Abstract: An optical disk storing write-once information usable for protecting the copyright of the software by preventing the duplication, unauthorized use, etc., of the software. In the optical disk, a recording layer (213) is formed on a disk substrate (211) with a dielectric layer (212) inbetween. Then, an intermediate dielectric layer (214) and a reflecting layer (215) are successively laminated upon the recording layer (213), and an overcoat layer (216) is formed on the surface of the reflecting layer (215). A plurality of BCA (one of write-once identification information systems) sections (220a and 220b) are recorded by lowering the vertical magnetic anisotropy of the recording layer (213). At the time of reproduction, the write-once information is detected from differential signals.

Abstract: A content recording method using a communication means, including reading from a recording medium identification information unique to that recording medium, receiving through the communication means permission information for permitting recording of content on that recording medium, receiving content information through the communication means, and after confirming validity of the permission information, encrypting the received content information using both the unique identification information and a cipher key, and recording the encrypted content information on the recording medium.

Abstract: The operating and other procedures of a disk or recording medium application system of the type for which a network is used are simplified. Disks or recording media have auxiliary data recording areas, where different IDs for individual disk, and/or cipher keys and/or decoding keys for ciphers are recorded in advance in a factory. By using the IDs to release the soft ciphers, and using the cipher keys when sending the ciphers, and using the decoding keys when receiving the ciphers, user authorization procedures are simplified.

Abstract: An optical recording medium such as DVD has a data recording area (103) in which data can be rewritten and a write-once area (104) in which data can be written only once and not be erased. A medium specific ID (105) which is specific to an optical recording medium is recorded in the write-once area (104). In the data recording area (103), a reflectance ratio of a part where the data is recorded is different from a reflectance ratio in a part where the data is not recorded. A reflectance ratio of a recording pit formed in the write-once area (104) is higher than the higher one of the reflectance ratios in the part where the data is recorded and in the part where the data is not recorded in the data recording area (103). Data recoding in the write-once area (104) is performed by irradiating to the write-once area (104) a laser beam with heat amount of three to 25 times heat amount necessary for recording rewritable data in the data recording area (103).

Abstract: An optical disc that has a recognition mark area behind a recorded area and in which the last data in the recorded area is stably accessed, the recognition mark area can be accessed without bringing about an abnormal state, and the first data in a succeeding recorded area, if it exists, is stably accessed. An unrecorded area (5) is provided outside the recorded area (4) of the optical disc (1). A mark area (6) is provided between the recorded area (4) and unrecorded area (5). A recognition mark area (6d) is provided in the mark area (6) in order to recognize the boundary between the recorded area (4) and the unrecorded area (5). In the mark area (6), first and second buffer areas (6b and 6c) are provided respectively in front of and behind the recognition mark area (6d).

Abstract: A reproduction apparatus is provided for reproducing information stored on an optical medium. The apparatus includes a light source for illuminating the optical medium, the optical medium having at least one surface containing information stored thereon; a focusing arrangement operable to focus the light source on the at least one surface containing information thereon; and a detection arrangement operable to detect the information stored on the optical medium. The optical medium includes a first substrate having a first information surface; a semitransparent reflection film formed on the first information surface of the first substrate; a second substrate having a second information surface; a reflection film formed on the second information surface of the second substrate; and an adhesive layer for adhering the first substrate and the second substrate so that the first information surface and the second information surface face each other, wherein the thickness of the first substrate is at least 0.

Abstract: A reproduction apparatus is provided for reproducing information stored on an optical medium. The apparatus includes a light source for illuminating the optical medium, the optical medium having at least one surface containing information stored thereon; a focusing arrangement operable to focus the light source on the at least one surface containing information thereon; and a detection arrangement operable to detect the information stored on the optical medium. The optical medium includes a first substrate having a first information surface; a semitransparent reflection film formed on the first information surface of the first substrate; a second substrate having a second information surface; a reflection film formed on the second information surface of the second substrate; and an adhesive layer for adhering the first substrate and the second substrate so that the first information surface and the second information surface face each other, wherein the thickness of the first substrate is at least 0.

Abstract: A reproduction apparatus is provided for reproducing information stored on an optical medium. The apparatus includes a light source for illuminating the optical medium, the optical medium having at least one surface containing information stored thereon; a focusing arrangement operable to focus the light source on the at least one surface containing information thereon; and a detection arrangement operable to detect the information stored on the optical medium. The optical medium includes a first substrate having a first information surface; a semitransparent reflection film formed on the first information surface of the first substrate; a second substrate having a second information surface; a reflection film formed on the second information surface of the second substrate; and an adhesive layer for adhering the first substrate and the second substrate so that the first information surface and the second information surface face each other, wherein the thickness of the first substrate is at least 0.

Abstract: A reproduction apparatus is provided for reproducing information stored on an optical medium. The apparatus includes a light source for illuminating the optical medium, the optical medium having at least one surface containing information stored thereon; a focusing arrangement operable to focus the light source on the at least one surface containing information thereon; and a detection arrangement operable to detect the information stored on the optical medium. The optical medium includes a first substrate having a first information surface; a semitransparent reflection film formed on the first information surface of the first substrate; a second substrate having a second information surface; a reflection film formed on the second information surface of the second substrate; and an adhesive layer for adhering the first substrate and the second substrate so that the first information surface and the second information surface face each other, wherein the thickness of the first substrate is at least 0.

Abstract: An optical disk storing write-once information usable for protecting the copyright of the software by preventing the duplication, unauthorized use, etc., of the software. In the optical disk, a recording layer (213) is formed on a disk substrate (211) with a dielectric layer (212) inbetween. Then, an intermediate dielectric layer (214) and a reflecting layer (215) are successively laminated upon the recording layer (213), and an overcoat layer (216) is formed on the surface of the reflecting layer (215). A plurality of BCA (one of write-once identification information systems) sections (220a and 220b) are recorded by lowering the vertical magnetic anisotropy of the recording layer (213). At the time of reproduction, the write-once information is detected from differential signals.

Abstract: An optical recording medium is provided which includes a first substrate having a first information surface, a semitransparent reflection film formed on the first information surface of the first substrate, and a second substrate having a second information surface. In addition, the optical recording medium includes a reflection film formed on the second information surface of the second substrate, and an adhesive layer for adhering the first substrate and the second substrate so that the first information surface of the first substrate faces the second information surface on the second substrate. The thickness of the first substrate is the same as the thickness of the second substrate.

Abstract: An optical disk having a first recording area for recording information; and a second recording area having auxiliary information including disk identification information unique to that optical disk recorded therein, wherein the second recording area including circumferentially arranged multiple stripe patterns each strip extending along a radius of the disk; and indicator indicating the presence of auxiliary information.

Abstract: Four ECC blocks are recorded in a burst cutting area of an optical disc. Each ECC block is constituted by a BCA content code of 1 byte, content data length of 1 byte, and content data of 14 bytes. Of the BCA content data, the leading 6 bits are used for application ID and the remaining 2 bits are used for block number. Disc ID is stored in the content data. Since the four ECC blocks exist, the optical disc can be managed individually by four applications at the maximum. Thus it becomes possible to manage the same optical disc by a plurality of applications.

Abstract: An optical disc that has a recognition mark area behind a recorded area and in which the last data in the recorded area is stably accessed, the recognition mark area can be accessed without bringing about an abnormal state, and the first data in a succeeding recorded area, if it exists, is stably accessed. An unrecorded area (5) is provided outside the recorded area (4) of the optical disc (1). A mark area (6) is provided between the recorded area (4) and unrecorded area (5). A recognition mark area (6d) is provided in the mark area (6) in order to recognize the boundary between the recorded area (4) and the unrecorded area (5). In the mark area (6), first and second buffer areas (6b and 6c) are provided respectively in front of and behind the recognition mark area (6d).

Abstract: The operating and other procedures of an optical disk application system of the type for which a network is used are simplified. Optical disks have auxiliary data recording areas, where different IDs for individual disks, and/or cipher keys and/or decoding keys for ciphers are recorded in advance in a factory. By using the IDs to release the soft ciphers, using the cipher keys when sending the ciphers, and using the decoding keys when receiving the ciphers, user authorization procedures are simplified.

Abstract: The operating and other procedures of an optical disk application system of the type for which a network is used are simplified. Optical disks have auxiliary data recording areas, where different IDs for individual disks, and/or cipher keys and/or decoding keys for ciphers are recorded in advance in a factory. By using the IDs to release the soft ciphers, using the cipher keys when sending the ciphers, and using the decoding keys when receiving the ciphers, user authorization procedures are simplified.

Abstract: A reproduction apparatus is provided for reproducing information stored on an optical medium. The apparatus includes a light source for illuminating the optical medium, the optical medium having at least one surface containing information stored thereon; a focusing arrangement operable to focus the light source on the at least one surface containing information thereon; and a detection arrangement operable to detect the information stored on the optical medium. The optical medium includes a first substrate having a first information surface; a semitransparent reflection film formed on the first information surface of the first substrate; a second substrate having a second information surface; a reflection film formed on the second information surface of the second substrate; and an adhesive layer for adhering the first substrate and the second substrate so that the first information surface and the second information surface face each other, wherein the thickness of the first substrate is at least 0.

Abstract: A reproduction apparatus is provided for reproducing information stored on an optical medium. The apparatus includes a light source for illuminating the optical medium, the optical medium having at least one surface containing information stored thereon; a focusing arrangement operable to focus the light source on the at least one surface containing information thereon; and a detection arrangement operable to detect the information stored on the optical medium. The optical medium includes a first substrate having a first information surface; a semitransparent reflection film formed on the first information surface of the first substrate; a second substrate having a second information surface; a reflection film formed on the second information surface of the second substrate; and an adhesive layer for adhering the first substrate and the second substrate so that the first information surface and the second information surface face each other, wherein the thickness of the first substrate is at least 0.

Abstract: A content recording method using a communication means, including reading from a recording medium identification information unique to that recording medium, receiving through the communication means permission information for permitting recording of content on that recording medium, receiving content information through the communication means, and after confirming validity of the permission information, encrypting the received content information using both the unique identification information and a cipher key, and recording the encrypted content information on the recording medium.

Abstract: A reproduction apparatus is provided for reproducing information stored on an optical medium. The apparatus includes a light source for illuminating the optical medium, the optical medium having at least one surface containing information stored thereon; a focusing arrangement operable to focus the light source on the at least one surface containing information thereon; and a detection arrangement operable to detect the information stored on the optical medium. The optical medium includes a first substrate having a first information surface; a semitransparent reflection film formed on the first information surface of the first substrate; a second substrate having a second information surface; a reflection film formed on the second information surface of the second substrate; and an adhesive layer for adhering the first substrate and the second substrate so that the first information surface and the second information surface face each other, wherein the thickness of the first substrate is at least 0.