JPH07169187A - Cd-rom reproducing device - Google Patents

Abstract

PURPOSE:To inhibit reproducing of an unauthorized disk by making a duplicated unauthorized disk possible to be diseriminated and reproducing it based on the discrimination. CONSTITUTION:Password data are recorded in one sector of the innermost circumferential read-in area of a disk 1. A player one 2 reads out data from the disk 1 to send data to a CD-ROM decoder 3 for every frame through waveform shaping an EFM modulation and CIRC decoding. To a byte from which a synchronizing signal is eliminated, a descrambling processing is applied to be stored in a RAM 4 and then is read out from the RAM 4 based on error correcting information to be corrected, and stored in the RAM 4 again. An interface 5 reads out data requested by a main computer from the RAM 4. A microcomputer 6 instructs the player unit 2 to operate and fetches data parts and controls operation timming of the decoder 3 and the interface 5. By such a constitution, the password data are read out to be collated with password data set in a control part and discriminated and then an output other than normal output is stopped to make the reproducing impossible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CD-ROM reproducing device for reading information stored on a compact disc (CD) and supplying it to a host computer.

[0002]

BACKGROUND OF THE INVENTION In a CD-ROM system using a CD as a read-only memory (ROM), the reflected light from the recording surface of the disk is read, and data according to a predetermined format is generated from the change in the reflected light. Configured to supply to a host computer. This C
The data format of the D-ROM is an extension of the data format of the conventional audio disc, and like the audio disc, is a universal standard in the world.

FIG. 4 is a diagram showing a data format of a CD-ROM, and shows a relationship between an EFM signal read from a disc 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 then repeated with a connection bit of 3 bits interposed therebetween.
4 bits are assigned to data bits. The EFM signal is EFM demodulated on a frame-by-frame basis and each data bit is converted from 14 bits to 8 bits. This EFM (E
Right to Fourteen Modulation) is a modulation method in which 8-bit data is converted to 14-bit data and recorded on the disc. When writing data, modulation is performed from 8 bits to 14 bits, and when reproducing data, 14-bit data is used. Demodulation from bits to 8 bits is done. According to the EFM demodulation, 8-bit subcode data is obtained from the first data bit following the sync signal, and 8-bit × 32-byte data is obtained from the remaining data bits. Then, for this 32-byte data, CIRC (Cross-Interle
ave Reed-Solomon Code) error-correction process called composite, and finally CD-ROM of 8 bits x 24 bytes
Data is generated.

CD-R in which one frame consists of 24 bytes
In 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 error correction. Code (ECC: Error Correction Code) (276
Bytes) respectively. In the case of CD-ROM data, 2340 bytes excluding the 12 bytes of the sync signal in the data of 1 sector are scrambled, and the data are reproduced by descrambling at the time of reproduction.

[0005]

With the widespread adoption of CD-ROM systems in consumer devices, as represented by electronic books and video games, development of various software compatible with CD-ROM systems. Is being promoted. This software is now on the market as a disk for CD-ROM. In such a situation, it is becoming conspicuous that the disc is copied by reading the data from the commercially available disc and writing the data to another new disc.
However, in the current CD-ROM system, since duplicated illegal discs and legitimate discs are not distinguished, they are reproduced in the same manner as any disc, and even illegal discs may cause trouble in disc reproduction. There is no.

Therefore, an object of the present invention is to provide a CD-ROM reproducing device which discriminates between an illegal disc and a regular disc and can reproduce only when the disc is a regular disc.

[0007]

The present invention has been made to solve the above-mentioned problems, and is characterized by reading information recorded on an optical disk medium,
A disc player section for generating data having a first format, a decoder section for receiving data output from the disc player section, converting the data into data having a second format, and outputting the data, the disc player section, and the above A CD-ROM reproducing apparatus comprising: a control unit for controlling the operation of a decoder unit, wherein the control unit includes a pre-gap region following the lead-in region of the disc medium in the disc player unit, Or give an instruction to read data from the lead-out area,
It is to determine whether the information represented by the data read in response to this instruction matches the information held in advance, and generate a signal according to this determination result.

Further, the control section gives the disc player section an instruction to read data from the lead-in area or the lead-out area following the lead-in area of the disc medium in response to the instruction. It is determined whether or not the information represented by the data read as described above matches the information held in advance, and in response to the determination result, the output of the data from the disc player unit,
Alternatively, the output of data from the decoding unit may be stopped.

[0009]

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 the control unit in advance, so that the disk medium can be properly authenticated A determination is made as to whether or not The output of data is stopped except when the disc medium is determined to be legitimate, so that the disc medium other than the legitimate disc medium cannot be reproduced.

[0010]

1 is a block diagram showing the structure of a CD-ROM reproducing apparatus according to the present invention. Compact disc 1
It has a reflecting surface that reflects the laser light from the player unit 2, and pits corresponding to digital data are formed on this reflecting surface. On the disk 1, password data is recorded in a specific one sector of the innermost lead-in area. The player unit 2 takes in the reflected light from the disc 1 and reads the data recorded on the disc 1 from the change in the reflected light. The read data is waveform-shaped into an EFM signal, which is further subjected to EFM demodulation, C
After the IRC decoding process, it is supplied to the CD-ROM decoder 3 as CD-ROM data for each frame. CD
The ROM decoder 3 first removes the sync signal from the CD-ROM data of one frame (2352 bytes).
The descrambling process is performed on 340 bytes, and the data returned in a predetermined order 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 and corrected each time, and stored again in the buffer RAM 4. Host interface 5
Responds to an instruction from the host computer, reads out the data requested by the host computer from the buffer RAM 4, and outputs it. Then, the control microcomputer 6 gives an operation instruction to the player unit 2 according to a built-in operation program, takes in 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. The operation timing of the interface 5 is controlled.

A feature of the present invention is that the control microcomputer 6 issues an instruction to access a specific area of the disk 1 to the player unit 2 at the stage of starting the operation, and the data read from the area and the preset data are set. Is to be checked. That is, the player unit 2 is instructed to access a specific sector of the lead-in area, which is not accessed in the normal state, and the password data recorded in the specific sector is read. 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 a proper one.

In the case of a general CD-ROM system, an operation for reading a subcode in the lead-in area is possible like the TOC read described later, but it is set to read data 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 for reading 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, valid data is not recorded in this lead-in area, and there is no inconvenience in recording password data.

The above-mentioned determination operation is performed by the control microcomputer 6, and the operation steps are as shown in the flowchart of FIG. When the power is turned on, the first step detects whether or not a disc is loaded in the player unit 2. If no disc is loaded, the process returns to disc detection again, and if a disc is loaded, the process proceeds to the next step. In the next step, the TOC (Table of Contents) from the lead-in area in the innermost part of the disc
read s). The TOC corresponds to the table of contents of the data recorded on the disc, and data of a predetermined format is repeatedly recorded as a subcode in the lead-in area. When this TOC read is completed, it is determined whether or not it is an audio disc, and if it is determined as an audio disc, the status of audio disc detection is transmitted to complete the operation. Whether or not this is an audio disc is determined by subcode data Q
It is performed by 4 bits of control configured by channels. On the other hand, if it is determined that the disc is not an audio disc, the process proceeds to the next step, and seek of a specific sector of the lead-in area in which password data is recorded is started. When this seek is completed, the data in the specific sector is read and the password is reproduced from the data. Then, in the next step, the password read from the disc is collated with the preset password, and if the passwords match each other, the regular disc detection status is transmitted and the operation is completed. If the passwords do not match, the status of unauthorized disk detection is sent to complete the operation.

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

In this embodiment, the password data is recorded in a specific sector of the lead-in area. However, in addition to this, the pre-gap area following the lead-in area or the lead in the outermost periphery of the disc is read. It may be recorded in the out area. That is, since the normal data is recorded in the program area between the innermost lead-in area and the outermost lead-out area of the disc 1 as shown in FIG. It becomes possible to record password data in the in-area A and the lead-out area B. Also in the program area, the pre-gap area C set at the beginning of the first track following the lead-in area is often not accessed for reading data, and therefore the lead-in area A and the lead-out area B are not accessed. Similarly to, it can be used as a recording area for password data.

[0016]

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

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a CD-ROM reproducing device of the present invention.

FIG. 2 is a flowchart showing an operation of the CD-ROM reproducing device of FIG.

FIG. 3 is a diagram showing a data recording state 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 1-sector CD-ROM data.

[Explanation of symbols]

 1 compact disc 2 player unit 3 CD-ROM decoder 4 buffer RAM 5 host interface 6 control microcomputer

Claims (2)

[Claims] 1. A disc player section for reading information recorded on an optical disc medium and generating data having a first format, and a data format outputted from the disc player section, having a second format. A CD-ROM reproducing device comprising a decoder section for converting to data and outputting the data, and a control section for controlling the operations of the disc player section and the decoder section, wherein the control section is provided in the disc player section. Information in which an instruction to read data from a lead-in area of the disc medium, a pre-gap area following the lead-in area, or a lead-out area is given, and information represented by data read in response to the instruction is held in advance CD- characterized by generating a status according to the result of the determination. ROM playback device. 2. A disc player section which reads information recorded on an optical disc medium and generates data having a first format, and a data which is output from the disc player section and has a second format. A CD-ROM reproducing device comprising a decoder section for converting to data and outputting the data, and a control section for controlling the operations of the disc player section and the decoder section, wherein the control section is provided in the disc player section. Information in which an instruction to read data from a lead-in area of the disc medium, a pre-gap area following the lead-in area, or a lead-out area is given, and information represented by data read in response to the instruction is held in advance Data is output from the disc player section in response to the determination result. Or a CD-ROM characterized by stopping the output of data from the decoding section
Playback device.