Abstract: An information recording and reproducing device has a recording section, a reproducing section, and a deterioration detection processor which detects deterioration of a signal quality of information recorded in a recording medium.

Abstract: An information recording and reproducing device has a recording section, a reproducing section, and a deterioration detection processor which detects deterioration of a signal quality of information recorded in a recording medium.

Abstract: There are provided an optical head and an optical information device capable of downsizing the optical head, and capable of improving the qualities of a focus error signal, a tracking error signal, and a reproduction signal. A light detector (120) includes a light-receiving unit (121) for receiving a reflected light beam from an optical disc, and a package (125) for covering the light-receiving unit (121). The package (125) has a plurality of light guides (124) formed on a light-receiving surface on the light beam incident side of the light-receiving unit (121), and for guiding a reflected light beam to the light-receiving unit (121), and a light shield (114) for shielding a region except for a plurality of the light guides (124) from light.

Abstract: A storage device according to the present invention constructs a RAID structure using a plurality of detachable recording mediums. When a first drive device fails to reproduce data from a recording medium, a transport device transports the recording medium to a second drive device different from the first drive device which failed to reproduce the data, and the second drive device attempts to reproduce the data from the recording medium, the data reproduction from which failed. Owing to this, even when faults of a number exceeding the number of faults correctable by the RAID structure occur, the probability that the data is recovered can be improved.

Abstract: There are provided an optical head and an optical information device capable of downsizing the optical head, and capable of improving the qualities of a focus error signal, a tracking error signal, and a reproduction signal. A light detector (120) includes a light-receiving unit (121) for receiving a reflected light beam from an optical disc, and a package (125) for covering the light-receiving unit (121). The package (125) has a plurality of light guides (124) formed on a light-receiving surface on the light beam incident side of the light-receiving unit (121), and for guiding a reflected light beam to the light-receiving unit (121), and a light shield (114) for shielding a region except for a plurality of the light guides (124) from light.

Abstract: An information recording medium according to the present invention includes at least three information recording layers. If the readout power of a laser beam in reading information from an information recording layer L(n) is identified by Pw(n), and if the readout power of the laser beam in reading information from an information recording layer L(n+a) is identified by Pw(n+a), then a base thickness between the information recording layers is determined so that the intensity of the light when the information recording layer L(n+a) is irradiated with a laser beam having the readout power Pw(n) becomes equal to or lower than that of the light when the information recording layer L(n+a) is irradiated with a laser beam having the readout power Pw(n+a).

Abstract: An information recording medium according to the present invention includes at least three information recording layers. If the readout power of a laser beam in reading information from an information recording layer L(n) is identified by Pw(n), and if the readout power of the laser beam in reading information from an information recording layer L(n+a) is identified by Pw(n+a), then a base thickness between the information recording layers is determined so that the intensity of the light when the information recording layer L(n+a) is irradiated with a laser beam having the readout power Pw(n) becomes equal to or lower than that of the light when the information recording layer L(n+a) is irradiated with a laser beam having the readout power Pw(n+a).

Abstract: An information recording medium according to the present invention includes at least three information recording layers. If the readout power of a laser beam in reading information from an information recording layer L(n) is identified by Pw(n), and if the readout power of the laser beam in reading information from an information recording layer L(n+a) is identified by Pw(n+a), then a base thickness between the information recording layers is determined so that the intensity of the light when the information recording layer L(n+a) is irradiated with a laser beam having the readout power Pw(n) becomes equal to or lower than that of the light when the information recording layer L(n+a) is irradiated with a laser beam having the readout power Pw(n+a).

Abstract: An information recording medium according to the present invention includes at least three information recording layers. If the readout power of a laser beam in reading information from an information recording layer L(n) is identified by Pw(n), and if the readout power of the laser beam in reading information from an information recording layer L(n+a) is identified by Pw(n+a), then a base thickness between the information recording layers is determined so that the intensity of the light when the information recording layer L(n+a) is irradiated with a laser beam having the readout power Pw(n) becomes equal to or lower than that of the light when the information recording layer L(n+a) is irradiated with a laser beam having the readout power Pw(n+a).

Abstract: A method for reading address information from an optical disc with a wobbled track groove includes the steps of: obtaining a sine wave address signal, a first address signal representing a first groove region with sine wave wobbled portions and an inverted phase portion, and a second address signal representing a second groove region with steep inward or outward displacements; multiplying a first reference signal, being phase-locked to, and having the same frequency as, the sine wave address signal, and the first address signal together to obtain a first multiplied signal; multiplying a second reference signal, being phase-locked to, and having a frequency twice as high as, the sine wave address signal, and the second address signal together to obtain a second multiplied signal; integrating the first, multiplied signal and the second multiplied signal separately to obtain a first integral and a second integral, respectively; and adding the first and second integrals together.

Abstract: At the time of heterodyne detection, information is reproduced constantly in the optimum condition. A method reproduces information recording medium including a reference wobble block which has a first wobble pattern representing a first information content; and an information wobble block which follows the reference wobble block and which has at least one of the first wobble pattern and a second wobble pattern representing a second information and different from the first wobble pattern. The method includes reading the reference wobble block and the information wobble block; comparing a wobble pattern read from the information wobble block with the first wobble pattern of the reference wobble block; judging that information recorded in the information wobble block is the first information or the second information according to the wobble pattern read from the information wobble block; and outputting one of the first and the second information based on the judging result.

Abstract: An information storage medium 100 according to the present invention includes a track 10 that wobbles in a predetermined period and a plurality of pre-pits 21 and 22, which are arranged adjacent to the track. The track has a plurality of frame units 11 and 12. At least one of the pre-pits 21 and 22 is allocated to each of the frame units 11 and 12. Each of the frame units 11 and 12 has a first wobble shape 111, of which the falling portion is sloped more steeply than its rising portion, and/or a second wobble shape 112, of which the rising portion is sloped more steeply than its falling portion. The first wobble shape 111 represents a first type of information and the second wobble shape 112 represents a second type of information. The first and second types of information are different from each other.

Abstract: An apparatus for reproducing information that has been digitally recorded on a storage medium includes first and second waveform equalizers. The first waveform equalizer equalizes a read signal, corresponding to the information read out from the storage medium, thereby outputting a first equalized signal. The second waveform equalizer has an equalization characteristic different from that of the first waveform equalizer, outputs a second equalized signal and is selectively used to extract a read clock signal.

Abstract: An optical disc apparatus is provided for accessing an optical disc having at least one track, in which at least one prepit is provided in the at least one track. The apparatus comprises a light irradiation section for irradiating the at least one track with light, a first signal generating section for detecting light reflected from the at least one track, and based on the reflected light, generating a first signal including a prepit signal indicating the at least one prepit, a second signal generating section for removing a signal component impeding detection of the prepit signal from the first signal to generate a second signal, and a prepit detecting section for detecting the at least one prepit based on at least one of the first signal and the second signal.

Abstract: A method for reading address information from an optical disc with a wobbled track groove includes the steps of: obtaining a sine wave address signal, a first address signal representing a first groove region with sine wave wobbled portions and an inverted phase portion, and a second address signal representing a second groove region with steep inward or outward displacements; multiplying a first reference signal, being phase-locked to, and having the same frequency as, the sine wave address signal, and the first address signal together to obtain a first multiplied signal; multiplying a second reference signal, being phase-locked to, and having a frequency twice as high as, the sine wave address signal, and the second address signal together to obtain a second multiplied signal; integrating the first and the first address signal 405, the second address signal 406 second multiplied signals separately to obtain a first integral and a second integral, respectively; and adding the first and second integrals toget

Abstract: At the time of heterodyne detection, information is reproduced constantly in the optimum condition. A method reproduces information recording medium including a reference wobble block which has a first wobble pattern representing a first information content; and an information wobble block which follows the reference wobble block and which has at least one of the first wobble pattern and a second wobble pattern representing a second information and different from the first wobble pattern. The method includes reading the reference wobble block and the information wobble block; comparing a wobble pattern read from the information wobble block with the first wobble pattern of the reference wobble block; judging that information recorded in the information wobble block is the first information or the second information according to the wobble pattern read from the information wobble block; and outputting one of the first and the second information based on the judging result.

Abstract: An apparatus for reproducing information that has been digitally recorded on a storage medium includes first and second waveform equalizers. The first waveform equalizer equalizes a read signal, corresponding to the information read out from the storage medium, thereby outputting a first equalized signal. The second waveform equalizer has an equalization characteristic different from that of the first waveform equalizer, outputs a second equalized signal and is selectively used to extract a read clock signal.