| 摘要 |
PURPOSE:To maintain amplitudes of tracking error signals by forming guide grooves and performative pits under specific conditions. CONSTITUTION:The guide grooves and preformative pits in the optical disk 9 are formed so as to meet the requirements that the pitch of the guide groove 9A is one value from 1.4 to 2.0mum, the depth of the performative pit 9B ranges 0.46-0.58lambda/n, the vertical cross section of the guide groove 9A has a profile satisfying the first inequality F1(x)<y<F2(x) and the vertical cross section of the performative pit has a profile satisfying the second inequality G1(x)<y< G2(x). In these conditions, (n) represents the refractive index of the substrate 9b, lambda is the wavelength of the laser beam (nm), (x,y) in the first inequality represents a coordinate where the center point on the substrate between two guide grooves 9A is regarded as the original point and (x,y) in the second inequality represents a coordinate where the center of the guide groove 9A on the substrate is the original point. F1(x), F2(x), G1(x) and G2(x) are functions. Thus, the required amplitudes of tracking error signals can be maintained. |
