| 摘要 |
<p>An optical disc includes a first to an n-th recording layer (13-1 to 13-n) and a first to an n-1-th intermediate layer (16) each sandwiched by two recording layers. When the thicknesses of the first to the n-1-th intermediate layer (16) at a position (r, ?) in a recording track region (14) are respectively d(r, ?, 1), d(r, ?, 2),..., d(r, ?, n-1), and the thickness of the m-th intermediate layer (1 = m = n-1) at the in-plane position (r, ?) has a maximum value d(m)max and a minimum value d(m)min, the following expressions are satisfied: d(m)max - d(m)min]/[d(m)max + d(m)min] = 0.05 and |d(r, ?, m) - d(r, ?, m-1) = 7 x P wherein P is the recording track pitch.</p> |
