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: When recording and reproduction are performed at the same time, if a system controller detects that an amount of data accumulated in a buffer memory exceeds a predetermined value, the system controller stops data reading from an optical disk 109 temporarily and records data accumulated in the buffer memory continuously to the optical disk. Then, an image is prevented from becoming abnormal when a reproduction position catches up to a recording position. Further, a system controller monitors a zone in an optical disk, to which recording is performed and controls a motor at an appropriate revolution number for the recording to the zone. Further, reproduction is performed by maintaining the revolution number. Then, even if the recording position and the reproduction position belong to different zones in a recording medium, a transition time from recording to reproduction is prevented from becoming long.

Abstract: When recording and reproduction are performed at the same time, if a system controller detects that an amount of data accumulated in a buffer memory exceeds a predetermined value, the system controller it stops data reading from an optical disk 109 temporarily and records data accumulated in the buffer memory continuously to the optical disk. Then, an image is prevented from becoming abnormal when a reproduction position catches up to a recording position. Further, a system controller monitors a zone in an optical disk, to which recording is performed and controls a motor at an appropriate revolution number for the recording to the zone. Further, reproduction is performed by maintaining the revolution number. Then, even if the recording position and the reproduction position belong to different zones in a recording medium, a transition time from recording to reproduction is prevented from becoming long.

Abstract: An optical disk recordable by a recording device and having first and second recording areas, the second recording area having recorded therein disk identification information unique to the disk, and multiple cipher keys, the first recording area being capable of having recorded therein information that is encrypted by using the disk identification information and one of the multiple cipher keys during recording.

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 device for recording information on an optical disk having first and second recording areas, which device can record information into the first recording area, using a first modulation method; read disk identification information recorded by a second modulation method in the second recording area; detect auxiliary information indicating the presence of disk identification information; encrypt information using both a cipher key and the disk identification information unique to the optical disk; and permit recording of encrypted information after confirming the presence of the disk identification information.

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 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 optical disk of this invention includes a read-only area in which a plurality of read-only tracks are formed and a rewritable area in which a plurality of rewritable tracks are formed, wherein each of the plurality of read-only tracks is divided into a plurality of first sectors, a signal is prerecorded in at least one of the plurality of first sectors under a predetermined reproduction format, each of the plurality of rewritable tracks is divided into a plurality of second sectors, a signal is recordable in at least one of the plurality of second sectors under a predetermined recording format including the predetermined reproduction format, and the read-only area is located on an inner portion of the optical disk, while the rewritable area is located on an outer portion of the optical disk.

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 method for reproducing write-once information from an optical disk. The disk includes a disk substrate and a recording layer on the disk substrate, the recording layer including a magnetic film with a magnetic anisotropy in a direction perpendicular to a surface of the magnetic film. Write-once information formed by first recording areas and second recording areas is stored in a pre-determined portion of said recording layer, the first and second recording areas having different magnetic anisotropies in a direction perpendicular to a surface of the magnetic film. The method includes irradiating linearly polarized laser light onto said pre-determined portion, and detecting a rotational change in a polarization orientation of light reflected from the optical disk or light transmitted through the optical disk, the rotational change being caused depending on which of the first recording area and the second recording area is irradiated with the linearly polarized laser light.

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: Address groups are composed of two of address blocks 16, 17, 18, and 19, where the address blocks 16, 17, 18, and 19 are disposed in a sector address region 5 and include identifiable information of address numbers 13 and overlapping sequential numbers 14. The address groups are disposed so that each group is alternately shifted from a track center 2 toward the inner periphery side or the outer periphery side, by a width substantially equal to half the track pitch, along the radius direction.

Abstract: Address groups are composed of two of address blocks 16, 17, 18, and 19, where the address blocks 16, 17, 18, and 19 are disposed in a sector address region 5 and include identifiable information of address numbers 13 and overlapping sequential numbers 14. The address groups are disposed so that each group is alternately shifted from a track center 2 toward the inner periphery side or the outer periphery side, by a width substantially equal to half the track pitch, along the radius direction.

Abstract: The optical disk of this invention includes a read-only area in which a plurality of read-only tracks are formed and a rewritable area in which a plurality of rewritable tracks are formed, wherein each of the plurality of read-only tracks is divided into a plurality of first sectors, a signal is prerecorded in at least one of the plurality of first sectors under a predetermined reproduction format, each of the plurality of rewritable tracks is divided into a plurality of second sectors, a signal is recordable in at least one of the plurality of second sectors under a predetermined recording format including the predetermined reproduction format, and the read-only area is located on an inner portion of the optical disk, while the rewritable area is located on an outer portion of the optical disk.

Abstract: Address groups are composed of two of address blocks 16, 17, 18, and 19, where the address blocks 16, 17, 18, and 19 are disposed in a sector address region 5 and include identifiable information of address numbers 13 and overlapping sequential numbers 14. The address groups are disposed so that each group is alternately shifted from a track center 2 toward the inner periphery side or the outer periphery side, by a width substantially equal to half the track pitch, along the radius direction.

Abstract: The optical disk of this invention includes a read-only area in which a plurality of read-only tracks are formed and a rewritable area in which a plurality of rewritable tracks are formed, wherein each of the plurality of read-only tracks is divided into a plurality of first sectors, a signal is prerecorded in at least one of the plurality of first sectors under a predetermined reproduction format, each of the plurality of rewritable tracks is divided into a plurality of second sectors, a signal is recordable in at least one of the plurality of second sectors under a predetermined recording format including the predetermined reproduction format, and the read-only area is located on an inner portion of the optical disk, while the rewritable area is located on an outer portion of the optical disk.

Abstract: A device for reading encrypted information from an optical disk having first and second recording areas, which device can read encrypted information recorded by a first modulation method in the first recording area, read disk identification information recorded by a second modulation method in the second recording area, and decrypt the encrypted information using both a decipher key and disk identification information unique to the optical disk.

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: Address groups are composed of two of address blocks 16, 17, 18, and 19, where the address blocks 16, 17, 18, and 19 are disposed in a sector address region 5 and include identifiable information of address numbers 13 and overlapping sequential numbers 14. The address groups are disposed so that each group is alternately shifted from a track center 2 toward the inner periphery side or the outer periphery side, by a width substantially equal to half the track pitch, along the radius direction.

Abstract: An optical disc having both rewritable area and read-only area is disclosed. The rewritable area has a single spiral pattern of start track land at a leading edge, and a single spiral pattern of end track land at a trailing edge, whereby portions of the physical address area PID deviated approximately Pa/2 from the track of the rewritable area are being intruded into the start track land and the end track land.