Optical recording medium, information recording or reproducing method, and information recording or reproducing apparatus

摘要

An optical recording medium improves the quality of servo signals and readout signals by preventing light convergence on the back of the surface of the optical recording medium and reducing interference of light reflected from recording surfaces of the optical recording medium. An optical recording medium 40 includes at least three information recording surfaces, and satisfies d 1 <(d 4 -d 1 ), where d 1 is a distance from a surface 40 z of the optical recording medium 40 to a first information recording surface 40 a that is nearest to the surface 40 z and d 4 is a distance from the surface 40 z to a fourth information recording surface 40 d that is most distant from the surface 40 z, and satisfies dmin>= 8 mum, where dmin is a minimum interlayer thickness between the at least three information recording surfaces.