| 摘要 |
A multiple-layer optical information recording medium is provided. An information recording layer that is the farthest from the reading side is denoted by L0, L1, L2, . . . and L5 information recording layers are successively formed in the direction of the optical axis. Five spacers having thicknesses t0 to t4 are interposed between the information recording layers. The spacers satisfy the relationships [Δtm>ACCT×Rm+1×Rm+2×Tm+12×nλ/(2NA2)] and [Δtm−sum>ACCT×Rm+a×Rm+b×Tab2×nλ/(2NA2)]. The thicknesses of the spacers of the six-layer disc satisfy the relationship t1>t3>t0>t2>t4. In addition, the thicknesses of the spacers are properly designated so that the influence of multiple reflections is removed. |
