Dynamic information storage or retrieval – Binary pulse train information signal – Binary signal gain processing
Reexamination Certificate
1998-02-09
2001-04-10
Edun, Muhammad (Department: 2753)
Dynamic information storage or retrieval
Binary pulse train information signal
Binary signal gain processing
C369S053130, C369S047360, C369S053130
Reexamination Certificate
active
06215750
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to data recording/reproducing apparatus and method corresponding to a plurality of data formats and a data recording medium.
2. Description of the Prior Art
As an external memory apparatus of a computer, attention is paid to an optical disc drive from a viewpoint of advantages of a large capacity and a high-speed access. The use of a CD-ROM [or CD-I (CD Interactive)] drive and an MO (magneto-optical disc serving as one of erasable discs) drive has already rapidly been being spread. In addition to those discs, an MD (mini disc; erasable disc) having a disc diameter of 2.5 inches has also been proposed. Further, a DVD (digital video disc) is being developed as a video memory medium.
The DVD is a read only disc having the same diameter as that of the CD or a recordable/reproducible optical disc such as MO disc or phase-change type disc. The DVD is a disc in which video information compressed by an MPEG or the like can be reproduced or can be recorded and reproduced. In the DVD, by the improvement of processes such as digital modulation and error correction encoding in association with the progress of the realization of a short wavelength of a laser beam and an increase in numerical aperture NA of an objective lens, a recording density is further raised. Even in case of a single-layer disc, a data memory capacity is very large to be about 3.7 Gbytes. In a manner similar to the CD and MD which have first been developed as digital audio discs and, after that, they are also used as external memory media of computers, it is expected that the DVD having a larger capacity is used as an external memory medium of the computer.
Hitherto, since different formats have been specified for every medium such as magnetic tape, magnetic disc, flexible disc, above-mentioned optical discs, and the like, respectively, a consideration about a compatibility is not made. Therefore, in case of obtaining a compatibility between a new medium and the existing medium, such a compatibility can correspond in only a logical region, so that it is not efficient. For example, in case of an external memory medium of a computer, a sector size of (128 bytes×
2
i
)(512 bytes, 2 kbytes, or the like) is a main stream. In the CD-ROM, 2352 bytes (in case of excluding a synch signal, 2340 bytes; in case of excluding the synch signal and a header, 2336 bytes) is set to one block. Thus, there is a problem such that it is difficult for both of them to physically correspond to each other. Further, as a sector size according to the CD format including the CD-ROM, when considering a sub-code as well, there are other various sizes.
The above-mentioned DVD can be realized even by a recordable MO disc or a phase-change type disc, so that there is an advantage such that when comparing with a capacity of any one of the other existing optical discs, a capacity of the DVD is remarkably large. In case of newly using such a DVD as an external memory medium, it is indispensable to consider the compatibility with the existing optical disc media, especially, the CD-ROM which has been widespread and has almost the same disc size and uses the same reading method in order to simplify the mutual transmission and reception of data between the CD-ROM and the DVD, to enable the drive to be shared, and further, to effectively use the resources of the CD-ROM.
In JP-A-7-73593, the inventors et al. of the present invention have proposed the method of setting a memory capacity per one recording block unit of the MO disc to 2352 bytes in order to simplify the data transmission and reception between the CD-ROM and the MO disc. According to the method, the memory capacity per one recording block of the MO disc is matched with that of the CD-ROM. There is a problem such that although such a method can be applied to a case where a data structure of the disc is newly decided, it cannot be applied to a case where the data structure of the disc has been standardized to a certain degree.
As mentioned above, in the data recording/reproducing apparatus in which a plurality of sector sizes are permitted, ordinarily, a different format is specified every data having a different sector size and signal processes for recording and reproduction are made independent every format. According to such a method, there is a problem that a scale of a hardware for recording and reproduction increases. As another method, there is a method whereby data having different sector sizes is fundamentally recorded and reproduced in the same format, an identification (ID) signal is inserted to a directory area or a header area as additional information, and the sector size is recognized by the ID signal.
The method of inserting the ID information of a sector size into the additional information has an advantage such that a hardware can be partially shared. However, there is a problem with respect to a point of an accessing performance. Generally, in case of recording and reproducing digital data, a digital modulation such as an EFM or the like is generally performed to data in order to improve an error rate and to enable a clock to be easily extracted. The additional information as mentioned above has been also modulated. Therefore, the ID information cannot be obtained upon reproduction unless a process for demodulation is finished. A sector size of data which was reproduced so far cannot be known, so that the accessing performance deteriorates.
OBJECTS AND SUMMARY OF THE INVENTION
It is, therefore, an object of the invention to provide data recording/reproducing apparatus and method and data recording medium which can smoothly perform a data compatibility between two or more different data structures, more particularly, two or more data structures having different sector sizes.
Another object of the invention is to provide data recording/reproducing apparatus and method and data recording medium which enables a sector of a size according to a CD format to be easily packed to a predetermined block, thereby enabling data according to the CD format to be easily transferred.
Further another object of the invention is to provide data recording/reproducing apparatus and method and disc medium in which when two or more data structures having different predetermined units of data such as a sector size or the like are enabled to be processed, a scale of a hardware is small and a good accessing performance can be obtained.
To accomplish the above objects, according to the invention, there is provided a data recording apparatus for recording digital data to a recordable optical disc, comprising: input means for receiving at least two digital data in which a ratio between sector sizes is not an integer ratio; means for inserting data nA and data mB (n and m are integers of 2 or more and n ≠m) into a block of a predetermined size when it is assumed that a sector size of first data is set to A and a sector size of second data is set to B, thereby forming data of a block structure; recording processing means for executing an error correction encoding and a digital modulation for the data of the block structure; and recording means for recording the recording data from the recording processing means to the optical disc. According to the invention, there is also provided a recording method of recording data as mentioned above.
According to the invention, there is provided a data reproducing apparatus for reproducing an optical disc in which digital data of a block structure of sizes in which a ratio between a sector size A of first data and a sector size B of second data is not an integer ratio and data nA and mB (n and m are integers of two or more and n≠m) can be inserted has been recorded, comprising: means for reproducing the digital data; reproduction processing means for performing a digital demodulation and an error correction to the data of the block structure; means for dividing the data of the block structure from the reproduction processing means into sectors and for outputting the data of a se
Sako Yoichiro
Yamagami Tamotsu
Edun Muhammad
Limbach & Limbach LLP
Sony Corporation
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