204 results about "Spinning disk" patented technology

A disk drive is disclosed comprising a spindle motor for rotating a disk, wherein the current applied to the spindle motor is controlled by adjusting a duty cycle of a pulse width modulated (PWM) signal. A current sensor generates a current sense signal representing a current flowing from a supply voltage. The current sense signal is integrated to generate an integration signal. The integration signal is compared to a threshold, and the result of the comparison is used to adjust the duty cycle of the PWM signal. In this manner the disk drive draws essentially constant average input current from the supply voltage which decreases the spin up time of the disk.

A disk drive is disclosed comprising a spindle motor comprising a plurality of windings for rotating a disk. The spindle motor is rotated by commutating the windings over a plurality of commutation states, wherein audible noise generated by the disk drive is reduced by phase modulating the commutation interval. Further audible noise reduction is achieved by modulating a current applied to the windings which substantially reduces discontinuities in the torque output of the spindle motor caused by phase modulation of the commutation intervals.

A disk drive is disclosed comprising a disk, a head actuated over the disk, and a spindle motor for rotating the disk, the spindle motor comprising a plurality of windings. Disk control circuitry executes a spin-down operation of the spindle motor by estimating an angular position of the spindle motor by applying a voltage to at least one of the windings and evaluating a rise time of current flowing through the winding. The windings are commutated in response to the estimated angular position, and a driving current is applied to the windings to brake the spindle motor.

A method is disclosed for defining tracks on a rotating magnetic disk medium of a disk drive. Reference tracks are followed using a servo control loop while writing servo burst patterns defining a first target servo track. The servo control loop includes a two-dimensional digital state compensator having a first input that receives position error signals, a first output that generates control signals for positioning a transducer head, a second output that generates track-following state variables, and a second input that receives processed and stored track-following state variables. The first target track is followed using the servo control loop while servo burst patterns are written, and while the processed and stored track-following state variables corresponding to the servo burst patterns defining the first target track are applied to the second input.

A disk drive including a disk drive base and a cover attached to the disk drive base. The disk drive further includes a rotatable disk including a disk surface extending to an outer periphery. The disk drive further includes a spindle motor including an axis of rotation. The spindle motor is rotatably coupled to the disk drive base for rotating the disk about the axis of rotation. The disk drive further includes a shroud surface concentrically formed about and adjacent the outer periphery. The disk drive further includes a cavity formed in the shroud surface. The cavity extends to a cavity opening adjacent the outer periphery. The disk drive further includes an airflow diverter element extending from the cover towards the disk surface radially between the cavity opening and the axis of rotation for diverting disk rotation induced airflow adjacent the disk surface.

A system provided for protecting a disk drive from impact damages. More specifically, a disk drive is provided that includes an accelerometer interconnected to a printed circuit board that detects free fall of the disk drive. In addition, the velocity of spinning disks of the disk drive is also monitored to assess changes in velocity thereof that may indicate the presence of a tumbling condition. Furthermore, the change in acceleration measured by the accelerometer is monitored to prevent false indications of free fall due to common vibrations. Thus an enhanced system is provided that protects disk drives from the effect of free falls under a wide variety of conditions and allowing for drops from shorter distances to be identified.

An evaluation method that can easily evaluate properties of a carbon protective film and a lubricant on a magnetic-disk surface or particularly, an evaluation method of a magnetic disk in which the properties of the magnetic-disk surface can be evaluated accurately so that a strict demand for interactions between the magnetic-disk surface and a head can be met is provided. In a state in which an element portion of the magnetic head provided with the head element portion that projects by thermal expansion is projected, after being brought into contact with a predetermined radial position on the surface of the rotating magnetic disk, the head is further made to perform seeking in a state in which the element portion is projected by a specified amount, whereby the properties of the carbon film or the lubricant formed on the magnetic-disk surface is evaluated.

The invention discloses a self-adaptive control mechanism which couples an electromagnetic repulsion system with a permanent magnetism system. The invention adopts an electromagnetic repulsion device spinning disk of circular table structure, relatively to the circular disk spinning disk, which maintains the mechanical strength and output capacity of the spinning disk, simultaneously greatly reduces the increase of kinematic scheme mass of the control mechanism, and greatly enhances the driving load capacity of the control mechanism. The control mechanism of the invention adopts the self-adaptive motion proposal, which avoids the frequent high speed motion of a breaker, reduces the mechanical strength request for the breaker, and prolongs the motion life of the breaker effectively.

A RAID device is provided with a pair of non-volatile solid state data storage devices and one or more rotating disk drives, giving improved access time performance to the array. Data is staged on the pair of solid state data storage devices, and periodically backed up to the rotating disk drive(s).

A method, and system for employing the method, for virtual data storage migration providing a plurality of data storage devices communicating with at least one computer system. A plurality of data being managed by the computer system and an archive data storage device is selected from the plurality of data storage devices. Specified data is selected for archiving in the archive data storage device when the archive data meets a specified archive criteria. After the archived specified data is accessed in the archive data storage device at a predetermined frequency, the archive data is migrated to an active data storage device in a powered up state. The archive data storage device is then powering down.

Windage proximate to a spinning disk within a disk drive is directed through a plurality of apertures in a ramp situated near the outside diameter of the disk. A tab extending from a load beam that supports a slider rests on the ramp when the drive is not in use. When the drive is started the disk begins to spin and an actuator moves the load beam to bring the slider over the surface of the disk. As the load beam moves, the tab is guided along the ramp and cushioned by the air flow emerging from apertures in the ramp beneath it. When the drive is stopped the actuator brings the load beam back so that the tab engages the ramp. A cushion of air is again provided as the tab is moved along the ramp as the tab is returned to a parked position.

Nondestructive material condition monitoring and assessment is accomplished by placing, mounting, or scanning magnetic and electric field sensors and sensor arrays over material surfaces. The material condition can be inferred directly from material property estimates, such as the magnetic permeability, dielectric permittivity, electrical property, or thickness, or from a correlation with these properties. Hidden cracks in multiple layer structures in the presence of fasteners are detected by combining multiple frequency magnetic field measurements and comparing the result to characteristic signature responses. The threshold value for indicating a crack is adjusted based on a high frequency measurement that accounts for fastener type. The condition of engine disk slot is determined without removal of the disk from the engine by placing near the disk a fixture that contains a sensor for scanning through the slot and means for recording position within the slot. Inflatable support structures can be placed behind the sensor to improve and a guide can be used to align sensor with the slot and for rotating the disk. The condition of an interface between a conducting substrate and a coating is assessed by placing a magnetic field sensor on the opposite side of the substrate from the coating and monitoring at least one model parameter for the material system, with the model parameter correlated to the interfacial condition. The model parameter is typically a magnetic permeability that reflects the residual stress at the interface. Sensors embedded between material layers are protected from damage by placing shims on the faying surface. After determining the areas to be monitored and the areas likely to cause sensor damage, a shim thickness is determined and is then placed in at least one area not being monitored by a sensor. The condition of a test fluid is assessed through a dielectric sensor containing a contaminant-sensitive material layer. The properties of the layer are monitored with the dielectric sensor and correlated to contaminant level.

Embodiments of the invention provide a mounting structure adapted to easily attach and remove a magnetic disk drive thereto and therefrom. In one embodiment, the mounting structure includes a device connector connectable to an interface connector. A clamper moves between a fixing position and a releasing position to secure or release an end portion of a housing. A lever keeps the clamper at the releasing position until the interface connector is connected to the device connector when a magnetic disk drive is pushed into a mounting structure. The clamper positions the clamper at the fixing position after the interface connector has been connected to the device connector.

The invention discloses a two-fluid atomization nozzle which comprises a fluid joint, a liquid spinning disk, a two-fluid atomization cavity and a sprayer, wherein the sprayer is internally provided with a hollow cavity; one end of the hollow cavity is provided with an opening and the other end of the hollow cavity is provided with spray holes; the two-fluid atomization cavity, the liquid spinning disk and the fluid joint are sequentially assembled towards the opening in the hollow cavity; the two-fluid atomization cavity is internally provided with a first gas runner and a first liquid runner; an atomization cavity is formed at the junction of the first gas runner and the first liquid runner and is communicated with the spray holes; the liquid spinning disk is arranged at the liquid inlet end of the first liquid runner; the liquid joint is internally provided with a second gas runner and a second liquid runner. Therefore, the two-fluid atomization nozzle is formed by detachably assembling multiple split components, so that the replaceability of local atomization components is realized and the maintenance and replacement costs are lowered; furthermore, the two-fluid atomization nozzle can well ensure the high atomization rate and atomization degree of liquids.

Presented herein is a real-time target-locking confocal microscope that follows an object moving along an arbitrary path, even as it simultaneously changes its shape, size and orientation. This Target-locking Acquisition with Realtime Confocal (TARC) microscopy system integrates fast image processing and rapid image acquisition using, for example, a Nipkow spinning-disk confocal microscope. The system acquires a 3D stack of images, performs a full structural analysis to locate a feature of interest, moves the sample in response, and then collects the next 3D image stack. In this way, data collection is dynamically adjusted to keep a moving object centered in the field of view. The system's capabilities are demonstrated by target-locking freely-diffusing clusters of attractive colloidal particles, and actively-transported quantum dots (QDs) endocytosed into live cells free to move in three dimensions for several hours. During this time, both the colloidal clusters and live cells move distances several times the length of the imaging volume. Embodiments may be applied to other applications, such as manufacturing, open water observation of marine life, aerial observation of flying animals, or medical devices, such as tumor removal.

A hard disk drive includes a disk pack having at least one disk for recording and/or storing data and a spindle motor that support and rotates the disk, a base to which the disk pack is mounted, a cover that covers an upper surface of the base, and a respective filter disposed close to each of at least one of the major surfaces of the disk and extending in the radial direction of the disk including over at least an inner peripheral region of the disk. The filter has an absorbent layer capable of absorbing particles that come in contact with it. Particles on the surface of the disk, from the inner to the outer peripheral regions of the disk, are removed by the filter when the disk is rotated and the particles are flung off of the disk. Thus, particles will not damage the magnetic head(s) of the hard disk drive nor will the particles cause errors to occur in the recording and/or reproducing of data.

When attaching/detaching a magnetic disk drive to/from the slot of a PC card, the user holds the drive with his or her fingers and thumb, applying figure pressure to the portion of the drive in which the magnetic head is located, which might lead to damage to the magnetic head and the magnetic disk in the worst case. A magnetic disk drive according to one embodiment of the present invention comprises a magnetic disk, a spindle motor for holding and rotating the magnetic disk, a magnetic head for writing/reading information to/from the magnetic disk, an actuator having the magnetic head mounted on one end thereof, for moving the magnetic head in a radial direction of the magnetic disk, and a circuit board having electronic components thereon. A connector for transmitting signals from the magnetic head to an external device is attached to a side of the circuit board close to the magnetic head.

A method for measuring the clearance of a slider over a rotating disk by inducing a collision between the slider and the disk is described. After the normal flying height of the slider is established, the slider is driven into a collision with the rotating disk surface by applying a DC or AC voltage between the slider and the disk. The clearance data can be extracted from the induced collision by measuring a parameter, such as the change in the amplitude of the readback signal from the magnetic sensor, which is related to fly-height at the normal fly-height and at the disk surface. The two data points can then be used to derive the clearance. One embodiment uses a single beam interferometer to derive the vibrational displacement of the collision event.