Therefore, the process to construct the optical pickup device is easy, and thus, {HEAD ~ the errors generation ratio} of {TAIL ~ the optical pickup devices} is sharply decreased 
Therefore , the process to construct the optical pickup device is easy , and thus , { HEAD ~ the errors generation ratio } of { TAIL ~ the optical pickup devices } is sharply decreased
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH