Patent ID: 7394751
Filing Date: 2008-07-01
Classification: G11B

Abstract:
1. An optical storage system comprising an optical storage medium and an optical head device, the medium comprising a substrate having deposited on at least one side thereof: a recording stack having at least one recording layer for recording by means of a focused radiation beam, the focused radiation beam having a predetermined wavelength and a predetermined numerical aperture, emanating from the optical head device; and an optically transparent protective coating stack, between the recording stack and the optical head device, for protecting the recording stack from impact by the optical head device, characterized in that the protective coating stack comprises a multi-layer of at least: a first layer being present most remote from the recording stack, said first layer having a thickness smaller than 40 nm, and a surface with a surface energy smaller than 1.5 J/m a second layer adjacent the first layer, said second layer having a Young's modulus E smaller than 10 GPa and larger than 0.001 GPa.