Abstract: An apparatus of the present invention is an optical disk apparatus for irradiating a track on an information carrier on which information is recorded with a light beam so as to reproduce information from the track. The optical disk apparatus includes: a tracking error detector for detecting a tracking error signal representing a displacement between the light beam and the track; a fine movement section for moving the light beam in a substantially radial direction of the information carrier; a coarse movement section for moving the fine movement section in the substantially radial direction of the information carrier; a tracking controller for controlling the fine movement section and the coarse movement section based on the tracking error signal detected by the tracking error detector so that the light beam is positioned along the track; and an eccentricity detector for detecting an amount of eccentricity of the track on the information carrier.

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: 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: An optical disk apparatus comprising a device for moving a focal point of a light beam for reproducing information recorded on an information face of a disk, in the direction perpendicular to the information face; a device for detecting a reflected light from the disk; and a device for discriminating whether the disk set in the apparatus is a disk having a thick base substrate or a disk having a thin base substrate. In this apparatus, a maximum value AS1Lmax of an output signal from the reflected light detecting device and a maximum value ENVmax of an amplitude of an information reproducing signal are detected while driving the focal point moving device so that the focal point passes through the information face, and the discriminating device discriminates whether the disk set in the apparatus is a disk having a thick base substrate or a disk having a thin base substrate, on the basis of the ratio of ENVmax to AS1Lmax.

Abstract: A device for reading encrypted information recorded on an optical disk having first and second recording areas, the device can read disk identification information recorded in the second recording area, select a specific decipher key among multiple decipher keys, and decrypt encrypted information from the optical disk using both the disk identification information unique to that optical disk and the specific decipher key.

Abstract: A speed profile constituting the target speed for the next drive process during searching is generated by target speed generating section 140 and tracking actuator 132 is driven using the error signal in regard to the speed of movement of the light beam calculated by movement speed detection section 141 from a pulse signal obtained by converting the TE signal to binary form. Also linear motor 139 is driven using the difference signal obtained from the target speed and the speed of movement. Tracking actuator 132 is controlled so as to suppress swinging of focusing lens 107 during searching and linear motor 139 moves, during searching, under tracking control to a target speed.

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 object of the present invention is to realize a stable control and a stable signal reproduction in an optical disc device. When a head unit (110) is shifted in a radial direction or a reproduction speed is varied, a reproduction speed is detected based on a radial position at which the head unit is located and the number of rotaions of a motor (111), and settings of a focusing gain, a tracking gain, an amplification factor of an equalizer circuit (130), a band-limited frequency, a loop gain of a PLL circuit (131) and a divide ratio are varied based on said reproduction speed. Further, an accurate detection of an out of focus operation can be executed by using either one signal of a reflected-light quantity, an RF signal amplitude and a drive of a focusing actuator, or combined signals thereof. Thereby, a stable control and signal reproduction can be provided.

Abstract: An optical disk apparatus comprising a device for moving a focal point of a light beam for reproducing information recorded on an information face of a disk, in the direction perpendicular to the information face; a device for detecting a reflected light from the disk; and a device for discriminating whether the disk set in the apparatus is a disk having a thick base substrate or a disk having a thin base substrate. In this apparatus, a maximum value AS1Lmax of an output signal from the reflected light detecting device and a maximum value ENVmax of an amplitude of an information reproducing signal are detected while driving the focal point moving device so that the focal point passes through the information face, and the discriminating device discriminates whether the disk set in the apparatus is a disk having a thick base substrate or a disk having a thin base substrate, on the basis of the ratio of ENVmax to AS1Lmax.

Abstract: The optical recording medium of this invention 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 0.56 mm or more, the thickness of the adhesive layer is 30 &mgr;m or more, and the total thickness of the first substrate and the adhesive layer is 0.68 mm or less.

Abstract: A device for recording information on an optical disk having first and second recording areas, which device can record information using a first modulation method into a first recording area, read disk identification information recorded by a second modulation method in a second recording area, encrypt information using both a cipher key and disk identification information unique to the optical disk, and permit recording of such encrypted information after confirming the content of a recording permission code in an input signal for recording.

Abstract: An optical disk apparatus comprises a focusing means for focusing a light beam on a recording medium having first and second information faces; means for moving a focal point of the light beam in a direction substantially perpendicular to the information faces of the recording medium; means for detecting a reflected light from the recording medium; means for detecting a focus condition of the light beam on the basis of an output signal from the reflected light detecting means; a focus control means for driving the focal point moving means on the basis of an output signal from the focus condition detecting means, and controlling the light beam so that the focus condition of the light beam becomes a prescribed focus condition; and a focus jumping means for moving the focal point of the light beam from the first information face to the second information face by driving the focal point moving means.

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 disk apparatus for reproducing information from plural types of information carriers or for recording information to plural types of information carriers, has two or more light sources with different wavelengths, a converging part for converging a light beam emitted from each of the light sources on said information carrier, a movement part for moving the converged spot of the light beam converged by the converging part in a direction substantially perpendicular to the surface of the information carrier, a convergence condition detection part for outputting a signal corresponding to the convergence condition of the light beam on the information carrier, an amplitude detection part for measuring the amplitude of the signal of the convergence condition detection part, and a focus control part for driving the movement part in accordance with the output signal of the convergence condition detection part and for performing control so that the convergence condition of the light beam on the information ca

Abstract: The optical recording medium of this invention 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 0.56 mm or more, the thickness of the adhesive layer is 30 &mgr;m or more, and the total thickness of the first substrate and the adhesive layer is 0.68 mm or less.

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: An optical disk and a method for storing write-once information usable for preventing the illegal copies. The optical disk comprises a disk substrate, and a recording layer having a magnetic film disposed on the disk substrate. The optical disk stores write-once information formed by first recording areas and second recording areas and the write-once information being different for each disk. The second recording areas are formed as a plurality of stripe-shaped marks that are oblong in a radial direction of the disk by irradiating laser light based on a modulation signal of the write-once information in the pre-determined portion of the recording layer, in a manner that a magnetic anisotropy in a direction perpendicular to a surface of the second recording areas is smaller than a magnetic anisotropy in a direction perpendicular to a surface of the first recording areas.

Abstract: A disk rotation control apparatus includes a spindle motor for rotating a disk, a rotational speed detecting device for detecting the rotational speed of the spindle motor, a signal generating device for generating an acceleration signal that accelerates the rotation of the spindle motor and a deceleration signal that decelerates the rotation of the spindle motor. A storage device for rotating the spindle motor with an acceleration signal generated by the signal generating device, measures a rise time required to reach a prescribed rotational speed &ohgr;1 while detecting the rotational speed of the spindle motor by the rotational speed detecting device, and stores the measured rise time. A control device for decides a time to generate the deceleration signal in the signal generating device on the basis of the rise time stored in the storage device, and stops the rotation of the spindle motor by applying the deceleration signal to the spindle motor.

Abstract: A speed profile constituting the target speed for the next drive process during searching is generated by target speed generating section 140 and tracking actuator 132 is driven using the error signal in regard to the speed of movement of the light beam calculated by movement speed detection section 141 from a pulse signal obtained by converting the TE signal to binary form. Also linear motor 139 is driven using the difference signal obtained from the target speed and the speed of movement. Tracking actuator 132 is controlled so as to suppress swinging of focusing lens 107 during searching and linear motor 139 moves, during searching, under tracking control to a target speed.