Patent ID: 7422838

Claim:
A phase-change optical recording medium comprising: a supporting substrate, and the following contiguous layers formed on said supporting substrate in the order recited, such as a first dielectric layer, a phase change recording layer, a second dielectric layer, a metal/alloy layer, and an ultraviolet light cured resinous layer; said phase change recording layer essentially consisting of Ag, In, Sb, Te and at least one additive selected from the group consisting of B, C, N, Si, Ge and Sn, with a proportion in atom percent of α(Ag):β(In):γ(Sb):δ(Te):θ(additive), with 0<α≦10, 2≦β≦12, 55≦γ≦70, 22≦δ≦32, and 0<θ≦5, provided that α+β+γ+δ+θ=100, wherein an uppermost recrystallization linear velocity of said phase change recording layer is from about 7.4 m/sec to about 10.0 m/sec; wherein the uppermost recrystallization linear velocity is determined by applying a DC mode laser beam having a 780 nanometer wavelength and a beam power ranging from 10 mW to 14 mW, to the recording medium, and measuring reflectivity values at groove or land portions in irradiated disk areas, through a pickup with an aperture of NA 0.5; wherein the substrate has a thickness of approximately 1.2 mm; wherein a thickness of the first dielectric layer is in a range from 65 nm to 130 nm, and said medium has a reflectivity of not less than 15% at each of wavelengths of 780 nm and 650 nm; and wherein jitter at a linear recording speed of higher than (CD4××)-speed is less than 35 ns.