Abstract: In a write-once media, by using a selected area such as an area starting from a postscript-recording point in the main data area as an alternate area, by determining whether or not an address specified in a request such as a write request is an address at which data has been recorded on the basis of information on a sequential recording range and by recording pieces of alternate-address management information for replacing defective locations on the media and for renewing data recorded on the media in a table by letting the pieces of information coexist in the table, defective locations on the media can be replaced with other locations and data already recorded on the media can thus be renewed even without providing pre-allocated alternate area on the media. In addition, if the media is provided with an alternate area and the alternate area becomes insufficient for alternate-address processing, a selected region in the main data area can be used as a region supplementary to the insufficient alternate area.

Abstract: A recording medium, and a method and apparatus for recording and/or reproducing management information on/from the recording medium are discussed. According to an embodiment, the invention provides an apparatus includes components so that the apparatus finalizes the recording medium when receiving request of an external host or when a temporary defect management area located in at least one of a non-data area and a non-user data area becomes full, where a controller is configured to control the components so that the apparatus records the latest defect list information written in the temporary defect management area onto a final defect management area when finalizing the recording medium.

Abstract: A write once disc, a disc drive therefor, and a method of managing disc defects on the write once disc using the disc drive in consideration of the compatibility of the write once disc with a rewritable disc drive, the write once disc includes a single record layer disc in which a lead-in area, a data area, and a lead-out area are sequentially formed and a first spare area and a second spare area are sequentially formed in the data area. The write once disc includes a defect management area (DMA) formed in at least one of the lead-in area and the lead-out area; a first temporary defect management area (TDMA) formed in at least one of the lead-in area and the lead-out area; and a second TDMA formed between the first spare area and a user data area or between the user data area and the second spare area.

Abstract: A drive apparatus of the present invention includes a recording/reproduction section and a drive control section. The drive control section performs a process including: determining whether or not replacement management information including a replacement physical address is found in the replacement management information list, the replacement physical address matching the physical address corresponding to the logical address included in the recording instruction, when the replacement management information is not found, as a first time pseudo-overwrite recording for a location indicated by the physical address corresponding to the logical address included in the recording instruction, performing a process; and when the replacement management information is found, as a second time or more pseudo-overwrite recording for a location indicated by the physical address corresponding to the logical address included in the recording instruction, performing a process.

Abstract: An information recording medium, a method of recording and/or reproducing data to/from the medium, and a recording/reproducing apparatus using the medium, the medium having a data area including a user data area to record user data, and a spare area to record replacement blocks that replace defect blocks occurring in the user data area, wherein defect list entries include status information of the defect blocks and the replacement blocks, and the status information of the defect blocks in the user data area is changed, and the status information of the replacement blocks in the spare area is changed, in response to the spare area being newly allocated to re-initialize the medium.

Abstract: A system controlling recording on an optical disc is provided. A first counter performs a bit count according to provided channel bit clock signals. A second counter performs a sector count responsive to the bit count obtained by the first counter. The Land/Groove switch predicts machine uses the result of bit count and sector count to predict the land/groove switch point. The processor uses the physical ID (PID) to determine the track type of a sector at which a recording operation initiates. The power controller determines a recording power for the recording operation according to the Land/Groove switch predict machine.

Abstract: A method, apparatus and computer readable medium for managing recording medium defects and a defect managed recording medium. The recording medium includes a spare area in which a replacement area, which is a substitute for a defective area of the recording medium, is formed, and a temporary defect management area in which temporary management information that specifies the defective area and the corresponding replacement area is recorded, wherein position information and state information regarding the defective area are recorded in the replacement area. Accordingly, it is possible to restore defect information even if recording medium defect management on the recording medium ended abnormally.

Abstract: An information recording apparatus, an information recording system, a program, and a recording medium are disclosed, by which contents are legally recorded to another information recording medium. Copy-once contents stored in a first optical disk are written to the second optical disk. After this writing is completed, a laser light having power equal to recording power is irradiated to the first optical disk so that reproduction of the copy-once contents in the first optical disk is made impossible. In this way, the copy-once contents stored in the first optical disk are erased, and the contents are moved to the second optical disk without jeopardizing the “copy-once” attribute of the contents. That is, the contents can be legally moved to another information recording medium.

Abstract: An optical recording medium including a user data area and an SA/DL area in which a replacement block to replace a defective block in the user data area, and information regarding a defect corresponding to the defective block, is recorded, wherein the information regarding the defect includes a consecutive defect list entry including information regarding defects located in consecutive locations of the user data area; an apparatus using the optical recording medium; and a method of using the optical recording medium.

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: An information recording medium, a method of recording and/or reproducing data to/from the medium, and a recording/reproducing apparatus using the medium, the medium having a data area including a user data area to record user data, and a spare area to record replacement blocks that replace defect blocks occurring in the user data area, wherein defect list entries include status information of the defect blocks and the replacement blocks, and the status information of the defect blocks in the user data area is changed, and the status information of the replacement blocks in the spare area is changed, in response to the spare area being newly allocated to re-initialize the medium.

Abstract: A drive apparatus of the present invention includes a recording/reproduction section and a drive control section. The drive control section performs a process including: determining whether or not replacement management information including a replacement physical address is found in the replacement management information list, the replacement physical address matching the physical address corresponding to the logical address included in the recording instruction, when the replacement management information is not found, as a first time pseudo-overwrite recording for a location indicated by the physical address corresponding to the logical address included in the recording instruction, performing a process; and when the replacement management information is found, as a second time or more pseudo-overwrite recording for a location indicated by the physical address corresponding to the logical address included in the recording instruction, performing a process.

Abstract: An optical disk as disclosed herein includes, among other things, a summing module that sums a compensation signal to a predetermined signal in a servo loop. The compensation signal compensates for a periodical disturbance input into a servo system of the optical disk device in units of a rotation angle of the disk rotating module. A phase lead imparting module imparts a predetermined amount of phase lead to an output signal from an optical detector module and outputs the predetermined amount of phase lead as the compensation signal. The predetermined amount of phase lead is determined in accordance with the rotation period information. The optical disk device performs an accurate iterative learning control to provide stable servo performance. The iterative learning control is performed such that the signal having imparted an optimal amount of phase lead in accordance with the rotation period information is added to the servo loop.

Abstract: A write once disc allowing management of a data area, a method of managing the data area of the write once disc, an apparatus recording data on the write once disc, an apparatus and method of reproducing data from a write once disc. The write once disc, includes a lead-in zone, a data area, and a lead-out zone. The write once disc includes a predetermined area storing area allocation information which indicates whether at least one section of the data area is allocated for disc defect management. In the disc and method, area allocation information specifying a structure of the data area is recorded on the disc, thus allowing a recording/reproducing apparatus to recognize the data area structure. Therefore, allocating areas, such as a spare area, for disc defect management other than an area for storing user data, to the data area is possible. The allocation of the areas for disc defect management to the data area enables effective use of the write once disc.

Abstract: To provide a recording method of a multilayered optical disk having three or more recording layers, for performing recording while securing sufficient test areas without reducing user data areas, and while suitably controlling the power of laser beam irradiated onto each of the layers. The method uses an optical disk which has at least a first recording layer and a second recording layer located on the side nearer to the light incident surface than the first recording layer, and which respectively has a first test area configured by a plurality of segments in the first recording layer and a second test area configured by a plurality of segments in the second recording layer.

Abstract: An optical information storage medium includes a lead-in area, a user data zone in which user data is recorded, and a lead-out area. Write protection information is recorded in at least one of the lead-in area and the lead-out area, together with defect management information. Information is recorded and/or reproduced according to the defect management information and the write protection information. The write protection information indicates a size of a write protected area differentiated from a plurality of sizes of write protected areas of the optical information storage medium.

Abstract: It has been discovered that damage to an optical disc can be used as a damage signature for that optical disc. The damage signature can be digitally represented to uniquely identify the optical disc in combination with other identifying information that identifies the optical disc. Services, such as a restore service, can be provided to a user after validation of a digital damage signature of an optical disc.

Abstract: A write-once read-many information recording medium is provided, which is capable of easily searching for a latest DDS and a latest defect list. At least one disc management working area is sequentially allocated in a predetermined direction on the write-once read-many information recording medium of the present invention. The latest defect list and the latest DDS are provided in a recorded disc management working area neighboring a border between the recorded disc management working area and an unrecorded disc management working area, where the latest defect list precedes the latest DDS in the predetermined direction.

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: An information recording medium, and a recording/reproducing apparatus and a recording/reproducing method for the recording medium. Original data is sequentially updated by replacing an original recording block with one or more replacement recording blocks. A replacement recording block includes at least one of an original address field indicating a location of the original recording block or a previous address field indicating a location of an immediately previous recording block. Replacement information is effectively recovered in a system where a replacement for logical overwriting (LOW) occurs in either a spare area and a user data area by reference to the address fields in each replacement recording block.

Abstract: An optical disk apparatus according to the present invention includes: a rotation driving section on which an optical disk is to be mounted and which drives the optical disk so as to be rotated; a light source; an objective lens for converging light from the light source onto an optical disk mounted on the rotation driving section; a photodetector having at least two detection sections for detecting reflected light, from the optical disk, of the light; and an error signal generation section for deriving a difference signal and a sum signal of respective outputs from the two detection sections of the photodetector, adjusting an offset in at least the sum signal among the difference signal and the sum signal, and thereafter dividing the difference signal by the sum signal whose offset has been adjusted to generate a position error signal of the objective lens.

Abstract: A method and apparatus for recording or reproducing data are discussed. According to an embodiment, the invention is directed to a method for recording data onto a recording medium having a recording layer, the recording layer including an inner area, a data area and an outer area, the data area having a user data area and a spare area, the user data area consisting of a plurality of clusters, the method comprising steps of: (a) recording a first data block having a temporary defect list for managing a defective area of the data area onto a temporary defect management area allocated in the inner area or the spare area; and (b) recording a second data block having a space bitmap onto the temporary defect management area.

Abstract: A data managing method for an optical disc drive writing data into an optical disc having defects is provided. The optical disc has a user data area and a spare area. The optical disc drive includes a first buffering space and a second buffering space. The data managing method includes: when the first buffering space receives a data corresponding to a defect, not suspending the first buffering space from receiving the user data, and transferring the data, corresponding to the defect and in the first buffering space, to the second buffering space; and when data amount in the second buffering space reaches a predetermined value, suspending the optical disc drive from writing data in the first buffering space into the user data area, and driving the optical disc drive to write data in the second buffering space into the spare area.

Abstract: Within a disk recording/reproducing apparatus for improving a transfer rate when recording/reproducing, and an alternation process method for a disk for it, for recording or reproducing information onto/from an optical disk 100, while conducting a alternation on a defect block within a user data recording area into an alternation area, a controller 500 determines an alternation destination where data of an alternation origin are recorded therein, or a drive speed during the alternation process, upon basis of the position of the alternation origin on the optical disk, when conducting the alternation process.

Abstract: A write-once read-many information recording medium is provided, which is capable of easily searching for a latest DDS and a latest defect list. At least one disc management working area is sequentially allocated in a predetermined direction on the write-once read-many information recording medium of the present invention. The latest defect list and the latest DDS are provided in a recorded disc management working area neighboring a border between the recorded disc management working area and an unrecorded disc management working area, where the latest defect list precedes the latest DDS in the predetermined direction.

Abstract: A write-once read-many information recording medium is provided, which is capable of easily searching for a latest DDS and a latest defect list. At least one disc management working area is sequentially allocated in a predetermined direction on the write-once read-many information recording medium of the present invention. The latest defect list and the latest DDS are provided in a recorded disc management working area neighboring a border between the recorded disc management working area and an unrecorded disc management working area, where the latest defect list precedes the latest DDS in the predetermined direction.

Abstract: An optical disc of write once type, a method and an apparatus of managing defect information on the optical disc of write once type, e.g., a BD-WO, are provided with a temporary defect management area (TDMA). The method includes preparing the temporary defect management area (TDMA) in which a temporary defect list (TDFL) is recorded as defect management information for managing a defective area on the optical disc, recording the most recent temporary defect list cumulatively with the previous temporary defect list in the temporary defect management area, and recording position information for indicating a position of the most recent temporary defect list in the temporary defect management area along with the temporary defect list to more effectively manage the temporary defect list.

Abstract: A write-once recording medium recording/reproduction is carried out by performing a process including: determining whether or not replacement management information including a replacement physical address is found in the replacement management information list, the replacement physical address matching the physical address corresponding to the logical address included in the recording instruction, when the replacement management information is not found, as a first time pseudo-overwrite recording for a location indicated by the physical address corresponding to the logical address included in the recording instruction, performing a process; and when the replacement management information is found, as a second time or more pseudo-overwrite recording for a location indicated by the physical address corresponding to the logical address included in the recording instruction, performing a process.

Abstract: A write once disc allowing management of a data area, a method of managing the data area of the write once disc, an apparatus recording data on the write once disc, an apparatus and method of reproducing data from a write once disc. The write once disc, includes a lead-in zone, a data area, and a lead-out zone. The write once disc includes a predetermined area storing area allocation information which indicates whether at least one section of the data area is allocated for disc defect management. In the disc and method, area allocation information specifying a structure of the data area is recorded on the disc, thus allowing a recording/reproducing apparatus to recognize the data area structure. Therefore, allocating areas, such as a spare area, for disc defect management other than an area for storing user data, to the data area is possible. The allocation of the areas for disc defect management to the data area enables effective use of the write once disc.

Abstract: The present techniques provide methods and systems reading a data bit of interest on an optical data disc with a reduced error rate. The data bit estimation may be improved by reducing deterministic noise resulting from an optical reader system and/or the optical data disc. The reader may adjust the position of a detector to detect light scattered from the disc based on parameters of known noise sources. In one embodiment, the detector may be moved vertically in relation to the data bit of interest on the optical disc. In another embodiment, more than one detector may be used to detect light scattered from a data bit of interest. In embodiments, the positioning of the detector(s) may be based on system or disc parameters, and the detected scatterings may provide a data reading, improved for an optical return from a present micro-hologram.

Abstract: A recording method of an optical recording medium comprises irradiating the medium with a laser having m pulse sets each comprising a heating pulse and a cooling pulse, in which m is a natural number; and scanning the medium with the laser at a scanning speed v to record marks each of a length nT, in which n is a natural number of 3 or more and T is a clock cycle, wherein a length TCPn of a final cooling pulse is determined in accordance with the scanning speed v using the following functions, in v<v0, TCPn/T=f1,n(v) in v v0, TCPn/T=f2,n(v), where the f1,n(v) and f2,n(v) each represents a continuous function of the scanning speed v and satisfies the condition where an existence ratio of abnormal marks is 1.0×10?4 or less, and v0 is a selectable scanning speed.

Abstract: A method of overwriting data in a write-once information storage medium and a data recording and/or reproducing apparatus provided for overwriting data in such a write-once information storage medium. In the data overwriting method, a command to overwrite new data in a first area of the write-once information storage medium where data has already been recorded is issued. Then, the first area is considered as a defective area, and the new data is recorded in a second area. Thereafter, updated defect management information, including information about the locations of the first and second areas, is recorded in the write-once information storage medium. Accordingly, overwriting can be performed in write-once information storage media, which is incapable of physical overwriting, by using a logical overwriting technique. Thus, data recorded in the write-once information storage medium may be changed or updated.

Abstract: To enable sequential recording to be performed to alternate destinations and improve in access performance, by controlling to estimate sequential defective areas such as bubbles based on prescribed conditions, allocate blocks of a spare area (15) as alternate destinations of these areas, and perform alternate recording to the allocated alternate destinations, in response to a recording request to the sequential defective areas, because when defective areas such as bubbles on a disk (1) exist so as to extend in a wide range, alternate recording in a single block unit frequently occurs in recording to these areas, thereby possibly causing time-out to occur.

Abstract: The invention solves the problem that data cannot be recorded on a disc because the number of registered Defect Lists (DFLs) has reached a limit and the problem that the access performance is reduced at recording data reproduction time. A cluster, which is normally reproduced during verification processing and is preceded and followed by one or more defective blocks, is also treated as a defective block and, together with the preceding and following defective clusters, recorded in an spare area for extending the range in which clusters are registered as Contiguous Re-allocated Defect (CRD) entries. This reduces the number of DFLs to solve the problem that data cannot be recorded on the disc and, in addition, reduces the number of seek operations to prevent the access performance from being reduced at reproduction time.

Abstract: A write once disc allowing management of a data area, includes a lead-in zone, a data area, and a lead-out zone. The write once disc includes a predetermined area storing area allocation information which indicates whether at least one section of the data area is allocated for disc defect management. In the disc and method, area allocation information specifying a structure of the data area is recorded on the disc, thus allowing a recording/reproducing apparatus to recognize the data area structure. Therefore, allocating areas, such as a spare area, for disc defect management other than an area for storing user data, to the data area is possible. The allocation of the areas for disc defect management to the data area enables effective use of the write once disc.

Abstract: A data complementation method including a defective-data confirmation step of confirming if there is address information of defective data, a complementation-data confirmation step of confirming if complementation data is recorded, a complementation-data transmission request step of requesting a recovery server to transmit the complementation data, a complementation-data acquisition step of acquiring the complementation data through a communication network, and a complementation-data record step of recording the complementation data.

Abstract: A write once disc allowing management of a data area, includes a lead-in zone, a data area, and a lead-out zone. The write once disc includes a predetermined area storing area allocation information which indicates whether at least one section of the data area is allocated for disc defect management. In the disc and method, area allocation information specifying a structure of the data area is recorded on the disc, thus allowing a recording/reproducing apparatus to recognize the data area structure. Therefore, allocating areas, such as a spare area, for disc defect management other than an area for storing user data, to the data area is possible. The allocation of the areas for disc defect management to the data area enables effective use of the write once disc.

Abstract: A method for detecting a utilization status of an optical disc is disclosed. The method includes: accessing the optical disc to generate a radio frequency signal; generating an estimated blank signal according to the radio frequency signal; generating a first reference signal to indicate a DC level of the radio frequency signal according to the radio frequency signal; and detecting a true overwrite area of the optical disc according to said blank signal and the first reference signal.

Abstract: The present invention provides a data structure recorded in a recording medium, data recording method and data recording apparatus, in which data are recorded in a high-density recording medium such as a Blu-ray disc. In recording data per cluster within a recording medium, a data structure recorded in the recording system is characterized in that the data includes an address unit in which a plurality of per recording unit address fields included in a corresponding cluster and a control information field indicating per recording unit attribute are recorded and in that each information configuring the control information field is identified by byte unit.

Abstract: A recording method, a host apparatus, a recording and/or reproducing apparatus, an optical recording information storage medium, and a computer readable recording medium storing a program for performing the method of recording. The method of recording data on a disk includes: when new data is desired to be recorded on the disk, at an address at which data is already recorded, updating a defect list by writing in the defect list defect information of the address at which the data is already recorded; and transmitting to a recording and/or reproducing apparatus the updated defect list and a command to record the new data at the address at which the data is already recorded. According to the method, overwriting is implemented on a write-once medium and furthermore, when this overwrite is implemented, the load on the drive system is reduced.

Abstract: A write-once type optical disc and a method and apparatus for allocating a spare area on the write-once type optical disc are provided. The method includes allocating a data area on a recording medium of write-once type, and allocating a user data area and at least one spare area within the data area on the recording medium, the at least one spare area having a variable size, wherein a maximum recording capacity of the at least one spare area on the recording medium is less than a maximum recording capacity of at least one variable spare area on a rewritable type optical disc.

Abstract: An optical disk device for writing data into a disk including a plurality of recording layers, wherein the disk includes a recording layer in which a track for recording the data is formed in a clockwise spiral direction, and a recording layer in which a track for recording the data is formed in a counter-clockwise spiral direction, and the optical disk device records the data into a first recording layer, and selects a layer in which the data can be recorded and of which a spiral direction is opposite to the spiral direction of the first recording layer, as a recording layer for recording the data next to the first recording layer.

Abstract: An information recording medium, a recording and/or reproducing apparatus and a recording and/or reproducing method are provided. The recording apparatus includes: a write/read unit for recording data on an information storage medium in which a user data area for writing user data and a spare area for replacing a defect occurring in the user data area are disposed, and a replacement recording block to replace an original recording block recorded in the user data area is recorded in a non-recorded area of the spare area or the user data area; and a control unit for controlling the write/read unit so that a replacement entry indicating that part of the recording block is replaced is recorded on the storage medium. As a result, data reproduction time can be advantageously reduced so as to improve system performance, particularly, in a system where data replacement by logical overwrite (LOW) is implemented both in a user data area and a spare area, or in a system performing defect management.

Abstract: When a primary spare area is allocated for slipping replacement and linear replacement upon initialization, and a remaining portion of the primary spare area after slipping replacement and allocated for linear replacement after initialization are insufficient, a supplementary spare area is allocated. The sizes of the primary and supplementary spare areas are determined by the number of defects generated upon initialization. The information on the sizes of the spare areas, and the remainder state information representing the degree of use of the spare areas, are recorded, so that the spare areas can be efficiently managed. Also, in the defect management method, when an area that has already been linearly replaced is allocated as a supplementary spare area, defective blocks within the allocated supplementary spare area are not used for linear replacement, and the entries of a secondary defect list (SDL) with respect to the defective blocks are not changed.

Abstract: A disc with a temporary defect management information area and a defect management area includes a defect management area that is present in at least one of a lead-in area, a lead-out area, and an outer area, a temporary defect information area which is formed in the data area and in which temporary defect information is recorded, and a temporary defect management information area which is present in at least one of the lead-in area, and the lead-out area. Accordingly, it is possible to record user data in a recordable disc, especially, a write-once disc, while performing defect management thereon, thereby enabling efficient use of a defect management area having a limited recording capacity.

Abstract: A recordable optical disc includes a user area and a management information area. User data is recorded in a physical block used as a single unit, and the space bit map is recorded in the management information area. Integrity verification processing is performed for each of recording status information so as to verify the integrity of the recording status information indicating a recording status of the physical block and the recording status of the physical block on the recordable optical disc. The necessity of the integrity verification processing is determined by reading out the status information indicating the necessity of the integrity verification processing. When the integrity verification processing is determined to be necessary, the integrity verification processing is carried out for unverified recording status information of the recording status information of the space bit map.

Abstract: A recording medium, and a method and apparatus for recording defect management information on the recording medium are disclosed. The method for recording defect management information of a recording medium includes recording a defect entry on the recording medium, wherein the defect entry includes a first field that can identify a defect entry type, a second field recording position information of a defect area within a user data area, and a third field recording position information of a replacement area within a spare area, and recording position information corresponding to the second field and/or the third field in accordance with the defect entry type decided by the first field, wherein, in case of a defect entry type having no corresponding position information, the corresponding field is set to zero (0).

Abstract: In order to select the latest defect management information, the latest selection information first is selected by searching a plurality of selection information areas for a currently active selection information area in which the latest selection information is recorded and subsequently the latest defect management information is obtained by searching a plurality of defect management areas for a currently active defect management area in which the latest defect management information is recorded. If there is no unused defect management area in which defect management information can be alternatively recorded in lieu of the currently active defect management area, recording operation is limited.

Abstract: This document relates to a method capable of reducing transfer errors of a sled motor for moving an optical pickup to the outer circumference when labels are recorded on a disc. An optical disc recording method may comprise checking a step pattern having a small transfer error in the sled motor, and recording labels on a label plane of an optical disc while driving the sled motor based on the checked step pattern. Step patterns can be classified based on a structure of the sled motor or a unit for driving the sled motor. The step patterns having a small transfer error can be detected in a process of manufacturing an optical disc apparatus and stored in memory of the optical disc apparatus.

Abstract: Information recording media 101 and 102 usable for either a first recording density D1 or a second recording density D2 each include a user data area 106 in which user data is to be recorded, a first defect management information area 108 in which first defect management information for managing a defect area in the user data area is to be recorded, and a second defect management information area 109 in which second defect management information having an identical content to that of the first defect management information is to be recorded. The first and second defect management information areas 108 and 109 are located such that angles ?1 and ?2 made by start blocks thereof fulfill the relationships of 150°??1?210° and 150°??2?210° (?1: in the case of the first recording density, and ?2: in the case of the second recording density).