Patent Publication Number: US-2004042370-A1

Title: Recording method, reproducing apparatus, recording medium

Description:
BACKGROUND OF THE INVENTION  
       [0001] The present invention relates to a technique for recording data onto a recording medium, more particularly, to a technique for recording data and management information which manages the data onto a recording medium.  
       [0002] When data is recorded as a file onto a recording medium, the data and management information which manages the data need to be recorded onto a recording medium.  
       [0003] For example, JP-A no.23312/2001 discloses a technique for separating clearly between a data recording area and a management information recording area, for previously determining an amount of the management information recording area, for recording the management information from the inside of a recording medium, and for recording the data from the outside of the recording medium.  
       SUMMARY OF THE INVENTION  
       [0004] When such a technique was executed in a recording apparatus, problems described below were not taken into account.  
       [0005] First, when the management information area was previously determined on a non-rewritable recording medium, the recording area could not be efficiently used. This is because an amount of the management information area changes widely according to the number of files to be recorded and to a frequency of additional recording so that an optimum amount of the area cannot be determined. For example, if the management information area comes short before the data recording area is fully used, data cannot be recorded onto the data recording area still having a recordable space. On the other hand, if the data recording area is fully used, the management information cannot be recorded onto the management information area still having a recordable space, which is thus wasted.  
       [0006] Second, when a data recording area is provided on the outside of a recording medium, and when data is recorded outward from a position separated inward by an amount of the data, the amount needs to be previously determined. However, the amount cannot be always previously determined. For example, when a video recorder records image/sound data, an amount of the image/sound data changes widely according to a recording rate and recording time of the data. The prior technique could not be applicable to such a case.  
       [0007] An object of the present invention is to solve the problems of the prior technique. Another object of the present invention is to provide a recording technique for efficiently using a recording area on a recording medium.  
       [0008] To achieve the above-described objects, the present invention provides a technique for recording data and management information which manages the data onto a recording medium. In this method, the data is recorded from a position separated inward from other data already recorded on a data recording area where an amount of data to be recorded is not determined, and the management information is recorded from a position separated outward from other management information already recorded on a management information recording area where an amount of data to be recorded is not determined.  
       [0009] Additionally, in a method for recording data and management information which manages the data onto a recording medium, each predetermined recording unit of the data is recorded from a position separated inward from other data already recorded on a data recording area where an amount of data to be recorded is not determined, and the management information is recorded from a position separated outward from other management information already recorded on a management information recording area where an amount of data to be recorded is not determined.  
       [0010] Other and further objects, features and advantages of the invention will appear more fully from the following description.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0011]FIG. 1 is an image diagram of data recording;  
     [0012]FIG. 2 is an image diagram of an optical disk;  
     [0013]FIG. 3 is a block diagram of a recording/reproducing apparatus; and  
     [0014]FIG. 4 is an image diagram of data recording. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0015] A recording/reproducing apparatus of a first embodiment will be explained in detail in the following. In this embodiment, a recording medium is a non-rewritable optical disk, and data is additionally recorded.  
     [0016]FIG. 1 shows file arrangement on an optical disk of this embodiment. FIG. 2 is an image diagram of recording areas on the optical disk. FIGS. 1, 2 use the common symbols.  
     [0017] A recording area  101  is comprised of sectors each having a predetermined data amount. Data of 2,048 bytes can be recorded onto each sector. The sectors are numbered sequentially, starting from the center of the disk. The sectors to be accessed can be specified using the sector numbers.  
     [0018] An anchor descriptor shows an area where management information is recorded. When a position of an area for file management is changed, an anchor descriptor is added to change a readout position of the management information area. When a plurality of anchor descriptors are recorded onto an anchor descriptor area, only the last anchor descriptor is recorded to decrease the frequency of the rewriting on the anchor descriptor area. The anchor descriptor includes not only a recorded position of the management information but also several pieces of information. The data amount of the anchor descriptor can be recorded sufficiently on one ECC block. One piece of additional recording of the anchor descriptor needs a data amount of 16 sectors equivalent to one ECC block.  
     [0019] In this embodiment, although data amounts of a data area and management information area are not previously determined, a data amount of an anchor descriptor area is previously determined. This is because if the anchor descriptor recording area is not previously determined, a starting position for recording the management information cannot be determined because the anchor descriptors are usually recorded from the inside of an optical disk. The number of anchor descriptors is proportional to the number of pieces of the management information. Thus, a data amount of the anchor descriptor area can be previously determined according to the frequency of the additional recording. For example, when the frequency of the additional recording is assumed to be 1,000 times, a data amount of the anchor descriptor area may be equivalent to 16,000 sectors. The anchor descriptors may not be recorded on the optical disk. In this case, the management information is recorded from the inside of the optical disk so that the recording area of the optical disk can be used more efficiently.  
     [0020] Management information  103  manages a recorded position, data amount, file identifier (file name), file generation time, or file type of data  104 ,  105  recorded on the optical disk.  
     [0021] The data  104 ,  105  are image or sound data recorded by a user.  
     [0022] Recording of data by a recording apparatus of this embodiment will be explained in the following with reference to FIGS.  1  to  3 .  
     [0023]FIG. 3 is a block diagram of a recording/reproducing apparatus of this embodiment.  
     [0024] First, recording of data 1 ( 104  in FIG. 1) will be explained.  
     [0025] The data 1 is the first data to be recorded on this optical disk. Before this recording, this optical disk is assumed to have no data.  
     [0026] When a new optical disk having no data is inserted into the recording/reproducing apparatus, the apparatus recognizes the insertion of the optical disk. A control microcomputer  308  notices the insertion to a main microcomputer  304  via an interface  307 . Then, the main microcomputer  304  recognizes that the inserted disk is an unused optical disk.  
     [0027] Because the unused optical disk has no anchor descriptor and management information, the main microcomputer  304  generates empty management information, which is not recorded onto an optical disk  312 .  
     [0028] Next, when instructed by a switch  306  to record the data 1, the main microcomputer  304  judges a data amount of the data 1, and instructs, via the interface  307 , the control microcomputer  308  to start recording of the data 1 from a sector of a predetermined number (a position of  106  in FIG. 1).  
     [0029] The main microcomputer  304  needs to previously judge an amount of data to be recorded. In recording image/sound data, an amount of the data can be calculated according to an average bit rate and recording time of the data. For example, when image/sound data of the data 1, which is a program of thirty minutes and encoded at an average bit rate of 6 Mbps, is recorded, the data amount is 1,350 M bytes (6 Mbps×1,800 seconds=10.8 G bits). When one sector has an amount of 2 KB, 67,500 sectors may be required. The outside of an unrecorded area, which outside contains 675,000 sectors, is used as the recording area. In other words, recording of the data 1 starts from a sector separated by 675,000 sectors inward from the outermost sector of the unrecorded area.  
     [0030] An average bit rate used for the recording is determined by the main microcomputer  304 , and set in a CODEC circuit  303 . On the other hand, a recording time of a TV program is previously determined. The main microcomputer  304  may also control the control microcomputer  308  and a data processing circuit  310  so that the recording time becomes equal to a predetermined time, according to the user&#39;s instruction. In recording a PC data file, whose amount is previously determined, the outside of the unrecorded area may be allocated to a recording area corresponding to the file amount.  
     [0031] Next, to record data from a sector (a position of  106  in FIG. 1) specified by the main microcomputer  304 , the control microcomputer  308  instructs a servo  313  to control, e.g., the rotational frequency of the optical disk  312  and a position of the optical head  311 .  
     [0032] The control microcomputer  308  causes the CODEC circuit  303  to compress the data 1. Image/sound data which is input from a sound input/output terminal  301  and image input/output terminal  302  is input to the CODEC circuit  303 , and A/D converted to digital data. The digitalized image/sound data is compressed by the CODEC circuit  303 . The image/sound data processed by the CODEC circuit  303  is stored in a buffer memory  309  via the interface  307 .  
     [0033] The control microcomputer  308  confirms an amount of the image/sound data stored in the buffer memory  309 . When the amount reaches a predetermined value, the control microcomputer  308  inputs the image/sound data from the buffer memory  309  to a data processing circuit  310 , and causes the data processing circuit  310  to record the data. In the data processing circuit  310 , the input data is encoded, for example added an error correcting code, and then modulated to be recorded onto an optical disk. The modulated data is recorded onto the optical disk  312  via the optical head  311 .  
     [0034] When the recording of the data 1 is completed, management information  103   a  including a recorded area, identifier (file name), and property of the data 1 is recorded from the inside of the management information area. Also a number of the last sector of the recorded area is recorded as the management information. This number is used for judging a position for the next additional recording.  
     [0035] An anchor descriptor  102   a  showing a sector number of the management information  103   a  is recorded onto the anchor descriptor area.  
     [0036] Next, recording of data 2 will be explained in the following.  
     [0037] When the optical disk having only the data 1 is inserted into, or power is applied to the recording/reproducing apparatus, the main microcomputer  304  is notified of the insertion of the optical disk.  
     [0038] The main microcomputer  304  reads out the anchor descriptor  102   a  recorded on the optical disk  312 . The main microcomputer  304  judges from the anchor descriptor  102   a  a recorded position of management information on the optical disk, reads out the management information  103   a , and stores the management information  103   a  in a RAM  305 . The anchor descriptor last recorded onto the anchor descriptor area is used as a valid anchor descriptor in order to accept the additional recording. The anchor descriptor may include a version number in order to judge whether the anchor descriptor is the latest.  
     [0039] When there is an instruction from the switch  306  to record the data 2, the main microcomputer  304  requires a number of a sector where the recording is started, according to the management information stored in the RAM  305 . This is because the data 2 needs to be recorded onto an area where the data 1 is not recorded. As described above, the data  1  has been recorded on the area for  104 . The last recorded portion is thus the last sector of the data  104 . This last sector number can be obtained from the management information  103   a . The main microcomputer  304  judges that the recording area for  104  is already fully used.  
     [0040] Next, the main microcomputer  304  judges an amount of the data 2, and instructs, via the interface  307 , the control microcomputer  308  to start recording the data 2 from a position ( 107  in FIG. 1) separated by an amount of the data  2  inward from the outermost periphery of an unrecorded area of the optical disk  312 .  
     [0041] The control microcomputer  308  instructs the servo  313  to control, e.g., the rotational frequency of the optical disk  312  and a position of the optical head  311  in order to start the data recording from a sector specified by the main microcomputer  304 .  
     [0042] Then, the control microcomputer causes the data processing circuit  310  to record the data 2 onto the optical disk  312 .  
     [0043] After the recording of the data 2 is completed, the management information  103   b  and the anchor descriptor  102   b  are recorded onto the management information area and the anchor descriptor area, respectively.  
     [0044] In this embodiment, because the management information  103  is recorded from the inside of the optical disk  312 , and the data  104  is recorded from the outside, there is no possibility that either the management information area or data area comes short or is partially unused. Thus, the recording areas on the disk are efficiently used.  
     [0045] The present invention is not limited to the above-described embodiment where the management information is recorded just after a file is recorded. When the management information is often updated, the update may be executed on the main microcomputer  304 , and the management information and anchor descriptor may be recorded only when the disk is ejected. This permits the frequency of additional recording of the anchor descriptors to decrease, and permits the areas on the disk to be more effectively used. In the above-described embodiment, the management information is recorded from the inside of the optical disk, and the data is recorded from the outside of the disk. The management information may be recorded from the outside of the optical disk, and the data may be recorded from the inside of the disk, obtaining the same effect as in the above-described embodiment. The recording medium is not limited to a non-rewritable optical disk. Any recording medium where data and management information can be recorded may be used. Data to be used is not limited to image/sound data. Program data for PCs also can be recorded.  
     [0046] Next, reproduction by the recording/reproducing apparatus of this embodiment will be explained in the following with reference to FIGS. 1, 3. The data 1, 2 has been already recorded on the optical disk.  
     [0047] First, when the optical disk is inserted into, or power is applied to the recording/reproducing apparatus, information about the insertion of the disk is sent from the control microcomputer  308  to the main microcomputer  304 . The main microcomputer  304  instructs the control microcomputer to read out information about a sector where an anchor descriptor is recorded. The control microcomputer  308  reads out the specified sector information, and sends the information to the main microcomputer  304 . As shown in FIG. 1, anchor descriptors  102   a ,  102   b  are recorded. Because anchor descriptors are additionally recorded, the last written anchor descriptor is judged to be a valid anchor descriptor. In FIG. 1, the anchor descriptor  102   b  is judged to be a valid anchor descriptor.  
     [0048] The main microcomputer  304  judges a recorded position of the management information from the anchor descriptor  102   b  which has been read out. The anchor descriptor  102   b  shows that the recorded position is  103   b . Thus, the main microcomputer  304  reads out and analyzes the management information  103   b.    
     [0049] The management information  103   b  includes identifiers, properties, and recorded areas of the data 1, 2.  
     [0050] The main microcomputer  304  notices to a user that the data 1, 2 is recorded, and prompts the user to select a file to be used. The file includes a PC data file and image/sound data such as a TV program and movie.  
     [0051] When a file is selected, the main microcomputer  304  judges a sector number of the selected file, and reproduces the data. The reproduced data is input into the CODEC circuit  303 . In the CODEC circuit  303 , after digitalized to expand, the data is D/A converted to analog image/sound data. The analog image/sound data is output to the image input/output terminal  302  and sound input/output terminal  301 , respectively. When the reproduced data is PC program data, it is sent to a PC to be then processed.  
     [0052] As a result, the data can be reproduced from the optical disk where the file is recorded.  
     [0053] A recording/reproducing apparatus of a second embodiment will be explained in the following with reference to FIGS. 3, 4. In this embodiment, a recording medium is a non-rewritable optical disk where data is recorded additionally.  
     [0054]FIG. 4 shows file arrangement on the optical disk of this embodiment.  
     [0055] A recording area  401  has sectors each having a predetermined data amount. The configuration of sectors, anchor descriptors, and management information is the same as that in the first embodiment.  
     [0056] First, data 1 ( 404  in FIG. 4) will be explained.  
     [0057] The first process of the recording/reproducing apparatus when a new optical disk having no data is inserted into the apparatus is the same as that in the first embodiment.  
     [0058] When the switch  306  instructs the main microcomputer  304  to record the data 1, the main microcomputer  304  causes the CODEC circuit  303  to compress the data 1. Image/sound data which is input from the sound input/output terminal  301  and image input/output terminal  302  is input into the CODEC circuit  303 , and A/D converted to digital data. The digitalized image/sound data is compressed by the CODEC circuit  303 . The compressed image/sound data is stored into the buffer memory  309  via the interface  307 .  
     [0059] The microcomputer  308  confirms an amount of the image/sound data stored in the buffer memory  309 . When the amount reaches a predetermined value, the microcomputer  308  inputs the image/sound data from the buffer memory  309  to the data processing circuit  310 , and causes the data processing circuit  310  to record the data. In the data processing circuit  310 , the input information is encoded, for example added an error correcting code, and then modulated to be recorded onto the optical disk. The modulated data is recorded onto the optical disk  312  via the optical head  311 .  
     [0060] Recording of the data 1 onto the optical disk will be explained in detail in the following.  
     [0061] In this embodiment, as shown in FIG. 4, the control microcomputer  308  divides the data 1 into blocks ( 404   a  to  404   c ) each having a plurality of sectors, and records the blocks onto a data recording area of the optical disk  312 . In this case, the control microcomputer records the blocks (a data amount of one block is equal to an integral multiple of an ECC block) sequentially from the outside (a sector of a larger sector number) to inside (a sector of a smaller sector number). In each block area, the recording is executed from the inside (a sector of a smaller sector number) to outside (a sector of a larger sector number).  
     [0062] As a result, in this embodiment, because each block has successive sector numbers, no seek operation (movement of the optical head) is executed in recording data in each block, not causing the data recording rate to fall.  
     [0063] On the other hand, when the optical head moves from one block to another, a head position of the next block needs to be detected by the seek operation, causing the data recording rate to fall.  
     [0064] When the data amount in each block is set small, the seek operation is often executed between the blocks to thereby fall the data recording rate. On the other hand, when the data amount in each block is set large, an empty area on the last recorded block becomes large to thereby often waste the recording area. Thus, the data amount of each block needs to be determined in consideration of these facts. In this embodiment, one block has 8 MB (4,096 sectors). This amount can be arbitrarily changed. An optimum data amount is determined according to, e.g., the data recording rate.  
     [0065] In this embodiment, an amount of the data 1 is 20 MB.  
     [0066] After the data is recorded onto the whole of an area  404   a , the optical head seeks the innermost periphery (sector of the smallest sector number) of an area  404   b . Then, the data 1 is recorded from the inside (a sector of a smaller sector number) to outside (a sector of a larger sector number).  
     [0067] Likewise, when the area  404   b  is fully recorded, an area  404   c  is used. Because the amount of the data 1 is 20 MB, the recording is completed on the way of the area  404   c , generating an empty area on the aft portion of the area  404   c . The empty area is fully buried with dummy data.  
     [0068] When the recording of the data 1 is completed, the management information  403   a  including a recorded area, identifier (file name), and property of the data 1 is recorded onto the management information area. Also a number of a sector where the information is last recorded is recorded as the management information. The number is used for judging a position for the next additional recording.  
     [0069] Finally, the anchor descriptor  402   a  showing a sector number of the management information  403   a  is recorded onto the anchor descriptor area.  
     [0070] Next, recording of the data 2 will be explained in the following.  
     [0071] When an optical disk having only the data 1 is inserted into, or power is applied to the recording/reproducing apparatus, the main microcomputer  304  is notified of the insertion of the optical disk.  
     [0072] The main microcomputer  304  reads out an anchor descriptor  402   a  recorded on the optical disk  312 . The main microcomputer  304  judges from the anchor descriptor  402   a  a recorded position of the management information on the optical disk, reads out the management information  403   a , and stores the management information  403   a  into the RAM  305 . The anchor descriptor last recorded onto the anchor descriptor recording area is used as a valid one for additional recording. The anchor descriptor may have a version number in order to judge whether the anchor descriptor is the latest.  
     [0073] When the main microcomputer  304  receives from the switch  306  an instruction to record the data 2, it requires, according to the management information stored in the RAM  305 , a number of a sector where the recording is started, the sector being on the optical disk  312 . This is because the data 2 needs to be recorded onto the recording area where the data 1 is not recorded. As described above, the data  1  is recorded in the order:  404   a ,  404   b ,  404   c . The last recorded portion is the last sector of the data  404   c . A number of the last sector is obtained from the management information  403   a . The main microcomputer  304  judges that the recording areas up to  404   c  have been already used.  
     [0074] The main microcomputer  304  instructs, via the interface  307 , the control microcomputer  308  to start data recording from a sector of a predetermined number.  
     [0075] The control microcomputer  308  instructs the servo  313  to control, e.g., the rotational frequency of the optical disk  312  and a position of the optical head  311  in order to execute data recording from a sector specified by the main microcomputer  304 .  
     [0076] When the data 2 is input, the recording starts from an area  405   a . When the area  405   a  is fully used, the data is recorded onto the areas in the order:  405   b ,  405   c . The recording of the data 2 is completed on an area  405   d . There is an empty area on the aft portion of  405   d . The empty area is buried with dummy data because it is not used.  
     [0077] Management information  403   b  including a recorded area of the data 2 is recorded onto the management information area. The management information  403   b  which is new contains management information about the data 1, 2.  
     [0078] To exhibit a recorded position of the management information  403   b , an anchor descriptor  402   b  is recorded after the anchor descriptor  402   a.    
     [0079] Effects of this embodiment are as follows. The management information is recorded from the inside of the disk, and the data is recorded from the outside of the disk, so that there is no possibility that either the management information area or data area comes short or is partially unused. As a result, the recording area on the disk can be effectively used. Additionally, proper data recording can be executed without calculating an amount of the data.  
     [0080] The present invention is not limited to the above-described embodiment where the management information is recorded just after the data recording. When the management information is often updated, the update may be executed on the main microcomputer  304 , and the management information and anchor descriptor may be recorded only when the disk is ejected.  
     [0081] As a result, the frequency of additional recording of the management information and anchor descriptors can be decreased so that the area on the disk can be used more efficiently.  
     [0082] Next, reproduction by the recording/reproducing apparatus of this embodiment will be explained with reference to FIGS. 3, 4.  
     [0083] The data 1, 2 has been already recorded on the optical disk.  
     [0084] When the optical disk is inserted into, or power is applied to the recording/reproducing apparatus, the main microcomputer  304  is notified of the insertion of the disk from the control microcomputer  308 . The main microcomputer  304  instructs the control microcomputer  308  to read out sector information recorded on an anchor descriptor. The control microcomputer  308  reads out information of the specified sector, and sends the information to the main microcomputer  304 . Like in the first embodiment, the anchor descriptor  402   b  is judged to be valid.  
     [0085] The main microcomputer  304  judges a recorded position of the management information from the anchor descriptor  402   b  which has been read out. The anchor descriptor  402   b  shows that a recorded position of the management information is  403   b . The main microcomputer  304  reads out and analyzes the management information  403   b.    
     [0086] The management information  403   b  includes identifiers, properties, and recorded areas of the data 1, 2.  
     [0087] The data 1 recorded on the optical disk  312  is reproduced by the optical head  311 . In the data processing circuit  310 , the data 1 is demodulated, and decoded, for example added an error correcting code. The decoded data is once stored in the buffer memory  309 . In this embodiment, after  404   a  is reproduced, it takes a predetermined time for the optical head  311  to seek the inside (position of a smaller sector number) of  404   b . However, by using the buffer memory  309 , a seek time of the optical head  311  can be absorbed to thereby reproduce the data successively. Like in the first embodiment, the data which is output from the buffer memory via the interface  307  to the main microcomputer  304  is input to the CODEC circuit  303 , digitalized, D/A converted, and output to the sound input/output terminal  301  and image input/output terminal  302 .  
     [0088] As a result, the data can be reproduced from the optical disk.  
     [0089] In the second embodiment, the recording blocks are recorded from the outside. However, a sector number of the outside is not always higher, e.g., on a disk having upper and lower recording layers. The sector number may increase from the inside to outside on the first layer, and may increase from the outside to inside on the second layer. Also in this case, the same effects can be obtained using the present invention, when sectors in each block are recorded sequentially in the descending order of their sector numbers.  
     [0090] This embodiment is applicable to not only a non-rewritable optical disk but also any recording medium where data and management information can be recorded. This embodiment is also applicable to not only image/sound data but also program data for PCs.  
     [0091] According to the present invention, a recording method for efficiently using a recording area on a recording medium can be provided.  
     [0092] The foregoing invention has been described in terms of preferred embodiments. However, those skilled, in the art will recognize that many variations of such embodiments exist. Such variations are intended to be within the scope of the present invention and the appended claims.