint is reached. The switchpoint is determined in-situ, to provide a smooth and continuous velocity transition from sinusoid to exponential. The velocity trajectory is computed from a look-up table. The procedure is implemented using conventional seek controller servo components and commercially available operation software. | 09-11-2008 |
| 20080291568 | MAGNETIC DISK APPARATUS AND METHOD FOR CONTROLLING MAGNETIC HEAD - A magnetic disk apparatus includes: a driving unit; a position error feedback control system; and a velocity control system. The driving unit is configured to move a magnetic head operative for magnetic recording/reproduction of information on a magnetic disk. The position error feedback control system is configured to perform feedback control of the driving unit based on difference between target track position and detected position of the magnetic head. The velocity control system is configured to vary a target velocity curve based on position of the magnetic head before motion, the target track position of the magnetic head, and position of a data sector to be subjected to recording/reproduction, for using a control mathematical model of the driving unit to control the driving unit so that velocity of the driving unit follows the target velocity curve. | 11-27-2008 |
| 20090034116 | STORAGE APPARATUS, CONTROL METHOD, AND CONTROL DEVICE - A rotation disturbance compensation control unit applies a compensation signal to a positioning control unit so as to cancel out rotation disturbance vibration components detected by using acceleration velocity sensors. At predetermined timing, a position error detection unit detects respective position errors of the case in which the rotation disturbance compensation control unit is turned on and the case in which it is turned off. A compensation control switching unit switches the rotation disturbance compensation control unit to be on if the position error of the case in which the compensation control of rotation disturbance is turned on is small and switches the compensation control switching unit to be off if the position error of the case in which the compensation control of rotation disturbance is turned off is small. | 02-05-2009 |
| 20090034117 | STORAGE APPARATUS, CONTROL METHOD, AND CONTROL DEVICE OF STORAGE APPARATUS - A seek control unit moves a head to the vicinity of a target track of a storage medium by coarse control, then switches it to fine control, and positions the head to the target track. A rotation disturbance compensation control unit applies a rotation disturbance vibration detection signal based on acceleration velocity sensors to the seek control unit as a compensation signal so as to cancel out rotation disturbance vibration components. A compensation control switching unit sets the rotation disturbance compensation control unit to be either on or off and, when a coarse seek error in which it is out of a fine switch error range upon coarse control by the seek control unit is finished is determined, switches the rotation disturbance compensation control unit to an opposite setting state and causes the seek control unit to perform seek again. | 02-05-2009 |
| 20090109567 | SEEK CONTROL APPARATUS AND METHOD FOR GENERATING CONTROL DATA FOR SEEK CONTROL - There is provided a method for generating acceleration data used in feed-forward control of head seeking, wherein, a seek distance and one of a seek period and the count of samples are received; a weighting factor for the change rate of acceleration between adjacent sample times is determined respectively; and an optimum acceleration at each sample time is obtained by performing an optimization calculation that minimizes an objective function under a constraint condition based on variables representing accelerations at each sample time, either the seek period or the count of samples, and the seek distance. | 04-30-2009 |
| 20110090591 | SEEK CONTROL METHOD TO AVOID FLEX CABLE RESONANCE DURING SETTLE IN HARD DISK DRIVE - A hard disk drive with a circuit that can perform a seek routine by providing a seek current to a voice coil motor. The voice coil motor is coupled to a head that is coupled to a disk. The seek current provides a predetermined number of harmonics. The number of harmonics is a function of a seek length of the seek routine. By way of example, the seek current may include only a first harmonic for seek lengths less than 20,000 tracks, or only the first and second harmonics for seeks less than 40,000 tracks. The harmonics can be determined by plotting PES settle versus seek length for a hard disk drive. | 04-21-2011 |
| 20120281311 | RAMP-UNLOADING SEEK CONTROL DEVICE FOR MAGNETIC DISK DRIVE - A ramp-unloading seek control device includes a voice coil motor, a detector, an instruction-current detector, a head-speed computing unit, and an identification structure. The identification structure estimates an error between a true resistance value and an estimated resistance value of the voice coil motor. The identification structure can minimize an estimated error defined as a difference between an estimated value ŷ(k) of the head speed and the head speed y(k), and employs {circumflex over (b)} | 11-08-2012 |
| 20130038962 | DISK DRIVE DECREASING A SETTLE DELAY BASED ON SPEED THAT A SETTLE PARAMETER ADAPTS - A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of tracks, and control circuitry operable to seek the head to a target track and settle the head on the target track during a settle time, adapt a settle parameter used to settle the head on the target track, access the target track after an access delay, and decrease the access delay based on a speed that the settle parameter adapts. | 02-14-2013 |
| 20140063651 | SUPPRESSION OF SEEK REPEATABLE RUNOUT - The disclosure is related to an apparatus and methods of suppressing seek repeatable runout. In a particular embodiment, a servo loop is disclosed. The servo loop includes a seek signal generation component that generates a seek trajectory acceleration signal. The servo loop also includes a STRRO suppression component that is coupled to the seek signal generation component. The STRRO suppression component injects STRRO suppression signals into the seek trajectory acceleration signal and outputs an STRRO suppressed seek trajectory acceleration signal. | 03-06-2014 |
| 20140320999 | DISK DRIVE MINIMIZING INITIAL SEEK DISTANCE AFTER LOAD OPERATION - A disk drive is disclosed comprising a disk comprising tracks defined by servo sectors, a head, and control circuitry comprising a servo control system operable to actuate the head over the disk in response to the servo sectors. The head is loaded over the disk during a load operation, and a radial velocity of the head is determined during the load operation. A target track is generated based on the determined radial velocity of the head, and the servo control system seeks the head to the target track. | 10-30-2014 |
| 360780070 | Controlled by memory device | 1 |
| 20110205664 | INFORMATION STORING DEVICE AND METHOD FOR CONTROLLING SAME TO RECORD/REPRODUCE INFORMATION BY SELECTING ONE OF WORKING MODES - An information storing device and an information processing device having a memory for registering a plurality of working modes at recording/reproduction and a switching circuit for selecting one of the plurality of working modes, which select the optimum working mode automatically or by an instruction of an operator according to power supply capacity of a device of higher rank to effect recording/reproduction. | 08-25-2011 |
| 360780080 | Specified spatial pattern during access | 1 |
| 20140300991 | MAGNETIC DISK APPARATUS AND CONTROL METHOD OF MAGNETIC HEADS - A seek control section is configured so that when a magnetic head is within a prescribed range from a zone boundary when there is a head change request, the magnetic head is driven to seek in a stable region, and then the magnetic head is changed from a current head to a target head. After the change from the current head to the target head, the target head is driven to seek the target position. | 10-09-2014 |
| 360780090 | Including model of servo system or element | 3 |
| 20100079906 | Adaptive Feed Forward Rotational Vibration Compensation During a SEEK Operation - A disk drive assembly includes a disk drive, one or more accelerometers, a control circuit, and an adaptive feed forward circuit. The one or more accelerometers generate acceleration signals that are used to detect rotational vibration (RV) events on the disk drive. The control circuit is configured to: generate one or more control signals, which are based on a control signal from a host system and a compensation signal from the adaptive feed forward circuit, and generate a position error signal (PES) that indicates an error in a position of a disk drive head relative to a center of a track. The adaptive feed forward circuit generates the compensation signal, which compensates for the detected RV events based on the acceleration signals and the PES. The compensation signal accounts for self-induced RV events generated by a SEEK operation that repositions the head to a new track, wherein feed forward adaption is not disturbed by the SEEK operation. | 04-01-2010 |
| 20100142086 | METHOD AND APPARATUS FOR CONTROLLING THE EFFECTS OF SEEK-INDUCED VIBRATION OF A COMPONENT PART IN A HARD-DISK DRIVE - A method for controlling the effects of seek-induced vibration of a component part in a hard-disk drive. The method includes determining a resonant frequency of seek-induced vibration of the component part and a reference amplitude of a frequency-component in a first voice-coil-motor signal (VCMS) at the resonant frequency. The method also includes synthesizing a second VCMS with an amplitude of a frequency-component attenuated below the reference amplitude of the frequency-component in the first VCMS at a frequency in a resonance-band bracketing the resonant frequency. The method also includes driving a voice-coil of a voice-coil motor with the second VCMS to reduce an amplitude of a frequency-component at the resonant frequency in a second PES of the seek of the data track associated with the second VCMS below a reference amplitude of a frequency-component at the resonant frequency in the first PES associated with the first VCMS. | 06-10-2010 |
| 20140198407 | MAGNETIC DISK DEVICE AND METHOD OF CONTROLLING MAGNETIC HEADS - According to one embodiment, a magnetic disk device includes: magnetic heads; a magnetic disk in which servo patterns having different write frequencies from one another are divided and recorded into a plurality of zones; and a head controller configured such that, when performing seek control of the magnetic heads based on a model position and a model velocity obtained from a model which simulates the magnetic heads, the head controller corrects the model position and the model velocity, at the time of switching of the zones, so as to reflect variation of sampling time resulting from gaps between the zones. | 07-17-2014 |
| 360780120 | Including particular head actuator | 4 |
| 20080225431 | Multi-Arm Disk Drive System Having Interleaved Read/Write Operations and Method of Controlling Same - A hard disk drive system that includes one or more rotating data storage platters, a drive controller and multiple actuator assemblies and corresponding respective read/write heads. The actuator assemblies are separately moveable for performing separate data seeks. The controller is configured to interleave the seek and read/write operations of the multiple actuator assemblies and read/write heads with one another. | 09-18-2008 |
| 20090015962 | HEAD-DISC INTERFACE (HDI) MODAL RESPONSE MONITORING - Apparatus and method for head-disc interface (HDI) modal response monitoring. A sensing element disposed on a rigid actuator arm is mechanically impedance matched to a head-disc interface (HDI) supported by the actuator arm to resonate at a predetermined frequency corresponding to at least one disturbance associated with the HDI. | 01-15-2009 |
| 20090128950 | High aspect ratio motion limiter of a microactuator and method for fabrication - A high-aspect ratio motion limiter of a microactuator and a method for fabrication are disclosed. In one embodiment, at least one low-aspect ratio gap is created in a substrate of a microactuator of a hard disk drive. The low-aspect ratio gap is then utilized to facilitate the creation of a high-aspect ratio motion limiter in the substrate of the microactuator. | 05-21-2009 |
| 20110002066 | ACTUATOR ARM AND DISK RECORDING DEVICE - According to one embodiment, an actuator arm includes a joint, an extension, a pair of outer surfaces, and a linear protrusion. The joint is rotatably supported on a shaft. The extension extends from the joint and has a tip end connected to a head that performs at least reading or writing with respect to a rotating disk recording medium. The outer surfaces are in a front-and-rear relationship with each other. At least one of the outer surfaces faces the disk recording medium. The linear protrusion is arranged on and extends along an edge of at least one of the outer surfaces. The edge is located upstream on the outer surfaces in a flowing direction of an air flow generated by the rotation of the disk recording medium. | 01-06-2011 |
| 360780140 | By recorded servo reference or address signal | 5 |
| 20130033783 | MULTI-DIRECTIONAL SELF SERVO-WRITING FOR A DISK DRIVE - A method of self servo-writing servo information to a plurality of disk surfaces in a disk drive that includes writing servo information to a plurality of disk surfaces in a first direction, writing servo information to a plurality of disk surfaces in a second direction, and determining an amount of overlap to be written on a reference surface with the reference head that will produce an overlap of servo information on each of the surfaces in the disk drive to which servo information is to be written. The method also includes switching to different tables when seeking across the overlap or border areas. | 02-07-2013 |
| 20130120873 | DISK DRIVE UPSAMPLING SERVO CONTROL SIGNAL - A disk drive is disclosed comprising a disk including a plurality of servo tracks, wherein each servo track comprises a plurality of servo sectors. The disk drive further comprises an actuator for actuating a head over the disk in response to an actuator control signal. The servo sectors are read to generate a first sequence of control samples x[k] at a sample rate corresponding to a frequency of the servo sectors. The first sequence of control samples x[k] is upsampled by a factor of N to generate a second sequence of control samples y[k | 05-16-2013 |
| 20140153131 | DISK STORAGE APPARATUS AND METHOD FOR SERVO CONTROLLING - According to one embodiment, a disk storage apparatus includes a servo system. The servo system includes a state observer and performs a seek operation up to a target position with a current position of a head undetermined. The servo system performs the seek operation based on initial values including a temporary position, while allowing the state observer to operate based on the initial values, until the current position is determined. The servo system determines the current position based on the servo data read from the plurality of servo areas by the read module and a result of estimation by the state observer. | 06-05-2014 |
| 20140340788 | Magnetic Storage Medium Comprised of Magnetic Nanoparticles Contained Within Nanotubes - A magnetic storage medium is formed of magnetic nanoparticles that are encapsulated within nanotubes (e.g., carbon nanotubes). | 11-20-2014 |
| 20150116863 | ADAPTIVE GUARD BAND FOR MULTIPLE HEADS OF A DATA STORAGE DEVICE - An adaptive guard band scheme is disclosed for a data storage device. In illustrated embodiments, the adaptive guard band scheme formats different guard band cylinders and track zeros for different heads depending upon a contact cylinder of the different heads. In an illustrative embodiment, the adaptive guard band scheme utilizes the contact cylinders for the heads and a no fly cylinder to determine track zero(s) and extended data zone(s) for select heads. | 04-30-2015 |
