Abstract: A magneto-optical recording medium (X1) comprises a substrate (S1) and a material film structure. The substrate (S1) includes a pre-groove surface (11a) with a pre-groove (11b) formed therein, and at least the pre-groove surface (11a) is made of a soft magnetic material. The material film structure comprises a recording magnetic section (21) for executing a recording function and a reproduction function and is provided on a pre-groove surface (11a) of the substrate (S1).

Abstract: The magneto-optical recording medium (X1) includes a resin substrate (S1) having a pre-groove surface (1a) on which pre-grooves (1b) are formed, a recording magnetic section (11) performing a recording function and a reproduction function, a soft magnetic plating layer (12) provided between the resin substrate (S1) and the recording magnetic section (11), and a bonding layer (13) interposed between the resin substrate (S1) and the soft magnetic plating layer (12) for enhancing attachment between the resin substrate (S1) and the soft magnetic plating layer (12).

Abstract: A magneto-optical recording medium (D1) includes a soft magnetic layer (1), a groove forming layer (3), and a magneto-optical recording layer (4), successively laminated on a substrate (1). The substrate (1) is made of resin. At least a part of the surfaces of the substrate 1 held in contact with the soft magnetic layer (2) has a surface roughness of no less than 4 nm, thereby improving adhesion between the substrate (1) and the soft magnetic layer (2). Since the substrate (1) is made of resin, the production cost can be reduced.

Abstract: An optical disk (D) is provided with multiple grooves (G) and multiple lands (L) alternating with each other. The address data recording regions have a pair of wobbling sections (31a, 31b) formed on both sidewalls of a groove (G) and having an identical phase. Thus, it is possible to obtain push-pull signals having a larger amplitude, which is advantageous for increasing the data recording density.

Abstract: The present invention provides a shape replication method characterized by comprising the steps of: fixing to a table a stamper having a predetermined pattern on its surface and a center opening; supplying a photocurable resin onto the patterned surface of the stamper; setting a thin-plate-like substrate having an opening smaller in diameter than the opening of the stamper on the photocurable resin so as to keep the substrate at a predetermined position relative to the stamper; applying light from above the substrate to cure the photocurable resin; and pressing a stripping member that is insertable into the opening of the stamper against a portion of the substrate surrounding its opening and extending beyond the opening of the stamper to strip off the photocurable resin integral with the substrate from the stamper.

Abstract: The invention is a magneto-optical recording medium characterized by containing at least a soft magnetic layer, a protective layer, a resin layer having a servo pattern formed thereon, a reflecting film, a lower dielectric material film, a recording film, an upper dielectric material film, and a cover layer, formed on a substrate in this order.

Abstract: A magneto-optical disk having recording tracks are formed along concentric grooves or a spiral groove. A non-groove region where no grooves are made is provided in a middle part of each recording track. In the non-groove region, there is formed a pit pattern representing information about the recording track. A track-counting U-groove is formed in the non-groove region, for detecting that the light spot of a reading laser beam has moved across the recording track. With the disk thus structured, it is possible to record information at high density and to access a desired recording track at high speed.

Abstract: The present invention provides an optical disk comprising: at least a rewritable region and a read-only data region, wherein the rewritable region includes a plurality of groove tracks and a plurality of land tracks, the read-only data region includes a plurality of groove tracks and a plurality of land tracks, read-only data comprising control data are written as concavo-convex pits to the groove tracks and/or the land tracks in the read-only data region, and the width of each groove in the read-only data region is smaller than that of each groove in the rewritable region. According to the first optical disk of the present invention, the area of rewritable regions for users can be ensured as broadly as possible failing to deteriorate the high-speed performance of the system.

Abstract: In a rewritable optical recording medium, a recording surface is divided into a plurality of zones by setting pitch intervals in the radial direction to be constant and a data area and a spare area for a defective sector are allocated in each zone. As for a capacity of the spare area in each zone, a predetermined total capacity of spare areas is allocated so that a spare ratio K=D1/D2 of a capacity D2 of the spare areas for a capacity D1 of the data areas becomes almost the same in the zones.

Abstract: Using MSR (magnetically induced super-resolution) technology, a read-head field is applied to a magneto-optical recording medium when reading an information signal from a recording layer of a magneto-optical recording medium, in order to magnetize the read light-irradiated magnetic layer in one direction in a part of an area within the read light spot. The magneto-optical recording medium using MSR technology adopts the on-land recording method in which an information signal is written to the land, which enables read of an information signal by the MSR technology with a smaller read-head field.

Abstract: A recording medium suitable for magnetic super resolution reproduction and a process for manufacturing the medium are provided, in which land and groove recording is adopted and an intensity of a magnetic field for reproduction is reduced. The recording medium has the land and the groove, both of which are used for recording information. At least one of the land and the groove has an edge portion whose radius of curvature is greater than one sixth of the width of the land or the groove. The radius of curvature of the edge portion is enlarged by the process such as spatter etching of the substrate, deformation of a resist pattern by heating, ozone etching by ultraviolet rays.

Abstract: A magneto-optical disk 10 having recording tracks 11 are formed along concentric grooves 12 or a spiral groove 12. A non-groove region where no grooves 12 are made is provided in a middle part of each recording track 11. In the non-groove region there is formed a pit pattern representing information about the recording track 11. A track-counting U-groove 14 is formed in the non-groove region, for detecting that the light spot of a reading laser beam has moved across the recording track 11.

Abstract: The present invention is a system capable of protecting copyright and personal information appropriately and allowing users to readily obtain desired contents in a short time at low prices. A recording device stores contents in advance. The recording device encrypts the contents, based on an identifier given uniquely to a medium. The recording device records the encrypted contents on the medium. Moreover, the recording device records limiting conditions for reproducing, displaying or executing the contents on the medium. An execution device decrypts the contents recorded on the medium, based on the identifier. The execution device reproduces, displays or executes the contents under the limiting conditions recorded on the medium.

Abstract: On the assumption that a phase difference caused by a birefringence at the substrate is &phgr;br while a one caused by the magneto-optic Kerr effect of the recording layer is &phgr;MO, the magneto-optical recording medium formatted to record information in the groove meets the conditions: −20°<&phgr;br<+10° and −45°<(&phgr;br+&phgr;MO)<+15°, the magneto-optical recording medium formatted to record information on the land meets the conditions: −20°<&phgr;br<+10° and −15°<(&phgr;br+&phgr;MO)<+45°, and the magneto-optical recording medium formatted to record information at both the land and groove meets the conditions: −20°<&phgr;br<+10° and −15°<(&phgr;br+&phgr;MO)<+15°.

Abstract: An optical recording medium in which information can be recorded in tracks formed by both lands and grooves provided between lands, and rows of prepits corresponding to preformat information in both adjacent lands and grooves are formed by deviating in the circumferential direction. Counting grooves for counting tracks are formed at both sides of the row of prepits for the land, the prepit for the groove has a depth or width different from that of the groove, the counting groove has a depth or width different from that of the groove, and the prepit for the land is formed narrower and/or shallower than the counting groove.

Abstract: An information recording medium wherein the key information is recorded by arrangement of a unit area recorded irreversibly and a unit area not recorded irreversibly to effect the truth judgment of the medium in accordance with the result of whether or not the reproduction of the key information can be effected, the information recording medium where the illegal usage of the medium is adapted to be prevented without inputting the information on to the medium truth judgment into the processing apparatus by provision of the medium firm information, a reproducing method for the same, a truth judging method for the same, and a recording/reproducing apparatus for the same.

Abstract: The invention provides an optical recording medium in which a medium judge code for confirming genuineness of the medium as well as a medium identification code peculiar to the medium are recorded as labels for preventing illegal copy of the optical recording medium and illegal usage of recorded data therein, so as to decrease the degree of degradation of the area for the medium identification code, and also provides a reproducing method for the optical recording medium.

Abstract: An optical recording medium in which a medium identification code is recorded as a nonvolatile mark which is formed through irreversible change of a recording film, such as magnetization characteristic change, deformation and formation of a hole, so as to prevent illegal copying of the optical recording medium, and a recording/reproducing method for the same.

Abstract: An optical disk is made up of a disk-shaped substrate having a surface, a first track and a second track provided on the surface of the substrate, where the first and second tracks are two mutually adjacent concentric tracks or two mutually adjacent track turns of a single spiral track, the first track extends along a first center line and the second track extends along a second center line, and an identification signal recording part extending along a third center line and prerecorded with an identification signal including at least a sector number and a track number for identifying a position on the optical disk. The third center line is arranged between the first and second center lines, and the identification signal prerecorded in the identification signal recording part is common to the first and second tracks on both sides of the identification signal recording part.

Abstract: An optical disk cartridge includes a cartridge body formed with an opening at an edge thereof such that an optical disk can be taken out and returned from and to the optical disk cartridge. The opening is closed by a cover lid that is formed as an integral body of the cartridge body.