Abstract: Performing embedded runout correction for a track on a rotational data storage disk includes measuring written-in runout for the track, selecting a number of revolutions in response to the measured written-in runout of the track, calculating embedded correction values for the track for the selected number of revolutions of the rotational data storage disk, and storing the embedded correction values.

Abstract: A disk drive measures the radial misposition of tracks and repositions the tracks at regularly spaced intervals. Written in runout (WRO) in servo bursts is determined to calculate track spacing and squeeze among adjacent tracks. Tracks with improper spacing are repositioned by adding a squeeze correction term to the servo wedges. Thereafter, when the disk drive operates to store data, the servo bursts are used to calculate a position error signal (PES), and the squeeze correction term is combined with the PES to position the head at a proper track radius.

Abstract: Performing embedded runout correction for a track on a rotational data storage disk includes measuring written-in runout for the track, selecting a number of revolutions in response to the measured written-in runout of the track, calculating embedded correction values for the track for the selected number of revolutions of the rotational data storage disk, and storing the embedded correction values.

Abstract: A method and apparatus for providing a temporary utility zone in a disk drive. A disk surface has a write head associated therewith. The write head is used to write spiral servo information and a propagation state indicator onto the disk surface. The spiral servo information and propagation state indicator are used to perform a self-servo write operation on the disk surface.

Abstract: A disk drive measures the radial misposition of tracks and repositions the tracks at regularly spaced intervals. Written in runout (WRO) in servo bursts is determined to calculate track spacing and squeeze among adjacent tracks. Tracks with improper spacing are repositioned by adding a squeeze correction term to the servo wedges. Thereafter, when the disk drive operates to store data, the servo bursts are used to calculate a position error signal (PES), and the squeeze correction term is combined with the PES to position the head at a proper track radius.

Abstract: A method and apparatus for writing servo information to disks within a disk drive is disclosed. A servo track writer is used to write first servo information to the disks. The disk drive is then sealed, and the read/write heads within the disk drive are used to fill in second servo information. The first servo information includes digital information and A, B, C, and D servo bursts for a first number of tracks on the disks. The first servo information also includes digital information and A and B servo bursts for the remaining tracks on the disks. After the disk drive is sealed in the manufacturing process, the read/write heads within the disk drive fill in the second servo information, which includes C and D servo bursts for the remaining tracks. The read head reads the first servo information in the first number of tracks, and the position of the write head is adjusted based on the first servo information.

Abstract: The head positioner for a Winchester type hard disk drive digital storage system includes a main rotating metal body portion having outwardly extending, integral, head positioning arms. The magnetic heads for reading and writing information on the hard disks are mounted on springy members which are referred to as "load beams". In order to reduce vibration, and to increase the accuracy of positioning of the heads on the disks, the outwardly extending arms from the main metallic body of the head positioner unit extend outwardly from the central axis of rotation for a distance which is substantially greater than the additional outward extent of the spring load beams upon which the magnetic heads are supported. Preferably the outward extent of the rigid arms is in the order of twice the length of the springy load beams. In addition, the bearings for supporting the rotating head positioning assembly are preferably mounted directly to the metallic body of the head positioner assembly.

Abstract: A Winchester disk drive assembly includes upper and lower mounting plates and shafts for the main drive motor assembly and for the head positioner firmly connected to both mounting plates. One end of the shafts is mounted to one of the mounting plates by a shouldered washer. A shouldered washer is mounted in a counterbored hole in the adjacent mounting plate and is firmly secured to the adjacent shaft end by a steel screw, with the dimensions of the washer being selected to provide space between the enlarged head portion of the washer, and the counterbore, so that the shaft is entirely stress-free. The space between the inner surface of the enlarged portion of the T-shaped washer and the counterbored recess is then filled with epoxy which bonds the two parts together. The shouldered washer then becomes an essential part of the adjacent mounting plate, and the mounting plate may be removed and separated from the shaft by removing the steel screw.

Abstract: A digital memory system of the hard or Winchester disk type, includes a series of hard disks, and pivoted mounting arms for the magnetic heads or sliders. In order to minimize the vertical, or inter-disk space occupied by the sliders and their mounting arms when used in a rotary type of head positioner, the end of a direct, or straight, mounting arm for each slider is generally ring-shaped, or of an open rectangular configuration, with the outer transverse portion of the mounting arm extending through a slot in the surface of the slider which is not intended for engagement with or proximity to the recording disk. In addition, the slider is secured to the mounting arm by a small springy resilient sheet metal member, having a broad central area with a rounded protrusion intended to engage the outer transverse portion of the ring-shaped end of the mounting arm, and being bonded to the slider at the bottom of the slot in the slider on either side of the rounded bearing member.

Abstract: The head positioner for a Winchester type hard disk drive digital storage system includes a main rotating metal body portion having outwardly extending, integral, head positioning arms. The magnetic heads for reading and writing information on the hard disks are mounted on springly members which are referred to as "load beams". In order to reduce vibration, and to increase the accuracy of positioning of the heads on the disks, the outwardly extending arms from the main metallic body of the head positioner unit extend outwardly from the central axis of rotation for a distance which is substantially greater than the additional outward extent of the springy load beams upon which the magnetic heads are supported. Preferably the outward extent of the rigid arms is in the order of twice the length of the springy load beams. In addition, the bearings for supporting the rotating head positioning assembly are preferably mounted directly to the metallic body of the head positioner assembly.

Abstract: A digital storage system of the Winchester or hard disk drive type has a magnetic head positioner within which the arm-positioning body, including the heads, is rotatably mounted about a fixed stator assembly which includes a two-part shaft assembly comprising an aluminum cylindrical sleeve thermally shrink fitted about the central portion of an aluminum shaft having a pair of fixed ends and end portions reduced in diameter relative to the central portion by means of a pair of steel bearing assemblies attaching circumferentially about the sleeve in regions exclusive of the shrink fitted central portion of the shaft assembly. The clearance thus provided between the shaft and the mounting sleeve in the regions of the bearing assembly attachment permits a degree of decoupling of mechanical resonances potentially introduced into the head position servocontrol loop by mounting stresses acting upon the shaft.