| 摘要 |
An information recording medium, comprising N number (N is an integer fulfilling N≧3) of information layers on which information is recordable, and allowing information to be recorded on each of the information layers and allowing information recorded on each of the information layers to be reproduced by being irradiated with laser light. The N number of information layers include an N′th information layer, an (N−1)th information layer, an (N−2)th information layer, . . . a second information layer and a first information layer sequentially located from a laser light incidence side. A reflectance of the N′th information layer is RN, and a reflectance of an M′th information layer (M refers to every integer fulfilling N>M≧1) is RM. The laser light used to irradiate the N′th information layer for reproducing information recorded on the N′th information layer has an upper limit reproduction power PrNmax, and the laser light used to irradiate the M′th information layer for reproducing information recorded on the M′th information layer has an upper limit reproduction power PrMmax. The following expressions (1) and (2) are concurrently fulfilled: RN>RM  (1) PrMmax<PrMmax  (2).
|
