Abstract: Disclosed is an information recording medium which, when inserted into a recording/reproducing device, can be run in an updated state intended by a disc supplier since a recordable layer can be specified as a layer to be run first. For example, in an optical disc including an L1 layer which is a read-only recording layer and an L0 layer which is a recordable layer, layer specifying information for specifying the L0 layer in priority to the L1 layer is recorded as an information recording layer to be run first when the optical disc is inserted into the optical disc device which carriers out recording or reproduction of information with respect to the optical disc.

Abstract: A method and an apparatus for reading data from or writing data to an optical recording medium is described, the data being stored as marks having different lengths. Marks having a length below the limit of diffraction at a first wavelength are read or written with the first wavelength, whereas marks having a length above the limit of diffraction at the first wavelength are read or written with a second wavelength larger than the first wavelength.

Abstract: The present invention relates to a recording/reproducing device that records data on a double-sided recordable optical disk for storage and management purposes. The device includes a unit which stores a plurality of optical disks, a unit which records data onto and reproduces data from an upper side of an optical disk, a unit which records data onto and reproduces data from a lower side of an optical disk, a unit which conveys an optical disk between the disk storage unit and each recording/reproducing unit. When a request for reading data recorded on the lower side of the disk is received while the upper side is being written onto, a control unit interrupts a data recording process on the upper side, reproduces data recorded on the lower side, and after completion of reproducing the recorded data, resumes the interrupted data recording process.

Abstract: In the related art, writing of BCA data has been performed by a BCA cutter or the like after a user data area was formed. However, according to such a method, individual steps cannot help being provided for a disc manufacturing step in order to form the BCA. A burden on the disc manufacturer is large from a viewpoint of the number of disc producing steps and, further, manufacturing costs. By using a bit forming method similar to a user data area, the BCA manufacturing steps can be reduced. Specifically speaking, by devising a pit depth, a pit width, and a pit pattern, a modulation degree of a BCA portion can be further increased. A detecting method similar to that for the BCA in the related art can be applied.

Abstract: An integrated circuit is provided in an optical disc apparatus for drawing a visible image on an optical disc including a discoloration layer which is discolored by heat or light by irradiating the optical disc with laser light. The integrated circuit includes a tracking direction displacement section configured to execute, when the visible image is drawn, oscillation control to oscillate a position irradiated with the laser light in a radial direction of the optical disc, and a laser modulation section configured to change, when the visible image is drawn, an intensity of the laser light so that the higher a displacement rate of the position irradiated with the laser light in the radiation direction is, the higher the intensity of the laser light becomes.

Abstract: There is provided a metal complex that is large in degree of a change in emission intensity, the change being caused by a change in molecular structure of a ligand through a photochromic reaction. The metal complex is arranged such that a diarylethene-based photochromic molecule coordinates to a metal ion via two groups directly bonded to respective reaction site carbons and that the groups are each independently a group selected from Formula Group (1) above.

Abstract: Bandwidth is secured for a read signal transmission line by matching the characteristic impedance of the read signal transmission line with the output impedance of a photodetector of an optical pick up, while at the same time securing bandwidth for the photodetector. In an optical disc drive according to an embodiment of the present invention, each line forming a differential transmission line is divided into a plurality of lines of the same quantity, the quantity being two or more, at or near a connection point between a flexible line and the optical pick up.

Abstract: An optical recording medium including a plurality of recording layers to record/reproduce information using light with a predetermined wavelength, the information being recorded on one of the recording layers using a mark and a space, wherein a channel clock period T is provided for recording the mark on one of the recording layers. A plurality of pulses, including a last pulse arranged at an end of the pulses, are used to record the mark with length 3T, the mark being recorded with a condition that a width of the last pulse is minimum OT and maximum 1.10T, in which a first subsequent level lower than a peak power level of the last pulse is arranged next to the last pulse, and a second subsequent level lower than the peak power level but higher than the first subsequent level is arranged next to the first subsequent level.

Abstract: There is provided an optical recording method for directing a recording pulse train to an optical disc medium to form marks thereon and for recording information as information about the edge positions of said marks and the spaces between marks, the recording pulse train having been created by modulating laser light into plural power levels. The method includes: coding to-be-recorded data into coded data consisting of the combination of marks and spaces; classifying said marks within said coded data on the basis of the mark length and the preceding or succeeding space lengths of the marks; shifting the position of the second pulse edge counted from the end portion of the recording pulse train for forming said marks, depending on the result of said classification, to adjust said recording pulse train; and directing said recording pulse train to the optical disc medium to form said marks thereon.

Abstract: An information recording medium in which bottoms of a guide groove and a pit array formed on a disc substrate are allocated on a same flat plane and shaped in flat. Further, in a transition area from a pit array to a guide groove or from a guide groove to a pit array, the information recording medium is provided with an intermediate area composed of a pit array of which height changes from a height between a bottom and a side of a groove to another height between the bottom and a side of the pit array.

Abstract: To compensate for edge shifts varying largely in accordance with preceding mark lengths. Provided are a method and a recorder in which a duration of a cooling pulse in each recording pulse string to form a mark having a length of nT is determined on the basis of an edge shift amount of a front edge of a mark whose preceding mark has a length of nT, where n is an integer and T is a channel bit length.

Abstract: An optical data retrieval system configured to retrieve data from a data storage medium, including: a source of n path-entangled photons, where n is an integer of at least 2; a detector system configured to determine if n photons have been received; and a mechanism to direct photons from the source to the data storage medium and to the detector system.

Abstract: Provided is an apparatus and method for recording data on a holographic storage medium. The apparatus includes: a light a light processing unit comprising the holographic storage medium and a light modulator, and recording data on the holographic storage medium using a reference beam and a signal beam modulated by the light modulator; and a control unit controlling the light processing unit to record the data on the holographic storage medium, wherein the light modulator is arranged so that an image formed on a surface of the light modulator is shorter in a radial direction that is a scanning direction of the reference beam than in a tangential direction that is perpendicular to the radial direction.

Abstract: The present invention relates to a method and apparatus for writing data on a record carrier (1) by using a radiation beam, wherein at least one of a writing power and an asymmetry of data written on the record carrier (1) is determined and a radial error offset, applied to the radiation beam with respect to a writing track of the record carrier (1), is controlled in response to at least one of the determined writing power and the determined asymmetry. Thereby, the radial error offset can be linked to at least one of the applied writing power and the obtained asymmetry of the written data, and can thus be altered before or during writing to maintain reasonable tracking in cases where writing is done on record carriers with variable radial error offset.