104 results about "Track density" patented technology

A method and apparatus is disclosed for adjusting the track density over the disk radius by changing the slope of spiral tracks used to servo write a disk drive. A plurality of spiral tracks are written to the disk wherein each spiral track comprises a high frequency signal interrupted at a predetermined interval by a sync mark. A slope of the spiral tracks over a first radial segment of the disk is substantially steeper than the slope of the spiral tracks over a second radial segment of the disk. The head internal to the disk drive is used to read the spiral tracks in order to write product servo sectors to the disk to define a plurality of data tracks. The steeper slope of the spiral tracks over the first radial segment causes a track density of the data tracks to be lower over the first radial segment compared to the track density of the data tracks over the second radial segment.

A disk drive is disclosed comprising a head actuated over a disk. A redundancy generator generates a plurality of redundancy symbols appended to user data to form a codeword C(x) written to a selected data sector on the disk. During a read operation, a syndrome generator generates a plurality of error syndromes in response to a received codeword C′(x) generated by reading the selected data sector. An error detector, responsive to the error syndromes, detects a number of errors in the received codeword C′(x), and a plurality of counters count a number of times the number of errors falls within a predetermined plurality of ranges to thereby provide a distribution of the errors. The error distribution is used, for example, for selecting a track density or ECC depth, or for failure prediction or defect mapping.

A method and apparatus is disclosed for adjusting the track density by changing the slope of spiral tracks used to servo write a disk drive. A target track density is established for a disk surface, and a plurality of spiral tracks are written to the disk surface in response to the target track density. Each spiral track comprises a high frequency signal interrupted at a predetermined interval by a sync mark, and a slope of the spiral tracks is selected in response to the target track density. The head internal to the disk drive is used to read the spiral tracks in order to write product servo sectors to the disk to define a plurality of data tracks, wherein the slope of the spiral tracks determines the density of the data tracks.

Disclosed is a control system for processing sampled servo data in a disk drive. The control system includes a microprocessor and a servo processing accelerator circuit for performing operations on the sampled servo data while the microprocessor is executing firmware code. The accelerator circuit supports the use of a higher servo bandwidth thus allowing a higher track density resulting a greater storage capacity for the disk drive. Also, the accelerator circuit relieves the microprocessor of the ordinary servo processing function. Thus, the microprocessor's limited processing capacity to be directed to other controller and interface functions of the disk drive. Only under unusual conditions, such as a write-unsafe (WUS) limit exception, does the microprocessor need to direct processing capacity to the servo processing function. Further, the accelerator circuit may be a decreased response time after reading the servo data from the disk.

Closer spacing of elements for writing multiple tracks onto a magnetic media increases the areal density of stored information. A thin film multiple track recording head includes recording gaps in a plane parallel with the head substrate. This configuration allows for flexible placement of the elements within the head, improved control of recording gap geometry, and alternating azimuth gap angles.

Disclosed is a technique of providing a large-capacity magnetic storage device at high device manufacturing yield while keeping the reliability, the magnetic storage device enabling recording on a perpendicular magnetic recording medium having distribution of characteristics in the circumferential direction as well at high track density of 500 kTPI or more that would be expected from the average characteristics of the medium. A recording condition from is selected for each sector from a parameter table that stores a set of at least two types of recording conditions by a microwave assisted magnetic recording head including a magnetic recording pole and a high-frequency magnetic field oscillator in the magnetic storage device, and information is recorded for each sector based on the condition.

A magnetic recording system containing magnetic recording media with separate data and servo magnetic layers is disclosed. A servo magnetic layer resides usually below the data layer and has higher coercivity than that of the data layer. Interference between the data and servo signals is minimized by recording the servo patterns perpendicular or transverse direction with respect to the orientation of data bits. In addition, servo patterns are selected so that no interference with the data is generated by the servo pattern when the reader is in the middle of data tracks. Tracking error signals are approximately linear with track misregistration around the middle of data tracks. Finally, interference between the data and servo signals is further reduced by electronic processing. Continuous servo signals permit increased track densities with a single actuator and very high track densities with dual microactuator-actuator system.

A disk drive utilizes a track dependent variable write fault gate for each of the transducers within the drive. By deriving a 3 sigma distribution across the repeatable run out (RRO) and the non-repeatable run out (NRRO), a position error signal (PES) is derived which varies in magnitude across the stroke of the transducers and which has a slope used to derive variable write fault gate thresholds for the tracks associated with each transducer. As the stroke of the transducer moves from the outer diameter (OD) to the inner diameter (ID), the magnitude of the write fault gate thresholds may be decreased relative to the PES, and track density and capacity may increase where PES and write fault gate thresholds are low. The invention thus maintains a constant hard error recovery margin across the stroke.

The invention provides a method for extracting a target classic track in a complex environment. The method provided by the invention can realize extraction of the target classic track under complex conditions such as strong data randomness, loud noise, different track lengths and large point track interval difference of the target track, and is realized by the following technical scheme: reading target track data, prescreening according to value range constraints with different attributes in the track data, and removing abnormal data items; rasterizing latitude-longitude grids, counting the point track density in each latitude-longitude grid, and extracting all the track data and filtering the track data with relatively high point track density; clustering the filtered track data with a multi-distance threshold DBSCAN clustering algorithm to form a plurality of track clusters; and setting a scanning line for each cluster, sequentially calculating an average value of intersection pointsof the scanning lines and the track to obtain the point tracks in the target classic track, and connecting the point tracks in order to obtain a target classic track extraction result.

A hard disk drive with a disk that includes a first group of tracks and a second group of tracks. The second group of tracks are used to write large blocks of data. For example, data in the second group may be video or audio. The second group of tracks has a higher track density than the first group of tracks. The large data block is written sequentially in the second group of tracks so that there is only one adjacent track write within the group. Using only one adjacent track write allows the tracks within the second group to be overlapped to increase track density.

A rotational, shear mode, piezoelectric motor is integrated with a suspension, head or head gimbal assembly (HGA) into a collocated, rotational, shear mode, piezoelectric micro-actuated suspension, head or head gimbal assembly (HGA) for use in disk drives and disk drive manufacturing equipment. When excited by a control voltage, the collocated, shear mode, piezoelectric micro-actuated HGA rotates the head enabling high frequency, high resolution track positioning of the read/write element. The motor is integrated with the head and flexure (collocation). The head rotates about a rotation axis that is ideally located at the center of mass of the head. A shear mode piezoelectric motor rotates the head. A collocated, rotational, shear mode, piezoelectric micro-actuated HGA has high stiffness, high frequency response, high positioning resolution, low mass and low internal vibration for improved tracking, increased track density and greater disk drive storage capacity. Furthermore, its solid integration improves shock resistance and reduces micro-contamination.

The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. The head includes a main pole, a heavy metal structure surrounding at least a portion of the main pole at a media facing surface (MFS), and two magnetic structures sandwiching the heavy metal structure. Spin-orbit torque (SOT) is generated from the heavy metal structure, inducing magnetization switching (or precession) in the magnetic structures. The SOT reduces the magnetic flux shunting from the main pole to the trailing shield, and the magnetization switching sharpens the write field profile in the cross-track direction. The SOT based head with the magnetic structures sandwiching the heavy metal structure increases both track density (tracks per inch) and linear density (bit per inch), which in turn increases the areal density capability (ADC), which is the product of tracks per inch and bit per inch.

An information storage apparatus that records servo information and user data on a recording face of a recording medium wherein a track density measuring unit measures the optimal track density for a recording face corresponding to each head targeting a storage medium on which the servo information has not yet been recorded and a recording density measuring unit measures the optimal linear density for each recording face. A servo frame writing unit writes the servo information varying a track pitch to a track pitch corresponding to the optimal track density measured by the track density measuring unit and a recording frequency to a recording frequency corresponding to the optimal linear density measured by the linear density measuring unit, for each head.

A method and apparatus for optimizing data record quality on a disk for a pair of read and write heads, in which the write head is bigger, by adaptively varying linear and track density of overlapping recorded tracks to achieve a target storage capacity. In the method, target storage capacity and radial writing direction are selected. Read and write widths of heads are determined. A linear density and offset distance pairing for optimizing record quality at target storage capacity is determined, wherein offset distance is less than write width but greater than read width. The write head writes a track at the linear density, is offset in the radial direction by the offset distance, and the offset distance is stored. The write head writes a new track at the linear density. Offsetting, storing offset, and writing a new track are repeated until desired data is written into a cluster.

A method of defining storage format in a data storage device having a plurality of storage media and a plurality of corresponding data transducer heads, each transducer head for recording on and playback of information from a corresponding storage medium. A storage format is defined in at least one region on each storage medium, wherein each region includes a plurality of concentric tracks for recording on and playback of information. The method includes: moving each storage medium with respect to the corresponding transducer head and reading data from each storage medium with the corresponding transducer head; measuring a record/playback performance capability of each transducer head; selecting a group of track densities, one track density for each region on a storage medium, based on the measured record/playback performance capability of the corresponding transducer head.

A Hard Disk Drive VCM positioning servo loop comprises an oversampling bitstream Digital to Analog converter. The oversampling DAC is a sigma-delta converter which yields higher resolution and lower noise than Nyquist-rate DACs. This allows driving the VCM with finer level of current control for higher track density. This approach can be implemented in the VCM driver chip ("combo chip") or in the microprocessor device either in hardware or in software, reducing significantly the development and manufacturing cost. Furthermore this approach can be utilized in combination with a VCM actuation method known as "voltage mode drive" wherein the output of the sigma-delta converter represents the voltage to be applied directly to the VCM actuator. Furthermore this approach can be utilized for optical data storage motor positioning servo loops or any other motor positioning servo loops where high dynamic and resolution is needed.