Patent ID: 6091580
Filing Date: 2000-07-18
Classification: G11B

Abstract:
A method of reducing a byte error rate of data reproduced from an optical disc arising from corrosion of a functional layer of the optical disc, comprising:forming an optical disc, the disc including a substrate, a functional film arranged over the substrate, and a protective film arranged over the functional film, wherein the protective film has a maximum film thickness d at an outer periphery of the protective film and a mean film thickness d.sub.0 at a flat portion of the protective film on a data area of the disc which are related by2d.sub.0 .ltoreq.d.ltoreq.d.sub.0 +40 mm;recording data on the functional layer of the optical disc;reproducing the data recorded on the optical disc; andexposing said optical disk to high temperature and humidity conditions for a predetermined time, wherein the byte error rate of said optical disc is less than or equal to 1.0.times.10.sup.-5 after being exposed to said high temperature and humidity conditions.