摘要:
The optical disk device performs recording/reproducing of data by a predetermined recording block on the track of an optical disk. The device has a recording unit, an optical-head, and a failure detection unit. The recording unit generates a recording signal by modulating the data. The optical-head records data on the track by optical beam emission to the track according to the recording signal, and detects light reflected off the track and then generates a detection signal based on the reflected light. The failure detection unit detects an abnormal condition based on the detection signal changed from a normal condition. If the sum of duration of an abnormal condition in the recording block is equal to or greater than a first time-length, the failure detection unit determines that the recording block has a flaw.
摘要:
A device for producing a security mark on an optical data carrier includes directing means for directing a first and a second light beam onto a hologram area of the optical data carrier, wherein the first and second light beams are coherent light beams. The directing means are adapted to direct the first light beam onto the hologram area along a first direction, and the second light beam onto the hologram area along a second direction. Tilting means are provided for tilting the second direction by a predefined tilt angle with respect to the first direction.
摘要:
An optical information recording medium has a first information recording layer (20) and a second information recording layer (40) each of which includes (i) a group of pre-pits (31, 51) constituting marks (32, 52) and spaces (33, 53) and (ii) a super-resolution film (23, 43), the marks (32, 52) and the spaces (33, 53) having different lengths, an average length of a smallest mark that is smallest in length and a smallest space that is smallest in length being less than or equal to a resolution limit of a reproduction optical system for reproducing information recorded on the first information recording layer (20) and the second information recording layer (40), the group of pre-pits (31, 51) being formed so that a push-pull signal for the reproduction optical system to reproduce the information recorded by the group of pre-pits is negative in polarity. This provides an inexpensive and high-capacity multilayer optical information recording medium based on a super-resolution technology.
摘要:
A method of performing writable optical recording of a medium to form multilevel oriented nano-structures therein, comprises steps of providing a disc-shaped, writable recording medium having a planar surface; and encoding data/information in the medium by forming a plurality of multilevel nano-structured pits in the surface by scanning with a focused spot of optical energy to form at least one data track therein, including scanning the optical spot in a cross-track direction while rotating the disc about a central axis.
摘要:
The present invention provides a write-once-read-many optical recording medium comprising a substrate, a recording layer comprising any one of bismuth and an oxide of bismuth, an overcoat layer and a reflective layer in this order from a laser beam incident plane, wherein the write-once-read-many optical recording medium has a reflectivity of 35% or less when a laser is applied to the flat part of the substrate or a write-once-read-many optical recording medium comprising a substrate, an undercoat layer, a recording layer comprising any one of bismuth and an oxide of bismuth, an overcoat layer and a reflective layer in this order from a laser beam incident plane, wherein the write-once-read-many optical recording medium has a reflectivity of 35% or less when a laser is applied to the flat part of the substrate.
摘要:
An information recording medium having at least a read only area and a recording and reproducing area is composed of at least: a substrate; a recording layer formed on the substrate so as to record and reproduce information; and a light transmission layer having transparency formed on the recording layer. The information recording medium is further characterized in that a wobbling groove corresponding to the read only area and another wobbling groove corresponding to the recording and reproducing area is formed on the substrate without overlapping with each other, the recording and light transmitting layers are continuously adhered over at least two areas of the read only area and the recording and reproducing area, reflectivity of the recording layer is more than 5%, and a push-pull signal output T3 reproduced from the read only area and another push-pull signal output T4 reproduced from the recording and reproducing area before recording satisfies relations of T3≧0.1, T4≧0.1 and 1.5≧T3/T4≧0.5.
摘要:
There are provided a method and apparatus for embedding a second level code into a first level code of an optical disc by data modulation rule variation. The apparatus includes a multi-level, varying rule based modulator (199) for modulating the first level code to obtain a channel bit stream representative of the first level code and having the second level code embedded therein. The multi-level, varying rule based modulator modulates the first level code using modulation rules respectively having different statistical properties of pit-land length distributions that preserve a readability of the first level code and that are distinguishable at readout of the optical disc. The different statistical properties represent binary or multilevel data of the second level code.
摘要:
An information recording medium includes a plurality of layers for recording or reproduction of information by irradiation, wherein each of the layers includes an emboss portion and wobble portion including wobbles of a first frequency and a second frequency that is different from the first frequency. The first frequency is constant in each of the plurality of layers, and a different signal is obtained from the wobbles of the first and second frequencies in each of the plurality of layers.
摘要:
An information recording medium having at least a read only area and a recording and reproducing area is composed of at least: a substrate; a recording layer formed on the substrate so as to record and reproduce information; and a light transmission layer having transparency formed on the recording layer. The information recording medium is further characterized in that a wobbling groove corresponding to the read only area and another wobbling groove corresponding to the recording and reproducing area is formed on the substrate without overlapping with each other, the recording and light transmitting layers are continuously adhered over at least two areas of the read only area and the recording and reproducing area, reflectivity of the recording layer is more than 5%, and a push-pull signal output T3 reproduced from the read only area and another push-pull signal output T4 reproduced from the recording and reproducing area before recording satisfies relations of T3≧0.1, T4≧0.1 and 1.5≧T3/T4≧0.5.
摘要:
A multi-level information reproducing method for reproducing from a recording medium on which marks having detection signal levels different according to multi-level information are recorded in areas virtually divided uniformly, comprising the steps of: a) obtaining a reproduced signal from a series of patterns of multi-level information indicating an average level of intersymbol interference components to adjacent areas generated from marks according to all the multi-level information; and b) optimizing frequency characteristics of a reproducing part with respect to the reproduced signal.