Patent ID: 7063875

Claim:
An optical recording medium comprising: a transparent substrate; a lower protective layer disposed above the transparent substrate; a recording layer containing a phase-change material, disposed above the lower protective layer; an upper protective layer disposed above the recording layer; and an interfacial layer disposed at least one of between the recording layer and the lower protective layer and between the recording layer and the upper protective layer; and a sulfuration-inhibiting layer formed over said upper protective layer; a reflective layer disposed above the sulfuration-inhibiting layer; an organic protective film layer formed over said reflective layer; wherein the optical recording medium has a transition linear velocity ranging from 8 m/s to 11 m/s as determined by irradiating continuous light with a power of 11±1 mW and a wavelength of 660±10 nm using a pickup head with a numerical aperture (NA) of 0.65, and satisfies the following condition: ΔR=|Rb—Ra|≦3% where ΔR is an absolute value of the difference between Ra and Rb; Rb is a reflectance of an unrecorded area, and Ra is a reflectance of the top of an eye pattern after ten cycles of recording, and wherein the optical recording medium is recordable with at least two recording modes of a first recording mode and a second recording mode, in which the first recording mode is that the optical recording medium is rotated at a constant angular velocity so as to have a linear velocity of 3 m/s to 4 m/s when recording on an innermost track of the optical recording medium and to have a linear velocity of 8 m/s to 9 m/s when recording on an outermost track of the optical recording medium, and the second recording mode is that the optical recording medium is rotated at a constant angular velocity so as to have a linear velocity of 5 m/s to 6 m/s when recording on an innermost track of the optical recording medium and to have a linear velocity of 13 m/s to 14 m/s when recording on an outermost track of the optical recording medium, and wherein a wobbled groove is formed on the transparent substrate, the wobbled groove having a track pitch of 0.74±0.03 μm, a groove depth of 22 nm to 40 nm, and a groove width of 0.17 μm to 0.30 μm, the lower protective layer contains a mixture of ZnS and SiO 2 , the phase-change material in the recording layer contains Sb and Te (as main components), the upper protective layer contains a mixture of ZnS and SiO 2 , the sulfuration-inhibiting layer contains at least one of Si and SiC, and the reflective layer contains at least one of Ag and Ag alloy.