Patent ID: 7609605

Claim:
An optical read/write apparatus, comprising: illumination means for supplying a read/write light beam; optical storage medium mounting means for supporting an optical storage medium such that said read/write light beam from said illuminating means strikes only a light-striking side of said optical storage medium, said optical storage medium including stacked data storage layers each of which is readable/writeable separately from the other layers by means of a light beam striking said light-striking side of said optical storage medium, wherein: said optical storage medium is structured and configured such that a recordable area of a first data storage layer including at least one recordable extended area portion is provided above a second data storage layer in a direction in which the first and second data storage layers are stacked, and said at least one recordable extended area portion extends in a radial direction of said optical storage medium past an entire recordable area of the second data storage layer, and, further, wherein said first data storage layer is located closest to said light-striking surface of said optical storage medium, and the second data storage layer is located next to the first data storage layer, away from said light-striking surface.