y, of the disk device while a disk is loaded into the disk device or the disk is ejected from the disk device; FIGS. 3A and 3B are a plan view and a side view, respectively, of the disk device while the disk is accommodated therein and the driving unit is disposed at a retracted position; FIGS. 4A and 4B are a plan view and a side view, respectively, of the disk device while the disk is accommodat