HIGH DENSITY READABLE ONLY OPTICAL DISC AND METHOD OF PREPARING THE SAME

摘要

A HIGH DENSITY READABLE ONLY OPTICAL DISC INCLUDES A SUBSTRATE HAVING PITS (17) WITH DIFFERENT LENGTHS IN ACCORDANCE WITH UNIT INFORMATION, WHEREIN A DEPTH OF THE PIT INCREASES AS THE PIT LENGTH INCREASES; AND A MASK LAYER (11) THAT INCLUDES A METAL OXIDE, OR A MIXTURE OF FINE METAL PARTICLES (16) AND A DIELECTRIC MATERIAL. THE HIGH DENSITY READABLE ONLY OPTICAL DISC MAY BE USED TO READ PITS NOT GREATER THAN A READING RESOLUTION LIMIT AND TO OBTAIN AN OPTIMAL CNR SINCE A PIT DEPTH IS VARIED DEPENDING ON A PIT LENGTH. ALSO, A METHOD OF THE HIGH DENSITY READABLE ONLY OPTICAL DISC MAY BE USED TO PREPARE A HIGH DENSITY READABLE ONLY OPTICAL DISC HAVING AN OPTIMAL PIT DEPTH IN ACCORDANCE WITH A PIT LENGTH.FIGURE 3