Abstract: A spin up procedure for use with a DC brushless motor uses a variable rotor position sampling interval during the early stages of rotor acceleration. Prior to applying a drive current to the motor, the present position of the rotor with respect to the stator is sensed. Once the initial rotor position is known, a selected drive current state is applied to the stator coil windings to initiate motion of the rotor. While the rotor accelerates, rotor position samples are repeatedly taken to provide the needed position feedback for commutation purposes. The rotor position samples are taken using a decreasing sampling interval during the rotor acceleration phase. Preferably, the rotor position update rate roughly tracks the increasing rotational velocity of the rotor during the spin up operation.

Abstract: A system having a storage device including read/write heads for repositioning the read/write heads from a parking location to a position adjacent a surface of a magnetic disk, the storage device includes a spindle motor coupled to the magnetic disk, for accelerating the magnetic disk to at least a first number of revolutions per time period while the read/write heads are positioned at the parking location, and a solenoid control coupled to the read/write heads and to the spindle motor, for biasing the read/write heads towards the position adjacent the surface of the magnetic disk after the magnetic disk reaches the first number of revolutions per time period, wherein the spindle motor maintains a rotation of the magnetic disk at less than a second number of revolutions per time period before the read/write heads are positioned adjacent the surface of the magnetic disk, and wherein the spindle motor rotates the magnetic disk at a third number of revolutions per time period after the read/write heads are positi

Abstract: There are provided a magnetoresistive sensor of the type of flowing a signal sensing current perpendicular to the plane to improve resolution at reproducing a signal, a magnetic head using the magnetoresistive sensor, and a magnetic disk apparatus.

Abstract: The device is for driving and controlling a rotation motor and a voice coil motor for a hard disk drive system that includes a disk and an arm carrying a read/write head to be positioned with respect thereto. A duty-cycle control loop including a current sensing circuit is connected to the voice coil motor, and an arm position control loop including a speed detection circuit is also connected to the voice coil motor. The duty-cycle control loop and the arm position control loop are digitally implemented by a DSP as a function of digital data representing a first analog signal generated by the current sensing circuit representative of current conducting in a winding of the voice coil motor, and a second analog signal generated by the speed detection circuit representative of an instant speed of the voice coil motor.

Abstract: An electronic device for driving an actuator device for a hard disk and a motor for turning the hard disk, the device having a first driving circuit connected to the rotation motor and integrated in a chip of semiconductor material having a substrate defining a reference-potential region, a second driving circuit integrated in the chip and connected to a first actuation stage of the actuator device, and a third driving circuit integrated in the chip and connected to a second actuation stage of the actuator device. The actuator device supports a read/write transducer of the hard disk. The first actuation stage performs a rough displacement of the read/write transducer, while the second actuation stage performs a finer displacement of the same read/write transducer.

Abstract: The present invention provides a magnetic recording apparatus for recording/reproducing a data with a comparatively high density. The magnetic recording apparatus comprises: a magnetic recording medium having a data area and a spare area; a head for data write in the data area with a predetermined recording frequency; a head error detection circuit for detecting a head error during a data write; and a controller that operates as follows. When an error is detected by the head error detection circuit, a data write is carried out in the spare area and if this does not cause an error, it is decided that the head is normal.

Abstract: In a device for controlling rotation of a disk, if a determination is made that a signal is not normally detected by a pre-pit-region detection circuit, an error signal is obtained from a pulse generator to control the rotation of the disk. If a determination is made that a signal is normally detected by the pre-pit-region detection circuit and if the synchronizing signals are not normally detected at predetermined intervals, an error signal is obtained from the wobble signal so that the rotations of the disk are controlled. If a determination is made that synchronizing signals are detected by the pre-pit-region detection circuit at predetermined intervals, an error signal is obtained from clocks synchronized with the reproduced signal generated by the PLL circuit so that rotations of the disk are controlled.

Abstract: It is an object of the present invention to improve reliability to a dust or the like of a magnetic disk device. The magnetic disk device of the present invention comprises a magnetic disk 10, a levitation type magnetic head slider 12 and a controller 14 for controlling an operation of the magnetic head slider 12 and the controller 14. The controller 14 moves the magnetic head slider 12 to a CSS (Contact Start Stop) region of the magnetic disk 10 at a predetermined time interval and performs a CSS operation at least once.

Abstract: A magnetic disk apparatus includes a spindle motor for rotating a magnetic disk. Either a first pulse-train signal or a second pulse-train signal is selectively generated. The first and second pulse-train signals are different from each other in pulse frequency. When the first pulse-train signal is generated, the spindle motor is controlled to rotate at a first rotational speed in response to the first pulse-train signal. When the second pulse-train signal is generated, the spindle motor is controlled to rotate at a second rotational speed in response to the second pulse-train signal. The second rotational speed differs from the first rotational speed.

Abstract: The present invention aims to provide a disk drive apparatus in which a pickup is prevented from being overheated. The disk drive apparatus includes a motor for rotating a disk-shaped storage medium, a pickup for reading/writing information from/onto the storage medium, a rotation controller for controlling the rotational speed of the storage medium, and an overheat detector for detecting overheating of the pickup. The pickup is cooled by using an airflow entailed by the rotating storage medium. In the disk drive apparatus, when the overheat detector detects overheating of the pickup, the rotation controller increases the rotational speed of the storage medium, thereby increasing the efficiency of cooling the pickup.

Abstract: A system having a storage device including read/write heads for repositioning the read/write heads from a parking location to a position adjacent a surface of a magnetic disk, the storage device includes a spindle motor coupled to the magnetic disk, for accelerating the magnetic disk to at least a first number of revolutions per time period while the read/write heads are positioned at the parking location, and a solenoid control coupled to the read/write heads and to the spindle motor, for biasing the read/write heads towards the position adjacent the surface of the magnetic disk after the magnetic disk reaches the first number of revolutions per time period, wherein the spindle motor maintains a rotation of the magnetic disk at less than a second number of revolutions per time period before the read/write heads are positioned adjacent the surface of the magnetic disk, and wherein the spindle motor rotates the magnetic disk at a third number of revolutions per time period after the read/write heads are positi

Abstract: An apparatus and method for minimizing the effects of rotational vibration upon a disc drive having a base deck supporting a rotatable disc and an actuator having a moveable data head. A fixed head is supported over the disc at a predetermined radius and transduces a circumferentially extending frequency pattern written to the disc at a constant frequency to generate a readback signal. A frequency modulation (FM) demodulator generates a rotational velocity signal indicative of application of rotational vibration to the base deck in relation to changes in frequency of the readback signal. A servo circuit controllably positions the moveable data head in response to the rotational velocity signal and servo information readback by the moveable data head. The servo circuit interrupts a data transfer operation between the moveable data head and a host device when a magnitude of the rotational velocity signal exceeds a predetermined threshold.

Abstract: A method and apparatus for reducing the amount of time from a power-on status to a ready status of a hard disk drive device. In response to a power-on of a disk drive device, the rotation of a data recording disk is started. The rotational speed of the data recording disk is increased. When it is detected that the rotational speed of the data recording disk reaches an intermediate rotational speed, which is lower than a final rotational speed of the data recording disk, the rotational speed of the data recording disk is fixed at the intermediate rotational speed. One or more control programs recorded on the data recording disk are read and then stored in a memory. Then a ready signal is sent to a host processor. The disk drive device may then receive a read command from the host processor to read data from the data recording disk and to transfer the data to the host processor is detected.

Abstract: A motor rotates a recording medium of a disk cartridge loaded in a disk device. A disk-type detecting unit detects whether the recording medium of the disk cartridge loaded in the disk device is a high-capacity recording medium or a low-capacity recording medium. A motor driving controlling unit causes the motor to rotate in accordance with a given reference clock signal, the motor driving controlling unit being set to a first mode for rotating the motor at a first rotation speed when the disk-type detecting unit detects that the recording medium of the loaded disk cartridge is the low-capacity recording medium and being set to a second mode for rotating the motor at a second rotation speed when the disk-type detecting unit detects that the recording medium of the loaded disk cartridge is the high-capacity recording medium, the second rotation speed being higher than the first rotation speed.

Abstract: In a magnetic disk unit having a load/unload function of a magnetic head for a magnetic disk, the magnetic disk and the magnetic head are prevented from contacting with each other and damage thereto is avoided by utilizing a shallow dual-step subambient pressure slider and carrying out loading/unloading at a rotational speed lower than a rated rotational speed of the normally operated magnetic disk at which writing and reading (R/W) data to and from the magnetic disk by the magnetic head is done.

Abstract: A disk drive includes a disk having data tracks including servo sectors and data regions disposed between the servo sectors. A transducer head writes data to and reads data from the data regions and reads servo information from the servo sectors. A spindle motor rotates the disk. A spindle motor driver provides current to the spindle motor. A track-following controller is responsive to the servo information for causing the transducer head to remain on track. A microprocessor performs a power-saving idle operation of causing the spindle motor driver to sequentially (1) provide no current to the spindle motor for at least one disk revolution and (2) provide current to the spindle motor for at least one disk revolution. The power-saving idle operation is performed while the track-following controller causes the transducer head to remain on track for multiple disk revolutions.

Abstract: A server hard disk drive integrated circuit (12) is provided for controlling the operation of a server hard disk drive (10) and for processing digital data exchanged between a client (20) and a storage media. The storage media includes a spindle motor for rotating a magnetic disk and a head actuator for positioning a read/write head. The server hard disk drive integrated circuit (12) includes a RAM (30), a disk control circuitry (24), write channel (32), a read channel (34), a servo circuit (36), a motor control circuit (40), and a DSP (26). The disk control circuitry (24) receives and stores requests provided from the client (20) and exchanges digital data with the client (20) and stores the digital data in RAM (30). The write channel (32) generates a write signal during a write operation, and the read channel (34) generates a read signal and an intermediate read signal during a read operation.

Abstract: In a disk drive system a servo controller is responsive to a position signal and operative to determine values for servo parameters during each of a plurality of sampling intervals, and is also operative to update a spindle command signal and an actuator command signal during sampling intervals for controlling seeking operations including an acceleration sequence and a deceleration sequence for positioning a head at a target track. The controller is further operative to implement a process of limiting the current drawn by a supply during periods of the deceleration sequence. The spindle command signal is regulated to adjust a spindle current to a reduced value which is less than a nominal value during a spindle energy deferring period while an actuator current exceeds a predetermined threshold value.

Abstract: The presence of a disk cartridge in a disk drive is detected by obtaining a measure of the load on the spindle motor of the disk drive and comparing that measure to a threshold value. The measure of load on the spindle motor may comprise (i) the time the spindle motor takes to spin-up to its full operating speed, (ii) the time the spindle motor takes to coast down to its operating speed from a first speed in excess of the operating speed, (iii) the voltage applied across the coils of the spindle motor, or (iv) the current drawn by the spindle motor.

Abstract: A method and apparatus are disclosed for optimizing operational performance of a disc drive. The disc drive is provided with an integrated temperature measurement circuit which provides a temperature measurement signal indicative of operational temperature of the disc drive. The integrated temperature measurement circuit is formed as part of an application specific integrated circuit (ASIC) housing additional circuitry used by the disc drive during operation. A parametric configuration circuit, operably coupled to the integrated temperature measurement circuit, identifies selected parameters for use by the disc drive to optimize disc drive performance, the parameters arranged as a plurality of parameter sets corresponding to a plurality of predefined operational temperature ranges.

Abstract: An information handling system, such as a disk drive, includes a base, a disk stack rotatably attached to the base, and an actuator assembly movably attached to the base. The actuator assembly also includes a load spring and a slider attached to said load spring. A ramp is also attached to the base near the disk stack. The ramp is used to load and unload the sliders to and from the disk. The slider and load spring are attached to form a gimballing connection between the slider and the load spring. The disk drive also includes a spindle motor and spindle motor controller for rotating the disk at a first rotational velocity and for rotating the disk at a second rotational velocity. The slider includes an air bearing surface. Landing pads, made of a durable material such as diamond like carbon, are formed on the air bearing surface of the slider. A method for loading a slider from a ramp to a disk surface includes rotating the disk at a first rotational velocity, as the slider is loaded.

Abstract: A disc driving device for accommodating a disc-type recording medium (for example, a floppy disc) that provides reliable chucking and centering of the disc-type recording medium. The disc-type recording medium that is accommodated in the disc driving apparatus has a hub with a center opening, a chuck hole at a predetermined distance from the center opening, and a recording disc attached to the hub. The disc driving device includes a disc table with a major surface for loading the hub, a spindle shaft for fitting in the center opening, a chuck member for rotation and fitting in the chuck hole, a spindle motor for rotating the disc table, a head for recording and/or reproducing information signals for the recording disc loaded on the disc table, a cartridge holder for moving the recording disc between a loading position and an unloading position, and a system controller for controlling the rotational velocity of the disc table.

Abstract: In a recording/reproduction apparatus, when a rotational-speed-mode setting instruction is received from an I/F unit, a CPU reads out a control procedure from a storage device, controlling other components in accordance with the procedure. As a result, a node switch driving circuit controls field windings of a pulse motor to a switching sequence, driving the pulse motor to rotation at a predetermined rotational speed. Since the control is feedback control, the pulse motor rotates at the predetermined rotational speed specified by an instruction setting a rotational-speed mode with a high degree of reliability. Data can thus be recorded into and reproduced from a magnetic disk at a variable speed.

Abstract: In a recording/reproduction apparatus, when a rotational-speed-mode setting instruction is received from an I/F unit, a CPU reads out a control procedure from a storage device, controlling other components in accordance with the procedure. As a result, a node switch driving circuit controls field windings of a pulse motor to a switching sequence, driving the pulse motor to rotation at a predetermined rotational speed. Since the control is feedback control, the pulse motor rotates at the predetermined rotational speed specified by an instruction setting a rotational-speed mode with a high degree of reliability. Data can thus be recorded into and reproduced from a magnetic disk at a variable speed.

Abstract: A compact disc automatic phonograph which records skips which occur during playing of a selection as well as cancellations of selections which occur as a result of the player not being able to read a disk, an excessive skip time or an excessive number of skips, as well as the times of occurrence of skips and cancellations for later review. Autoplayb and free play features may be set in terms of hours of the day and days of the week. Selections which have been made but not yet played may be cancelled after a predetermined interval following the time the phonograph has been turned off.

Abstract: In a motor drive for driving a motor having three-phase coils in both a high rotation speed mode in which the motor rotates at a high rotation speed and a low rotation speed mode in which the motor rotates at a low rotation speed which is extremely lower than the high rotation speed, the motor drive includes a mode selection circuit for making a connection of the three-phase coils unipolar and bipolar connections on the high and the low rotation speed modes, respectively. A frequency generation pattern detects a rotation speed of the motor. On the basis of the rotation speed detected by the frequency generation pattern, a combination of a PLL circuit and a driving transistor drives the motor at the high and the low rotation speeds in the high and the low rotation speed modes, respectively.

Abstract: A disk drive employs a method of operating a spindle motor to respond to a spin-down command to reduce the time required for subsequently responding to a spin-up command. After receiving the spin-down command, and while the rotor continues to spin in the forward-spin direction, a state machine is set to and maintained in a first predetermined register state such that a controlled rotor-stopping operation is performed. At the end of the controlled rotor-stopping operation, the rotor angle is within the range of a peaked forward direction waveform for a second predetermined register state of the state machine.

Abstract: A mass storage peripheral device for use with a host computer has a rotating data medium with a motor arranged to rotate it. A sensor reads information from the medium, and a data preamplifier for amplifies the read information. An interface is connected between the mass storage peripheral device and the associated computer. The interface includes a data transmission path to conduct data signals from the data amplifier to a controller circuit for the peripheral device in the host computer. The mass storage peripheral device may also include a circuit path to receive motor control and drive signals from the host computer for operating the motor. The peripheral device may be adapted to receive motor control signals from a servo circuit, which is preferably located in the host computer and connected to the interface for operating the motor. A read channel circuit is connected to receive the amplified data signal, also may be located in the host computer.

Abstract: A technique for reading data from a magnetic disk includes the steps of providing the magnetic disk including a cylinder having a plurality servo sectors, a plurality of data sectors, and a zone data table, the plurality of servo sectors including a first servo sector, a second servo sector, a third servo sector, a fourth servo sector, and a fifth servo sector, the zone data table including at least a nominal timing latency between the fourth servo sector and a data sector from the plurality of servo sectors, reading the first servo sector, the second servo sector, the third servo sector, and the fourth servo sector from the magnetic disk, determining a first timing deviation for the first servo sector between the first servo sector and the second servo sector, determining a second timing deviation for the second servo sector between the second servo sector and the third servo sector, predicting a predicted third timing deviation for the fourth servo sector between the fourth servo sector and the fifth servo

Abstract: It is an object of the present invention to improve reliability to a dust or the like of a magnetic disk device. The magnetic disk device of the present invention comprises a magnetic disk 10, a levitation type magnetic head slider 12 and a controller 14 for controlling an operation of the magnetic head slider 12 and the controller 14. The controller 14 moves the magnetic head slider 12 to a CSS (Contact Start Stop) region of the magnetic disk 10 at a predetermined time interval and performs a CSS operation at least once.

Abstract: A method for driving the motor of multiple phase, where the number of windings in the coil of each phase can be changed, either in a first mode where all the windings in the coil of each phase are used or a second mode where the number of windings used is smaller than that of the first mode. The driving method includes a source voltage detector for supplying the driving method with a source voltage, a temperature detector for detecting an ambient temperature about the motor, and a controller for switching the action of the driving method to run the motor in either the first mode or the second mode in response to a result of the detection released from the source voltage detector or the temperature detector. Accordingly, the revolution of the motor can be maintained constant hence providing a degree of energy saving.