Optical recording medium

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;
• 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,
• a sulfuration-inhibiting layer disposed above the upper protective layer;
• and
• a reflective layer disposed above the sulfuration-inhibiting layer,
• wherein a wobbled groove is formed on the transparent substrate, the wobbled groove having a track pitch of 0.740±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 SiO2, 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 SiO2, 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.

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;
• 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,
• a sulfuration-inhibiting layer having a thickness of 3 nm to 22 nm;
• 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 bead 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.

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;
• 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,
• a sulfuration-inhibiting layer comprising 90 mol % or more of Si and SiC disposed above said upper protective 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.

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;
• 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, wherein the interfacial layer contains ZrO2, TiO2, and at least one selected from rare-earth metal oxides and oxides of Group IIa elements of the Periodic Table of Elements except Be and Ra,
• 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.

An optical recording medium comprising:

• a transparent substrate;
• a lower protective layer formed over the transparent substrate;
• a recording layer formed over the lower protective layer;
• an upper protective layer formed over the recording layer;
• a sulfuration-inhibiting layer formed over the upper protective layer having a thickness of 3 nm to 22 nm;
• and
• an interfacial layer formed over the lower protective layer.

An optical recording medium comprising:

• a transparent substrate;
• a lower protective layer formed over the transparent substrate;
• a recording layer formed over the lower protective layer;
• an upper protective layer formed over the recording layer;
• a sulfuration-inhibiting layer comprising 90 mol % or more of Si and SiC formed over the upper protective layer;
• a reflective layer formed over the sulfuration-inhibiting layer;
• an organic protective film layer formed over the reflective layer;
• and
• an interfacial layer formed over the lower protective layer.