| 摘要 |
<p>It is an object to provide an address format that properly controls a recording line density and the number of information-recording layers for an information-recording medium to increase a recording capacity of the information-recording medium such as an optical disc in the range for making it possible to secure a necessary SN ratio. The optical disc is provided with an information-recording layer including concentric circles or spiral-shaped tracks, and has a format for describing track addresses recorded on a track in advance or added to data to be recorded on the information-recording layer. The format includes layer information on the information recording layers and address information on the track addresses. In a first optical disc having a first recording density, the layer information of the first optical disc is described by the first number of bits and the address information of the first optical disc is described by the second number of bits. In a second optical disc having a second recording density that is larger than the first recording density, the layer information of the second optical disc is specified by the number of bits that is less than the first number of bits and the address information of the second optical disc is specified by the number of bits that is more than the second number of bits. The total number of bits of the layer and address information of the second optical disc is equal to the sum of the first and second numbers of bits.</p> |
