Abstract: To provide an information recording medium which permits high density recording/reproduction, which has good thermal stability, and which, due to the use of an interface layer with a high sputter rate, has good recording/reproduction characteristics and is excellent for mass production. An information recording medium wherein the thickness of an interface layer 3 is 0.25 or more but 0.67 or less of the total thickness of a first protective layer 2 and the interface layer 3, and the interface layer 3 contains at least tantalum (Ta) and oxygen (O). The medium is excellent for mass production and has good recording/reproduction characteristics for high density recording/reproduction.

Abstract: A high-density information recording medium free from lowering the reflectance by over-write of a large number of times and exfoliation defect in a structure for suppressing cross-erase. This medium includes, over a substrate having a groove shape, a recording layer, and three-layered thin films of a first interference layer, a second interference layer and an interface layer having mutually different compositions and disposed on a laser beam incidence side of the recording layer in order named from the laser beam incidence side. The first interference layer has a smaller refractive index and a larger thermal conductivity than the second interference layer, the interface layer is interposed between the second interference layer and the recording layer, and a distance between the first interference layer and the recording layer is greater than at least a groove depth.

Abstract: A multi-time rewritable information recording medium conducting writing by the change of arrangement of atoms under the irradiation of light, comprising, from the light-incident side, a substrate of a thickness of 0.7 mm or less, a lower protective layer of a thickness of 20 nm to 60 nm, a recording film, an upper protective layer, and a reflective layer, wherein the interval between tracks is 0.62 &mgr;m or less. The medium can also possess favorable writing/reading characteristics at high density writing/reading, have large processing margin, use a manufacturing apparatus at a reduced cost, cut material cost, and realize mass productivity with less stresses.

Abstract: This invention relates to an information-recording medium that is used for recording information through radiation of energy beam. The information recording medium has a groove-shaped information recording track and is provided with a recording layer, one or more kinds of heat sink control layers and heat sink layers. A sum of film thickness of the more than one kind of recording layer is equal to or less than a step between information recording tracks, and a sum of film thickness of one or more kinds of heat sink control layers is more than a groove depth of the information recording track. With this configuration, no cross-erase is produced even if the information-recording medium is applied for a high density recording with the track pitch being 70% or less.

Abstract: In an information recording medium, a first protective layer, a recording film, a second protective layer and a reflective layer are provided on a substrate sequentially from a side where light is irradiated, the first protective layer having a film thickness of 2 nm to 25 nm. 95 atomic % or more of a material of the first protective layer is SiO2—In2O3—SnO2—ZnS, and a ZnS amount in the first protective layer is in the range of 4 mol % to 33 mol %.

Abstract: A sheet used as a spacer layer is made of photo-curing organic material and thermoplastic organic material, a stamper is pressed on the sheet, and light irradiating is performed after the stamper is stripped.

Abstract: This invention relates to an information-recording medium that is used for recording information through radiation of energy beam. The information recording medium has a groove-shaped information recording track and is provided with a recording layer, one or more kinds of heat sink control layers and heat sink layers. A sum of film thickness of the more than one kind of recording layer is equal to or less than a step between information recording tracks, and a sum of film thickness of one or more kinds of heat sink control layers is more than a groove depth of the information recording track. With this configuration, no cross-erase is produced even if the information-recording medium is applied for a high density recording with the track pitch being 70% or less.

Abstract: Problem to be solved is that when an information recording medium is repeatedly subjected to recording of information several hundreds times, the atoms in a protective layer are diffused and dissolved into a recording layer to lower a reflectivity greatly and make the medium unendurable to many times of overwriting. This problem can be solved by a medium constituted of interference layer 10, interface layer 12, phase-change type recording layer 14, protective layer 13 having a tin content of from 23.3 atomic % to 32.3 atomic %, and a heat sink layer 8 successively formed on substrate 1, as seen from a light-incidence side. By use of this medium, the dissolution of atoms can be prevented, and overwriting for many times can be achieved.

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: To provide an information recording medium which permits high density recording/reproduction, which has good thermal stability, and which, due to the use of an interface layer with a high sputter rate, has good recording/reproduction characteristics and is excellent for mass production. An information recording medium wherein the thickness of an interface layer 3 is 0.25 or more but 0.67 or less of the total thickness of a first protective layer 2 and the interface layer 3, and the interface layer 3 contains at least tantalum (Ta) and oxygen (O). The medium is excellent for mass production and has good recording/reproduction characteristics for high density recording/reproduction.

Abstract: A sheet used as a spacer layer is made of photo-curing organic material and thermoplastic organic material, a stamper is pressed on the sheet, and light irradiating is performed after the stamper is stripped.

Abstract: An information recording medium having a substrate, a recording layer on which information is recorded in accordance with a change of atomic arrangement caused by irradiation of light, a first reflective layer, and a second reflective layer. The second reflective layer is formed on the first reflective layer. The first reflective layer includes an Al alloy as a main component and the second reflective layer includes an Ag alloy as a main component.

Abstract: A multi-time rewritable information recording medium conducting writing by the change of arrangement of atoms under the irradiation of light, comprising, from the light-incident side, a substrate of a thickness of 0.7 mm or less, a lower protective layer of a thickness of 20 nm to 60 nm, a recording film, an upper protective layer, and a reflective layer, wherein the interval between tracks is 0.62 &mgr;m or less. The medium can also possess favorable writing/reading characteristics at high density writing/reading, have large processing margin, use a manufacturing apparatus at a reduced cost, cut material cost, and realize mass productivity with less stresses.

Abstract: A method of writing a visible figure in an optical disk, including the steps of providing an application program; providing an optical disk having a recording region/film made of a phase-changing material in which a first visible figure is written, the application program storing data to write a second visible figure in the optical disk; reading data for writing the second visible figure; developing figure data which has been read into writing coordinates; converting the writing coordinates into disk coordinates; generating a laser driving pattern for each track of the recording region/film to write the second visible figure based on the developed figure data on the disk coordinates; and driving the laser based on the laser driving pattern, thereby irradiating the optical disk to write the second visible figure in the recording region/film to change the first visible figure into the second visible figure.

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: 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: To write visible figures 710, 720 by gather of element regions in which the average reflectivity per area 0.01 mm×0.01 mm changes more than 5% from the background region at any of visible wavelengths.

Abstract: An optical disk for recording/reproducing information tends to have fine irregularities on its substrate surface that cause an increase in noise, which irregularities are formed during the process of forming the recording layer, which is capable of changing physically or chemically in response to irradiation of laser light. This problem can deteriorate the recording and reproduction characteristics and bring about a defect on a life test or on the storage ability on the disk. To solve this problem, a method of manufacturing an optical disk having a pits-and-lands pattern employs an organic material which is modified by 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. As a result of the ultraviolet ray irradiation, the surface of an optical disk substrate is smoothed so as to effect a reduction of the substrate noise and an improvement of the recording and reproduction characteristics.

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 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.