Patent ID: 7821910
Filing Date: 2010-10-26
Classification: G11B

Abstract:
1. An optical disc, comprising tracks, each divided into a plurality of recording blocks; wherein: each of the plurality of blocks includes a run-in area and a data area; in the run-in area, a prescribed run-in bit pattern is recordable; in the data area, bit patterns having a plurality of bit lengths obtained by modulating data as a recording target in accordance with a prescribed modulation rule are recordable; at least one of spatial frequencies corresponding to the bit patterns having the plurality of bit lengths in accordance with the prescribed modulation rule is higher than a cutoff frequency; the cutoff frequency is defined as a frequency at which a gain of an optical transfer function (OTF) is 0 times; and the run-in bit pattern recordable in the run-in area includes the bit patterns having the plurality of bit lengths, from which the bit pattern corresponding to the frequency higher than the OTF cutoff frequency has been excluded.