Abstract: A method for determining the surface distortions of a disk in a spin-stand or single or multiple disk hard disk drive (HDD) utilizing a DFH type write head. A stepwise power curve is supplied to the DFH head, the head is flown over a chosen track on the disk, and the high frequency signal from a HDI sensor is analyzed in order to determine the step of an initial touchdown power and the step of a complete touchdown power as a function of individual sectors in a sector subdivision along a chosen track. The HDI sensor signal is averaged within each step of the power curve between these two steps and a Ratio variable, Ratio=(Max. amplitude)/(RMS amplitude) is calculated for each step and is averaged over each rotation of the disk during the step.

Abstract: Measuring method of a magnetic head includes (a) placing the magnetic head at normal position, defining a first direction parallel to an air bearing surface and two shielding layers of the magnetic head, and defining a second direction perpendicular to the first direction; (b) tilting the magnetic head at an angle to the second direction, applying a plurality of first magnetic fields with different intensities in the first direction, and measuring out a first output parameter curve; (c) repeating the step (b) with different angles and measuring out a plurality of first output parameter curves; (d) calculating a plurality of pinned direction tilt ratios that a pinned direction of a pinned layer of the magnetic head tilts towards the second direction according to the parameter curves; and (e) calculating a pinned direction tilt angle that the pinned direction tilts towards the second direction according to the pinned direction tilting ratios.

Abstract: There is disclosed a test apparatus for performing testing with a read/write head and method of testing with a test apparatus. The test apparatus includes a head load mechanism for receiving and positioning the read/write head during testing and a multi-channel preamplifier arranged to interface plural channels to a measurement system. A first channel of the multi-channel preamplifier has a connector for connecting to the read/write head. One or more other channels of the multi-channel preamplifier is connected to or has a connector for connecting to another device for interfacing that device to the measurement system.

Abstract: A structure for preventing Electrostatic Discharge (ESD) damage to a magnetoresistive sensor during manufacture. The structure includes a switching element that can be switched off during testing of the sensor and then switched back on to provide ESD shunting to the sensor. The switch can be a thermally activated mechanical relay built onto the slider. The switch could also be a programmable resistor that includes a solid electrolyte sandwiched between first and second electrodes. One of the electrodes functions as an anode. When voltage is applied in a first direction an ion bridge forms across through the electrolyte across electrodes making the resistor conductive. When a voltage is applied in a second direction, the ion bridge recedes and the programmable resistor becomes essentially non-conductive.

Abstract: There is disclosed a spinstand for testing a head gimbal assembly. The spinstand includes a gripper operable to grip the head gimbal assembly and a load pick device operable to hold a head gimbal assembly and to move the head gimbal assembly into an exchange position where it can be gripped by the gripper. In the exchange position part of the load pick device registers with the gripper and another part of the load pick device is spaced from the gripper so as to form a space between, in which space at least part of the head gimbal assembly is located in use.

Abstract: A method and apparatus for scanning a read/write head of a hard disk drive during manufacture are presented. The method includes: providing a magnetic sensor; moving the magnetic sensor relative to and in close proximity to the read/write head under test; obtaining measurements from the head under test or the sensor, representing a two-dimensional magnetic map; processing the map to obtain an accurate map of the head sensitivity of the head under test from which the key performance characteristics of the head can be obtained.

Abstract: A temperature sensor of a head transducer measures temperature near or at the close point. The measured temperature varies in response to changes in spacing between the head transducer and a magnetic recording medium. A detector is coupled to the temperature sensor and is configured to detect a change in a DC component of the measured temperature indicative of onset of contact between the head transducer and the medium. Another head transducer configuration includes a sensor having a sensing element with a high temperature coefficient of resistance to interact with asperities of the medium. Electrically conductive leads are connected to the sensing element and have a low temperature coefficient of resistance relative to that of the sensing element, such thermally induced resistance changes in the leads have a negligible effect on a response of the sensing element to contact with the asperities.

Abstract: A head transducer, configured to interact with a magnetic recording medium, includes a first sensor having a temperature coefficient of resistance (TCR) and configured to produce a first sensor signal, and a second sensor having a TCR and configured to produce a second sensor signal. One of the first and second sensors is situated at or near a close point of the head transducer in relation to the magnetic recording medium, and the other of the first and second sensors spaced away from the close point. Circuitry is configured to combine the first and second sensor signals and produce a combined sensor signal indicative of one or both of a change in head-medium spacing and head-medium contact. Each of the sensors may have a TCR with the same sign (positive or negative) or each sensor may have a TCR with a different sign.

Abstract: A property, such as a quality parameter, of a write pole in a write head is determined using an optical metrology device, where the write pole is smaller than the optical resolution limit of the metrology device. The metrology device produces polarized light that is reflected off the write pole while the write pole is magnetized either during or after excitation with a write current. The magnetization alters the polarization state of the light, which can be analyzed to transform the altered polarization state into intensity. The intensity of the light is detected over the point spread function of the optics in the metrology device and an intensity value is generated. The intensity value is used to determine the quality parameter of the write pole, e.g., by comparison to a threshold or reference intensity value, which may be generated empirically or theoretically.

Abstract: A data storage library is described including a plurality of tape cartridges wherein each of the tape cartridges possesses an auxiliary radio frequency memory device in which auxiliary digital data is stored. The library also includes at least one drive disposed substantially within the library capable of transferring user data to and from one of the tapes. The library further includes at least one auxiliary radio frequency memory device reader that capable of reading the auxiliary digital data and transmitting the auxiliary digital data to at least one designated location, the reader is independent of the at least one drive.

Abstract: A method and apparatus to control a flying height of a head in a disk drive by detecting a flying state of the head just before it touches down to a disk. The method includes detecting approximate touch-down based on detecting a motion change of a head in a disk track direction by changing a flying height of the head on a rotating disk and determining that the head approaches a touch-down approximated flying height when the detected motion change of the head in the disk track direction exceeds a threshold value.

Abstract: In the brushless motor, a hub has a cylindrical separating wall in between a yoke and two magnetic recording disks. The yoke is affixed to the inner surface of the separating wall of the hub using both a press-fit and adhesion. A first convex portion and a second convex portion are formed on the inner surface of the separating wall, and the yoke is pressed against these convex portions in the case where the yoke is press-fit. The first convex portion and the second convex portion are formed in a ring shape around the rotational axis of the motor. The diameter of the first convex portion is less than the diameter of the second convex portion.

Abstract: A disk drive suspension is provided with a load beam and a flexure including a tongue portion on which a slider is mounted. A pair of bent edge portions are formed by bending regions which extend along opposite side edges of the load beam in a thickness direction. A pair of limiters are formed on those parts of the load beam where the bent edge portions are provided. The limiters each include an arm portion and a retainer portion. An aperture for defining a contour of each limiter is formed in a region which extends along each side edge of the load beam. Each limiter is bent in a direction opposite to that of each corresponding bent edge portion.