| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a pit shape which can easily raise information recording density of an optical disk. <P>SOLUTION: A PRML (Partial Response and Maximum Likelihood) system is used for reproduction of recorded information and the shortest pit is formed to a conical shape not having a base. The reproduction waveform of the shortest pit in the case of the PRML system is not required to largely take amplitude and therefore the pit may be conical. Since the conical pits can be recorded by packing the shortest pits even with the conventional master disk recording machine and master disk exposing process, the recording density in the frequency dividing direction can be increased. <P>COPYRIGHT: (C)2004,JPO |
