Abstract: According to one embodiment, the controller of the magnetic disk drive configured to synthesize the first positioning data and second positioning data obtained by the second reader reading the positioning information based on the evaluation data, and performs positioning of the magnetic head based on the synthesized positioning data.

Abstract: According to one embodiment, the controller of the magnetic disk drive configured to synthesize the first positioning data and second positioning data obtained by the second reader reading the positioning information based on the evaluation data, and performs positioning of the magnetic head based on the synthesized positioning data.

Abstract: According to one embodiment, a magnetic disk device includes a first magnetic disk, a second magnetic disk, a first actuator with a first head which reads/writes data from/to the first magnetic disk, a second actuator with a second head which reads/writes data from/to the second magnetic disk, the second actuator operated independently from the first actuator, a first controller configured to retracts the first actuator at a first time, and a second controller configured to retract the second actuator at a second time which is shifted from the first time by a certain period of time.

Abstract: According to one embodiment, a magnetic disk device includes a first magnetic disk, a second magnetic disk, a first actuator with a first head which reads/writes data from/to the first magnetic disk, a second actuator with a second head which reads/writes data from/to the second magnetic disk, the second actuator operated independently from the first actuator, a first controller configured to retracts the first actuator at a first time, and a second controller configured to retract the second actuator at a second time which is shifted from the first time by a certain period of time.

Abstract: A method for correcting a mounting position of a disk device on a rack, includes performing a normal seek to position a head of the disk device above a target position on the disk, determining that the normal seek has failed, and performing an excitation seek that causes a position of a base supporting the disk to move and reposition the disk. The disk device includes a carriage arm supporting the head, a voice coil motor configured to drive the carriage arm to position the head, the base supporting the magnetic disk, the voice coil motor, and the carriage arm, and a control unit configured to control a current to the voice coil motor to be supplied with a first current profile during the normal seek and with a second current profile during the excitation seek.

Abstract: A method for correcting a mounting position of a disk device on a rack, includes performing a normal seek to position a head of the disk device above a target position on the disk, determining that the normal seek has failed, and performing an excitation seek that causes a position of a base supporting the disk to move and reposition the disk. The disk device includes a carriage arm supporting the head, a voice coil motor configured to drive the carriage arm to position the head, the base supporting the magnetic disk, the voice coil motor, and the carriage arm, and a control unit configured to control a current to the voice coil motor to be supplied with a first current profile during the normal seek and with a second current profile during the excitation seek.

Abstract: According to one embodiment, a method of writing servo information comprises: moving a head at a predetermined pitch in the radial direction of a storage disk to write servo information to each radial direction position in the circumferential direction of the storage disk; detecting a positional deviation value of the head while the servo information is being written to the radial direction position and determining whether the positional deviation value exceeds a predetermined value; and writing, when the positional deviation value exceeds the predetermined value, the position of defective servo information where the positional deviation value exceeds the predetermined value to a predetermined position in the radial direction of the storage disk.

Abstract: A operation of storing a post code, which is read from each servo frame on a target track of a disk recording medium, in a memory if an on-track condition for determining that a head is controlled to be positioned on the target track is satisfied is executed. Next, a operation of using the post code, which is stored in the memory, for a correction of a demodulation position if the post code corresponding to each servo frame is stored in the memory and the on-track condition is satisfied in the correction of the demodulation position in each servo frame is executed.

Abstract: An information storage apparatus includes a disc-shaped recording medium in which control marks aligned in a predetermined rule are recorded, a head contacting or approaching a recording medium surface to reproduce/record information of the recording medium and detecting the control marks, a head driving section holding the head to move the head in a direction of coming near or away to/from a recording medium rotation center, a driving force control section controlling a driving force for head driving section, a driving time control section controlling a driving time for the head driving section using an interval of the detection of the plural control marks as a time unit, and a driving force correcting section obtaining a difference between an ideal interval based on the rule of the control marks and an actual interval of the control marks to correct the control of the driving force based on the difference.

Abstract: A operation of storing a post code, which is read from each servo frame on a target track of a disk recording medium, in a memory if an on-track condition for determining that a head is controlled to be positioned on the target track is satisfied is executed. Next, a operation of using the post code, which is stored in the memory, for a correction of a demodulation position if the post code corresponding to each servo frame is stored in the memory and the on-track condition is satisfied in the correction of the demodulation position in each servo frame is executed.

Abstract: A fault detection circuit, for detecting a fault condition associated with a sensor (wherein non-fault detection signals output by the sensor include high frequency noise components), includes: an input unit to receive a raw signal from the sensor and to provide a corresponding detection signal; and a determination unit to determine if the detection signal includes components in significant amounts corresponding to the non-fault high frequency noise components, and to output an indication that the fault condition is satisfied if the detection signal does not include components in significant amounts corresponding to the non-fault high frequency noise components.

Abstract: A magnetic disk incorporated into a magnetic disk device is divided radially into a plurality of areas. An inner-circumference area has servo information written thereon at a low frequency. An outer-circumference area has servo information written thereon at a high frequency. The magnetic disk device creates concentric tracks on the magnetic disk with a magnetic disk rotation center as the center of the concentric tracks and selects a dividing track that acts as a demarcation for switching the area from which servo information will be read. The magnetic disk device then deletes all the servo information that is not going to be read in each of the areas divided by the dividing track.

Abstract: To reduce power consumption of an information storage device, a control circuit for the information storage device stops the supply of a formatter clock or an ECC unit clock simultaneously with a seek operation. When a clock stop time has elapsed by the time obtained by subtracting at least a time required for restarting the formatter or the ECC unit from a seek time, the control circuit restarts the supply of the formatter clock or the ECC unit clock.

Abstract: Upon recording, a clearance control unit performs preheating by an added control value (BR) of a base heater control value B and an adjustment heater control value R and switches that to value B when it reaches a target sector to perform write. Upon reproduction, preheating is performed by the value (BR) and the value (BR) is maintained when it reaches a target sector to perform read. A correction processing unit detects contact between the head and a medium surface while increasing the value R from a predetermined initial value Ro, and sets a new calculated base heater control value B, and value Ro as the adjustment heater control value R. Write assist adjustment in which the measured adjustment heater control value R is adjusted to a heater control value that improves characteristic deterioration immediately after recording is started wherein preheating is switched to write heating is performed.

Abstract: A seek control apparatus for performing a seek control of a head comprises an MCU that acquires control information corresponding to the externally indicated data length out of the control information stored in a storage section storing the control information for seek control for each of a plurality of data length ranges and performs a seek control according to the acquired control information.

Abstract: Upon recording, a clearance control unit performs preheating by an added control value (B+R) of a base heater control value B and an adjustment heater control value R and switches that to merely the base heater control value B when it reaches a target sector so as to perform write. Upon reproduction, preheating is performed by the added control value (B+R), and the added control value (B+R) is maintained when it reaches a target sector so as to perform read. A correction processing unit 46 detects contact (touchdown) between the head and a medium surface while gradually increasing the adjustment heater control value R from a predetermined initial value Ro, sets a value, which is obtained by subtracting a heater control value Sp converted from a minimum clearance and the initial value Ro from a contact heater control value Rtd, as the base heater control value B, and sets the initial value Ro as the adjustment heater control value R.

Abstract: A seek control apparatus, a seek control method and a storage apparatus can prevent degradation of performance of a read/write head due to residual oscillations in a seek operation. The seek control apparatus for performing a seek control of a head comprises an MCU 11 that acquires control information corresponding to the externally indicated data length out of the control information stored in a storage section 18 storing the control information for seek control for each of a plurality of data length ranges and performs a seek control according to the acquired control information.

Abstract: A magnetic disk incorporated into a magnetic disk device is divided radially into a plurality of areas. An inner-circumference area has servo information written thereon at a low frequency. An outer-circumference area has servo information written thereon at a high frequency. The magnetic disk device creates concentric tracks on the magnetic disk with a magnetic disk rotation center as the center of the concentric tracks and selects a dividing track that acts as a demarcation for switching the area from which servo information will be read. The magnetic disk device then deletes all the servo information that is not going to be read in each of the areas divided by the dividing track.

Abstract: In an apparatus for recording and/or reproducing information, which reproduces servo information being recorded on a medium and conducts a tracking operation based on the servo information, a power save part conducts a power save operation by reducing an operation clock frequency in accordance with a predetermined process during a tracking operation, during a seek operation, and/or during spindle motor startup.

Abstract: A recording apparatus capable of securely reading out data for causing a head to follow along circular tracks set virtually. Therefore, on-track control along the virtual tracks is possible by the conversion data on the discoid record medium even when, for example, the printed circuit board in a recording apparatus has been replaced.