Optical recording method for a rewritable phase-change optical recording medium

An optical recording method for recording information on a phase-change optical recording medium which is recordable at a low-linear-velocity and a high-linear-velocity greater than the low-linear-velocity, the optical recording method comprising the steps of:

• determining a ratio (Pel/Pwl) of an erasing power Pel to a recording power Pwl in the low-linear-velocity recording and a ratio (Peh/Pwh) of an erasing power Peh to a recording power Pwh in the high-linear-velocity recording so that the ratio (Pel/Pwl) and the ratio (Peh/Pwh) satisfy the relationship {(Pel/Pwl)<(Peh/Pwh)};
• and
• recording information on the phase-change optical recording medium and/or erasing information recorded on the phase-change optical recording medium by causing a change of phase in a recording layer of the phase-change optical recording medium by projecting a light beam onto the phase-change optical recording medium according to the recording power and the erasing power determined in the determining step;
• and
• wherein the determining step includes the step of determining the erasing power Pel and the recording power Pwl in the low-linear-velocity recording and the erasing power Peh and the recording power Pwh in the high-linear-velocity recording so that the ratio (Pel/Pwl) and the ratio (Peh/Pwh) satisfy the relationship {(Pel/Pwl)=B×(Peh/Pwh)}, where B≧0.45.

An optical recording method for recording information on a phase-change optical recording medium which is recordable at a low-linear-velocity and a high-linear-velocity greater than the low-linear-velocity, the optical recording method comprising the steps of:

• determining a ratio (Pel/Pwl) of an erasing power Pel to a recording power Pwl in the low-linear-velocity recording and a ratio (Peh/Pwh) of an erasing power Peh to a recording power Pwh in the high-linear-velocity so that the ratio (Pel/Pwl) and the ratio (Peh/Pwh) satisfy the relationship {(Pel/Pwl)<(Peh/Pwh)};
• recording information on the phase-change optical recording medium and/or erasing information recorded on the phase-change optical recording medium by causing a change of phase in a recording layer of the phase-change optical recording medium by projecting a light beam onto the phase-change optical recording medium according to the recording power and the erasing power determined in the determining step;
• and
• setting an Asymmetry (Asym) in the low-linear-velocity recording and in the high-linear-velocity recording so that the Asymmetry (Asyml) in the low-linear-velocity recording and the Asymmetry (Asymh) in the high-linear-velocity recording satisfy the relationship (Asyml<Asymh), where the Asymmetry (Asym) is a characteristic value defined by the following equation:
• Asym=[(3TH+3TL)/2−(11TH+11TL)/2]÷(11TH−11TL)
• where 3TH is a maximum value of an amplitude of a reproduction signal obtained from a shortest recording mark, 3TL is a minimum value of an amplitude of the reproduction signal obtained from the shortest recording mark, 11TH is a maximum value of an amplitude of a reproduction signal obtained from a longest recording mark, 11TL is a minimum value of an amplitude of the reproduction signal obtained from the longest recording mark.

An optical recording method for recording information on a phase-change optical recording medium which is recordable at a low-linear-velocity and a high-linear-velocity greater than the low-linear-velocity, the optical recording method comprising the steps of:

• determining a ratio (Pel/Pwl) of an erasing power Pel to a recording power Pwl in the low-linear-velocity recording and a ratio (Peh/Pwh) of an erasing power Peh to a recording power Pwh in the high-linear-velocity recording so that the ratio (Pel/Pwl) and the ratio (Peh/Pwh) satisfy the relationship {(Pel/Pwl)<(Peh/Pwh)};
• recording information on the phase-change optical recording medium and/or erasing information recorded on the phase-change optical recording medium by causing a change of phase in a recording layer of the phase-change optical recording medium by projecting a light beam onto the phase-change optical recording medium according to the recording power and the erasing power determined in the determining step;
• and
• setting an Asymmetry (Asym) in the low-linear-velocity recording so that the Asymmetry (Asyml) in the low-linear-velocity recording satisfies the relationship (Asyml≦−3.0), where the Asymmetry (Asym) is a characteristic value defined by the following equation;
• Asym=[(3TH+3TL)/2−(11TH+11TL)/2]÷(11TH−11TL)
• where 3TH is a maximum value of an amplitude of a reproduction signal obtained from a shortest recording mark, 3TL is a minimum value of an amplitude of the reproduction signal obtained from the shortest recording mark, 11TH is a maximum value of an amplitude of a reproduction signal obtained from a longest recording mark, 11TL is a minimum value of an amplitude of the reproduction signal obtained from the longest recording mark.

An optical recording method for recording information on a phase-change optical recording medium which is recordable at a low-linear-velocity and a high-linear-velocity greater than the low-linear-velocity, the optical recording method comprising the steps of:

• determining a ratio (Pel/Pwl) of an erasing power Pel to a recording power Pwl in the low-linear-velocity recording and a ratio (Peh/Pwh) of an erasing power Peh to a recording power Pwh in the high-linear-velocity recording so that the ratio (Pel/Pwl) and the ratio (Peh/Pwh) satisfy the relationship {(Pel/Pwl)<(Peh/Pwh)};
• recording information on the phase-change optical recording medium and/or erasing information recorded on the phase-change optical recording medium by causing a change of phase in a recording layer of the phase-change optical recording medium by projecting a light beam onto the phase-change optical recording medium according to the recording power and the erasing power determined in the determining step;
• and
• further determining the erasing power Pel and the recording power Pwl in the low-linear-velocity recording and the erasing power Peh and the recording power Pwh in the high-linear-velocity recording so that a difference (Pwl−Pel) and a difference (Pwh−Peh) satisfy the relationship {(Pwl−Pel)>(Pwh−Peh)};
• and
• wherein the step of further determining includes the step of determining the erasing power Pel and the recording power Pwl in the low-linear-velocity recording and the erasing power Peh and the recording power Pwh in the high-linear-velocity recording so that the difference (Pwl−Pel) and the difference (Pwh−Peh) satisfy the relationship {(Pwl−Pel)=C×(Pwh−Peh)}, where C≧1.1.

An optical recording method for recording information on a phase-change optical recording medium which is recordable at a low-linear-velocity and a high-linear-velocity greater than the low-linear velocity, the optical recording method comprising the steps of:

• determining a ratio (Pel/Pwl) of an erasing power Pel to a recording power Pwl in the low-linear-velocity recording and a ratio (Peh/Pwh) of an erasing power Peh to a recording power Pwh in the high-linear-velocity recording so that the ratio (Pel/Pwl) and the ratio (Peh/Pwh) satisfy the relationship {(Pel/Pwl)<(Peh/Pwh)};
• recording information on the phase-change optical recording medium and/or erasing information recorded on the phase-change optical recording medium by causing a change of phase in a recording layer of the phase-change optical recording medium by projecting a light beam onto the phase-change optical recording medium according to the recording power and the erasing power determined in the determining step;
• and
• further determining the erasing power Pel and the recording power Pwl in the low-linear-velocity recording and the erasing power Peh and the recording power Pwh in the high-linear-velocity recording so that a difference (Pwl−Pel) and a difference (Pwh−Peh) satisfy the relationship of {(Pwl−Pel)>(Pwh−Peh)};and
• wherein the step of further determining includes the step of setting the difference (Pwl−Pel) to be equal to or greater than 7.2 mW.

An optical recording method for recording information on a phase-change optical recording medium which is recordable at a low-linear-velocity and a high-linear-velocity greater than the low-linear-velocity, the optical recording method comprising the steps of:

• determining a ratio (Pel/Pwl) of an erasing power Pel to a Pel to a recording power Pwl in the low-linear-velocity recording and a ratio (Peh/Pwh) of an erasing power Peh to a recording power Pwh in the high-linear-velocity recording so that the ratio (Pel/Pwl) and the ratio (Peh/Pwh) satisfy the relationship {(Pel/Pwl)<(Peh/Pwh)};and
• recording information on the phase-change optical recording medium and/or erasing information recorded on the phase-change optical recording medium by causing a change of phase in a recording layer of the phase-change optical recording medium by projecting a light beam onto the phase-change optical recording medium according to the recording power and the erasing power determined in the determining step;
• and
• wherein a recording layer of said phase-change optical recording medium contains Ag, In, Sb, Te and N or O, and respective composition ratios α, β, γ, δ and ε of the elements satisfy the following relationships;
• 0<α≦6,3≦β≦15,50≦γ≦65,
• 20≦δ≦35,0≦ε≦10
• α+β+γ+δ+ε≦100.

An optical recording method for recording information, said optical recording method comprising the steps of:

• providing a phase-change optical recording medium which is recordable at a low-linear-velocity and a high-linear-velocity greater than the low-linear-velocity;
• providing a recording apparatus for recording information on said phase-change optical recording medium and for erasing information recorded on said phase-change optical recording medium, said apparatus being operable at said low-linear-velocity and at said high-linear-velocity;
• providing power setting for said recording apparatus such that said apparatus generates a first erasing power (Pel) and a first recording power (Pwl) for said low-liner-velocity, and a second erasing power (Peh) and a second recording power (Pwh) for said high-linear-velocity, wherein the ratio (Pel/Pwl) of said first erasing power (Pel) to said first recording power (Pwl) is less than the ratio (Peh/Pwh) of said second erasing power (Peh) to said second recording power (Pwh);
• subsequently, selecting one of said low-linear-velocity and said high-linear-velocity;
• and
• subsequently, operating said recording apparatus at said selected velocity and corresponding power settings.