Abstract: An optical recording medium is provided. The optical recording medium includes a multilayer including an N (N?5) number of interfaces capable of reflecting incident light.

Abstract: An optical recording medium is provided. The optical recording medium includes a multilayer including an N (N?5) number of interfaces capable of reflecting incident light.

Abstract: An optical recording medium includes a substrate having features that define track regions, an optical recording layer disposed on the substrate, and a light-transmitting layer disposed on the optical recording layer. The optical recording layer has a composition of (Sb2Se3)wTexOyPdz, where w, x, y, and z each represent a molar percent and satisfy 10 (mol %)?w?60 (mol %), 0 (mol %)<x?60 (mol %), 30 (mol %)?y?60 (mol %), 10 (mol %)?z?30 (mol %), and w+x+y+z=100.

Abstract: An optical recording medium includes a substrate having features that define track regions, an optical recording layer disposed on the substrate, and a light-transmitting layer disposed on the optical recording layer. The optical recording layer has a composition of (Sb2Se3)wTexOyPdz, where w, x, y, and z each represent a molar percent and satisfy 10 (mol %)?w?60 (mol %), 0 (mol %)<x?60 (mol %), 30 (mol %)?y?60 (mol %), 10 (mol %)?z?30 (mol %), and w+x+y+z=100.

Abstract: An optical recording medium using Sn as the recording material to improve the jitter is provided, in which on the surface of a disc substrate 11 where a concave and convex shape dividing a track area is formed, are formed on the surface of the concave and convex shape a first protective layer 31 for protecting at least an optical recording layer 31, an optical recording layer 12 using a chemical compound at least composed of tin (Sn), nitrogen (N) and oxygen (O), formed on the first protective layer, a second protective layer 32 for protecting this optical recording layer, formed on this optical recording layer, and a light-transmittable layer 13 formed on the second protective layer; with this structure, the optical recording layer 12 under high temperature and high humidity can be stabilized by means of the first and second protective layers 31 and 32.

Abstract: An optical recording medium using Sn as the recording material to improve the jitter is provided, in which on the surface of a disc substrate 11 where a concave and convex shape dividing a track area is formed, are formed on the surface of the concave and convex shape a first protective layer 31 for protecting at least an optical recording layer 31, an optical recording layer 12 using a chemical compound at least composed of tin (Sn), nitrogen (N) and oxygen (O), formed on the first protective layer, a second protective layer 32 for protecting this optical recording layer, formed on this optical recording layer, and a light-transmittable layer 13 formed on the second protective layer; with this structure, the optical recording layer 12 under high temperature and high humidity can be stabilized by means of the first and second protective layers 31 and 32.

Abstract: An optical recording medium using Sn as the recording material to improve the jitter is provided, in which on the surface of a disc substrate 11 where a concave and convex shape dividing a track area is formed, are formed on the surface of the concave and convex shape a first protective layer 31 for protecting at least an optical recording layer 31, an optical recording layer 12 using a chemical compound at least composed of tin (Sn), nitrogen (N) and oxygen (O), formed on the first protective layer, a second protective layer 32 for protecting this optical recording layer, formed on this optical recording layer, and a light-transmittable layer 13 formed on the second protective layer; with this structure, the optical recording layer 12 under high temperature and high humidity can be stabilized by means of the first and second protective layers 31 and 32.

Abstract: An optical recording medium has a transparent substrate with a recorded pattern formed thereon and a saturable absorption dye containing layer disposed on the recorded pattern and containing at least a saturable absorption dye. The saturable absorption dye has a molecular extinction coefficient .epsilon. of 10.sup.4 or greater at the wavelength of reproducing light, and a relaxation time .tau. in the range of 1 ns.ltoreq..tau..ltoreq. 100 ns. A reflecting layer having a reflectivity of 70% or higher on an air boundary thereof may be disposed on the saturable absorption dye containing layer. The saturable absorption dye containing layer may have such a thickness that substantially minimizes the intensity of reflected light due to interference with respect to the intensity of the reproducing light. The saturable absorption dye may comprise a naphthalocyanine-based dye.

Abstract: An optical disk reproducing apparatus for optical disks which are have a material layer whose reflectivity is lowered when a temperature of this material exceeds a predetermined temperature, is fabricated on a transparent substrate. A plurality of phase pits have been formed in this substrate corresponding to an information signal. The optical disk reproducing apparatus comprises: an optical pickup for reading the information signal by irradiating on a recording plane of the optical disk, a first optical spot for reproducing the information signal, and also second and third optical spots each having lower light intensity than that of the first optical spot. The second and third optical spots located at positions where there is no adverse influence caused by a thermal history of the first optical spot.

Abstract: An optical recording medium has a multi-layer film including a reproducing layer and a recording holding layer magnetically coupled to each other as a recording film. While a readout light is radiated to the optical recording medium for erasing the recording holding layer and the reproducing layer or transcribing signals magnetically recorded in the recording holding layer to the reproducing layer, the signals are converted by photomagnetic effects into optical signals which are read, or an optical recording medium having phase pits changed in reflectance with temperature. While a readout light beam is radiated to the optical recording medium and the reflectance is changed partially within a scanning spot of the readout light beam, the phase pits are read. The minimum pit interval of the recording signals along the scanning direction of the readout light beam is selected to be not more than .lambda./2NA, where .lambda.

Abstract: A zinc or zinc-alloy plated steel sheet having an improved weldability and plating properties, as well as a method for making the same is provided. Even when the substrate steel sheet is the one which is difficult to deposit a zinc or zinc-alloy layer by conventional methods, such as an extra low carbon steel sheet, the present invention enables a reliable production of a galvanized steel sheet suffering from no plating failure of insufficient adhesion as well as a reliable production of a galvanized steel sheet suffering from no plating failure or streaking of the alloyed layer. The zinc or zinc-alloy plated steel sheet having improved weldability comprises an extra low carbon steel sheet, an iron-carbon plated layer or a carbon-rich layer generated by diffusion of the iron-carbon plated layer on at least one major surface of the extra low carbon steel sheet, and a zinc or zinc-alloy plated layer on the iron-carbon plated layer or the carbon-rich layer.

Abstract: A method for reproducing a magneto-optical recording medium the recording pits of which are erased or relieved with rise in temperature of the recording medium caused by radiation of a readout light beam or an optical recording medium the reflectance of which is changed with rise in temperature of the recording medium caused by radiation of the readout light beam, in which changes in the size of an effective reproducing region due to the temperature of the recording medium may be inhibited. To this end, when the magneto-optical disc 11, for example, is rotated at a constant angular velocity, a detecting unit 17 is provided for detecting the radial position of the magneto-optical disc 11 and the laser power as well as the external magnetic field is controlled depending on an output of the detecting unit 17 for controlling the size of an effective reproducing region to be constant without regard to the linear velocity at each reproducing position.

Abstract: An optical recording medium has a multi-layer film including a reproducing layer and a recording holding layer, in which, while a readout light is radiated to the optical recording medium for transcribing signals magnetically recorded in the recording holding layer to the reproducing layer, the signals are converted by photomagnetic effects into optical signals which are read. Alternately, an optical recording medium has phase pits formed thereon in accordance with signals and changed in reflectance with temperature, in which, while a readout light beam is radiated to the optical recording medium and the reflectance is changed partially within a scanning spot the readout light beam, the phase pits are read. The track pitch p of pits RP of recording signals in a direction at right angles to the scanning direction of the laser light is set to not more than one-half the spot diameter of the laser light to raise the track density to improve the recording capacity of the recording medium.

Abstract: To increase the track density, that is, to improve the recording density of the optical disk of ultra-high resolving power reproduction type, grooves 4 are formed in a transparent substrate 2; phase pits 1 are formed on groove bottom portions 5 and land portions 6 of the grooves; and further a material layer 3 is laminated. A polycarbonate substrate is used as the transparent substrate 2. The material layer 3 is formed of such a material that the state is partially changed due to heat of the reading light in the optical spot of the reading light but returned to the original state after the reading light has passed, and in addition the reflection factor of the material is changeable according to the state change. The material layer 3 is a ternary compound of Ge.sub.2 Sb.sub.2 Te.sub.3. The thermal conductivity of the transparent substrate 2 is smaller than that of the material layer 3.

Abstract: A method for reproducing a magneto-optical recording medium the recording pits of which are erased or relieved with rise in temperature of the recording medium caused by radiation of a readout beam, or an optical recording medium the reflectance of which is changed with rise in temperature of the recording medium caused by radiation of the readout beam, in which, when the line recording density of the recording medium is changed, the size of the effective reproducing region is controlled to an optimum value conforming to the line recording density to assure a stable reproducing state.

Abstract: A method for reproducing a magneto-optical recording medium the recording pits of which are erased or relieved with rise in temperature of the recording medium caused by radiation of a readout beam, or an optical recording medium the reflectance of which is changed with rise in temperature of the recording medium caused by radiation of the readout beam, in which changes in the size of an effective reproducing region due to the temperature of the magneto-optical or optical recording medium may be inhibited. To this end, a temperature sensor 20 for sensing the temperature of the magneto-optical disc 11, for example, is provided and the laser power or the external magnetic field is controlled depending on the detected temperature by the temperature sensor 20 to maintain a constant size of the effective reproducing region at all times.

Abstract: A zinc or zinc-alloy plated steel sheet having an improved weldability and plating properties, as well as a method for making the same is provided. Even when the substrate steel sheet is the one which is difficult to deposit a zinc or zinc-alloy layer by conventional methods, such as an extra low carbon steel sheet, the present invention enable a reliable production of a galvanized steel sheet suffering from no plating failure or insufficient adhesion as well as a reliable production of a galvannealed steel sheet suffering from no plating failure or streaking of the alloyed layer.The zinc or zinc-alloy plated steel sheet having improved weldability comprises an extra low carbon steel sheet, an iron-carbon plated layer or a carbon-rich layer generated by diffusion of the iron-carbon plated layer on at least one major surface of the extra low carbon steel sheet, and a zinc or zinc-alloy plated layer on the iron-carbon plated layer or the carbon-rich layer.

Abstract: An optical disk having a greatly improved recording density. The disk has a transparent substrate provided with phase pits. A layer of a phase changeable material is formed on the substrate. This phase changeable material is a chalcogen or chalcogenide such as Sb.sub.2 Se.sub.3 or Sb.sub.2 Te.sub.3. When reading light is directed onto the disk, a part of the layer of the phase changeable material is melted within the spot of the reading light beam, and the reflectivity changes and a phase pit is read through the melted part. After the reading, the melted portion recrystallizes.

Abstract: A molded body formed of a silicon nitride-based ceramic containing Si and N and optionally O, C and/or a metal. The ceramic is formed from a polysilazane. A molded body may be a composite body which is composed of a matrix of the ceramic and a reinforcing material such as powder or fiber embedded within the matrix or which is composed of ceramic powder bound with a binder formed of the silicon nitride-based ceramic.