Abstract:
The method includes simultaneously displaying first supplementary data (e.g., sub-picture data) and second supplementary data (e.g., caption data). The first supplementary data and the second supplementary data are supplementary to at least one of audio data and/or video data. In embodiments, the language of the first supplementary data may is different from the language of the second supplementary data. These embodiments are advantageous, as the connection between the first supplementary data and the second supplementary data may serve as a translation and assist in an understanding of context of the video data and/or the audio data. Accordingly, a viewer, whose native language, is not the language of the video data or audio data may be able to use the combination of the first supplementary and second supplementary data to learn the language of the video data or audio data.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention generally relates to playback devices.  
           [0003]    2. Background of the Related Art  
           [0004]    Radio and televisions are examples of devices that output audio and/or video signals. These audio and/or video signals may be in the form of radio programs, television programs, or movies. It is often desirable for a listener or a viewer to record a radio or television program. This desire is based on the ability to replay or playback the radio or television program later.  
           [0005]    Some listeners or viewers of radio and television programs may not have a complete understanding of their radio or television program due to a language barrier. This language barrier may be that the radio or television program is in a language different from the listener or viewer&#39;s native language. Accordingly, there has been a long felt need for a listener or a viewer to enhance their understanding of a radio or television program that is in a different language than their native language.  
         SUMMARY OF THE INVENTION  
         [0006]    Objects of the present invention are to at least overcome these disadvantages of the related art. Embodiments of the present invention relate to a method. The method comprises simultaneously displaying first supplementary data (e.g., sub-picture data) and second supplementary data (e.g., caption data). The first supplementary data and the second supplementary data are supplementary to at least one of audio data and/or video data. In embodiments, the language of the first supplementary data may is different from the language of the second supplementary data. These embodiments are advantageous, as the connection between the first supplementary data and the second supplementary data may serve as a translation and assist in an understanding of context of the video data and/or the audio data. Accordingly, a viewer, whose native language, is not the language of the video data or audio data may be able to use the combination of the first supplementary and second supplementary data to learn the language of the video data or audio data.  
           [0007]    Embodiments of the present invention relate to a method comprising displaying an accumulation of supplementary data associated with at least one of video and audio data. In some embodiments, a user viewing audio and/or video data, can view a compilation of the supplementary data to review the entire context in their native language of the video data and/or audio data. In embodiments, the accumulation of supplementary data can be searched by a keyword. In embodiments, a portion of the audio data or video data can be referenced based on a searched word in the supplementary data. Accordingly, users, particularly users learning a new language, can utilize supplementary data to learn the language of the audio data and/or video data.  
           [0008]    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 objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    [0009]FIG. 1 is an exemplary block diagram illustrating a configuration of an optical disc device.  
         [0010]    [0010]FIG. 2 is an exemplary diagram illustrating a structure of a sub-picture unit recorded in a DVD.  
         [0011]    [0011]FIG. 3 is an exemplary diagram illustrating a relation between a corresponding sub-picture unit and sub-picture pack in a DVD.  
         [0012]    [0012]FIG. 4 is an exemplary diagram illustrating display-on and display-off states of a sub-picture unit in a DVD.  
         [0013]    FIGS.  5  to  8  are exemplary diagrams respectively illustrating different examples of sub-picture data searched for and repeatedly reproduced in an optical disc device.  
         [0014]    [0014]FIG. 9 is an exemplary block diagram illustrating a configuration of an optical disc device.  
         [0015]    [0015]FIG. 10 is an exemplary diagram illustrating a recording format of caption data.  
         [0016]    [0016]FIG. 11 is an exemplary diagram illustrating a structure of a caption frame.  
         [0017]    [0017]FIG. 12 is an exemplary diagram illustrating control code and text data of caption data.  
         [0018]    [0018]FIG. 13 is an exemplary flow chart illustrating a multi-text displaying method.  
         [0019]    [0019]FIG. 14 is an exemplary view illustrating a sub-picture text image and caption text image displayed on a screen in accordance with a multi-text displaying method.  
         [0020]    [0020]FIG. 15 is an exemplary diagram illustrating, in the form of a table, the caption data and search information.  
         [0021]    [0021]FIGS. 16 a  and  16   b  are exemplary flow charts respectively illustrating caption data reproducing and searching procedures.  
         [0022]    [0022]FIGS. 17 and 18 are exemplary views respectively illustrating TV screens corresponding to a caption learning mode. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0023]    An optical disc device (e.g., a DVD player) may be configured to read out video and/or audio data recorded as main titles on a high-density optical disc. In other words, in a DVD, read-out data is reproduced as digital images and/or audio signals. Further, a DVD may display a high quality picture and a high quality tone through an output appliance (e.g., a general TV).  
         [0024]    In embodiments, DVDs may be recorded with caption information of diverse languages as sub-picture data. Sub-picture data may be randomly recorded as subtitles in a certain sector of a DVD so that they are reproduced and outputted in association with video and/or audio data corresponding to main titles. Caption data may be for hearing impaired persons. Caption data may also be used for other purposes (e.g., learning languages). Caption data may be recorded on a DVD to be associated with a video data stream of a main title. Accordingly, when video and/or audio data is read out during reproduction in a DVD player, sub-picture data and/or caption data may be simultaneously read out during reproduction. A user of a DVD player may view video data of a main title while identifying sub-picture data (e.g., caption information of diverse languages). A DVD player may read out and reproduce caption information from a DVD through a sub screen of the TV. Accordingly, it may be possible to efficiently enhance foreign language learning ability using an optical disk device.  
         [0025]    A user may desire to search for and reproduce again a previously reproduced caption information during a language learning procedure carried out while viewing the caption information of diverse languages reproduced from an optical disc (e.g., a DVD). A user may desire to repeatedly reproduce a desired block of caption information. Accordingly, it may be necessary for a user to directly search for a position where sub-picture data of caption information is recorded through several key inputting manipulations. Accordingly, there may be inconveniences in use and a degradation in learning efficiency.  
         [0026]    Embodiments of the present invention relate to a sub-picture data reproducing method. Some embodiments relate to an optical disc device (e.g., a DVD player). As illustrated in FIG. 1, an exemplary DVD player may include an optical pickup (P/U)  11 , a radio frequency (RF) signal processing unit  12 , a digital signal processing unit  13 , a video decoder  14 , and/or an audio decoder  15 . The DVD player may be for reading out and reproducing video and/or audio data streams recorded on an optical disc  10 . A DVD player may also include a sub-picture decoder  16  for reproducing and/or signal-processing sub-picture data (e.g., caption information of diverse languages) recorded on optical disc  10 . A DVD player may include a memory  23  for storing information about recording position and reproducing time associated with a search and reproduction of sub-picture data. A DVD player may include a spindle motor  18 , a sled motor  19 , optical pickup  11 , a motor driving unit  21 , and/or a servo unit  20 . Spindle motor  18  may be for rotating an optical disc. Sled motor  19  may be for shifting the position of optical pickup  11 . Motor driving unit  21  and/or servo unit  20  may be for driving and controlling spindle motor  18  and/or sled motor  19 . Control unit  22  may be for controlling operations of a DVD player.  
         [0027]    In embodiments, in a reproducing operation, control unit  22  may compare a recording size of a current sub-picture unit reproduced for display by sub-picture decoder  16  with a recording size of an immediately previously-reproduced sub-picture unit. When compared sub-picture units are not equal, control unit  22  may determine that current sub-picture data is new sub-picture data. In this case, control unit  22  may store, as search information, the recording size, recording start position information, and/or presentation time stamp information of the current sub-picture unit in memory  23 . This search information may be stored and managed as a bookmark. FIG. 2 is an exemplary illustration of a sub-picture unit having an exemplary structure consisting of a sub-picture unit header (SPUH), pixel data (PXD), and/or a sub-picture display control sequence table (SP_DCSQT). The sub-picture unit header SPUH may include size information of 2 bytes (SPU_SZ) for representing a recording size of an associated sub-picture unit. SPUH may include start address information of 2 bytes (SP_DCSQT_SA) for representing a recording start position from which a sub-picture displayer control sequence table (SP_DCSQT) begins to be recorded. SP_DCSQT may include a plurality of sub-picture display control sequences (e.g., SP_DCSQ  0 , SP_DCSQ  1 , and/or SP_DCSQ  2 ). Sub-picture unit having the above-described structure may be read out and reproduced in the form of a sub-picture stream consisting continuous sub-picture packs (e.g., SP_PCK i, SP_PCK i+1, and SP_PCK i+2). Each sub-picture pack may have a recording size of 2,048 bytes, as exemplified in FIG. 3.  
         [0028]    As exemplified in FIG. 4, sub-picture decoder  16  may perform a decoding operation and a reproduced signal processing operation for sub-picture units. Sub-picture decoder  16  may control a display of sub-picture data to be switched on or off in accordance with a display control command designated by a sub-picture display control sequence (SP_DCSQ) to reproduce and display sub-picture data only for a part of a valid period of a sub-picture unit or stopping reproduction of sub-picture data. When sub-picture decoder  16  detects a display control command (DSP_CMD_OFF) designating a display-off during a procedure of decoding and reproducing, it stops a decoding and reproducing operation for the sub-picture data corresponding to a valid period designated by the display control command (DSP_CMD_OFF) while being stored in an internal buffer.  
         [0029]    Control unit  22  may detect information about recording size (SPU_SZ) of a current sub-picture unit reproduced and displayed by sub-picture decoder  16 , at desired intervals of time to read out the recording size (SPU_SZ) of a sub-picture unit. For example, intervals capable of detecting information about sub-picture unit header (SPUH) included in the sub-picture stream. Control unit  22  may then compare read-out recording size information with recording size information of the immediately previously reproduced and displayed sub-picture unit. When compared recording sizes are not equal, control unit  22  may discriminate that the current sub-picture data is new sub-picture data. Control unit  22  may store, in memory  23 , information about playback time of a sub-picture unit detected by sub-picture decoder  16  (PTS_of_SPU). Control unit  22  may store information about recording start position of a detected sub-picture unit (SPU_SA) as search information adapted to search for an associated sub-picture unit.  
         [0030]    In embodiments, reproduction time information and recording start position information can be stored at every sub-picture ON or OFF time point. In embodiments, a sub-picture data reproducing method for searching for sub-picture data (e.g., caption information) of diverse languages desired by the user may be based on stored search information. Embodiments relate to reproducing searched sub-picture data or repeatedly reproducing a desired block of searched sub-picture data.  
         [0031]    FIGS.  5  to  8  are exemplary illustrations of different examples of sub-picture data searched for and repeatedly reproduced in an optical disc device. During a reproducing operation, control unit  22  may search for and read out recording size information (SPU_SZ #k) of a k-th sub-picture unit currently decoded, reproduced, and/or displayed by sub-picture decoder  16  at desired intervals of time. Control unit  22  may then compare read-out recording size information (SPU_SZ #k) with recording size information (SPU_SZ #k- 1 ) of an immediately previously reproduced and displayed sub-picture unit (e.g., the k- 1 -th sub-picture unit) ({circle over (1)}). When recording size information (SPU_SZ #k) of the k-th sub-picture unit does not correspond to recording size information (SPU_SZ #k- 1 ) of the k- 1 -th sub-picture unit (SPU_SZ #k- 1 ), it may be determined that the k-th sub-picture unit, which is currently reproduced and displayed, is a new sub-picture data different from the k- 1 -th sub-picture unit. Accordingly, control unit  22  may store recording size information (SPU_SZ #k), playback time information (PTS_of_SPU #k), and/or recording start position information SPU_SA #k of the k-th sub-picture unit in the memory  23  as search information ({circle over (2)}).  
         [0032]    When a predetermined user key, (e.g., a ‘learning key’) is subsequently inputted ({circle over (3)}), control unit  22  may perform sequential sub-picture data searching and reproducing operations in accordance with embodiments of the present invention. Control unit  22  may search for and read out most recently-stored search information from memory  23  at a point in time when a ‘learning key’ is inputted. Control unit  22  may then search for a recording start position of a k-th sub-picture data corresponding to search information({circle over (4)}). Accordingly, it may be possible to reproduce (play back) and/or display sub-picture units having time continuity. For example, sub-picture units corresponding to caption information of a complete sentence such as “How are you?”, starting from a start portion of a start sub-picture unit.  
         [0033]    In accordance with embodiments of the present invention, when a ‘learning key’ from a user is inputted ({circle over (3)}), control unit  22  temporarily stores recording position of current sub-picture data reproduced and displayed at a point of time when a ‘learning key’ is inputted, as illustrated in exemplary FIG. 6. Control unit  22  may also search for and read out most recently-stored search information from memory  23  at a point in time when a ‘learning key’ is inputted. Control unit  22  may then search for a recording start position of a k-th sub-picture data corresponding to search information ({circle over (4)}). Reproduction and display of sub-picture data may then be carried out, starting from a recording start position of a searched k-th sub-picture data. Control unit  22  may perform sequential block repeat playback operations for repeatedly playing back, at least one time, a desired sub-picture data block between point of time ({circle over (4)}) and point of time ({circle over (3)}). In embodiments, the number of repeat times is set by a user. In accordance with embodiments of the present invention, when a ‘learning key’ from a user is inputted ({circle over (3)}), control unit  22  may search for and read out most recently-stored search information from memory  23  at a point in time when the ‘learning key’ was inputted. Control unit  22  may search for a recording start position of a k-th sub-picture data corresponding to search information ({circle over (4)}) and may then reproduce and display sub-picture data starting from the recording start position of the searched k-th sub-picture data, as illustrated in exemplary FIG. 7. Control unit  22  may perform sequential block repeat playback operations until a display control command (DSP_CMD_OFF) designating a display-off of read-out and reproduced sub-picture data is detected ({circle over (6)}). Control unit  22  may performs sequential block repeat playback operations for repeatedly playing back at least one time, a desired sub-picture data block between point of time ({circle over (4)}) and point of time ({circle over (6)}) in accordance with the number of repeat times set by a user.  
         [0034]    In accordance with embodiments of the present invention, when a ‘learning key’ from a user is inputted ({circle over (3)}), control unit  22  searches for and reads out most recently-stored search information from memory  23  at the point of time when a ‘learning key’ is inputted. Control unit  22  may search for a recording start position of a k-th sub-picture data corresponding to search information ({circle over (4)}). Control unit  22  may then reproduce and display sub-picture data starting from a recording start position of a searched k-th sub-picture data, as illustrated in exemplary FIG. 8. When a ‘learning key’ is inputted one more time, control unit  22  may perform sequential sub-picture data searching and reproducing operations. Control unit  22  may search memory  23  and read out playback time information or recording start position information of a previously reproduced and displayed k- 1 -th sub-picture data ({circle over (6)}). Control unit  22  may reproduce and display sub-picture data, starting from a recording start position of a searched k- 1 -th sub-picture data. In accordance with a number of repeated ‘learning key’ inputs, a corresponding sub-picture data may be searched for and reproduced. Accordingly, it may be possible to more rapidly and accurately search for and repeatedly play back a previously reproduced and displayed sub-picture data. Therefore, it may be possible to easily search for and play back sub-picture data of a desired caption information without any requirement for a user to enter a key input several times.  
         [0035]    Embodiments of the present invention relate to a multi-text displaying method. In embodiments, the method is applicable to an optical disc device (e.g., DVD player). As illustrated in exemplary FIG. 9, a DVD player may include an optical pickup (PU)  51 , an RF signal processing unit  52 , a digital signal processing unit  53 , a video decoder  54 , and/or an audio decoder  55 . A DVD player may read out and reproduce video and/or audio data streams recorded on optical disc  50 .  
         [0036]    A DVD player may also include a sub-picture decoder  56 , a caption decoder  64 , and a display buffer  65 . Sub-picture decoder  56  may be for reproducing and signal-processing sub-picture data (e.g., caption information of diverse languages) recorded on the optical disc  50 . Caption decoder  64  may be for reading out caption data included in a video data stream recorded in optical disc  50 , reproducing read-out caption data, and signal-processing read-out caption data. Display buffer  65  may be for outputting and displaying a caption image of caption data.  
         [0037]    A DVD player may further include a spindle motor  58 , a sled motor  59 , optical pickup  51 , motor driving unit  61 , servo unit  60 , control unit  62 , a memory  63 , and/or on-screen-display (OSD) generating unit  66 . Spindle motor  58  may be for rotating an optical disc. Sled motor  59  may be for shifting a position of optical pickup  51 . Motor driving unit  61  and/or servo unit  60  may be for driving and controlling spindle motor  58  and sled motor  59 . Control unit  62  may be for controlling operations. Memory  63  may be for storing information required for a control operation. On-screen-display (OSD) generating unit  66  may be for generating and outputting an OSD image.  
         [0038]    When a predetermined user key (e.g., a ‘multi-text key’) is inputted during a reproducing operation, control unit  62  may control display of text images of sub-picture data and/or caption data read out from optical disc  10  in the form of different languages. A display image may be in such a fashion that a text image of a sub-picture data may be displayed in a user&#39;s own language (e.g., the native language of a user) whereas text image of caption data is displayed in a language foreign to the user. Before control unit  62  performs a multi-text displaying operation, it may store (for backup) information about a current display environment set by a user (e.g., sub-picture data display-on/off state and language information) in memory  23 . This information may be stored so that when a multi-text displaying operation is complete, a display environment may be recovered to a display environment set by a user.  
         [0039]    Caption data may be included in a video data stream recorded as a main title in optical disc  50 . FIG. 10 is an exemplary illustration of a video sequence which is a logic file demodulated from a video data stream. As illustrated in FIG. 10, a video sequence may include a sequence header, a sequence extension, extension data, and/or user data. Caption data may be included in user data as data of a  21 st line (Line  21 _Data).  
         [0040]    As illustrated in exemplary FIG. 11, caption data read out as data of a  21 st line in the user data may be accumulatively stored in display buffer  63  in a form of a caption frame having 4 lines, and may be subsequently outputted at a single time. Display buffer  65  may detect and identify information (Start_of_Caption) representing a start of caption data from demodulated data outputted from caption decoder  64 . Display buffer  65  may be accumulatively stored, by frames, caption data received following a start of caption data. When display buffer  65  subsequently detects and identifies information (End_of_Caption) representing an end of the caption data, it outputs the accumulatively-stored caption frames at one time so that the frames are displayed in the form of a text image having a desired size.  
         [0041]    [0041]FIG. 12 is an exemplary illustration of caption data, which may be included in user data and may include a preamble control code substantially identical or similar to caption data transmitted while being included in a general analog image signal and a caption text of up to 32 characters per row. Embodiments of the present invention relate to a method for selectively demodulating text images of caption data and sub-picture data into text images of different languages. In embodiments, this is in response to a ‘multi-text’ key entered by a user. Some embodiments relate to displaying both demodulated text images on a single screen of a general TV.  
         [0042]    [0042]FIG. 13 is an exemplary flow chart illustrating a multi-text displaying method in an optical disc apparatus in accordance with embodiments of the present invention. Control unit  62  may cause an apparatus to perform a playback operation for reading out and reproducing video and/or audio data recorded on optical disc  50  (Step S 10 ). When a predetermined user key (e.g., a ‘multi-text’ key), is entered by a user during playback operation, control unit  62  may determine that a multi-text displaying operation for simultaneously displaying text images of caption data and sub-picture data has been requested (Step S 11 ). Control unit  62  may detect and identify a data playback condition set by a user before inputting a multi-text key. Data playback condition may include display-on/off of sub-picture data and language information of sub-picture data being reproduced in accordance with a selection thereof by a user. Control unit  62  may store (back-up) identified information in memory  63  (Step S 12 ).  
         [0043]    Control unit  62  may control sub-picture decoder  56  and caption decoder  64  to read out sub-picture data recorded in optical disc  50  as a subtitle (Step S 13 ). Caption data may be included in a video data stream recorded in optical disc  50  as a main title. Control unit  62  may display, on a screen, text image of caption data demodulated and signal-processed by caption decoder  64 . At substantially the same time, control unit  62  may display a text image of sub-picture data demodulated and signal-processed, by sub-picture decoder  56 . The data from sub-picture decoder  56  may use a language different from that of the text image of the caption data (e.g., a native language). A native language may be set in a process of manufacturing an optical disc device or set by a user.  
         [0044]    For example, a multi-text displaying operation may be requested under a condition in which Korean language is a native language. Text image of sub-picture data selectively displayed prior to inputting of a ‘multi-text’ key may correspond to a foreign language (e.g., French language). Control unit  62  may store in memory  63  information capable of identifying a type of language as French. Control unit  62  may detect and identify nation code information set in an optical disc device (e.g., ‘Korea’) and then read out and reproduces sub-picture data corresponding to Korean language, thereby displaying text images of Korean language. Control unit  62  may control overlapping timing of caption data and sub-picture data with a main image signal demodulated and reproduced by video decoder  54 . Text image of sub-picture data corresponding to a native language and text image of caption data corresponding to a foreign language may be simultaneously displayed on a single screen of a general TV at different positions. As illustrated in exemplary FIG. 14, simultaneous display may be in such a fashion that a text image of caption data (e.g., a text image “How are you?”) may be displayed near the top of a screen, whereas the text image of sub-picture data (e.g., “         ?” in Korean text) may be displayed near the bottom of the screen (Step S 14 ).  
         [0045]    A request to release multi-text may be made when a multi-text image is displayed (Step S 15 ). Control unit  62  may detect and identify back-up information stored in memory  63  (e.g., display-on/off state of sub-picture data and nation language information stored prior to the multi-text displaying operation) and may recover a previous condition (Step S 16 ). A user may view both a text image of a native language and a text image of a foreign language on a screen of a TV, along with a high quality video image. Accordingly, it may be possible to achieve an enhancement in language learning efficiency. Caption data representing a text image of a foreign language may be character data. An optical disc device may be equipped with an internal electronic dictionary database in order to allow a user to utilize a word search function.  
         [0046]    Caption data may be recorded in a form of data made of capital letters of the English language. In order to provide convenience to users speaking languages other than the English language and unfamiliar with English capital letter fonts, font data of English capital letters may be stored while being mapped with font data of corresponding English small letters. When caption data of English capital letters is demodulated, font data of corresponding English small letters may be stored in a memory and may be read out in order to perform a font conversion operation for converting caption data of capital letters into caption data of small letters.  
         [0047]    During a playback operation in an optical disc device (e.g., a DVD player) a caption data searching operation may be carried out. In a caption data searching operation, a control unit may read out caption data and store read-out caption data in a memory of an optical disc device. Optical disc device  21  may rapidly reproduce and output only caption data at a request of a user. Alternatively, a control unit may store, along with caption data, search information capable of searching for recording position of a video data stream including caption data. A control unit may automatically and rapidly search for a recording position where caption data corresponding to letters entered by a user is recorded on an optical disc. A control unit may then reproduce caption data.  
         [0048]    Memory  63  may store caption data read out by caption decoder  64 . Memory  63  may store search information capable of searching a recording position of a video data stream including caption data (e.g., a recording position address or presentation time stamp (PTS) of a video data stream). In memory  63 , caption data may be stored by recording units of a desired recording size (e.g., caption data entries Caption_Data_Entry) having time continuity. Search information may be a recording start position information (Start_Address) of each caption data entry (Caption_Data_Entry) and/or start presentation time stamp information (Start_PTS). Search information may have a value corresponding to a recording position information or representation time stamp information of a video data stream including leading caption data of an associated caption data entry.  
         [0049]    A user may selectively enter a particular key (e.g., a ‘caption search key’). Control unit  62  may control an OSD generating unit  66  to display a letter input window on an OSD screen of an externally-connected appliance (e.g., a general TV). Control unit  62  may perform a caption data searching operation for searching memory for caption data corresponding to letters inputted through a letter input window. A caption data search operation may read out and identify search information stored in association with searched caption data. A caption data search operation may rapidly search for a recording position of caption data on an optical disc based on an identified search information, while displaying caption data.  
         [0050]    Exemplary FIGS. 16 a  and  16   b  illustrate performance of sequential operations for reading out and reproducing video and audio data streams from an optical disc (e.g., a DVD) loaded in an optical disc player (Step S 50 ). Caption decoder  64  may search for and read out caption data included in a video data stream as user data (User_Data) (Step S 51 ). Caption decoder  64  may store caption data in memory  63  (Step S 52 ). At step S 52 , caption decoder  64  may also search for recording position information or presentation time stamp information of a video data stream included in caption data and store searched information in association with caption data.  
         [0051]    Exemplary FIG. 15 illustrates caption data stored in memory  63  by caption data entries (Caption_Data_Entry) having a time continuity while having a desired recording size. Search information may be stored in association with each caption data entry. Search information may be a video data stream including leading caption data of an associated caption data entry. A caption data entry may include a recording start position information [Start_Address] and/or start presentation time stamp information [Start_PTS] of a video object unit (VOBU) having a desired recording size. When a predetermined key (e.g., a ‘caption learning key’) is inputted, control unit  62  may determine that a caption learning mode corresponding to a caption learning key is requested by a user (Step S 53 ). In this case, control unit  62  may stop normal playback operation and may control operation of caption decoder  64 . Under control of control unit  62 , caption decoder  64  may sequentially read out caption data stored in memory  63  (Step S 54 ). Caption decoder  64  may perform a caption data reproducing operation for displaying a caption image (e.g., a text image), corresponding to the caption data through a screen of an externally-connected appliance (e.g., a general TV) (Step S 55 ).  
         [0052]    Caption data may be reproduced and outputted by being signal-processed to display a text image having a size larger than the size of a text image set to be displayed along with a video image during a normal optical disc playback operation. For example, a size of a text image may be set to be displayed in an overlapping fashion on the upper or lower portion of a general TV screen. A large-size text image may be displayed, as illustrated in exemplary FIG. 17. Accordingly, a user may easily view and identify an increased number of caption letters on the same screen.  
         [0053]    When a predetermined key, (e.g., a ‘caption search key’) is inputted, control unit  62  may determine that a caption searching mode corresponding to a caption search key is requested by a user (Step S 60 ), as illustrated in exemplary FIG. 16 b . In this case, control unit  62  may stop a normal playback operation and control OSD generating unit  66  to operate. When a key, other than a ‘caption search key’ is inputted, control unit  62  may perform a control operation to carry out an operation associated with the inputted key (Step S 70 ). When OSD generating unit  66  operates under control of control unit  62 , it may generate an OSD input window for inputting a search word (e.g., a key word) and may display the generated OSD input window on a TV screen (Step S 61 ), as illustrated in exemplary FIG. 18.  
         [0054]    When a search request key entered by a user is subsequently inputted (Step S 62 ), control unit  62  may check whether or not there is a search word entered by a user and inputted through an OSD input window (Step S 63 ). When there is a search word entered by a user, control unit  62  may perform a caption data searching operation for searching memory  63  to determine whether or not there is caption data corresponding to the search word (Step S 64 ). When memory is stored with caption data corresponding to a search word entered by a user, control unit  62  may search for and identify search information stored in association with caption data (Step S 65 ). Using identified search information (e.g., identified recording position information or presentation time stamp information) control unit  62  may search for a recording position of an associated video data stream recorded in DVD  10  (Step S 66 ).  
         [0055]    In embodiments, control unit  62  may search for and identify a recording start position information (Start_Address) of a caption data entry (Caption_Data_Entry) including caption data corresponding to a search word. Control unit  62  may control its servo unit  20  so that optical pickup  51  searches for a recording position of a video data stream having an identified recording start position information (Start_Address). Control unit  62  may cause automatic performance of a normal reproducing operation for reading out and reproducing video and/or audio data streams, starting from a searched recording position.  
         [0056]    Control unit  62  may search for and identify a start presentation time stamp information (Start_PTS) of a caption data entry (Caption_Data_Entry) including caption data corresponding to a search word. Control unit  62  may control its servo unit  20  so that optical pickup  51  searches for a recording position of a video data stream having identified start presentation time stamp information (Start_PTS). Control unit  62  may cause automatic performance of a normal reproducing operation for reading out and reproducing video and/or audio data streams, starting from a searched recording position.  
         [0057]    In accordance with embodiments of the present invention, it may be possible to rapidly output only caption data under conditions in which a normal reproducing operation is stopped. It may also be possible to automatically and rapidly search for a recording position of a video data stream where a caption data corresponding to letters desired by a user is recorded and reproduce the caption data.  
         [0058]    The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art.