The determined PthO and the PcO are used to determine the write power threshold Pth that satisfies the equation Pth=PthO+PcO. The determined Pth value is, for instance, multiplied by the ratio {HEAD ~ α} between {TAIL ~ Popt} and Pth, which is set for each optical disc, to determine the optimum write power Popt 
between
The determined PthO and the PcO are used to determine the write power threshold Pth that satisfies the equation Pth = PthO+PcO. The determined Pth value is , for instance , multiplied by the ratio { HEAD ~ α } between { TAIL ~ Popt } and Pth , which is set for each optical disc , to determine the optimum write power Popt
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH