Abstract: A method and apparatus for compensating for repeatable runout using wide embedded runout correction fields is provided. In one embodiment, a disk surface is provided with a write head associated therewith. The disk surface has a data track having a width. An embedded runout correction (ERC) field is written onto the disk surface, wherein the ERC field has a width that is greater than the width of the data track.

Abstract: A magnetic disk can be magnetized simply and in a short time. A magnetic disk producing method produces a magnetic disk having a central hole, an outer radius, a plurality of annular recording tracks formed in a direction from the central hole toward the outer radius, each recording track including a plurality of sectors, and a recess formed between adjacent recording tracks to a predetermined depth. The method includes providing a magnetizing master disk magnetized in a predetermined pattern of alternating N and S polarities extending in a direction from a center of the master disk toward an outer radius thereof; and superposing the master disk on the magnetic disk to magnetically transcribe a magnetic signal to the recording tracks based on the predetermined pattern.

Abstract: A perpendicular media recording (PMR) servo track writer (STW) system and method for writing servo sectors onto a disk is disclosed. The servo writer includes a head positioner to position a head of a head disk assembly (HDA) relative to a disk, wherein the head writes servo sectors onto the disk with a perpendicular flux. The servo writer includes a controller to control the head positioner such that the head writes servo sectors onto the disk from one of an inner diameter (ID) or an outer diameter (OD) of the disk to a middle diameter (MD) of the disk, respectively, followed by writing servo sectors between the other of the OD or the ID of the disk to the MD of the disk, respectively.

Abstract: A plurality of HDDs 12-1˜12-n connected around a host 10 can be made to directly communicate with each other. For example, an HDD 12-1 makes another HDD to perform long distance seek using this communication line and measures the influence of vibration caused at that time. The measurement result is formed into a transfer function indicating the position change of the head of the relevant HDD against the operation of another HDD. An HDD is actually driven by a current value obtained by correcting the normal driving current of the driving motor of the head by the transfer function.

Abstract: An information reproduction system that provides an apparatus for reproducing audio/video information from an information recording medium having a tape form for example and circumventing problems associated with illegal copies of information recording media. If a match is found between the contents of identification data information read from a memory fixed to a cassette incorporating a magnetic tape and the contents of individual key data information stored in an information storage memory, a controller causes an information reproducing block to reproduce main information from the magnetic tape.

Abstract: Embodiments of the present invention employ differential acceleration computations for detecting free fall conditions. The differential acceleration computations can be based on two-axis or three-axis acceleration measurements, and therefore can be implemented using a two-axis accelerometer or a three-axis accelerometer (or combinations of accelerometers that enable acceleration measurements in two or three axes). When a free fall condition is detected, an appropriate signal can be generated, for example, to place a HDD in a protected state before damage is likely to occur. Differential acceleration measurements can also be used to detect a “safe” condition following a free fall condition.

Abstract: Methods of controlling seeking of a transducer that is adjacent to a rotatable disk in a disk drive are disclosed. The methods may include accelerating the transducer radially across the rotatable disk from an initial track on the rotatable disk toward a destination track on the rotatable disk, estimating a deceleration switching position/velocity point, estimating a maximum deceleration position/velocity point following the deceleration switching position/velocity point, and estimating a deceleration current required to decelerate the transducer from a non-zero velocity at the maximum deceleration position/velocity point to zero velocity at the destination track. The estimated deceleration current is compared to a maximum available deceleration current, and responsive to a determination that the current required to decelerate the transducer from the maximum deceleration point to the destination track exceeds the maximum available deceleration current, the estimated deceleration switching point is adjusted.

Abstract: In an apparatus and a method for reproducing recorded signal related to this invention, a dynamic tracking head having two gaps, which deviate from each other traces a single track. Optimum dynamic tracking control is performed using track ID and a differential between envelope signals, which is a signal reproduced from the two gaps, and DC wobbling error. Thus, it controls the position of a reproducing head to a target track position.

Abstract: A disk drive includes a head and a disk, spiral patterns are located on the disk, and the disk drive self-writes servo patterns on the disk using the spiral patterns as a reference for servoing the head. In an embodiment, the disk drive uses preliminary servo patterns to determine repeatable runout of the spiral patterns. In another embodiment, the disk drive reads each spiral pattern with multiple timing windows.

Abstract: Attributes of data recorded on a magnetic tape are stored in an attribute information table saved in an MIC (Memory in Cassette) of a tape cassette accommodated in a tape streamer drive connected to a host computer. The attributes are recorded for every identifier used for identifying a recording unit of the data. For each identifier, the attributes include the name of a file, a title, a file creation date/time, a file updating date/time, the amount of data contained in the file, the type of the data and a compression rate of the data. The attributes include not only those supplied by the host computer but also attributes generated after a data recording operation as information on the recording location of data. The attributes generated after the data recording operation include a group number and an offset from the beginning of the group identified by the group number. For example, the present invention can be applied to the tape streamer drive.

Abstract: Embodiments of the invention provide a disk drive that is capable of effectively controlling a side erase, which is one of the problems with the use of the perpendicular recording technology. In one embodiment, tracks on a recording medium are formed concentrically or spirally by overwriting a primary side track, which is either an inner track or outer track, onto part of a secondary side track, which is on the side away from the primary side track. A head unit is installed so that a magnetic head positioned at one end of the head unit relatively may move over the recording medium and that the yaw angle prevailing at an end track of the primary side on the recording medium may be substantially zero.

Abstract: Hard Disk Drive (HDD) including a humidity sensor. Humidity sensor communicating with embedded circuit to provide humidity reading to alter flying height control asserted to control vertical positioning of slider above disk surface. Method operating HDD using humidity sensor and apparatus implementing method. Methods of manufacturing embedded circuit and HDD, and their products.

Abstract: A charge and discharge controller causes an capacitor to be charged by a power supply to a disk drive, and causes the capacitor to discharge when a power supply monitor detects the interruption of power to the disk drive. Upon detection of the interruption of power, an SPM controller supplies a current to an SPM using the discharge of the capacitor. Upon detection of the interruption of power, a retract controller supplies a current to a VCM using the discharge of the capacitor, thereby performing retract control for retracting the head to a ramp.

Abstract: Selection of servo signals for peak detection of timing based servo tracks of magnetic tape for lateral positioning of heads relative to the magnetic tape. Servo signals from magneto-resistive servo read head(s) reading a magnetic tape are digitized by analog to digital converter(s); digital peak measurement apparatus is configured to sense the digital converter(s), and provide positive peak values and negative peak values of the digitized servo signals; and control apparatus is configured to determine the greater of the provided positive peak values or negative peak values, and select servo signals having the greater values for a servo channel. Servo apparatus is configured to respond to the selected servo signals to control the lateral positioning of the servo read head(s).

Abstract: A disk drive is disclosed comprising a disk having top and bottom surfaces, and top and bottom heads actuated over the top and bottom surfaces, respectively. Control circuitry detects a warping of the disk by writing a first test pattern to the top surface, reading the first test pattern to generate a first read signal, monitoring a first read signal value proportional to an amplitude of the first read signal, writing a second test pattern to the bottom surface, reading the second test pattern to generate a second read signal, monitoring a second read signal value proportional to an amplitude of the second read signal, and processing the first and second read signal values to detect a negative correlation between the amplitudes of the first and second read signals.

Abstract: Slider used to access data on rotating disk in hard disk drive, including vertical micro-actuator forming piezoelectric layer perpendicular to air bearing surface and coupled to deformation region including read-write head. Slider further includes vertical control signal stimulating vertical micro-actuator to alter vertical position. The vertical control signal stimulates vertical micro-actuator to increase and decrease vertical position with potential differences of opposite sign. Flexure finger including vertical control signal path providing vertical control signal and micro-actuator assembly for coupling to slider. Head gimbal assembly including flexure finger coupled to the slider. A head stack assembly including at least one of the head gimbal assemblies coupled to a head stack. Hard disk drive including head stack assembly.

Abstract: A VCM power protection circuit that limits the maximum voltage that can occur across any of the VCM's output FETs, while at the same time providing some bias on a VCM output to direct a head toward a landing zone during power-up or any time there is a higher than normal voltage on the power supply.

Abstract: Embodiments of the invention provide optimum servo patterns for perpendicular magnetic recording method. In one embodiment, a burst field of servo patterns is composed of burst-signal parts in each of which a constant frequency occurs successively and zero-signal parts each of which has been demagnetized to a state of zero-magnetization, and the total magnetization of the burst field is made approximately 0. The zero signal portions are formed by shutting off a write current at a time during an operation to record servo patterns on a disk initialized to a state of zero-magnetization. The total magnetization of all servo patterns is made approximately 0 by encoding an address mark field and a track code field of servo patterns by a phase shift method.

Abstract: A fully synchronous servo channel for a data type drive is provided which includes the initial acquisition of synchronous servo channel parameters, generation of a timing basis for signal interpolation, generation of a tape velocity estimate and a y-position estimate and an optimum detection of longitudinal position (LPOS) symbols embedded in servo bursts.

Abstract: A portable wireless communication terminal includes a sensor to detect a movement of the portable wireless communication terminal and output a first signal based on an acceleration of the movement and a second signal based on a velocity of the movement and a controller to control a hard disk drive (HDD) in response to both the first and second signals.