721 results about "Flying height" patented technology

A micro-actuator is comprised of a piezoelectric motor mounted on a flexure tongue with offsetting hinges, to perform a fine positioning of the magnetic read/write head. The substantial gain in the frequency response greatly improves the performance and accuracy of the track-follow control for fine positioning. The simplicity of the enhanced micro-actuator design results in a manufacturing efficiency that enables a high-volume, low-cost production. The micro-actuator is interposed between a flexure tongue and a slider to perform an active control of the fly height of the magnetic read/write head. The induced slider crown and camber are used to compensate for thermal expansion of the magnetic read/write head, which causes the slider to be displaced at an unintended fly height position relative to the surface of the magnetic recording disk. The enhanced micro-actuator design results in reduced altitude sensitivity, ABS tolerances, and reduced stiction. The controlled fly height of the magnetic read/write head prevents a possibility of a head crash, while improving the performance and data integrity.

A magnetic head includes a slider having an air bearing surface (ABS) and a trailing surface, with a transducer fabricated on the trailing surface. The transducer includes an adjunct pole disposed in a first general plane, the adjunct pole having a front edge that is recessed from the ABS and a rear edge. A main pole of the transducer is formed adjacent the adjunct pole, the main pole having a write tip that extends approximately to the ABS. A write coil having a first layer of turns is disposed in a second general plane below the adjunct pole. The magnetic head further includes a heating element, a portion of the heating element being disposed in the first general plane behind the rear edge of the adjunct pole.

A disk drive is disclosed which generates a pole tip protrusion (PTP) measurement by performing a write operation to heat the transducer while measuring a fly height of the transducer. A first data sequence written to the disk is read without heating the transducer to generate a first signal measurement. A second data sequence is then written to the disk in order to heat the transducer, and the first data sequence is again read to generate a second signal measurement. The PTP measurement is then generated in response to the first and second signal measurements.

A read/write head for use in a data storage device to control the low dynamic flying height in order to achieve high data recording storage capacity of magnetic hard drives. The read/write head is designed for use in a data storage device that includes a storage medium having a recording surface. The head comprises a pole tip region and an actuator. In turn, the actuator includes an excitation source for generating a magnetic field, and a magnetostrictive plate for expanding in response to the magnetic field, resulting in a protrusion in a section of the pole tip region along a direction towards the recording surface, so that the head flies above the recording surface at a flying height lower than a nominal flying height.

A magnetic recording device includes a slider having an air bearing surface (ABS), a leading side, and a trailing side and a head residing on the slider. The head has a first magnetic transducer and a first heater for heating an area proximal to the first magnetic transducer. A first shield (S1) comprising a first material is on the leading side of the first magnetic transducer and a second shield (S2) comprising the first material is on the trailing side of the first magnetic transducer. A first pole (P1) comprising the first material is on the trailing side of the second shield (S2), and the first pole (P1) is between 0.6 micron and 2.0 micron thick; and the second shield (S2) is less than 0.6 micron thick. A hard disk drive includes the magnetic recording device.

A disk drive to reduce head instability during disk drive manufacturing is disclosed. The disk drive comprises: a disk; a dynamic flying height (DFH) read/write head; a flying height actuator to control the spacing between the DFH read/write head and the disk; and a controller. The controller controls operations in the disk drive including applying a sloped increasing power between a first voltage and a second voltage to move the DFH read/write head towards the disk.

A head for use in a drive includes a heating element capable of generating heat sufficient to cause the head to have a shape that is similar or identical to the shape that the head has when performing an operation (e.g. writing) on a recording medium in the drive. The heating element is activated when the operation is not being performed. Hence, a head generates the same amount (or similar amount) of heat and is therefore at the same temperature (also called “operating temperature”), regardless of whether or not an operation (such as writing) is being performed. Therefore, the head maintains a fixed shape or has a shape that varies minimally, within a predetermined range around the fixed shape, that in turn results in maintaining fly height (distance between the head and the recording medium). The heating element may be implemented to use loss mechanisms inherent in a write transducer, e.g. by providing a center tap to the write transducer. When using a center tapped write transducer, currents in phase with one another are provided to perform a write operation. When not performing the write operation, the same currents are provided, but out of phase.

Disclosed is a magnetic disk that has excellent durability, particularly excellent LUL durability, and excellent alumina resistance and has a high level of reliability under a low flying height of a magnetic head involved in a recent tendency toward a rapid increase in recording density and a very severe environment resistance requirement due to diversified applications. A magnetic disk (10) comprises a substrate (1) and at least a magnetic layer (6), a carbon-based protective layer (7), and a lubricating layer (8) provided in that order over the substrate (1). The lubricating layer (8) contains a compound that has a perfluoropolyether main chain in the structure thereof and has an aromatic group and a polar group at the end of the molecule.

A method comprising receiving a pulse generated in response to a transition of a head over a predetermined pattern on a storage medium, measuring a first amplitude of a power spectrum of the pulse at a first predetermined frequency and a second amplitude of the power spectrum of the pulse at respective second predetermined frequencies, and calculating a distance between the head and the storage medium based on a function of the first and second amplitudes.

Embodiments of the invention appropriately control the flying height of a magnetic head slider as necessary without making the magnetic head slider touch the magnetic disk. In one embodiment, when a magnetic disk drive is started, the level of electric power predefined for the ordinary temperature (room temperature) is read in from the internal memory of an MPU. A temperature sensor measures the internal temperature of the magnetic disk drive and sends it to the MPU. According to the temperature sent from the temperature sensor, the MPU calculates the level of electric power which should be applied to a flying height adjustment structure. According to the calculated electric power, the MPU increases or decreases the electric power applied to the flying height adjustment structure. At a flying height controlled (corrected) by the flying height adjustment structure, a magnetic head slider performs read/write on a magnetic disk.

A HGA comprises a slider, a suspension to load the slider, a flying height controller for controlling flying height of the slider; and a flexible cable to be electrically connected with the slider and the flying height controller. In the present invention, the flying height controller comprises at least one piezoelectric piece disposed between the slider and the suspension. The HGA further comprises ACF to connect the flying height controller with the suspension and the flexible cable. The invention also discloses a disk drive unit with the HGA, a method for flying height control with the HGA, and a system for controlling flying height.

Methods, circuits, and systems for processing a preamble field in a read channel (e.g., in a magnetic storage device such as a hard disk drive). The methods generally include the steps of (a) reading the preamble field, wherein the preamble field comprises a repetitive bit pattern having a logical transition every x bit periods, where x is an integer of at least 3 when d is 0 or 1, or where x is an integer of at least d+2 when d is greater than 1, and (b) processing the repetitive bit pattern. The methods may further relate to processing the preamble for synchronization with the read channel and/or for measuring the fly height of a read/write head. The invention also relates to methods of enabling read channel synchronization and/or fly height measurement. The circuitry for fly height measurement generally includes (a) reading logic configured to read a preamble field from a read channel, wherein the preamble field comprises a repetitive bit pattern, (b) determination logic configured to determine a characteristic of the repetitive bit pattern, and (c) correlation logic configured to correlate the characteristic to the fly height. The systems generally comprise those that include a circuit embodying one or more of the inventive concepts disclosed herein. The present invention advantageously provides improved resolution of signals resulting from the preamble fields and of harmonics of said signals, and enables fly height measurement and improved channel synchronization without consuming dedicated tracks, platters, etc. on a magnetic recording medium.

Embodiments of the invention improve the power consumption and response speed of a heater for the gap flying height (hg) adjustment, to minimize an influence that the heater has on a life of a read element, and to provide a heater having resistance lines reduced in breaking and ensuring higher reliability. In one embodiment, a read/write element is formed near an air bearing surface (ABS) on a slider, and the circumference of the read/write element is filled with alumina. The read/write element includes an upper magnetic pole piece, a lower magnetic pole piece, a coil, and a resist filling around the coil, and a read element (MR) for performing reading, and an upper shield and lower shield for protecting the read element from an external magnetic field. A heater for adjusting the flying height is provided between the slider and the read/write element but near the read/write element. A temperature gradient relaxing material having a thermal conductivity higher than that of the heater and that of a material (alumina) filling around the heater is formed near the heater.

The invention discloses equipment and a method for proportionally remote controlling a vehicle and an unmanned aerial vehicle by touching on intelligent terminal. The method comprises the following steps of setting a direction speed control area, a speed gear adjusting area, a flying height control area and a mode selection key area on a touch screen of the intelligent terminal, wherein the key area comprises remote control selection keys of different equipment; meanwhile, setting a state display area on a display unit; detecting a touch gesture on the touch screen; making sure that the detected gesture is a slide gesture in a direction control touch area; according to the slide track, calculating the slide direction and the slide distance of the gesture; transmitting control information containing flying direction and speed to the remote controlled equipment. Compared with the prior art, the equipment and the method have the advantages that operation action on the equipment, such as remote control vehicle and the unmanned aerial vehicle, on the intelligent terminal is simplified, and the using experience of controlling the equipment through the intelligent terminal by a user can be greatly improved.

A thermal flying height adjustment slider capable of being mounted on a small-sized thin film magnetic head slider is provided wherein terminals of an energizer serving as a heater prevent corrosion of pole pieces and the number of terminals is reduced. In one embodiment, one of terminals of the energizer serving as the heater is electrically connected to the lower pole piece, so that a relay terminal for a heating device is used also as the terminal for preventing the corrosion of pole pieces.

A fly height controller (10FHC; 10FHC′) for controlling the fly height of a read/write head assembly (15) in a disk drive (20) is disclosed. A heat element resistor (30) is disposed within the read/write head assembly (15). The fly height controller (10FHC; 10FHC′) includes registers (32R, 32W) for storing digital data words corresponding to the desired drive levels to be applied to the heat element resistor (30) during read and write operations. The registers (32R, 32W) are selectively coupled to a steady-state digital-to-analog converter (DAC) (36), depending upon whether a read or write operation is occurring; the output of the steady-state DAC (36) is applied to a voltage driver (40), which in turn drives current into the heat element resistor (30). Overdrive and underdrive transistors (44P, 44N) are provided to overdrive and underdrive the input to the voltage driver (40) in transitions between read and write operations. An initial state register (50) receives a digital word indicating the desired current for the heat element resistor (30) when unselected; the output of the initial state register (50) is applied to an initial state DAC (52), which drives an initial state voltage driver (54). Control logic (35; 35′) controls whether the steady-state voltage driver (40) or initial state voltage driver (54) drives the heat element resistor (30). The fly height controller (10FHC′) may also be adapted to control the fly height of multiple read/write head assemblies (15) in a disk drive.

A system and method for determining head-disk contact (HDC) in a magnetic recording disk drive uses the signal from the magnetoresistive (MR) read head. The analog MR signal is digitized and input to a digital signal processor with circuitry and/or software for integrating the signal amplitude over a low-frequency range. The calculated value from the integration when the slider is out-of-contact with the disk is a reference value. The same integration is then performed during operation of the disk drive and the measured value is compared to the reference value. If the measured value exceeds the reference value by some predetermined amount, this is an indication of the onset of HDC or that HDC has occurred. The method can be used in head-disk testers to facilitate the design and testing of disk drive components, such as slider-suspension assemblies and fly-height actuators located on the slider to alter the head-disk spacing, and in disk drives to control fly-height actuators and to take corrective action prior to HDC.

A method and a device for airborne laser scanning flying height change real-time compensation can eliminate adverse effect of flying height change to a laser scanning point cloud distribution area and cloud density of a laser scanning point. When the flying height of an airborne platform is changed, a flying height change value is acquired by a global position system(GPS)/ inertial navigation system(INS)integrated measurement device, the value of a scan field angle which can keep the width of a scanning stripe unchanged and the value of a laser pulse frequency which can keep the laser scanning point cloud density unchanged are calculated in a flying height compensation controller. A rotating prism photoelectric shaft angle encoder measures and obtains a real time rotating angle of a rotating prism and offers the real time rotating angle of the rotating prism to the flying height compensation controller, a square signal which is identical with an expect laser pulse frequency value is outputted only within a scope of the required scan field angle and offered to a laser pulse transmitter, thus a laser transmitter can launch a laser pulse of the corresponding frequency. By using the compensation method, the flying height change of the airborne platform can not affect the laser scanning point cloud distribution area and cloud density of a laser scanning point permanently.

An embodiment of the invention is a slider with a lift pad and a thermal protrusion pad in which the heads are located. The lift pad is located immediately in front of the thermal protrusion pad and is designed to achieve the flying characteristics needed for normal operation of the disk drive. The thermal protrusion pad includes a heater which is used to protrude the pad for burnishing-on-demand and/or for thermal fly-height control. The thermal protrusion pad is designed to generate very little lift so that protruding the thermal protrusion pad does not significantly increase the lift expericence by the slider. An alternative embodiment uses two overcoat thicknesses on the ABS surface with the thermal protrusion pad having a thin overcoat and the lift pad having a thicker overcoat.