Abstract: A library apparatus includes an accessor robot and a flat cable connected to the accessor robot. The flat cable has an outer check line and an inner check line each formed of a conductor. Breaks in each of the outer check line and the inner check line are detected to identify wear on the flat cable, and prevent sudden failure of the library apparatus.

Abstract: An integrated circuit servo system demodulator that incorporates a high speed gain stage with DC offset cancellation. The gain stage receives a differential voltage signal representing a servo burst and converts the differential voltage signal to a differential current signal by a transconductance amplifier. The differential current signal is full-wave current rectified and converted to a full-wave rectified voltage signal by a transimpedance amplifier. A DC offset cancellation circuit is coupled between the full-wave current rectifier and transimpedance amplifier and functions to mirror and subtract, from the rectified current signal directed to the transimpedance amplifier, any DC leakage current developed by the rectifier which would generate a DC offset voltage through the transimpedance amplifier.

Abstract: A disk drive and method which efficiently stores zone parameter sets for a plurality of disk surfaces. The disk drive includes a disk control system and a plurality of disk surfaces. Each disk surface has an associated transducer head in communication with the disk control system for reading and writing data to the disk surface. Each disk surface is subdivided into a plurality of zones. Control parameters sets for each zone of a disk surface are stored in table. The disk drive further comprises a first disk surface and a second disk surface. A first zone parameter table is provided for the first disk surface. The first zone parameter table comprising a zone control parameter set for each zone of the first disk surface. A second zone parameter table is provided. The second zone parameter table includes a number of zone control parameter sets, wherein the zone control parameter sets and the second zone parameter table are not included in the first zone parameter table.

Abstract: A servowriter positioning apparatus for hard disk drives comprises an optical read head 2 for directing three focussed light beams on grating sections formed at the end of a grating member 1 connected to the servo write head(s) 3 in order to indicate the position and movement of the head(s) 3. The optical read head 2 may be based on CD or DVD technology. The servo write head(s) 3 are mounted on an actuator arm 5 to which the grating member 1 is fixed for rotation therewith and which are both driven in rotation by a rotary actuator. The grating member 1 comprises two grating sections 11,12 separated by a smooth section 13 for generating a focus error correction signal. The apparatus of the invention can be used to sense and control the position and movement of the servo write heads, or of the read/write heads of the hard disk themselves, thus eliminating the need for any servo pattern.

Abstract: A technique for reading data from a magnetic disk includes the steps of providing the magnetic disk including a cylinder having a plurality servo sectors, a plurality of data sectors, and a zone data table, the plurality of servo sectors including a first servo sector, a second servo sector, a third servo sector, a fourth servo sector, and a fifth servo sector, the zone data table including at least a nominal timing latency between the fourth servo sector and a data sector from the plurality of servo sectors, reading the first servo sector, the second servo sector, the third servo sector, and the fourth servo sector from the magnetic disk, determining a first timing deviation for the first servo sector between the first servo sector and the second servo sector, determining a second timing deviation for the second servo sector between the second servo sector and the third servo sector, predicting a predicted third timing deviation for the fourth servo sector between the fourth servo sector and the fifth servo

Abstract: A disk drive includes a voice coil motor (VCM) and a VCM power source circuit which is coupled to a standard power supply having a fixed voltage. During seek operations the VCM power source circuit provides a boosted voltage, greater than the fixed supply voltage, for the VCM. The VCM power source circuit provides the boosted voltage independently from the back EMF generated in the voice coil motor. The increased VCM voltage allows faster access times and more efficient VCM operation.

Abstract: A servo system uses a disk on which two pairs of burst data items A and B and burst data items C and D are prerecorded, and the servo system performs positioning control for positioning a head within a range of a track on a disk. The servo system sets a range of a track to be divided into a first area regarding the track center as a reference position, a second area regarding a boundary position between tracks as a reference position, and a third area regarding a middle position between the reference positions, as a reference position. In the first area, the servo system calculates position information of the head by a first calculation formula using the burst data items A and B. In the second area, the servo system calculates position information of the head by a second calculation formula using the burst data items C and D. Further, in the third area, the servo system calculates an average value of calculation results from the first and second calculation formulas, as position information.

Abstract: A magnetic recording and reproducing apparatus has a supply reel and a take-up reel around which a magnetic tape is to be wound. A first tape guide is provided in the vicinity of a rotary head at the supply reel side and a second tape guide in the vicinity of the rotary head at the take-up reel side. The first and second tape guides are movable in directions of a width of the magnetic tape. A detector detects a height of each of the first and second tape guides. A count value corresponding to the detected height of at least either the first or the second tape guide is obtained by a counter. The height of at least either the first or the second tape guide is adjusted so that the count value becomes equal to a reference value. The count value is set to a specific value when the detected height becomes a reference height corresponding to the reference value after the magnetic tape has been wound around the supply and take-up reels.

Abstract: A storage disk apparatus has a storage disk having servo information, a plurality of heads for reading information recorded on the storage disk, a plurality of first actuators for accurately positioning the heads with respect to the storage disk, a second actuator for coarsely positioning the heads with respect to the storage disk, and a control circuit for controlling the first actuators and the second actuator according to the servo information read by one of the heads. The control circuit supplies a drive current value depending on the servo information read by one of the heads to one of the first actuators to position the one of the heads, and also supplies the drive current value to the other first actuators to position the other heads. When one of the heads is positionally detected, all the first actuators, typically microactuators, are prevented from being vibrated and relatively displaced from the second actuator in a seek mode.

Abstract: A magnetic storage device is disclosed. The magnetic storage device contains a magnetic media. Previously recorded information resides on tracks in the magnetic media. A transducer is used to read information from the magnetic media. The transducer includes a first read element and a second read element. The first and second read elements are both laterally and longitudinally offset from each other. A method of reading information stored on a track of a magnetic media is also disclosed. Information is read from the magnetic media using the first and second read elements to produce respective first and second analog read signals. The first and second analog read signals are an electrical representation of the information previously recorded on the track.

Abstract: A recording apparatus for a multitrack longitudinally extending record carrier records information by moving forward and reverse along various tracks in successive sub portions of the record carrier in a serpentine manner. This makes it possible to quickly access a desired portion of a recorded motion picture simply by changing tracks instead of having to wait until all intervening portions of the motion picture have been scanned. The apparatus is thus well suited to multimedia recording.

Abstract: The invention relates to a magnetic recording device which can be used at a reduced atmospheric pressure without having the head/slider assembly stick to the disk. A method of the present invention for controlling the operation of a disk drive device in reduced atmospheric pressure where a read/write head mounted on a head support arm flies above the surface of a rotating recording disk. The head support arm is moved along a radial direction of the recording disk to position the read/write head to one of cylinder positions of the recording disk.

Abstract: An apparatus that compensates for the asymmetry and the baseline shift in the signal generated by a magnetoresistive head. The apparatus stores a first correction factor for the baseline shift, a second correction factor for correcting the amplitude of the positive portion of the signal and a third correction factor for correcting the amplitude of the negative portion of the signal. The first correction factor for correcting for baseline shift is added to the signal generated by the magnetoresistive head to generate a baseline corrected signal. The baseline corrected signal is then monitored for positive and negative excursions from the baseline and the positive excursions are multiplied by the second correction factor and the negative excursions are multiplied by the third correction factor for generating a compensated signal.

Abstract: A method in a magnetic storage disk drive for independently learning and thereafter canceling repeatable runout that is written to the servo fields of each servo track during the servo writing process. The method does not require a servo writer because the disk drive may independently detect the runout without spinning out of control in response to such runout by operating its servo control loop in a low bandwidth mode so that it is less responsive to the higher frequency components of the runout, and by removing the effect of the DC component of the runout or selected harmonics on each revolution.The method takes several revolutions to "learn" the servo wedges of a current track by initializing a wedge runout value for each servo wedge and an average uncorrected runout value and then successively developing an interim wedge runout estimate for each servo wedge by adding a fractional portion .lambda. of a raw position error signal to a fractional portion (1-.lambda.

Abstract: A write operation to a magnetic recording medium (10) is performed by supplying a predetermined write current to a write head (1) from an R/W signal processing portion (2) through a head composite signal processing portion (3), and a rewrite operation is performed by supplying a rewrite current having a value different from that of the predetermined write current to the magnetic head (1) by supplying a write current having a value different from the predetermined write current under a control of a hard disk controller (6) when an abnormality is detected by a head abnormality detection circuit (5) in the write operation with the predetermined write current. When an abnormality is further detected by the head abnormality detection circuit (5), the data write is judged as abnormal.

Abstract: The present invention provides a disk drive, a load/unload unit, and a control method thereof which are capable of reliably unloading a head slider from a disk when power is turned off and enhancing reliability. A disk drive is equipped with a VCM spindle driver for rotating a disk, a magnetic head, an actuator mechanism for moving over the surface of the magnetic disk or to an evacuating position a head slider having the magnetic head, a ramp block, and a CPU/HDC (control means) for performing control of load and unload operations, speed control of the actuator mechanism, and control of an operation of reading or writing data from or to the disk. The CPU/HDC receives a specific command issued from the host immediately before power is turned off, and executes this command, then executes unload control, and notifies the host of command completion after the unload control has been completed.

Abstract: Virtual tracks are set so that the rotation center of a magnetic recording medium or the vicinity of the rotation center coincides with the track center of the data information, and positioning servo control is performed. Thus, since it is not necessary to faithfully follow the track center line specified by the servo information that is previously recorded on the magnetic recording medium or magnetooptical recording medium, a vibration is not easily caused in synchronism with the rotation. Therefore, when the rotation center and the pattern center are deviated from each other, since a vibration is not caused in synchronism with the rotation, the magnetic head of the magnetic recorder or the magnetooptical head of the magnetooptical recorder is able to follow tracks with higher precision. Accordingly, the recording density can be increased.

Abstract: A disk drive system includes a base, a disk rotatably attached to the base, and an actuator assembly movably attached to the base. The actuator assembly moves the transducer to selected areas of the disk where information representative of data is to be written or read. The actuator assembly maintains the transducer in a transducing relationship with the disk. The actuator assembly also parks the transducer or unloads the transducer to a park position. A portion of the actuator assembly rides over a ramp to a park position. The ramp includes a mechanism for varying the coefficient of friction on the surface of the ramp. The ramp has a lower coefficient of friction when the actuator is unloading the transducer from the disk. When the actuator is placed in a park position, the coefficient of friction on the surface of the ramp is increased to help retain the actuator in its parked position.

Abstract: A method used to implement a sampled servo control system in a magnetic disk drive for generating a fractional track portion of a position error signal to correctably maintain the alignment of a read transducer (or associated write transducer) relative to a centerline of one of a plurality of a concentric data tracks upon a rotating data storage disk. The system uses a hybrid approach of determining a fractional track position by using a two-burst algorithm when possible and using a multi-burst algorithm only when necessary. The system is particularly suited to determining fraction track position when jogging a relatively narrow magnetoresistive read transducer with a servo pattern normally useful only for wider transducers, namely a pattern of four angularly sequential servo bursts A, B, C, D that are 100% of a track pitch in width and are arranged in quadrature.

Abstract: An information storage medium has at least a longitudinal bundle comprising three servo tracks (3, 4, 5). The bundle is arranged in consecutive tracking units (T(N)) of a determined longitudinal length. Surfaces of said servo tracks present either a first or a second characteristic (6, 7) and vary in size and distribution inside the tracking units. The bundles may contain longitudinally stored identification information. Methods for obtaining tracking signals indicating a transversal offset between a reading head and the bundle and for retrieving identification information are disclosed. Also methods for obtaining tracking units in which transversal tracking code is combined with distinct information are described.