| 摘要 |
PURPOSE:To improve the contrast of the signal of a prepit by specifying the distance between the surface of an intermediate coating layer coating the bottom part of the prepit and the surface of an intermediate coating layer coating the top part of the side wall of the prepit. CONSTITUTION:This recording medium consists of a recording layer 13 which is provided via the intermediate coating layer 12 on the prepit provided on the surface of a disk-shaped substrate 11 and permits writing and/or reading of information by laser. The distance (a) between the surface of the intermediate coating layer 12 coating the bottom part of the prepit and the surface of the intermediate coating layer 12 coating the peak part of the side wall of the prepit satisfies the conditions: lambda/10n<=a<=3lambda/20n with respect to the refractive index (n) of the substrate 11 and the wavelength lambda of the laser light to be used at the time of reading the information from the recording medium. The contrast of the signal in the prepit part is thereby improved. |
