JP2001093155A - Disk reproducing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an illegally copied disk from being reproduced. SOLUTION: When a disk is reproduced, a password data recorded in a read-in area of the disk is read and collated with a password data to be preset on a reproducing device side. Then, if both password data agree with each other, a status of a normal disk detection is transmitted, otherwise, a status of an illegal disk detection is transmitted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a disk reproducing method for reading information stored in a disk medium.

[0002]

2. Description of the Related Art As a read-only memory (ROM), C
A CD-ROM system using D reads reflected light from a recording surface of a disk, generates data in a predetermined format from a change in the reflected light, and supplies the data to a host computer. This CD-R
The OM data format is an extension of the data format of a conventional audio disc, and is a universal standard like the audio disc.

FIG. 4 is a diagram showing a data format of a CD-ROM, and shows a relationship between an EFM signal read from a disk and CD-ROM data generated from the EFM signal. The signal read from the disk becomes an EFM signal through a waveform shaping circuit. This EFM signal is composed of 588 bits as one frame, the first 24 bits of each frame are assigned to a synchronization signal, and thereafter, 1 is repeated with 3 connection bits in between.
Four bits are assigned to data bits.

[0004] The EFM signal is EFM demodulated in units of one frame, and each data bit is converted from 14 bits to 8 bits. This EFM (Ei ght to Fourteen Modulatio
n) is a modulation method in which 8-bit data is converted to 14-bit data and recorded on a disc. When data is written, modulation is performed from 8 bits to 14 bits, and when data is reproduced, 14 bits is converted to 8 bits. Demodulation into bits is performed. According to the EFM demodulation, 8-bit subcode data is obtained from the first data bit following the synchronization signal, and 8-bit × 32-byte data is obtained from the remaining data bits. Then, for this 32-byte data, CIRC (Cross-Interleave Reed-Solomon Code) is used.
An error correction process called “composite” is performed, and finally, 8 bits × 24 bytes of CD-ROM data are generated.

[0005] CD-R in which one frame consists of 24 bytes
In the OM data, 24 bytes × 98 frames (2352 bytes) are handled as one sector. As shown in FIG. 5, one sector includes a synchronization signal (12 bytes), a header (4 bytes), user data (2048 bytes), an error detection code (EDC: Error Detection Code) (4 bytes), and an error correction code. Code (ECC: Error Correction Code) (276
Bytes). In the case of CD-ROM data, scramble processing is performed on 2340 bytes excluding 12 bytes of a synchronization signal in data of one sector, and data is reproduced by performing descrambling processing during reproduction.

[0006]

As the adoption of CD-ROM systems in consumer devices, as typified by electronic books and video games, expands, development of various software corresponding to CD-ROM systems has been developed. Is being promoted. This software has now been generally sold as a CD-ROM disc. In such a situation, a case in which data is read from a commercially available disk, the data is written to another new disk, and the disk is duplicated, has become conspicuous.
However, in the current CD-ROM system, a duplicated unauthorized disk is not distinguished from a legitimate disk, so that any disk is played back in the same manner, and even if the disk is unauthorized, there is a problem in playing the disk. There is no.

Accordingly, an object of the present invention is to discriminate an unauthorized disk from an authorized disk and to enable reproduction only in the case of an authorized disk.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is characterized in that information is recorded from a disk medium having a lead-in area, a program area and a lead-out area. A first step of reading data from a lead-in area of the disk medium, a pre-gap area or a lead-out area following the lead-in area, and reading data from a program area of the disk medium. A second step, a third step of determining whether the information indicated by the data read in the first step matches the preset information, and a status according to the determination result of the third step. And a fourth step that occurs.

According to the present invention, the password data recorded in the lead-in area or the lead-out area of the disk medium is read, and the password data is collated with the password data set in advance, so that the disk medium can be authenticated. It is possible to determine whether or not there is.

[0010]

FIG. 2 is a block diagram showing a configuration of a CD-ROM reproducing apparatus for realizing a disk reproducing method according to the present invention.

The compact disk 1 has a reflecting surface for reflecting a laser beam from the player unit 2, and pits corresponding to digital data are formed on the reflecting surface. In the disk 1, password data is recorded in a specific sector in the innermost lead-in area.
The player unit 2 takes in the reflected light from the disk 1 and reads data recorded on the disk 1 from a change in the reflected light. The read data is subjected to waveform shaping and E
The signal becomes an FM signal, and further undergoes EFM demodulation and CIRC decoding processing, and is converted into CD-ROM data every frame as CD-ROM data.
It is supplied to the D-ROM decoder 3.

The CD-ROM decoder 3 first descrambles 2340 bytes of the 1-frame (2352 bytes) CD-ROM data excluding the synchronization signal, and returns the data returned to a predetermined order. The data is temporarily stored in the buffer RAM 4. Then, based on the error correction information (EDC, ECC) included in each frame, the data stored in the buffer RAM 4 is read out each time, corrected, and stored in the buffer RAM 4 again. The host interface 5 reads out data requested by the host computer from the buffer RAM 4 and outputs the data in response to an instruction from the host computer. The control microcomputer 6 gives an operation instruction to the player unit 2 according to a built-in operation program, fetches a part of the data read by the player unit 2, and according to the data and the operation program, the CD-ROM decoder 3 and the host computer. The operation timing of the interface 5 is controlled.

A feature of the present invention is that, at the start of operation, the control microcomputer 6 issues an instruction to the player unit 2 to access a specific area of the disc 1, and the data read from the area and the preset data Is to be collated. That is, the player unit 2 accesses an area that is not accessed in a normal state, for example, a specific sector in the lead-in area.
To read the password data recorded in the specific sector. Then, by comparing the password data with the data set in the control microcomputer 6, it is possible to determine whether or not the disk 1 is an authorized disk.

In the case of a general CD-ROM system, an operation for reading a sub-code in a lead-in area is possible as in the case of a TOC read which will be described later, but it is set so that data is read from a specific sector in the lead-in area. It has not been. Therefore, the control microcomputer 6 is set to give an operation instruction to read the data in the lead-in area to the player unit 2 so that the password data recorded in the lead-in area can be read.
Normally, no valid data is recorded in this lead-in area, and there is no inconvenience in recording password data.

FIG. 2 is a flowchart showing a disk reproducing method according to the present invention.

When the power is turned on, the first step S
In step 1, it is detected whether or not a disk is loaded in the player unit 2. If no disk is loaded, the process returns to disk detection again. If a disk is loaded, the process proceeds to the next step S2.

In step S2, the TOC (Table of Content) is read from the lead-in area at the innermost periphery of the disc.
Read s). The TOC is a table of contents of data recorded on the disc, and data of a predetermined format is repeatedly recorded in the lead-in area as a subcode.

In the following step S3, it is determined whether or not the disc mounted on the player unit 2 is an audio disc. If it is determined in step S3 that the disc is an audio disc, the flow advances to step S10 to transmit an audio disc detection status and complete the operation. The determination as to whether or not the disc is an audio disc is made based on four bits of control constituted by the Q channel of the subcode data. on the other hand,
If it is determined that the disc is not an audio disc, the process proceeds to step S4, and seek of a specific sector in the lead-in area where the password data is to be recorded is started. In step S6, it is determined whether the seek of the specific sector in the lead-in area is completed. When the seek is completed, in step S6, the data of the specific sector is read, and the password is reproduced from the data.

In step S7, the password read from the disk is compared with a preset password. If the passwords match each other, the flow advances to step S8 to transmit the status of detection of an authorized disk and complete the operation. I do. If the passwords do not match, the process proceeds to step S9, where the status of unauthorized disk detection is transmitted, and the operation is completed.

The various statuses obtained by the above operation steps are not only transferred from the host interface 5 to the host computer side but also used as operation control information of the player unit 2, the CD-ROM decoder 3 and the host interface 5. . For example, the output of data from the player unit 2 or the CD-ROM decoder 3 is stopped in response to the status of detection of an unauthorized disk. As a result, an unauthorized disk in which predetermined password data is not recorded in the lead-in area cannot be reproduced by the CD-ROM reproducing device.

In this embodiment, the password data is recorded in the specific sector of the lead-in area. However, in addition, the pre-gap area following this lead-in area or the lead on the outermost circumference of the disk is used. It may be recorded in the out area. That is, normal data is recorded in the program area between the innermost lead-in area and the outermost lead-out area of the disk 1 as shown in FIG. It becomes possible to record password data in the in-area A and the lead-out area B. In the pre-gap area C set at the beginning of the first track following the lead-in area even in the program area, access for reading data is often not performed, so that the lead-in area A and the lead-out area B Similarly to the above, it can be a recording area for password data.

[0022]

According to the present invention, it is possible to discriminate a copied unauthorized disc, and if the disc is reproduced based on the discrimination, reproduction of the unauthorized disc can be prohibited.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a disk reproducing method according to the present invention.

FIG. 2 shows a CD-R for realizing the disc reproducing method of the present invention.
FIG. 3 is a block diagram illustrating a configuration of an OM playback device.

FIG. 3 is a diagram showing a recording state of data inside a compact disc.

FIG. 4 is a diagram showing a relationship between an EFM signal and CD-ROM data.

FIG. 5 is a diagram showing a format of CD-ROM data of one sector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compact disk 2 Player unit 3 CD-ROM decoder 4 Buffer RAM 5 Host interface 6 Control microcomputer

Claims (2)

[Claims] 1. A disk reproducing method for reading information from a disk medium having a lead-in area, a program area, and a lead-out area, comprising: a lead-in area of the disk medium; a pre-gap area following the lead-in area; First to read data from area
A second step of reading data from the program area of the disk medium, and a third step of determining whether the information indicated by the data read in the first step matches preset information. A fourth step of generating a status according to the result of the determination in the third step. 2. The disk reproducing method according to claim 1, wherein the read operation of the second step is permitted in response to a status of the fourth step.