Improvement of L/UL performance using load/unload mechanism control considering disk vibration characteristics

Abstract

Load/unload dynamic characteristics are affected by various parameters; load/unload speed, disk rotating speed, disk vibration and so on. The effect of load/unload process on various parameters was investigated by the experiment. As a result of experiment, the load performance was found to be better for lower load speed and disk rpm. On the other hand, it was confirmed to be better for lower unload speed and higher disk rpm in unload process. Also, the effect of disk vibration was studied for load/unload process. The amplitude of disk vibration can affect in a relative ramp-disk gap and the disk vertical velocity affects in a relative slider-disk speed during load/unload process. As the results of 1000 unload cycles, the non-contact region was changed as the function of disk rotating speed. The non-contact region was smaller in a lower disk rpm. This paper proposes a new control system in order to improve the load/unload performance.