Abstract:
An optical recording medium having a track on which data has been previously recorded, comprising on the track a plurality of data block regions each of which includes main data of a block which is divided into a predetermined number of main data pieces, each of which has data for identifying the main data, and linking regions each of which has pseudo data and is inserted between the data block regions. When the linking regions on said track are adjacent, recording patterns of the pseudo data of the adjacent linking regions are different from each other. Further provided is a recording apparatus forming the data block regions and linking regions on a recording medium.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to an optical recording medium and to a recording apparatus for forming the recording medium. 
         [0003]    2. Description of the Related Art 
         [0004]    On a recordable optical recording medium such as DVD-R and DVD-RW, when new information data is written behind a location that has already, been written, a linking region is formed at that junction portion. Synchronization data for reading the information data written into a data region, which follows the linking region, is written into the linking region. 
         [0005]    However, the fact that linking regions are formed on such a recordable recording medium leads to a problem that there is a possibility of incompatibility in the recording format with read-only recording media such as DVD-ROMs that are not recordable. 
       SUMMARY OF THE INVENTION 
       [0006]    It is an object of the present invention to provide a read-only optical recording medium that is compatible with recordable optical recording media in the recording format and, apparatus and method for forming, the read-only optical recording medium. 
         [0007]    An optical recording medium having recorded data on a track thereof, according to the present invention, comprises on the track: a plurality of data block regions each of which includes main data of a block which serves as an error correction unit for the main data and which is divided into a predetermined number of main data pieces, each of which has data for identifying the main data; and linking regions each of which has pseudo data and is inserted between the plurality of data block regions; wherein when the linking regions on the track are adjacent, recording patterns of the pseudo data of the adjacent linking regions are different from each other. 
         [0008]    A recording apparatus for recording data onto a track of an optical recording medium, according to the present invention, comprises: a main, data recording device which forms on the track a plurality of data block regions each of which includes main data of a block which serves as an error correction unit for the main data and which is divided into a predetermined number of main data pieces, each of which has data for identifying the main data; and a linking data recording device which inserts linking regions each of which has pseudo data between the plurality of data block regions onto the track; wherein the linking data, recording means, when, the linking regions on the track are adjacent, forms the pseudo data of the adjacent linking regions with recording patterns which are different, from each other. 
         [0009]    A recording method for recording data onto a track of an optical recording medium, according to the present invention, comprises the steps of: forming on the track a plurality of data block regions each of which includes main data of a block which serves as an error correction unit for the main data and which is divided into a predetermined number of main data pieces, each of which has data for identifying the main data; and inserting linking regions each of which has pseudo data between the plurality of data block regions onto the track; wherein when the linking regions on the track are adjacent, the pseudo data of the adjacent linking regions is formed with recording patterns which are different from each other. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a block diagram showing the configuration of a recording apparatus according to the present invention. 
           [0011]      FIG. 2  is a block diagram illustrating the configuration of a random value generator in: the apparatus in  FIG. 1 . 
           [0012]      FIG. 3  is a diagram showing the data structure of one ECC block. 
           [0013]      FIG. 4  is a diagram showing the data structure of the recording signal for one sector. 
           [0014]      FIG. 5  is a diagram showing a linking region between ECC blocks. 
           [0015]      FIG. 6  is a diagram showing the position of each linking region on a track. 
           [0016]      FIG. 7  is a diagram showing linking regions closely positioned between adjacent track portions. 
           [0017]      FIG. 8  is a diagram showing a linking region including address data that is arranged between ECC blocks. 
           [0018]      FIG. 9  is a block diagram of the configuration of a recording apparatus as another embodiment of the present invention. 
           [0019]      FIG. 10  is a block diagram of the configuration of a recording apparatus as another embodiment of the present invention. 
           [0020]      FIG. 11  is a block diagram of the configuration of a recording apparatus as another embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    The present invention will be described below in more detail with reference to the accompanying drawings in accordance with the embodiments. 
         [0022]      FIG. 1  shows an original disk recording apparatus according to the present invention. The recording apparatus records information onto an original recording disk  1  for DVD-ROMs, and includes a master clock generator  11 , a PLL circuit  12 , a recording signal generation circuit  13 , an optical modulator  14 , a recording actuator  15 , a spindle motor  16 , a servo controller  17 , and a main controller  18 . 
         [0023]    The master clock generator  11  generates a master clock signal, and supplies the master clock signal to the PLL circuit  12  and the servo controller  17 . The servo controller  17  is supplied with the master clock signal, and with a frequency signal FG indicating a rotation frequency from, the spindle motor  16 . The servo controller  17  carries out rotation control for the spindle motor  16  such that the frequency signal FG is synchronized with the master clock signal, that is, it carries out spindle servo control. 
         [0024]    The PLL circuit  12  generates a recording clock signal based on the master clock signal. The recording signal generation circuit  13  includes a data generation portion  20 , an ECC block generation circuit  21 , a random value generator  22 , a timing circuit  23 , a switching circuit  24 , a modulator  25 , and a synchronization adding circuit  26 . The data generation portion  20  outputs information data (main data) to be recorded and address data corresponding to the information data. The ECC block generation circuit  21  outputs sector data adopted to ECC (error correction code) blocks, based on the information data and the address data. The random value generator  22  generates random data for linking regions. The timing circuit  23  generates a timing signal for each ECC block in response to the recording clock signal. The switching circuit  24  selectively outputs one of information data in the ECC block and the random data in accordance with the timing signal. The modulator  25  performs 8-16 modulation for data output from the switching circuit  24 . The synchronization adding circuit  26  adds a synchronization code, having a 14T synchronization pattern to the modulated data so as to output a recording signal. The main controller  18  controls the components  20  to  26  inside the recording signal generation circuit  13  in synchronization with the output clock of the PLL circuit  12 . 
         [0025]    The optical modulator  14  modulates laser light in accordance with the recording signal output from the recording signal generation circuit  13 , and supplies the modulated laser light to a recording actuator  15 . The recording actuator  15  irradiates the laser light onto the recording portion of the original recording disk  1  rotated by the spindle motor  16 , thus carrying out exposure. 
         [0026]    As shown in  FIG. 2 , the random value generator  22  includes a memory  31 , eleven D flip-flop circuits  32  to  42 , and one adder  44 . An initial value of eleven bits is previously stored in the memory  31 , and each one bit is supplied to the D flip-flops circuits  32  to  42  in response to a command from the main controller  18  at the beginning of recording of the original recording disk  1 . Each of the D flip-flops, circuits  32  to  42  has a preset input, and the bits corresponding to the initial value is respectively supplied to those preset inputs from the memory  31 . In response to the clock, each of the D flip-flops circuits  32  to  42  outputs from the output Q one bit of data supplied to the input D. The D flip-flops circuits  32  to  42  are connected in the form of a ring via the adder  44 . That is to say, the adder  44  is connected between the flip-flop circuits  32  and  33 , and the output Q of the flip-flop circuit  42  is connected to the adder  44  and to the input D of the flip-flop circuit  32 . The adder  44  adds data of the output Q of the flip-flop circuit  32  and data of the output Q of the flip-flop circuit  42 , and supplies a result of the addition to the input D of the flip-flop circuit  33 . Data having eight bits for the linking region is output from the outputs Q of the D flip-flop circuits  35  to  42 . The linking region data is pseudo data of an information data piece. 
         [0027]    The following is an explanation of the operation of the original disk recording apparatus according, to the present invention. 
         [0028]    Based on information data and address data to be recorded, the ECC block generation circuit  21  successively produces and outputs a data pieces of 91 bytes. 
         [0029]    In the DVD format, one ECC block has sixteen sectors, as shown in  FIG. 3 . Each sector has a data structure of 13 rows×1.82 bytes. 91 bytes of each row constitute one data piece, so that each row has two data pieces (91 bytes×2). 
         [0030]    The data pieces are supplied via the switching circuit  24  to the modulator  25 . After having, been subjected to 8-16 modulation, the data pieces are supplied to the synchronization adding circuit  26 . The synchronization adding circuit  26  adds a synchronization code (32 bits) including a 14T synchronization pattern to the data pieces having 182 bytes (1456 bits) that have been modulated, to generate a recording signal. The synchronization code is one of eight codes SY 0  to SY 7 , and serves as identification data for identifying data position in each sector. 
         [0031]      FIG. 4  illustrates the data structure of the recording signal for one sector. The synchronization code (SY 0  to SY 7 ) is located before the modulated data pieces, and two pairs of synchronization code and data piece are arranged in each row. 
         [0032]    On the other hand, at the time of the beginning of the recording, the initial value is output from the memory  31  to the eleven D flip-flop circuits  32  to  42  in the random value generator  22 . Each of the D flip-flop circuits  32  to  42  outputs a corresponding bit value of the initial value. The output values of the D flip-flop circuits  35  to  42  then serve as the linking region data. After that, whenever a clock signal is supplied, each of the D flip-flop circuits  32  to  42  read the output value of each of the D flip-flop circuits, or the adder  44  connected to each input side, and the D flip-flop circuits  35  to  42  output as eight bits (one byte) of linking region data. As the clock is supplied to the clock terminals C of the D flip-flops  32  to  42  for every linking region, for example, the linking region data is renewed at each clock by an adding operation of the adder  44 . The linking region data is pseudo data of the above-described data pieces, and consists of 91 bytes. For one linking region, linking region data of 91×2 bytes is generated. 
         [0033]    The switching circuit  24  performs a switching operation in response to the timing, signal after relaying the data pieces for one ECC block portion from the ECC block generation circuit  21 . Thus, the switching circuit  24  becomes a state in which the output data from the random value generator  22  is relayed to the modulator  25 . The linking region data is supplied from the random value generator  22  via the switching circuit  24  to the modulator  25 . After being subjected to 8-16 modulation, the linking region data is supplied to the synchronization adding circuit  26 . The synchronization adding circuit  26  adds a linking region synchronization code (32 bits) including a 14T synchronization pattern to the linking region data of 182 bytes (1456 bits) that have been modulated, to generate a recording signal. The first synchronization code of one row is SYX, and the second synchronization code is SYY. Each of the synchronization codes SYX and SYY has a pattern that is different from the synchronization codes SY 0  to SY 7 , and represents a linking region. 
         [0034]    The linking region is formed between ECC blocks (data block regions), and as shown in  FIG. 5 , includes two synchronization frames that are arranged between one ECC block (n−1) and the next ECC block (n). 
         [0035]    The recording signal output from the recording signal generation circuit  13  modulates laser light in the optical modulator  14 , and after the modulation, the laser light is supplied to the recording actuator  15 . The recording actuator  15  irradiates the laser light onto the recording portion of the original recording disk  1 , which is rotated by the spindle motor  16 , and thus exposure is performed. 
         [0036]    After producing a master disk from the original recording disk  1 , optical disks are obtained by duplication with a stamper of the master disk. 
         [0037]    Linking regions are formed on each track portion of the optical disk, as shown in  FIG. 6  for example. Furthermore, between any adjacent track portions, the linking regions may be formed adjacently to one another, as shown in  FIG. 7 . However, since the random value generated from the random value, generator  22  is used for the linking region data as described above, the data patterns of the linking region of the adjacent track portions are different from one another. For example, in the data patterns of adjacent linking regions shown in  FIG. 7 , the first pattern, the second pattern and the third pattern are mutually different. 
         [0038]    In order to accurately read the information recorded on the optical disk, a tracking control for controlling a reading light beam on a recording track is performed. The phase-difference method can be used as the tracking control for high-density optical disks such as DVD-ROMs. In the phase-difference method, a tracking error signal is generated, which indicates the error between the irradiation position of the light beam and the recording track, in accordance with the difference between the sum signals of the light-receiving signals of opposite light-receiving portions in a photo-detector partitioned into four, partitions. In the case of the phase-difference method, when the correlation between adjacent track portions is strong, then the tracking error signal includes cross-talk components from the adjacent track portions, so that the tracking control becomes instable. If there are adjacent, linking regions in adjacent track portions, the data pattern of those linking regions are different from one another, so that the correlation of the adjacent track portions can be reduced. Thus, it is possible to attain a stable tracking control even when using the phase-difference method for the tracking control. 
         [0039]    It is possible that the random value generator  22  uses current address data (which indicates an address of the adjacent data region) as the initial value. That is to say, as indicated by a dashed line in  FIG. 1 , address data may be supplied to the random value generator  22 , and the address data may be input from the preset input into the D flip-flop circuits  32  to  42  when the first linking region has been reached, to generate the linking region, data. Furthermore, it is also possible to prepare a plurality of initial values in the memory  31 , and to select one of the plurality of initial values in accordance with the address data. 
         [0040]    If the address data is used as the initial value, then the address data may also be recorded together with the random linking region data in the random value generator  22 . For example, as shown in  FIG. 8 , the synchronization codes SYX and SYY, the address data and the linking region data are arranged in that order in the two synchronization frames of the linking region. If, the random value generation pattern of the random value generator  22  corresponding to the initial value is previously known, then it is possible to read out the address data and the linking region data, and to use the linking region data as useful data, based on the relation between the address data and the linking region data. 
         [0041]    Moreover, as shown in  FIG. 9 , it is also possible to connect the random value generator  22  in series with a random value generator  28  having the same configuration as the generator  22 . 
         [0042]    Furthermore, as a configuration for generating linking region data, it is also possible to use a random value generator  22 , a scrambling circuit  29  and a memory  30 , as shown in  FIG. 10 . The scrambling circuit  29  consists of an EX-OR circuit. Scrambling data of eight bits is previously written into the memory  30 . In the scrambling circuit  29 , the EX-OR value of the scrambling data and the linking region data generated by the random value generator  22  for each linking region is obtained, and that value is used as the final linking region data. 
         [0043]      FIG. 10  shows another configuration example of a recording signal generation circuit  13 . In the linking region data generation portion in  FIG. 10 , it is possible to connect the random value generator  22  in series with a random value generator  28 , as in the configuration shown in  FIG. 9 . Furthermore, it is also possible to supply the address data to the random value generator  22 , as indicated by a dashed line in  FIG. 10 , and to use the address data at the time of the beginning of recording as the initial value. 
         [0044]      FIG. 11  shows another configuration example of a recording signal generation circuit  13 . In the recording signal generation circuit  13  in  FIG. 11 , the ECC block generation circuit  21 , the modulator  25 , the synchronization adding circuit  26  and the switching circuit  24  are connected in that order, and the switching circuit  24  is provided in the stage following the synchronization adding circuit  26 . The random value generator  22  and a modulator  22   a  are provided as a configuration for generating linking region data. After the linking region data output from the random value generator  22  have been subjected to 8-16 modulation by the modulator  22   a , the data is supplied to the switching circuit  24 . In accordance with the timing signal output from the timing circuit  23 , the switching circuit  24  selectively supplies either the output data of the synchronization adding circuit  26  or the output data of the modulator  22   a  to the optical modulator  14 . Thus, no synchronization code is added to the linking region data, so that the linking region formed between the ECC blocks on the track of the disk  1  has only linking region data that is pseudo data not including the synchronization code. 
         [0045]    In the recording apparatus as described above, linking data recording means forms the pseudo data of the adjacent linking regions with recording patterns which are different from each other. In the optical recording medium, the recording patterns of pseudo data of linking regions that are located on adjacent track portions of a track are different from one another. Thus, it is possible to provide read-only non-recordable optical recording media such as DVD-ROMs and recordable optical recording media such as DVD-RWs, with compatibility regarding the recording format. As a result, recording medium players can be designed with a simple configuration. This application is based on Japanese Patent Applications No. 2002-234476 and No. 2003-019159 which are hereby incorporated by reference.