摘要:
A disk device performs feedforward servo control for moving a head to a target track. The disk device includes a calibrating portion for updating feedforward information, for moving the head, into information dedicated to the specific disk device; and a feedforward information storing portion for storing the feedforward information.
摘要:
A disk storage device includes at least one disk, a head for scanning a principal surface of the disk in a generally radial direction thereof for reproducing a servo control signal in response to a servo pattern that is recorded on the principal surface, a rotary mechanism for moving the head along the principal surface of the disk generally in the radial direction, an amplifier supplied with the servo signal reproduced at the head for amplifying the same with a predetermined gain, a signal processing circuit for extracting first and second positional control signals each having a phase that is offset with respect to the phase of the other positional control signal by 90 degrees, from the servo control signal, a level detection circuit for detecting a head position at which the first and second positional control signals have simultaneously an identical level and further for detecting the level of the first and second positional control signals at the detected head position, a gain control circuit for controlling the gain of the amplifier such that an absolute value of the foregoing level is set to a predetermined value, and a head position control circuit for controlling a driving circuit in response to a combination of the first and second positional control signals, the head position control circuit locating the head on a predetermined recording track based upon a head position in which the first and second positional control signals have the same level simultaneously.
摘要:
In a disk medium, as servo patterns for offset detection, a pattern which is offset to the inner side, a pattern which is offset to the outer side, and a polarity pattern of a size exceeding a width of pattern as necessary are recorded in the track direction at specific cylinder positions of each data surface. In the case where only one of the read signals of the patterns which are offset to the inner side and outer side is obtained, the head is returned in such a direction as to eliminate the offset, and an offset measuring section measures the offset again. In this case, the offset measurement value is set to the total value of the head return amount and the last offset amount obtained from the read signals V1 and V2. When both of the two pattern read signals V1 and V2 are not obtained, the presence or absence of the read signal of the polarity pattern is judged. When the read signal of the polarity pattern exists, the head is offset to the side opposite to the polarity pattern by a predetermined amount and the offset is again measured. When the read signal of the polarity pattern doesn't exist, the head is offset by only the predetermined amount to the side on which the polarity pattern is not recorded and the offset is subsequently measured again.
摘要:
A disk drive unit includes acceleration sensors mounted thereon. A sequence for calculating an amount by which a head actuator is adjusted during recording and readout operations is changed based on an output from the acceleration sensors.
摘要:
A magnetic disk unit has two actuators each rotating on a common rotary shaft. The two actuators are driven by a voice coil motor. The voice coil motor comprises: a magnetic circuit comprising a magnet provided for the two actuators on a common basis and two yokes, which are associated with the two actuators, respectively, said two yokes being disposed at both sides between which the magnet intervenes; and two coils provided for the two actuators, respectively.
摘要:
Disclosed is a calibration method for an acceleration sensor in a storage device for calibrating and a storage device, an enclosure for calibrating the acceleration sensor for compensating a vibration of an enclosure in a state of its being mounted in a storage drive. The calibration method and mode comprises a step of exciting a actuator of the drive by flowing a drive current having a predetermined current value, a step of calculating the acceleration of the enclosure of the drive from the predetermined current value and a mechanical transfer function of the storage device, a step of detecting a measured value of the acceleration sensor, and a step of calculating a sensitivity of the acceleration sensor from the calculated acceleration and from the detected measured value. The acceleration sensor is calibrated in the state of its being mounted in the disk drive, and hence the sensitivity can be precisely calibrated.
摘要:
There is used a disk medium in which tracks are divided into a plurality of zones in the radial direction and information is read and written with a constant linear density by using a clock signal of a different frequency every zone. A drive unit forms a dead space corresponding to at least one track at a zone boundary of the disk medium and reads or writes the information. In the case where it is judged that the head passes through the zone boundary by the seeking operation to the cylinder address position instructed from an upper apparatus, the cylinder address instructed from the upper apparatus is corrected on the basis of the number of boundary passing times and the seeking operation is performed.
摘要:
A head exchange system for a disc drive system for controlling the position of a head so as to cancel, during a head exchange, the previously measured offset value between the head and a track of a recording disc. The head exchange system has a head exchanger for selecting one of a plurality of heads in response to a signal from the host controller for storage of the information to the selected track of the disc. The head exchange system also has a busy signal transmitting unit for transmitting, when changing the selected head, a busy signal to the host controller for a predetermined time when a difference between the offset value for a current selected head and the offset value for a next selected head is bigger than a predetermined value. The busy signal transmitting unit has a busy table for storing a plurality of flag information between each head and the other heads and transmits a busy signal to the host controller when the difference between the offset value for the current selected head and the offset value for the next selected head is bigger than the predetermined value.
摘要:
The present invention relates to an information recording medium for a disk drive having improved recording efficiency. The information recording medium is provided with discrete servo and data areas, with servo information being recorded in the servo areas. Cylinder information included in one or more servo areas is used to locate particular data areas on a disk. In the present invention at least partial cylinder information in one servo area is used to locate more than one data area by dividing the cylinder information into different servo areas, or using the cylinder information in one servo area to locate a data area associated with another servo area. By recording the divided cylinder information in respective ones of the servo areas provided on a given cylinder on the disk, less disk space is needed for cylinder information, so the size of the data areas can be increased and recording efficiency can be improved.
摘要:
There is provided a technique capable of eliminating the need to create data for compensating the displacement of a servo pattern occurring at the time of writing the servo pattern using an amplitude method and thereby of significantly reducing the production time of a disk medium.A servo pattern writing apparatus that uses a write head to write a servo pattern on a recording medium according to an amplitude method, comprises: a position sensor 8 that detects the displacement amount of the write head with respect to its reference position in the track crossing direction; and a delay amount adjustment circuit 10 that writes a servo pattern in correspondence with a servo pattern write phase amount which is set for compensating the displacement amount detected by the position sensor 8 at the time of demodulation of the servo pattern.