Patent ID: 8553514

Claim:
An optical recording medium comprising: N recording layers (where N≧4); a number of kinds of layer intervals between the recording layers adjacent to each other being an integer M equal to or less than a minimum integer equal to or more than log 2 (N); and one or more blocks including four recording layers with a first layer interval, a second layer interval, and said first layer interval formed in order in the one or more blocks, wherein a number of the recording layers is such that said M as the number of kinds of layer intervals is M≧3, wherein the optical recording medium has each of parts of respective layer intervals from a third layer interval to an Mth layer interval as a layer interval between a recording layer forming said block and a recording layer adjacent to said recording layer, the adjacent recording layer being included in other than the block including said recording layer, and wherein said first layer interval<said second layer interval<the third layer interval< . . . <the Mth layer interval.