摘要:
An optical phase-change disc comprises a substrate having thereon a spiral groove or concentric grooves for guiding a focused light beam, and a layer structure including a recording layer and protective layers sandwiching therebetween the recording layer. The groove has wobble for recording ATIP (absolute time information) or ADIP (address information). The following relationship between the groove width GW, beam diameter R.sub.0 and wobble amplitude a.sub.w :0.25.ltoreq.GW/R.sub.0 .ltoreq.0.45or0.65.ltoreq.GW/R.sub.0 ;and0.03.ltoreq.a.sub.w /GW.ltoreq.0.08hold for preventing distortion of the groove caused by repeated overwriting operation to improve reliability of the optical disc.
摘要:
An optical phase-change disc comprises a substrate having thereon a spiral groove or concentric grooves for guiding a focused light beam, and a layer structure including a recording layer and protective layers sandwiching therebetween the recording layer. The groove has wobble for recording ATIP (absolute time information) or ADIP (address information). The following relationship between the groove width GW, beam diameter R.sub.0 and wobble amplitude a.sub.w :0.25.ltoreq.GW/R.sub.0 .ltoreq.0.45 or 0.65.ltoreq.GW/R.sub.0 ; and0.03.ltoreq.a.sub.w /GW.ltoreq.0.08hold for preventing distortion of the groove caused by repeated overwriting operation to improve reliability of the optical disc.
摘要:
An optical phase-change disc comprises a substrate having thereon a spiral groove or concentric grooves for guiding a focused light beam, and a layer structure including a recording layer and protective layers sandwiching therebetween the recording layer. The groove has wobble for recording ATIP (absolute time information) or ADIP (address information). The following relationship between the groove width GW, beam diameter R.sub.0 and wobble amplitude a.sub.w :0.25.ltoreq.GW/R.sub.0 .ltoreq.0.45 or 0.65.ltoreq.GW/R.sub.0 ; and0.03.ltoreq.a.sub.w /GW.ltoreq.0.08hold for preventing distortion of the groove caused by repeated overwriting operation to improve reliability of the optical disc.
摘要:
An optical information recording medium for recording, retrieving and erasing mark length-modulated amorphous marks, which comprises a substrate, and a lower protective layer, a phase-change recording layer, an upper protective layer and a reflective layer having a thickness of from 40 to 300 nm and a volume resistivity of from 20 to 150 n.OMEGA..multidot.m, formed in this sequence on the substrate.
摘要:
A rewritable optical recording medium includes a substrate and a phase-change type recording layer. A portion in a crystalline state corresponds to an unrecorded or erased state, and a portion in an amorphous state correspond to a recorded state, to record EFM modulated information by forming amorphous marks by irradiating the recording layer with a recording laser beam, and the recording is carried out by irradiating a recording laser beam having a wavelength of about 780 nm through an optical system having a numerical aperture NA of 0.5 or 0.55, at 24-times velocity or 32-times velocity of the reference velocity.
摘要:
A rewritable optical recording medium including: a substrate having a guide groove formed thereon, a phase-change type recording layer, a portion in a crystalline state of the phase-change type recording layer corresponds to an unrecorded or erased state, and a portion in an amorphous state of the phase-change type recording layer corresponds to a recorded state, so that an amorphous mark corresponding to the recorded state is formed upon irradiation with a recording laser beam. The phase-change type recording layer contains Sb as a main component, and further contains Ge and/or Te, a content of Ge is from 1 atomic % to 30 atomic %, and a content of Te is from 10 atomic % to 30 atomic %, and in the phase-change type recording layer, Sb/Te is at least 4.5, and the atomic ratio of Ge to Te is from 1:3 to 1:20.
摘要:
An optical information recording medium comprising a substrate provided with periodically wobbling guide grooves with a track pitch of 1.6.+-.0.1 .mu.m, and a lower protective layer, a phase-change type recording layer, an upper protective layer and a reflective layer formed in this sequence on the substrate, for recording, retrieving and erasing amorphous marks in the guide grooves by modulation of light intensity of at least two levels by means of a focused light having a wavelength of 780.+-.30 nm applied from the side of the substrate opposite to the recording layer side so that a crystalline state with a reflectance of from 15 to 25% is an unrecorded state, and an amorphous state with a reflectance of less than 10% is a recorded state, wherein the recording layer is a thin film of an alloy of My.sub.y (Sb.sub.x Te.sub.1-x).sub.1-y where 0.ltoreq.y
摘要:
An optical information recording medium comprising a substrate provided with periodically wobbling guide grooves with a track pitch of 1.6.+-.0.1 .mu.m, and a lower protective layer, a phase-change type recording layer, an upper protective layer and a reflective layer formed in this sequence on the substrate, for recording, retrieving and erasing amorphous marks in the guide grooves by modulation of light intensity of at least two levels by means of a focused light having a wavelength of 780.+-.30 nm applied from the side of the substrate opposite to the recording layer side so that a crystalline state with a reflectance of from 15 to 25% is an unrecorded state, and an amorphous state with a reflectance of less than 10% is a recorded state, wherein the grooves have a depth of from 25 to 45 nm and a width of from 0.4 to 0.6 .mu.m.
摘要:
A rewritable optical recording medium including: a substrate having a guide groove formed thereon, a phase-change type recording layer, a portion in a crystalline state of the phase-change type recording layer corresponds to an unrecorded or erased state, and a portion in an amorphous state of the phase-change type recording layer corresponds to a recorded state, so that an amorphous mark corresponding to the recorded state is formed upon irradiation with a recording laser beam. The phase-change type recording layer contains Sb as a main component, and further contains Ge and/or Te, a content of Ge is from 1 atomic % to 30 atomic %, and a content of Te is from 10 atomic % to 30 atomic %, and in the phase-change type recording layer, Sb/Te is at least 4.5, and the atomic ratio of Ge to Te is from 1:3 to 1:20.
摘要:
The present invention provides CD-RW which makes high velocity recording at a level of at least 24-times velocity possible, rewritable DVD which makes high velocity recording at a level of at least 6-times velocity possible, and a recording method therefor, while maintaining interchangeability with conventional CD-RW standards and rewritable DVD standards.A rewritable optical recording medium comprising a substrate and a phase-change type recording layer, wherein a portion in a crystalline state corresponds to an unrecorded or erased state, and a portion in an amorphous state correspond to a recorded state, to record EFM modulated information by forming amorphous marks by irradiating the recording layer with a recording laser beam, and wherein recording is carried out by irradiating a recording laser beam having a wavelength of about 780 nm through an optical system having a numerical aperture NA of 0.5 or 0.55, at 24-times velocity or 32-times velocity of the reference velocity, where the reference velocity (1-time velocity) is a linear velocity of from 1.2 m/s to 1.4 m/s, modulation m11 of record signals is from 60% to 80%, the top value Rtop of the reflectivity of the high pattern is from 15% to 25%, and jitters are at most 35 nsec.