Patent ID: 8144566

Claim:
An information storage medium with n information storage layers (where n is an integer that is equal to or greater than three), on which data can be written with a laser beam and which are stacked one upon the other, wherein each of the n information storage layers has a test write zone for determining the recording power of the laser beam, and wherein when those n information storage layers are counted from the one that is located most distant from the surface of the medium on which the laser beam is incident, there is a bigger radial location difference between the inner peripheral end of the inner one of the test write zones of kth and (k+1)th information storage layers (where k is an integer that satisfies 1≦k≦n−2) and the outer peripheral end of the other outer test write zone than between the inner peripheral end of the inner one of the test write zones of kth and (k+2)th information storage layers and the outer peripheral end of the other outer test write zone.