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: An optical disc has a first transparent substrate, a second substrate, and at least a first and a second recording layer formed between the substrates. The first substrate has a first surface and an opposing second surface, the first surface is a beam incidence surface for a laser beam, the second surface having a first concave section and a first convex section formed adjacent to each other thereon, the first concave section being farther than the first convex section from the incidence surface, first pre-pits being formed on the first concave section. The second substrate has a second concave section and a second convex section formed adjacent to each other thereon, the second concave section being farther than the second convex section from the incidence surface, second pre-pits being formed on the second concave section, a top surface of each second pre-pit being closer than a top surface of the second convex section to the beam surface.

Abstract: An optical disc has a first transparent substrate and a second substrate. The first substrate has a first surface and an opposing second surface. The first surface is a beam incidence surface for a laser beam in recording or reproduction of data. The second surface has first concave sections and first convex sections alternately formed thereon. The first concave sections are closer than the first convex sections to the beam incidence surface. The first convex sections have first top portions and first bottom portions closer than the first top portions to the beam incidence surface. First pre-pits carrying auxiliary information related to the data is formed on the first top portions. Each first top portion has a first width orthogonal to a direction of tracks on the first substrate. A second width orthogonal to the above direction between two first top portions of adjacent first convex sections having a first concave section therebetween is narrower than the first width.

Abstract: An optical disk has a first and a second intermediate disk structure. The first structure includes at least a first transparent substrate, a first recording layer, and a first reflective layer. The first substrate has a first surface and a second surface. The first surface is a beam incidence surface for a laser beam in recording or reproduction of data. The second surface has a first concave section and a first convex section formed thereon. The first recording layer and the first reflective layer are stack in order on the second surface via the first concave and convex sections. The second structure includes at least a second substrate, a second reflective layer, and a second recording layer. The second substrate has a second concave section and a second convex section formed thereon. The second reflective layer and the second recording layer are stack in order on the second substrate via the second concave and convex sections.

Abstract: An optical storage medium has a first layer structure and a second layer structure. The first layer structure includes a first substrate having a light-incident surface via which light is incident for recording or reproduction and a first surface having first concave sections and first convex sections, formed in order on the first surface being at least a first recording layer and a semi-transparent film, the first convex sections sticking out toward the light-incident surface, first recording tracks being provided on first portions of the first recording layer, the first portions corresponding to the first convex sections that are wobbling at a fixed frequency between an inner edge and an outer edge of the optical storage medium.

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: When an LPP (land pre-pit) is formed between shallow grooves or shallow pits, the LPP is formed on a land existing between the shallow grooves or the shallow pits. Further, the LPP is formed in a position displaced from a centerline of the land in the radial direction by a predetermined amount. Furthermore, a laser beam power utilized for forming a shallow groove or a shallow pit adjacent to the LPP is reduced so as to be lower than a regular laser beam power.

Abstract: A method for manufacturing a disk substrate for mass production of a phase change optical disk, wherein an original disk substrate is having a resist layer (2) applied on a glass substrate (1), composed of the steps of forming a depression (pit “p1” and groove “g1”) having a first and a second depth by cutting laser to be exposed on the surface of the resist layer (2), etching the depression having the first depth and the second depth from the surface of the resist layer (2) of the disk substrate in atmosphere mixed with Argon and Oxygen in ratio of 10 to 90% under gas pressure of 0.1 to 1.5 Pa, wherein the first and the second depth of the depression (pit “p1” and groove “g1”) become predetermined value respectively, and ashing the resist layer (2) from the glass substrate (1).

Abstract: When an LPP (land pre-pit) is formed between shallow grooves or shallow pits, the LPP is formed on a land existing between the shallow grooves or the shallow pits. Further, the LPP is formed in a position displaced from a centerline of the land in the radial direction by a predetermined amount. Furthermore, a laser beam power utilized for forming a shallow groove or a shallow pit adjacent to the LPP is reduced so as to be lower than a regular laser beam power.

Abstract: A method for manufacturing a disk substrate for mass production of a phase change optical disk, wherein an original disk substrate is having a resist layer (2) applied on a glass substrate (1), composed of the steps of forming a depression (pit “p1” and groove “g1”) having a first and a second depth by cutting laser to be exposed on the surface of the resist layer (2), etching the depression having the first depth and the second depth from the surface of the resist layer (2) of the disk substrate in atmosphere mixed with Argon and Oxygen in ratio of 10 to 90% under gas pressure of 0.1 to 1.5 Pa, wherein the first and the second depth of the depression (pit “p1” and groove “g1”) become predetermined value respectively, and ashing the resist layer (2) from the glass substrate (1).