AU2005202347B2 - Recording medium with a linking area including a synch pattern thereon and apparatus and methods for forming, recording, and reproducing the recording medium - Google Patents

Description

P/00/011 Regulation 3.2 AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Invention Title: Recording medium with a linking area including a synch pattern thereon and apparatus and methods for forming, recording, and reproducing the recording medium The following statement is a full description of this invention, including the best method of performing it known to us: DESCRIPTION RECORDING MEDIUM WITH A LINKING AREA INCLUDING A SYNCH PATTERN THEREON AND APPARATUS AND METHODS FOR FORMING 5 RECORDING, AND REPRODUCING THE RECORDING MEDIUM 1. TECHNICAL FIELD The present invention ~relates to structure of a linking area formed between data sections on a high-density read-only recording medium in order to be compatible with a rewritable 10 recording medium in reproduction. 2. BACKGROUND ART A disc-type recording medium such as a. compact disc (CD) can store high-quality digital- audio data permanently,- so- that it is very popular recording medium. Moreover, a: digital 15 versatile disc (referred- as 'DVD' hereinafter) has been developed as a new disc-type recording medium. A- DVD can -store much larger size than a CD, thus, high-quality moving picture or audio data are. recorded. on a DVD for much longer time. Therefore, a DVD is being used-widely. There are three types of 20 a DVD, DVD-ROM for read-only, DVD-R for write-once, and DVD-RAM or DVD-R/W for rewritable. Recently, a high-density rewritable recording. medium, called BD-RE (Blu-ray Disc REwritable), larger in storage capacity than . a DVD is being standardized among concerned 25 companies. As shown in. Fig. la, a 'rewritable disc, BD-RE' has divided areas composed of a. clamping area 1, a transition area 2, a burst cutting area (BCA) 3, a lead-in area 4, a data zone, and 1A a lead-out area 5. The clamping area 1 is a .center azea- to be clamped by a camper of disc device to fix a rotating disc, and the transition area 2 is an area between the clamping area 1. and 5 the information area including the -lead-in area 4 and the data zone. The BCA 3 'is. used to add information to the disc after completion of a disc manufacturing process. The lead-in area 4 is where important information needed to disc reproduction while the lead-out area 5 is where disc ending signal, is 10 written. The lead-in area 4 is subdivided into several areas of the ,first guard, PIC, the second guard, the second information, OPC, reserved, and the first informat.on. The first guard area is ^ meant as a protection area 15 against overwriting of the PIC area by the BCA, the PIC area is an area where general information about the disc and -various other information has been stored in the pre-recorded groove, the second guard area is meant as a buffering area for the changeover from the pre-recorded area to the rewritable area, 20 and the first and the second information area are respectively used to store specific information about disc or application, such as e.g. control information. Figs. lb and ic show an - RUB (Recording Unit Block) def ined in the disc standard under discussion. A -single RUB, 25 whidh is corresponding to a single ECC (Error Correction Code) block, is composed of Run-in, physical cluster, Run-out, and guard area, as shown in Fig. lb. If many RUBs, namely, successive RUBs are created at a -time to store real-time input data, e.g., A/V data, the set of Run-in, physical and Run-out 30 is* created repeatedly as many as necessary and a guard area 'Gurar_3' is formed at the end, as shown in Fig. 1c. The Run-in, as shown in Fig. 2a, consists of a 1100 2 channel-bit guard 'Guard_1' and a 1660-channel-bit preamble 'PrA' . 55 repetitions of a 20-channel-bit pattern are written in the guard 'Guard_1' to indicate the head of an RUB while the first sync data 'Sync._1' and the second sync data 'Sync_2', 5 which are 30 .channel bits in length, are written in the preamble -'PrA'. Each sync data is composed of 24-bit sync body and 6-bit sync ID. The sync IDs of the first and the second sync data are '000 100' (FS4) and '010 000' (FSG), respectively. The Run-out, as shown in Fi'g. 2b, is composed of- a 540 10..channel-bit guard 'Guard2' and a 564-channel-bit post-amble 'PoA' including the third sync data 'Sync_3' . The third sync data also consists of 24-bit sync- body and 6-bit sync ID. The sync ID of the third is '000 001'(FSO). The guard 'Guard_2' is created to prevent overlap -between 15 previously-recorded data and new data to be recorded and it has 27,.repetitions of a 20-channel-bit- pattern to indicate- the end of a previously-recorded area, *namely, a just-recorded RUB. User data is written in the physical cluster and it is restored :to original data by a signal processor that uses a 20 clock' synchronized with sync. data written in the Run-in. Fig. id shows detailed recording format of a physical' cluster of a BD-RE where 31 recording frames (frames #0~#30) are recorded.. The mutually-different 7 frame syncs (FSs #0 to #6) are written in the 31 recording frames in a predetermined 25 unique order, as shown in Fig. id. Fig. le shows types and patterns of frame syncs to- be written in a physical cluster'. As shown in. Fig. le, -total 7 frame syncs are used and each frame sync is composed of 24-bit sync body and 6-bit sync identifying pattern which is. different 30 among 7 frame syncs. Each - RUB, corresponding to a single ECC block as aforementioned, has physical address information, 'e.g., address 3 unit! number (AUN) to enable *random access of an arbitrary .RUB written on a BD-RE. The physical address information is written in O physical* cluster of an RUB after .modulated and encoded. along with A/V data. And, .an AUN is derived from physical 5 sector number .(PSN) that has not-.been written actually on a BD In case.of a write-once and'.a rewritable disc (DVD-R, -RW, -RAM, +R, +RW) , a. linking frame is created behind a* previously recorded area before new data- is recorded in discontinuity with 10 the previously-recorded data. However, a read-only disc such as DVD-koM and video CD. need not any linking frame to link- two data- sections because it contains-completely-recorded data*. Such a difference between a writable and a read-only disc demands an ordinary disc player such as a DVD-player and. DVD 15 ROM drive to .equip with' additional. hardware and/or software to - play. back the both types of discs. Needless to say, .a disc device capable of recording/reproducing a writable disc also has to equip. with. additional hardware and/or software to play back a read-only 20 disc: as well -as a writable disc. In the meantime, the standard of -a high-density read-only recording medium, called 'BD-ROM',. is also under discussion .together with the standardization -of a BD-RE. By the way, if the 'physical format of a BD-ROM was to be same with a BD-RE a 25 disc: player would have the advantage to apply same reproduction algorithm to both recording media. In addition, there is necessity that they are distinguished as well as that their - forniat compatibility is guaranteed. Therefore, it is necessary to harmonize~ these mutually contrary conditions. .Nevertheless, 30 suitable harmonizing solutions are not provided yet. 4 It is not admitted that any of the information in this specification is common general knowledge, or that the person skilled in the art could reasonably be expected to have ascertained, understood, regarded it as relevant or combined it in anyway at the priority date. 3. DISCLOSURE OF INVENTION 5 It is an object of at least a preferred embodiment of the present invention to provide a read only recording medium that has the same physical recording format including a linking area in order to guarantee reproduction compatibility with a high-density rewritable recording medium, and to provide a method and apparatus for reproducing said read-only recording medium. It is another object of at least a preferred embodiment of the present invention to provide a 0 read-only recording medium with sync data in a linking area whose bit pattern is different from sync data written in data recording area, and to provide a method and apparatus for reproducing said read-only recording medium. It is another object of at least a preferred embodiment of the present invention to record a physical address in a linking area along with a frame sync. 5 It is another object of at least a preferred embodiment of the present invention to provide a read-only recording medium with a linking area where scrambled data is written, and to provide method and apparatus for reproducing said read-only recording medium. It is another object of at least a preferred embodiment of the present invention to provide a read-only recording medium whose linking area includes data scrambled the same manner as main 20 data, and to provide method and apparatus for reproducing said read-only recording medium. It is another object of at least a preferred embodiment of the present invention to provide a read-only recording medium whose linking area includes data scrambled by using values derived from physical sectors associated with data frames within a previous physical cluster, and to provide method and apparatus for reproducing said read-only recording medium. 5 It is another object of at least a preferred embodiment of the present invention to provide a read-only recording medium including dummy data in its linking areas, and to provide method and apparatus for reproducing said read-only recording medium. It is another object of at least a preferred embodiment of the present invention to provide a 5 read-only recording medium whose linking area includes data recorded in an error-recoverable format, and to provide method and apparatus for reproducing said read-only recording medium. A read-only recording medium and reproducing method and apparatus thereof in accordance with the present invention may be characterised in that a linking area is created at an area corresponding to Run-in and Run-out area of a rewritable recording medium. 10 In accordance with a first aspect of the present invention, there is provided a recording medium, comprising: a data area including at least two data sections and at least one sync signal; and a linking area to link neighboring data sections, the linking area including at least two frame sync signals, where values of the at least two frame sync signals maintain uniqueness, 15 wherein a frame in one of the data area and the linking area is identifiable based on a combination of a frame sync signal of the frame and a frame sync signal of a preceding frame, wherein the recording medium is a read-only recording medium and wherein a writing order of the two frame sync signals is different from a writing order of sync signals included in a corresponding linking area of a writable recording medium. 20 Preferably, a predetermined-sized recording frame is written in the linking area. Preferably, useful information is written in the recording frame. Preferably, a linking area is formed every junction between recorded data sections wherein each linking area includes at least one sync signal indicative of linking area. 6 Preferably, the sync signal written in a linking area is different from a sync signal written in the data section. Preferably, each of the linking areas includes data scrambled by a physical address written adjacently before or after the linking area. 5 Preferably, the linking area includes data scrambled by a frame sync written therein. Preferably, the linking area includes data scrambled by an arbitrary pre-defined value. Preferably, dummy data is recorded in a recording frame within a linking area. Preferably, information indicative of physical address is also written in the recording frame. Preferably, user data is written in the form of ECC block in the recording frames. 10 Preferably, data is written in the recording frames within the linking area after processed in the same or similar manner as user data in a data frame is done. Preferably, a certain area of data area, where an RUB is to be written, corresponding to Run in and Run-out area of a rewritable recording medium is written with a predetermined-sized recording frame. 15 Preferably, a certain area corresponding to Run-in and Run-out area of a rewritable recording medium is written with predetermined-sized recording frames, wherein a frame sync having a unique bit pattern is written in at least one recording frame. Preferably, a certain area of data area, where an RUB is to be written corresponding to Run in and Run-out area of a rewritable recording medium is written with predetermined-sized recording 20 frames where a frame sync having a unique bit pattern is twice or more. Preferably, a certain area of data area, where an RUB is to be written, corresponding to Run in and Run-out area of a rewritable recording medium is written with predetermined-sized recording frames, wherein a frame sync having a unique bit pattern is written in at least one recording frame. 7 In accordance with a second aspect of the present invention, there is provided a method of forming a recording medium, comprising: forming a linking area to link neighboring data sections of a data area while recording data onto the recording medium, the linking area including at least two linking frames; 5 selecting values of at least two frame sync signals, to maintain uniqueness; and writing the at least two frame sync signals in the linking area to link the neighboring data sections, wherein the data area includes at least one sync signal which is different from the at least two frame sync signals included in the linking area, and a frame in one of the data area and 10 the linking area is identifiable based on a combination of a frame sync signal of the frame and a frame sync signal of a preceding frame, wherein the recording medium is a read-only recording medium and wherein a writing order of the two frame sync signals is different from a writing order of sync signals included in a corresponding linking area of a writable recording medium. 5 In accordance with a third aspect of the present invention, there is provided a method of reproducing data from a recording medium, comprising: utilizing a linking area, including at least two frame sync signals, which maintain uniqueness and link neighboring data sections of a data area, to reproduce the data, wherein the data area includes at least one sync signal which is different from the at 20 least two frame sync signals included in the linking area, and a frame in one of the data area and the linking area is identifiable based on a combination of a frame sync signal of the frame and a frame sync signal of a preceding frame, wherein the recording medium is a read-only recording medium and wherein a writing order of the two frame sync signals is different from a writing order of sync signals included in a 25 corresponding linking area of a writable recording medium. 8 In accordance with a fourth aspect of the present invention, there is provided a method of recording data on a recording medium, comprising: utilizing a linking area, including at least two frame sync signals, wherein the at least two frame sync signals maintain uniqueness and are different from a sync signal included in a 5 data area, to record the data, wherein a frame in one of the data area and the linking area is identifiable based on a combination of a frame sync signal of the frame and a frame sync signal of a preceding frame, wherein the computer-readable medium is a read-only recording medium and wherein a writing order of the two frame sync signals is different from a writing order of sync signals 10 included in a corresponding linking area of a writable recording medium. In accordance with a fifth aspect of the present invention, there is provided an apparatus for reproducing a recording medium, comprising: an optical pickup configured to read data of a linking area, which links neighboring data sections of a data area and includes at least two frame sync signals, wherein values of the at least 15 two frame sync signals maintain uniqueness; and a control unit configured to determine whether a currently read position is within the linking area based on a combination of a frame sync signal of a frame and a frame sync signal of a preceding frame read by the optical pickup, and to control a reproduction according to a result of the determination, 20 wherein the recording medium is a read-only recording medium and wherein a writing order of the two frame sync signals is different from a writing order of sync signals included in a corresponding linking area of a writable recording medium. Preferably, the recording method records predetermined-sized recording frames in a certain area corresponding to Run-in and Run-out area of a rewritable recording medium, and further 25 records useful information in user data spaces of the recording frames. 8a Preferably, the recording method records a recording frame, which includes a sync, a physical address and user data, in a linking area corresponding to Run-in and Run-out area of a rewritable recording medium, wherein the user data is scrambled by one of the sync and the address included therein, a preset value, and an AUN written in a physical cluster closest to the recording 5 frame. Preferably, the recording method records recording frames, each including a sync, a physical address and user data, in a linking area corresponding to Run-in and Run-out area of a rewritable recording medium, and further records different preset dummy data in a user data space of each recording frame. l0 As used herein, except where the context requires otherwise the term 'comprise' and variations of the term, such as 'comprising', 'comprises' and 'comprised', are not intended to exclude other additives, components, integers or steps. 4. BRIEF DESCRIPTION OF DRAWINGS The above features and other advantages of the present invention will be more clearly 15 understood from the following detailed description taken in conjunction with the accompanying drawings, in which: Fig. I a shows the structure of a rewritable disc BD-RE (Blu-ray Disc REwritable); Figs. lb and Ic show respective formats of a recording 8b unit- block of a-BD-RE; Fig. id shows the structure of a physical cluster of a BD-RE; Fig. le Shows frame. syncs used for a BD-RE; 5 Figs. 2a and 2b show respectively Run-in and Run-out area included in a recording unit block of .a BD-RE; Figs. 3a and 3b show respective formats of Run-in and Run-out' area formed in a recording unit block of a - BD-ROM in accordance with the first.embodiment of the present invention; 10 Fig. 4a shows format of a linking area structured in a BD-ROM in accordance with the second embodiment of the present invention Fig. .4b shows format of a linking area structured in a BD-ROM in accordance with the third embodiment of the present 15 invention; Fig. 4c shows format of a linking area structured in a BD-ROM in accordance with the fourth embodiment of the present invention; Fig.' 4d 'shows format of a linking area structured in a 20 'BD-ROM in accordance with the fifth embodiment of 'the .present invention; Fig. 5 shows new frame~ syncs defined' in accordance with the present invention; Fig. 6a shows the structure of a linking -area tio link 25 physical clusters that is 'formed on a .BD-ROM and applicable frame syncs in accordance with an embodiment of the present invention; Fig. 6b illustrates frame syncs to be used for linking frames in accordance with the present invention;. 30 Figs. 7a to 7c show respective structures of each linking frame in a linking area and -illustrate frame syncs written therein in accordance with the present invention; .9 Fig. 7d is a conversion table of 17PP 'modulation; Fig. 8 is. a flow diagram'to-reproduce each linking frame .in accordance with the. present invention; Fig. 9 -is a simplified block diagram~of a' player to play 5 a recording medium; Figs. 10a to 10c show schematically. respective manners to write a physical address in a linking area -in accordance with the present invention; Fig. lla' is a block diagram of a linking frame 10 constructing circuitry to create a linking frame with input user data as structured in Fig. 4a; Fig. 11b~ is a block diagram of a linking frame constructing circuitry to create a. linking frame with input user data as- structured in Fig. 4d; 15 . Fig. 12a shows structure of a physical address allocated .in the linking frame structured as Fig. 4b; Fig. 12b is a detailed block diagram of a- scrambler to scramble user data into the linking- 'frame structured as Fig. 12a; 20 Fig. 13 is a detailed block diagram of a scrambler to scramble .user data -into the. linking frame. structured as Fig. 4c; Figs. 14a to 14c illustrate individually user data spaces of .inking frames where user data of . arbitrary values are 25 written; Fig. 15a shows an embodiment of the present invention to write .user data in - error recoverable format in a. user. data space of a linking frame structured as.Fig. 4d; Fig. -15b shows a useful data recording. case in the ECC 30 forrhat in the embodiment of Fig. 15a; Fig. 1Sc shows a small-sized useful data recording case in the ECC format in the embodiment of Fig. 15a; and - - . -10 Fig. 16 shows another embodiment- to write user data in error recoverable format in ~a user data space of a linking frame according to the present invention. 5. -MODES FOR CARRYING OUT THE INVENTION 5 In order that the invention may be fully understood, preferred embodimehts thereof will now be described with -reference to the accompanying drawings.. First, a linking area of a high-density recording medium structured in accordance with the present invention and data 10 recording manners related with the linking area, namely, data forming manners are explained in'detail. Hereinafter,. the terms of write'e, 'record' and 'form' are used to represent same meanings for a read-only recording medium. And, a frame formed 'in the linking area is called 15. linking frame.or recording frame. (1) Structure of a linking area A high-density real-only recording medium, e.g., -'a BD-ROM structured in accordance with the present inyention. has a . 20' physical format (composed of Run-in, physical cluster, :Run-out, and. guard) that was described with reference to. Figs.- 1 and 2 for a high-density rewritable recording medium. However, The respective fields of a BD-ROM corresponding to the .format elements of a rewritable recording medium can be named 25 differently. The Run-in formed by the first embodiment of the .present invention is, as shown in' -Fig. 3a, composed of -a guard 'Guard_1' and a preamble 'PrA' that includes two sync data. Each sync data consists of .24-bit sync body and 6-bit sync ID. 30 While sync IDs of sync- data in a preamble of a BD-RE are respectively '000 100' and '010. 000' as shown in Fig. 2a, the preamble -of a BD-ROM structured in accordance with the present 11 invention includes .two sync data whose. IDs. are FSO('000 001') (Sync_3) and FS6('010 000') (Sync 2). -The sync data 'Sync_3' is placed ahead of the sync data. 'Sync2' . In addition, the post-amble 'PoA' in Run-out of a BD-ROM 5 structured in accordance with the present invention,. as shown in Fig. 3b, includes ~sync data whose ID is FS4 ('000 100') (Sync_1). This is different from a BD-RE in that sync data with sync ID of FSO(000 001') is written in the post-amble of a BD RE.: 10. In case of a BD-RE, if two RUBs are created a pair of Run-in .and Run-out is formed as illustrated in Fig.. 1c. This pair-of-Run-in and .Run-out .(that corresponds .to. a linking area) includes three syic data whose recording- order is 'Sync_1', 'Sync 2' and 'Sync._3'. By the way, the recording. order of the 15 BD;ROM is' 'Sync_2' and 'Sync l' which is reverse order of.a BD-RE.

Consequently,* although the BD-ROM structured in accordance with *the present invention is same in physical recording format with -a BD-RE it can be distinguished from a 20 BD-RE because of sync data written order in a linking area. In addition, whether or not -a current area is -linking. area of a BD-ROM is easily determined based on arrangement. of the synd data. In -the above embodiment, the Run-in, Run-out and the 25 guard 'Guard-3' may include information similar to the recorded on corresponding areas of a .BD-RE. .The structure . of a linking area of the BD-ROM can be differently defined as depicted in Fig. 4a that illustrates .the second embodiment of the present- invention. As shown Fig. 4a, 30 in case of a BD-ROM, two linking frames of same size (1932 channels .bits) constitute a single linking area while, in case of a ~BD-RE, 1104-bit Run--in and 2760-bit Run-out, which are 12 . different in size, constitute a single linking area. The two linking frames are in same structure and each frame is composed of 30-channel-bit~ frame sync, 9-byte physical address,- 114-byte user data, and 32-byte parity. 5 The 114-byte user data ..~may include a variety *of additional information, e.g., anti-piracy information that makes it impossible to illegally copy contents such as a movie recorded on 'a BD-ROM to other medium, or control information to be used for a servo-control operation. 10 -Fig. 4b illustrates the third embodiment of the present invention. The linking area in the third embodiment .is composed of two- same-sized (1932 channel bits) linking frames and each frame- is composed. of a 30-channel-bit frame :sync, 9-byte . physical address, 146-byte user data. Compared with 'Fig. 4a, 15 the embodiment of Fig. 4b is different in that it has rio parity. Useful information can be -written in the '146-byte user data space. The -useful information is anti-piracy information that makes it impossible to illegally copy contents such as a movie recorded on a BD-ROM tot other medium,- or* control 20 information to be used for a servo-control6peration.

Fig. 46 illustrates the -fourth embodiment of the. present invention. The linking. .area in the fourth .embdiment is composed .of two same-sized (1932 channel bits) linking frames and each frame is composed of a 30-channel-bit frame sync, and 25 155-byte user data. Compared with Fig. 4a, the embodiment of . Fig. *4c is different in that -it has no physical address and no parity. This embodiment is also different from that of Fig. 4b in that it has no physical address. Fig. 4d illustrates the fifth :embodiment of~ the- present 30 invention. The linking area in'the fifth embodiment is composed of 30-channel-bit leading frame.-sync, 3714-channel-bit linking part, two 30-channel-bit rear syncs, and. two repetition 13 patterns that are 40 and -20 channel bits long, respectively. The 3714-channel-bit linking part is composed of three linking frames,. and- 4-bit dummy data. A linking area can have any possible structure different 5. from the above described. Data is'- written in the form of ECC block in the physical cluster and .the aforementioned seven frame syncs FSO-FS6 are used in an ECC block in general. At least one linking frame of the two shown in Fig. :.4a 10 uses new. frame sync 'FS n' that -is different. in sync ID from the -seven frame. syncs.. The sync ID of this new frame sync 'FS n'.' is '100 101' (FS7), '.101 010' (FSO), '010 .101' (FS9), *or .'101 01.' (FS1O) as shown ~in Fig.' 5.. All of the four sync candidates satisfy a constraint that 15 transition shift, which is specified for. a BD-RE, is not shorter in bit pattern than 2 bits. In the recording -embodiment of -Fig. 4a, the. frame sync ' FSO is written in the first linking frame, and .the frame sync .'FS n' in the second. 20 By. the'- way, data.' recording onto. a BD-ROM must satisfy 'Prohibit RMTR (Run-Limited TRansition) ' constraint of 17PP (Parity Preserve) modulation code that is data recording standard defined for a BD-RE. . . The Prohibit RMTR constraint, which is to ensure stable 25 detection of RF signal, is that minimum run length 2T, namely, '01': or '10' must not be repeated continuously more than six times. Therefore, it is preferable to use a frame sync with small transition frequency, namely, '100. 101' (FS7) or '101 001';(FS10) among the new frame syncs. to make successive bit 30 -trains* satisfy the constraint. The usage- of. frame syncs is -eplhained- in detail with reference to Fig. 6. The first case -illustrated in Fig.. 6b is the first 14 embodiment of the present invention. In this embodiment,- two 1932-channel-bit recording frames are recorded in a. linking area and each recording frame is composed of a frame s'nc; a physical address, user data, and parity. At least one of the 5 two recording. frames- includes the newly-defined frame sync 'FS n-'. For' instance, the frame sync 'FSO' with its identifying pattern (ID) '000 001' is written as th'e first frame sync while the new frame sync '.FS 'n'' whose sync identifying pattern is 10 '010 101', '1-01~010', or '100 1.01' is written in the second. In the *event that the new frame sync 'FS n' whose sync identifying pattern is '.010 101', '101 010', or '100. 101-' is used, the 9-byte physical address. following the frame .sync 'FS n' has an unscrambled starting data '00' as illustrated. in Fig. 15 6a. This . is because' it is advantageous to' satisfy the RMTR constraint of. 17PP. modulation codes defined for data recording on'a BD-RE. For* example, if the' new frame sync FS7 with sync identifying pattern of '100 101'- is used and, at the same time, 20 the following user data bita are "01 11 01-11" whose modulated bits by.17PP modulation table given in 'Fig. 7d are "010. 101 010 101", . the final modulated bits including the sync identifying pattern constitute "100 101 010 101 '010 101" where 2T pattern, the pattern .of one zero between neighboring two ones, arises 25 continuously seven times. However, if user data includes '00' at its head the above user data example becomes "00 01 11 01 11" whose 17PP modulated. bit train is "010 100 101 010: 101". Therefore, the final bits with the sync identifying pattern -~constitute "100 30 101 010 100 101 010 101" where.three 2T patterns, a 3T and -four 2T patterns arise sequentially. The second case illustrated in Fig. 6b is- the 'second 15 embodiment of the present invention. In this -embodiment, two 1932rchannel-bit recording frames -are recorded in a linking area- and each recording frame is composed of a frame sync, a physical address, user data, -and parity. At least one of the 5 two recording frames includes .the frame sync FS10(.1101 001'), one of the newly-defined frame sync 'FS n'. For instance, the frame sync FSO* with its identifying pattern '000 001' is written as the first frame sync while the new frame -sync FS1O whose sync identifying pattern is- '101- 001' 10 is written in -the second. In the event that the new frame sync 'FS10' is used, the RMTR constraint of 17PP modulation codes defined 'for. data recording on a BD-RE is automatically satisfied. Consequently, the following physical address has not to be started with- '00'. 15 . For example, if. the new frame sync :'FS1O' with sync identifying pattern of '101 001' is used and, at the same. time, the following user data bits are "01 11 01 11" whose modulated bits by 17PP modulation table given in Fig. 7d are "010 101 010 101", the final modulated- bit train with the sync -identifying 20 pattern constitutes "101 001 010 101 010 101" where one 2T, one 3T and six 2T patterns arise. The -third case illustrated in Fig. 6b i's the. third embodiment of the present invention. In this embodiment, two 1932 channel-bit recording frames are recorded in a linking 25 area: and each recording. frame is composed of a frame sync, a physical address, user data, and parity. The both recording frames include the newly-defined- frame sync 'FS n'. For instance, the firsthand the second frame sync use one of the .new frame syncs FS7('010 101'), FS8('101 010'), and 30 FS9('100 101'.). In the event that. the new frame sync FS7, FSB or FS9 is used, a physical address of 9 bytes following the frame 'sync 16 FS7, FSB or FS9 has an unscrambled -starting data '00' as illustrated in .Fig. Ga. This is, as explained:- before, to satisfy better 'the RMTR constraint ~of 17PP modulation. codes defined for data recording on a BD-RE. 5 In case that the new frame sync FS7(*100 101') is used, the RMTR constraint can be satisfied by writing user data space following the frame sync-having data other than "01 11 01 11, The fourth case illustrated in Fig. 6b is the fourth embodiment of. the present invention. In' this embodiment, two 10 1932-channel-bit recording frames are recorded in .a linking area and' each recording 'frame is. composed .of a frame sync, .a physical address, user -data, and parity. The. both recording frames irclude'the new frame sync FS10('101 0.01'). In the event that the 'new frame sync 'FS10' is used 'for 15 both data frames, the. RMTR constraint of 17PP modulation codes defined for. data recording .on a BD-RE is - automatically satisfied.- Consequently, the physical address following each frame sync has not to be started with bits '00'. If the. newly-defined. frame sync 'FS n' is used as 20 explained above, whether a current area is ~within a'. linking area or not is determined very easily and accurately because the new frame sync is different from those used in a physical - cluster. For example, in case that frame sync -combination is used 25 to determine a current area, because a frame sync combination made from 'FS n' written' in a linking area and FS4, FS4, and FS2 written respectively in the 29th' .to the 31st recording frames (Recording Frames #28 td #30) within a'previous physical cluster-becomes FSn-FS4 or FSn-FS2 which is'obviously different 30 from a combination made from frame syncs written in a physical cluster, whether a current area is within a linking: area is determined accurately based on the frame sync combination.

*' 17 The above explained several cases are summarized as follows. If adequate constraint is imposed to data to be written just.' after a frame'. sync, any .of the :four frame syncs can be 5 used. For instance, in case that a- physical address is written behind a frame sync, if - the. physical address always has a header of bits '00' the frame syncs FS8 and FS9.- can be used: with- no trouble. 10 In even case that a physical address is not written, if a certain'byte,. e.g., '08h' (0000 1000).. is written without being scrambled just behind- a frame sync, a bit train "000 . 100 100 10011: modulated from '08h' by the 17PP modulation is placed* after a frame sync, so that. any of the four new frame .syncs 15 FS7-FS1O can be used irrespective of RMTR constraint. Frame syncs are used such. that one of the four new frame syncs FS7-FS10 is written in a linking frame of the .two- while one of the already-known frame syncs FSO-FS6 is :in the other link-ing frame. Needless to say, the new frame syncs only can be 20 used. in. both of linking frames as shown in the cases 3 and 4 of Fig.- 6. In case that at least one selected from the new frame sync 'FS n' is' used. in a linking frame, a disc pl-ayer, that consists of an optical pickup .11, a VDP system 12, and -a D/A 25 converter 13 as.depicted in Fig. 9, is able to know very fast, whether a currently-read frame is within a linking area or a. data section (physical cluster) while reproducing recorded data from a- BD-ROM.

In case of a BD-RE, 31- recording frames individually 30 include one of seven .different frame syncs. However, seven frame syncs are not enough. :to define 31 recording frames distinguishably, so that a frame sync in -the previous recording . - - 18 frame or frames is used to identify a current recording frame -along with a frame sync in the current frame. In other 'words, a recording frame N can be identified by successive syncs of its own frame sync. and the frame sync in 5 the previous recording frames N-1, N-2, and/or N-3. -That is, although . one or two previous syncs N-1 and/or N-2- are not detected, the last-detected sync. N-3 can be used to identify the recording frame N along with its sync. For instance, supposing that a current recording frame is 10 the seventh, namely, recording frame #6, its frame syne' is PSI as shown in Fig. id.

However, the. frame sync PSI is- also written in the frames #1,. #23, and #24, so that previously-detedted -frame sync is used to identify the current frame. The currently-detected 15 frame sync PSI and the previously-detected frame- sync or syncs FS4, PSI, and/or FS3, which are respectively in the frames #5, #4 and #3, enable the current frame . to be identified to the seventh. Because arrangement of frame syncs is used to identify a 20 data frame as explained above, frame sync sequence from a previous data frame to a recording frame within .a linking area using the newly-defined frame sync should -be considered. This is explained in detail with reference to Figs. 7a to 7c. - Figs. 7a to 7c show applicable frame sync sequences- in 25 accordance with the present invention. . Fig. 7a is for the first case shown in Figs. 6a :and 6b and Figs. 7b and 7c are respectively for a sync pair of FS7-FS7 and FS7-FS8 of the third case shown in Fig. 6b. In case that frame syncs of FSO and FS7 are used as given 30 in Fig. 7a, the frame syncs of frames -N, N-l,' and N:-3 before the. frame #0 with' frame sync PSO are FS7, FSO and FS2 sequentially. as the case (1) -shows. This frame .#0 is. 19 corresponding to the first address unit of an RUB. As the case (2) shows, three frames before the frame #0 at the second row: have; frame. syncs of FS2, FS4 and. FS4, sequentially. This frame #0 -is corresponding to the middle address unit of an RUB.. As 5 the case (3) shows, three frames' before the frame #1 have frame sync sequence of FSO, FS7/FS2 and FS4, so that this frame '#1 is corresponding to - the first. address unit or the middle unit of. an RUB. In- addition, the three frames before the frame #2 are FS1,: FSO and .FS7/FS2 sequentially in their frame syncs as the 10 case: (4) shows, so that this frame #2 is corresponding to the first or the middle -unit of an RUB. As depicted in the 'A'-marked case of Fig.- 7a, both of the frame #0 -corresponding to the Middle address unit of an RUB and ;the frame #31 (the first linking frame) proposed newly in 15 accordance with the present invention have same frame sync. sequence of previous frames.. Therefore, it would be difficult to detect start of a linking. area, and the adoption of the pair of FSO and FS7- would. not be an adequate solution. Next case that only FS7 is.used as given in' Fig. 7b is. 20 explained. As given- in-the..case (1) of Fig. 7b, the frame sync. sequence before the frame #0 is .FS7/FS2, FS7/FS4 and FS2/FS4 and. :the frame #0 is the first address unit or the -middle unit of an RUB. As the' case .(2). shows, the frame sync sequence before the frame #1 is FSO, FS7/FS2 and FS7/FS4 and the' frame 25 #1 is the first or the middle unit'of an RUB. In addition, as . the ;case (3) shows, the frame sync sequence before the frame #2 is ES1, FSO.and FS2 and the frame #2 is also the first or the middle .unit of an RUB. However, as depicted in the- 'B'-marked case of Fig.. 7b, 30 the -first linking frame (frame #31) and the second (frame #32)', which are newly proposed in accordance with the present invention, have- same frame sync. -sequence at frames N and N-3, 20 which might cause a problem -in defining a. linking area. However, because two linking frames have newly-defined frame sync FS7 in case of use of two FS7s, 'this case of FS7-FS7 would cause less severe problem in detecting a linking area. than the case of 5 FSO-FS7 of Fig. 7a. Fig. 7c shows the case. that FS7. and FS8 are used. As the case (1) shows, the frame sync sequence ahead of the frame #0 is FS8/FS2, FS7/FS4 and FS2/FS4 and the frame #0- is the: first or the middle address unit of an RUB. As the case (2) shows, 10 the frame sync sequence before the frame #1 is FSO, FS8/FS2 and FS7/FS4 and the frame #1 is the first or the middle unit of an RUB. In 'addition, as the case (3) shows, the frame sync sequence ahead of the frame #2 is FS1,--FSO and FS7/FS2 and the 15 frame #2 is also the first and the middle unit of an RUB. As shown.'in Fig. 7c, the use of FS7. and FS8 dose not reveal same previous frame sync sequence before any frame, namely, the previous frame sync. sequence before. any frame is unique,- therefore, it causes no problem -in detecting a linking 20 area contrary to the'two cases of Figs. 7a and 7b. Consequently, the use of FS7 and FS8 is the best for a linking -area. structured in accordance with the present invention. In addition, the. frame syncs FS7 and FS8 satisfy RMTR constraint as explained before. 25 Fig. 8 is a flow diagram of an embodiment of a method to reproduce a recording medium*.structured in accordance with the present invention. If a BD-ROM containing a linking area structured in accordance with the present invention is loaded (S81)-, 30 management information for reproducing control written in .the BD-ROM is read into a niemory first (S82). Because the management information has been written in a lead-in area in 21 general; it is read out at an initial preparing stage by an optical pickup. Afterwards, reproduction of main data is started under control 'of a controlling unit (S83).. During the reproduction it is checked whether a frame sync is detected 5 (S84). If detected, it is determined whether or not the detected sync is one of syncs written in main data area (S85). . This determination is possible if a disc. recording/reproducing device . having syncs .FSO-FS8 stored therein compares the detected sync with the stored ones. 10 If it -is determined that the 'detected sync is one- of syncs (FSO-FSG) written -in the. main data area (S86), reproduction continues. However, if it is determined that the detected sync dose not pertain to one of syncs (FSO-FS6), which. means that it is a newly-defined sync FS7 or FS8, a current 15 location is regarded a. linking -area (S87) and then whether - within the first linking frame .or within the second is re checked (SB8).. If within the first linking frame, data following.~its frame sync is descrambled out- (S89) . Otherwise, the current location is regarded the second linking frame and* 20 then data just'after its frame-sync is descrambled out (890).

Therefore, .a disc player, that consists of an optical pickup 11, a VDP system 12, and a D/A converter 13 as depicted' in -Pig. 9, can detect more accurately a physical address..and user data within the first and the second linking frame 25 (Recording Frames #k+l, .#k+2) of a BD-ROM when it -is placed - therein. Especially, if the * user data contains' useful information for~ anti-piracy or servo-cQntrol, the. disc play conducts an operation suitable .to the useful information. - As explained above, .whether a current location, which an 30 optical pickup. is on, is within a linking area or main data -area can be known easily and fast through detecting and comparing newly-defined frame sync. -22 (2) Physical. Address In the linking frame structure shown in Fig. 4a, there are three cases in writing a physical address in each recording 5 frame of a linking area as -shown in Fig. 10a. The first case writes in both linking frames an AUN of a physical cluster #k+l closest behind the frames, and the second case writes an AUN of a physical cluster #k closest before the frames. In the third case, an AUN of a physical cluster #k- closet 10 before the first- linking frame is written in the first while an AUN of a physical cluster #k+1 closest behind the second linking frame is written in the second. The physical address, composed of 4-byte address, 1-byte reserved and 4-byte parity as .shown iri. Fig. 11a, is encoded -to 15 have error recovery capability by RS(9,5,'5) that.'is used' for. a BD-RE. The processing to make an address have error recovery capability will be described in detail later. Therefore, a disc player, that consists of an optical pickup 11, .a VDP system 12, and a D/A converter 13 as -depicted 20 in-Fig. 9, can detect more accurately a physical address--and user data within the first and the second linking frame (Recording Frames #k+l, #k+2) of a BD-ROM when it' is placed -therein. Especially, if the user data . contains useful information for anti-piracy or- servo-control, the disc play 25 conducts an operation suitable to the useful information. In the linking frame . structure shown ' in Fig.. 4d, there are two cases in writing a physical address in each of three recording frames of .a linking area as shown in Fig. 10b. The first case writes in three linking frames an AUN of .a physical 30 cluster #k+1 closest' behind. the frames,* and- the- second case*' writes an AUN of' a physical cluster: #k closest. before 'the frames. 23 The physical address, composed of 4-byte address, 1-byte reserved and'.4-byte parity as. shown in Fig. 1la, is encoded to have. error recovery- capability by RS(9,5,5) that is used for a BD-RE. The processing to make *a physical address have error 5 recovery .capability will-be described in detail later. Therefore, a disc player, that consists of an optical pickiip 11, a VDP system 12, and a D/A convert.er-13 as depicted in* Fig. 9, can detect mo'e accurately a- physical address and user data within the successive three- linking frames (Recording 10 Frames .#k+1, #k+2, #k+3) of a.BD-ROM when it is placed therein. Especially, if the. user data contains. useful information for antilpiracy or servo-:control, the disc. play conducts an -operation-suitable to the useful information. Fig. 10c shows - another embodiment. of the present 15 invention that writes an address in a recording frame. Each of the linking .frames (Recording Frames #k+1, #k+2) contains a 9 byte :physical address 'where 4-byte actual address is included. The 4-byte actual address may have same value with 16 AUNs #0-#.5 written in a ..physical-. cluster before or behind the 20 linking frames. A 4-byte actual address written in a physical cluster bef6(e the first linking frame is composed.of a 27-bit address, a 4--bit sequence number (0'000-1111)~ indicative of* its order -in physical addresses and.1-bit fixed value '0', as shown in.Fig. 25 10c.: All. of .the 27-bit addresses written in the. leading physical cluster has same value. Another 4-byte actual address written in a physical cluster behind the second linking frame is composed.of a 27-bit address, a 4-bit sequence. number (0000-1111) :indicative of its 30 order in.physical.addresses and 1-bit fixed value '0', as shown in .Fig. 10c. All of the 27-bit. addresses written in the following physical cluster has same value.. 24 As aforementioned, the 4-byte actual address of the.first linking frame includes an address. written in the physical address. located .therebefore. For example, the 4-byte. -actual address of the first linking frame has the address value of the 5 closest 16-th AUN (AUN #15). of 27-bit and '11110', as shown in Fig. *10c. In - this case, -the last 1-bit '0'- 'of the five bits '11110' to be written in the first linking frame cari be replaced with '1' in order to indicate. that a physical address is one written in a linking area other than a physical cluster. 10 In addition, -'the 4-byte actual address of. the second linking frame includes an. address written in the physical address located thereafter. For example, the 4-byte actual address of the .second .linking frame has the address value of the closest first AUN (AUN #0) *of 27-bit and '00000', -as. shown 15 in Fig. 10c. sIn' this case, the last 1-bit '0' .of the five .bits '00000' to be written in -the second linking frame can be replaced with '1' -in order to indicate that a physical address is one written -in a linking area other than a physical cluster. The final five bits of the 4-byte actiail address .'to be 20 written in 'the first linking. frame may be '00000' while the final five bits to be written in the second linking frame may be '11110'. In addition, an address written in an arbitrary physical cluster among physical clusters located before or after a 25 linking area can be written in' the first and the second linking frame as explained before with reference to Fig. 10c. (3) Scrambling Fig. 1a is a -block~ diagram of a linking frame. 30 constructing circuitry for the structure shown in Fig. 4a. The linking frame constructing circuitry comprises a scrambler .10 and an adder 20. The scrambler 10 scrambles 114-byte user data 25 with: 9-byte physical address to- make its DSV~ (Digital Sum Value) close zero and adds the 9-byte physical .address before the scrambled user data. The adder 20 adds 32-byte parity behind the address-added 5 user data - from the scrambler 10 as well as a 20-channel-bit iframp sync ahead of the address-added user data. Consequently, a complete, recording frame including 114-byte user data scrambled with a 9-byte physical address is -constructed. In the scrambling of user data, information other than a:. 10 9-by:e physical address can be used. Fig. 11b is a block diagram of another linking frame constructing circuitry for the structure shown in Fig. 4d. This linking frame- constructing circuitry comprises a scrambler 10' and an adder 20'. The scrambler 10' scrambles 62-byte user data 15 such as anti-piracy information with a 9-byte physical address to make its DSV (Digital Sum Value) Close .. zero and adds the 9 byte.physical. address before the scrambled user data. The 'adder7 20'. adds- 32-byte parity behind the address addeo user data from the scrambler 10'. consequently, -a 20 complete .103-byte recording frame -including 62-byte user data. scrambled with a 9-byte physical address is constructed. In the scrambling of user. data, information other than a 9-byte' physical address can be used.. Instead of constructing a linking frame including a frame 25-synci 9-byte physical address, 114-byte user data, and 32-byte parity as shown 'in Fig. 4a, a linking frame may be -constructed to have a- frame sync, 9-byte- physical address including 1-byte reserved and 4-byte parity, and 14 6-byte user data as shown in Fig. 4b or 12a.. The 146-byte user data may-be scrambled and the 30 4-byte actual .physical address may be used as a scrambling key.. That is, a part of 32 bits (Add --Add 31) of the 4-byte physical address is used. as an- initial loading value of a-16 26 bit shift register 101 in the scrambling circuitry, as shown in Fig. 12b. After the initial loading value is loaded in parallel into the shift register 101, one scrambling byte is. outputted. every bit shift. 5 Because the user data is '146-byte in length in the embodiment of Fig. 9, the part of physical address is loaded in parallel. into the shift register 101 every 146 shifts. The partial address- to be loaded changes as a linking area does. After the parallel loading, . 146 scrambling bytes (SO-S145) are 10 created and OR-ed exclusively with successive 146 bytes (DO-D145) of user data by an exclusive-OR gate. 10.2, sequentially. The successive 146 -bytes scrambled as before are written in a.linking frame. Instead of a physical address, a part of- frame sync 15 pattern or some repetitions - of bits '10' can be used as a scrambling key to scramble user data. Moreover, instead of a. physical address to be written.in a linking frame, one address among 16 addresses included in- a physical cluster before. or behind- a current linking frame may be used. Especially,. one 20 address.closest to a current linking frame is used among'.the 16 addresses.-. A physical address to- be written in a linking frame may be scrambled along with user data. written therein. In another embodiment of the present invention, a 25 physical address may not be written in a linking frame as shown in Fig. 4c. In this case,. a physical address before or behind a linking frame is used as a scrambling key, namely, an initial loading value- to the shift register. Because user data is 155 bytes long in this embodiment, same or different physical. 30 address is loaded as an initial value -into the shift-register every 155 shifts. As sh6wn in 'Fig. 13, a' part of the 4-byte address (Add, 27 #0~#31) is loaded in parallel into.-a 16-bit shift register 101' of a scrambler that- is also applicable to a 'BD-RE recording and then 155 8-bit scrambling bytes (SO-S154) are outputted. sequentially during the process of bit-shifts. 5 The successive 155 scrambling bytes (SO-S154) .are -exclusive-ORed with successive 155 user bytes (DO-D154) by an exclusive-OR *gate 102'. As a result, ~ 155 scrambled user data. (D'0-D'154). are produced and.they are written in a recording frame in a' .linking area. 10 Instead of a physical address, a- part of frame sync pattern or some repetitions of -bits '10' can be used as a scrambling key to'scramble user- data. (4) Dummy Data 15 In case .that useful data for. anti-piracy or -servo-control is rot written in .the user data space although two .recording'' frames are formed in' a linking area of a BD-ROM 'to ensure reproducing compatibility with a BD-RE, the user data space -may be. filled with an arbitrary certain value, e.g., '00h' as shown 20 in. Fig. 14a. A series- of such a filling'value is called dummy data.. If same data was filled in entire user data spaces the manufacturing process of a BD-ROM could be simplified more..-By the way, if -adjacent tracks had .same bit patterns crosstalk 25 would arise. Thus, as another embodiment of dummy data, 'several values, e.g., '00h', '1Olh', -'10h', '11h', 'FFh',- 'AAh', etc. are written -in user data' spaces by 'turns as illustrated in Fig.

14b in order to reduce probability of crosstalk. In this embodiment of dummy data recording, dummy data of 30 different values are recorded in the recording frames of. each linking frame allocated in a BD-ROM, - which reduces 'the probability that same recording patterns are formed between .28 neighboring tracks. Consequently, the crosstalk probability is reduced remarkably. In case that two recording frames. are formed in a linking area of a BD-ROM to ensure reproducing compatibility with a BD 5 RE, as another embodiment according 'to the present invention, the user data space' may be filled with arbitrary* several different values, e.g., '00', -01', '11' -which appear alternately as shown. in Fig. 14c. In the dummy. data recording. embodiment - of Fig. 14c,- a 10 linking area' has same data in their user data spaces while neighboring linking areas have .different dummy data. In this- embodiment, the probability that'- same recording patterns are formed between neighboring tracks is very low, therefore, the crosstalk probability is reduced compared with 15 the. embodimentof Fig. 14a. The manufacturing process of a BD ROM of this embodiment is simpler ~than that of Fig. -14b. In addition, if one value, e.g., 'Ooh' fills entire user data spaces after .scrambled with a physical. address that changes every- linking area, crosstalk can be eliminated 20 remarkably 'too. In case that '00h' fills the' user data spaces after scrambled, .if a. non-scrambled '08h' is placed 'at the foremost front of each user data space, any of the aforementioned new frame syncs can be used irrespective of the RMTR constraint 25 specified in 17PP modulation as explained before. (5) Construction of ECC.Block If useful and important information 'is written in the user' data space, .it is channel-encoded. to ensure its 30 reliability. RS(62,30,33) and- RS(248,216.,33) encoding system are used as the channel encoding method. Those encoding -systems have been also specified to be used to encode user data to be 29 written in physical clusters of a. BD-ROM.

Fig. .15a .shows a recording example in. which data is. recorded in a linking area structured in Fig. 4d. For recording useful data as -illustrated in Fig. 15a, 30-byte useful data-is 5 encoded first by RS(62,30,33) system, which creates 32-byte parity. For. this operation input data is sequentially stored in. a memory to organize a 30x309 data block. When a 30x309 data block is organized, every column is. sequentially scanned (151). 10 A 32-byte parity is produced by RS(62,30,33) encoding system every. one. scan of the column and .it is appended -thereto. As a result, a 62-byte data series is constructed. Each 62 bytes including the 'parity may be scrambled. In case of scrambling, a part of a physical address may be used as 15 a scrambling key as. explained -before. Next,' a 9-byte physical address is added in front of .the 62. bytes made' from the above process.. The 9-byte physical address may 'be composed of an actual physical address and parity thereof. For instance, 'The 9-byte physical address may 20 be composed..of a 4-byte actual' address,.. 1-byte -reserved, and a 4-byte parity. And,. 145-byte' dummy data is added to the 71 bytes including the physical address and then 'encoded by RS(248,216,33) system, as a result, -32-byte parity is added. 25 Finally, the added 145 dummy bytes are then removed to produce a 103-byte data unit to be writteriin a linking area. The above-explained operations are repeatedly conducted to'next 30-byte useful data to produce successive 103-byte data units. After three units are made, 4 dummy bits are -added 30 behind the three units and total 2467 bits are then 17PP modulated. After 17PP-modulation, the 2467 bits are extended to .3714 channel bits. 'The first frame sync of 30. channel bits is 30 placed in front of the modulated 3714 bits, and the second 30 channel-bit- frame -sync, .a 40-channel-bit repeated bit .pattern, the third 30-channel-bit frame sync, and another 20-channel-bit repeated bit pattern. are sequentially appended to the modulated 5. bits. The thusly-made 3864 channel bits are .. written in a linking area. In case- that useful data is small not enough to fill a single linking area as above, :dummy data is added to* a segment. of: useful data. to constitute 30 bytes. For instance, in case 10 that 3-byte useful data- is to be written per linking area. one - byte of the three has to constitute a single data unit unavoidably. Therefore, as' shown in Fig. 15c, only one 309-byte row is filled in a 30x309 data block and other 29 rows are' all filled with dummy data. This means that 29-byte dummy data is 15 added to 1-byte useful data .at every column. Afterwards, RS(62,30;33') encoding system .is applied to each column of the dummy-added 30 bytes. to append 32-byte parity thereto. In order to restore -useful data written in -a linking area as before, a decoding process, namely, reverse sequence of the 20 above-explained writing process, is conducted. In case that two same frames constitute a single linking area as illustrated in Fig. .4b, the user .data space of a linking frame may be'filled with 114-byte useful data .and 32 byte parity as shown in Fig.. 4a. In the recording example of 25 Fig. 4a, a different method from the described in Fig. 4b or 4c. is. used in channel encoding. to. ensure data reliability. The different method is explained with reference to Fig. 16. . Useful data is collected up to 2048 bytes first (SI). 4 byte EDC (Error Detection Code) is appended to a useful data 30 block composed of the colledted.2048 bytes (S2). The 2052 bytes including EDC is divided into eighteen 114-byte data units (S3). The first data unit is scrambled - (S4) and 9-byt'e physical 31 address is added therebefore- (S5). The. 93-byte dummy data is added to the 123-byte data .unit including the physical address -and .is encoded by RS(248,216,33)' system, whereby 32-byte parity is appended to the data unit. The added 93 bytes are removed to 5 produce 155-byte frame data (SG) which is then 17PP-modulated. Finally, the aforementioned .30-channel-bit frame sync is added in front of the frame data to make a complete linking frame of- 1932 channel bits (S7). The above-explained. sequential processes (S4-S7) are 10 applied to the next divided 114-byte data unit to make another linking frame. 'Thusly-made two linking frames are written in a linking area, as a result, the structure illustrated in. Fig. 4a .is formed. When each 114-byte data unit is scrambled :in the above 15 processes, a physical address is used in scrambling as explained before. Same.or different physical address, which is written in an RUB located before or behind a. linking area, is used for .the first and the second linking frame of a linking area. In case of using different- address, the first linking 20 frame uses an.address written before a linking frame while the second uses another address behind the linking frame. The physical address to* be written in each linking frame may be composed of 4-byte actual address, 1-byte reserved, and 4-byte. parity as mentioned before. In this- case, the .4-byte 25 parity is produced. by applying RS(9,5,5) channel coding system to the 5-bytes. In addition, the 4-byte actual address is composed of 27 bit address -and 5-bit address identifier. that is used to distinguish -individual physical addresses in linking areas. 30 A pair of '00000/11110' or '00001/11111' may be used as address identifier. In case of using the former (or the latter),. '00000' (or '00001') is inserted in a physical address in one 32 linking frame while '11110' (or '11111') is inserted in the other linking frame. In the above explanation, it was. described that the new frame sync 'FS n', which is different from the syncs 'FSO-FS6' 5 for data frames written in physical clusters,- can be used for liking frames. In case of using the new frame sync different from syncs of data frames, data 'to be written in physical clusters is encrypted with frame sync in .a linking .frame in order that. digital contents recorded on a BD-ROM can be 10 protected .against illegal copy. Although contents with such encrypted data recorded on a BD-ROM are copied onto a rewrit'able' disc, e.g., a BD-RE, the new frame sync 'FS n' in a linking frame is not copied onto a BD-RE and it is not created either during a BD-RE recording as 15 well. That is, a key having been used in encryption :Is not obtainable during reproduction of copied contents on a BD-RE, so that it is impossible to decrypt. consequently, contents on a BD-ROM can be.protected against illegal copy. The above-explained structure of a linking area of a 20 high-density read-only .recording medium according- to the present invention ensures -reproduction compatibility with a rewritable recording medium such as a. BD-RE when being reproduced by a disc player -or a disc .drive. In addition, the present structure of a linking area makes it possible for a 25 disc player or .a disc drive to conduct adequate operations by telling a read-only recording medium from a rewritable one very fast, if needed. Moreover, useful information can be reliably stored in a linking area through the above-explained recording .manners. 30 Although certain specific embodiments of. .the -present invention have been -disclosed, it is noted that the present invention may be embodied in other forms without departing 33 from the spirit or .essential characteristics thereof. The present embodimierts are therefore to be considered in all . respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, and all 5 changes that .come within the meaning and range of equivalency of; the claims are-therefore intended to be embraced therein. ~34

Claims (30)

1. A recording medium, comprising: a data area including at least two data sections and at least one sync signal; and a linking area to link neighboring data sections, the linking area including at least two 5 frame sync signals, where values of the at least two frame sync signals maintain uniqueness, wherein a frame in one of the data area and the linking area is identifiable based on a combination of a frame sync signal of the frame and a frame sync signal of a preceding frame, wherein the recording medium is a read-only recording medium and wherein a writing order of the two frame sync signals is different from a writing order of sync signals included in a 10 corresponding linking area of a writable recording medium.

2. The recording medium of claim 1, wherein the linking area includes at least two linking frames, a first linking frame and a second linking frame, wherein at least one frame sync signal is included in each linking frame.

3. The recording medium of claim 2, wherein each linking frame includes at least one 15 frame sync signal at a front of the linking frame.

4. The recording medium of claim 1, wherein each frame sync signal includes a frame sync ID.

5. The recording medium of claim 1, wherein the at least two frame sync signals in the linking frames are different from a plurality of sync signals in the data area. 20

6. The recording medium of claim 4, wherein each frame sync ID is one of '100 101', '101 010', '010 101' or '101 001'.

7. The recording medium of claim 6, wherein a frame sync signal written in a first linking frame is '100 101' and a frame sync signal written in a second linking frame is '101 010'.

8. The recording medium of claim 7, wherein a value of '08h' follows the frame sync signal of each linking frame.

9. The recording medium of claim 8, wherein a value of 'OOh' follows the value of '08h' for a remainder of the linking frame. 5

10. The recording medium of claim 1, wherein a signal distance between the at least two frame sync signals maintains uniqueness.

11. The recording medium of claim 10, wherein the signal distance between the at least two frame sync signals is at least two.

12. The recording medium of claim 1, wherein the at least two frame sync signals maintain 10 uniqueness over n frames, where n>2.

13. A method of forming a recording medium, comprising: forming a linking area to link neighboring data sections of a data area while recording data onto the recording medium, the linking area including at least two linking frames; selecting values of at least two frame sync signals, to maintain uniqueness; and 15 writing the at least two frame sync signals in the linking area to link the neighboring data sections, wherein the data area includes at least one sync signal which is different from the at least two frame sync signals included in the linking area, and a frame in one of the data area and the linking area is identifiable based on a combination of a frame sync signal of the frame and a 20 frame sync signal of a preceding frame, wherein the recording medium is a read-only recording medium and wherein a writing order of the two frame sync signals is different from a writing order of sync signals included in a corresponding linking area of a writable recording medium.

14. A method of reproducing data from a recording medium, comprising: utilizing a linking area, including at least two frame sync signals, which maintain uniqueness and link neighboring data sections of a data area, to reproduce the data, wherein the data area includes at least one sync signal which is different from the at least two frame sync signals included in the linking area, and a frame in one of the data area and 5 the linking area is identifiable based on a combination of a frame sync signal of the frame and a frame sync signal of a preceding frame, wherein the recording medium is a read-only recording medium and wherein a writing order of the two frame sync signals is different from a writing order of sync signals included in a corresponding linking area of a writable recording medium. 10

15. The method of claim 14, further comprises, determining whether or not a current position is a linking area based on at least one of the at least one frame sync signal.

16. The method of claim 14, further comprises, determining whether a current position is a front or rear of a data section based on the at 15 least one of the at least one frame sync signal.

17. The method of claim 14, wherein a data section has a plurality of frame sync signals, and at least two frame sync signals of the linking area are different from the plurality of frame sync signals of the data section.

18. The method of claim 17, wherein one of the at least two frame sync signals is a frame 20 sync signal of bit pattern "100 101", and another is a frame sync signal of bit pattern "101 010".

19. A method of recording data on a recording medium, comprising: utilizing a linking area, including at least two frame sync signals, wherein the at least two frame sync signals maintain uniqueness and are different from a sync signal included in a data area, to record the data, wherein a frame in one of the data area and the linking area is identifiable based on a combination of a frame sync signal of the frame and a frame sync signal of a preceding frame, wherein the computer-readable medium is a read-only recording medium and wherein a writing order of the two frame sync signals is different from a writing order of sync signals 5 included in a corresponding linking area of a writable recording medium.

20. The method of claim 19, wherein a data section of the data area has at least seven different frame sync signals, and the at least two frame sync signals of the linking area are different from the seven different sync signals of the data section.

21. The method of claim 20, wherein one of the at least two frame sync signals is a frame 10 sync signal of bit pattern "100 101", and another is a frame sync signal of bit pattern "101 010".

22. The method of claim 21, wherein a first of the at least two frame sync signals and a second frame sync of the at least two frame sync signals are recorded in order between two data sections.

23. An apparatus for reproducing a recording medium, comprising: 15 an optical pickup configured to read data of a linking area, which links neighboring data sections of a data area and includes at least two frame sync signals, wherein values of the at least two frame sync signals maintain uniqueness; and a control unit configured to determine whether a currently read position is within the linking area based on a combination of a frame sync signal of a frame and a frame sync signal of 20 a preceding frame read by the optical pickup, and to control a reproduction according to a result of the determination, wherein the recording medium is a read-only recording medium and wherein a writing order of the two frame sync signals is different from a writing order of sync signals included in a corresponding linking area of a writable recording medium. 25

24. The computer-readable medium of claim 1, wherein the at least two frame sync signals to be used in the linking area are different from a plurality of sync signals of the data area.

25. The method of claim 13, wherein the writing step writes at least one frame sync signal in each linking frame of the linking area.

26. The method of claim 25, wherein the at least one frame sync signal is written at a front of each linking frame of the linking area. 5

27. The method of claim 13, wherein each of the at least two frame sync signals includes a frame sync number and a frame sync ID.

28. The method of claim 13, wherein the selected values of each of the at least two frame sync signals are different from values of frame sync signals of the data area.

29. The method of claim 13, wherein the selected values of the at least two frame sync 10 signals are different from each other.

30. The apparatus of claim 23, wherein controlling unit is configured to control the reproduction such that data within the neighbouring data sections of the data area is reproduced continuously if it is determined that a currently read position is not the linking area, and data within the linking area is not reproduced if it is determined that the currently read position is the 15 linking area.