KR0159291B1 - Optical disc discriminating method - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc discrimination apparatus in a recordable optical disc system, and more particularly, to a disc type discrimination method for accurately determining a disc type so as to prevent damage to a disc due to a user error.

In a recordable optical disc player system, a PMA area and a lead-in area of a disc are picked up to accurately determine the type of disc according to whether data is recorded or not, thereby preventing damage to the disc due to a user error.

Description

How to determine the type of optical disc

1 is a subcode block diagram.

2 is a configuration diagram of a compact disc player system according to the present invention.

3 is a flow chart according to the present invention.

4 is a layout structure diagram of a compact disc according to a data recording state.

5 is a waveform diagram for determining the presence or absence of recording data according to the present invention.

* Explanation of symbols for main parts of the drawings

10: optical disc 12: pickup device

14: RF amplifier 16: signal processor

18: frame synchronization detector 20: phase detector

22: microcomputer 24: low pass filter

26: motor drive part 28: spindle motor

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc discrimination apparatus in a recordable optical disc system, and more particularly, to a disc type discrimination method for accurately determining a disc type so as to prevent damage to a disc due to a user error.

Normally, a compact disc player can detect 8-bit subcodes recorded on a disc and automatically play back the recorded songs in a predetermined order.

The subcode is recorded on the disc as 8 bits of data per frame, and 1 bit of each P, Q, R, S, T, U, V, W channel is recorded. .

The two bits of the P and Q channels are used for the purpose of having a program function for reproducing songs in the beginning or in a newly set order. In addition, the 6 bits of the R, S, T, U, V, and W channels are used for the purpose of enabling various fun methods that have been impossible in analogue LP (Long Play).

On the other hand, as shown in FIG. 1A, the subcodes constitute one block with 98 x 8 = 784 bits recorded in 98 frames. In the subcodes shown in FIG. 1A, the 98-bit Q channel is configured as shown in FIG.

That is, two bits S0 and S1 are the sub-coating synchronization signals and have the following pattern.

The S0 = 00100000000001 and S1 = 00000000010010 controls display 4 bits, which indicates the number of audio channels and the presence or absence of emphasis.

The address is represented by 4 bits, and there are three cases. Mode 1 → 0001, Mode 2 → 0010, Mode 3 → 0011, and is generally coded as Mode 1. In addition, the contents of the data vary depending on the address. Cyclic Redundancy Code (CRC) is an error detection code and is given 16 bits.

When the address is encoded in mode 1, the contents of the data in FIG. 1 (b) are configured as in FIG.

That is, the first 8-bit TNO indicates how many songs are used as the song number, and it is represented by a 2-digit binary decimal number and the maximum value that can be expressed is 99.

In addition, if the TNO is 0, the lead number tracks 00-99 are song numbers, and if AA, the lead out track is displayed.

An 8-bit index is used when further dividing one song indicated as 8 bits in the TNO and can also divide one song up to 99. The index is zero in the pause time region between the tune and the tune.

In each 8-bit Rmin, Rsec, and R frame, the number of minutes, seconds, and number of frames is represented by two digit binary numbers. That is, Rain, Rsec, R frame starts at 0.

The next 8 bits are fixed at zero.

Each 8-bit Amin, Asec, and A frame is the absolute time code of one disc, indicating how many minutes, seconds, and frames the recorded songs of the entire disc are, so 0 is the inside of the disc. It is a song where music begins as a circumference.

The 24-bit content containing the time code as a cumulative time in the lead-in area is recorded with the index of the corresponding disk called TOC (Table Of Contents).

The CDP can read the contents of the TOC for the first time and operate the Pick Up using the detailed time code given to the Q channel.

In general, to find the desired song, calculate the difference of Amin corresponding to the target TNO, and then do a large amount of TrackJump at first according to the result, and then do a small amount of track jumping as it approaches the target TNO. Find the target TNO.

The compact disc player reproduced as described above is used only for reproduction, but recently, a compact disc player capable of recording has been developed due to the rapid development of data recording technology using semiconductor technology and laser light. Therefore, in a recordable compact disc player, when a user incorrectly judges a play-only disc as a recordable CD-WO disc and performs a recording operation, there is a problem that the disc is damaged.

Accordingly, an object of the present invention is to provide a disc type determination method for automatically and accurately determining the type of a disc inserted in a deck in a compact disc player system.

SUMMARY OF THE INVENTION An object of the present invention is to provide a disc type discrimination method for accurately determining the type of a disc inserted in a deck in a compact disc player system to prevent damage to the disc due to a user error.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of a compact disc player system according to the present invention.

A pickup device 12 for picking up and outputting recording information from the disk 10, an RF amplifier 14 for RF amplifying the output of the pickup device 12, and an output of the RF amplifier 14 are subjected to EFM (Eight). a signal processor 16 for shaping, demodulating and outputting a waveform to the fourteen modulation; a frame sync detector 18 for inputting an EFM waveform shaped signal from the signal processor 16 to detect a frame sync signal;

A phase detector 20 for detecting a phase difference by inputting a synchronization signal detected by the frame synchronization detector 18 and comparing it with a reference clock (7.35 KHz), and receiving a phase difference signal detected by the phase detector 20 to provide a disc type. A microcomputer 22 for determining

A low pass filter 24 for low-pass filtering the phase difference signal detected by the phase detector 20;

A motor driver 26 driving the spindle motor 28 for rotating the disc 10 by inputting the low pass filtered signal of the low pass filter 24;

A servo unit 30 for inputting an output of the RF amplifier 14 and an EFM waveform shaped signal of the signal processor 16 to output tracking, focusing, and sled servo signals;

A sled motor driver 32 for driving a sled motor of the pickup device 12 by inputting a sled servo output signal of the servo unit 30, and tracking and focusing servo signals of the servo unit 30. And an actuator driver 34 that inputs and drives the tracking and focusing actuator of the pickup device 12.

3 is a flowchart according to the present invention,

Moving the optical pickup to the program memory area (PMA) area of the compact disc to detect the presence or absence of data in the PMA area, and when there is data recorded in the PMA area in the process of detecting data presence in the PMA area moving the optical pickup to a lead-in area to determine a partially recorded CD-WO disc and all recorded CD-WO discs according to the presence or absence of data in the lead-in area, and detecting the presence or absence of data in the PMA area If there is no data in the PMA area, the optical pickup is moved to the lead-in area of the compact disc to determine the CD-WO blank disc and the playback-only disc according to the data of the lead-in area.

4 is a layout structure diagram of a compact disc according to a data recording state.

FIG. 4A is a blank disk layout structure diagram, FIG. 4B is a partially recorded disk layout structure diagram, and FIG. 4C is a fully recorded disk layout structure diagram.

5 is a waveform diagram for determining the presence or absence of recording data according to the present invention.

Based on the above-described configuration, an embodiment of the present invention will be described in detail with reference to FIGS.

Compact disc types include a play-only disc and a recordable CD-WO (CD-WO). Here, the recordable CD-WO is recorded in the form of a partially recorded disc as shown in FIG. 4 (4b) and a full recorded disc as shown in FIG. 4 (4c) and as shown in FIG. 4 (4a). Are not classified as blank discs.

At this time, the recordable CD-WO has a PMA area and the playback-only disc does not have a PMA area.

Here, the PMA area is an area for temporarily storing information about the recorded song every time additional recording is performed before completion of recording, and the configuration is the same as the Q code described in FIG.

To accurately determine the type of disc among the various discs as described above, the PMA area and the lead-in area of the disc are picked up to detect the presence of data. The presence or absence of data in the PMA area and the lead-in area is determined by the following operation.

When the information recorded in the PMA area or the lead-in area of the disk 10 is picked up by the pickup device 12 and outputted, the RF amplifier 14 amplifies and outputs the output of the pickup device 12. The RF-amplified signal is input to the signal processor 16 to form an EFM waveform in the signal processor 16 and then output a demodulation process. The frame synchronization detector 18, which inputs the EFM waveform shaped signal from the signal processor 16, detects the synchronization signal and outputs the synchronization signal to the phase detector 20. As a result, the phase detector 20 compares the detected synchronization signal with a reference clock signal (7.35 KHz) as shown in FIG. 5A to detect a phase difference.

At this time, if the synchronization signal of the fifth frame 5b is detected by the frame synchronization detector 18, the phase detector 20 detects the phase difference signal of FIG. 5c. If the phase detection unit 20 detects a phase difference signal, no data is recorded in the picked-up area. If the phase difference signal is not detected, data is recorded in the picked-up area.

Therefore, the microcomputer 22 detects the phase difference detection signal of the phase difference detection unit 20 to determine the type of disc.

Therefore, the operation for determining the type of disk according to the present invention will be described with reference to the flowchart of FIG.

First, in step (3a), the pickup device 12 is driven to move the optical pickup to the innermost PMA area of the disk 10, and in step 3b, the spindle motor 28 has a frame synchronization pattern of the reference clock (7.35 KHz). Drive to turn on CLV (hereinafter referred to as CLV) and perform step (3c). In step (3c), the PMA area of the disc 10 is picked up to check whether data is recorded.

That is, if the phase difference signal is detected by the phase difference detecting unit 20 and the phase difference signal is detected, data is not recorded in the PMA area. If the phase difference signal is not detected, the data is recorded in the PMA area.

Therefore, if data is recorded in the PMA area (3d) in step (3c), if data is not recorded in the PMA area (3i).

In step (3d), the optical pickup of the pickup device 12 is moved to the lead-in area by recognizing the partially recorded CD-WO and the all-recorded CD-WO (step 3e). In the step (3e), the spindle motor 28 is driven by the frame synchronization pattern of the reference clock (7.35KHz) to turn on the sieve (3f).

In step (3f), the lead-in area of the CD-WO recognized in step (3d) is picked up, and the data is recorded. If it is determined as WO and the lead-in area is not recorded with data, it is judged as a partially recorded CD-WO in step (3h).

On the other hand, in step (3i), the optical pickup of the pickup device 12 is moved to the lead-in area by recognizing it as a recordable blank CD-WO or a compact disc for reproduction only, and step (3j) is performed.

In step (3j), the CLV is turned on by driving the spindle motor 28 in a frame synchronization pattern of the reference clock (7.35 KHz), and step (3k) is performed. In step (3k), the lead-in area of the disc recognized in step (3i) is picked up to check whether data is recorded. If data is recorded in the lead-in area, it is determined as a compact disc for playback only in step (3m). If no data is recorded in the lead-in area, it is determined as blank CD-WO in step (3l).

In the optical disc player system capable of recording as described above, the PMA area and the lead-in area of the disc are picked up to accurately determine the type of disc according to whether data is recorded or not, thereby preventing damage to the disc due to a user error. There is an advantage.

Claims (5)

A disc type discrimination method of a recordable optical disc player system, comprising: moving an optical pickup to a compact disc's PMA area to enable or disable data recording, and a lead-in area of a compact disc when there is data recorded in the PMA area. Moving the optical pickup to determine the type of CD-WO according to the presence or absence of recording data in the lead-in area; and moving the optical pickup to the lead-in area of the compact disc without data recorded in the PMA area. And determining the playback-only compact disc in accordance with the presence or absence of data recorded in the target area. 2. The method of claim 1, wherein the CD-WO type determination process determines whether the CD-WO is recorded when there is recording data in the lead-in area, and when the CD-WO is partially recorded when there is no recording data in the lead-in area. Characterized by the above. The method as claimed in claim 1, wherein when there is recorded data in the lead-in area in the process of determining the reproduction-only compact disc, the method determines the reproduction-only compact disc. The method as claimed in claim 1, characterized in that the blank CD-WO is discriminated when there is recording data in the lead-in area in the reproduction-only compact disc discrimination process. A disc type determination method of a recordable optical disc player system, comprising: detecting the presence or absence of data recorded in a PMA area of a compact disc, and when there is data recorded in the PMA area and recording data in the lead-in area. Discriminating with the recorded CD-WO; discriminating with the partially recorded CD-WO when there is data recorded in the PMA area and no recording data in the lead-in area; and no data recorded in the PMA area. Determining if there is recorded data in the lead-in area by using a playback compact disc; and determining by blank CD-WO when there is no data recorded in the PMA area and no data recorded in the lead-in area. How to feature.