Abstract:
An optical disk and an optical disk reproduction device for reproducing the same are provided. The optical disk including at least one layer comprises an information storage area for storing information on the optical disk and a data area for storing data, wherein the information storage area stores information on the amount of reflection and thickness of each of a plurality of layers, and transmission speed information on a plurality of areas which constitute the data area.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a National Stage of International Application No. PCT/KR2013/010052, filed on Nov. 7, 2013, which claims the priority of U.S. Provisional Application No. 61/723,497, filed Nov. 7, 2012 in the United States Patent Office, U.S. Provisional Application No. 61/815,408, filed on Apr. 24, 2013 in the United States Patent Office, and Korean Patent Application No. 10-2013-0133995, filed on Nov. 6, 2013 in the Korean Patent Office, the disclosures of all of which are incorporated herein by reference in their entireties. 
     
    
     BACKGROUND 
       [0002]    1. Field 
         [0003]    Apparatuses and methods consistent with exemplary embodiments relate to an optical disc and an optical disc reproduction apparatus for reproducing the same, and more particularly, to an optical disc which stores various information to be efficiently reproduced, and an optical disc reproduction apparatus for reproducing the same. 
         [0004]    2. Description of Related Art 
         [0005]    Generally, an optical disc reproduction apparatus reproduces data recorded on a disc such as compact disc (CD), compact disc-read only memory (CD-ROM), digital versatile disc (DVD), blu-ray disc (BD), CD-R, CD-RW, DVD±RW, or DVD-R. 
         [0006]    The trend is moving forward to higher definition image content, and optical discs need to be able to store high-capacity data in order to store high-definition images. One way to store high-capacity data on an optical disc is to record data on only one layer; however, recent optical discs have a plurality of layers, each generated to record data thereon. 
         [0007]    For an optical disc having a plurality of layers, more delicate and accurate techniques are necessary for inter-layer transition and for control or automatic adjustment of the respective layers. Particularly, optical discs having a high density of layers exhibit great differences in the servo signals on the respective layers at a stationery collimator lens (CL). Related technologies suffer the following shortcomings because they use an average value of several optical discs, and do not have specific information on the respective layers. 
         [0008]    First, during a pull-in operation, the lack of information on the respective layers causes a deterioration of the stability of the servo signals detected by the optical disc reproduction apparatus when the position of the CL is misaligned, and in some cases, the focus-on operation sometimes fails when the size of a focus error signal (or focus drive signal) is too big or too small. 
         [0009]    Further, during inter-layer transition, inter-layer transitions by way of layer jump are difficult in the beginning, even during stable operation on the current layer, due to a lack of information about the next layer. In the worst case, the inter-layer jump is ON on a layer different from n intended layer, or the layer jump itself fails. 
         [0010]    Further, even when the focus is ON on the intended layer, the position of the CL or gain value by the amount of reflection may not be correct, in which case the initial value for automatic adjustment is deviated from the actual optimum value, requiring more steps for the transition in the automatic adjustment. As a result, servo drop occurs, or time is delayed during automatic adjustment. An optical disc which is considerably different from an initial value for the automatic adjustment can even cause a disc misjudgment. 
         [0011]    Additionally, related art optical discs do not provide information about data transfer rate, or even if they do have information about data transfer rate, such information is limited to the overall basic transfer rate. Accordingly, an optical disc reproduction apparatus drives a driver at a spindle speed which corresponds to maximum velocity. If the apparatus fails to drive the driver at the spindle speed which is the maximum velocity supported, the transfer rate of the data read by the optical disc reproduction apparatus at a certain time point of increasing the transfer rate does not achieve the transfer rate as required by the optical disc. When this phenomenon continues for a predetermined time, a buffer underrun occurs. As a result, a data gap occurs for a predetermined time, which causes problems such as the image or sound being stopped. 
         [0012]    In order to deal with the problems mentioned above, related art solutions set the spindle speed to the maximum velocity. This means that the data transfer rate is faster than the transfer rate required by the optical disc, and accordingly, a phenomenon such as buffer underrun does not occur. However, as the driver has to be kept driving at the high-velocity spindle speed, noise and vibration are generated. Additionally, current consumption also greatly increases. 
       SUMMARY 
       [0013]    Accordingly, an object of one or more of the exemplary embodiments may be to provide an optical disc which stores information about amount of reflection and a thickness of each of a plurality of layers, and transfer rate information about each of a plurality of zones constituting a data zone, in order to drive the optical disc efficiently, and an optical disc reproduction apparatus for reproducing the same. 
         [0014]    According to an aspect of an exemplary embodiment, an optical disc is provided including a plurality of layers, which may include an information storage zone which stores information about the optical disc, and a data zone which stores data. The information storage zone may store reflection amount information and thickness information of each of the plurality of layers. 
         [0015]    The optical disc may be a blu-ray disc, and the information storage zone may be a permanent information control data (PIC) area included within a lead-in area of the optical disc. 
         [0016]    Further, the reflection amount and the thickness information of each of the plurality of layers may be stored in a reserved area of the PIC area. 
         [0017]    The reflection amount and the thickness information of each of the plurality of layers may be expressed as a value in the reserved area. 
         [0018]    The reflection amount and the thickness information of each of the plurality of layers may be expressed as one of a plurality of preset sections in the reserved area. 
         [0019]    According to an aspect of an exemplary embodiment, an optical disc reproduction apparatus is provided, which may include an optical pickup configured to emit light onto an information storage zone and to detect light reflected from the information storage zone, when an optical disc is mounted, the optical disc including the information storage zone storing therein reflection amount and thickness information of each of a plurality of layers, a signal processor configured to process the reflected light reflected from the information storage zone, and a controller configured to acquire the reflection amount and the thickness information of each of the plurality of layers of the optical disc based on a result of processing of the reflected light and to control reproduction of the optical disc. 
         [0020]    The optical pickup may additionally include a collimator lens, and the optical disc reproduction apparatus may additionally include an amplifier configured to amplifying the reflected light received from the optical pickup. The controller may control the position of the collimator lens based on the reflection amount and the thickness information, and control a gain of the amplifier to perform a focus-on operation that suits one of the plurality of layers. 
         [0021]    The controller may perform one of an automatic adjustment and a layer jump based on the reflection amount and the thickness information. 
         [0022]    According to an aspect of another exemplary embodiment, an optical disc including one or more layers is provided, which may include an information storage zone storing information about the optical disc, and a data zone divided into a plurality of areas and storing data. The information storage zone may store transfer rate information of each of the plurality of areas. 
         [0023]    The optical disc may be a blu-ray disc, and the information storage zone may be a permanent information control data (PIC) area included within a lead-in area of the optical disc. 
         [0024]    Further, the transfer rate information of each of the plurality of areas may be stored in a reserved area of the PIC area. 
         [0025]    Position information of a specific area and the transfer rate information of the specific area may be recorded in the reserved area sequentially. 
         [0026]    Position information of the plurality of areas may be recorded in the reserved area and then the transfer rate information of each of the plurality of areas may be recorded. 
         [0027]    The position information may be expressed as address information or radius information. 
         [0028]    According to an aspect of another exemplary embodiment, an optical disc reproduction apparatus is provided, which may include an optical pickup configured to emit light onto an information storage zone and to detect light reflected from the information storage zone, when an optical disc is mounted, the optical disc including the information storage zone storing therein transfer rate information of each of a plurality of areas constituting a data zone, a signal processor configured to process the reflected light reflected from the information storage zone, a driver configured to drive the optical disc, and a controller configured to acquire a transfer rate of each of the plurality of areas of the optical disc based on a result of processing of the reflected light and to control a spindle speed of the driver. 
         [0029]    The controller may acquire the position information of the currently-reproduced area during reproduction of the optical disc, compare the transfer rate corresponding to the currently-reproduced area with the spindle speed of the driver, and when the transfer rate corresponding to the currently-reproduced area is different from the spindle speed of the driver, the controller may control the driver to change the spindle speed of the driver to match the transfer rate corresponding to the currently-reproduced area. 
         [0030]    Further, when the address of the reproduced area is changed, the controller may compare the transfer rate of the area corresponding to the changed address with the spindle speed of the driver, and when the transfer rate of the area corresponding to the changed address is different from the spindle speed of the driver, the controller may control the driver to change the spindle speed of the driver to match the transfer rate of the area that corresponds to the changed address. 
         [0031]    According to an optical disc reproduction method according to one or more of the exemplary embodiments explained above, the optical disc reproduction apparatus may be capable of stably detecting a servo signal during focus pull-in operation, performing automatic adjustment within a shorter time, and performing a stable layer jump. 
         [0032]    Further, an optical disc reproduction apparatus according to one or more of the exemplary embodiments described above may be capable of preventing buffer underrun which is generated when the transfer rate requirement is not met, and also removing noise and vibration that may occur due to excessive spindle speed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0033]    The above and/or other exemplary aspects and advantages will become apparent and more readily appreciated from the following detailed description, taken in conjunction with the accompanying drawings in which: 
           [0034]      FIG. 1  is a diagram illustrating a focus error signal of a plurality of layers of a related art optical disc; 
           [0035]      FIG. 2  is a block diagram of an optical disc according to an exemplary embodiment; 
           [0036]      FIG. 3  is a diagram illustrating zones of a blu-ray disc according to an exemplary embodiment; 
           [0037]      FIG. 4  is a schematic block diagram of an optical disc reproduction apparatus according to an exemplary embodiment; 
           [0038]      FIG. 5  is a detailed block diagram of an optical disc reproduction apparatus according to an exemplary embodiment; 
           [0039]      FIG. 6  is a diagram illustrating a focus error signal of a plurality of layers of an optical disc according to an exemplary embodiment; and 
           [0040]      FIGS. 7 and 8  are flowcharts of an optical disc reproduction method according to an exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0041]    Exemplary embodiments will be explained in greater detail below with reference to the drawings.  FIG. 2  is a block diagram of an optical disc  100  according to an exemplary embodiment. Referring to  FIG. 2 , the optical disc  100  includes an information storage zone  110  and a data zone  120 . The optical disc  100  according to an embodiment may be a blu-ray disc (BD) having one or more layers, but is not limited thereto. Accordingly, the optical disc  100  may be any of a variety of optical discs such as a compact disc (CD), a digital versatile disc (DVD), a blu-ray ROM (BD-ROM) disc, etc. 
         [0042]    The information storage zone  110  stores information about the optical disc  100 . More specifically, the optical disc  100  may store information to enable an optical disc reproduction apparatus  200  to efficiently reproduce the optical disc. 
         [0043]    For example, the information storage zone  110  may store information about amounts of reflection and thicknesses of each of a plurality of layers of the optical disc  100 . More specifically, when the optical disc  100  is a blu-ray disc, the information storage zone  110  may be a permanent information control data (PIC) area which is included in a lead-in zone of the disc. The information about amounts of reflection and thicknesses of the respective layers may be stored in a reserved area of the PIC area. The information about the amounts of reflection and thicknesses of the plurality of layers may be expressed as specific values or as one or more preset sections in the reserved area. 
         [0044]    Alternately, for example, the information storage zone  100  may store information about transfer rates of each of the plurality of areas that constitute the data zone. Specifically, if the optical disc  100  is a blu-ray disc, the information storage zone  110  may be the permanent information control data (PIC) area included in the lead-in zone of the disc. The information about transfer rates of the respective layers constituting the data zone may be stored in the reserved area of the PIC area. The position information of a specific area and transfer rate information of a specific area may be stored sequentially in the reserved area, and the transfer rate information of the plurality of areas may be recorded after all the position information of the plurality of areas is recorded in the reserved area. The position information may be expressed as address information or radius information of each of the plurality of zones. 
         [0045]    The data zone  120  refers to a physical area that records data on the layer surfaces of the optical disc, and may refer to an any area other than the information storage zone explained above. 
         [0046]    As explained above, the information storage zone  110  may store the information about amounts of reflection and thicknesses of the layers, and information about the transfer rates of each of the plurality of areas that constitute the data zone so that the optical disc reproduction apparatus  200  can reproduce the optical disc having a plurality of layers with increased efficiency. 
         [0047]    Hereinbelow, an exemplary embodiment of storing various information on a blu-ray disc, in order to enable the blu-ray disc to be reproduced efficiently, will be explained with reference to  FIG. 3 . 
         [0048]    As illustrated in  FIG. 3 , the blu-ray disc includes an inner zone, a data zone  340 , and an outer zone. 
         [0049]    The inner zone may include a burst cutting area (BCA)  310  on which information such as copyright data media ID, etc. is recorded, and a lead-in zone  320 . According to the blu-ray ROM format standard, the BCA is radially located between about 21.0 mm-22.2 mm on the blu-ray disc. The lead-in zone  42  includes a permanent information control data (PIC) area on which information about the optical disc is recorded. According to the blu-ray ROM format standard, the PIC area may be radially located between about 22.5-23.2 mm on the blu-ray disc. 
         [0050]    Specifically, the related PIC area stores information about the blu-ray disc, as listed in Table 1 below. 
         [0000]    
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 Byte 
                   
                   
               
               
                 position in 
                   
                 Number 
               
               
                 Data Frame 0 
                 Content 
                 of Bytes 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                  0 
                 Disc Information identifier = “DI” 
                 2 
               
               
                  2 
                 DI Format number 
                 1 
               
               
                  3 
                 Number of DI units in each DI 
                 1 
               
               
                   
                 Block (5 bits) Number of the layer to 
               
               
                   
                 which this DI unit applies (3 bits) 
               
               
                  4 
                 Reserved = 00h 
                 1 
               
               
                  5 
                 DI unit sequence number in DI 
                 1 
               
               
                   
                 block (=0) 
               
               
                  6 
                 Continuation flag (1 bit) Number of DI 
                 1 
               
               
                   
                 bytes in use in this DI Unit (7 bits) 
               
               
                  7 
                 Reserved = 00h 
                 1 
               
               
                  8 to 10 
                 BD Layer Type identifier/Channel bit 
                 1 
               
               
                   
                 Length 
               
               
                 11 
                 Disc size/Class/Version 
                 1 
               
               
                 12 
                 BD structure 
                 1 
               
               
                 13 
                 Hybrid Disc identifier/Channel bit 
                 1 
               
               
                   
                 Length 
               
               
                 14 
                 Push-Pull polarity flag bits 
                 1 
               
               
                 15 
                 Reserved = 00h 
                 1 
               
               
                 16 
                 BCA descriptor 
                 1 
               
               
                 17 
                 maximum transfer rate of application 
                 1 
               
               
                 18 to 19 
                 Reserved = 00h 
                 1 
               
               
                 20 to 23 
                 Last User Data Address 
                 4 
               
               
                 24 to 31 
                 Data Zone allocation 
                 8 
               
               
                 32 to 60 
                 Reserved = 00h 
                 29 
               
               
                 61 and 62 
                 Time Stamp 
                 2 
               
               
                 63 
                 Reserved = 00h 
                 1 
               
               
                   
               
             
          
         
       
     
         [0051]    According to an exemplary embodiment, in order to store reflection amount and thickness information of each of the plurality of layers, the blu-ray disc may store reflection amount information of the plurality of layers in the reserved areas  32  to  46  of the PIC data, and store thickness information of the plurality of layers in the reserved areas  47  to  60 , as shown in Table 2 below. The reflection amount and thickness information may be expressed as specific values. 
         [0000]    
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                 Byte 
                   
                   
               
               
                 position in 
                   
                 Number 
               
               
                 Data Frame 0 
                 Content 
                 of Bytes 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                  0 
                 Disc Information identifier = “DI” 
                 2 
               
               
                  2 
                 DI Format number 
                 1 
               
               
                  3 
                 Number of DI units in each DI 
                 1 
               
               
                   
                 Block (5 bits) Number of the layer to 
               
               
                   
                 which this DI unit applies (3 bits) 
               
               
                  4 
                 Reserved = 00h 
                 1 
               
               
                  5 
                 DI unit sequence number in DI 
                 1 
               
               
                   
                 block (=0) 
                 1 
               
               
                  6 
                 Continuation flag (1 bit) Number of DI 
                 1 
               
               
                   
                 bytes in use in this DI Unit (7 bits) 
               
               
                  7 
                 Reserved = 00h 
                 1 
               
               
                  8 to 10 
                 BD Layer Type identifier/Channel bit 
                 1 
               
               
                   
                 Length 
               
               
                 11 
                 Disc size/Class/Version 
                 1 
               
               
                 12 
                 BD structure 
                 1 
               
               
                 13 
                 Hybrid Disc identifier/Channel bit 
                 1 
               
               
                   
                 Length 
               
               
                 14 
                 Push-Pull polarity flag bits 
                 1 
               
               
                 15 
                 Reserved = 00h 
                 1 
               
               
                 16 
                 BCA descriptor 
                 1 
               
               
                 17 
                 maximum transfer rate of application 
                 1 
               
               
                 18 to 19 
                 Reserved = 00h 
                 1 
               
               
                 20 to 23 
                 Last User Data Address 
                 4 
               
               
                 24 to 31 
                 Data Zone allocation 
                 8 
               
               
                 32 to 46 
                 Layer Reflection 
                 15 
               
               
                 47 and 60 
                 Layer Thickness 
                 14 
               
               
                 61 and 62 
                 Time Stamp 
                 2 
               
               
                 63 
                 Reserved = 00h 
                 1 
               
               
                   
               
             
          
         
       
     
         [0052]    According to another example of storing the reflection amount and thickness information of each of the plurality of layers, the blu-ray disc may store the reflection amount information of the plurality of layers and the thickness information of the plurality of layers sequentially in the reserved areas  32  to  60  of the PIC data, as shown in Table 3 below. The reflection amount and thickness information may be expressed as one of a number of preset sections. 
         [0000]    
       
         
               
               
               
             
           
               
                 TABLE 3 
               
               
                   
               
               
                 Byte 
                   
                   
               
               
                 position in 
                   
                 Number 
               
               
                 Data Frame 0 
                 Content 
                 of Bytes 
               
               
                   
               
             
             
               
                  0 
                 Disc Information identifier = “DI” 
                 2 
               
               
                  2 
                 DI Format number 
                 1 
               
               
                  3 
                 Number of DI units in each DI 
                 1 
               
               
                   
                 Block (5 bits) Number of the layer to 
               
               
                   
                 which this DI unit applies (3 bits) 
               
               
                  4 
                 Reserved = 00h 
                 1 
               
               
                  5 
                 DI unit sequence number in DI 
                 1 
               
               
                   
                 block (=0) 
               
               
                  6 
                 Continuation flag (1 bit) Number of DI 
                 1 
               
               
                   
                 bytes in use in this DI Unit (7 bits) 
               
               
                  7 
                 Reserved = 00h 
                 1 
               
               
                  8 to 10 
                 BD Layer Type identifier/Channel bit 
                 1 
               
               
                   
                 Length 
               
               
                 11 
                 Disc size/Class/Version 
                 1 
               
               
                 12 
                 BD structure 
                 1 
               
               
                 13 
                 Hybrid Disc identifier/Channel bit 
                 1 
               
               
                   
                 Length 
               
               
                 14 
                 Push-Pull polarity flag bits 
                 1 
               
               
                 15 
                 Reserved = 00h 
                 1 
               
               
                 16 
                 BCA descriptor 
                 1 
               
               
                 17 
                 maximum transfer rate of application 
                 1 
               
               
                 18 to 19 
                 Reserved = 00h 
                 1 
               
               
                 20 to 23 
                 Last User Data Address 
                 4 
               
               
                 24 to 31 
                 Data Zone allocation 
                 8 
               
               
                 32 
                 Layer 0 Reflection 
                 1 
               
               
                 33 
                 Layer 1 Reflection 
                 1 
               
               
                 34 
                 Layer 2 Reflection 
                 1 
               
               
                 . . . 
                 . . . 
               
               
                 47 
                 Layer 0 Thickness 
                 1 
               
               
                 48 
                 Layer 1 Thickness 
                 1 
               
               
                 49 
                 Layer 2 Thickness 
                 1 
               
               
                 . . . 
                 . . . 
               
               
                 61 and 62 
                 Time Stamp 
                 2 
               
               
                 63 
                 Reserved = 00h 
                 1 
               
               
                   
               
             
          
         
       
     
         [0053]    According to another exemplary embodiment, in order to store transfer rate information of each of the plurality of layers constituting the data zone, the blu-ray disc may store position information and transfer rate information of the plurality of layers sequentially in the reserved areas  32  to  60  of the PIC data. 
         [0000]    
       
         
               
               
               
             
           
               
                 TABLE 4 
               
               
                   
               
               
                 Byte 
                   
                   
               
               
                 position in 
                   
                 Number 
               
               
                 Data Frame 0 
                 Content 
                 of Bytes 
               
               
                   
               
             
             
               
                  0 
                 Disc Information identifier = “DI” 
                 2 
               
               
                  2 
                 DI Format number 
                 1 
               
               
                  3 
                 Number of DI units in each DI 
                 1 
               
               
                   
                 Block (5 bits) Number of the layer to 
               
               
                   
                 which this DI unit applies (3 bits) 
               
               
                  4 
                 Reserved = 00h 
                 1 
               
               
                  5 
                 DI unit sequence number in DI 
                 1 
               
               
                   
                 block (=0) 
               
               
                  6 
                 Continuation flag (1 bit) Number of DI 
                 1 
               
               
                   
                 bytes in use in this DI Unit (7 bits) 
               
               
                  7 
                 Reserved = 00h 
                 1 
               
               
                  8 to 10 
                 BD Layer Type identifier/Channel bit 
                 1 
               
               
                   
                 Length 
               
               
                 11 
                 Disc size/Class/Version 
                 1 
               
               
                 12 
                 BD structure 
                 1 
               
               
                 13 
                 Hybrid Disc identifier/Channel bit 
                 1 
               
               
                   
                 Length 
               
               
                 14 
                 Push-Pull polarity flag bits 
                 1 
               
               
                 15 
                 Reserved = 00h 
                 1 
               
               
                 16 
                 BCA descriptor 
                 1 
               
               
                 17 
                 maximum transfer rate of application 
                 1 
               
               
                 18 to 19 
                 Reserved = 00h 
                 1 
               
               
                 20 to 23 
                 Last User Data Address 
                 4 
               
               
                 24 to 31 
                 Data Zone allocation 
                 8 
               
               
                 32 
                 Zone 0 Position 
                 1 
               
               
                 33 
                 Zone 0 Transfer Rate 
                 1 
               
               
                 34 
                 Zone 1 Position 
                 1 
               
               
                 35 
                 Zone 1 Transfer Rate 
                 1 
               
               
                 . . . 
               
               
                 61 and 62 
                 Time Stamp 
                 2 
               
               
                 63 
                 Reserved = 00h 
                 1 
               
               
                   
               
             
          
         
       
     
         [0054]    According to another exemplary embodiment, as another method for storing transfer rate information of each of the plurality of layers constituting the data zone, the blu-ray disc may first store position information of the plurality of areas in the reserved areas  32  to  39  of the PIC data, and then store transfer rate information of the plurality of areas in the areas  40  to  60 , as shown in Table 5 below. 
         [0000]    
       
         
               
               
               
             
           
               
                 TABLE 5 
               
               
                   
               
               
                 Byte 
                   
                 Number 
               
               
                 position in 
                   
                 of 
               
               
                 Data Frame 0 
                 Content 
                 Bytes 
               
               
                   
               
             
             
               
                  0 
                 Disc Information identifier = “DI” 
                 2 
               
               
                  2 
                 DI Format number 
                 1 
               
               
                  3 
                 Number of DI units in each DI Block (5 
                 1 
               
               
                   
                 bits) Number of the layer to which 
               
               
                   
                 this DI unit applies (3 bits) 
               
               
                  4 
                 Reserved = 00h 
                 1 
               
               
                  5 
                 DI unit sequence number in DI 
                 1 
               
               
                   
                 block (=0) 
               
               
                  6 
                 Continuation flag (1 bit) Number of DI 
                 1 
               
               
                   
                 bytes in use in this DI Unit (7 bits) 
               
               
                  7 
                 Reserved = 00h 
                 1 
               
               
                  8 to 10 
                 BD Layer Type identifier/Channel bit 
                 1 
               
               
                   
                 Length 
               
               
                 11 
                 Disc size/Class/Version 
                 1 
               
               
                 12 
                 BD structure 
                 1 
               
               
                 13 
                 Hybrid Disc identifier/Channel bit 
                 1 
               
               
                   
                 Length 
               
               
                 14 
                 Push-Pull polarity flag bits 
                 1 
               
               
                 15 
                 Reserved = 00h 
                 1 
               
               
                 16 
                 BCA descriptor 
                 1 
               
               
                 17 
                 maximum transfer rate of application 
                 1 
               
               
                 18 to 19 
                 Reserved = 00h 
                 1 
               
               
                 20 to 23 
                 Last User Data Address 
                 4 
               
               
                 24 to 31 
                 Data Zone allocation 
                 8 
               
               
                 32 to 39 
                 Position Information (Transfer Rate) 
                 1 
               
               
                 33 
                 Zone 0 Transfer Rate 
                 1 
               
               
                 34 
                 Zone 1 Transfer Rate 
                 1 
               
               
                 35 
                 Zone 2 Transfer Rate 
                 1 
               
               
                 . . . 
               
               
                 61 and 62 
                 Time Stamp 
                 2 
               
               
                 63 
                 Reserved = 00h 
                 1 
               
               
                   
               
             
          
         
       
     
         [0055]    As explained above with reference to Tables 2 through 5, the blu-ray disc may store reflection amount information and thickness information of a plurality of layers, and transfer rate information of a plurality of areas of the data zone, in the information storage zone (i.e., the PIC area). 
         [0056]    The outer zone includes a lead-out zone  430 , and the data zone  440  exists between the lead-in zone  420  and the lead-out zone  430 . 
         [0057]    In conjunction with the blu-ray disc explained above, the optical disc reproduction apparatus  200  is able to reproduce a blu-ray disc more efficiently, using the reflection amount information and thickness information of the plurality of layers stored in the PIC area of the blu-ray disc, and the transfer rate information of the plurality of areas of the data zone. 
         [0058]    Hereinbelow, an optical disc reproduction apparatus  200  according to an embodiment will be explained with reference to  FIGS. 4 to 6 . 
         [0059]      FIG. 4  is a schematic block diagram of the optical disc reproduction apparatus  200  according to an exemplary embodiment. Referring to  FIG. 4 , the optical disc reproduction apparatus  200  includes an optical pickup  210 , a signal processor  220  and a controller  230 . The optical disc reproduction apparatus  200  may be a BD player, but not limited thereto. Accordingly, the optical disc reproduction apparatus  200  may be any of a variety of optical disc reproduction apparatuses  200  such as a CD player, a DVD player, etc. 
         [0060]    The optical pickup  210  reads data recorded on the optical disc. That is, the optical pickup  210  reads the data recorded on the optical disc by emitting light onto the surface of the optical disc and detecting the light reflected from the surface of the optical disc. Additionally, the optical pickup  210  may perform the function of recording data on the optical disc  100 . The optical pickup  210  may include a collimator lens through which light is emitted onto the surface of the optical disc. 
         [0061]    According to an exemplary embodiment, when an optical disc  100  is mounted, the optical disc  100  including the information storage zone storing therein reflection amount information and thickness information of each of the plurality of layers, the optical pickup  210  may emit light onto the information storage zone of the optical disc  100  and detect the reflected light from the information storage zone. 
         [0062]    According to another exemplary embodiment, when the optical disc  100  is mounted, the optical disc  100  including the information storage zone that stores transfer rate information of each of the plurality of areas constituting the data zone, the optical pickup  210  may emit light onto the information storage zone and detect the reflected light from the information storage zone. 
         [0063]    The signal processor  220  may acquire a radio frequency (RF) signal or a servo control signal by signal-processing the detected reflected light. Specifically, the signal processor  220  generates a servo control signal to perform mechanical servo control to thus pickup the RF signal accurately from the data zone  120  of the optical disc. 
         [0064]    The controller  230  controls the overall operation of the optical disc reproduction apparatus  200 . 
         [0065]    According to an exemplary embodiment, when the optical disc is mounted, the optical disc including the information storage zone storing therein reflection amount information and thickness information of each of the plurality of layers, the controller  230  may acquire the reflection amount information and thickness information of each of the plurality of layers of the optical disc based on the result of processing of the reflected light carried out at the signal processor  220 . 
         [0066]    That is, the controller may perform a focus-on operation that suits one of a plurality of layers, by adjusting a position of the collimator lens of the optical pickup  210  or by controlling a gain value of the servo control signal based on the acquired reflection amount information and thickness information. 
         [0067]    Further, the controller  230  may perform automatic adjustment of the gain values and the position of the collimator lens which are calculated based on the acquired reflection amount information and thickness information. Specifically, because there is no substantial difference between the optimum point for the automatic adjustment and a reference point that is calculated based on the acquired reflection amount information and thickness information, even a short distance of movement may be enough to perform an automatic adjustment. Therefore, adjustment time can be shortened. That is, in the related art in which information about characteristics of the layers of the optical disc are not known, the automatic adjustment is performed based on the same reference point for all the optical discs. Accordingly, when the reference point is deviated to a certain side, the automatic adjustment would have monotone decrease/monotone increase in the curve fitting result. As a result, the time for the automatic adjustment increases or the automatic adjustment fails according to the related art. According to one or more exemplary embodiments described herein, the reference point for the automatic adjustment is calculated based on the reflection amount information and thickness information of the layers. Accordingly, the difference between the optimum point and the reference point is decreased, thus allowing acquisition of accurate curve fitting result with a small movement, which can lead into stable automatic adjustment. 
         [0068]    Further, the controller  130  may perform a layer jump based on the reflection amount information and thickness information. That is, in response to a user command for a layer jump or to perform a layer jump during a lead-in operation, the controller  130  may adjust the position of the collimator lens based on the reflection amount information and thickness information and adjust the gain value of the servo control signal, to ensure that a stable layer jump is performed. Accordingly, the time required for the layer jump is shortened, and the possibility that the layer jump may fail, decreases. 
         [0069]    Specifically, according to an exemplary embodiment, when the optical disc is mounted, the optical disc including the information storage zone storing therein reflection amount information and thickness information of each of the plurality of layers, the controller  230  may acquire the reflection amount information and thickness information of each of the plurality of layers of the optical disc based on the result of processing the reflected light carried out at the signal processor  220  and control the reproduction of the optical disc. 
         [0070]    Meanwhile, according to an exemplary embodiment, when the optical disc is mounted, the optical disc including the information storage zone that stores transfer rate information of each of the plurality of areas constituting the data zone, the controller  230  may acquire the transfer rate information of each of the plurality of areas of the optical disc based on the result of processing of the reflected light carried out at the signal processor  220  and control the spindle speed of the driver. 
         [0071]    That is, the controller  230  acquires the position information of the currently-reproduced area based on the result of processing the reflected light, and compares the transfer rate corresponding to the currently-reproduced area with the spindle speed of the driver. When the transfer rate corresponding to the currently-reproduced area is same as the spindle speed of the driver, the controller  230  maintains the spindle speed of the driver. However, when the transfer rate corresponding to the currently-reproduced area is different from the spindle speed of the driver, the controller  230  may change the spindle speed of the driver to match the transfer rate corresponding to the currently-reproduced area. 
         [0072]    Further, when the address of the reproduced area is changed during optical disc reproduction, the controller  230  compares the transfer rate of the area corresponding to the changed address with the spindle speed of the driver. When the transfer rate of the area corresponding to the changed address is same as the spindle speed of the driver, the controller  230  maintains the spindle speed of the driver. However, when the transfer rate of the area corresponding to the changed address is different from the spindle speed of the driver, the controller  230  may change the spindle speed of the driver to match the transfer rate of the area that corresponds to the changed address. 
         [0073]    As explained above, by checking the transfer rate information of the plurality of areas, the optical disc reproduction apparatus  200  is able to reproduce the optical disc at an optimum spindle speed. As a result, the stopping of images, and noise and vibration can be eliminated. 
         [0074]      FIG. 5  is a detailed block diagram of the optical disc reproduction apparatus  200  according to an exemplary embodiment. Referring to  FIG. 5 , the optical disc reproduction apparatus  200  includes an optical pickup  210 , an amplifier  240 , a signal processor  220 , a driver  250  and a controller  230 . 
         [0075]    The optical pickup  210 , under control of the controller  230 , emits light onto the optical disc  100  and detects reflected light. Specifically, the optical pickup  210  is driven by a tracking actuator for tracking servo control and a focusing actuator for focus servo control, and is configured to optically pickup the data recorded on the optical disc  100  and convert it into electric RF signals. 
         [0076]    The optical pickup  210  includes a collimator lens through which light is emitted onto the optical disc  100  and may perform a focus-on operation and a layer jump by adjusting the position of the collimator lens. 
         [0077]    The amplifier  210  amplifies a signal received from the optical pickup  210 . Specifically, the amplifier  210  includes a built-in a focus error detection circuit and a tracking error detection circuit to generate a focus error signal and a tracking error signal from the amplified RF signal. 
         [0078]    The signal processor  220  processes the amplified signal from the amplifier  210 . Specifically, the signal processor  220  may offset gain and phase with regard to the focus error signal and the tracking error signal generated from the amplifier  210  and output a focus drive signal and a tracking drive signal. 
         [0079]    The driver  250  drives a disc motor, or the focusing actuator and the tracking actuator in the optical pickup  110  according to control of the controller  230 . 
         [0080]    The controller  250  controls the overall operation of the optical disc reproduction apparatus  200 . Specifically, when the optical disc storing the reproduction information about the optical disc is mounted, the controller  230  may control the reproduction of the optical disc based on the reproduction information about the optical disc. 
         [0081]    According to an exemplary embodiment, when the optical disc is mounted, the optical disc including the information storage zone storing therein reflection amount information and thickness information of each of the plurality of layers, the controller  230  may acquire the reflection amount information and thickness information of each of the plurality of layers of the optical disc using the optical pickup  210  and the signal processor  220 . The controller  230  may then adjust the gain value of the amplifier  240 , or adjust the position of the collimator lens of the optical pickup  210  based on the acquired reflection amount information and thickness information, to perform focus-on operation of the optical disc, automatic adjustment and layer transition (or layer jump), etc., as explained above. 
         [0082]    Specifically, the controller  230  may detect a focus error signal having a suitable size for each of the layers, as illustrated in  FIG. 6 , by adjusting the gain value of the amplifier  240  or adjusting position of the collimator lens of the optical pickup  210  based on the based on the reflection amount information and thickness information of each of the plurality of layers. 
         [0083]    The controller  230  may perform a focus-on, an automatic adjustment, or an inter-layer transition of the optical disc  100  based on the detected focus error signal, or the like. 
         [0084]    According to another exemplary embodiment, when the optical disc is mounted, the optical disc including the information storage zone that stores transfer rate information of each of the plurality of areas constituting the data zone  120 , the controller  230  may acquire the transfer rate information of each of the plurality of areas of the optical disc, using the optical pickup  210  and the signal processor  220 . The controller  230  may then control the spindle speed of the driver  250  based on the acquired transfer rate information of each of the plurality of areas. 
         [0085]    That is, the controller  230  checks the position information of a currently-reproduced area. The controller  230  then compares the transfer rate corresponding to the currently-reproduced area with the spindle speed of the driver  250 . When the transfer rate corresponding to the currently-reproduced area is different from the spindle speed of the driver, the controller  230  may change the spindle speed of the driver to match the transfer rate corresponding to the currently-reproduced area. 
         [0086]    Furthermore, when the address of the reproduced area is changed, the controller  230  may compare the transfer rate of the area corresponding to the changed address with the spindle speed of the driver  250 . When the transfer rate of the area corresponding to the changed address is different from the spindle speed of the driver  250 , the controller  230  may change the spindle speed of the driver  250  to match the transfer rate of the area that corresponds to the changed address. 
         [0087]    Hereinbelow, an optical disc reproduction method of the optical disc reproduction apparatus  200  according to an exemplary embodiment will be explained with reference to  FIGS. 7 and 8 . 
         [0088]      FIG. 7  is a flowchart provided to explain an optical disc reproduction method according to an exemplary embodiment, in an example in which an optical disc is mounted, the optical disc storing therein reflection amount information and thickness information of each of a plurality of layers. 
         [0089]    At S 710 , the optical disc reproduction apparatus  200  determines whether or not the optical disc  100  is mounted. The information storage zone  110  of the optical disc  100  may store reflection amount information and thickness information of each of a plurality of layers. 
         [0090]    At S 710 -Y, when the optical disc  100  is mounted, the optical disc reproduction apparatus  200  emits light onto the information storage zone and detects reflected light, at S 720 . The optical disc reproduction apparatus  200  processes the reflected light, at S 730 , and acquires reflection amount information and thickness information of each of a plurality of layers of the optical disc  100  from the processed reflected light, at S 740 . 
         [0091]    The optical disc reproduction apparatus  200  controls the reproduction of the optical disc based on the acquired reflection amount information and thickness information, at S 750 . Specifically, based on the acquired reflection amount information and thickness information, the optical disc reproduction apparatus  200  may adjust the gain value of the amplifier  240 , or adjust the position of the collimator lens of the optical pickup  210 , to thus perform a focus-on operation, an automatic adjustment, a layer jump), etc. 
         [0092]    With the optical disc reproduction method explained above, an exemplary optical disc reproduction apparatus is capable of stably detecting a servo signal during focus pull-in operation, performing an automatic adjustment within shorter time, and performing a stable layer jump. 
         [0093]      FIG. 8  is a flowchart provided to explain an optical disc reproduction method according to an exemplary embodiment, in an example in which the optical disc is mounted, the optical disc storing transfer rate information about each of a plurality of areas constituting the data zone. 
         [0094]    The optical disc reproduction apparatus  200  determines whether or not the optical disc  100  is mounted, at S 810 . The information storage zone  110  of the optical disc  100  may store transfer rate information of each of a plurality of areas constituting the data zone. 
         [0095]    At D 810 -Y, when the optical disc  100  is mounted, the optical disc reproduction apparatus  200  emits light onto the information storage zone and detects reflected light, at S 820 . The optical disc reproduction apparatus  200  processes the reflected light, at S 830 , and acquires transfer rate information of each of a plurality of areas constituting the data zone from the processed reflected light, at S 840 . 
         [0096]    The optical disc reproduction apparatus  200  controls the spindle speed of the driver  250  based on the transfer rate information of each of the plurality of areas, at S 850 . Specifically, the optical disc reproduction apparatus  200  may acquire the position information of the currently-reproduced area based on the result of processing of the reflected light, and compare the transfer rate corresponding to the currently-reproduced area with the spindle speed of the driver  250 . When the transfer rate corresponding to the currently-reproduced area is different from the spindle speed of the driver, the optical disc reproduction apparatus  200  may change the spindle speed of the driver to match the transfer rate corresponding to the currently-reproduced area. 
         [0097]    According to the optical disc reproduction method as explained above, the optical disc reproduction apparatus  200  is capable of preventing buffer underrun which is generated when the transfer rate requirement is not met, and also removing noise and vibration that may occur due to excessive spindle speed. 
         [0098]    The foregoing exemplary embodiments and advantages are merely exemplary and are not to be construed as limiting. The present teaching can be readily applied to other types of apparatuses. Also, the description of exemplary embodiments is intended to be illustrative, and not to limit the scope of the claims, and many alternatives, modifications, and variations will be apparent to those skilled in the art.