| 摘要 |
PROBLEM TO BE SOLVED: To properly set the depth of the grooves of an optical recording medium provided with a shallow groove and a deep groove. SOLUTION: The optical recording medium is provided with a first recording track TrackA, a second recording track TrackB, a first groove 6 of a depth of d1 formed in a spiral shape along these first recording track TrackA and second recording track TrackB, and a second groove 7 of a depth d2 (d1<d2) formed along the first recording track TrackA and the second recording track TrackB so as to form a double spiral with the first groove 6. The depth d2 of the second groove is set to the depth d1 of the first groove by satisfying the condition that the AC component of a sum signal of a first optical detection output and a second optical detection output is 0.15 or smaller than a DC component. |
