Recording medium and reproducing apparatus thereof

Abstract: In a PVD table of a management region on the disc, a disc identifier 1 that represents the type of the data recording format of the disc, a number-of-disc-sides identifier 2 that represents whether the disc is a single-sided disc or a double-sided disc, and a disc side identifier 3 that represents whether the reproducing disc is side A or side B of a double-sided disc. A disc identifier 4 that represents the type of the data recording format of the file is recorded in a file (n) table including management information of the file. The reproducing apparatus reads the disc identifiers 1 and 4 from the PVD table and the file (n) table and determines whether or not the disc and the file are reproducible. In addition, the reproducing apparatus reads the number-of-disc-sides identifier 2 from the PVD table and determines whether or not the disc is a double-sided disc or a single-sided disc. When the disc is a double-sided disc, the reproducing apparatus determines whether the reproducing side is side A or side B.

Description: The present invention relates to a recording medium such as an optical disc and a reproducing apparatus thereof. Generally, management information is recorded on an optical disc. The management information manages data (files) recorded on the optical disc. As a representative example, management information defined as ISO-9660 standard is known. The management information includes at least ID information and the size of each disc, the number and reproducing order of discs that correlate, and the ID information, the record position, and the size of each file recorded on the disc as structural elements. However, in recent years, discs that have the management information corresponding to the ISO-9660 standard are categorized as various types such as specific discs, single-sided discs, and double-sided discs. However, the conventional management information does not include information that distinguishes such disc types. EP-A-0 570 203 on which the preamble of the appended claims is based describes reproducing apparatus which is compatible with both single-sided and double sided optical discs. An optical disc is placed in a cartridge 23 having two sensor holes, A and B. Sensor hole A, for example, indicates whether the disc is double-sided or single-sided and sensor hole B discriminates between the sides. A sensor is provided (in the reproducing apparatus) for detecting whether holes A and B are open or closed. Furthermore, in an access mode registration area 27 the type of disk is identified as being a single-sided disk with one volume, a double-sided disk with one volume or a double-sided disk with two volumes. EP-A- 0 510 871 describes a recording medium on which data is recorded, and a reproducing apparatus therefore. The most significant byte S of byte 8 of the data recorded on the recording medium is an identification flag of side A/B, whereby S = O represents side A and S = 1 represents side B. An object of the present invention is to provide a recording medium and a reproducing apparatus thereof that determine the number of recording sides and a recording surface thereof. To accomplish such object, a first aspect of the present invention is a recording medium having two opposite sides, either one or both of which being selective as recording sides, comprising a data region in which data is recorded and a management region including number-of-recording-layers identifying information that represents the number of recording layers of the recording medium; characterised in that the management region in case of a disk with two opposite recording sides also includes recording side identifying information that represents the recording side. A second aspect of the present invention is a reproducing apparatus, comprising a reproducing apparatus for reproducing a recording medium having two opposite sides, either one or both of which being selective as recording sides, including a data region in which data is recorded, and a management region including number-of-recording-layers identifying information that represents the number of recording layers of the recording medium, the reproducing apparatus comprising: number-of-recording-layers determining means for reading the number-of-recording-layers identifying information recorded in the management region and determining the number of recording layers of the recording medium; characterised in that the management region of the recording medium in case of a disk with two opposite recording sides includes recording-side identifying information that represents the recording side, and in that the reproducing apparatus comprises recording-side determining means for reading in case of a disk with two opposite recording sides the recording-side identifying information recorded in the management region and determining the recording side of the recording medium to be reproduced. Thus, according to the present invention, different types of recording mediums that are for example single-sided type and double-sided type can be handled. These and other objects, features and advantages of the present invention will become more apparent in light of the following detailed description of a best mode embodiment thereof, as illustrated in the accompanying drawings. Fig. 1 is a schematic diagram showing a data structure of an optical disc according to an embodiment of the present invention; Fig. 2 is an example of PVD table; Fig. 3 is an example of VTD table; Fig. 4 is an example of L type PT table; Fig. 5 is an example of M type PT table; Fig. 6 is an example of DR(00) table; Fig. 7 is an example of DR(01) table; Fig. 8 is an example of file (n) table; Fig. 9 is a block diagram showing a construction of an optical disc reproducing apparatus that reproduces data from the disc shown in Fig. 1; Fig. 10 is a block diagram showing a construction of a function that determines the types of a disc and a file corresponding to a data recording format; Fig. 11 is a block diagram showing a construction of a function that determines the number of recording sides and a reproducing side of a disc; Fig. 12 is a schematic diagram showing a file access process of a data structure; Fig. 13 is a flow chart showing a file access process; Fig. 14 is a schematic diagram showing disc management information multiplexedly written to a read-in region; Fig. 15 is a schematic diagram showing a data structure of a file; Fig. 16 is an example of a file management table; Next, with reference to the accompanying drawings, an embodiment of the present invention will be described. Fig. 1 a schematic diagram showing a data structure of an optical disc according to an embodiment of the present invention. The data structure of the disc is based on ISO-9660 standard. The record space of the disc is divided into a read-in region, a management region, a data region, and a read-out region. The management region includes a system area, a PVD (Primary Volume Descriptor) table, a VTD (Volume Terminate Descriptor) table, a PT (Path Table), and a DR (Directory Record). The data region is composed of a plurality of files. As shown in Fig. 2, in the PVD table of the management region, information of the disc (volume) such as the size of the volume, the attribute of the volume, the position of the route DR, and the position of the PT is written. The content of the VTD table is defined as shown in Fig. 3. In the PT (L type PT or M type PT), as shown in Figs. 4 and 5, hierarchical structures between DRs are written. The DR is a table group that are composed of a route DR (00) table, a route DR (01) table, and a file (n) table. In the route DR (00) table and the route DR (01) table, as shown in Figs. 6 and 7, the positions thereof are written. The file (n) table is provided for each file in the data region. As shown in Fig. 8, in the file (n) table, the position of the file and so forth are written. As shown in Fig. 2, the PVD table is provided with an application system region. In the application system region, a disc identifier 1, a number-of-disc-sides identifier 2, a disc side identifier 3, and so forth are recorded. The disc identifier 1 represents the type of the data recording format of the disc. The number-of-disc-sides identifier 2 represents whether the disc is a double-sided disc or a single-sided disc. The disc side identifier 3 represents whether side A or side B of a double-sided disc is being reproduced. In the PVD table, the value of the BP represents the byte position from the top of the table. As shown in Fig. 8, the file (n) table corresponding to each file is provided with an application system region. In the application system region, information (disc identifier) 4 and so forth are recorded. The disc identifier 4 represents the type of the data recording format of the file. Fig. 9 is a schematic diagram showing a construction of an optical disc reproducing apparatus that reproduces data from a disc that has the above-described data structure. In Fig. 9, reference numeral 11 is an optical disc drive portion that drives the optical disc and reads data from the optical disc through an optical pickup. Reference numeral 12 is an MPU (Micro Processor Unit) that controls the entire system of the apparatus. Reference numeral 13 is a key input portion that supplies a user command to the MPU 12. Reference numeral 14 is an RAM portion that is used as a working region for a ROM and the MPU 12. In the ROM, a control program for the MPU 12 is stored. Reference numeral 15 is a system processor portion that demodulates and error-corrects the data that is output from the optical drive portion 11 and divides the error-corrected data into three types of data that are video (main image), audio, and sub video. Reference numeral 16 is a RAM portion that processes data. Reference numerals 17, 18, and 19 are a video decoder portion, an audio decoder portion, and a sub video decoder portion that decode the video data, the audio data, and the sub video data that are output from the system processor portion 15, respectively. Reference numeral 20 is a D/A & reproducing process portion that converts each decoded data into an analog signal, multiplexes the video data and the sub video data, and outputs the multiplexed data to an image and sound output portion 21. Next, with reference to Figs. 10 to 13, the operation of the optical disc reproducing apparatus will be described. Fig. 10 is a block diagram showing a construction of a function that determines the types of a disc and a file corresponding to the data recording format of the disc. Fig. 11 is a schematic diagram showing a construction of a function that determines the number of recording sides of the disc and the reproducing side. Fig. 12 is a schematic diagram showing a file access process of the data structure shown in Fig. 1. Fig. 13 is a flow chart showing a file access process. After the disc reproducing apparatus is activated or the disc is replaced, the reproducing apparatus reads the PVD table (at step 1). Thereafter, the reproducing apparatus determines whether or not the disc is based on the ISO-9660 standard corresponding to the standard identifier in the PVD table (at step 2). When the disc is based on the ISO-9660 standard, a disc recording format determining portion 31 of the reproducing apparatus checks the disc identifier 1 recorded in the application system region of the PVD table and determines whether or not the reproducing apparatus can reproduce data from the disc (applicable disc) (at step 3). When the mounted disc is an applicable disc, a number-of-disc-recording-sides determining portion 41 of the reproducing apparatus determines the number-of-disc-sides identifier 2 recorded in the application system region (at step 4). When the mounted disc is a double-sided disc, a disc side A/B determining portion 42 of the reproducing apparatus checks the disc side identifier 3 recorded in the application system region and determines whether the reproducing side is side A or side B (at step 5). Thereafter, the reproducing apparatus reads the PT and determines the hierarchical structure between the DRs. Next, the reproducing apparatus reads the route RD and determines the position of each file (n) table (at step 6). After that, the reproducing apparatus obtains a file name from the first file (n) table (at step 7) and determines whether or not the file name matches a predetermined file name (at step 8). When these file names do not match, the reproducing apparatus obtains the next file name (at step 9) and repeats the same operation. When these files match, a file record format determining portion 32 shown in Fig. 10 of the reproducing apparatus checks the information (disc identifier) 4 in the application system region of the file (n) table in the matched file and determines whether or not the file is applicable for the reproducing apparatus (at step 11). When the file is not applicable, the process is terminated. When the file is applicable, the reproducing apparatus checks the record position of the file corresponding to the file (n) table and accesses the file (at step 12). Next, the multiplex recording method of the management information will be described. On the disc, the same management information as the information recorded in the management region is multiplexedly recorded at a plurality of positions other than the positions of the management region and the data region. Fig. 14 shows the spare management information that is multiplexed written at a plurality of positions in the read-in region. As shown in Fig. 14, the values that represent the positions of individual spare management information are defined by the relative distance (number of sectors) from the top addresses of the spare management regions 51 and 52. The absolute addresses that represent the positions in a management region 53 and a data region 54 are defined by the relative distance (the number of sectors) from the top address of the management region 53. Thus, when any position of the spare management region 51 or 52 is accessed, by adding the value of a desired absolute address and an offset value of the top address of the spare management region 51 or 52, the value of the absolute address can be calculated. For example, when the top address of the first spare management region 51 is - 20, the address represented by the absolute address 3 is calculated by the following expression. 3 + (-20) = -17 Likewise, when the top address of the second spare management region 52 is -10, the address represented by the absolute address 3 can be calculated by the following expression. 3 + (-10) = -7 Next, the data structure of the file recorded in the data region of the disc will be described. Fig. 15 is a schematic diagram showing the data structure of the file. As shown in Fig. 15, the file includes a file management table 5, a group of chain information tables 6, a group of cell information tables 7, a group of DUT allocation tables (referred to as DATs) 8, and a group of DUTs (data units) 9. As shown in Fig. 16, the file management table 5 includes the number of chain information tables, the number of cell information tables, the number of DUTs (data units), the number of sectors, and pointers that represent the top of each table. Although the present invention has been shown and described with respect to a best mode embodiment thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omissions, and additions in the form and detail thereof may be made therein without departing from the scope of the appended claims.

Claims: A recording medium having two opposite sides, either one or both of which being selective as recording sides, comprising: a data region in which data is recorded; and a management region including number-of-recording-layers identifying information that represents the number of recording layers of the recording medium; characterised in that the management region in case of a disk with two opposite recording sides also includes recording side identifying information that represents the recording side. A reproducing apparatus for reproducing a recording medium having two opposite sides, either one or both of which being selective as recording sides, including a data region in which data is recorded, and a management region including number-of-recording-layers identifying information that represents the number of recording layers of the recording medium, the reproducing apparatus comprising: number-of-recording-layers determining means for reading the number-of-recording-layers identifying information recorded in the management region and determining the number of recording layers of the recording medium; characterised in that the management region of the recording medium in case of a disk with two opposite recording sides includes recording-side identifying information that represents the recording side, and in that the reproducing apparatus comprises recording-side determining means for reading in case of a disk with two opposite recording sides the recording-side identifying information recorded in the management region and determining the recording side of the recording medium to be reproduced.

Inventors: KIKUCHI SHINICHI, KITAMURA TETSUYA, MIMURA HIDEKI, TAIRA KAZUHIKO, KIKUCHI, SHINICHI, KITAMURA, TETSUYA, MIMURA, HIDEKI, TAIRA, KAZUHIKO
Applicants: TOSHIBA AVE KK, TOSHIBA KK, KABUSHIKI KAISHA TOSHIBA, TOSHIBA AVE CO., LTD
Application year: 1995
Main classification: G11B19
IPC codes: H04N5, G11B27, H04N9, G11B20, G11B7, G11B19