Disk storage apparatus and method for adjusting head disk interference sensor threshold

摘要

According to one embodiment, a disk storage apparatus includes a disk, a slider, and a controller. The slider includes a head having a write element, a read element, and a head disk interference (HDI) sensor. The controller detects at least abnormality in vibration of the head based on an alternating current component of interference detected by the HDI sensor and an HDI sensor threshold. The controller further measures a characteristic of the HDI sensor and a flying height of the head and adjusts the HDI sensor threshold based on results of the measurements.

主权项

1. A disk storage apparatus comprising:
a disk comprising a plurality of tracks; a slider configured to fly over the disk, the slider comprising a head comprising a write element, a read element, and a head disk interference (HDI) sensor, the HDI sensor being configured to detect an alternating current component of interference acting between the head and the disk in an alternating current mode; and a controller configured to: detect at least abnormality in vibration of the head based on the detected alternating current component and an HDI sensor threshold; measure a characteristic of the HDI sensor and a flying height of the head, and characteristic of the HDI sensor including resistance of the HDI sensor; and adjust the HDI sensor threshold based on results of the measurements, wherein to adjust the HDI sensor threshold, the controller is configured to
calculate a first amount of change in the resistance of the HDI sensor based on the measured resistance and a pre-measured initial resistance of the HDI sensor,calculate a second amount of change in the flying height of the head based on the measured flying height and a pre-measured initial flying height of the head, andreflect the second amount of change in the HDI sensor threshold when an absolute value of the first amount of change is less than a first threshold and when an absolute value of the second amount of change is greater than a second threshold.