CA2482543A1

CA2482543A1 - Recording medium, method of configuring control information thereof, recording and/or reproducing method using the same, and apparatus thereof

Info

Publication number: CA2482543A1
Application number: CA002482543A
Authority: CA
Inventors: Jin Yong Kim; Sang Woon Suh
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2003-08-14
Filing date: 2004-06-25
Publication date: 2005-02-14
Anticipated expiration: 2024-06-25
Also published as: JP2007172835A; US7697384B2; ATE428173T1; CN101042886B; JP4778465B2; EP1884936A2; TWI346941B; CN1764963A; US7468936B2; US20070153652A1; US20050036414A1; AU2003303081A1; MXPA04007512A; TWI345776B; CN1764963B; CN101042887B; DK1676270T3; ES2325662T3; TW200506890A; DE602004020490D1

Abstract

A method of recording writing speed information and per writing speed write strategy information within disc control information is provided. The standardized disc control information can be uniformly applied to efficiently cope with the record/playback of the optical disc. In configuring disc control information within a management area of an optical disc including at least one recording layer, the method includes steps of providing the at least one disc control information within the management area, the disc control information provided per applicable writing speed to each of the at least one recording layer; and recording applicable recording speed information within the disc control information.

Description

Recording medium, Method of Configuring Control Information Thereof, Recording and/or Reproducing Method Using the Same, and Apparatus Thereof S
Technical Field Y
The present invention relates to a method of recording a control information on recording medium, such as a recordable optical disc having at least or_e recording layer, and more particularly, to a method in which writing speed information and write strategy parameters are included in the disc control information. Also, this invention relates to a method of recording or reproducing data on or from the recording medium using the writing speed information Background Art A high density optical recording medium, known as HD-DVD, is widely used to record and store high-definition video data , large amount program data, and nigh-quality audio data and so on. The Blu-ray disc represents next-generation HD-DVD
technology.
Technological specifications are now being established for the global standardization of the Blu-ray disc, including standards are for the write-once Blu-ray dlSC(BD-WO).
Meanwhile, a rewritable Blu-ray disc, known as the lx-speed BD-RE and now being discussed, should be compatible with BD-RE

discs expected to have higher writing speeds, i.e., the 2x-speed BD-RE and beyond. BD-w0 specifications for high writing speed are also in progress. Efficient solutions for coping with the high writing speed of a.high-density optical disc are urgently needed, and the specifications established should ensure mutual compatibility.
Disclosure of Invention Accordingly, the present invention is directed to an optical disc control information recording method that substantially obviates one or more problsms due to limitations and disadvantages of the related art.
An object of the present invention is to provide a method of recording disc control information as specified information corresponding to a plurality of writing speeds, by which writing speed information is included in the disc control information so that the recording and reproducing of an optical disc can be performed based ~on prerecorded disc information.
Another object of the present invention is to provide a data structure for configuring disc control information.
Another object of the present invention is to provide a method of recording, in a specific area of an optical disc, disc control information correspo-nding to a plurality of writing speeds, by which information for indicating applicability of a specific writing speed per recording .layer is recorded, to provide mutual compatibility between like-based discs [0143].
Another object of tie present invention is to provide a recording and reproducing method and apparatus thereof, by which user data can be recorded on and reproduced from an optical disc using prerecorded disc control information.
,_ Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these object s and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, in configuring disc control information within a management area ~of an optical disc including at least one or more recording layers, a method of recording the disc control information of the optical disc according to the present invention includes the steps of providing the at leas one disc control information within the management area, the disc control information provided per applicable writing speed to each of the at least one or more recording layers and recording applicable recording speed information within the disc control information.

In another aspec t of the present invention, a data structure for indicating recordable speed information is characterized in that the recordable speed information includes a respective recording speed flag to indicate whether a corresponding speed is applicable or not and ir~ that a first speed flag for a fist recording speed lower than a second recording speed is set to be dependent on a second speed flag for the second recording speed.
In another aspect of the present invention, a method of recording data on an optical recording medium includes the step of recording speed information on a specific area of the optical recording medium, wherein the speed information includes a respective recording speed flag to indicate whether a corresponding speed is applicable or not and wherein a first speed flag for a fist recording speed lower than a second recording speed is set to be dependent on a second speed flag for the second recording speed.
In another aspect of the present invention, a method of recording/reproducing data on/from an optical recording medium includes the steps of reading speed information from a specific area of the optical recording medium wherein the speed information includes a respective recording speed flag to indicate whether a corresponding speed is applicable or not and wherein a first speed flag for a fist recording speed lower than a second recording speed is set to be dependent on a second speed flag for the second recording speed and recording the data on a main data area of the optical recording medium based on the read speed information.
In another aspect of the present invention, a recording medium having speed information is characterized in that the speed 5 information includes a respective recording speed flag to indicate whether a corresponding speed is applicable or not and in that a first speed flag for a fist recording speed lower than a second recording speed is set to be dependent on a second speed flag for the secor_d recording speed.
In another aspect of the present invention, an optical disc includes at least ore recording layer provided with a recordable area and a recording-disabled or prerecorded area, .,;herein disc control information is separately recorded within the prerecorded area per the recording layer and wherein applicable recording speed information and v~rite strategy information according to a corresponding ~~~riting speed are recorded within the disc control information:
In another aspect of the present invention., an optical disc recording method includes the steps of if an optical disc having at least one recordirig layer is loaded, reading disc control information written within a management area of the optical disc per writing speed and reading to store applicable recording speed information recorded within the disc control information each and write strategy information fitting a corresponding writing speed, deciding the writing speed of the corresponding recording layer by referring to the stored speed information and write strategy information, and performing recording at the decided writing speed.
In another aspect of the present invention, an optical disc record playback apparatus includes a control unit delivering a recording command and a record playback unit receiving the recording command, the record playback. unit performing a recording in a manner of reading disc control information recorded within a management area of an optical disc per writing speed, reading to store applicable recording speed information recorded within the disc control information each and write strategy information recorded by interworking with a corresponding writing speed, deciding a recording speed of a corresponding recording layer by referring to the read information, and performing recording at the decided recording speed.
It is to be understood that both the foregoing general description and the follo~~~ing detailed description of the present invention are exemplary and ~explana ory and are intended to provide further explanation of the invention as claimed.
Brief Description of Drawings The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments) of the invention and together with the description serve to explain the principle of the invention.
In the drawings:
FIG. 1 is a diagram of a-single-layer disc applicable to the present invention;
FIG. 2 is a diagram of a dual-layer disc applicable to the present invention;
FIG. 3 is a diagram of a management area where disc control information of the present invention is recorded, in which a format of recording the disc information in a corresponding area is schematically shown;
FIGS. 4A to 4D are diagrams of disc information recorded according to a first embodiment of the present invention;
FIGS. 5A to 5B are diagrams of disc information recorded according to a second embodiment of the present invention;
FIGS. 6A to 6C are diagrams of disc information recorded according to a third embodiment of the present invention;
FIGS. 7A and 7B are diagrams of disc information recorded according to a fourth embodiment of the present invention; and FIG. 8 is a block diagram of an optical disc recording and reproducing apparatus using disc control information according to the present invention.
Best Mode for Carrying Out the Invention Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, s the same reference numbers will be used throughout the drawings to refer to the same or like parts.
A Blu-ray disc is taken as an example of an optical disc according to the present invention. Yet, the concept of the present invention, characterized in an optical disc having its disc control information recorded thereon, is applicable to ,_ DVD-RAM, DVD-R~A, DVD+RW, DVD-R, DVD+R, and similar such discs.
Although the terminology used herein is well known fox the most part, some terms have been chosen by the applicant, such that the present invention should be understood with the intended meanings of the terminology as used by the applicant.
For example, the "disc' control information" of a disc is recorded in a specified area; i.e., a recordable area of the disc or a prerecorded area (sometimes known as an embossed area, in which manufacturer data is recorded and where no further recording is possibl.e), and includes information necessary for the playback'of a recorded disc. Disc control information i s called "disc information" or "DI!' in relation to Blu-ray disc technology but is typically referred to as "physical format information" for DVD-RAM, DVD-RW, DVD+RW, DVD-R, and DVD+R discs. Hence, it should be apparent that the technical background of the present invention is equally applicable to physical format information.
Moreover, the disc information according to the present invention is recorded as an unspecified unit of information, which may be counted, for example, as a first or second information.
FIGS. 1 and 2 illustrate. the structure of optical discs according to the present invention, in which any. recordable optical disc may be applicable to the present invention. The recordable disc may be, for example, a rewritable optical disc or a write-once optical disc.
Referring to FIG. 1, illusCrating an optical disc having one recording layer, a lead-in area is provided as a management area on an inner circumference area of an optical disc, whereas a lead-out area is provided as a management area on an outer circumference area of the optical disc. In the inner circumference area, a pre-recorded area and a rewritable (or write-once) area are provided separately. In BD-RE and BD-WO
technology, the pre-recorded area is. called the PIC area, where permanent information and control data is recorded, and disc information is recorded in the PIC area. A data area is made up of a user data area where user- data is recorded and inner and outer spare area ISA and OSA, which are used in the replacement of the data of a defective area . In the case of a BD-Y~70 disc, a temporary defect management area (TDMA) is provided for recording information of a defect and for general management. The TDMA is unnecessary in the case of BD-RE discs, which have a corresponding area designa ed as reserved.
The present invention intmds to provide a method of recording disc information (DI) as disc control information required for recording and/or reproducing of a disc in a pre-recorded or recordable are. It is apparent that a recording method in the pre-record area is differently applied to each kind of disc.
Ln the case of BD-RE and BD-WO discs, the pre-recorded area is 5 the PIC area recorded using a bi-phased high-frequency modulated signal reproduced according to a specific playback method, to acquire the disc information.
FTG. 2 illustrate s an optical disc having dual recording layers, in which an inner circumference area of the disc has a 10 lead-in of a first recording layer (Layer 0) corresponding to a lead-out of a second recording layer (Layer 1). In this case, one PIC area is provided in each of the lead-in and lead-out areas, and the same disc information is recorded in each PIC
area.
FIG. 3 illustrates a PIC area formatted according to the present invention. In configuring the disc information of the PIC area of a BD-RE or BD-WO disc, the minimum recording unit is one cluster, 544 clusters constitute one fragment as one upper record unit, and five fragments make up the PIC area.
Disc information is recorded in a front head cluster of a first fragment IFO. The disc information is plurally recorded per recording layer and recording velocity permitted by the corresponding optical disc. One disc information includes 112 bytes, sometimes referred to as a Dl frame. To cope with a loss of disc information, the same contents of the disc information are repeatedly recorded in each front head cluster of the remainder of the fragments.
Information representing the corresponding recording layer, information representing recording velocity, and write .5 strategy inzormation corresponding to the recording velocity are included in each disc information. Such information is '-utilized in recording and reproducing the optical disc, to provide optimal recording power per recording layer and per recording velocity.
The disc information of the present invention is characterized in providing specific recording velocity informatior_ supported by the disc and associated write strategy information, and more specifically, in providing specific recording velocity supported for each recording layer and associated write strategy information via a specified method for discs having a plurality of recording layers The specific configuration of the disc information is for a Blu-ray disc, which may differ from the configuration of a DVD-based disc. Specifically, the recording DI volume for a B1u-ray disc is 112 bytes or equivalent. By configuring the disc information of the same recording layer as one information, i.e., ~r;ithout repeating any common information, the write strategy configuration may differ per recording velocity.
FIGS. 4A to 4D are diagrams of recording disc information according to a first of four embodiments of the present ' I2 invention, in which appli.~able writing speed information is recorded.
To acquire disc information associated with a specific writing speed of an intended specific recording layer from a plurality of existing disc information; all the disc information should be read, which is time consuming. For instance, if there are four recording layers and eight writing speeds applicable per recording layer, a total of 32 disc information are needed. A
recorder/reproducer (FIG. 8) should search all 32 disc information whenever a value of the disc information for the specific recording layer and writing speed is needed. Hence, the present invention is characterized in including disc-applicable writing speed information and a disc's recording layer information (number of layers) in the disc information, to enable a disc information search by a specified method using the recorded information. This information, which determines the sequence of a plurality of disc information, is commonly included (copied) in each dish information, thereby facilitating the access of the disc information for a specific recording layer and writing speed.
Moreover, one write strategy (WS) is recorded within each disc information and identification information for identifying a kind of the corresponding write strategy (WS) is separately recorded, whereby a record playback apparatus (FIG. 8) is facilitated to use the write strategy (WS). Moreover, by selecting to record one write strategy (WS) for a specific . 13 writing speed and a specific recording layer in disc information, a disc manufacturer can be provided with convenience.
Referring to FIG: 4A, illustrating a disc information structure, each disc information sequence is determined by a sequence number and is recorded using one byte. For instance, the information is recorded in a fifth byte (i.e., the "DI
frame sequence number in DI block," which can be represented as OOh, 01h, 02h, 03h, 04h, 05h, 06h, or 0'7h) of the disc information, where a fifth byte of OOh or 07h indicates a first or eighth disc information, respectively. A meaning of the sequence of the 5t-'' byte will be decided by Nth and L''' bytes that vrill be explairied later.
Plriting speed information applicable by a corresponding disc is recorded in a specific area (Nth byte) within disc information which is named 'Writing speed flag' field. For instar_ce, whether a specific writing speed~of eight kinds of writing speeds is applicable by the corresponding disc is represented by 1-bit each in the same area having 1-byte allocated thereto. Namely, it can be defined that the corresponding writing speed is not applicable (supported) if a bit value is 'Ob' in entire bits or that the corresponding writing speed is applicable (supported) if the bit value is 'Ib'. Hence, each of the bits b0-b7 within 1-byte becomes flag information indicating applicability of a specific writing speed.

. 14 For instance, if lx speed is applicable by a corresponding disc only, '0000 0001' is written in Nth byte. If all of the eight kinds of writing speeds are applicable, '1111 1111' is written in the Nth byte In the above explanation, lx and 2x speeds utilized by every disc almost are previously decided to be adopted. Yet, writing speeds decided by specification can be used as the remaining writing speeds from 3rd writing speed. For instance, the 3ra, 4th, 5th, 6eh~ 7t", and 8th writing speeds may be set to 5x, 6x, 8x, 12x, 14x, and 16x speeds, respectively.
According to the present invention, an allowable writing speed is represented by a bit having a value of "1, " and each bit having a value of "0" represents an excluded writing speed.
Hence, there can be no case of a lower bit being set to zero while an upper bit is set o one. For example, a disc allowing writing speeds up to the fourth writing speed has writing speed flag of 0000 1111b; and a writing spend flag of, say, 0000 lOllb, is barred.
For another example, bits can be independently set. Even if upper bits are set to 'lb', it is able to set lower bits to 'Ob'. In case that a lower writing speed has to be applicable if a maximum writing speed is applicable, write parameters according to the corresponding writing speed should be written altogether. Hence, it may become a considerable load put on an information recording. By rendering a portion of the lower writing speed inapplicable even if the maximum writing speed ' l5 is applicable, it is able to reduce the corresponding information amount. Furthermore, be using one specific writing parameter, at least two recording speeds can be possible.
Meanwhile, recording layer information indicating the number of recording layers) existing c'rithin the corresponding disc is recorded in another specific area (Lth byte) within the disc information, which is named 'Number of Recording Layer' field.
For instance, a value meaning the number of the recording layers) can be represented by a binary number in the same area having 1-byte allocated thereto. In case that the recording layer is the single layer in FIG. 1, '0000 0001' ~ s written in the Lth byte. In case that the recording layer is the dual layer in FIG. 2, 'DD00 0010' is written in the L,tr.
byte. In case that four re;.ording layers exist, '0000 0100' is written in the Lth byte .
. Since limitation is put on the number of the currently considered recording layer (s), which is currently two recording layers, 4-bi s within the Lth byte are enough to represent total fifteen recording layers (in case of '1111').
In such a case, it is apparent that other valid information can be written in the remaining area (4-bits) of the L~h byte.
Moreover, identification information for identifying a kind of write strategy (WS) recorded in Pth~111th bytes is written in another specific area (Mtv byte) within the disc information, which is named 'Write Strategy (WS) Type' field.

" 16 Namely, in the disc information of the present invention, one write strategy (WS) is recorded for a specific writing speed and a specific recording layer and the write strategy is optionally selected from various kinds of specified types by a disc manufacturer. Hence, if the corresponding disc information is a first Ttype write strategy WS-1, '0000 0001' is written in the 1''h byte. If the corresponding disc information is a second type write strategy WS-2, '0000 0010' is vrritten in tha Mth byte . Substantial write strategy (P1S) is recorded in Pth-.Illt~' bytes. Yet, the substantial write strategy (WS) will be recoded as a value interoperating with the decided write strategy (WS) type in the Mth byte. The write strategy (WS) type via the Mth byte is optior_ally recordable in every disc information. It is also possible to apply one specified ~~rrite strategy (WS) type in basic speed(lx speed) disc information, which is expected to be supported by every record playbac'.~t apparatus (FIG. 8)~, in a mandatory manner.
In addition to a method of recording specific parameters of the write strategy (Tr~S), a medium property of a recording layer is generally modified by applying a laser beam to the recording layer within an optical disc via a pickup ('11' in FIG. 8) to perform a recording thereof. Hence, it should be decided an intensity (recording power) of the laser beam, a time of :applying the recording power thereto, and the like.
The above-decided various kinds of write strategies are named 'Write Strategy (WS)' in general and specific contents recorded within a specific 'Write Strategy (WS)' are named 'Write Strategy (WS) parameters'.
The crrite strategy (G7S) can' be recorded in various ways. As a disc becomes highly densified and has higher speed, a writing speed, i.e., disc RPM) as well as the medium property of the recording layer is considerably affected. Hence, a more accurate system is requested. The various 'write strategies (WS) are explained as follows for example.
First of all, there is a system having a recording pulse smaller by 1 than a recording mark size (n) formed on a recording layer medium, which may be called '(n-1) WS'.
Secondly, there is a system having a recording pulse having a size amounting to a half of the recording mark size (n) , which 1S may be called 'n/2 WS'. New write strategies (WS) keep being developed. Regarding the different kinds of write strategy (WS), when there exist the various systems of the write strategy (WS) exist as parameters applied to the write strategie s (WS) differ from each other, a disc manufacturer tests the recording power according to the write strategy (WS) to be recorded in the selected Mth byte and then records a result of the test as write strategy (WS) in the Pth~lllth bytes within the disc information.
From the above-recorded 'writing speed information' of the Ntn 2S byte and the 'recording layer information' of the Lth byte, the record/playback apparatus (FIG. 8) recognizes how many disc ' 18 information exist within the corresponding disc. Namely, t'he number of the existing disc information is found by multiplying an applicable writing speed number by the number of recording layers. As the present invention applies one write strategy (V1S) for a specific writing speed and a specific recording layer, the kind and number of the write strategy (WS) may not be taken into consideration in deciding the number of disc information.
The above-decided information about the number of total disc information can be recorded in a specific area (e.g. , 4th byte or the like) (not shown in the drawing) within the disc information as well.
rence, it is able to program .a plurality of the above-decided disc information that the sequence is decided by the sequence numbers, which is written in the 5th byte in the foregoing . description, and that each of the disc information designates the previously decided writing speed and recording layer by the sequence.
For example, by knowing that four writing speeds applicable by' a disc exist if the Nth byte is '0000 1111' and that two recording layers exist within the disc if the Lth byte is '0000 0010', total eight disc information are needed so that the sequence will be 'OOhw07h' It is previously decided that disc information of 'OOh', 'Olh', '02h', '03h', 'Oah', '05h', '06h', and '07h' relate to 'lx speed, 1St recording layer (LO)', '2x speed, 2nd recording layer (L1)', '2x speed, 1St recording layer (LO)', '2x speed, 2nd recording layer (Ll)', '3rd writing speed, 1St recording layer (LO)', '3ra writing speed, 2nd recording layer (L1)', '4th writing speed, 2nd recording layer (L1)', and '4tn writing speed, 2nd recording layer (L1)', respectively.
In the above-explained example, the writing speed is preferentially taken into consideration. Yet, it is apparent that the recording layer can be preferentially taken into consideration. Namely, it can be defined in the sequence of '1St recording layer {L0), lx speed', '1St recording layer (LO), 2x speed', and the like Hence, in order to acquire the disc ir_formation for a specific target writing speed and a specific target recording layer, the record playback apparatus (FIG. 8) is facilitated to check which disc information is related to the specific target writing speed and recording layer from 'writing speed information' of the Nth byte' and 'recording layer information' of the Lth byte commonly recorded within the respective disc information instead of playing back to 'check the entire disc information.
FIG. 4B shows an example of extending the first embodiment of the present invention in FIG. 4A. In case that writing speeds applicable by a disc exceed eight kinds, Nth byte ('Writing speed flag' field) in FIG. 4A is extended to indicate presence or non-presence of applicability of 1St to 8th writing speeds by a flag in Nlth byte ('Writing speed flag l' field), and another byte is allocated to display presence or non-presence of applicability of 9th~16th writing speeds by a flag in N2th byte.
Contents written in the remaining, bytes are equivalent to those of the first embodiment of the present invention in FIG.
4A.
5 FIG. 4C shows an example of recording disc information by the first embodiment of the_present invention in FIG. 4A. It can be known that there are two applicable writing speeds (lx and 2x) from Nth byte ('0000 OOlOb') commonly recorded in the entire disc information and that two recording layers exist 10 within a disc from Lth byte ('0000 OOlOb').
Hence, in the example of FIG. 4C, total four disc information (two recording layers multiplied by two writing speeds) exist and a sequence of the disc information beco~:aies 'OOh' (1X,L0) 'Clh' (1X,L1) ~ '02h' (2X,L0) ~ '03h' (2X,L1) . This is a 15 specified content according to a predetermined sequence and, . as mentioned in the foregoing description, can be rendered into a different sequence by a specification.
An intrinsic write strategy. (WS) is recorded in other bytes within each disc information as wel l as Nth and Lth bytes.
20 Specifically, information of a type of a write strategy (WS) written in Pth--111th bytes within the corresponding disc information is recorded in Mth byte. Namely, information in the Mth byte can be different from that in the Pth~111th bytes .
In the example in FIG. 4C, 'OOh' (lx-speed, LO) and '01h' (1x-speed, L1) relate to the application of a first type write strategy (WS-1) and '02h' (2x-speed, LO) and '03h' (2x-speed, Ll) relate to the application of a second type write strategy (ws-2 ) .
FIG. 4D shows another example of recording disc information by the first embodiment of the present invention in FIG. ~A. It car be known that there are eight applicable writing speeds ( 1 x through 8x) from N'~ byte ( ' 1111 1111b' ) commonly recorded in the entire disc information and that four recording layers exist within a disc from Lt'- byte ('0000 O100b'). Hence, in the another example of FIG: 4D, total thirty-two disc information (four recording layers multiplied by eight writing speeds) exist and a sequence of the disc information becomes 'OOh' (1X,L0) ~ 'Olh' (1X,L1) ~ '02h' (1X,L2) ~ '03h' (1X,L4) '04h' (2X,L0) ~ ... ~ '31h' (16X,L~-_) .
An intrinsic write strategy (WS) is recorded in other bytes within each disc information as well as Nth and Lth bytes.
Specifically, information of a type of a write strategy (WS) written in Pth~lllth bytes within the corresponding disc information is recorded in Mth byte. I~Tamely, information in the Mth byte can be different from that in the Pt''--111th bytes.
In the another example of FIG. 4D; if a record playback unit (FIG. 8) intends to search disc information related to 2x-speed of a first recording layer to perform recording by applying a write strategy (WS) within the corresponding disc information, it can be known from the information in the Nth and Lth bytes commonly recorded in the entire disc information that total thirty-two disc information (four recording layers . 22 multiplied by eight writing speeds) exist in the corresponding disc according to the sequence of the disc information, namely, 'OOh' (lx-speed, LO) through '3lh' (16x-speed, L4). Hence, the record playback apparatus- (FIG. 8) enables to recognize that the disc information related to the 2x-speed of the first recording layer to be searched is '04h' and that the corresponding disc information ('04h') is recorded as the first type write strategy (WS-1) from the write strategy (WS) type identification information ('0000 0002b') recorded in the Mth byte within the corresponding information ('04h'), thereby reading out parameter values of the first type carite strategy (G1S-1) via the Ptr-111th bytes ~o utilize in the recording Likewise, if intending to search disc information related to 16x-speed of a fourth recording layer to perform recording by applying a write strategy (WS) ~;rithin the corresponding disc information, the record playback unit (FIG. 8) recognizes that the corresponding disc information is '31h' via the same process and that the write strategy type (WS) is the second type (WS-2), thereby enabling to utilize them in the recording.
Therefore, if a host or a control unit ('20' in Fig. 8) requires the recording in a specific recording layer at a specifis writing speed; the record playback apparatus (FIG. 8) is facilitated to search the corresponding information, thereby enabling to confirm the write str-ategy (WS) recorded within the corresponding disc information.

' 23 FIG. 5A shows a method of recording disc information according to a second embodiment of the present invention. In order to search disc information related to a specific writing speed and recording layer like the first embodiment of the present invention in FIG. aA, writing speed information ('writing speed flag' field) applicable by a disc is recorded in Nth byte and recording layer information ('Number of Recording Layer' field) existing within the disc is recorded in L'h byte. A
second embodiment according to the present invention is characterized in that intrinsic recording layer information and writing speed information of the corresponding disc information are additionally recorded in a corresponding specific area (7t' byte) Namely, in the same manner of the first embodiment of the present invention in FIG. ~A, after the disc information for the specific writing speed and recording layer has been searched, the recording layer information and the writing speed information corresponding to each' disc information are directly recorded in each disc information to confirm (verify) whether the search disc information is related to the requested specific writing speed and recording layer. This is necessary for coping with error detection of the disc information since the disc information is very important for recording and management of the disc. Moreover, if the intrinsic writing speed and recording layer information are directly recorded in the di c information each, the method of . 2~
searching the disc information quickly like in the first embodiment of the present invention can be programmed as well as the method of searching the disc information using the 7t byte only according to the second embodiment of the present invention in aspect of designing the record playback apparatus (FIG. 8). Hence, it is advantageous in that a degree of ,-freedom can be given to the design thereof.
In the second embodiment (FIG. 5A) , the Nth, Lth Mth and P--111th bytes have the same content as described in the first embodiment (Fig. 4A). The characterizing 7th byte ('Speed information for Layer' field) is divided into upper 4-bits b0~b3 where writing speed information {speed info) is recorded and lower 4-bits b4-:b7 where recording layer information (Layer info) is recorded. Unlike the information recorded in the Nvh and Lth bytes, the, writing speed information and the recording layer information mean an intrinsic value of the corresponding disc information.
For instance, in order for the upper 4-bits b0~b3 of the 7th byte to represent maximum 16x speed, it is defined that 'OOOOb', '0001b', and '1111b' mean 1x-speed, 2x-speed, and 16x-speed, respectively. The lower 4-bits of the 7th byte is rendered to directly display a value of the recording layer.
It is defined that'OOOOb', 'OOOlb', and 'llllb' mean lst recording layer L0, 2nd recording layer Ll, and 16th recording layer L15, respectively.

. 25 Hence, if the corresponding disc information is the 2x-speed associated information of the second recording layer, the byte becomes '0001(L1) 0001(2x)'.
FIG. 5B shows an example of recording disc information according to the second embodiment of the present invention in FIG. 5A, in which total thirty-two disc information exist by four recording layers and eight writing speeds.
FIG. 5B is different from FIG: 4D in that the 7th byte within each of the disc information possesses the intrinsic writing speed information and recording layer values of the corresponding disc information but is equivalent to FIG. 4B in that the remaining portions (field) within the disc information are equal to those in FIG. 4D.
Hence, the 2x-speed associated disc information of the 1St recording layer enables to inform that the disc information of 04h' corresponds to it using the Nth and Lth bytes like the example of FIG. 4D. Yet; in FIG. 5B, it is confirmed (verified) that the corresponding disc information ('04h') coincides with the disc information for the requested specific writing speed and recording layer from '0000(LO) 0001(2x)' written in the 7th byte within the corresponding disc information ('04h').
FIGS. 6A to 6C are diagrams of recording disc information according to a third embodiment of the present invention, in which a disc manufacturer enables to optionally record a specific one among a plurality of write strategy (WS) kinds to secure disc manufacturer's convenience and to enable an efficient recording of disc information.
Specifically, a third embodiment according to the present invention is characteri2ed in that, in recording various kinds of write strategies (hTS) within disc information, the write strategy (WS) kinds amounting to a per writing speed specific number (e.g., m, where m<n) among the various kinds (e.g., n-kinds) of the write strategies (WS) specified for disc manufacturer's (or disc information writer's) convenier_ce are optionally recordable only and that, for convenience of a manufacturer developing an optical record playback apparatus (FIG. 8) performing an optica l recording using the a.bove-recorded disc information, information indicating which is an optimal write strategy (WS) among a plurality (m) of write strategies (WS) recorded within the disc information is recorded within the disc information.
A method of recording disc information according to a third embodiment of the present invention is explained by referring to FIGS. 6A to 6C as follows.
2o FIG. 6A schematically shows fields recorded within disc information.
Referring to FIG. 4A; a sequence for disc information each is decided by a sequence number and is recorded by 1-byte. For instance, the information is recorded in a 5th byte within disc information, is named 'DI frame sequence number in DI block', and is briefly represented by 'OOh, Olh, , 02h, ...~ . Namely, if the information of the 5th byte is 'OOh', it means 1St disc information. If the information of the 5th byte is '07h', it means 8th disc information.
Writing speed information applicable by a corresponding disc S is recorded in a specific area (Nth byte) within disc information, which is named 'Writing speed flag' field. For instance, whether a specific writing speed of eight kinds of writing speeds is applicable by the corresponding disc is represented by 1-bit each in the same area having 1-byte allocated thereto. Namely, it can be defined that the corresponding writing speed is not applicable (supported) if a bit value is 'Ob' in entire bits or that the corresponding writing speed is applicable (supported) if the bit value is 'lb'. Hence, each of the bits b0~b7 ;~rithin 1-byte becomes flag information indicating applicability of a specific writing speed. For instance, if lx speed is applicable by a corresponding disc only, '0000 OOOlb' is written in Nth byte.
If all of the eight kinds of writing speeds are applicable, '1111 1111b' is written in the Nth byte.
In the above explanation, lx speed (1X) and 2x speed (2X) utilized by every disc almost are previously decided to be adopted. Yet, writing speeds decided by specification can be used as the rest writing speeds from 3ra writing speed. For instance; it is possible to set 3rd, 4th, 5th 6tn, 7th and gth writing speeds (3rd X, ~th X~ Stn X~ 6th X, 7th X, 8th X) to 5x, 6x, 8x, 12x, 14x, and 16x speeds, respectively.

And, information of informing a kihd of write strategy (WS) applicable by a specification of a corresponding disc is recorded in another specific area (Ltn byte) within the disc information, which is named 'Write Strategy (WS) flag' field.
For instance, whether a specific unite strategy (WS) of eight kinds of write strategies (WS) is applicable by the corresponding disc is represented by l-bit each in the same area having 1-byte allocated thereto.
Namely, it can be defined that the corresponding write strategy (WS) is not applicable (supported) if a bit value is 'Ob' in entire bits or that the corresponding write strategy (WS) is applicable (supported) if the bit value is '1-b'. Hence, each of the bits b0~b7 within 1-byte becomes flag information indicating applicability of a specific write strategy (WS).
For instance, if 15t to 3rd type write strategies (WS1 to WS3) are applicable by a corresponding disc only, '0000 OOOlb' is written in Lth byte. If all of the: eight types of write strategies (WSl to WS8) are applicable, '1111 llllb' is written in the Lth byte .
In doing so, a setup state of lower bits is not decided according to a setup state of upper bits. Instead, the lower bits are independently set, respectively. For instance, if the 1St and 3rd type write strategies WS1 and WS3 are applicable but the 2nd type write strategy WS2 is inapplicable, the Lth byte will be set to '0000 OlOlb'.

Meanwhile, recording layer information indicating the number of recording layers) existing within the corresponding disc is recorded in another specific area (Mth byte) within the disc information, which is named 'Number of Recording Layer' field.
For instance, a value meaning the number of the recording layers) can be represented by a binary number in the same area having 1-byte allocated thereto. In ease t'_~.at the recording layer is the single layer (one recoding layer) in FIG. 1, '0000 OOOlb' is written in the Mth byte. In case that the recording layer is the~dual layer (two recording layers) in FIG. 2, '0000 OOlOb' is ~~~ritten in the M'h byte. 1n case that four recording layers exist, '0000 O100b' is written in the Mth byte .
And, parameters of a selected write strategy (WS) are vrritten in another specific area (P-"~111th bytes) within the disc information, which is named '~~rite Strategy (WS) parameters' field.
By writing the N'h, Lth, and Mth byte ~ information recorded .vithin the disc information by the same values in common to the entire disc information, respectively, the record playback apparatus (FIG. 8) is facilitated to acquire the in~ormation of the writing speed applicable by the corresponding disc, the vrrite strategy (rrlS) kind, and the number of the recording layers despite playing back any disc information. And, from the acquired information, the record playback apparatus (FIG.
8) enables to decide a sequence of the disc information recorded within the disc, the writing speed and recording layer meant by the sequence, and the corresponding write strategy (WS) kind ar type.
FIG. 6B shows an example of recording disc information 5 according to the third embodiment of the present invention in FIG. 6A, in which three kinds-of writing speeds are applicable ,_ so that Nth byte becomes ' 0:000 Oll lb' , in which four kinds of write strategies (WS) are applicable sb that Lth byte becomes '0000 1111b', and in which two recording layers exist within a 10 disc so that Mth byte becomes '0000 OOlOb'.
Hence, it may be able to record disc information per writing speed, per recording layer, and per write strategy (WS) type.
Yet, in such a case, the number of the recorded disc information excessively increases. Moreover, a disc 15 manufacturer should test the entire write-strategy (WS) types and record the test results within the disc information, whereby it becomes a burden:
Therefore, in the third embodiment according to the present invention, write strategies (WS) of which number (m) is 20 smaller than that (n) of the maximum applicable write strategy types are recordable within disc information and a disc manufacturer further enable to optionally record a specific one of a plurality of write strategies (WS); whereby disc manufacturer's convenience is secured'as well as an efficient 25 recording of disc information is enabled.

, 31 .
FIG. 6B shows a recording example using lst and 2nd type write strategies WS1 and WS2 for 1x speed (1X), lst and 2nd type write strategies WS1 and WS2 for 2x speed (2X) , and 2nd and 3rd type write strategies WS2 and WS3 for 3rd writing speed (3rd X) .
Namely, it is able to record disc information using write strategy (WS) types (kinds) of which number (two) is smaller than that (four) of the entire applicable write strategy (P7S) types ( kinds ) .
Specifically, regardless of the number of the applicable write strategy (WS) types, a disc manufacturer preferably selects two of the applicable write strategy (WS) types to perform recording per writing speed. Thus, a degree of freedom of optional recording is secured for the disc manufacturer as well as the number of disc information recorded within a disc can be appropriately adjusted.
FIG. 6C shows another exart~ple of recording disc information according to the third embodiment of the present invention in FIG. 6A. Like FIG. 6B, there are three kinds of applicable writing speeds and Nth byte is set to '0000 0111b'. There are four applicable write strategy (WS) types and Lth byte is set to '0000 1111b'. There are two recording layers existing within a disc and M'h byte is set to '0000 OOIOb'.
Specifically, in FIG. 6C, a specific write strategy (WS) is recorded in a mandatory manner in case of lx speed (1X) or the write strategy (WS) can be recorded in an optional manner in case of the rest writing speeds.

. 32 Namely, in case of recording tu~o kinds of write strategy (WS) types per writing speed, ist type write strategy WS1 is preferentially recorded in. a mandatory manner in case of 1x speed (1X) and one of 2nd to 4th type write strategies S~1S2 to S WS4 is optionally selected 'to be recorded. In Fig. 6C, the 2na type write strategy WS2 is selected to be recorded.
Moreover, in 2x speed (2X) or 3ra writing speed (3-d X) , without the above-explained limitation; taro of the four kinds of write strategies WS1 to WS4 are selected to be recorded:
The specific write strategy (G~IS) is recorded for the 1x speed in a mandatory manner. This is to enable a manufacturer or developer of a record playback apparatus (FIG. 8) to develop low-price products coping with one specific ~~rrite strategy (WS) only as well as products coping with the entire write 1~ strategy (~dS) types, thereby facilitating to various kinds of products.
Hence, the writing speed allocating the write strategy (VAS) in a mandatory manner can be set to such ~a higher speed as 2x speed and the like instead of lx speed in specific specifications. And, it is apparent that the tecL~.nical idea of the present invention is simply extended to such an application according to the technological development.
FIG. ?A and FIG. 7B are diagrams of recording disc information according to a fourth embodiment of the present invention, in which disc information structures are schematically shown. The fourth embodiment oz the pre ent invention is characterized in that a disc manufacturer records information indicating which is an optimal write strategy (WS) among a plurality of write strategy (WS) types recorded within disc information within a separate area of the disc information.
Namely, by recording the information indicating the optimal write strategy (WS), a'_ record playback apparatus (FIG. 8) enables to set up an optimal write strategy (WS) type quickly, thereby enabling to efficiently perform a recording by a command of a control unit ('20' in FIG. 8).
FIG. 7A shows a concept of recording disc information according to a fourth embodiment of the present invention, in which Nth, Ltn~ and Mth bytes explained in the third embodiment of the present invention mean the same contents and in which information indicating an optimal write strategy (i~7S) among a plurality of write strategy (WS) types is additionally recorded in Qth byte Referring to FIG. 7A, Qth byte of disc information is named 'Best WS flag in writing speed' field and the corresponding byte indicates what is an optimal write strategy (WS) in the writing speed indicated by the disc information.
Namely, bits within the Qth byte indicates ~~rite strategy (WS) types in one-to-one correspondence, respectively to mean total eight kinds of the write strategy (WS) types. Specifically, 'b0' , 'bl' , and 'b7' mean lst, Zna~, and 8th type write strategies CSl, C~s2,and 8, respectively. If bit value WS a in the entire bits is 'lb', the write strategy (~l5)of the corresponding type becomes the optimal write strategy (WS) type within the corresponding writing speed.
Namely, one of eight bits within the Qth b~rte becomes ' lb' only, while each of the rest bit's will be 'Ob'. FIG. 7A shows that the Qth byte becomes '0000 OOlOb' if the 2nd type write strategy WS2 becomes the optimal write strategy (WS) of the ,-corresponding writing speed for example. Yet, FIG. 7A
exemplarily shows the example of representing the optimal write strategy (WS) only. And, it is apparent that the optimal write strategy (WS) type can be represented in various wads.
FIG. 7B shows an example of recording disc information according to the fourth embodiment of the present invention.
Preferring to FLG. 7B, Nth, Ltr, and Mth bytes are areas where the entire disc information record the same values in common.
'0000 O1?1b' in the Nth byte means three kinds (e.g., 1X, 2X, and 5X) of writing speeds applicable by a corresponding disc.
'0000 1111b' in the Lth byte means four kinds of write strategies (WS) , which are ls' to 4'h type write strategies WS1 to WS4, applicable by the corresponding disc. And, '0000 OOlOb' means two recording layers existing within the corresponding disc.
For example, FIG. 7B shows that the 1St and 2nd type write strategies WS1 and WS2 are elected in the 1x speed, the 1St and 2nd type write strategies WS1 and WS2 are selected in the 2x speed, and the 2nd and 3rd type write strategies WS2 and WS3 are selected in the 4x speed.

Moreover, in order to enable a record playback apparatus (FIG.
8) to set up an optimal write strategy (WS) quickly, a disc manufacturer records information indicating a type of the optimal write strategy (WS) of the corresponding writing speed 5 in Qth byte . In FIG. 7B, the Qth byte is set to ' 0000 0010b' by selecting the 2nd type write strategy WS2 as the optimal in the ,_ 2x speed or to '0000 O100b' by selecting the 3rd type write strategy WS3 as the optimal in. the 4x speed.
Hence, each of the Qth bytes within '04h~07h' as the disc 10 information related to the 2x speed will be set to the same '0000 OOlOb' and each of the Qth bytes within '08h~llh' as the disc information related to the 4x speed will be set to the same '0000 0100b' Moreover, Pth~lllth bytes within the disc' information are areas 15 for recording the write strategy (WS) meant by the corresponding disc information. Hence, the write strategy (WS) will be recorded in each of the corresponding disc information.
In FIG. 7B, '04h' as the Sth disc information writes parameters for the lst type write strategy WS1 in the Pth~111~h bytes, and 20 '11h' as the 12th disc information writes parameters for the 3ra type write strategy WS3 in the Pth~111th bytes .
In summary of the example of FIG. 7B, applicable writing speed information, applicable write strategy (WS) types, and number information of recording layers existing within a disc are 25 recorded in the Nth, Lth~ and Mth bytes, of which values are shared by the entire disc informatiozi, within the disc information, respectively. The information indicating the optimal write strategy (W7S) type in the corresponding writing speed is recorded by the same value in the Qth byte within the disc information. And, each of the disc information records parameters for intrinsic write strategy (WS? in the Pth~111t' bytes.
>-FIG. 8 is a block diagram of an optical disc record playback according to the present invention Referring to FIG. 8, a recording and/or reproducing apparatus according to the present invention includes a record/playback unit 10 carrying out recording and/or playback on an optical disc and a control unit 20 controlling the record playback unit 10.
Tndustrial Applicability Tne control unit 20 gives a recording or playback command for a specific area, and the record/playback unit 10 caries out the recording/playback for the specific 'area according to the command of the control unit 20. Specifically, the record/playback unit 10 may i:?clude an interface unit 12 performing communications with the host, or an external device, a pickup unit 11 directly recording data on the optical disc or playing back the data, a data processor 13 receiving a playback signal from the pickup unit 11 to restore into a necessary signal value or modulating to deliver a signal to be recorded into a signal to be recorded on the optical disc, a servo unit 14 reading out a signal from the optical disc correctly or controlling the pickup unit ll to record a signal on the optical disc correctly, a memory l5 temporarily storing disc control information including disc control information, and a microcomputer 16 responsible for controlling the above-described elements within the,record playback unit 10. In the above system, it is also possible to control the recording and/or reproducing of data without the control unit 20. In that case, the Microcomputer 16 may control all units in the record/playback unit 10 as performing the function of the control unit 10.
A recording process of an optical disc according to the present invention is explained in detail as follows.
First of all, once an optical disc is loaded in the optical recording and reproducing apparatus, the entire disc management information within the di c is read out to be temporarily stored in the memory l5 of t'ne record/playback unit 10. And, various kinds of the disc management information are utilized for the record/playback of the optical disc.
2o Specifically, the management information stored in the memory 15 includes disc information of the present invention. Hence, the recording layer information, writing speed information, and write strategy applicable to the corresponding writing speed recorded within the disc information are read out to be stored in the memory:

For instance, an applicable writing speed and write strategy of the loaded disc are determined based on the flag information indicating applicability of a specific writing speed and write strategy information indicating a usable cvrite strategy type and its parameters included in the management information.
If intending to perform a writing on a specific area within the optical disc, the control unit 20 renders such an intent into a writing command and then delivers it to the record/playback unit 10 together with data for writing location information to be recorded. After receiving the writing command, the microcomputer 1'o decides the corresponding writing speed applied to an intended recording layer within the optical disc from the management information stored in the memory 15 and then performs the writing command using the optimal write strategy by referring to the decided writing speed.
Accordingly, the present invention provides various methods of providing disc control information coping with higher writing speed in a high-density optical disc; thereby enabling to uniformly apply the standardized :disc control information to efficiently cope with the record/playback of the optical disc.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims

1. A method of recording a control information for a recording medium, comprising steps of:
providing at least one control information, the control information provided per applicable writing speed to each of the at least one or more recording layers, the control information including applicable recording speed information; and recording the control information on a specific area of the recording medium.

2. The method of claim 1, wherein the applicable recording speed information included in the control information indicates presence or non-presence of applicability to each writing speed.

3. The method of claim 1, wherein the applicable recording speed information is set to allow a lower writing speed if a higher writing speed is allowed.

4. The method of claim 1, wherein the applicable recording speed information is set to a value whether or not a recording speed is applicable.

5. The method of claim 4, wherein the applicable recording speed information is set to a value in bit position.

6. The method of claim 5, wherein a lower recording speed in the applicable recording speed information is set to a value depending upon an applicability of a higher recording speed.

7. The method of claim 1, wherein information of a number of the recording layers existing within the recording medium is further included in within the control information.

8. The method of claim 1, wherein write strategy type information and write strategy parameters to be applied to the write strategy type information are further included in within the control information.

9. The method of claim 1, wherein applicable write strategy type information is further included in within the control information.

10. The method of claim 9, wherein best write strategy type information appropriate for the corresponding layer and the corresponding writing speed among applicable write strategy types is further included in the disc control information.

11. The method of claim 9, wherein the write strategy information included in the control information is divided into basic write strategy information and optional write strategy information.

12. The method of claim 1, wherein intrinsic recording layer information and writing speed information meant by the corresponding control information are further included in the control information.

13. The method of claim 1, wherein the specific area is a management area of the recording medium , the management area is a preloaded area on manufacturing of the recording medium or a copied area to a recordable area from the preloaded area.

14. The method of claim 13, wherein the control information is disc information (DI) configured in a PIC
(permanent information and control data) area in Blu-ray disc.

15. The method of claim 13, wherein the control information is physical format information.

16. A data structure for indicating recordable speed information, characterized in that the recordable speed information includes a respective recording speed flag to indicate whether a corresponding speed is applicable or not, and a first speed flag for a fist recording speed lower than a second recording speed is set to be dependent on a second speed flag for the second recording speed.

17. The data structure of claim 16, wherein the first speed flag is set to indicate that the first recording speed is applicable when the second speed flag indicates that the second recording speed is applicable.

18. The data structure of claim 16, wherein recording parameters for the applicable recording speed are further included.

19. The data structure of claim 18, wherein the recording parameters includes a write strategy type for at least one recording speed.

20. The data structure of claim 19, wherein the recording parameters includes a write strategy parameters for the write strategy type for the recording speed.

21. The data structure of claim 20, wherein the recording parameters is provided to a specific recording layer.

22. The data structure of claim 16, wherein each of the first and second speed flags is indicated by one bit.

23. A method of recording data on an optical recording medium, comprising the step of recording speed information on a specific area of the optical recording medium, wherein the speed information includes a respective recording speed flag to indicate whether a corresponding speed is applicable or not and wherein a first speed flag for a fist recording speed lower than a second recording speed is set to be dependent on a second speed flag for the second recording speed.

24. A method of recording/reproducing data on/from an optical recording medium, comprising the steps of:
reading speed information from a specific area of the optical recording medium, wherein the speed information includes a respective recording speed flag to indicate whether a corresponding speed is applicable or not and wherein a first speed flag for a fist recording speed lower than a second recording speed is set to be dependent on a second speed flag for the second recording speed; and recording data on a main data area of the optical recording medium based on the read speed information.

25. The method of claim 24, wherein the first speed flag is set to indicate that the first recording speed is applicable when the second speed flag indicates that the second recording speed is applicable, whereby the data is recorded based on the speed information.

26. The method of claim 24, wherein the recording step records data using an applicable recording speed indicated by a recording speed flag.

27. The method of claim 24, wherein the applicable recording speed is highest recording speed indicated by a recording speed flag.

28. The method of claim 24, further comprising :

reading write strategy information from the specific area of the optical recording medium, and recording data on the main data area based on the read speed information and write strategy information.

29. The method of claim 28, wherein the recording step records the data on the main data area of a specific recording layer.

30. The method of claim 28, wherein the recording step records data on the main data area using best write strategy type for the recording speed.

31. A recording medium having speed information, characterized in that the speed information includes a respective recording speed flag to indicate whether a corresponding speed is applicable or not and in that a first speed flag for a fist recording speed lower than a second recording speed is set to be dependent on a second speed flag for the second recording speed.

32. The recording medium of claim 31, wherein the first speed flag is set to indicate that the first recording speed is applicable when the second speed flag indicates that the second recording speed is applicable.

33. The recording medium of claim 32, wherein each of the first and second speed flags is indicated by one bit.

34. The recording medium of claim 33, wherein the recording medium is a recordable DVD.

35. The recording medium of claim 33, wherein the recording medium is a recordable Blu-ray disc.

36. An optical disc comprising at least one recording layer provided with a recordable area and a recording-disabled or prerecorded area, wherein disc control information is separately recorded within the prerecorded area per the recording layer and wherein applicable recording speed information and write strategy information according to a corresponding writing speed are recorded within the disc control information.

37. The optical disc of claim 36, wherein the write strategy information indicates whether a corresponding write strategy type is applicable.

38. The optical disc of claim 36, further comprising a flag indicating a preferable one of a plurality of write strategy types.

39. The optical disc of claim 36, wherein the write strategy information includes a (n-1) write strategy type where 'n' is a length of bit.

40. The optical disc of claim 36, wherein the write strategy information includes a n/2 write strategy type where 'n' is a length of bit.

41. The optical disc of claim 36, wherein the disc is a recordable Blu-ray disc.

42. The optical disc of claim 36, wherein the disc is a recordable DVD.

43. An optical disc recording method comprising the steps of:
reading disc control information written within a management area of the optical disc per writing speed and reading to store applicable recording speed information recorded within the disc control information and write strategy information corresponding to a specific writing speed;
deciding the writing speed of the corresponding recording layer by referring to the stored speed information and write strategy information; and performing recording of data at the decided writing speed.

44. An optical disc recording/playback apparatus comprising:
a pickup unit reading or writing data ; and a controller controlling a recording in a manner of controlling the pickup unit to read disc control information recorded within a management area of an optical disc per writing speed, the control information including applicable recording speed information and write a strategy information corresponding to a specific writing speed, wherein the applicable speed information is determined by an information for indicating an applicable recording speed, deciding a recording speed of a corresponding recording layer based on the read information, and controlling recording at the decided recording speed.