Abstract: An optical disk medium includes a track groove thereon. On the optical disk medium, information is recorded along the track groove on a block unit basis. The block unit has a predetermined length. The block unit having the predetermined length includes a number of sub-blocks that are arranged along the groove. A sub-block mark is provided within each of the sub-blocks and used to identify the sub-block.

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: An optical disc medium comprises a track groove, along which main information is recorded. The track groove is divided into a plurality of blocks. The plurality of blocks each include a plurality of frames. The plurality of frames each include one shape of wobbles indicating sub information, among a plurality of prescribed shapes of wobbles. The plurality of blocks each have address information. The address information is represented by a string of at least one piece of sub information represented by the shape of wobbles of at least one of the plurality of frames.

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: An optical disc medium comprises a track groove, along which main information is recorded. The track groove is divided into a plurality of blocks. The plurality of blocks each include a plurality of frames. The plurality of frames each include one shape of wobbles indicating sub information, among a plurality of prescribed shapes of wobbles. The plurality of blocks each have address information. The address information is represented by a string of at least one piece of sub information represented by the shape of wobbles of at least one of the plurality of frames.

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 apparatus for reading subdivided information from an optical disk, which comprises a track groove and on which information is recorded along the track groove is disclosed. The apparatus includes an optical head, which irradiates the optical disk with light and generates an electric signal responsive to part of the light that has been reflected from the optical disk, read signal processing means for generating a wobble signal which has an amplitude changing with the wobble pattern from the electric signal, rise value acquiring means for sampling and holding an absolute gradient value of the wobble signal when the signal rises, fall value acquiring means for sampling and holding an absolute gradient value of the wobble signal when the signal falls, and subdivided information detecting means for determining the subdivided information by majority by comparing the values held by the rise and fall value acquiring means with each other.

Abstract: In an information recording medium including a substrate and an information layer having a recording layer, on and from which information is recorded and reproduced by laser beam application, the recording layer is made from a Te—O-MA-MB material consisting of Te, O, MA (wherein MA is at least one element selected from Au and Pd) and MB (wherein MB is at least one element selected from Ag, Cu and Ni) with a content of Te of 10 atom % to 50 atom %, the content of O of 40 atom % to 70 atom %, the content of MA of 3 atom % to 15 atom %, and the content of MB of 3 atom % to 15 atom %. This constitution provides a low-cost information recording medium which enables high-density recording and stable reproduction of recorded data for a long period of term.

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: 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: An optical disk includes a groove and a land. Data is recorded on either the land or the groove. A pitch of the groove and a pitch of the land are 0.32 ?m or more. The optical disk has a data efficiency of 80% or more by adopting a format in which other types of user data are added to every plural user data sets. The data efficiency is defined by a ratio of a user data capacity that can be used by a user to a total data capacity of the optical disk.

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: 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: 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: 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 its internal semiconductor laser (4), 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: 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. 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 partially overlapping the radial position of the management data area.

Abstract: The present invention has an object of providing an optical information recording medium including three or more information layers, which allows information to be reproduced from all the information layers at high quality, and a method for reproducing information from such an information recording medium. The reflectance of a third information layer 43 is made higher than that of each of a second information layer 42 and a first information layer 41. Thus, the upper limit reproduction power of laser light 31 directed to the third information layer 43 can be made lower than that of the laser light 31 directed to each of the second information layer 42 and the first information layer 41. For reproduction, the reproduction power of each information layer is equal to or lower than the upper limit reproduction power, and a product of the reflectance and the reproduction power is substantially the same among the information layers. Thus, the information reproduction can be conducted at high quality.

Abstract: The present invention provides a novel physical structure for a multilayer optical information recording medium including a plurality of information recording layers, and a recording method and a recording/reproduction apparatus for such a recording medium using the same. The multilayer optical information recording medium according to the present invention includes a test recording area for performing test recording for data recording and/or reproduction conditions in at least one of an inner zone and an outer zone. The test recording area is categorized as one of at least two categories of test recording areas (OPC-A area and OPC-B area). In the OPC-B area, an upper limit value is set on a recording power for the test recording.

Abstract: An optical disk includes a land and a groove. The optical disk has a data efficiency of 80% or more. Data is recorded on both the land and the groove. A distance between the center of the land and the center of the groove adjacent to the land is 0.28 ?m or more. Thus, an optical disk having a storage capacity of 25 GB or more can be provided.

Abstract: An optical disc medium 10 having a wobbled track groove 12 includes three wobble patterns including a flat wobble pattern, a positive pulse wobble pattern, and a negative pulse wobble pattern. In the flat wobble pattern, the amplitude of the wobble from the lengthwise direction of the track groove is zero such that the track groove is flat. In the positive pulse wobble pattern, the amplitude of the wobble from the lengthwise direction of the track groove is positive such that the track groove is wobbled in a first direction perpendicular to the lengthwise direction. Further, in the negative pulse wobble pattern, the amplitude of the wobble from the lengthwise direction of the track groove is negative such that the track groove is wobbled in a second direction opposite to the first direction. Then, three data values can be recorded using three distinctive wobble patterns.