Abstract: A method is provided for controlling movement of a tape in a data storage and retrieval system having a tape roller servo subsystem for controlling movement of a tape, and a head servo subsystem for controlling position of a head element mounted on a rotatable carriage unit. The method includes receiving, from the head servo subsystem, a head element position feedback signal at the tape roller servo subsystem; and controlling movement of the tape by the tape roller servo subsystem based, at least in part, on the head element position feedback signal.

Abstract: In one embodiment, a tape movement constraint comprises a tiltable tape roller bearing having a grooved surface adapted to contact and engage a surface of the tape as the roller barrel rotates. An actuator adapted to pivot the roller bearing surface controls the lateral position of a tape. In operation, in one embodiment, the roller barrel of the roller bearing is rotated by engaging a surface of the tape roller barrel with a longitudinally moving magnetic tape. At least a portion of any air bearing between the moving tape and the barrel surface is quenched using grooves formed in the barrel surface. The lateral position of the moving tape is sensed and the rotating roller barrel is tilted in response to the sensed lateral position of the moving tape to control the lateral position of the moving tape. Other embodiments are described and claimed.

Abstract: A method and apparatus for transferring data. First data is transferred in a first direction on a surface of a selected magnetic disk in a plurality of magnetic disks using a first actuator assembly. Second data is transferred in a second direction on the surface of the selected magnetic disk in the plurality of magnetic disks using a second actuator assembly, while the first data is being transferred in the first direction by the first actuator assembly.

Abstract: A magnetic disk device includes: a recording medium provided with a plurality of write tracks; a magnetic write head including a magnetic pole, side shields, and a leading shield, a distance from the magnetic pole to each of the side shields being maintained to be uniform with a gap layer therebetween, and a distance from the magnetic pole to the leading shield being maintained to be uniform with a gap layer therebetween; and a control section rotating the recording medium, and allowing magnetic information to be recorded on the recording medium while allowing the magnetic write head to travel in a direction from an inner write track toward an outer write track or in a direction from the outer write track toward the inner write track, across write tracks in the recording medium. With such a configuration, format efficiency may be improved, and a width of an erase band on a magnetic disk may be minimized.

Abstract: A method of operation of a servo writing system includes: initializing a disk and a head positioned over the disk for writing a servo pattern on the disk; calculating a target velocity profile for writing the servo pattern on the disk; setting a movement profile for operating the disk, the head, or a combination thereof to the target velocity profile; determining a back electromotive force from operating the disk, the head, or a combination thereof according to the movement profile; calculating an actual profile of the movement of the disk, the head, or a combination thereof from the back electromotive force; and adjusting the movement profile by the actual profile to match the actual profile to the target velocity profile for writing the servo pattern on the disk.

Abstract: A magnetic disk is provided which is excellent in durability of the magnetic disk or particularly in LUL durability and CFT characteristics and has high reliability under a decreased floating amount of the magnetic head accompanying the recent rapid increase in a recording density and extremely severe environmental resistance accompanying diversification of the applications. The magnetic disk of the present invention is a magnetic disk having at least a magnetic layer, a carbon protective layer, and a lubrication layer sequentially provided on a substrate, and the lubrication layer is a film formed by a lubricant that contains two types of compounds having a perfluoropolyether main chain in the structure, a molecular weight distribution of the two types in total being within a range of 1 to 1.

Abstract: A magnetic disk device performs test write before storing system information to check the state of each head. The magnetic disk device then stores test write results in a test-write-result table of a RAM. The magnetic disk device then determines whether the number of defective heads is equal to or greater than a predetermined number. When the number of defective heads is equal to or greater than the predetermined number, the magnetic disk device suspends the process of storing the system information. When the number of defective heads is less than the predetermined number, the magnetic disk device refers to the test write results stored in the test-write-result table and performs write only with a head determined as normal.