Abstract: A method for recording information is disclosed in which an information recording medium is irradiated with a recording energy beam power-modulated into at least a record power level and a record-ready power level lower than the record power level. When forming a mark portion of a predetermined length, the radiation energy of the energy beam is increased as compared with when forming a mark portion of a different length before or after the first pulse of an energy beam pulse train including at least a pulse for forming the mark portion. Also, only in the case where the energy beam is modulated by the power lower in power level than the record-ready power level after the last pulse of the energy beam pulse train including at least one pulse for forming a mark portion and the mark portion is followed by a space portion of a predetermined length, the particular radiation energy of low power level is reduced as compared with when the mark portion is followed by a space potion of a different length.

Abstract: An information recording medium which is composed of a substrate and a recording layer formed thereon to record information by means of the change in atomic arrangement induced by irradiation with light, said recording layer having at least one interface layer laminated at its interface. It is superior in recording-reproducing-rewriting characteristics and archival life.

Abstract: An information recording medium having a substrate, a lower superficial layer formed on the substrate and having a thickness of not more than 25 nm, and a recording layer formed on the lower superficial layer. Information is recorded on the recording layer in accordance with a change of atomic arrangement caused by irradiation of light. The information recording medium includes and an absorption control layer formed on the recording layer.

Abstract: A phase change optical disk medium includes a disklike substrate, and a recording layer formed by a laminate of a plurality of thin layers including a phase change layer. Information marks are recorded on the phase change layer by phase changes from a crystal phase to an amorphous phase and vice versa. The recording layer has tracks for recording information marks formed by groove portions and land portions respectively taking alternate concave and convex shapes. The track has an interval in range of 0.54 to 0.64 &mgr;m and the recording layer has a ratio of the optical reflectance of 0.35 or less when the phase change layer has changed to the amorphous phase in case where the optical reflectance of the recording layer is 1 when the phase change layer is in the crystal phase.

Abstract: An optical disk for recording/reproducing information have the problem of the fine irregularities on its substrate surface that causes increase of noise, under the process of forming the recording layer capable of changing physically or chemically by irradiation of laser light. The problem could deteriorate the record and reproduction characteristics and bring about a defect on a life test or on its storage ability. To solve the problem, the present invention provides the method of manufacturing an optical disk having the pits-and-lands pattern whose organic material is modified by the ultraviolet light irradiation. The transmission of the substrate is not more than 50% at one wavelength in a wavelength region from 300 to 375 nm. And, thereby the surface of an optical disk substrate is smoothed to effect the reduction of the substrate noise and the improvement of record and reproduction characteristics.

Abstract: A method for recording information is disclosed in which an information recording medium is irradiated with a recording energy beam power-modulated into at least a record power level and a record-ready power level lower than the record power level. When forming a mark portion of a predetermined length, the radiation energy of the energy beam is increased as compared with when forming a mark portion of a different length before or after the first pulse of an energy beam pulse train including at least a pulse for forming the mark portion. Also, only in the case where the energy beam is modulated by the power lower in power level than the record-ready power level after the last pulse of the energy beam pulse train including at least one pulse for forming a mark portion and the mark portion is followed by a space portion of a predetermined length, the particular radiation energy of low power level is reduced as compared with when the mark portion is followed by a space potion of a different length.

Abstract: The object is to hold the recording, reproduction and rewrite characteristics better than in the prior art. An information recording medium comprises an information recording thin film as a recording layer formed on a substrate for recording and/or reproducing information by the change in the atomic arrangement caused by the radiation of light. The medium further comprises at least one protective layer. The protective layer and the recording layer are formed in that order from the light incidence side, followed by forming at least one absorption control layer, thereby exhibiting a superior rewrite characteristic.

Abstract: An information recording medium which includes at least a recording layer, and first and second metallic layers disposed on an opposite side of an energy beam incident side of the recording layer and having different compositions, and in which the first one of the first and second metallic layers located closer to the recording layer contains Al, Ag, Au, Pt and Pd as its main components and a sum of contents of these atoms is 60% or more. Thereby recording and reproducing of information can be realized with a high reliability.

Abstract: A phase change optical disk medium includes a disklike substrate, and a recording layer formed by a laminate of a plurality of thin layers including a phase change layer. Information marks are recorded on the phase change layer by phase changes from a crystal phase to an amorphous phase and vice versa. The recording layer has tracks for recording information marks formed by groove portions and land portions respectively taking alternate concave and convex shapes. The track has an interval in range of 0.54 to 0.64 .mu.m and the recording layer has a ratio of the optical reflectance of 0.35 or less when the phase change layer has changed to the amorphous phase in case where the optical reflectance of the recording layer is 1 when the phase change layer is in the crystal phase.

Abstract: A multilayer optical information medium provided with structure in which first and second substrates respectively provided with two to four layers of planar information areas are respectively arranged outside wherein the thickness of the above-described first and second substrates is set in the range of 0.52 to 0.65 mm. The above-described planar information area consists of embossed pits provided, for example on the surface of respective substrates or on the surface of a layer formed by transparent material and a semi-reflective layer provided on the embossed pits. A planar information area arranged in the farthest position from respective substrates is provided with a reflective layer in place of the above-described semi-reflective layer. The planar information area arranged in the farthest position from respective substrates may be constituted by a recording layer and a reflective layer provided on the recording layer.

Abstract: An optical disk apparatus using an optical disk in which a layer (a reflectivity adjustment layer) in which the optical constants are changed by melting at the time of irradiation of light is provided separately from a recording layer using a phase change, and the reflectivity at a portion having a high reflectivity on the recording track is 40% or lower at the time of irradiation of strong light, and the reflectivity at the same portion is 60% or higher at the time of irradiation of weak light, wherein when the laser power is set to a power which is higher than the power at which the optical constants of the reflectivity adjustment layer are greatly changed at the time of rewriting and at which a high melting-point component is not melted, remaining of an unerased portion during rewriting due to a difference in reflectivity between the written mark portion and the other portions can be prevented and the possible number of rewritings can be increased, and hence an optical disk which has a high recording sensi

Abstract: An information recording medium comprises at least a substrate, a recording layer which is installed on the substrate via a protection layer and in which the atomic arrangement is changed without the shape thereof being changed when a recording energy beam is irradiated and the optical constants are changed, and a reflection layer reflecting the recording energy beam and by making the information recording medium comprise a material such that the mean composition of the recording layer is expressed by a general expression of A.sub.w Ge.sub.x Te.sub.y Se.sub.z (where symbols w, x, y, and z indicate atomic percent and have the predetermined values and A indicates at least one of the predetermined elements Sb, Cr, Co, In, and Ag, etc.), an information recording medium in which the recording, erasing, and reproducing characteristics are satisfactory and the stability is kept superior for a long period of time can be obtained.

Abstract: In a three-dimensional recording and reproducing apparatus having a recording medium including a plurality of recording layers stacked on a substrate and an optical system for converging a light irradiated from the substrate side on each of the plurality of recording layers to three-dimensionally record and reproduce information, the following equation is satisfied:.lambda./4.ltoreq.(1/8NB)(1/NB.sup.2 -1)NAF.sup.4 .DELTA.dwhere.lambda.: Wavelength of the light;NB: Refractivity of the substrate 3;NAF: Numerical aperture of a focus lens 8 for converging a light;.DELTA.d: Positional range in the optical axis direction in which exists a recording layer on which the light is to be converged.A light spot is focused on each layer of the multi-layer structured disc to record and reproduce highly reliable data in a high density.

Abstract: An information recording medium has a thin-film recording layer and a reflective layer that reflects a laser beam. The recording layer can be composed of an inorganic substance whose optical constant changes when exposed to a laser beam due to the change of its atomic arrangement. The recording layer can also be of an organic substance that deforms when exposed to a laser beam. The medium reflectivity, with respect to the reproduction laser beam exposure from the substrate side, is at least 65 percent on either of the recorded and unrecorded marks, and not more than 45 percent from the other of the recorded and unrecorded marks. In addition, the reflective-layer reflectivity, with respect to the reproduction laser beam, is at least 85 percent. The information recording medium additionally features excellent recording, erasing, and reproduction characteristics, with low recording power and high recording sensitivity during recording, and can even be read by a CD drive or the like.

Abstract: In a three-dimensional recording and reproducing apparatus having a recording medium including a plurality of recording layers stacked on a substrate and an optical system for converging a light irradiated from the substrate side on each of the plurality of recording layers to three-dimensionally record and reproduce information, the following equation is satisfied:.lambda./4.ltoreq.(1/8/NB)(1 /NB.sup.2 -1)NAF.sup.4 .DELTA.dwhere.lambda.: Wavelength of the light;NB: Refractivity of the substrate;NAF: Numerical aperture of a focus lens for converging a light;.DELTA.d: Positional range in the optical axis direction in which exists a recording layer on which the light is to be converged.A light spot is focused on each layer of the multi-layer structured disc to record and reproduce highly reliable data in a high density.

Abstract: An information recording medium which is superior in record/read-out characteristics, high in sensitivity and good in stability can be provided at a low cost by using, as an information-recording medium in which recording is carried out due to change in atomic arrangement upon irradiation with a laser beam, an information-recording medium comprising substrates 1, 1' , recording layers 2, 2' changing in atomic arrangement upon irradiation with a recording energy beam, and reflective layers which are provided contiguous to the recording layers and the recording layer has an average composition represented by A.sub.w D.sub.x Sb.sub.y Se.sub.z (wherein w, x, y and z are in the ranges of 0.ltoreq.w.ltoreq.30, 3.ltoreq.x.ltoreq.57, 3.ltoreq.y.ltoreq.57 and 40.ltoreq.z.ltoreq.90 in atomic percent, D represents at least one element of Sn, In, Ge, Pb, Si, Bi, Ga, Au, Ag and Cu and A represents an element other than Sb, Se, the elements represented by D and rare gases).

Abstract: Disclosed herein is an information recording medium which is composed of a substrate, underlayer, and recording film and is capable of recording information by means of depressions or pits which are formed on the recording film upon irradiation with a recording energy beam, said information recording medium being characterized in that the recording film is provided with a supporting layer on at least one side of the recording film, said supporting layer having a melting point which is lower than that of the recording film, or on that side of the recording film which is adjacent to the substrate, said supporting layer having a melting point which is higher than that of the recording film. Owing to these features, the information recording medium gives recording pits having a smaller rim inner diameter, so that it achieves a high recording power margin for high-density recording.

Abstract: A method of recording information by changing a recording medium through irradiation with an energy beam such as a light beam, electron beam or the like. A single pulse or a plurality of pulses are employed for forming recorded dots. The pulse has a pulse width shorter than a time required for the center of energy beam spot to move from one to other end of the dot upon recording thereof. By virtue of the possibility of reversible change even in a recording film susceptible to high rate speed of change, the rate of information transfer can be increased. Over-write recording can also be accomplished with the single laser beam. An increased amount of information can be handled in the recording and reproduction.

Abstract: Disclosed are optical recording media having interposed an organic compound between a metal stamper and a transparent substrate and forming a replica onto which a signal surface formed on the metal stamper is transferrable to the transparent substrate.

Abstract: By recording, reproducing and erasing information by using a recording thin film of the present invention, the information can be recorded, reproduced and erased by a single beam spot and new information can be rapidly rewritten while recorded information is erased. The irradiation beam is not limited to a light beam but it may be other energy beam such as electron beam or ion beam. The record medium is not limited to a disk but it may be tape or card and is applicable to a recording thin film other than the described thin film and to other methods.By using the described recording thin film, a manufacturing process is simple and reproducible, the recording/reproducing characteristic is high and the information can be stably stored for an extended time period. The record also may be rewritten a number of times.