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: A servowriting method for a patterned-media magnetic recording disk uses a special position error signal (PES) alignment pattern located in each servo sector. A gross feedforward correction signal to compensate for gross eccentricity of the disk relative to the center of rotation of the servowriter spindle is applied to the actuator. With the gross feedforward correction applied to the actuator the read head generally follows a data track centerline and will detect signals from PES alignment fields as each servo sector passes the read head. This results in a readback signal at each servo sector that represents the fractional track-width radial offset of the read head in that servo sector from a data track centerline. The set of radial offsets for all of the servo sectors is used to modify or fine tune the gross feedforward correction signal that is applied during the servowrite process.

Abstract: An information storage medium has user data areas and additional data areas, and sync patterns to distinguish the additional data areas from the user data areas. The information storage medium includes a user data area in which user data is recorded and an additional data area located in at least one of areas before and after the user data area. Second sync patterns used in the additional data area are different from first sync patterns used in the user data area.

Abstract: An information storage medium is provided with a plurality of information storage layers, each of which includes an optimal power control (OPC) area for obtaining an optimal recording condition. Optimal power control areas in odd-numbered and even-numbered information storage layers viewed from a direction in which light is incident upon the information storage medium are disposed one on another to not directly face each other. An actually usable area of an optimal power control area in each of the information storage layers varies depending on use circumstances of each of the information storage layers. Therefore, when an OPC area of one information storage layer performs OPC, this OPC does not affect another information storage layer. Also, an area of each of the information storage layers can be efficiently used.

Abstract: A substrate in which a minute ruggedness structure including columnar projections is formed in a track shape is prepared. The pitch of the columnar projections of the ruggedness structure is set such that a plurality of the columnar projections is within a beam spot. A flat portion is disposed between adjacent tracks. A reflecting layer is formed on the substrate. The flat portion becomes a mirror surface because of the formation of the reflecting layer. The reflectance of the ruggedness structure becomes significantly lower than the reflectance of the flat portion. When the ruggedness structure is irradiated with high-power laser light, a portion of the ruggedness structure is raised to a reflecting layer side and flattened. At this time, reflectance of the raised portion becomes higher than reflectance of a non-raised portion. When a track including the ruggedness structure is irradiated with high-power pulse laser light, signal recording based on a change in reflectance is possible.

Abstract: A method and device for recording multiple information volumes on a record carrier, usually called multi-session recording, has a mapping unit (31) for opening a session by recording intro data including a first buffer zone at the beginning of the start zone of the volume, and a session control block (SDCB) in a remaining blank area of the start zone after the buffer zone. The session control block includes volume data indicative of the status and the contents of the session. The session is closed by recording session control data indicating that the information volume is closed in the remaining blank area, and closure data after the last user information recorded in the data zone for constituting the end zone of the volume. Further, the device has a detecting unit (32) for retrieving the session control block from said start zone.

Abstract: A write-once disc, an apparatus for recording information thereon, and a method of reducing access time thereto the write-once disc including at least one record layer. The write-once disc also includes at least one update area in which updated predetermined information is recorded; and an access information area in which location information regarding the updated predetermined information, is recorded for a predetermined period. Accordingly, it is possible to reduce an access time for reading information updated in the write-once disc on which predetermined information is updated and recorded on a new position.

Abstract: On an optical disk medium, a spare area is allocated separately from a recording area. If the recording area includes a defective sector, alternate recording for the defective sector is performed in the spare area. An optical disk drive comprises: a medium information acquisition part which acquires, from the optical disk medium, medium information specific to the medium; and an area size determination part which determines the spare-area size suitable for the medium on the basis of the acquired medium information. The medium information is information about, for example, a media manufacturer, and a media type number. Further, there is provided a table which stores the relationship between the medium information and the optimum size of the spare area.

Abstract: Various embodiments of the present invention provide systems and methods for sector address mark detection. As an example, data detection systems are disclosed that include a sector address mark detection circuit and a sector address mark quality detection circuit. The sector address mark detection circuit receives a data stream and identifies a sector address mark in the data stream. The sector address mark quality detection circuit receives a first sample and a second sample from the data stream corresponding to the sector address mark, and determines a quality of the sector address mark based at least in part on the first sample and the second sample. In various cases, one or more of the samples of the sector address mark up to all of the samples of the sector address mark may be used.

Abstract: A multi-layered information recording medium including a plurality of recording layers, the multi-layered information recording medium comprising: a user data area for recording user data; and a plurality of spare areas including at least one replacement region, wherein when the user data area includes at least one defect region, the at least one replacement region may be used in place of the at least one defect region, wherein a first spare area of the plurality of spare areas is positioned so as to be contiguous to a first user data area of a first recording layer, a second spare area of the plurality of spare areas is positioned so as to be contiguous to a second user data area of a second recording layer, and the first spare area and the second spare area are positioned approximately at the same radial position on the multi-layered information recording medium.

Abstract: A method and system for authenticating a digital optical medium, such as a CD-ROM, determine whether the medium is an unauthorized copy, or the original. The original media is created, or altered, so as to contain anomalous locations from which the transfer of data is accomplished at different rates than a standard digital copy would exhibit. One implementation of the process involves timing analysis of the differences in data transfer rates. Another implementation involves the determination of digital signatures during multiple read operations performed on a data segment. The process can be employed in systems that control access to unauthorized copies, or may be used for other informative purposes.

Abstract: According to one embodiment, an optical recording medium is provided in which interlayer crosstalk is low and in which stable and high-quality recording characteristics can be obtained. To this end, an optical recording medium comprises a first recording part which includes a first recording layer and a first light reflecting layer and which is disposed on a side closer to a light receiving surface, and a second recording part which includes a second recording layer and a second light reflecting layer and which is disposed on a side farther from the light receiving surface, the first recording part and the second recording part being stacked, wherein the thickness of the second light reflecting layer is larger than the thickness of the first light reflecting layer.

Abstract: OPC areas are used for adjusting recording parameters (power and strategy). In an optical disc including two recording layers, the recording power for one recording layer is likely to be influenced by a transmittance variance or the like provided by the recording state of the other recording layer (either already recorded or unrecorded). In addition, recording is performed while changing the power. For these reasons, the OPC areas are located so as not to be at the same radial positions among the recording layers. However, as the number of recording layers is increased, the area size for securing the OPC areas is increased, which may undesirably lead to an increase of the lead-in zone or the lead-out zone (decrease of the user data zone) and a decrease of the OPC area size in each recording layer (decrease of the number of times of usage by the user).

Abstract: A disc-shaped information recording medium includes a laminate of recording layers on and from which an information signal can be optically recorded and reproduced from one side of the medium. Data areas are provided in the recording layers, respectively. The information signal can be recorded on and reproduced from the data areas while a laser beam emitted from an optical pickup is applied to the data areas. Optical recording test areas are provided in the recording layers, respectively. A test signal can be recorded on and reproduced from the optical recording test areas to decide optimum power values of the laser beam for signal recording. The test areas are out of overlap as viewed in a direction of propagation of the laser beam.

Abstract: An optical disc (102) and method for forming the same. The optical disc preferably includes a first substrate (150) comprising a pre-recorded, first data storage layer (152) and a second substrate (156) comprising a recordable, second data storage layer (158). The second substrate is affixed to the first substrate such that a data transducing beam (161) passes through a common exterior boundary surface (162) of the disc to access the respective first and second layers. Preferably, the pre-recorded layer comprises a sequence of pits and lands (218). Addresses of blocks in the respective layers preferably successively increment (220) so that a readback system (100) interprets the respective layers as a common recording layer within the disc. One of the layers can store disc authentication data zone, a patch which updates a version of user data stored in the remaining layer, etc. A content supplier can supply specially configured substrates with pre-recorded control data to control disc manufacture.

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 information recording medium comprising: a first recording layer in which a first recording track path to record therein record information is formed; and a second recording layer which is laminated on said first recording layer and in which a second recording tack path to record therein the record information is formed in a direction opposite to the first recording track path, in one recording layer of said first and second recording layers, a predetermined area in which focus leading of laser light is performed reflecting the laser light, in the other recording layer of said first and second recording layers, a facing area which faces the predetermined area not reflecting the laser light.

Abstract: An optical-disk recording method, recording apparatus and reproducing apparatus are provided which are capable of continuously recording/reproducing a hologram with ultra-high density. In the case of recording a hologram to a holographic recording area, a holographic recording spot HSP on one track of the holographic recording area and a holographic recording spot HSP on a track adjacent thereto are recorded in circumferentially different positions. At least one holographic recording spot HSP is formed on each track, making the process continuous. Recording is made such that, provided that the holographic recording spot HSP has a diameter D and a multiplex number of holographic recording spots HSP is m, a pitch P between adjacent holographic recording spots HSP is P=D/m. Consequently, it is possible to efficiently record a hologram with density to a holographic recording area of an optical disk recording medium, and to achieve the density increase of holographic recording capacity.

Abstract: An information recording apparatus (300) is for recording record information onto an information recording medium (100) comprising a first recording layer (L0 layer) and a second recording layer (L1 layer) to record therein the record information by irradiating laser light. The information recording apparatus is provided with: a recording device (352) for recording the record information into at least one of the first recording layer and the second recording layer by irradiating the laser light; and a controlling device (354) for controlling the recording device to record the record information into a target area (115a), which is a recording area of the second recording layer corresponding to a recording area (105a) of the first recording layer in which the record information is recorded, if the record information is recorded into the second recording layer.

Abstract: 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.

Abstract: An optical disc apparatus for recording information on a rewritable optical disc having a power calibration area (PCA) moves an optical pickup for optimum recording power calibration (OPC) from an innermost end to outward of the PCA, and stores an address where RF signal is first detected. If the stored address coincides with an address at the innermost end of the PCA, or if a usable area between the two addresses is smaller than to enable one-time OPC, the apparatus obtains an optimum recording power by overwriting on a used area at or near the innermost end of the PCA, and performs DC erase using the obtained optimum recording power. This enables DC erase and restoration of the PCA back to a usable area even if the PCA has no usable area at its innermost end, and even if it is difficult to detect a usable area in the PCA.

Abstract: An information recording medium (100) is provided with: a first recording layer (L0 layer) and a second recording layer (L1 layer) in each of which record information can be recorded, the information recording medium includes a plurality of block areas, each of which is a unit of recording the record information and each of which includes a partial recording area of the first recording layer (105a) and a partial recording area of the second recording layer (115a) located in a position facing the partial recording area of the first recording layer.

Abstract: An information storage medium has user data areas and additional data areas, and sync patterns to distinguish the additional data areas from the user data areas. The information storage medium includes a user data area in which user data is recorded and an additional data area located in at least one of areas before and after the user data area. Second sync patterns used in the additional data area are different from first sync patterns used in the user data area.

Abstract: The data structure includes a navigation area of a computer readable medium storing navigation data associated with a data stream representing a portion of at least one reproduction path. The navigation data includes indication information, and the indication information indicates whether the data stream represents multiple reproduction paths or the data stream represents a single reproduction path. If the indication information indicates the data stream represents multiple reproduction paths, the navigation data includes path number information and an indicator associated with each reproduction path. The path number information identifies a number of the multiple reproduction paths, and each indicator indicates a file associated with the associated one of the multiple reproduction paths.

Abstract: An inspection apparatus for inspecting a phase modulated wobble track of an optical disk is provided. A radial push-pull signal (a wobble signal) of an optical disk is supplied to a low pass filter where a phase boundary portion of the wobble signal is smoothed, and then binarized by a binarizer and supplied to a time interval analyzer. The time interval analyzer analyzes a period of the binary wobble signal to extract two peak values T1 and T2 thereof. An operation device computes a difference value of the two periods T1 and T2 and a standard deviation of each peak, and compares each computed value to a threshold value for simultaneously evaluating CNR and a phase shift. The low pass filter and the binarizer may be incorporated into an optical disk apparatus for smoothing the phase boundary portion of the reproduced wobble signal.

Abstract: A recording/playback device includes an information conversion unit converting video or audio information, received from an external source, to video or audio data for recording on a rewritable optical disk, a recording unit recording the video or audio data on said optical disk, and a playback unit playing back the video or audio data recorded on said optical disk, in which the optical disk has at least two recording layers and, when the video or audio data is recorded in two or more layers of the optical disk and then a part of the video data or audio data recorded in each layer is erased, a part of the video or audio data left unerased is moved so that a number of layers, in which the video or audio data left unerased is recorded, is reduced.

Abstract: A high-density optical disc such as BD-RE (Blu-ray Disc Rewritable) or BD-ROM, and a recording/reproducing method thereof are disclosed. Diverse additional information such as disc reflectivity information, disc layer information or disc type information is efficiently recorded in a particular information field included in a data unit recorded on the burst cutting area of a high-density optical disc or a particular 1-byte address field included in an address unit recorded on the high-density optical disc so that it can be read when the high-density optical disc is loaded in an optical disc apparatus or when a data recording or reproducing operation for the high-density optical disc is carried out. Accordingly, it is possible to achieve optimal optical power control and automatic gain control or identification of a current position, while enabling a normal data recording or reproducing operation corresponding to the type of the optical disc.

Abstract: The same contents having different recording rates are recorded on a multi-layer disk. A plurality of contents or the same contents having different recording rates are independently recorded respectively in different layers of an optical disk having a plurality of recording layers. In order to record a plurality of contents or the same contents having different recording rates in parallel at that time, recording on the multi-layer optical disk is conducted by repeating an operation of dividing each content into recording units, recording a recording unit of one kind of information in a recording layer, and recording a recording unit of the other kind of information in a different recording layer.

Abstract: 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.

Abstract: A multi-layer record carrier is for recording information by writing marks in a track. The record carrier has a first recording layer (40) and a second recording layer (41), and each recording layer has a pregroove (14) indicating the position of the track according to an opposite track path. The pregroove exhibits a modulated wobble for representing control information. A lead-in part of the pregroove has first control information for the first recording layer, and the lead-out part on the second recording layer has second control information including recording parameters for the second recording layer. The device the device has a head (22) for providing the beam and wobble detection means (32) for retrieving control information from each layer.

Abstract: An information recording medium is provided, which comprises a plurality of recording layers and a first disc information area for storing parameters relating to access to the plurality of recording layers and formats relating to the plurality of recording layers. The first disc information area is provided in a first recording layer which is one of the plurality of recording layers.

Abstract: A method for recording a unique ID to a read-only optical disk adopts the 1-7 PP modulation technique and provides in a plurality of predetermined positions postscript areas each having a predetermined postscript pattern. The postscript pattern takes a form of 3T (pit)-2T (land)-3T (pit) and has a length of 8T (largest code length of a modulated bit string). Modulated bit strings before and after the 3T-2T-3T postscript pattern are formed so that the pit-land-pit postscript pattern complies with the rule of the variable-length modulation even when it is replaced as a whole with a pit-only pattern. Further, the land in the middle will not physically change when irradiated with laser light having a reading-level power, but will be melted with a power higher than the reading-level one.

Abstract: Recordable DVD+R and DVD+R/W optical discs with two (or more) information layers are developed to double the data storage capacity and video recording time. A method and device are proposed to make dual layer DVD disc recordings compliant with the dual layer DVD-ROM standard Recording the data in a DVD-ROM compliant way on the dual layer DVD+R or DVD+R/W disc is obtained by shifting the middle zone area towards the inner radius of a disc in such a way that the data zones of both layers are filled up with data.

Abstract: Disclosed herein are a high-density recording medium and a method and apparatus for controlling data playback thereof. Playback control information, such as channel bit length information, is recorded in a burst cutting area (BCA) of a high-density optical disc in a wobble type. When the high-density optical disc is reproduced, the playback control information is detected in a push-pull signal detection mode and the optimum data playback operation corresponding to the recording capacity of the optical disc is performed on the basis of the detected playback control information. Alternatively, bit error rates (BERs) are calculated while a plurality of predetermined bit detection modes are sequentially performed, one of the bit detection modes corresponding to the smallest one of the calculated BERs is selected and the data playback operation is performed in the selected bit detection mode.

Abstract: A record carrier is described comprising a zone with a visually detectable pattern composed of pattern elements arranged along at least one track. The pattern elements comprise a marked zone having an optical property deviating from a background, the marked zones having a width Wm transverse to the track direction and a length Lm along the track direction, wherein at least two or more pattern elements have a marked zone with a mutually different width Wm. In this way, an increased visibility of the visual pattern is achieved. Likewise a method and an apparatus for recording an optical record carrier is included.

Abstract: A disc-shaped information recording medium includes a laminate of recording layers on and from which an information signal can be optically recorded and reproduced from one side of the medium. Data areas are provided in the recording layers, respectively. The information signal can be recorded on and reproduced from the data areas while a laser beam emitted from an optical pickup is applied to the data areas. Optical recording test areas are provided in the recording layers, respectively. A test signal can be recorded on and reproduced from the optical recording test areas to decide optimum power values of the laser beam for signal recording. The test areas are out of overlap as viewed in a direction of propagation of the laser beam.

Abstract: A method of recording control information in a recording medium, such as an optical disc, including at least one recording layer is provided Velocity information and per recording velocity write strategy (write strategy parameters) is included in control information, such that standardized control information can be uniformly applied to cope with the playback of a recorded optical disc. The method includes steps of recording, per applicable recording velocity, the control information within a management area of the at least one recording layer of the optical disc; and recording at least one write strategy information per the applicable recording velocity within the control information.

Abstract: A recording medium having at least one control data area storing control data in a recording unit. The control data may be used for managing an access to the recording medium. The medium having at least one management area storing status information for the control data area, wherein an invalid recording unit in the control data area is skipped and next available recording unit is used.

Abstract: In an optical disk including at least a rewritable phase change material and comprising a recording layer having a reflectivity of more than 15%, an address output value as an address pit signal component occupying in a reproduced signal in a non recording state is prescribed to be 0.18 though 0.27 or a numerical aperture of an address pit signal occupying in a reproduced signal in a non recording state is prescribed to be more than 0.3.

Abstract: An optical information recording medium includes a recording layer in which a track is formed, the track having recording marks linearly arranged thereon. Each recording mark has a dimension corresponding to a reference mark length, which serves as a reference, in a track direction along which the track extends, the dimension being smaller than dimensions of the recording mark in two directions perpendicular to the track direction.

Abstract: An information storage medium according to the present invention has n information storage layers (where n is an integer and n?3), on which data can be written with a laser beam and which are stacked one upon the other. Each of the n storage layers has a test write zone for determining the recording power of the laser beam. When those n layers are counted from the one that is located most distant from the surface of the medium on which the laser beam is incident, there is a bigger radial location difference between the outer peripheral end of the inner one of the test write zones of ith and (i+1)th information storage layers (where i is an integer that satisfies 2?i?n?1) and the inner peripheral end of the other outer test write zone than between the outer peripheral end of the inner one of the test write zones of jth and (j+1)th information storage layers (where j is an integer that satisfies 1?j?i?1) and the inner peripheral end of the other outer test write zone.

Abstract: A multi-layered information recording medium including a plurality of recording layers, the multi-layered information recording medium comprising: a user data area for recording user data; and a plurality of spare areas including at least one replacement region, wherein when the user data area includes at least one defect region, the at least one replacement region may be used in place of the at least one defect region, wherein a first spare area of the plurality of spare areas is positioned so as to be contiguous to a first user data area of a first recording layer, a second spare area of the plurality of spare areas is positioned so as to be contiguous to a second user data area of a second recording layer, and the first spare area and the second spare area are positioned approximately at the same radial position on the multi-layered information recording medium.

Abstract: In an optical disk including at least a rewritable phase change material and comprising a recording layer having a reflectivity of more than 15%, an address output value as an address pit signal component occupying in a reproduced signal in a non recording state is prescribed to be 0.18 though 0.27 or a numerical aperture of an address pit signal occupying in a reproduced signal in a non recording state is prescribed to be more than 0.3.

Abstract: A visible pattern is obtained by modulating the digital sum value. Because the digital sum value modulation allows the choice of several different channel bits groups between DC control points, the selection of a group of channel bits resulting in a change of reflection. This creation of a visible pattern is highly suitable for Blueray as the parity preserving property of the channel code guarantees disparity inversion by the DC-control bit, which keeps the DSV excursions between hard limits. As a result only small DSV deliberate variations are required to produce a visual watermark, which will not deteriorate the bit-detection margin of the optical disc.

Abstract: Stable focus servo and tracking servo are realized in an information recording medium having a plurality of recording regions having different track pitches and groove shapes.

Abstract: A read-only recording medium and a reproducing method thereof ensures reproduction compatibility with a rewritable recording medium in which real data is recorded with substantial discontinuity. The read-only recording medium comprises a data recording area in which real data is stored; and a plurality of waste areas allocated at intervals in the data recording area. The method of reproducing data stored in a read-only recording medium reproduces data from the read-only recording medium, skips if a waste area is encountered or removes invalid data reproduced from the waste area wherein each waste area has been inserted periodically in the read-only recording medium, and outputs the data reproduced before and behind each waste area in succession. As a result, the playability is improved in a disk device capable of reproducing both a read-only and a rewritable recording medium.

Abstract: A write-once-type recording medium (100) on which record data can be recorded only once, provided with: a data area (108) to record therein the record data; and a shared area (104, 105) to temporarily record therein evacuation data which is record data to be recorded or already recorded at a position of a defect in the data area and defect management information (120) including an evacuation source address of the evacuation data, the evacuation data being recorded with one predetermined point which exists in the shared area as a start point, the defect management information being recorded with another predetermined point which exists at a different point from the one point as a start point, in the shared area.

Abstract: In an optical disk including at least a rewritable phase change material and comprising a recording layer having a reflectivity of more than 15%, an address output value as an address pit signal component occupying in a reproduced signal in a non recording state is prescribed to be 0.18 though 0.27 or a numerical aperture of an address pit signal occupying in a reproduced signal in a non recording state is prescribed to be more than 0.3.

Abstract: An information storage medium has user data areas and additional data areas, and sync patterns to distinguish the additional data areas from the user data areas. The information storage medium includes a user data area in which user data is recorded and an additional data area located in at least one of areas before and after the user data area. Second sync patterns used in the additional data area are different from first sync patterns used in the user data area.

Abstract: An information recording medium is provided, which comprises a plurality of recording layers and a first disc information area for storing parameters relating to access to the plurality of recording layers and formats relating to the plurality of recording layer. The first disc information area is provided in a first recording layer which is one of the plurality of recording layers.