As shown in FIG 1, an optical disk 11 is rotated by a motor 12, and duringthis rotation, {TAIL ~ data} is written to the optical disk 11 through an optical head 13, or {HEAD ~ data} recorded on the optical disk 11 is read through the optical head 13 
As shown in FIG 1 , an optical disk 11 is rotated by a motor 12 , and duringthis rotation , { TAIL ~ data } is written to the optical disk 11 through an optical head 13 , or { HEAD ~ data } recorded on the optical disk 11 is read through the optical head 13
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH