Optical recording medium and optical disk apparatus

摘要

An optical recording medium according to the present invention includes a base layer having an information signal portion formed on a surface on the side on which laser light is incident, and a light transmissive layer formed on the base layer. A thickness t of the light transmissive layer is within the range of t = 3 to 177 mu m at least in an area of the information signal portion. If unevenness of the light transmissive layer is DELTA t, N.A. of an optical system for reproduction or recording and reproduction and a wavelength lambda satisfies DELTA t ≤ +/- 5.26 ( lambda /N.A.<4>) ( mu m). A track pitch is P and a skew is THETA , then P ≤ 0.64 mu m and THETA ≤ +/-84.115 DEG ( lambda /N.A.<3>/t) are satisfied. The optical recording medium is recorded or reproduced by a recording and reproducing system satisfying lambda ≤ 0.68 mu m and N.A./ lambda ≥ 1.20. The optical recording medium permits a recording capacity of 8 GB.