摘要:
Disclosed is a data storage device to provide servo patterns of a track pitch individually consistent with head characteristics (writing width, and reading width) in a recording medium of a hard disk device. The data storage device is provided with a disk having pitch information indicating a track pitch recorded in a predetermined area, and a head for scanning the disk to read the TPI ID and reading/writing data from/in the disk by being subjected to seeking control based on the TPI ID. The TPI ID is recorded as a part of a servo pattern in a TPI ID embedded area provided in an outer periphery of a data area of the disk.
摘要:
The invention relates to a method for writing servo patterns on a data recording disk of a disk drive device. A read/write head is stopped at a reference position on the data recording disk, then the read/write head is moved along a radial direction of the data recording disk from the reference position, then a determination is made as to whether the data recording disk has a sufficient width along the radial direction to write a predetermined number of servo tracks, or not, then the servo patterns are written on the servo tracks if the data recording a disk has the sufficient width.
摘要:
Embodiments in accordance with the present invention ensure that the pitch of a servo write track is accurately controlled. According to one embodiment of the present invention, a Self Servo Write (SSW) uses different methods and sequences to identify read-write offsets (RWOs) and calculate target positions in inner and outer diameter sides of a magnetic disk. In the inner diameter-side area, the SSW controller uses the readout of a radial pattern written on a recording surface and a reference value to identify the RWO. The SSW controller uses the RWO value identified in the inner diameter-side area to anticipate an RWO value in the outer diameter-side area. In the outer diameter-side area, the SSW controller uses the anticipated RWO value to determine the target position of each servo write track.
摘要:
Embodiments in accordance with the present invention control pitch variations that are not observed in self servo write (SSW). According to one embodiment of the present invention, an outer radius side area of a magnetic disk is erased using an external magnetic field, and an inner radius side area is subjected to self erase using a head. The magnetization state in the base of the inner radius side area is different from that of the outer radius side area before pattern writing. Therefore, in the inner radius side area and the outer radius side area, even if a radial pattern of the same pitch is read, the different APCs are measured. With SSW of this embodiment, a reference APC used in the inner radius side area is different from that used in the outer radius side area. In this manner, the pitch variation is prevented.
摘要:
In an embodiment of the present invention, with Self Servo Write (SSW), a head slider is used to perform AC erase to a recording surface of a magnetic disk. The AC erase is performed asynchronously to every track. A frequency for use with AC erase, i.e., a frequency of an AC erase pattern is three times or higher than a burst frequency of a product servo pattern or a burst frequency of a radial pattern. By satisfying such requirements, for the magnetic disk of vertical magnetic recording, it becomes possible to substantially stop adversely affecting pattern reading in an AC erase area.
摘要:
A disk drive. The disk drive includes a plurality of head-sliders, an actuator, a plurality of clearance adjustment sections, and a controller. Each head-slider includes a slider and a magnetic-recording head on the slider for accessing a disk for storing data. The plurality of head-sliders is secured to the actuator that is configured to move the plurality of head-sliders concurrently. Each clearance adjustment section corresponds to each head-slider of the plurality of head-sliders and adjusts a clearance of the corresponding head-slider. In addition, the controller is configured to position the actuator by servo control with a first head-slider selected from the plurality of head-sliders, to change a clearance of a second head-slider different from the first head-slider by controlling a clearance adjustment section of the second head-slider to bring the second head-slider into contact with a disk, and to detect the contact to measure the clearance of the second head-slider.
摘要:
A disk drive. The disk drive includes a plurality of head-sliders, an actuator, a plurality of clearance adjustment sections, and a controller. Each head-slider includes a slider and a magnetic-recording head on the slider for accessing a disk for storing data. The plurality of head-sliders is secured to the actuator that is configured to move the plurality of head-sliders concurrently. Each clearance adjustment section corresponds to each head-slider of the plurality of head-sliders and adjusts a clearance of the corresponding head-slider. In addition, the controller is configured to position the actuator by servo control with a first head-slider selected from the plurality of head-sliders, to change a clearance of a second head-slider different from the first head-slider by controlling a clearance adjustment section of the second head-slider to bring the second head-slider into contact with a disk, and to detect the contact to measure the clearance of the second head-slider.
摘要:
Embodiments of the present invention provide a method for manufacturing a magnetic disk unit, the method permitting easy and efficient introduction of a low-density gas into the enclosure. According to one embodiment, an enclosure of the magnetic disk unit has a gas inlet and a gas outlet, each of which is provided with a filter. When the enclosure is filled with helium, the mass flow rate of helium being supplied to the gas inlet is detected and the mass flow rate of helium being supplied to the gas inlet is controlled according to the thus detected mass flow rate of helium.
摘要:
Embodiments in accordance with the present invention ensure that the pitch of a servo write track is accurately controlled. According to one embodiment of the present invention, a Self Servo Write (SSW) uses different methods and sequences to identify read-write offsets (RWOs) and calculate target positions in inner and outer diameter sides of a magnetic disk. In the inner diameter-side area, the SSW controller uses the readout of a radial pattern written on a recording surface and a reference value to identify the RWO. The SSW controller uses the RWO value identified in the inner diameter-side area to anticipate an RWO value in the outer diameter-side area. In the outer diameter-side area, the SSW controller uses the anticipated RWO value to determine the target position of each servo write track.