摘要:
When an idle seek operation of a magnetic disk drive is executed under a velocity control utilizing a back electromotive force of a VCM actuator, the accuracy of the velocity control is deteriorated due to temperature variation of the VCM. To eliminate this disadvantage, a calibration of the velocity control is executed by using control information, such as a track number read from the magnetic disk medium. After the velocity control has been executed for an appointed period, by detecting the back electromotive force from the VCM actuator, an MR sense current and a power of a read write LSI are turned on for a time, positioning information on the magnetic disk medium is read out, parameters to be used for the velocity control are calibrated, and thus a stability of the control can be obtained. Hereby, because the positioning information on the magnetic disk medium is not used constantly, the power consumption during the idle seek operation is reduced, and a stable control of the movement can be obtained as well. For a portable system such as a notebook type personal computer in which a magnetic disk drive is employed, the operation is improved with respect to the use of a battery.
摘要:
To control load/unload operation of a slider with magnetic head mounted thereon, by which the speed can always be controlled stably while avoiding the slowdown or temporary stop of an actuator during load/unload operation, a magnetic disk drive is configured using magnetic disk media with the servo information written therein beforehand up to the track located at a position corresponding to the landing zone for the load operation of the magnetic head (slider). The speed of the magnetic head (slider) withdrawn to the ramp is controlled at the unload operation. In the stage of initialization for controlling the speed of the load/unload operation, various parameters are recorded and updated to apply a voltage to power amplifier for compensating for the external forces caused by the friction mainly exerted between ramp and slider support members, with reference to the take-off track or the landing track specified in the landing zone.
摘要:
In a magnetic disk device and other memory devices, the scale and cycle of disturbance applied to each memory device are monitored to make a distinction between a harmful shock and harmless vibrations and detect the disturbance. Values at at least two points, of a waveform signal corresponding to the disturbance are captured. A) The above distinction is carried out from the size or magnitude of the inclination of a straight line defined by the two points. B) The function of capturing and storing the waveform signal corresponding to the disturbance as digital data, and outputting a slice level value for providing suitable detection sensitivity from a conversion table based on the digital data, or correcting and adjusting it and outputting the result is further set.