Abstract: Systems and methods for improving loading and unloading of a read or write head onto and off of a disk medium. Particular embodiments may assist in loading a read or write head to, or unloading a read or write head from, a load location over a surface of a disk medium in such a manner that damage to the surface of the disk medium (e.g., load location) is either prevented or minimized. The prevention or reduction of damage may be achieved by ensuring that a read or write head has sufficient clearance over the surface of a disk medium as the read or write head moves over the surface (e.g., as the head moves parallel to the surface) during a head loading or unloading process.

Abstract: Systems and methods for improving loading and unloading of a read or write head onto and off of a disk medium. Particular embodiments may assist in loading a read or write head to, or unloading a read or write head from, a load location over a surface of a disk medium in such a manner that damage to the surface of the disk medium (e.g., load location) is either prevented or minimized. The prevention or reduction of damage may be achieved by ensuring that a read or write head has sufficient clearance over the surface of a disk medium as the read or write head moves over the surface (e.g., as the head moves parallel to the surface) during a head loading or unloading process.

Abstract: A method monitors operation of a disk drive. The method includes providing a disk drive which includes a rotating disk and a head having a read transducer in proximity to a surface of the disk and an adjustment mechanism which controllably adjusts an average relative spacing between the read transducer and the surface. The method further includes generating a read-back signal by reading from the surface using the read transducer. The read-back signal includes a high frequency carrier signal having an envelope that is modulated by a lower frequency signal. The method further includes varying the average relative spacing between the read transducer and the surface using the adjustment mechanism. The method further includes analyzing the envelope in the frequency domain and detecting an emergence of at least one frequency component of the envelope within an air bearing resonance range of frequencies.

Abstract: Head stack fixtures for securing head stack assemblies to spin stand testing systems, and spin stand testing systems incorporating such fixtures, are disclosed. Exemplary head stack fixtures comprise a base supporting a piezoelectric actuator. The base includes an attachment mechanism for securing the HSA in such a way that the HSA will pivot relative to the base. When the HSA is secured to the base, the piezoelectric actuator engages the HSA. The piezoelectric actuator is therefore able to pivot the HSA relative to the base for fine positioning of a head of the HSA.

Abstract: A spin stand testing system is used to determine a positioning range of a microactuator disposed on a head gimbal assembly. The microactuator is configured to laterally translate a read sensor of a head of the head gimbal assembly through the positioning range. The spin stand testing system includes a disk having a track, and a secondary mover configured to laterally translate the head gimbal assembly. During testing, a feedback loop keeps the read sensor locked to the track. While the read sensor remains locked, the head gimbal assembly is translated laterally. The microactuator translates the read sensor in an opposite direction until the microactuator reaches an end of its range, which is determined by monitoring a signal. The amount of translation of the head gimbal assembly by the secondary mover when the signal indicates the end of the range is the measured positioning range in one direction.

Abstract: Methods of measuring position error due to pole tip protrusion are provided. In exemplary embodiments, a head having a write element is aligned to a track, and then pole tip protrusion is induced in the write element by writing to the track. The position error is measured after the pole tip protrusion has been induced. The position error can be measured just after the write element stops writing so that the position error is measured before the position error degrades or relaxes. Alignment of the head to the track, and measurement of the position error are accomplished while the head is over a servo segment of the track. The servo segment can be provided with separate alignment and evaluation portions for aligning the head and for measuring the position error, respectively. The alignment and evaluation portions can each encode two parallel sub-tracks, each with a different frequency.

Abstract: An apparatus for testing magnetic heads that interact with magnetic disks includes a translational slide and a rotatable arm mounted to one end of the slide. The translational slide moves the rotatable arm in a longitudinal direction parallel to the surface of a magnetic disk. The arm rotates the magnetic head to different positions relative to data tracks on the disk. A second translational slide moves the magnetic head vertically above the disk to adjust the vertical position of the head. The three movements of the head, (1)horizontally across the disk, (2)rotationally by the arm, and (3)vertically relative to the disk surface are controlled by servomechanisms. A read/write amplifier circuit is connected to the head under test. The test apparatus is controlled by a computer that interfaces with circuitry connected to the servomechanisms.

Abstract: An apparatus for testing magnetic heads that interact with magnetic disks includes a translational slide and a rotatable arm mounted to one end of the slide. The translational slide moves the rotatable arm in a longitudinal direction parallel to the surface of a magnetic disk. The arm rotates the magnetic head to different positions relative to data tracks on the disk. A second translational slide moves the magnetic head vertically above the disk to adjust the vertical position of the head. The three movements of the head, (1)horizontally across the disk, (2)rotationally by the arm, and (3)vertically relative to the disk surface are controlled by servomechanisms. A read/write amplifier circuit is connected to the head under test. The test apparatus is controlled by a computer that interfaces with circuitry connected to the servomechanisms.

Abstract: A testing apparatus for detecting popcorn noise in magnetic heads comprises a fully integrated testing system which includes an analog circuit portion and a digital circuit portion. The analog circuit portion is implemented to interface with a magnetic head while the digital circuit portion is designed to store the testing sequence, analyze the testing data, control and execute the testing routines. The testing apparatus is designed for production environments where testing data are required instantaneously as feedback for production process monitoring.

Abstract: A system for testing a voice coil member of a rotary actuator head stack assembly (HSA) of a disk drive includes a plurality of testing circuits, each of which selectively performs at least one predefined test on the voice coil member. During testing, the head stack assembly is removably mounted on a base plate with the axis of rotation of the head stack assembly normal to the top surface of said base plate. A flat reference coil is disposed in a fixed position parallel to the top surface of the base plate to provide an inductively coupled relationship between the reference coil and the coil under test. The ends of the coil under test are connected to a pair of terminals in the base plate. A polarity test circuit for determining the polarity of the coil under test is connected to the terminals. Other test circuits are selectively connected to the terminals and the tests are conducted in a controlled sequence without the need to move the fragile head stack assembly.