摘要:
An optical disc (100) from which a plurality of pieces of information recorded along a track (9) by irradiating light that moves above the track relatively are reproduced in parallel. The optical disc has a disc substrate (1), and a recording layer (2) formed thereon. On the recording layer, a track is defined concentrically and two pit rows for carrying the plurality of pieces of information independently from each other are arranged along the track on the opposite sides thereof. At a specific position where the two pit rows are in a predetermined mutual relation and the plurality of pieces of information read out by irradiating light cannot be distinguished, at least one of two pit rows is shifted by a predetermined distance in the radial direction of the disc substrate by having the track as reference. Consequently, recording capacity can be increased relatively easily.
摘要:
An information recording/reproducing device diffracts laser light into main- and sub-beams, irradiates evanescent light in relation to the main beam by an evanescent light generating element to a track where a recording pit provided on a recording surface of a recording medium is formed and evanescent light in relation to the sub-beam to be separated to a track where no recording pit provided on the recording surface of the recording medium is formed. A moving element moves the evanescent light generating element to change a gap with the recording surface. Return light in relation to the sub- and main-beam are received by sub- and main-light receiving elements, respectively. A control element controls the moving element so as to make the gap become a predetermined target value in accordance with a gap error signal containing a signal indicative of an amount of the return light in relation to the received sub-beam.
摘要:
An optical disc discriminating system comprises: a tracking error signal generating means adapted to generate a tracking error signal whose amplitude level varies with a groove depth of information tracks on an optical disc; a tracking servo means for directing a laser beam along an information track on the optical disc in accordance with the tracking error signal; a comparator adapted to compare the amplitude level of the tracking error signal supplied from the tracking error signal generating means with a reference level, with a tracking servo loop of the tracking servo means in an opened condition; a discriminating means adapted to discriminate the first and second groups of optical discs in accordance with a result from the comparator.
摘要:
An apparatus (C) manufactures an information record medium (DK), which has a track (G, L), on which information is optically recorded. The apparatus is provided with: a track forming device (40, 43, 50) for forming the track; and a transition portion forming device (40, 43, 50) for forming a transition portion (MG) for transiting an irradiation position (SP) of a light beam (LG, LL), which is used for illegally copying the information on the formed track, from an irradiation track (G2), which is irradiated by the light beam, to an adjacent track (G1), which is adjacent to the irradiation track and on which the information is recorded before the information is recorded on the irradiation track, such that the formed transition portion is continuous with the formed track.
摘要:
In an information recording medium, positions of pits are modulated in a direction intersecting a direction of reading of pits, so that a predetermined information is recorded. In this information recording medium, the whole of the predetermined information or a part of the predetermined information is randomized through the used of spread spectrum.
摘要:
In an information recording medium, positions of pits are modulated in a direction intersecting a direction of reading of pits, so that a predetermined information is recorded. In this information recording medium, the whole of the predetermined information or a part of the predetermined information is randomized through the used of spread spectrum.
摘要:
A dye record disc has a disc shape substrate having a track-forming surface divided into a read-only area and a recordable area. A reproducing track is formed on the track-forming surface in the read-only area, and has a plurality of pits, each of the pits comprising a dye material, and having a shape corresponding to the reproducing information. A recording/reproducing track is formed on the track-forming surface in the recordable area, and extends continuously, the recording/reproducing track comprising the same dye material as each of the pits. The information reproducing apparatus includes an initial light emitting device for emitting an initial light beam to all of the pits before reproduction, in order to change reflectance of all of the pits; a reproducing light emitting device for emitting a reproducing light to each of the pits; a receiving device for receiving reflected light of the reproducing light reflected by the reproducing track, and generating a receiving signal corresponding to the received reflective light; and a reproducing device for reproducing the reproducing information on the basis of the receiving signal.
摘要:
A dye record disc has a disc shape substrate having a track-forming surface divided into a read-only area and a recordable area. A reproducing track is formed on the track-forming surface in the read-only area, and has a plurality of pits, each of the pits comprising a dye material, and having a shape corresponding to the reproducing information. A recording/reproducing track is formed on the track-forming surface in the recordable area, and extends continuously, the recording/reproducing track comprising the same dye material as each of the pits. The information reproducing apparatus includes an initial light emitting device for emitting an initial light beam to all of the pits before reproduction, in order to change reflectance of all of the pits; a reproducing light emitting device for emitting a reproducing light to each of the pits; a receiving device for receiving reflected light of the reproducing light reflected by the reproducing track, and generating a receiving signal corresponding to the received reflective light; and a reproducing device for reproducing the reproducing information on the basis of the receiving signal.
摘要:
A power calibration area is provided for obtaining an optimum recording power and a first information recording area is provided after the power calibration area. A test recording area is formed after the first information recording area for obtaining an optimum recording power for recording information in a next information recording area.
摘要:
An information recording medium is provided with a wobbled track, wherein at least a part of the track is subjected to wobbling based on a wobble signal in which at least a part of recording information is randomized. Each track is wobbled at a randomized frequency, so that a frequency of a wobbling signal obtained from the wobbled track is randomized. As a result, the influence of crosstalk between adjacent track is reduced.