Abstract: An optical recording method for recording information by irradiating an optical disc medium with a modulated write pulse train of laser light variable over a plurality of power levels such that a plurality of marks are formed on the optical disc medium, edge positions of each of the marks and a space between adjacent two of the marks being utilized for recording of the information.

Abstract: A most probable path is selected from a number n (where n?2) of paths of state transitions occurring from a first state Sk?j (where k?3 and j?2) at a time k?j into a second state Sk at a time k. The method includes the steps of detecting predetermined combinations of the first and second states Sk?j and Sk defining the n probable paths in a predetermined period j between the times k?j and k, and evaluating the reliability of a read signal, decoded in the period j, by |Pa?Pb|. Pa and Pb indicate the probabilities of state transition of first and second state transition paths in the period j. The first and second state transition paths are estimated to be the most probable and the second most probable, respectively, among the n probable paths defined by the combinations detected.

Abstract: A recording medium comprising a recording area, the recording area includes a first area and a second area, the first area includes a frame area, the frame area includes an area in which a second synchronization code sequence and at least a portion of data are to be recorded, and the second area includes an area of linking frames in which a third synchronization code sequence and a fourth synchronization code sequence are to be recorded.

Abstract: An information recording medium, comprising N number (N is an integer fulfilling N?3) of information layers on which information is recordable, and allowing information to be recorded on each of the information layers and allowing information recorded on each of the information layers to be reproduced by being irradiated with laser light. The N number of information layers include an N'th information layer, an (N?1)th information layer, an (N?2)th information layer, . . . a second information layer and a first information layer sequentially located from a laser light incidence side. A reflectance of the N'th information layer is RN, and a reflectance of an M'th information layer (M refers to every integer fulfilling N>M?1) is RM.

Abstract: An information recording medium (9) comprises an information layer (9a) in which concavo-convex marks are formed, and a recording layer (13), contained within the information layer (9a), in which added marks are formed by optical properties changing through laser irradiation, and that contains Te, O, and M (where M is at least one element selected from a group consisting of Pd, Au, Pt, Ag, Cu, and Ni). In this information recording medium (9), a pre-laser irradiation reflectance Ra and a post laser irradiation reflectance Rb fulfill 1.0<Rb/Ra<1.1.

Abstract: An optical recording method includes the steps of: encoding record data to generate encoded data which is a combination of marks and spaces; classifying the encoded data according to a combination of a mark length of the mark, a space length of a first space that immediately precedes the mark, and a space length of a second space that immediately succeeds the mark; generating a write pulse train for forming the mark, in which at least one of a leading end edge position, a trailing end edge position and a pulse width of the write pulse train is changed according to a classification result; and irradiating the optical disc medium with the write pulse train generated to form the plurality of marks on the optical disc medium.

Abstract: According to a method of the present invention for recording data on an optical disk, a recording pulse corresponding to a long mark includes a combination of a leading pulse and a subsequent intermediate pulse. Further, a level of the leading pulse indicates a first recording power, and a level of the intermediate pulse indicates a second recording power. When an optical disk includes a plurality of recording layers, a ratio of the second recording power to the first recording power is determined for each recording layer. When the recording speed is variable, the ratio of the second recording power to the first recording power is determined for each recording speed.

Abstract: An optical recording method for recording information by irradiating an optical disc medium with a modulated write pulse train of laser light variable over a plurality of power levels such that a plurality of marks are formed on the optical disc medium, edge positions of each of the marks and a space between adjacent two of the marks being utilized for recording of the information.

Abstract: In an optical information recording medium of the present invention, at least one information layer provided on a transparent substrate includes a protective layer and a write-once recording layer that are disposed in this order from the transparent substrate side. The recording layer contains at least one selected from Cr—O, Zn—O, Ga—O, In—O, Sn—O, Sb—O, Bi—O, and Te—O. The protective layer contains at least one selected from Cr—O, Zn—O, Ga—O, In—O, Sn—O, Sb—O, Bi—O, and Te—O. When the total amount of all the atoms other than oxygen atoms contained in the protective layer is taken as 100 atom %, the total amount of atoms of Cr, Zn, Ga, In, Sn, Sb, Bi, and Te in the protective layer is at least 70 atom %.

Abstract: An optical disc drive apparatus (100) of the present invention rotates an optical disc (1) at a predetermined rotation speed using a motor (2). An optical pickup (3) irradiates the optical disc (1) with a laser beam (5) emitted from an internal semiconductor laser (4) included therein, and obtains a reproduction signal (7) based on a laser beam reflected from the optical disc (1). A laser driving unit (8) controls a driving current (9) of the semiconductor laser (4) to a predetermined level, and superimposes a high-frequency current (11) having a predetermined level on the driving current (9). In a high-speed reproduction mode, a control unit (12) sets the rotation speed of the optical disc (1) higher, the power of the laser beam (5) irradiating the optical disc (1) higher, and the level of the high-frequency current (11) lower than in a normal reproduction mode.

Abstract: According to a method of the present invention for recording data on an optical disk, a recording pulse corresponding to a long mark includes a combination of a leading pulse and a subsequent intermediate pulse. Further, a level of the leading pulse indicates a first recording power, and a level of the intermediate pulse indicates a second recording power. When an optical disk includes a plurality of recording layers, a ratio of the second recording power to the first recording power is determined for each recording layer. When the recording speed is variable, the ratio of the second recording power to the first recording power is determined for each recording speed.

Abstract: A recording medium comprising a recording area, the recording area includes a first area and a second area, the first area includes a frame area, the frame area includes an area in which a second synchronization code sequence and at least a portion of data are to be recorded, and the second area includes an area of linking frames in which a third synchronization code sequence and a fourth synchronization code sequence are to be recorded.

Abstract: An optical disc writing condition determining method according to the present invention includes the steps of: performing a first test write operation at a low speed on an inner test track; setting condition A for performing a write operation at the low speed on the inner test track based on a result of the first test write operation; performing a second test write operation at the low speed on an outer test track; setting condition B for performing a write operation at the low speed on the outer test track based on a result of the second test write operation; performing a third test write operation at a high speed on the outer test track; setting condition C for performing a write operation at the high speed on the outer test track based on a result of the third test write operation; and calculating either a difference between the conditions A and B or a ratio of the condition B to the condition A and modifying the condition C based on the difference or the ratio, thereby determining writing condition D for

Abstract: According to a method of the present invention for recording data on an optical disk, a recording pulse corresponding to a long mark includes a combination of a leading pulse and a subsequent intermediate pulse. Further, a level of the leading pulse indicates a first recording power, and a level of the intermediate pulse indicates a second recording power. When an optical disk includes a plurality of recording layers, a ratio of the second recording power to the first recording power is determined for each recording layer. When the recording speed is variable, the ratio of the second recording power to the first recording power is determined for each recording speed.

Abstract: A method for writing a signal on an optical disk is disclosed. The optical disk comprises a track groove on a recording surface thereof, on which information is recorded along the track groove on a block-by-block basis each said block having a predetermined length and where an identification mark indicating the beginning of each said block, has been formed on the track groove. Writing is started before the identification mark, located at the beginning of at least one block on which the signal should be written, is reached and writing is ended after the identification mark located at the end of the at least one block on which the signal should be written has been passed.

Abstract: An optical information recording reproducing apparatus precisely decides at least the time width of a recording pulse sequence so as to obtain a preferable signal quality by controlling a recording power and a pulse time width during a high-speed write. The apparatus includes: modulation instrument for generating a test pattern containing at least a first recording mark length; recording pulse sequence conversion instrument for converting the test pattern into a recording pulse sequence containing test recording pulses having different time widths corresponding to at least the first recording mark length; beam irradiation instrument; reproduced signal processing instrument for holding as a first signal index characteristic, the relation between a first signal index acquired according to the reproduced signal obtained from a predetermined area and the recording power; and recording condition calculation instrument for obtaining a desired time width of a recording pulse of the first recording mark length.

Abstract: An optical disc verification method according to the present invention includes the steps of: writing data on first, second and third radial locations on an optical disc at a writing speed V1 and reading the data written there, thereby measuring read signal quality index values A, B and C, where the second radial location is inside of the first radial location and the third radial location is inside of the second radial location; writing data on the first and second radial locations at a writing speed V2, which is higher than V1, and reading the data written there, thereby measuring read signal quality index values D and E; and correcting the signal quality index value C with the difference between the signal quality index values B and E, thereby calculating a signal quality index value F that would be obtained if data is written on, and then read from, the third radial location at the speed V2.

Abstract: A recording medium comprising a recording area, the recording area includes a first area and a second area, the first area includes a frame area, the frame area includes an area in which a second synchronization code sequence and at least a portion of data are to be recorded, and the second area includes an area in which a third synchronization code sequence and a fourth synchronization code sequence are to be recorded.

Abstract: A data recording method according to the present invention is a method for recording data as edge position information, including marks and spaces of multiple different lengths, on a storage medium by irradiating the storage medium with a pulsed energy beam. The method includes the steps of: (A) generating a write code sequence based on the data to be recorded; (B) determining a write pulse waveform, defining the power modulation of the energy beam, according to the code lengths of respective codes included in the write code sequence; and (C) modulating the power of the energy beam based on the write pulse waveform.

Abstract: An information recording medium according to the present invention includes three or more information recording layers. Each of the plurality of information recording layers includes a test recording area usable for adjusting a recording condition. One of the plurality of information recording layers includes a reproduction-only management data area in which management data usable for managing the information recording medium is pre-recorded. One information recording layer includes a recordable management data area in which management data usable for managing the information recording medium is newly writable. Each of the other two or more information recording layers among the plurality of information recording layers includes a test recording area at a radial position overlapping the radial position of a part of the reproduction-only management data area. In the one recording layer including the recordable management data area, the recordable management data area is provided at two positions, i.e.