Patent ID: 8206805

Claim:
An optical recording medium comprising four information recording surfaces, the optical recording medium satisfying: t 3− t 4≧1 μm, t 4− t 2≧1 μm, t 2≧10 μm, and t 1−( t 2+ t 3+ t 4)≧1 μm, where t 1 is a thickness between a surface of the optical recording medium, and the first information recording surface closest to the surface of the optical recording medium, t 2 is a thickness between the first optical recording surface, and the second information recording surface second closest to the surface of the optical recording medium, t 3 is a thickness between the second optical recording surface, and the third information recording surface third closest to the surface of the optical recording medium, and t 4 is a thickness between the third optical recording surface, and the fourth information recording surface farthest from the surface of the optical recording medium.