Abstract: Data is recorded in a phase-change optical storage medium having data layers. A first recording pulse sequence is generated for recording to a first data layer located most remote from a beam-incident surface. The first sequence has a recording pulse carrying an erasing power and a recording power rising from the erasing power, and a cooling pulse carrying a bottom power lower than the erasing power. A second recording pulse sequence is generated for recording to a second data layer. The second sequence has recording pulse carrying an erasing power and a recording power rising from the erasing power, a cooling puse carrying a bottom power lower than the erasing power, and an erasing top pulse carrying an erasing top power higher than the erasing power.

Abstract: A phase-change optical storage medium has a substrate and a recording layer having a plurality of tracks for storing information. A material of which the recording layer is made has been initialized in a crystalline state in which an amplitude of a tracking-detection signal is smaller than a saturation value of the amplitude, the tracking-detection signal being obtained by receiving a reflected beam from the recording layer when the recording layer is irradiated with a laser beam in an off-track state while the optical storage medium is being rotated.

Abstract: A phase-change optical storage medium has a substrate, and a recording layer, to be recorded on which is at least one recorded mark representing information to be recorded by irradiating a recording light beam onto the recording layer in accordance with a recording pulse pattern of recording pulses rising from an erasing power and formed between a recording power larger than the erasing power and a bottom power smaller than the erasing power and of erasing pulses rising from the bottom power to the erasing power. The expressions (1) and (2): 1.00<(R1/R0)<1.15 . . . (1), 1.05<(R9/R0)<1.20 . . .

Abstract: Information to be recorded is recorded in a recording layer of a phase-change optical storage medium. The information to be recorded is modulated to generate modulated data. Desired mark-length data is generated based on the modulated data. Generated further based on the mark-length data is a recording pulse pattern of recording pulses rising from an erasing power and formed between a recording power larger than the erasing power and a bottom power smaller than the erasing power and of erasing pulses rising from the bottom power to the erasing power. A recording light beam is then irradiated onto the recording layer in accordance with the recording pulse pattern to record at least one recorded mark representing the information to be recorded. Used in recording is an optimum erasing power, as the erasing power, the optimum erasing power satisfying an expression (1): 1.000<(R1/R0)<1.030 . . .

Abstract: An optical disk consists of a first laminated layer structure and a second laminated layer structure. The first structure has a first transparent substrate having a first surface and a second surface on both sides thereof, provided on the first surface being a light-incident plane via which a light beam is to be incident in recording or reproduction, formed alternately on the second surface being a plurality of first lands and first grooves, and a first organic-dye recording layer formed on the second surface to cover the first lands and grooves. The second structure has a second substrate, alternately formed on which are a plurality of second lands and second grooves, a reflective film formed on the second transparent substrate to cover the second lands and grooves, and a second organic-dye recording layer formed on the reflective film to face the second transparent substrate.

Abstract: Data is recorded in an optical storage medium with a beam having a wavelength in a 650-nm band. The medium has a substrate, a first laminated layer structure formed on the substrate and having at least a first reflective film and a first recording film, and a second laminated layer structure formed over the first structure and having at least a second reflective film and a second recording film. The data is recorded in at least one of specific sections of the first recording film, with a beam having a wavelength in a 650-nm band and a beam spot having a specific area. The first structure satisfies requirements Tc?Tr?60% and 9%?Rr?Rc?15% wherein Tc and Rc are a transmissivity and a reflectivity, respectively, of the first structure when the first recording film has no data recorded therein after initialized, and Tr and Rr are a transmissivity and a reflectivity, respectively, of the first structure when the first recording film has the data recorded therein.

Abstract: Data is recorded in a phase-change optical storage medium having a beam-incident surface and a plurality of data layers provided over the surface, each data layer having at least a recording film. Data to be recorded is modulated to generate modulated data. Desired mark-length data is generated based on the modulated data. A recording beam is emitted onto each data layer based on the mark-length data, to form a recorded mark carrying the data to be recorded in each data layer. A first recording pulse sequence is generated when a recorded mark is formed in a first data layer located most remote from the beam-incident surface among the data layers. The first sequence has at least a first recording pulse carrying a first erasing power and a first recording power rising from the first erasing power, and a first cooling pulse carrying a first bottom power lower than the first erasing power. A recording beam is emitted onto the first data layer in accordance with the first sequence.

Abstract: A phase-change optical storage medium has a substrate and a recording layer having a plurality of tracks for storing information. A material of which the recording layer is made has been initialized in a crystalline state in which an amplitude of a tracking-detection signal is smaller than a saturation value of the amplitude, the tracking-detection signal being obtained by receiving a reflected beam from the recording layer when the recording layer is irradiated with a laser beam in an off-track state while the optical storage medium is being rotated.

Abstract: A phase-change optical storage medium has a substrate, and a recording layer, to be recorded on which is at least one recorded mark representing information to be recorded by irradiating a recording light beam onto the recording layer in accordance with a recording pulse pattern of recording pulses rising from an erasing power and formed between a recording power larger than the erasing power and a bottom power smaller than the erasing power and of erasing pulses rising from the bottom power to the erasing power. The expressions (1) and (2): 1.00<(R1/R0)<1.15 . . . (1), 1.05<(R9/R0)<1.20 . . .

Abstract: Information to be recorded is recorded in a recording layer of a phase-change optical storage medium. The information to be recorded is modulated to generate modulated data. Desired mark-length data is generated based on the modulated data. Generated further based on the mark-length data is a recording pulse pattern of recording pulses rising from an erasing power and formed between a recording power larger than the erasing power and a bottom power smaller than the erasing power and of erasing pulses rising from the bottom power to the erasing power. A recording light beam is then irradiated onto the recording layer in accordance with the recording pulse pattern to record at least one recorded mark representing the information to be recorded. Used in recording is an optimum erasing power, as the erasing power, the optimum erasing power satisfying an expression (1): 1.000<(R1/R0)<1.030 . . .

Abstract: An optical disk consists of a first laminated layer structure and a second laminated layer structure. The first structure has a first transparent substrate having a first surface and a second surface on both sides thereof, provided on the first surface being a light-incident plane via which a light beam is to be incident in recording or reproduction, formed alternately on the second surface being a plurality of first lands and first grooves, and a first organic-dye recording layer formed on the second surface to cover the first lands and grooves. The second structure has a second substrate, alternately formed on which are a plurality of second lands and second grooves, a reflective film formed on the second transparent substrate to cover the second lands and grooves, and a second organic-dye recording layer formed on the reflective film to face the second transparent substrate.

Abstract: The present invention provides a thin magnetic tape for allowing a long play without degrading electro-magnetic transfer characteristics and mechanical strength of the magnetic tape. The magnetic tape comprises a base film, an an under layer provided on the base film, and a magnetic layer containing magnetic particles coated on the under layer. The under layer contains magnetic plate-particles each having a configuration such that a ratio of a major axis to a minor axis observed in a plate-like surface is preferred to be approximately 1 and a ratio of the major axis to a thickness off the magnetic particles is to be 5.about.10 so that the under layer has Young's modulus of not less than 2.0.times.10.sup.10 N/m.sup.2 in a longitudinal direction of the magnetic tape and has virtually the same value in a traversing direction thereof.