PHASE CHANGE TYPE OPTICAL DISK

摘要

PURPOSE: A phase changing optical disk is provided to change the pattern of a recording mark so as to improve a recording/reproducing characteristic. The phase changing optical disk enables the improvement of a CNR(Carrier to Noise Ratio) according to write and erase power by having multi-pulse pattern, so that laser power necessary for erase and recording can be reduced and a recording sensitivity can be improved. CONSTITUTION: A plate(11) is arranged. The first dielectric layer(12) is formed on the plate(11). A recording layer(13) formed on the first dielectric layer(12) is capable of being converted into a substantial amorphous state and a substantial crystalline state. The second dielectric layer(14) is formed on the recording layer(13). A reflective layer(15) is formed on the second dielectric layer(14). A phase changing optical disk has a multi-pulse pattern, where preheating pulse, write pulse, multi pulse, last pulse and off pulse are sequentially divided, and has a recording mark, where a minimum size is 3T and a maximum size is 14T. The preheating pulse has 1/2T of wavelength time and 'Pe' of erasing power. The write pulse 3/2T or 2T of wavelength time and 'Pw' of writing power. And the off pulse has 1/2T of wavelength time and 'Pb' of bias power.