According to one embodiment, a magnetic disk device including a disk, a head, and a controller configured to, when writing a first servo sector, a second servo sector, and a third servo sector in the order described according to a second route varying in a radial direction of the disk with respect to a first route, adjust first timing used to write the second servo sector next to the first servo sector, and adjust second timing used to write the third servo sector next to the second servo sector.

In a disk drive, when an off-track error occurs during a sequential disk access operation that spans multiple contiguous data tracks, efficient recovery is performed. In an embodiment, the disk access operation (e.g., reading from or writing to a disk) is attempted for all sectors of the sequential disk access operation. The disk access operation is then attempted again for sectors associated with any off-track errors that occurred during the disk access operation. In another embodiment, when an off-track error occurs during a sequential write operation in a shingled magnetic recording drive, the data originally targeted to be written to a first portion is written to a second portion of the data track that follows the first portion. Since no additional revolutions of the disk are needed for data associated with the sequential write operation to be written to the disk.

In a disk drive, when an off-track error occurs during a sequential disk access operation that spans multiple contiguous data tracks, efficient recovery is performed. In an embodiment, the disk access operation (e.g., reading from or writing to a disk) is attempted for all sectors of the sequential disk access operation. The disk access operation is then attempted again for sectors associated with any off-track errors that occurred during the disk access operation. In another embodiment, when an off-track error occurs during a sequential write operation in a shingled magnetic recording drive, the data originally targeted to be written to a first portion is written to a second portion of the data track that follows the first portion. Since no additional revolutions of the disk are needed for data associated with the sequential write operation to be written to the disk.

A method of assembly a dual stage actuated suspension includes either applying an adhesive to a microactuator motor and then B-staging the adhesive, or applying an adhesive that has already been B-staged such as in film adhesive form to the microactuator then assembling the microactuator into a suspension and then finishing the adhesive cure. The adhesive can be applied to bulk piezoelectric material, with the adhesive being B-staged either before or after it is applied to the bulk piezoelectric material, and the piezoelectric material then singulated into a number of individual piezoelectric microactuators. The method allows greater control over how much adhesive is used, and greater control over spread of that adhesive and control over potential contamination, than traditional liquid epoxy dispense methods.

A first time period is determined during which a first head driven by a first actuator will be performing a track-following operation. A second time period is also determined during which a second head driven by a second actuator will be performing a low-priority disk access operation that includes a seek. The first and second actuators are independently movable such that the first and second disk access operations are capable of being performed in parallel. If it is determined that the seek of the second head will impact servo control of the track-following operation of the first head, a start time of the seek of the second head is changed to correspond to a time that mitigates impacts to the track-following operation of the first head.

A data storage device is disclosed comprising a first head actuated over a first disk surface, wherein the first head comprises a write coil and a write-assist component. First data is written to the first disk surface using the write coil and the write-assist component of the first head. An electrical bias is applied to the write-assist component of the first head to physically damage the write-assist component, thereby rendering the first disk surface read-only.

Provided is a PSA sheet that has a high level of moisture resistance while maintaining good holding power with reduced gas emission. The PSA sheet provided by this invention comprises a moisture-impermeable layer and a PSA layer provided to one face of the moisture-impermeable layer. The PSA layer comprises a polymer A having a weight average molecular weight of 510.sup.4 or higher as a base polymer and a polymer B having a number average molecular weight of 1000 or higher and a weight average molecular weight lower than 510.sup.4.

A method of manufacturing a piezoelectric microactuator having a wrap-around electrode includes forming a piezoelectric element having a large central electrode on a top face, and having a wrap-around electrode that includes the bottom face, two opposing ends of the device, and two opposing end portions of the top face. The device is then cut through the middle, separating the device into two separate piezoelectric microactuators each having a wrap-around electrode.

According to one embodiment, a magnetic disk device includes a disk, a head that writes data to the disk and reads data from the disk, and a controller that obtains a gain to be changed according to a first value calculated based on first position information of the head and second position information of the head when writing a first track to the disk, calculates third position information of the head calculated based on the gain and the second position information, and writes a second track adjacent to the first track in a radial direction according to the third position information.

In a two-dimensional magnetic recording (TDMR) system, a first finite impulse response (FIR) filter processes data read from a track of a magnetic medium by a first head using first filter tap values determined a priori independently of a second head. A second FIR filter processes data read from a track by the second head using second filter tap values determined a priori independently of the first head. An off-track detector detects whether one or more of the first and second heads is off of the tracks being read. A gain controller controls gains for the first and second FIR filters based on whether one or more of the first and second heads is off of the tracks being read.