JPH06176504A - Optical disk recording and reproducing method - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] Immediate reading and reliability of information by adding code error detection code to header data and both code error detection code and code error correction parity to subheader data. It is possible to select the security. [Structure] The first code error detection code adding section 3 checks whether or not there is a code error in the subheader data 2 representing the attribute of the main data 1 such as a video signal or a music signal, and the main data 1 and the subheader data 2 are checked. The first time division multiplexing unit 4 performs multiplexing, and the code error correction parity adding unit 5
Is calculated and added. The second code error detection code adding section 7 checks the presence or absence of a code error in the header data 6 representing the physical position of the disk, and the PLL clock pull-in data VF for facilitating the reading of the header data 6.
The second time division multiplexing unit 9 multiplexes together with the synchronization signal from the synchronization signal 8 representing O or the beginning of the sector, and outputs the recording signal 11 modulated by the digital modulation unit 10 to the optical disc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to main data such as a video signal and a music signal which are digitized on an optical disk such as a magneto-optical disk, a phase change type disk and a plastic disk, and sub-header data representing this attribute. The present invention relates to a method of recording and reproducing header data or the like that represents the physical position of a disc on which data is written.

[0002]

2. Description of the Related Art The diameter of a typical optical disk is
A compact disc, in which a digitized music signal is mainly recorded on a 12 cm plastic disc and is intended for reproduction only, is well known, and further developed,
There is a CD-ROM as a device that can be used as a mass storage device for personal computers and office automation equipment. The CD-I is a CD-ROM disc on which moving images, voices, and computer codes are mixedly recorded.

A conventional system will be described below with reference to the drawings.

FIG. 4 shows an example of the data structure of a conventional CD-ROM.
(Fig. 4 (1)) and three modes of CD-ROM (Fig. 4 (1))
The relationships (2), (3), and (4) are also shown. In a CD for digital audio, 24 bytes of music data are recorded in one frame, and this constitutes 98 frames, that is, 2352 bytes, 1/75 seconds constitutes one block. Using this user data area of 2352 bytes, one sector of the CD-ROM is constructed.
As shown in (2), (3), and (4) of FIG.
The byte header is common, and the modes are divided according to the usage of other areas. Mode 0 shown in FIG. 4 (2) is 2336
Bytes are all "0" data, mode 1 shown in Fig. 4 (3)
Has two parities of P and Q recorded in 2048 bytes of user data and 288 bytes of auxiliary data, and further error correction is performed on the data after the error correction called CIRC based on the CD format is performed. You can do it. In mode 2 shown in FIG. 4 (4), all 2336 bytes are for user data.

FIG. 5 shows an example of a conventional CD-I data structure. The CD-I is a format defined under the mode 2 ((1) in FIG. 5) of the CD-ROM. CD-
I has two forms (FIGS. 5 (2) and (3)), and some have a header after the header. CD-
The ROM (FIG. 4) is provided with a header, and the CD-I (FIG. 5) is provided with a header and a sub-header, which describe data attributes. Images, music, and computer data are processed with such a data structure.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
Both OM and CD-I can handle moving images, music data, etc., but in order to realize a high compression rate for moving image data using high-efficiency encoding technology, which is expected to become mainstream in the future, in order to achieve high compression rate Of these, processing using inter-frame correlation is performed, and therefore, it is necessary to always find the head data of the processing unit during reproduction. In order to display the sector in which the head data is written, the data is written in the header or subheader.

This header or sub-header data is sought, and if it is not the desired frame data,
Immediately, unless re-seek is performed, high-speed search, which is a feature of optical disks, cannot be realized. Some CD-ROMs and CD-Is have an error detection code (EDC) added to the header and user data as shown in FIGS. 4 and 5, and others do not. An EDC is added to the header. These are protected against errors, but since EDC is commonly applied to 2048 bytes of user data, they cannot be read immediately after reading the header and sub-header. However, there is a problem in that it is vulnerable to an error when the EDC is not added.

In a recordable / reproducible optical disk for a computer or OA, an EDC is provided in the header, but the header data is limited to only the physical address data of the disk, and the user data of the user data is recorded. The attributes, their description areas, methods, etc. differ from user to user, and there are problems such as incompatibility.

Further, the CD-ROM and CD-I are basically intended for reproduction only, and include a sync signal, a header, and
The sub header and user data are intended for the original music C
Since the structure is integrally written with the user data for music data of D, if this is applied to an optical disc intended for rewriting, all the sectors to be rewritten must be rewritten at the same time. , There is a possibility that contradiction may occur in the address data representing the physical position of the disk as the header data.

In view of the above points, the present invention is an optical disk recording in which the header and sub-header can be read immediately even if there is an error detection code (EDC), sufficient error countermeasures can be taken, and compatibility between users is possible. And a reproducing method.

[0011]

According to the optical disc recording method of the present invention, it is first determined whether or not there is a code error in sub-header data representing an attribute of main data such as a video signal or a music signal.
Of the main data and the sub-header data, and the main data, the sub-header data, and the code error detection of the sub-header data. The code error correction parity addition section for the code arithmetically adds the code error correction parity, and the second code error detection code addition section checks the presence / absence of a code error in the header data representing the physical position of the disk. PLL clock pull-in data VF for facilitating data reading
A second time division multiplex of a synchronization signal indicating the beginning of O or a sector, a synchronization signal indicating the beginning of the data part of the sector, the data after the addition of the code error correction parity, and the second header data with the code error detection code. It is characterized in that a recording signal multiplexed by the digitizing unit and modulated by the digital modulating unit is output.

That is, in order to carry out the above-mentioned optical disc recording method, for recording, main data, header data, sub-header data, synchronization signal, first code error detection code addition section, second code error detection code addition section , A first time division multiplexing unit, a second time division multiplexing unit, a code error correction parity addition unit and a digital modulation unit.

The optical disk reproducing method of the present invention reproduces digital data such as a video signal or a music signal, sub-header data representing the attribute thereof, and header data representing the physical position of the optical disk in which these data are written. The signal is demodulated to the original data by the digital demodulation unit, and the synchronization signal at the beginning of the sector or the beginning of the data portion of the sector is extracted by the synchronization signal extraction unit. The first code error detection unit detects a code error of the header data representing the physical position of the disc, and detects the code error of the main data such as the video signal or the music signal and the sub-header data representing this attribute. The code error is corrected by the code error correction unit and output as main data, and the code error of the sub header data is detected by the second code error detection unit. And, one of the sub-header data code error correction previous sub header data and code error correction later is selected by the selector, and outputs the sub-header data.

That is, in order to carry out the above optical disc reproducing method, at the time of reproduction, a digital demodulating unit, a synchronizing signal extracting unit, a first code error detecting unit, a code error correcting unit, a second code error detecting unit and a selector are provided. Be prepared.

[0015]

According to the present invention, the header data indicating the physical position of the disk, the data representing the start data of the processing unit in the moving image data using the high-efficiency encoding technology which is expected to become mainstream in the future, and the data It is also possible to protect the sub-header data that represents the attribute of the error detection code with an error detection code and to read it without waiting for the decoding process of the code error correction with a large processing delay unique to the sector. In a rewritable optical disc, it is possible to separate the header data representing the physical position peculiar to the disc and the sub-header data which should be rewritten together with the data accompanying the data. It is possible to provide a recording and reproducing method of header and subheader data.

[0016]

1 is a block diagram showing the construction of an apparatus for realizing a recording method in a first embodiment of the present invention, and FIG. 2 is a sector data construction diagram.

In FIG. 1, 1 is main data, 2 is subheader data, 3 is a first code error detection code addition unit, 4 is a first time division multiplexing unit, 5 is a code error correction parity addition unit, Reference numeral 6 is header data, 7 is a second code error detection code addition unit, 8 is a synchronization signal, 9 is a second time division multiplexing unit, 10 is a digital modulation unit, and 11 is a recording signal.

The recording method in the first embodiment will be described below with reference to FIGS. 1 and 2. The sub-header data 2 representing the attributes of the main data 1 such as a video signal or a music signal is checked for the presence of a code error in this data during reproduction, so that the first code error detection code adding section 3
Then, the first code error detection code (EDC) 21 is added,
It is input to the first time division multiplexing unit 4 together with the main data 1 and, as shown in FIG. 2, the sub header data 2 is multiplexed so as to be located at the head of the data portion of the sector.

The multiplexed data is sent to the code error correction parity adding section 5 as shown in FIG. 2, where the first code error detection code 21 of the main data 1, the sub header data 2, and the sub header data 2 is sent. A parity C1 (22) and a parity C2 (23) for code error correction are calculated and added.

The data after the code error parity is added is input to the second time division multiplexing unit 9. Since the header data 6 representing the physical position of the disc is checked for the presence or absence of a code error relating to it at the time of reproduction, the second code error detection code adding section 7 makes it possible to detect the second data as shown in FIG. A code error detection code (EDC) 20 is added and input to the second time division multiplexing unit 9.

Also, the clock pull-in VFO data of the PLL for facilitating the reading of the above-mentioned header data 6, the synchronization signal indicating the beginning of the sector, and the synchronization signal 8 indicating the beginning of the data portion of the sector are also at the second time. It is input to the division multiplexing unit 9. These data are multiplexed so as to have a structure as shown in FIG. After that, the digital modulator
Digital modulation suitable for high density recording is performed at 10 and recorded as a recording signal 11 on an optical disc (not shown).

Next, a second embodiment will be described. FIG. 3 is a block diagram showing the configuration of an apparatus for realizing the reproducing method in the second embodiment.

In FIG. 3, 30 is a reproduced signal, 31 is a digital demodulation section, 32 is a synchronizing signal extraction section, 33 is a first code error detection section, 34 is a code error correction section, and 35 is a second code error detection section. 1. Reference numeral 36 is a selector, and 36 is a selector. As in FIG. 1, 1 is main data, 2 is subheader data, and 6 is header data.

The reproducing method in the second embodiment will be described below.

The reproduced signal 30 from the optical disk (not shown) is binarized and returned to the original data by the digital demodulation unit 31,
The sync signal extraction unit 32 extracts the sync signal 8 at the head of the sector or the head of the data portion of the sector. With the synchronization signal 8 at the head of the sector as a reference, the first code error detection unit 33 checks whether or not there is an error in the header data 6 which is written after that and represents the physical position of the disk. In this case, the header data 6 is written multiple times, and error-free header data is adopted, or correct header data is read out by the majority decision between the error-free header data.

As a result, it is determined whether the position is the desired position. If it is the desired data, the data written after that is the second code error detection unit 35 and the code error correction unit.
Sent to 34. The second code error detection unit 35 performs code error detection only on the sub-header data 2 representing the attribute of the main data 1 such as a video signal or a music signal.
Here, for example, it is immediately determined whether it is the head sector of the compression unit of the video signal compressed by the high-efficiency encoding technique,
If the sector is not the desired sector, immediate re-seek is performed.

On the other hand, in the code error correction unit 34, the above-mentioned subheader data 2 and the first subheader data shown in FIG.
The code error detection code 21 and the code error correction for the main data 1 are executed using the parity C1 (22) and the parity C2 (23). The sub-header data 2 described above, which does not require immediate judgment, can also be read after this error correction is completed. Therefore, the sub-header data 2 can select data before and after error correction, and the selector 36 plays the role. However, as a design problem, in the case to be decided either in advance, this selector is not necessary. The data after error correction is taken out as main data 1. It is obvious that the header data 6 is obtained from the output of the first code error detection unit 33.

Next, a third embodiment of the present invention will be described.

In a rewritable optical disc, digital data such as a video signal or a music signal, sub-header data showing the attribute thereof, and header data showing the physical position of the optical disc where these data are written are stored on the optical disc. It is convenient for the physical writing of to be clearly distinguished.

In FIG. 2, subheader data 2 representing the attributes of main data 1 such as a video signal or a music signal.
The first code error detection code 21 for checking the presence or absence of this code error, and the code error correction parity C1 (22) and parity C2 (23) related to the main data 1 are optically recorded in the data recording section in the sector. Header data 6 which is recorded as rewritable data by a change in reflectance or a change in the direction of magnetization, and a second code error detection code (EDC) 20 for checking the presence or absence of this code error.
The PLL clock pull-in VFO data for facilitating the reading of the above-mentioned header data 6, the sync signal indicating the beginning of the sector, and the sync signal 8 indicating the beginning of the data portion of the sector are embossed, that is, pit irregularities. It is recorded in a non-rewritable form.

By thus dividing the header data 6 according to the purpose and formatting it as pre-pits at the time of manufacturing the disk, the time and effort for initialization as seen in a floppy disk and the like can be saved, and the reference data can be mistakenly used for rewriting. The main data 1 to be rewritten and the sub-header data 2 representing its attribute are rewritten at the same time as the main data 1 is rewritten.

When data is recorded on a rewritable optical disk, a margin gap is provided in FIG. 2 at the boundary between sectors to prevent recording failure due to rotational fluctuation. Similarly, a gap is also provided at the delimiter between the second code error detection code 20 following the header data section and the synchronization signal 8 in the data section.

By the way, the header data 6 is, for example, a track number and a sector number, and the sub-header data 2 is, for example, a frame representing the beginning of a unit of compression processing of a video signal, a sampling frequency, the number of bits, and the like.

[0034]

As described above, according to the optical disc recording and reproducing method of the present invention, the header data indicating the physical position of the disc is used by using a magneto-optical disc, a phase change type disc, a plastic disc or the like. Data that represents the beginning data of a processing unit such as video data that uses high-efficiency coding technology that is expected to become mainstream in the future,
It is possible to find the sub-header data that represents the data attribute by protecting the error detection code without waiting for the decoding process of the code error correction with a large processing delay unique to the sector, or even after the decoding of the code error correction. In addition, rewriting is possible by separating the header data that represents the physical position unique to the disc on the rewritable optical disc from the subheader data that should be rewritten together with the data every time the data is rewritten. It is possible to provide a method for recording and reproducing the header and subheader data of an optical disc.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an apparatus that implements a recording method according to a first embodiment of the present invention.

FIG. 2 is a data structure diagram of a sector.

FIG. 3 is a block diagram showing a configuration of an apparatus that realizes a reproducing method according to a second embodiment of the present invention.

FIG. 4 is an explanatory diagram of a data structure of a conventional CD-ROM.

FIG. 5 is an explanatory diagram of a data structure of a conventional CD-I.

[Explanation of symbols]

1 ... Main data, 2 ... Subheader data, 3 ... 1st code error detection code addition part, 4 ... 1st time division multiplexing part, 5 ... Code error correction parity addition part, 6 ... Header data, 7 ... A second code error detection code adding section,
8 ... Sync signal, 9 ... Second time division multiplexing unit, 10 ... Digital modulation unit, 11 ... Recording signal, 20 ... Second code error detection code (EDC), 21 ... First code error detection code
(EDC), 22 ... Parity C1, 23 ... Parity C2,
30 ... Reproduced signal, 31 ... Digital demodulation section, 32 ... Synchronization signal extraction section, 33 ... First code error detection section, 34 ... Code error correction section, 35 ... Second code error detection section, 36 ... Selector.

Claims (3)

[Claims] 1. A first code error detection code adding unit checks whether or not there is a code error in subheader data representing an attribute of main data such as a video signal or a music signal, and the main data and the subheader data are checked as a first code error detection code addition section. 1 time division multiplexing unit performs multiplexing, and a code error correction parity addition unit for the main data, sub header data, and code error detection code of this sub header data is arithmetically added with Whether or not there is a code error in the header data that represents the physical position is checked by the second code error detection code addition section, and the PLL clock pull-in data VFO and the beginning of the sector for facilitating the reading of the header data are detected. A synchronization signal indicating the start of the data portion of the sector, data after the addition of the code error correction parity, and a second And a header data with a code error detection code are multiplexed by a second time division multiplexing unit, and a recording signal modulated by a digital modulation unit is output, and an optical disk recording method. 2. A digital demodulation unit for reproducing digital data such as a video signal or a music signal, sub-header data representing the attribute thereof, and a reproduction signal of the header data representing the physical position of the optical disc in which these data are written. The data is demodulated, and the sync signal at the beginning of the sector or the beginning of the data portion of the sector is extracted by the sync signal extraction unit, and the physical position of the disk written after that is based on the sync signal at the beginning of the sector. The first code error detection unit detects a code error in the header data representing the, and the code error correction unit corrects the code error in the main data such as the video signal or the music signal and the sub header data representing the attribute, While outputting as main data, a code error of the subheader data is detected by the second code error detecting unit, and the subheader data before code error correction is detected. A method for reproducing an optical disc, characterized in that one of the data and the sub-header data after code error correction is selected by a selector and output as sub-header data. 3. A rewritable optical disc, sub-header data representing an attribute of main data such as a video signal or a music signal, and a first code error detection code for checking whether or not there is a code error in the sub-header data. The main data, the main data, the sub-header data, and the code error correction parity related to the first code error detection code are rewritten in the data recording section in the sector by a change in the reflectance of light or a change in the direction of magnetization. In order to facilitate the reading of the header data, it is recorded as possible data and the header data representing the physical position of the disc and the presence or absence of a code error in this header data are checked by the second code error detection code. Shows the VFO data for PLL clock acquisition, a sync signal indicating the beginning of the sector, and the beginning of the data part of the sector. An optical disk recording method characterized in that the sync signal is recorded in an unrewritable form by embossing.