Abstract: An apparatus includes: a generation unit that generates a PWM wave based on a sound signal; and a processing unit that converts the PWM wave to a square wave. The processing unit includes: a first counter that determines a pulse width of the PWM wave; a comparison unit that compares a first difference value, obtained by subtracting the pulse width in a second cycle being a cycle immediately preceding a first cycle from the pulse width in the first cycle, and a second difference value obtained by subtracting the pulse width in a cycle immediately preceding the second cycle from the pulse width in the second cycle; and an output unit that outputs the square wave while switching a state thereof in a case where a sign of the first difference value changes from that of the second difference value.

Abstract: An apparatus includes: a generation unit that generates a PWM wave based on a sound signal; and a processing unit that converts the PWM wave to a square wave. The processing unit includes: a first counter that determines a pulse width of the PWM wave; a comparison unit that compares a first difference value, obtained by subtracting the pulse width in a second cycle being a cycle immediately preceding a first cycle from the pulse width in the first cycle, and a second difference value obtained by subtracting the pulse width in a cycle immediately preceding the second cycle from the pulse width in the second cycle; and an output unit that outputs the square wave while switching a state thereof in a case where a sign of the first difference value changes from that of the second difference value.

Abstract: The optical information recording medium of the present invention includes a plurality of information layers provided on a substrate and an optical separating layer provided between information layer adjacent to each other, and information is recorded or reproduced by irradiation of a laser beam. When an information layer that is provided closest to a laser beam incident side of the plurality of information layers is taken as a first information layer and an optical separating layer provided in contact with the first information layer is taken as a first optical separating layer, then the first information layer comprises a recording layer, a transmittance adjusting layer that adjusts a transmittance of the first information layer, and a low refractive index layer provided between the transmittance adjusting layer and the first optical separating layer.

Abstract: An optical information recording medium includes one or more information layers including a recording layer for recording/reproducing an information signal by irradiation with a laser light, and a seperating layer or a protective substate on which a first information layer of the information layer on the irradiation face side is formed. The seperating layer or the protective substrate having a guide groove spirally or concentrically formed on the surface, and the respective inclined planes on the inner perimeter side and the outer perimeter side of the guide groove having inclined angles ? and ? with respect to the bottom face of the guide groove. The guide groove has one or more dissymmetric regions in the radius direction where the inclined angles ? and ? are different. The information layer has roughly agreeing thicknesses in the inclined face portion on the inner and outer perimeter sides in the dissymmetric region.

Abstract: The present invention provides an optical information recording medium of excellent signal quality in high density recording onto a semitransparent information layer, its manufacturing method and a manufacturing apparatus. The optical information recording medium of the present invention includes at least a semitransparent information layer disposed between a circular transparent substrate and a protective substrate, in which the information layer has spiral grooves for guiding a light beam, and also includes a recording film capable of recording/reproducing information thereon/therefrom by changing at least in two states detectable optically by irradiation of the light beam from the transparent substrate side, and the difference in film thickness of slope portions of the inner circumferential side and outer circumferential side of the groove is within ±10% in the entire region for recording/reproducing information.

Abstract: A method for appropriately performing initialization of an optical information recording medium is provided, in which an initialization process is prevented from stopping so that yield from manufacturing the optical information recording medium is improved. In the initialization of an information layer with a burst cutting area (hereinafter referred to as “BCA”), at least one of the initialization conditions including a laser power, a linear speed, and a focal point of the laser beam for the information layer is changed between the BCA region and a data area that is an area for recording and reproducing information. In the initialization of an information layer without the BCA, at least one of the initialization conditions including a laser power, a linear speed, a focal point of the laser beam for the information layer and a feed pitch is changed between the area corresponding to the BCA and the area corresponding to the data area.

Abstract: A disk with an Ag reflective layer, a recording layer including elements Sb and Te, and a dielectric layer including S provided between the reflective layer and the recording layer has the problems of corrosion of the Ag reflective layer, decline of the signal quality due to insufficient heat releasing ability, and exfoliation between the layers. (1) A phase-change optical disk includes, on a transparent substrate, a recording layer in which an optically detectable reversible change between an amorphous phase and a crystalline phase can be caused by irradiation with an energy beam, a reflective layer, and a dielectric layer arranged between the recording layer and the reflective layer, wherein the main component of the dielectric layer is an oxide or a nitrooxide of Ta.

Abstract: An optical information recording medium on which information can be recorded and reproduced by using a laser beam is provided. The medium includes a substrate with a guide groove and a multilayered metal film including at least a first metal layer, a barrier layer and a second metal layer that are deposited on the substrate in this order, or a single layer metal film including at least a metal layer and a recording layer are deposited on the substrate in this order. The second metal layer and the metal layer of the single layer metal film are a material containing Al and a metal element (an additive) as main components.

Abstract: When initializing first and second information layers on a phase-change optical disk of the one-side multilayered configuration, a mistake occurs depending on thin film configuration of first and second information layers. The phase-change optical disk having a plurality of information layers having at least a recording layer of generating optically detectable reversible change between an amorphous phase and a crystalline phase on a transparent substrate by irradiation of an energy beam and having an optical separation layer formed between the information layers, wherein initialization start positions of crystallizing said plurality of information layers vary by irradiating a laser beam thereon.

Abstract: In an optical information recording medium having at least two information layer, guide grooves for tracking or sample pits or information pits corresponding to information signals are formed on a surface of a first substrate. A first information layer formed by a thin film for reflecting a portion of a light beam made incident on the first substrate and permitting penetration of a portion of the light beam is formed on a surface of the first substrate. Guide grooves for tracking or information pits corresponding to information signals are formed on a surface of a second substrate. A second information layer having a reflectance higher than that of the first information layer is formed on a surface of the second substrate. Between the first information layer and the second information layer, there is formed a transparent separation layer for positioning the first information layer and the second information layer to be spaced a predetermined distance apart from each other.

Abstract: In an optical information recording medium having at least two information layer, guide grooves for tracking or sample pits or information pits corresponding to information signals are formed on a surface of a first substrate. A first information layer formed by a thin film for reflecting a portion of a light beam made incident on the first substrate and permitting penetration of a portion of the light beam is formed on a surface of the first substrate. Guide grooves for tracking or information pits corresponding to information signals are formed on a surface of a second substrate. A second information layer having a reflectance higher than that of the first information layer is formed on a surface of the second substrate. Between the first information layer and the second information layer, there is formed a transparent separation layer for positioning the first information layer and the second information layer to be spaced a predetermined distance apart from each other.

Abstract: An optical information recording medium is provided with a plurality of information layers (2, 3), each of which has a sector structure in which a data area (8, 12) is divided in the circumferential direction by a sector address (9, 13). The positions of the sector addresses (9, 13) of the respective information layers (2, 3) coincide in the circumferential direction. This can prevent errors during reproduction caused by the effect of other information layers and stabilize recording characteristics, resulting in an increased recording capacity of a rewritable recording medium having a plurality of information layers with a sector structure.

Abstract: An optical information recording medium with excellent surface flatness and little inter-mark interference during recording, as well as a method for manufacturing this medium are provided. An optical information recording medium 10 capable of reproducing information using laser light having a reflective layer 2 and a recording layer 5, in that order, on a substrate 1, and the reflective layer 2 being an alloy containing aluminum and nickel.

Abstract: An optical information recording medium is provided which has favorable signal quality even in high density recording using a translucent information layer. The optical information recording medium includes one or more information layers including a recording layer for recording/reproducing an information signal by irradiation with a laser light, and a separating layer or a protective substrate on which a first information layer of the information layer on the irradiation face side is formed, the separating layer or the protective substrate having a guide groove spirally or concentrically formed on the surface, and the respective inclined planes on the inner perimeter side and the outer perimeter side of the guide groove having inclined angles ? and ? with respect to the bottom face of the guide groove. The guide groove has one or more dissymmetric regions in the radius direction where the inclined angles ? and ? are different.

Abstract: In an optical information recording medium having at least two information layer, guide grooves for tracking or sample pits or information pits corresponding to information signals are formed on a surface of a first substrate. A first information layer formed by a thin film for reflecting a portion of a light beam made incident on the first substrate and permitting penetration of a portion of the light beam is formed on a surface of the first substrate. Guide grooves for tracking or information pits corresponding to information signals are formed on a surface of a second substrate. A second information layer having a reflectance higher than that of the first information layer is formed on a surface of the second substrate. Between the first information layer and the second information layer, there is formed a transparent separation layer for positioning the first information layer and the second information layer to be spaced a predetermined distance apart from each other.

Abstract: The optical information recording medium of the present invention includes a plurality of information layers provided on a substrate and an optical separating layer provided between information layer adjacent to each other, and information is recorded or reproduced by irradiation of a laser beam. When an information layer that is provided closest to a laser beam incident side of the plurality of information layers is taken as a first information layer and an optical separating layer provided in contact with the first information layer is taken as a first optical separating layer, then the first information layer comprises a recording layer, a transmittance adjusting layer that adjusts a transmittance of the first information layer, and a low refractive index layer provided between the transmittance adjusting layer and the first optical separating layer.

Abstract: The present invention provides an optical information medium having excellent weather resistance and repeating characteristics. The optical information medium has a barrier layer between a protective layer and a recording layer. The barrier layer includes GeN or GeON, and at least one element selected from the group consisting of Al, B, Ba, Bi, C, Ca, Ce, Cr, Dy, Eu, Ga, H, In, K, La, Mn, N, Nb, Ni, Pb, Pd, S, Si, Sb, Sn, Ta, Te, Ti, V, W, Yb, Zn and Zr.

Abstract: In an optical information recording medium having at least two information layer, guide grooves for tracking or sample pits or information pits corresponding to information signals are formed on a surface of a first substrate. A first information layer formed by a thin film for reflecting a portion of a light beam made incident on the first substrate and permitting penetration of a portion of the light beam is formed on a surface of the first substrate. Guide grooves for tracking or information pits corresponding to information signals are formed on a surface of a second substrate. A second information layer having a reflectance higher than that of the first information layer is formed on a surface of the second substrate. Between the first information layer and the second information layer, there is formed a transparent separation layer for positioning the first information layer and the second information layer to be spaced a predetermined distance apart from each other.

Abstract: In a multilayered recording medium, when a titanium oxide layer is formed using a sheet-type sputtering device, a transmittance significantly varies due to variations in thickness of the titanium oxide layer. Therefore, according to the present invention, in the multilayered recording medium having the titanium oxide layer, a second dielectric layer composed of titanium oxide, or mainly composed of the same, is formed on a first dielectric layer composed of niobium oxide or silicon dioxide, or mainly composed of the same. Further, when the sheet-type sputtering device is used, at least one chamber for promoting removal of water and oxygen from a substrate is provided between a load lock chamber and a chamber for forming a transmittance adjustment layer.

Abstract: An optical information recording medium of the invention has at least two information layers. A first information layer (100) disposed at the front side (viewed from a laser incident side) includes at least a reflection layer (3), a recording layer (6) disposed at the laser incident side with respect to the reflection layer (3), for generating a reversible change between an amorphous phase and a crystalline phase that can be detected optically by applying a laser beam, and a dielectric layer (50) disposed between the reflection layer (3) and the recording layer (6). The dielectric layer (50) contains at least Zr, Si and Cr, a ratio of Zr, Si and Cr of the dielectric layer (50) at the reflection layer side is expressed as Zr:Si:Cr=p:q:r (p+q+r=100), a ratio of Zr, Si and Cr of the dielectric layer (50) in the vicinity of the interface at the recording layer side is expressed as Zr:Si:Cr=s:t:u (s+t+u=100), and r<u or t<q.