Abstract:
A method for accessing an optical disk with an optical disc drive. The optical disc contains at least a session including a lead-in area and a program data area. The method for accessing the optical disk with the optical disc drive includes providing the optical disc drive an optical pickup for accessing the data on the optical disc, using the optical pickup to record a table of contents (TOC) in the lead-in area of the session of the optical disc, using the pick-up head to record descriptive data corresponding to the TOC in the lead-in area of the session, and using the optical pickup to record program data corresponding to the TOC in the program data area of the session.

Description:
BACKGROUND OF INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The invention relates to a method for accessing data on an optical disc with an optical disc drive, and more particularly, to a method for recording a table of contents and descriptive data corresponding to the table of contents to the optical disc with the optical disc drive.  
           [0003]    2. Description of the Prior Art  
           [0004]    With the constant development of computer technology, most information is transformed into digital data so that users can transmit information or record information more easily. Meanwhile, to help users record the digital data more conveniently, there are a variety of devices for recording the digital data. Take an optical disc drive and an optical disc for example. The optical drive uses the optical disc with the advantages of low-price, small size, and large capacity for recording the digital data so as to let the users conveniently record the digital data.  
           [0005]    Please refer to FIG. 1. FIG. 1 is a diagram of accessing data on an optical disc  20  with an optical disc drive  10  according to the prior art. The optical disc  20  comprises a spiral track  22  extending outward from a center to an outer edge of the optical disc  20 , and the spiral track  22  is covered with a photo-resist layer  24  (which is not shown in FIG. 1). The optical disc drive  10  comprises an optical pickup  12  used to emit a laser according to whether the data is “0” or “1”, and records the data to the optical disc  20  with the optical disc drive  10 . Therefore, the photo-resist layer  24  on the spiral track  22  of the optical disc  20  is intermittently exposed to the laser, thus, the photo-resist layer  24  is left with pits in areas that were exposed to the laser, and lands remain in the areas not exposed to the laser. According to the difference between the rates of the laser reflected from a pit and a land, the pit and the land on the optical disc  20  each can represent content of data, for example, a digital “0” and a digital “1”. On the other hand, the optical disc drive  10  also uses the optical pickup  12  to receive the reflected laser so as to read data on the optical disc  20  by analyzing the data based on the different rates of the reflected laser.  
           [0006]    According to the rules of the Orange Book, the spiral track  22  of the optical disc  20  can be divided into at least one session comprising a lead-in area, a program data area, and a lead-out area. As shown in FIG. 1, the optical disc  20  comprises at least one session  26  comprising a lead-in area  28 , a program data area  30 , and a lead-out area  32 . The program data area  30  is used to record one or a plurality of tracks, which is used to record data or audio. Generally speaking, if the session  26  is used to record data, the session  26  can only contain a track, so that the optical disc  20  can contain a plurality of tracks, and if the session  26  is totally used to record audio, the session  26  can contain a plurality of tracks, so that the optical disc  20  can still contain a plurality of tracks. The lead-in area  28  of the session  26  comprises data of amount of tracks, the beginning position of the tracks, and the length of the tracks in the program area  30  of the session  26 . These three kinds of data are generally called a table of contents (TOC). The optical disc drive  10  controls and moves the optical pickup  12  to a specific position of the optical disc  20  according to the data of the TOC so as to read data on the specific position. Because the lead-out area  32  of the session  26  is recorded with data of digital silence, the optical disc drive  10  can determine that the optical pickup  12  has read all the data on the program area  30  of the session  26  when the optical pickup  12  has read the data of digital silence on the lead-out area  32 .  
           [0007]    The lead-in area of each session of the optical disc  20  comprises 4500 sectors, and the length of each sector is 2 K bytes, so the length of the lead-in area of each session of the optical disc  20  is 9 M bytes (2 k bytes×4500=9 M bytes). According to the prior art, because the sectors of each lead-in area of the optical disc pickup  20  are only used for recording the TOC, the rest of the memory space in the sectors is wasted. Furthermore, if the optical disc  20  comprises a plurality of sessions, there will be plenty of memory space of the sectors wasted.  
         SUMMARY OF INVENTION  
         [0008]    It is therefore a primary objective of the claimed invention to provide a method for accessing data on an optical disc with an optical disc drive to solve the above-mentioned problem.  
           [0009]    According to the claimed invention, the optical disc drive is used to access the data on the optical disc that comprises at least one session. Each session comprises a lead-in area and a program data area. The claimed method comprises providing the optical disc drive with an optical pickup for accessing the data on the optical disc, using the optical pickup to record a table of contents in the lead-in area of the session of the optical disc, using the optical pickup to record descriptive data corresponding to the table of contents in the lead-in area of the session, and using the optical pickup to record program data corresponding to the table of contents in the program data area of the session.  
           [0010]    The method further comprises using the optical pickup to read the table of contents and the descriptive data on the lead-in area of the session, providing the optical disc drive with a monitor, using the optical pickup to read the program data on the program data area of the session according to the table of contents on the lead-in area of the session, and using the optical drive to execute the program data and display the descriptive data on the monitor at the same time.  
           [0011]    It is an advantage of the claimed invention that the method for accessing the data on the optical disc with the optical disc drive can use the rest of the memory space in the lead-in area of the optical disc for recording the descriptive data describing the program data on the program data area of the optical disc so that the memory space of the lead-in area can be fully utilized.  
           [0012]    These and other objectives of the present invention will no doubt obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0013]    [0013]FIG. 1 is a diagram of accessing data on an optical disc with an optical disc drive according to the prior art.  
         [0014]    [0014]FIG. 2 is a diagram of accessing data on an optical disc with an optical disc drive according to a present invention.  
         [0015]    [0015]FIG. 3 is a diagram of descriptive data recorded in a lead-in area of a session of the optical disc according to another embodiment of the present invention.  
         [0016]    [0016]FIG. 4 is a flow chart of a method for accessing data on the optical disc with the optical disc drive according to the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0017]    Please refer to FIG. 2. FIG. 2 is a diagram of accessing data on an optical disc  50  with an optical disc drive  40  according to a present invention. As with the optical disc  20  of the prior art, the optical disc  50  also comprises a spiral track  52 , and the spiral track is also covered with a photo-resist layer  54  (which is not shown in FIG. 2). The optical disc drive  40  comprises an optical pickup  42  which is used to emit laser and expose the photo-resist layer  54  on the spiral track  52  of the optical disc  50  to the laser so as to record data to the optical disc  50 . However, the optical disc drive  40  of the present invention further comprises a monitor  44 . The optical disc  50  of the present invention can be a CD-ROM, a VCD, or a DVD. The optical disc drive  40  can be a CD-ROM drive, a VCD drive, or a DVD drive.  
         [0018]    The optical disc  50  comprises at least one session  56 , so if the optical disc  50  comprises a plurality of sessions, the plurality of sessions are arranged in outward order starting from the center of the optical disc  50 . Each session  56  comprises a lead-in area  58 , a program data area  60 , and a lead-out area  62 . The lead-in area  58  of the session  56  comprises a table of contents comprising the data of the amount of tracks, the beginning position of the tracks, and the length of the program data in the program area  60  of the session  56 . The optical disc drive  40  controls and moves the optical pickup  42  to a specific position of the optical disc  50  according to the data of the table of contents so as to read the data on the specific position. Because the lead-out area  62  of the session  56  is recorded with data of digital silence, the optical disc drive  40  can determine that the optical pickup  42  has read all the program data on the program area  60  of the session  56  when the optical pickup  42  has read the data of digital silence on the lead-out area  62 .  
         [0019]    The difference between the optical disc  50  of the present invention and the optical disc  20  of the prior art is that the lead-in area  58  of the optical disc  50  not only comprises the table of contents, but also comprises descriptive data  70  (which is shown in FIG. 3) used to describe the program data recorded on the program data area  60  of the optical disc  50 . In addition, the method of the present invention uses the rest of the memory space of the lead-in area  58  that is not recorded with the table of contents to record the descriptive data  70  so as to fully utilize the memory space of the lead-in area  58  of the optical disc  50 . For instance, if the table of contents occupies 5 M bytes of the memory space, the descriptive data  70  is recorded with the remaining 4 M bytes of the memory space. More specifically, the descriptive data  70  comprises a content data for describing the program data on the program data area  60 . For instance, if the program data recorded on the program data area  60  of the session  56  of the optical disc  50  is a song, the descriptive data recorded on the lead-in area  58  of the session  56  can be data of words of the song, composer of the song, or other information for describing the song.  
         [0020]    Please refer to FIG. 3. FIG. 3 is a diagram of the descriptive data  70  recorded in the lead-in area  58  of the session  56  of the optical disc  50  according to another embodiment of the present invention. The descriptive data  70  comprises four kinds of data including a category data  72 , a length data  74 , a content data  76 , and an ending data  78 , in order. The category data  72  is used for marking a category of the content data  76 , and the length data is used for marking a length of the content data  76 . Take the descriptive data  70  shown in FIG. 3 for example. The category data  72  is “01”, which represents that the content data  76  recorded on the lead-in area  58  are words of the program data that is assumed to be a song recorded on the program data area  60 . The length data  74  is “8000”, which represents that the length of the words of the song is 8000 bytes. The ending data  78  of the descriptive data  70  is used for marking an ending position of the descriptive data  70 . Thus, the optical disc drive  40  can determine that the optical pickup has read all the data of the descriptive data  70 , when the optical pickup  42  of the optical disc drive  40  has read the ending data  78  of the descriptive data  70  on the lead-in area  58  of the session  56  of the optical disc  50 .  
         [0021]    When the optical pickup  42  of the optical disc drive  40  has read all the data including the table of contents and the content data  70  on the lead-in area  58  of the session  56  of the optical disc  50 , it will continually read the program data on the program data area  60  of the session  56  of the optical disc  50 . When the optical pickup  42  of the optical disc drive  40  is used to read the program data and the optical disc drive  40  executes the program data, the optical disc drive  40  displays the content data  76 , which is read by the optical pickup  42  previously and describes the program data, on the monitor  44 .  
         [0022]    When the category data  72  is “00”, “10”, or “1”, this represents that the content data  76  recorded on the lead-in area  58  respectively is the title, author, or brief introduction of the song recorded on the program data  60 . And the length data  74  corresponding to the content data  76  respectively is the length of the title, author, or brief introduction of the song. Certainly, the descriptive data  70  also can comprise other sections according to the complexity of the content data  76 .  
         [0023]    To explain the method of the present invention more specifically, please refer to FIG. 4. FIG. 4 is a flow chart  100  of the method for accessing data on the optical disc  50  with the optical disc drive  40  according to the present invention. The flow chart  100  comprises following steps: Step  110 : Start. (At this time, the optical disc  50  has been put on the optical disc drive  40 .) Step  120 : Use the optical pickup  42  of the optical disc drive  40  to record a table of contents in a lead-in area of a session of the optical disc  50 .  
         [0024]    Step  130 :  
         [0025]    Use the optical pickup  42  to record descriptive data corresponding to the table of contents in the rest of the memory space of the lead-in area of the session.  
         [0026]    Step  140 :  
         [0027]    Use the optical pickup  42  to record program data corresponding to the table of contents in a program data area of the session.  
         [0028]    Step  150 :  
         [0029]    Use the optical pickup  42  to read the table of contents and the descriptive data in the lead-in area of the session.  
         [0030]    Step  160 :  
         [0031]    Use the optical pickup  42  to the program data in the program data area of the session according to the table of contents in the lead-in area of the session.  
         [0032]    Step  170 :  
         [0033]    Use the optical disc drive  40  to execute the program data and display the descriptive data on the monitor  44  at the same time.  
         [0034]    Step  180 :  
         [0035]    End. (While the optical disc drive  40  executes the program data, the monitor  44  of the optical disc drive  40  displays content data that describes the program data.)  
         [0036]    During step  170 , the optical disc drive  40  controls the monitor  44  to display the content data  76  of the descriptive data  70  on the monitor  44  according to the category data  72  of the descriptive data in the lead-in area  58  of the session  56 . For instance, when the category data  72  shows that the content data  76  is author of the song (the category data  72  is “10”), the optical disc drive  40  controls the monitor  44  to display the author with large letters until the song is finished playing, and when the category data  72  shows that the content data  76  are words of the song (the category data  72  is “01”), the optical disc drive  40  controls the monitor  44  to display the words with smaller letters as the song is executed and until the song is finished.  
         [0037]    As shown in FIG. 3, step  110  to step  140  are processes of using the optical pickup  42  of the optical disc drive  40  to record data to the optical disc  50 , and step  150  to step  180  are processes of using the optical pickup  42  of the optical disc drive  40  to read data on the program data area  60  of the lead-in area  58  of the optical disc  50 .  
         [0038]    Certainly, the optical disc drive  40  used in the present invention also can be used to access an ordinary optical disc, which comprises only a table of contents on the lead-in area of each session.  
         [0039]    In contrast to the method for accessing data on the optical disc with the optical disc drive according to the prior art, the present invention uses the rest of the memory space in the lead-in area  58  of the optical disc  50  for recording the descriptive data  70  describing the program data on the program data area  60  of the optical disc  50  so that the memory space of the lead-in area  58  can be fully utilized. Furthermore, the present invention also can display the descriptive data  70  on the monitor  44 , while using the optical drive  40  to execute the program data.  
         [0040]    Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.