摘要:
The present invention provides a disk drive, a loading/unloading apparatus, and a method for controlling the apparatus, capable of improving the reliability of data by performing stable speed control. A disk drive comprises a VCM spindle driver for rotating a disk, a magnetic head, an actuator mechanism for moving a head slider having the magnetic head to a position above the surface of the magnetic disk and an unloaded position, a ramp block, and a CPU/HDC for performing the speed control of an actuator and the calibration control for detecting the offset and dynamic range of an AD converter before the speed control and controlling the operation for reading or writing data from or into the disk, which increases a rectangular current value to be applied to a voice coil while successively changing codes, measures an offset in accordance with the AD converter value for each current value, and moreover measures a dynamic range by deciding a nonlinear area when the difference between the expected value and measured value of the AD converter becomes a predetermined value or more.
摘要:
A disk drive with means to prevent accidental landing of a head/slider on the disk surface is described. In one embodiment a shock sensor is provided to sense external shocks received by the mechanism. During loading (positioning) of the actuator bearing the head/slider over the disk, if a shock is sensed, loading is stopped and an immediate unloading is performed to return the actuator to the withdrawn position. In another embodiment the unload operation is performed when the rotational speed of the disk is changed. In another embodiment the unload operation is performed when the rotational speed of the disk drops below a threshold. A circuit and method for detecting when the rotational speed of the disk drops below a threshold is also provided. The unloading in the various embodiments may be performed using velocity control or without velocity control.
摘要:
The invention relates to a head mechanism control apparatus for magnetic recording device which ensures that the transducer head has been unloaded in a head unloading operation. A head slider having a transducer head is mounted on a head arm and is unloaded from the disk by the swinging of the head arm. The retract position is at the limit portion of the swingable range of the head arm. When the head slider is successfully unloaded to the retract position, a drive force applied to the head arm in the unload direction causes little movement of the head arm. After an unloading is performed, a position check drive force is applied to the head arm and the moving speed of the head slider is detected. Based on the moving speed, it is judged whether the head slider has been unloaded to the retract position. If the head slider has not been unloaded to the retract position, re-unloading is performed for moving the head slider to the retract position.
摘要:
The invention relates to a magnetic recording device which can be used at a reduced atmospheric pressure without having the head/slider assembly stick to the disk. A method of the present invention for controlling the operation of a disk drive device in reduced atmospheric pressure where a read/write head mounted on a head support arm flies above the surface of a rotating recording disk. The head support arm is moved along a radial direction of the recording disk to position the read/write head to one of cylinder positions of the recording disk. The method comprises steps of (i) detecting a value of the reduced atmospheric pressure during a power on reset period before a read/write period, (ii) storing information indicating whether the detected value of atmospheric pressure is lower than a threshold value, and (iii) accessing, during the read/write period, the stored information to determine whether an operation for lowering a flying height of the read/write head to a height which is lower than a height for the read/write operation should be inhibited.
摘要:
A disk drive apparatus and read error recovery method in a disk drive apparatus removes thermal asperities on disk surfaces. A projection, such as a thermal asperity, on the recording surfaces of disks is detected when a signal transducer contacts the projection. The flying height of the signal transducer is lowered, e.g., by reducing the disk rotation speed from the normal rotation speed in read/write operations, while the signal transducer is positioned over the detected projection on the track. The signal transducer strikes the projection to break the projection. This avoids a subsequent error from being caused by the thermal asperity.
摘要:
A method to enable servo information to be detected surely and stably even when a time interval between servo sectors is changed due to disk shifting. A time interval TS(i) is calculated according to an internal variable value, which is in proportion to a displacement &Dgr;r(i) of a servo area SF(i) in a radial direction of a subject disk (step S6). The displacement &Dgr;r(i) is calculated from already detected servo information[, thereby]. Thereby, a time interval for detecting servo information is adjusted according to the above described time interval TS(i) (steps S7 and S4). The time interval TS(i) is the time interval between passing of a servo sector in the servo area SF(i) under the head H and passing of a servo sector in the servo area SF(i+1) under the head H.
摘要:
A disk drive apparatus and read error recovery method in a disk drive apparatus removes thermal asperities on disk surfaces. A projection, such as a thermal asperity, on the recording surfaces of disks is detected when a signal transducer head contacts the projection. The flying height of the signal transducer head is lowered, e.g., by changing the disk rotation speed from the normal rotation speed in read/write operations or by heating a suspension having a bimetal element, while the signal transducer head is positioned over the detected projection on the track. The signal transducer head strikes the projection to break the projection. This avoids a subsequent error from being caused by the thermal asperity.
摘要:
A disk drive. The disk drive includes a head, a moving mechanism, a first peak filter, an adaptive peak filter, and a filter controller. The head is configured to read servo data on a disk at sampling frequency. The moving mechanism is configured to move the head in proximity with a recording surface of the disk. The first peak filter has a fixed peak frequency and a variable gain, and is configured to be inserted into a servo loop. The servo loop is configured to position the head with position error signals between servo data read by the head and a target position. The adaptive peak filter has a variable peak frequency and a variable gain, and is configured to be inserted into the servo loop. The filter controller is configured to control the gain of the adaptive peak filter according to the gain of the first peak filter.
摘要:
A method (and structure) senses a rotational vibration of a disk drive. The disk drive includes a rotating disk. The disk includes a plurality of reference bits across a surface thereof. The method (and structure) includes detecting the reference bits across a pattern on the rotating disk, and analyzing a time interval between adjacent ones of the reference bits.
摘要:
Embodiments in accordance with the present invention provide a magnetic disk drive with reduced noise during seek operation without causing any delay in control response. According to one embodiment of the present invention, a control circuit of a magnetic disk drive controls the drive power supplied to a voice coil motor during a seek operation adapted to move a magnetic head over a target track formed on a magnetic disk so as to bring the travel speed of the magnetic head close to a predetermined target speed. The control circuit determines a provisional current according to the difference between the predetermined target speed and an actual travel speed in an acceleration zone adapted to accelerate the magnetic head to the predetermined target speed. If the provisional current exceeds a limit specified in relation to an elapsed time from the start of acceleration, the control circuit sets the limit as the current of the drive power supplied to the voice coil motor to control the motor.