Patent Publication Number: US-7911905-B2

Title: Write-once optical disc, and method and apparatus for recording/reproducing management information on/from optical disc

Description:
This application is a continuation of U.S. application Ser. No. 11/984,034, filed on Nov. 13, 2007 now U.S. Pat. No. 7,570,559; which claims priority to U.S. application Ser. No. 10/911,728, filed on Aug. 5, 2004 now U.S. Pat. No. 7,317,670 under 35 U.S.C. §119; which claims the priority of Patent Application No. 2003-054165 filed in Republic of Korea on Aug. 5, 2003; Patent Application No. 2003-073088 filed in Republic of Korea on Oct. 20, 2003; and Patent Application No. 2004-007608 filed in Republic of Korea on Feb. 5, 2004. The entire contents of each of these applications are hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a write-once optical disc and an apparatus and method for recording/reproducing management information on/from the optical disc. 
     2. Discussion of the Related Art 
     As an optical recording medium, optical discs on which high-capacity data can be recorded are widely being used. Among them, a new high-density optical recording medium (HD-DVD), for example, a Blu-ray disc, has been recently developed for recording and storing high-definition video data and high-quality audio data for a long-term period. 
     The Blu-ray disc involves the next generation HD-DVD technology and is the next generation optical recording solution, which has an excellent capability to store data more than existing DVDs. Recently, a technical specification of an international standard for HD-DVD has been established. Various standards for Blu-ray discs are being prepared. Particularly the standards for a write-once Blu-ray disc (BD-WO) are being proposed. 
       FIG. 1  schematically illustrates the structure of a recording area of a rewritable Blu-ray disc (BD-RE) according to a related art. As shown in  FIG. 1 , the disc is divided into a lead-in area, a data area and a lead-out area, starting from an inner radius thereof. Further, the data area is provided with an inner spare area (ISA) and an outer spare area (OSA) respectively disposed at the inner and outer radiuses to replace defective areas, and a user data area provided between the spare areas to record user data therein. 
     If a defective area is generated in the user data area while data is recorded on the rewritable Blu-ray disc (BD-RE), data is transferred from the defective area to the spare area to replace and record data in the spare area. This portion of the spare area is known as a replacement area for replacing the defective area. Additionally, position information related to the defective area, that is, position information on the defective area and on the corresponding replacement area is recorded in defect management areas (DMA 1 , DMA 2 , DMA 3 , and DMA 4 ), which are provided in the lead-in/out areas, to perform defect management. The BD-RE has a cluster as a minimal recording-unit. One cluster has a total of 32 sectors, and one sector has 2048 bytes. 
     Since rewriting can be performed in any area of the BD-RE, the entire area of the disc can be randomly used irrespective of a specific recording manner. Also, since the defect management information can be written, erased and rewritten in the defect management areas (DMAs), it does not matter that the size of the defect management area is small. In particular, the BD-RE allocates and uses 32 clusters for each of the defect management areas (DMAs). 
     On the other hand, in a write-once disc such as a BD-WO, writing can be only made once in a specific area of the disc and thus, the manner of recording is much limited. As such, defect management becomes one of the important matters when data is to be recorded on a high-density write-once disc such as a BD-WO. Accordingly, the write-once disc requires a management area to record therein information on defect management and on disc management. In this regard, the write-once optical disc requires a larger management area for recording information on the defect management and on the disc use state due to its unique ‘write-once’ characteristic. 
     However, a unified standard satisfying the above requirements is not available for a write-once disc such as a BD-WO. Further, any standard related to presently declared write-once optical discs cannot solve the above drawbacks. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is directed to a write-once optical disc, and an apparatus and method for recording/playing-back management information on/from the optical disc that substantially obviate one or more problems due to limitations and disadvantages of the related art. 
     An object of the present invention is to provide a method for recording disc management information on a write-once optical disc, a disc initializing method and a disc initial reproducing method. 
     Another object of the present invention is to provide a method for separately recording and managing management information, thereby enhancing the use efficiency of a plurality of temporary defect/disc management areas (TDMAs) provided on a write-once optical disc. 
     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 objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided a recording medium having at least one recording layer, the recording medium comprising: a data area to record user data; a lead-in area and a lead-out area; and a plurality of temporary defect management areas (TDMAs), wherein at least one of the TDMAs includes an indicator identifying a usage status of the TDMAs. 
     In another aspect of the present invention, there is provided a write-once recording medium comprising: at least one recording layer; a lead-in area, a data area, and a lead-out area on the at least one recording layer; a separate indicator area in the lead-in area; and an indicator stored in the separate indicator area and identifying which one of temporary management areas on the write-once recording medium has an in-use status. 
     In a further another aspect of the present invention, there is provided a method of recording management information on a recording medium, the recording medium including a plurality of temporary defect management areas (TDMAs) on at least one recording layer, the method comprising: recording an indicator in at least one of the TDMAs, the indicator indicating which TDMA is in use. 
     In a still another aspect of the present invention, there is provided a method of recording management information on a write-once recording medium, the write-once recording medium including a lead-in area, a data area, and a lead-out area on at least one recording layer, the method comprising: allocating a separate indicator area in the lead-in area of the write-once recording medium; and recording an indicator in the separate indicator area, the indicator identifying which one of temporary management areas on the write-once recording medium has an in-use status. 
     In a still another aspect of the present invention, there is provide an apparatus for providing management information on a recording medium, the recording medium including a plurality of temporary defect management areas (TDMAs) on at least one recording layer, the apparatus comprising: a recording/reproducing part to record an indicator in at least one of the TDMAs, the indicator indicating which TDMA is an in-use TDMA. 
     In a still another aspect of the present invention, there is provided an apparatus for providing management information on a write-once recording medium, the write-once recording medium including a lead-in area, a data area, and a lead-out area on at least one recording layer, the apparatus comprising: a recording/reproducing part to allocate a separate indicator area in the lead-in area of the write-once recording medium, and to record an indicator in the separate indicator area, the indicator identifying which one of temporary management areas on the write-once recording medium has an in-use status. 
     It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE 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 embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings: 
         FIG. 1  is a schematic view illustrating the structure of a BD-RE according to a related art; 
         FIGS. 2A and 2B  are views respectively illustrating a structure of a single-layer write-once optical disc and a structure of a dual-layer write-once optical disc according to an embodiment of the present invention; 
         FIG. 3  is a view illustrating an example of information recorded in a temporary disc/defect management area (TDMA) of a write-once optical disc according to an embodiment of the present invention; 
         FIG. 4A  is a view illustrating an example of a TDMA location indicator (TLI) of a single-layer write-once optical disc according to a first embodiment of the present invention; 
         FIGS. 4B-4E  are views illustrating examples of a TDMA location indicator (TLI) of a dual-layer write-once optical disc according to the first embodiment of the present invention; 
         FIG. 5A  is a view illustrating an example of a TLI of a single-layer write-once optical disc according to a second embodiment of the present invention; 
         FIGS. 5B and 5C  are views illustrating an example of a TLI of a dual-layer write-once optical disc according to the second embodiment of the present invention; 
         FIG. 6A  is a view illustrating an example of a TLI of a single-layer write-once optical disc according to a third embodiment of the present invention; 
         FIGS. 6B and 6C  are views illustrating an example of a TLI of a dual-layer write-once optical disc according to the third embodiment of the present invention; 
         FIGS. 7 ,  8  and  9  are views illustrating examples of different locations of a TLI on a single-layer write-once optical disc and on a dual-layer write-once optical disc according to an embodiment of the present invention; 
         FIGS. 10A and 10B  are views illustrating information recorded in a TLI according to an embodiment of the present invention; 
         FIGS. 11A and 11B  are views illustrating the structure of a single-layer write-once optical disc having an expanded spare area and a TLI area according to an embodiment of the present invention; 
         FIGS. 12A ,  12 B,  13 A and  13 B are views illustrating the structure of a dual-layer write-once optical disc having an expanded spare area and a TLI area according to an embodiment of the present invention; 
         FIG. 14  is a view illustrating an initializing method according to a spare area allocation mode of the present invention; and 
         FIG. 15  is a view illustrating a reproducing/recording apparatus for a write-once optical disc according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     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, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
     For description convenience, a write-once optical disc is exemplified as a write-once Blu-ray disc (BD-WO). 
       FIGS. 2A to 3  are views illustrating a structure of a write-once optical disc and a method for recording management information on the disc according to an embodiment of the present invention. 
     Particularly,  FIG. 2A  illustrates a single-layer write-once optical disc (e.g., a single-layer BD-WO) having one recording layer according to an embodiment of the present invention. As shown in  FIG. 2A , the single-layer optical disc includes a lead-in area  30 , a data area  40  and a lead-out area  50  in the inner to outer radius direction. The data area  40  includes inner and outer spare areas (ISA 0 ) and (OSA 0 ), and a user data area  42 . The lead-in area  30  and the outer spare area OSA 0  respectively include temporary disc/defect management areas (TDMA 0 ) and (TDMA 1 ). 
     In addition, a plurality of disc/defect management areas (DMA 1 ˜DMA 4 ) are provided in the lead-in and lead-out areas  30  and  40 . While the TDMAs store defect/disc management information temporarily, the DMAs store the defect/disc management information more permanently. For instance, when the disc is to be finalized, the management information stored in a TDMA is transferred to and stored in each of the DMAs. 
       FIG. 2B  illustrates a dual-layer write-once optical disc (e.g., a dual-layer BD-WO) having two recording layers according to an embodiment of the present invention. As shown in  FIG. 2B , the dual-layer optical disc includes a first recoding layer (Layer  0 ) and a second recording layer (Layer  1 ). Each of the recording layers includes management areas (Inner Areas) and (Outer Areas) in the inner and outer radius areas of the disc. The DMAs  1 - 4  are provided in each of the recording layers. 
     The dual-layer disc further includes a data area  45  in each of the recording layers, each data area having a user data area  47  for storing therein user data. Inner and outer spare areas ISAO and OSAO are provided in the data area  45  of the first recording layer (Layer  0 ). Inner and outer spare areas ISA 1  and OSA 1  are provided in the data area  45  of the second recording layer (Layer  1 ). The size of the ISAO is fixed whereas the size of each of the OSA 0 , OSA 1  and ISA 1  is variable. For instance, the size of the ISA 1  may be (L*256) clusters, and the size of the OSA 0  and OSA 1  may be (N*256) clusters, where N and L are positive integers. 
     As shown in  FIG. 2B , the TDMAs on the dual-layer write-once disc include TDMA 0  and TDMA 1  each having a fixed size (for example, 2048 clusters) in the Inner Area, and TDMA 2 , TDMA 3  and TDMA 4  that are provided respectively in the spare areas OSA 0 , OSA 1  and ISA 1  having a variable size. The sizes of the variable TDMAs vary according to the sizes of the corresponding spare areas. 
     For the dual-layer disc, the TDMA 0  and TDMA 1  should be necessarily provided on the disc, whereas the TDMA 2 , TDMA 3  and TDMA 4  may be selectively allocated with their various sizes being, e.g., a ¼ size of the corresponding spare area. That is, the TDMA 2  and TDMA 3  may have appropriate sizes of P=N*256/4 clusters, and the TDMA  4  may have an appropriate size of Q=L*256/4 clusters, where N and L are positive integers. For the single-layer disc, the TDMA 0  should be necessarily provided don the disc, while the TDMA 1  may be selectively provided. 
     In accordance with an embodiment of the present invention, a single-layer write-once optical disc (e.g., a single-layer BD-WO) can have the maximum of 2 TDMAs. A dual-layer write-once optical disc (e.g., a dual-layer BD-WO) may have the maximum of 5 TDMAs. 
     Hereinafter, the structure and characteristics of the optical disc shown in  FIGS. 2A and 2B  are discussed. For description convenience, the dual-layer write-once optical disc is exemplified. 
     First, the write-once optical disc should include a plurality of areas for recording a variety of management information of the disc therein due to its write-once property. As such, the optical disc according to the present invention includes a plurality of TDMAs in addition to a plurality of DMAs. 
     According to the present invention, the plurality of TDMAs are used in a specific use sequence/order. For example, the TDMAs can be used in the sequence of the TDMA 0  to TDMA 4  in the dual-layer disc, or in the sequence of the TDMA 0  and then the TDMA 1  in the single-layer disc. For instance, in the case of the dual-layer disc, as user data recording is performed on the disc, appropriate information (e.g., TDDS, TDFL, etc. as shown in  FIG. 3  to be discussed later) is recorded into the empty TDMA 0  first. When the TDMA 0  is full (i.e., fully used up) with such information recorded therein, then the empty TDMA 1  is next used to record therein appropriate information associated with the user data recording. Once the TDMA 1  is fully used up, then the TDMA 2  is next used and so on. It is noted that the TDMAs can be used according to any designated sequence as desired. Identification numbers (TDMA 0  to TDMA 4 ) are given to the TDMAs in a serial sequence depending on a use sequence. 
     Furthermore, the write-once optical disc according to the present invention includes a separate area in which management information for managing the plurality of TDMAs is recorded. Such management information is referred to herein as a TDMA location indicator (TLI). The TLI can also be referred to as a TAI (TDMA access indicator). The TLI indicates which TDMA, among all the TDMAs that are to be used according to a designated sequence, is an “in-use TDMA”. An “in-use TDMA” is a TDMA that is currently being used/accessed or that is currently available for use, among all the TDMAs having the designated use sequence. According to the various embodiments, the in-use TDMA indication by the TLI can be implemented using a TDMA in-use indicator or a TDMA full indicator, which will be discussed later in more detail. 
     The TLI allows an initial disc access time to be reduced greatly since the TLI identifies the in-use TDMA and thus, information on the last defect management and on the disc use state can be quickly obtained from the identified in-use TDMA. This is beneficial especially when the disc is initially loaded. Without the TLI, all the TDMAs have to be scanned to determine which TDMA is the in-use TDMA in order to obtain the necessary management information from that in-use TDMA. 
     The TLI according to the present invention can be provided in various areas of the disc. Specifically, the TLI can be provided anywhere in the management areas (the lead-in area, the lead-out area and the like) of the disc, which are accessible by an optical recording/reproducing apparatus to obtain a variety of disc information prior to the actual reproduction. In the single-layer disc of  FIG. 2A , for instance, a TLI can be provided in the lead-in area  30 . In the dual-layer disc of  FIG. 2B , a TLI can be provided in the lead-in area at the first recording layer (Layer  0 ). Other examples of locations at which the TLI can be allocated will be discussed later. 
       FIG. 3  illustrates a variety of information on the disc defect management and on the disc use state, where this information is recorded in the TDMA(s). Whenever recording is performed on the disc, the recording is generally performed by more than one cluster, a cluster being generally a minimal recording-unit. Various disc management information recorded in the TDMA (e.g., TDM 0 , TDMA 1 , TDMA 2 , TDMA 3 , or TDMA 4 ) is collectively referred to herein as TDMS (temporary disc management structure) information. The TDMS information can be changed or added depending on a standard. 
     As shown in  FIG. 3 , the TDMS information includes, but is not limited to, a Temporary Defect List (TDFL) for recording disc defect management information, a Sequential Recording Range Information (SRRI) applied in a sequential recording mode as information for representing the disc use state, a Space-Bit Map (SBM) applied in a random recording mode, and a Temporary Disc Definition Structure (TDDS) information including recent location information of the TDFL and the SRRI (or SBM). The SRRI and the SBM may not be concurrently used, and either the SRRI or SBM is recorded on the disc depending on the recording mode. 
     As an example, in the context of the disc structure shown in  FIGS. 2A and 2B , each of the TDMA 0 ˜TDMA 4  includes one or more TDFLs/SBMs/SRRIs each recorded with a TDDS in one cluster at each recording/updating time, as shown in  FIG. 3 . That is, each recording of a TDFL/SBM/SRRI with a TDDS is allotted one cluster. Generally, the last sector of each such cluster is designated to store therein the TDDS information as shown in  FIG. 3 . However, the first sector, instead of the last sector, of each such cluster can also be used to store the TDDS information. 
     The TDDS information includes general disc record/playback information, and is generally always checked at the time of loading the disc in the record/playback apparatus since it includes pointer information for indicating the recent locations of the TDFL and the SRRI (or SBM) as described above. According to the disc use state, the TDDS information is continuously updated and the updated TDDS information is written in the TDMA at each update/recording time. Thus, the last TDDS (e.g., the last TDDS  51  in  FIG. 3 ) in the latest TDMA used should be checked to access a variety of management information on a current disc use state. 
     As described above, the TDMAs for recording the TDMS information therein are used in a specific use sequence. For example, if the TDMA 0  is all used up in updating the TDMS information according to a need, the next TDMA according to the use sequence, e.g., the TDMA 1 , is then used to store therein the updated TDMS information. The present invention provides a TLI (TDMA management information) which identifies which TDMA among all the TDMAs having the specific use sequence is the in-use TDMA, and this method according to various embodiments will be now described referring to  FIGS. 4A-6C . The TLI structures and use of  FIGS. 4A-6C  are applicable to the TLIs and the disc structures shown in  FIGS. 2A and 2B  and subsequent  FIGS. 7-11A  and  12 A, or to any other disc structure that needs a TLI. 
       FIGS. 4A to 4E  illustrate the structure of a TLI according to a first embodiment of the present invention. This embodiment provides a TLI having one or more TDMA in-use indicators. More specifically,  FIG. 4A  illustrates the structure of a TLI in a single-layer write-once optical disc having one recording layer, and  FIGS. 4B to 4E  illustrate the structure of a TLI in a dual-layer write-once optical disc having two recording layers. Referring to  FIG. 4A , assume that the single-layer write-once optical disc has two TDMAs (TDMA 0 ) and (TDMA 1 ), e.g., as shown in  FIG. 2A  and the TDMA 0  and TDMA 1  are used in that sequence. Then the TLI  52  includes a TDMA 1  in-use indicator  53  having a size of a single recording-unit such as a single cluster  52   a . The TLI  52  manages the two TDMAs with the one cluster  52   a . The TDMA 1  in-use indicator  53  indicates directly whether or not the corresponding TDMA 1  is the in-use TDMA. This indication is implemented by providing certain recording in the one cluster  52   a  of the TLI  52 . If the TLI cluster  52   a  has this certain recording therein, then the TLI cluster  52   a  is said to be in the ‘recorded state’. If the TLI cluster  52   a  does not have this certain recording therein, then the TLI cluster  52   a  is not in the recorded state. If the TLI cluster  52   a  (the TDMA 1  in-use indicator  53 ) is not in the recorded state, it means that the firstly used TDMA 0  is the in-use-TDMA. If the TLI cluster  52   a  is in the recorded state, it means that the second used TDMA 1  is the in-use-TDMA, which means the firstly used TDMA 0  is full, i.e., fully used up, so that there is no recording space in the TDMA 0 . 
     In other words, if the firstly used TDMA 0  becomes full, e.g., during the user data recording operation of the disc, then the TDMA 1  according to the designated use sequence will be used to record data as the user data recording operation continues. At this point, designated certain data will be recorded into the TLI cluster  52   a  to place the TLI cluster  52   a  in the recorded state. The recorded state of the TLI cluster  52   a  indicates that the TDMA 1 , not the TDMA 0 , is now the in-use TDMA, i.e., currently available for use during the user data recording operation. Accordingly, by examining the recorded/unrecorded state of the TLI cluster(s), a recording/reproducing apparatus can identify quickly which TDMA can and should be currently used during a data recording operation of the disc. This reduces the disc access time greatly and provides an efficient and effective way to carry data recording operations of the disc. 
     According to the embodiments of the present invention, if the single-layer write-once disc has more than two TDMAs, then the total number of TLI clusters present in the TLI changes according to the total number of TDMAs present on the disc. For instance, if there is an X number of TDMAs on the disc, then there is an (X−1) number of TLI clusters in the TLI. Each of the TLI clusters corresponds to one of the TDMAs, generally excluding the first TDMA in the order of the TDMA use sequence. 
     According to the embodiments of the present invention, the recording of designated certain data into the TLI cluster(s) to place the TLI cluster(s) in the recorded state can be realized in many ways. For instance, a high frequency signal can be recorded in the TLI cluster(s) which would make it easier to check whether or not the TLI cluster(s) are in the recorded state. In other examples, dummy data or certain real data (not dummy data) can be recorded in the TLI clusters. An example of recording the real data in the TLI cluster(s) will be described later reference to  FIGS. 10A and 10B . 
     The use and structure of the TLI for a dual-layer write-once optical disc according to the first embodiment of the present invention is as follows. Referring to  FIG. 4B , the dual-layer write-once optical disc may have up to five TDMAs (TDMA 0  to TDMA 4 ) and thus, four clusters  55   a - 55   d  are allocated as a TLI  55 , one TLI cluster corresponding to one of the TDMA 1 -TDMA 4 . In this example, the TDMAs are used sequentially from the TDMA 0  to TDMA 4 . The first through fourth TLI clusters  55   a - 55   d  of the TLI correspond respectively to the TDMA 1 -TDMA 4 , and respectively represent TDMA 1  to TDMA 4  in-use indicators  56 - 59 . Thus, these clusters  55   a - 55   d  are thus sequentially recorded in the increasing address (e.g., PSN) direction. This is indicated by the arrow (“recording direction”) in  FIG. 4B . That is, if a particular TLI cluster is in the recorded state, this implies automatically that any of its previous TLI clusters are already in the recorded state. For instance, if the second TLI cluster is in the recorded state, this means the first TLI cluster is already in the recorded state. 
     Accordingly, if all 4 clusters  55   a - 55   d  of the TLI are not in the recorded state, it means that the firstly used TDMA 0  is the in-use-TDMA. If only the first TLI cluster  55   a  (TDMA 1  in-use indicator  56 ) is in the recorded state, it means that the TDMA 0  is full and the TDMA 1  is the in-use TDMA. If the first and second TLI cluster  55   b  (TDMA 2  in-use indicator  57 ) is in the recorded state, it means that the TDMA 0  and TDMA 1  are full and the TDMA 2  is the in-use-TDMA. If the third TLI cluster  55   c  (TDMA 3  in-use indicator  58 ) is in the recorded state, it means that the TDMA 0 -TDMA 2  are full and the TDMA 3  is the in-use-TDMA. If the fourth TLI cluster  55   d  (TDMA 4  in-use indicator  59 ) is in the recorded state, it means that the TDMA 0 -TDMA 3  are full and the TDMA 4  is the in-use-TDMA. 
     As an example, as shown in  FIG. 4C , if the first and second TLI clusters  55   a  and  55   b  are in the recorded state, it means that the TDMA 0  and TDMA 1  are full and the in-use-TDMA is the TDMA 2 . 
     Accordingly, by checking the TLI and determining the TLI cluster(s) after the disc is loaded, the recording/reproducing apparatus can identify the location of the currently in-use TDMA (i.e., it can determine which TDMA is the in-use TDMA). Thus, the recording/reproducing apparatus can quickly move to a start location of the in-use TDMA to read the lastly recorded TDMS information, thereby initially obtaining a variety of initialization information for reproduction. If there is no TLI as in the related art, the recording/reproducing apparatus must scan all of the TDMAs beginning from the TDMA 0  to determine which TDMA is currently available for use. And this creates a drawback that a long time is needed for initial reproduction. 
       FIG. 4D  illustrates a TLI structure of the dual-layer write-once disc in which the recording direction of the TLI clusters is reversed compared to the recording direction of the TLI clusters shown in  FIG. 4B . Referring to  FIG. 4D , in this example, the recording of the TLI  55  is sequentially performed from a cluster having a high Physical Sector Number (PSN) to a low PSN, i.e., from the fourth to the first TLI clusters  55   d - 55   a . The first through fourth TLI clusters  55   a - 55   d  now correspond to the TDMA 4  through TDMA 1 , respectively, and function as the TDMA 4 -TDMA 1  in-use indicators  59 - 56 , respectively. Here the TDMAs are used sequentially from the TDMA 1  to TDMA 4 . 
     The use of the TLI recording direction of  FIG. 4D  is an effective way to eliminate interference with an Optimum Power Calibration (OPC) area (not shown) disposed adjacently to the corresponding CDMA in case the TLI exists at a head portion of the TDMA 0  as shown in  FIG. 7 , which will be later described. 
     As an example of use of the TLI of  FIG. 4D , in  FIG. 4E , if the fourth and third TLI clusters  55   d  and  55   c  are in the recorded state, it means that the TDMA 0  and TDMA 1  are full and the usable TDMA (in-use) is the TDMA 2 . 
       FIGS. 5A to 5C  illustrate the structure of a TLI according to a second embodiment of the present invention. In this embodiment, the TLI indicates which TDMA is the in-use TDMA by indicating which TDMA(s) are full. More specifically,  FIG. 5A  illustrates the TLI structure of the single-layer write-once optical disc and  FIGS. 5B and 5C  illustrate the TLI structure of the dual-layer write-once optical disc. In these examples, assume that the TDMAs are used sequentially from the TDMA 0  to the TDMA 1  (single-layer disc), or to the TDMA 4  (dual-layer disc) as discussed above. 
     As shown in  FIG. 5A , in the example of the single-layer disc, a single cluster  62   a  is allocated for a TLI  62 . This cluster  62   a  functions as a TDMA 0  full indicator  63 . In other words, if the TDMA 0  is full, the TLI cluster  62   a  (TDMA 0  full indicator  63 ) is indicated as being in the recorded state. This means that the TDMA 1  is the in-use TDMA and can be used. If the TLI cluster  62   a  is not in the recorded state, it means that the TDMA 0  is not yet fully used up and is available for use. That is, the TDMA 0  is the in-use TDMA and can be used. 
     As shown in  FIG. 5B , in the dual-layers write-once disc, first through fourth clusters  65   a - 65   d  are allocated for a TLI  65  and are recorded sequentially in that order in this example. The first to fourth cluster  65   a - 65   d  correspond to the TDMA 0  to TDMA 3 , respectively, and function as TDMA 0 -TMDA 3  full indicators  66 - 69 , respectively. Each TLI cluster indicates whether or not the corresponding TDMA if full. 
     Accordingly, for instance, whenever the TDMA 0  to TDMA 3  are full, all four clusters  65   a - 65   d  of the TLI  65  would be in the recorded state, which means the TDMA 4  is the in-use TDMA. If no TLI cluster is in the recorded state, it means that the TDMA 0  is the in-use TDMA. If only the first TLI cluster  65   a  is in the recorded state, it means that the TDMA 0  is full and the in-use-TDMA is the TDMA 1 . If only the first and second TLI clusters  65   a  and  65   b  are in the recorded state as shown in  FIG. 5C , it means that the TDMA 0  and TDMA 1  are fully used and the TDMA 2  is currently available for use. 
       FIGS. 6A to 6C  illustrate the structure of a TLI according to a third embodiment of the present invention. In the third embodiment, the TLI indicates which TDMA is the in-use TDMA by indicating which TDMA(s) are full. A difference from the second embodiment is that the TLI includes an additional TLI cluster. In the example of  FIGS. 6A-6C , assume that the TDMAs are used sequentially from the TDMA 0  to the TDMA 1  (single-layer disc), or to the TDMA 4  (dual-layer disc) as discussed above. 
     As shown in  FIG. 6A , in the example of the single-layer disc, two clusters  72   a  and  72   b  are allocated for a TLI  72 . The first and second TLI clusters  72   a  and  72   b  function respectively as a TDMA 0  full indicator  73  and a TDMA 1  full indicator  74 . Accordingly, if only the TDMA 0  is full, the first TLI cluster  72   a  (TDMA 0  full indicator  73 ) alone is indicated as being in the recorded state. This means that the TDMA 1  is the in-use TDMA and can be used. If the first TLI cluster  72   a  is not in the recorded state, it means that the TDMA 0  is not yet full and is available for use. That is, the TDMA 0  is the in-use TDMA and can be used. If both the first and second TLI clusters  72   a  and  72   a  are in the recorded state, then the TDMA 0  and TDMA 1  are all full, which means there is no TDMA available for recording management information. In this case, the disc should be closed/finalized. 
     As shown in  FIG. 6B , in the dual-layers write-once disc, first through fifth clusters  75   a - 75   e  are allocated for a TLI  75  and are recorded sequentially in that order in this example. The first to fifth cluster  75   a - 75   e  correspond to the TDMA 0  to TDMA 4 , respectively, and function as TDMA 0 -TMDA 4  full indicators  76 - 80 , respectively. Each TLI cluster indicates whether or not the corresponding TDMA if full. 
     Accordingly, for instance, if no TLI cluster is in the recorded state, it means that the TDMA 0  is the in-use TDMA. If only the first TLI cluster  75   a  is in the recorded state, it means that the TDMA 0  is full and the in-use-TDMA is the TDMA 1 . If only the first and second TLI clusters  75   a  and  75   b  are in the recorded state, it means that the TDMA 0  and TDMA 1  are fully used and the TDMA 2  is currently available for use. If all five TLI clusters  75   a - 75   e  are in the recorded state as shown in  FIG. 6C , it means that the TDMA 0  to the TDMA 4  are all fully used up and there is no usable TDMA. In this case, since the corresponding disc has no area for recording the TDMS information therein, the disc is finalized/closed. 
       FIGS. 5A to 6C  illustrate the TLI used in a sequence starting from the TLI cluster having a low PSN to the TLI cluster having a high PSN. However, the recording direction of the TLI in  FIGS. 5A-6C  can be changed so that the TLI clusters are used sequentially in the order of decreasing address as shown in  FIGS. 4D and 4E . 
     As discussed previously, the TLI (e.g., as shown in  FIGS. 4A-6C ) can be located in the lead-in area of the single layer or dual-layer disc as shown in  FIGS. 2A and 2B .  FIGS. 7 to 9  now illustrate different locations at which the management information (TLI) can be recorded on the disc according to an embodiment of the present invention. As shown in the examples of  FIGS. 2A ,  2 B and  7 - 9 , any location of the TLI on the disc is acceptable if it is located within an area which a recording/reproducing apparatus can initially recognize as the management area. In this regard, the data area of the disc may be excluded. 
     For instance, as shown in  FIG. 7 , the TLI is provided at the head portion of the TDMA 0  on a single-layer (Layer  0 ) write-once optical disc or on a dual layer (Layers  0  and  1 ) write-once optical disc, such as a single-layer or dual-layer BD-WO. In the alternative, as shown in  FIG. 8 , the TLI can be provided at the end portion of the TDMA 0  of the single-layer/dual-layer write-once disc. As another alternative, as shown in  FIG. 9 , the TLI can be provided within one, some or each of the DMAs of the single-layer/dual-layer write-once disc. 
       FIGS. 10A and 10B  illustrate two examples of different contents of the TLI according to an embodiment of the present invention. Although  FIGS. 10A and 10B  show one TLI cluster, each cluster of the TLI can have the same content structure. Particularly,  FIGS. 10A  and  10 B are examples of recording certain real data into the TLI cluster(s) to selectively place the TLI cluster(s) into the recorded state. Some or all of such real data recorded in the TLI can be directly used to indicate whether or not the TLI cluster(s) is in the recorded state so as to identify the in-use TDMA as discussed above. The use of such real data has an advantage in that additional relevant information can be provided by the TLI in addition to the indication of the current in-use TDMA. It should be noted, however, that dummy data or any other designated signals can be recorded into the TLI cluster(s) to indicate the recorded/unrecorded state of the TLI cluster(s). The TLI content structures of  FIGS. 10A and 10B  are applicable to the TLI and disc structures shown in  FIGS. 2A-9  and  11 A- 13 B. 
     According to one example as shown in  FIG. 10A , the TLI cluster, which corresponds to a particular TDMA as discussed above, includes the latest TDDS information associated with the TDMA corresponding to the TLI cluster, in addition to the information indicating whether the corresponding TDMA is the in-use TDMA. The features of  FIG. 10A  are particularly useful in the second embodiment ( FIGS. 5A to 5C ) and the third embodiment ( FIGS. 6A to 6C ). For example, in case where the last TDDS is recorded in the last cluster of each TDMA, the TDMA including the latest TDDS and the in-use-TDMA can be different from each other, which in turn can cause errors when accessing the disc. By providing the additional information in the TLI as in  FIG. 10A , such an error can be prevented. 
     A detailed description of this situation is as follows by referring to  FIG. 10A . First, assume that the TLI is recorded in cluster units, a cluster being the minimal recording-unit. In the first sector (Sector  0 ) of the TLI cluster having 32 sectors, there exist an identification field  82  (“TLI identifier”) for allowing the recognition of the TLI information, a TLI format information field  83  (“TLI format”) related with a version of the current disc, and a TLI update count field  84  (“TLI update count”) for increasing a count value by 1 whenever the TLI is updated. The update count field  84  can also be used even as the information for indicating how many clusters may be present within the TLI. Further, there exists a TDDS location field  85  (“Latest TDDS location”) for providing information on the TDMA in which the latest TDDS information is located. 
     The remaining area  86  of the first sector (Sector 0 ) of the TLI cluster is used to indicate the recorded or unrecorded state of the TLI cluster by using a predetermined value (for example, setting the field to “00h”). For instance, if the remaining area  86  of Sector  0  of the TLI cluster has certain designated recording, that the TLI cluster can be said to be in the recorded state to indicate the usage status of the corresponding TDMA as discussed above in connection with  FIGS. 4A-6C . 
     The TDDS location field  85  in the first sector (Sector  0 ) of the TLI cluster identifies a TDMA in which the latest TDDS information is recorded irrespective of whether or not that TDMA is fully used up. For example, the values of this field  85  can be defined so that “0000 0000b” means the latest TDDS exists in the TDMA 0 , “0000 0001b” means the latest TDDS exists in the TDMA 2 , “0000 0011b” means the latest TDDS exists in the TDMA 3 , and “0000 001b” means the latest TDDS exists in the TDMA 4 . Other examples are possible. Accordingly, as an example, if the first cluster within the TLI alone is in the recorded state (e.g., the area  86  of the first TLI cluster  65   a  in  FIG. 5B  is in the recorded state) and the TDDS location field  84  (i.e., of the first TLI cluster  65   a  in  FIG. 5B ) has a value of “0000 0000b”, it means the usable TDMA is the TDMA 1 , but the last updated TDDS (latest TDDS information) is located within the TDMA 0  on the disc. 
     In addition, the latest TDDS information is recorded into a TDDS information field  87  (“Latest TDDS”) of the second sector (Sector  1  of the TLI cluster). As a result, the TLI can be utilized even for recovering the latest TDDS information directly. This is advantageous since, even if the latest TDDS information recorded in the latest TDMA as part of the TDMS information is damaged, the important TDDS information will not be lost since it can recovered from the TLI recorded in the TDMA 0 . Some or all of the remaining sectors ( 88 ) of the TLI cluster can have a copy of the latest TDDS information stored in the TDDS information field  87 . Each TDDS information is recorded in one sector size. Thus, for instance, if 3 sectors of the TLI cluster are each recorded with the same latest TDDS information, this means that the latest TDDS information is stored three times in the TLI. 
     The latest TDDS information stored in the field  87  of the TLI cluster can be the last TDDS information or the first TDDS information. For instance, if the TLI cluster utilizes a TDMA in-use indicator instead of a TDMA full indicator and the TDMA corresponding to the TLI cluster becomes the in-use TDMA, then recording in the field  86  is made to indicate that the corresponding TDMA is currently in use. At this time, the first TDDS information recorded in the corresponding TDMA is copied and recorded into the TDDS information field  87  of the TLI cluster as the latest TDDS information. The first TDDS information is recorded in the field  87  because the corresponding TDMA is still in use and is not full at that time. 
     On the other hand, if the TLI cluster utilizes a TDMA full indicator instead of a TDMA in-use indicator and the TDMA corresponding to the TLI cluster becomes full, then recording in the field  86  is made to indicate that the corresponding TDMA is full. At this time, the last TDDS information (in the last sector) recorded in the corresponding TDMA is copied and recorded into the TDDS information field  87  of the TLI cluster as the latest TDDS information. The last TDDS information of the corresponding TDMA is recorded in the field  87  because the corresponding TDMA is full and no additional TDDS information cannot be recorded into the corresponding TDMA. 
     Accordingly, according to a time point when the TLI is updated, the latest TDDS information recorded in the TLI can be the last TDDS recorded within the corresponding TDMA (e.g., when the corresponding TDMA is full), or can be the first TDDS recorded within the in-use-TDMA (i.e., when the corresponding TDMA is currently available for use). 
     As another example, the latest TDDS information can be copied up to 32 times into the TLI cluster. Any remaining sector of the TLI cluster can be set to a certain value such as 00h if it is not used. Since each TDDS information recording is allotted with one sector size, this means the entire TLI cluster can be recorded with the same latest TDDS information up to 32 times as shown in  FIG. 10B . Again, depending on the type (in-use or full) of indicator used in the TLI cluster, the latest TDDS information can be the first or last TDDS information recorded in the corresponding TDMA as discussed above. In the example of  FIG. 10B , the recording of the latest TDDS information is directly used as the TDMA in-use/full indicator of the TLI cluster. This is an example of using the recording of real data (such as the TDDS information) in the TLI cluster to selectively indicate whether or not the TLI cluster is in the recorded state. Thus, the TLI cluster, not only indicates which TDMA is the in-use TDMA, but also provides the latest TDDS information associated with the corresponding TDMA. 
     The TLI content structure shown in  FIG. 10B  is useful in the first embodiment ( FIGS. 4A to 4E ). For example, if the in-use-TDMA is the TDMA 1 , the corresponding TLI cluster is placed in the recorded state. At this time, the first TDDS information recorded in the corresponding TDMA 1  is recorded in that TLI cluster. 
       FIG. 11A to 13B  illustrate the disc structure and the TLI structure according to another embodiment of the present invention. In this embodiment, in case where a spare area (SA) is allocated in an expanded SA mode, the location of the in-use-TDMA is not only indicated, but also an in-use duration/area is indicated among the areas/durations of the TDMA existing within the expanded spare area. Particularly,  FIGS. 11A and 11B  illustrate the structure and use of a TLI in the single-layer write-once optical disc, and  FIGS. 12A-13B  illustrate the structure and use of a TLI in the dual-layer write-once optical disc. In these examples, the in-use indicators, in stead of the full indicators, are used in the TLI. 
     More specifically,  FIG. 11A  illustrates the structure of the signal-layer write-once optical disc having an expanded spare area (SA) and the TDMA 0  and TDMA 1  used in that sequence. The expanded SA or the expansion of the spare area means that the spare area (e.g., OSA 0 ) existing following the end of the user data area is allocated with the size falling within 50% of the maximal disc recording capacity by considering a future utilization when the disc is initialized. As the outer spare area (OSA 0 ) is expanded, the TDMA 1  existing within the outer spare area (OSA 0 ) is expanded together. 
     In case where the TDMA 1  is expanded in a specific size, the corresponding areas of the TDMA 1  can be expanded accordingly. The expanded TMDA 1  areas are respectively indicated as “M 1 ”, “M 2 ” and “M 3 ” in  FIGS. 11A and 11B . In this case, the TLI is divided into a portion  90  (“TLI 1 ”) for indicating which TDMA is the in-use TDMA and a portion  91  (“TLI 2 ”) for indicating a specific duration within the expanded TDMA 1 . The TLI 1  is has the size of one cluster, whereas the TLI 2  has the size of two clusters. 
     If the TDMA 1  has a greatly larger size than the TDMA 0 , e.g., due to the SA expansion and if the TLI  90  (without the portion  91 ) alone is allocated as the TLI, then the TDMA 1  may need to be scanned from the beginning to locate the last recorded location within the TDMA 1  because of its large size when the TDMA 1  becomes the in-use TDMA. This, however, can cause a drawback in that a long access time is required. Therefore, the present invention according to this embodiment divides the expanded TDMA 1  into a plurality of durations (or areas), and in case where the corresponding TDMA 1  duration/area is fully used, this status is indicated in the TLI by the portion  91 . This can reduce the disc access time significantly. 
     For instance, in  FIG. 11A , assume that the expanded TDMA 1  is divided into three same-sized durations/areas (M 1 , M 2  and M 3 ). Two clusters  91   a  and  91   b  are then allocated for the recording of the TLI 2  ( 91 ) as shown in  FIG. 11B  as an example. The two clusters  91   a  and  91   b  of the TLI 2  ( 91 ) correspond respectively to the M 3  and M 2  of the TDMA 1  and indicate whether the corresponding area (M 3  or M 2 ) is currently in-use. The manner in which the clusters  91   a  and  91   b  are used to indicate the availability of the different TDMA areas/durations can be the same as the different ways of indicating the usage status of each TDMA as discussed above in connection with  FIGS. 4A-6C  and  10 A- 10 B. For instance, if the TLI 1  ( 90 ) indicates that the TDMA 1  is the in-use TDMA, the M 2 -TDMA 1  in-use indicator ( 91   b ) indicates whether or not the M 2  of the TDMA 1  is currently the in-use TDMA area; and the M 3 -TDMA 1  in-use indicator ( 91   a ) indicates whether or not the M 3  of the TDMA 1  is currently the in-use TDMA area out of the TDMA 1 . As an example, if the TLI 1  ( 90 ) and both clusters ( 91   a  and  91   b ) of the TLI 2  ( 91 ) are detected to be in the recorded state, this means that the M 3  of the TDMA 1  is currently the in-use area of the TDMA 1 . 
     If the expanded TDMA 1  is divided into an “m” number of the same-sized durations/areas (M 1 , M 2 , . . . , Mm), the (m−1) number of clusters are allocated for the recording of the TLI 2  ( 91 ). Although the TLI 2  is used to indicate the usage status of the areas of the TDMA 1  in the example of  FIG. 11B , the TLI 2  can be used to indicate the usage status of the areas of any TDMA that is expanded according to the expansion of the corresponding SA. 
     In  FIGS. 11A and 11B , the location at which the TLI is recorded on the disc will be within a specific management area, e.g., as shown in any one of  FIGS. 7 to 9 . However, for description convenience, the TLI (=TLI 1 +TLI 2 ) is shown in  FIG. 11A  to be located at the end portion of the TDMA 0 , for example. For description convenience, the TLI structure illustrates in  FIG. 11B  the case where the in-use TDMA is indicated as shown in the first embodiment ( FIGS. 4A to 4E ). 
       FIG. 12A  illustrates the structure of a dual-layer write-once optical disc having an expanded SA and the TDMA 0 -TMDA 4 . In the dual-layer optical disc, the spare area existing following the end portion of the user data area is the inner spare area (ISA 1 ) at the second recording layer (Layer 1 ). Therefore, the spare area (ISA 1 ) may be expanded to have the size falling within 50% of the maximal disc recording capacity. As the spare area (ISA 1 ) is expanded, the TDMA 4  existing within the spare area (ISA 1 ) is also expanded together. It is also possible to expand any other variable spare area on the disc with the TDMA therein also expanded. 
     As shown in  FIG. 12A , in case where the TDMA 4  is expanded to a specific size, the TDMA 4  is divided into a specific number of same-sized durations/areas. These durations/areas are respectively identified as N 1 , N 2 , . . . , N 5 . Accordingly, the TDMA 0  includes a TLI as shown in  FIG. 12B . The TLI includes a TLI 1  ( 93 ) for indicating which TDMA is the in-use TDMA by using four clusters  93   a - 93   d , and a TLI 2  ( 94 ) for indicating the specific usage status of the durations/areas of the expanded TDMA 4  by using four clusters  94   a - 94   d . If the expanded TDMA 4  is divided into an “n” number of the same-sized durations/areas (N 1 , N 2 , . . . , Nn) as described in  FIGS. 12A and 12B , the (n−1) number of clusters is allocated for recording of the TLI 2  ( 94 ). 
     The first to fourth clusters  93   a - 93   d  of the TLI 1  ( 93 ) correspond respectively to the TDMA 4 -TDMA 1  and function respectively as the TDMA 4 -TDMA 1  in-use indicators. The first to fourth clusters  94   a - 94   d  of the TLI 2  ( 94 ) correspond respectively to the N 5 -N 2  of the TDMA 1  and indicate whether the corresponding area (N 5 , N 4 , N 3  or N 2 ) is currently in-use. The manner in which these TLI clusters  93  and  94  are used to indicate the availability of the different TDMA and TDMA areas/durations can be the same as the different ways of indicating the usage status of each TDMA as discussed above in connection with  FIGS. 4A-6C  and  10 A- 10 B. 
     In  FIGS. 12A and 12B , the location at which the TLI is recorded on the disc will be within a specific management area, e.g., as shown in any one of  FIGS. 7 to 9 . However, for description convenience, the TLI (=TLI 1 +TLI 2 ) is shown in  FIG. 12A  to be located at the end portion of the TDMA 0 , for example. For description convenience, the TLI structure illustrates in  FIG. 12B  the case where the in-use TDMA is indicated as shown in the first embodiment ( FIGS. 4A to 4E ). 
     Although the TLI 2  ( 94 ) is used to indicate the usage status of the areas of the TDMA 4  in the example of  FIG. 12B , the TLI 2  can be used to indicate the usage status of the areas of any TDMA that is expanded according to the expansion of the corresponding SA. 
       FIGS. 13A and 13B  illustrate an example of how the TLI in  FIGS. 12A and 12B  can be used. 
     As shown in  FIG. 13A , assume that the TDMA 0 , the TDMA 1 , the TDMA 2  and the TDMA 3  of the disc are currently fully used up and that it is currently in use of a specific duration/area of the last TDMA 4 , for example, the N 3  duration. 
     As shown in  FIG. 13B , since the TDMA 0 , the TDMA 1 , the TDMA 2  and the TDMA 3  are full and the last TDMA 4  is currently in use (i.e., the TDMA 4  is the in-use TDMA), the four clusters  93   a - 93   d  of the TLI 1  ( 93 ) are recorded (e.g., with real or dummy data) to be in the recorded state. Further, since the N 1  and N 2  durations/areas of the TDMA 4  are full, then the third and fourth clusters  94   c  and  94   d  of the TLI 2  ( 94 ) are placed to be in the recorded state to indicate that the N 3  of the TDMA 4  is current in-use. 
       FIG. 14  illustrates a disc initialization method according to an embodiment of the present invention. This method can be implemented in any disc structure and TLI structure discussed herein. 
     Referring to  FIG. 14 , when the disc is initialized (S 119 ), a user or system determines the spare area mode of the disc (S 120 ). This can be done using any existing technique, e.g., based on user input or a mode signal/data recorded on the disc. If the spare area mode is in the “normal” mode, the TLI is allocated on the disc with a size one less (x−1) than the number (x) of TDMAs allocated on the disc ( FIGS. 4A-5C ), or the TLI is allocated on the disc with the same number (x) as the TDMA allocation number (x) ( FIGS. 6A-6C ) (S 121 ). 
     If the spare area mode is determined to be in the “expand” mode at step S 120 , the size of the TDMA existing within the expanded spare area is expanded and the expanded spare area is divided into a specific number (y) of the same-sized durations/areas. The TLI 2  is allocated on the disc with the size one less (y−1) than the divided specific number (y) (S 122 ). In this case, similarly, the TLI  1  is allocated on the disc with the size one less (x−1) than the total number (x) of TDMAs allocated on the disc (S 122 ). In this regard, steps S 122  and S 123  can be implemented according to the TLI structure discussed in connection with  FIGS. 11A-13B . 
     The method of  FIG. 14  and any other method discussed herein according to the embodiments of the present invention can be implemented in any disc/TLI structure discussed herein. 
       FIG. 15  illustrates a recording/reproducing apparatus according to an embodiment of the present invention. The methods of the present invention can be implemented by the apparatus of  FIG. 15  or other suitable device/system. The recording/reproducing apparatus includes a recording/reproducing unit  10  for performing reproduction and/or recording from/on an optical disc, and a control unit (or host)  20  for controlling the recording/reproducing unit  10 . The control unit  20  sends a record command or a reproduce command for a specific area on the disc to the reproducing unit  10 . The recording/reproducing unit  10  performs the recording/reproduction in the specific area according to the command of the control unit  20 . The recording/reproducing unit  10  can employ an optical drive. 
     The recording/reproducing unit  10  can include an interface unit  12  for performing communication with an external device such as the control unit  20 ; a pickup unit  11  for directly recording or reproducing data to/from the optical disc; a data processor  13  for receiving the reproduction signal from the pickup unit  11  to convert the receive signal into appropriate signal values, or for modulating a to-be-recorded signal into an appropriate recording signal for the optical disc; a servo unit  14  for controlling the pickup unit  11  to precisely read the signals from the optical disc, or to precisely record the signals on the optical disc; a memory  15  for temporarily storing a variety of information including the management information and data; and a microprocessor  16  for controlling the operations and structural elements within the unit  10 . 
     An example of a description of a disc reproduction method using the inventive TLI in the apparatus of  FIG. 15  is as follows. 
     If a disc is loaded, the recording/reproducing unit  10  obtains a variety of recorded disc information from the loaded disc. Specifically, if the loaded disc is a write-once optical disc, for example, a BD-WO as discussed herein, the microprocessor  16  checks the recorded/unrecorded state of the TLI cluster(s) at a designated location (e.g., from the head portion of the TDMA 0 ) within the management area to obtain the last recorded location within the in-use-TDMA. 
     Accordingly, after the location of the in-use-TDMA is obtained by accessing the TLI, the in-use-TDMA is scanned from the beginning to obtain the last recorded TDMS information, or the TDDS information may be obtained from the TLI. A portion of the obtained TDMS information is transmitted to the control unit  20 , and the control unit  20  uses the transmitted TDMS information to transmit again the reproduction command to the recording/reproducing unit  10 , thereby performing the reproduction using the recording/reproducing unit  10 . 
     An example of the method of recording the inventive TLI using the apparatus of  FIG. 15  is described as follows. 
     The microprocessor  16  records the TDMS information in the plurality of TDMAs, which are determined and used in a specific use sequence. For example, first the TDMA 0  begins to be used. If the TDMA 0  is fully used up, a specific TLI cluster is recorded to be in the recorded state as discussed above, whereby the TDMA 1  is indicated as the in-use TDMA. 
     When the disc is in an idle state or in a disc eject state after the disc recording is all finished, the location of the in-use-TDMA is checked such that the above operation can change the specific cluster within the corresponding TLI to be in a batch recording state. 
     As described above, the present invention has an advantage in that in the write-once optical disc, the access time to obtain the location of the in-use-TDMA is reduced significantly, thereby greatly enhancing the use efficiency of the write-once optical disc using the TDMAs. Further, other information such as the latest TDDS information can be recorded in the TLI, which can be accessed and used as needed, especially if the TDDS information stored in the TDMAs is damaged. 
     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.