20110300325 | DISC SHAPED HIGH DENSITY RECORDING MEDIUM - This invention relates to an optical recording medium in which at least a recording layer and a light transmitting layer are sequentially formed on a substrate and in which the light is illuminated from the light transmitting layer side for recording and/or reproducing information signals, said substrate comprising an injection molded part, and said substrate having a Young's modulus E of at least 2.15 GPa and a Q factor of lower than 160 measured at 25° C. at 2000 Hz in accordance to ASTM E 756-05 05 and a transcriptability of the pit/groove structure of >85%. | 12-08-2011 |