Abstract: A hard disk drive having a self servo write offset error correction mechanism to improve self servo write process is disclosed. In accordance with certain aspects of the present invention, there is provided a self servo write method that can measure an accurate position offset between the read-head element and write-head element incorporated in a disk drive before servo data is recorded on the disk provided in the disk drive.

Abstract: A hard disk drive having a self servo write offset error correction mechanism to improve self servo write process is disclosed. In accordance with certain aspects of the present invention, there is provided a self servo write method that can measure an accurate position offset between the read-head element and write-head element incorporated in a disk drive before servo data is recorded on the disk provided in the disk drive.

Abstract: Apparatuses and/or systems for performing self-servo write using a helium environment are provided. In one embodiment, an intake tube is coupled to an intake hole that is associated with an enclosure for enclosing a recording disk. A helium gas transport mechanism is coupled to the intake tube and the helium gas transport mechanism causes substantially helium gas to be transported to the enclosure.

Abstract: A method for preventing data loss in a hard disk drive by projecting reduction in gas concentration using insitu non-repeatable runout is disclosed. The method includes using servo tracking error to obtain a measured value of insitu non-repeatable runout (NRRO) for the hard disk drive, the hard disk drive having been filled with the gas and hermetically sealed. The measured value of NRRO is then deconvolved into a plurality of values for flow induced NRRO components. These values of NRRO and of flow induced NRRO components are compared to predetermined limiting values and a time when one of the predetermined limiting values will be reached is predicted. Action is then applied as appropriate.

Abstract: A method for preventing data loss in a hard disk drive by projecting reduction in gas concentration using insitu non-repeatable runout is disclosed. The method includes using servo tracking error to obtain a measured value of insitu non-repeatable runout (NRRO) for the hard disk drive, the hard disk drive having been filled with the gas and hermetically sealed. The measured value of NRRO is then deconvolved into a plurality of values for flow induced NRRO components. These values of NRRO and of flow induced NRRO components are compared to predetermined limiting values and a time when one of the predetermined limiting values will be reached is predicted. Action is then applied as appropriate.

Abstract: A method is presented for reducing time loss during manufacture and testing of a hard disk drive by predicting reduction in gas fill. The method includes using servo tracking error to obtain a measured value of insitu non-repeatable runout (NRRO) for the hard disk drive, the hard disk drive having been filled with the gas and semi-sealed. The measured value of NRRO is then deconvolved into a plurality of values for flow induced NRRO components. These values of NRRO and of flow induced NRRO components are compared to predetermined limiting values and a time when one of the predetermined limiting values will be reached is predicted. Action is then applied as appropriate.

Abstract: Methods of performing self-servo write using a helium environment are provided. In one embodiment, a recording disk is placed in an enclosure. The enclosure is filled with a gas that is substantially helium. Self-servo write is used to write circular track positioning information on the recording disk.

Abstract: Methods of performing self-servo write using a helium environment are provided. In one embodiment, a recording disk is placed in an enclosure. The enclosure is filled with a gas that is substantially helium. Self-servo write is used to write circular track positioning information on the recording disk.

Abstract: Apparatuses and/or systems for performing self-servo write using a helium environment are provided. In one embodiment, an intake tube is coupled to an intake hole that is associated with an enclosure for enclosing a recording disk. A helium gas transport mechanism is coupled to the intake tube and the helium gas transport mechanism causes substantially helium gas to be transported to the enclosure.

Abstract: A disk drive manufacturing method calibrates the stitching gain of a position error signal (PES) by sampling servo information from a quadrature servo pattern while the head is maintained at the quarter-track positions and then calculating the kurtosis of the distribution of the PES values calculated from the samples. Because the kurtosis is a measure of the deviation from a normal or Gaussian distribution, the kurtosis of a PES distribution is used to optimize the stitching gain value through iteration until the kurtosis is close to zero, indicating that the PES with the optimal stitching gain values has a near-Gaussian distribution. The stitching gain calibration is performed for all heads and for multiple tracks across the surface of the disk for each head. The resulting values of stitching gain, each associated with a head and track, are stored in the disk drive memory and recalled during operation of the disk drive.

Abstract: A disk storage system having servo data stored thereon for accurate head position control over a magnetic or other storage medium. The servo data is seamless and untrimmed and consists of a primary servo burst set (AB burst) in which the difference defines the desired tract pitch for the surface. Multiple secondary servo burst sets (e.g., CD burst and EF burst) are written at the desired track pitch but radially offset from the primary burst set. In one embodiment, two secondary servo burst sets are used, but alternatively, any number of secondary servo burst sets could be used. In this exemplary embodiment having two secondary servo burst sets, the CD servo burst set is offset by ? of the track pitch from the primary servo burst set. Also in this embodiment, the EF servo burst set is offset by ? of the track pitch from the primary servo burst set. There are six bursts per set. The servo data is written in multiple servo sectors around the surface of the medium.