Abstract: An optical recording medium wherein characters can be easily recognized on an optical disk irradiated with a light through a light transmitting layer and a method of producing the same are provided. In an optical disk of a type that an optical recording layer is irradiated with a light through a light transmitting protective layer, dealing with a larger capacity, wherein one main surface of a medium substrate 15 is divided to a signal portion SG and a character portion CA, a signal portion uneven shape (15p) is formed on the signal portion SG and a character portion uneven shape (15p) is formed on the character portion CA, and depths of the signal portion uneven shape and the character portion uneven shape are 25 nm or less. Here, it is configured that characters are recorded to be able to be read as normal characters when looking from the medium substrate 15 side (Y-direction) by outlines of a region formed with the character portion uneven shape on the character portion CA.

Abstract: A large capacity recording medium is formed by bonding at least two disc-shaped recording plates to provide a structure adapted to absorb any manufacturing errors in the direction of the height of the recording medium.

Abstract: The S/N ratio is improved for recording data to grooves (2-1,2-2) of an optical disc so that as much information as possible can be recorded at the lowest possible frequency band. An optical disc using wobble patterns to record different information has a first groove (2-1) having a first wobble pattern (22) in which one wobble period has a sharp rising edge and a gradual falling edge; and a second groove (2-2) having a second wobble pattern (24) in which one wobble period has a gradual rising edge and a sharp falling edge. Each of the first and the second wobble pattern is represented by a first fundamental and a second harmonic of a Fourier series. The polarity of the second harmonic, which is an even harmonic, of the second wobble pattern is opposite that of the first wobble pattern. A method for manufacturing this optical disc is also provided.

Abstract: A stamper and optical disk. A photoresist is applied to a substrate and this photoresist is exposed, developed and then transferred to form a disk master which has a recess/protrusion pattern formed on its one side. The one side of the disk master is etched to narrow the width of a protruding part constituting the recess/protrusion pattern, and the recess/protrusion pattern of the disk master with the reduced width of the protruding part is transferred to form a stamper. The recess/protrusion pattern provided on the stamper is transferred to form a predetermined pattern on a substrate of an optical disk.

Abstract: A data area to record and/or reproduce data and an eccentricity measuring area 14 in which a groove area formed with spiral grooves and a planer mirror area are spatially alternately arranged are provided for a disc substrate. A width of groove area formed in the eccentricity measuring area, a width of mirror area, and an interval between the grooves in the groove area are selected so that a conventional mechanical characteristics measuring apparatus can track a plurality of grooves formed in the groove area as if the grooves were a single groove.

Abstract: An electron beam irradiation apparatus, includes a support section for supporting an electron beam irradiation subject to be irradiated with an electron beam, and an electron beam irradiation head opposed to the electron beam irradiation subject via a minute space, the electron beam irradiation head having an electron beam emission hole for irradiating the electron beam irradiation subject with the electron beam. In the electron beam irradiation head, an electron beam path communicating with the electron beam emission hole is provided, and in addition one or more ring shaped gas suction grooves opened from a surface of the electron beam irradiation head facing the electron beam irradiation subject is formed around the electron beam emission hole. Vacuum pumps are coupled to the electron beam path and the ring shaped gas suction grooves, and the electron beam path is held in a high vacuum state.

Abstract: The present invention provides an optical recording medium and an optical disk device realizing prevention of crosswrite and uniformity of playback signals and capable of easily securing compatibility with a read only disk. It provides an optical recording medium on which light LB condensed by a lens (12, 14) having a numerical aperture of 0.85±0.

Abstract: The present invention provides an optical recording medium and an optical disk device realizing prevention of crosswrite and uniformity of playback signals and capable of easily securing compatibility with a read only disk. It provides an optical recording medium on which light LB condensed by a lens (12, 14) having a numerical aperture of 0.85±0.

Abstract: A large capacity recording medium is formed by bonding at least two disc-shaped recording plates to provide a structure adapted to absorb any manufacturing errors in the direction of the height of the recording medium.

Abstract: The present invention provides an optical recording medium and an optical disk device realizing prevention of crosswrite and uniformity of playback signals and capable of easily securing compatibility with a read only disk. It provides an optical recording medium on which light LB condensed by a lens (12, 14) having a numerical aperture of 0.85±0.

Abstract: The present invention provides an optical recording medium and an optical disk device realizing prevention of crosswrite and uniformity of playback signals and capable of easily securing compatibility with a read only disk. It provides an optical recording medium on which light LB condensed by a lens (12, 14) having a numerical aperture of 0.85±0.

Abstract: This invention relates to a stamper for optical disc and a method for manufacturing an optical disc by using this stamper. A photoresist is applied to a substrate (2) and this photoresist is exposed, developed and then transferred to form a disc master which has a recess/protrusion pattern formed on its one side. The one side of the disc master (20) is etched to narrow the width of a protruding part constituting the recess/protrusion pattern, and the recess/protrusion pattern of the disc master (20) with the reduced width of the protruding part is transferred to form a stamper (30). The recess/protrusion pattern provided on the stamper (30) is transferred to form a predetermined pattern on a substrate of an optical disc.

Abstract: The present invention provides an optical recording medium and an optical disk device realizing prevention of crosswrite and uniformity of playback signals and capable of easily securing compatibility with a read only disk. It provides an optical recording medium on which light LB condensed by a lens (12, 14) having a numerical aperture of 0.85±0.

Abstract: The S/N ratio is improved for recording data to grooves (2-1,2-2) of an optical disc so that as much information as possible can be recorded at the lowest possible frequency band. An optical disc using wobble patterns to record different information has a first groove (2-1) having a first wobble pattern (22) in which one wobble period has a sharp rising edge and a gradual falling edge; and a second groove (2-2) having a second wobble pattern (24) in which one wobble period has a gradual rising edge and a sharp falling edge. Each of the first and the second wobble pattern is represented by a first fundamental and a second harmonic of a Fourier series. The polarity of the second harmonic, which is an even harmonic, of the second wobble pattern is opposite that of the first wobble pattern. A method for manufacturing this optical disc is also provided.

Abstract: An optical recording medium wherein characters can be easily recognized on an optical disk irradiated with a light through a light transmitting layer and a method of producing the same are provided. In an optical disk of a type that an optical recording layer is irradiated with a light through a light transmitting protective layer, dealing with a larger capacity, wherein one main surface of a medium substrate 15 is divided to a signal portion SG and a character portion CA, a signal portion uneven shape (15p) is formed on the signal portion SG and a character portion uneven shape (15p) is formed on the character portion CA, and depths of the signal portion uneven shape and the character portion uneven shape are 25 nm or less. Here, it is configured that characters are recorded to be able to be read as normal characters when looking from the medium substrate 15 side (Y-direction) by outlines of a region formed with the character portion uneven shape on the character portion CA.

Abstract: This invention relates to a manufacturing method for an optical information recording medium and a manufacturing device for an optical information recording medium, and is applicable for instance to devices for optical disks, capable of focusing a laser beam from an exposure semiconductor laser at high density onto a base disk. This invention compensates the chromatic aberrations of the objective lens with a chromatic aberration optical system or compensates for fluctuations in the wavelength by regulating the temperature of the semiconductor laser.

Abstract: This invention relates to a stamper for optical disc and a method for manufacturing an optical disc by using this stamper. A photoresist is applied to a substrate (2) and this photoresist is exposed, developed and then transferred to form a disc master which has a recess/protrusion pattern formed on its one side. The one side of the disc master (20) is etched to narrow the width of a protruding part constituting the recess/protrusion pattern, and the recess/protrusion pattern of the disc master (20) with the reduced width of the protruding part is transferred to form a stamper (30). The recess/protrusion pattern provided on the stamper (30) is transferred to form a predetermined pattern on a substrate of an optical disc.

Abstract: The present invention provides an optical recording medium and an optical disk device realizing prevention of crosswrite and uniformity of playback signals and capable of easily securing compatibility with a read only disk. It provides an optical recording medium on which light LB condensed by a lens (12, 14) having a numerical aperture of 0.85±0.

Abstract: There are provided an optical recording medium and a method of manufacturing the optical recording medium. The optical recording medium has a pattern of microscopic depressions and projections molded thereon with a high fidelity of replication. The method of manufacturing the optical recording medium comprises the steps of forming a photoresist layer on a substrate; exposing a predetermined area of the photoresist layer formed on the substrate to form a plurality of trains of depressions in the photoresist layer; removing the photoresist layer between the adjoining depression trains to form a master; plating the master with a metal; separating the metal coating to form a master stamper; replicating the master stamper repeatedly an odd number of times to form a mother stamper; replicating the mother stamper to form a resin substrate; and forming at least a light-transparent layer on a surface of the resin substrate on which the mother stamper is replicated.

Abstract: The present invention provides a recording medium of one-side address method capable of easily detecting a synchronous signal and production method of recording medium master used for such a recording medium. The recording medium master production method according to the present invention includes a photo-sensitive layer exposure step using a first beam and a second beam for exposure of walls of a groove in a straight line, wherein for exposure of an area where a synchronous signal is to be recorded, the second beam alone is used while being wobbled according to the synchronous signal.