Abstract: An optical disc molding device has a pair of molds for injection molding a disc substrate within cavities, and a stamper supported within at least one cavity, for molding a data recording surface in such a manner that the inside diameter side of the stamper supporting surface of the cavity protrudes inwardly in the disc thickness direction from the data recording surface. The flatness of a laminated reference plane has thus been deteriorated by burrs occurring on a disc substrate.

Abstract: An optical recording medium capable of recording and/or reproducing an information by using a laser beam, comprising: a support layer having an information signal-recording portion on one side surface thereof on which said laser beam is incident, and a transparent layer disposed over the support layer and having a thickness smaller than that of the support layer. In accordance with the present invention, there are further provided production method for optical or magneto-optical discs whereby a high density reproduction can be achieved.

Abstract: Digital information is recorded with high density. Positions of a leading edge and a trailing edge of an information pit are shifted from a reference position indicated by a leading edge of a reference clock in a step-wise fashion in respond to digital data to be recorded.

Abstract: Digital information is recorded with high density. Positions of a leading edge and a trailing edge of an information pit are shifted from a reference position indicated by a leading edge of a reference clock in a step-wise fashion in response to digital data to be recorded.

Abstract: Digital information is recorded with high density. Positions of a leading edge and a trailing edge of an information pit are shifted from a reference position indicated by a leading edge of a reference clock in a step-wise fashion in response to digital data to be recorded.

Abstract: A multi-layer recording medium including a light-transmitting substrate, a first information recording layer formed on the substrate, an intermediate layer at least part of which is formed of a photo-curable resin film, and which is formed on the first information recording layer, a second information recording layer formed on a surface of the intermediate layer opposite to the surface facing the first information signal layer, and a protective layer formed on the second information signal layer. A method for producing such multi-layer recording medium is also disclosed.

Abstract: A mastering method for making a high recording density optical disk is disclosed, in which a substrate with a photosensitive material layer is selectively exposed to a focused laser light having a predetermined power representing information to be recorded. The laser power is such that the exposed width at the top surface of the photosensitive material layer is larger than the exposed width at the bottom surface of the photosensitive material layer. After the development of the layer, the remaining photosensitive material layer is used as an etching mask for the substrate to form pits in the substrate.

Abstract: In a making method for a high-density optical disk, comprising the step of forming recording pits or recesses for forming the recording pits by etching through apertures of a photoresist layer, a light intensity distribution of an exposure beam spot for forming each aperture through the photoresist layer is made different between a circumferential direction of the optical disk and a direction perpendicular to the circumferential direction, thereby setting a ratio between a length of each pit and a length of each land in respect of the circumferential direction to about 1.

Abstract: A developing apparatus of photoresist for controlling development of a photoresist formed on a light-transmitting substrate and having a latent image produced by exposure thereof to an irradiation for equi-pitch patterns, adapted to detect monitor light diffracted by the equi-pitch patterns produced as development of the resist advances after the diffracted light is totally reflected at the opposite surface to the surface through which it is let in and diffracted again by the equi-pitch patterns and the developing process is controlled according to a signal obtained as the result of the detection.