KR19980059940A - Variable recording speed according to disc type - Google Patents

Abstract

The present invention relates to a method of controlling the recording speed of a rewritable compact disc (CD-R). In particular, the optimum recording power is obtained when the recording speed of the disc is set to the high recording speed in the test section of the PCA area during data recording. In the double speed test section, it is checked once more to determine the type of the disc. If the disc type is determined as cyanine, the data is recorded at the maximum recording speed suitable for the characteristics of the disc regardless of the recording speed set by the user. Can be recorded to increase the reliability of the recorded data.

Description

Variable recording speed according to disc type

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to recording speed control of a rewritable compact disc (CD-R). In particular, the recording speed varies depending on the type of disc that records data on the disc without damaging the data by finding an appropriate speed that can be recorded on the disc. It is about a method.

In general, the CR-R system is a system capable of recording data once by a laser on a disk.

In other words, data is recorded by changing the chemical substance formed on the disk with a laser.

Referring to the structure of a CD-R disc, as shown in FIG. 1, a recordable user area in which data is recorded, a program area in which data is recorded, and a lead-in area in which information about the recorded data is recorded. In Area), a Program Memory Area (PMA) with information about the data being recorded, and a Power Calibration Area (PCA) for determining the appropriate laser power for the data to be written. have.

At this time, the CD-R system operates to record an appropriate laser power in the PCA area before recording data.

This PCA region is shown in detail in FIG.

That is, the PCA area is divided into a test area for testing the laser power and a count area for recording the number of tests.

At this time, the test can be performed up to 100 times, which is checked in the count area, and if more than 100 times, no recording is possible even if the recording space remains.

On the disc, an appropriate laser power is recorded on the current disc and tested based on the value.

The test method is divided into 15 steps based on the reference laser power recorded on the disk, and then random data or a constant value is recorded in the test area, and then the Hi-Fi (Hi-Fi; HF) is recorded for each recording power as shown in the waveforms of FIGS. 3A to 3C. ), The value of (A1 + A2) / (A1-A2) becomes '0'.

That is, FIG. 3A illustrates a case in which the power P recorded in the test area is smaller than the disc optimal power Po, and FIG. 3B illustrates precisely matching the power P recorded in the test area and the disc proper power Po. 3C is a case where the power P recorded in the test area is larger than the disc proper power Po.

Therefore, when the power recorded in the test area is the same as in Fig. 3B, the power at which the value of (A1 + A2) / (A1-A2) becomes '0' is obtained.

However, since it is impossible to find a recording power that is exactly zero, the CD-R specification recommends that a recording power of (A1 + A2) / (A1-A2) be about 0.04.

After such laser power adjustment, data is recorded in the recordable user area of FIG.

However, the most suitable laser power for each recording speed is different depending on the chemicals formed on the recordable surface of the disc.

Currently CD-R discs can be divided into halo platinum (Pthalo) cyanine (cyanin) system and cyanine system.

At the recording speed of about 2 times the two disc modes, the recording power has a value close to that of the 3T-11T value. However, in the case of a cyanine disc, as shown in FIG. 4B, when the recording speed is 4 times or more, the proper recording power of 3T is rapidly increased. can see.

However, the Pthalo cyanine-based disc can be seen that the recording power has a value close to 3T-11T even when the recording speed is four times higher than in FIG. 4A.

That is, the Pthalo cyanine-based disk as shown in FIG. 4A can record stable data even if the data is recorded at high speed of 4 times or higher, but the cyanine-based disk as shown in FIG. The difference in the recording power is large and cross points such as point a are generated.

Therefore, this disk cannot stably record data at four times or more speed.

That is, if data is recorded at a 4x speed on a cyanine-based disk capable of recording up to 2x speed, stable data cannot be obtained, resulting in loss of recorded data.

When the disc of cyanine is to be recorded at 4 times speed, it operates as described above by irradiating a constant laser power to the PCA area, but the reflected HF signal is (A1 + A2) / (A1-A2) = 0. Since the data is recorded in the recordable data area with a laser power that cannot record stable data.

As described above, in the conventional CD-R system, data can be unconditionally recorded on the disc at the recording speed set by the user regardless of the recording property of the disc. Therefore, the stability of the recording data cannot be guaranteed and the reliability of the recording data is inferior. There was this.

Disclosure of Invention The present invention has been made to solve the above problems, and an object of the present invention is to determine the type of disc when recording data at high speed, and according to the determination result, the maximum recording speed that matches the characteristics of the disc regardless of the recording speed set by the user. The present invention provides a method of varying the recording speed according to the type of disc, by which data can be recorded so that stable data can be recorded.

According to an aspect of the present invention, there is provided a method of varying a recording speed according to a disc type, comprising: a first step of dividing a test area of a PCA into a test section and a double speed test section; The second step of dividing the recording power into several stages based on the reference laser power previously recorded on the disc, recording predetermined data in the test section, reading the data, and then searching the hi-fi (HF) signal for each recording power to obtain an optimal recording power. And a third step of recording and reading out data in the double speed test section of the PCA area using the optimum recording power obtained in the second step if the recording speed is set to a high speed by the user, and determining the disc type. The recording speed set by the user is reduced to a predetermined speed according to the type of the disc determined in the third step. After adjusting the recording speed, the fourth step of recording and reading the data in the test section again at the adjusted recording speed to obtain the optimal recording power, and recording the data to the disc with the optimal recording power obtained in the fourth stage. It includes the fifth step.

1 is a view showing the structure of a typical CD-R disc

FIG. 2 shows the format of the PCA, PMA, and lead-in areas on the disk of FIG.

3A to 3C are waveform diagrams showing a hi-fi signal for each recording power

4A is a graph showing the relationship between recording power and recording speed of a Pthalo cyanine-based disk

4B is a graph showing the relationship between the recording power and the recording speed of the cyanine disc.

5 is a diagram illustrating a format of a PCA region according to the present invention.

6 is a waveform diagram showing reflectance for each recording power;

7 is a block diagram illustrating a method of changing a recording speed according to a disc type of the present invention.

FIG. 8 is a detailed block diagram of a reflection amount detector of FIG. 7; FIG.

9 is a diagram showing a relationship between a pit and a reflection amount;

10A to 10C illustrate another embodiment for determining a disc type in the variable speed variable method according to the disc type of the present invention.

Explanation of symbols for main parts of the drawings

70: disc 71: light detection unit

72: semi-specific detection unit 73: micom

74: LD power control unit 75: LD

81: amplifier 82: high level detector

83: low level detector 84: subtractor

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

5 is a diagram illustrating a format of a PCA region used in the present invention, which is divided into a test region for testing laser power and a count region for recording the number of tests, wherein the test region is a recording speed test interval and a double speed. It is divided into test intervals.

The speed test section is a reserved area not defined in the CD-R specification. Even if a test value is recorded in this area, the disc does not affect the test area.

That is, when the user sets the recording speed and wants to record data at the set recording speed, the CD-R system finds a recording laser power suitable for the recording speed set in the PCA area.

If 3T data is recorded and reproduced in the test section of the test area, an optimum recording power of (A1 + A2) / (A1-A2) = 0.04 is obtained according to the PCA operation method.

In other words, after dividing the data into 15 stages based on the reference laser power recorded on the disk, random data or a constant value is recorded in the test section of the test area, and then irradiated with HF signals for each recording power (A1 + A2) / (A1-A2). Find a recording power of about 0.04.

At this time, since the optimal recording power is a value that can be guaranteed only at 2 times or less, if the recording speed is set to 4 times or more, the PCA operation is set in the speed test section of the test area of FIG. 5 to increase the reliability of the recording data. One more check is made to see if the recording laser power is adequate.

In order to record the test value in the double speed test section, as shown in FIGS. 4A and 4B, since the laser power recording 3T has the most deviation, 3T data is recorded at 11T power.

Then, since the recording power capable of forming the 3T waveform is different depending on the type of disk, the formation of the 3T waveform on the disk is incorrect.

The fact that 3T formation on the disc is incorrect means that when 3T is formed with the set recording laser power in the cyanine disc, the exact amount of 3T is not formed. When the laser is irradiated, the reflection amount is different from that of exactly 3T. .

6 shows that the amount of reflection varies depending on the formation of pits.

6A shows a case where each pit is formed correctly on the disc.

That is, since the reproduction laser is scattered at the portion where the pit is formed, the amount of reflection is small compared with the portion where the pit is not formed.

Therefore, the difference in the amount of reflection in the portion with and without the pit with respect to the formation shape of the pit recorded on the disk becomes large.

FIG. 6C is a waveform that can be generated when a 3T waveform is radiated to a cyanine disk at 11 times power at 4 times the speed, and the recording power is weak. Therefore, the amount of reflection in the pit formed portion and the pitless portion is large because the recording power is weak. No difference

That is, 3T data is recorded at 11T power in the double speed test section of the disk 70 and then reproduced by the light detector 71 and output to the reflection amount detector 72.

At this time, since the reflection amount output for the pit is extremely small as shown in FIG. 9, the amplifier 81 of the reflection amount detection unit 72 amplifies the reproduction signal to a predetermined level.

Fig. 9 is a general diagram showing the relationship between the pit and the amount of reflection when the reproducing laser passes over the pit formed on the disc. It can be seen that the reflection amount at is a very small value.

On the other hand, the signal Ra amplified by the amplifier 81 is input to the high level detector 82 to detect the high level peak value, and is input to the low level detector 83 to detect the low level peak value.

The subtractor 84 outputs the difference signal Rd between the output signal Rha of the high level detector 82 and the output signal Rla of the low level detector 83 to the microcomputer 73.

The microcomputer 73 uses the output signal Rd of the subtractor 84 to determine the type of disc.

That is, if the pit is not properly formed, the Rd value becomes small. Therefore, if the peak-to-peak value Rd of the amount of reflection is very small as shown in FIG. 6C, the microcomputer 73 selects the currently mounted disk. It is recognized as a cyanine disk.

Therefore, the microcomputer 73 lowers the recording speed set by the user and operates to search for the optimum recording laser power in the test section of the test area of the PCA area to find the optimum recording power.

Then, 3T data is recorded at 11T power in the double speed test section of the PCA region of FIG. 5 to determine whether the newly set optimal recording laser power is suitable at the newly set recording speed.

Then, when the laser is switched to the regenerative power and the newly created double speed test section is examined, it is possible to recognize that the amount of reflection in the pit-formed portion and the non-formed portion is significantly different as shown in FIG. 6A.

Therefore, the microcomputer 73 switches the speed to the recording speed suitable for the optimal recording laser power found by the PCA operation.

The laser diode (LD) power control section 74 ignores the recording double speed set by the user and controls the power of the LD 75 at the recording double speed switched by the control of the microcomputer 73 to record data.

In this way, the type of disc is determined to determine whether the recording speed set by the user is a proper speed, and if it is determined that the speed is not a proper recording speed, a proper recording speed is set to record the data, thereby increasing the reliability of the recording data.

On the other hand, Fig. 10 is a further embodiment of the present invention, in which the type of disc is determined during an operation for finding an appropriate recording power in the PCA area.

That is, when the PCA region is tested at twice the speed of the cyanine-based disk, since the difference between 3T recording power and 11T recording power is not shown in FIG. 4B, the HF signal is output as shown in FIG. 10A, and the difference Dro between the two output waveforms is constant. Will be the value.

In this case, the normal Dro value may be obtained through experiments.

If 11T waveforms are recorded at 3T power at 4 times the speed on a cyanine-based disk, the HF signal for 3T is normally output because the proper recording power for recording 3T is greater than that for recording 11T as shown in FIG. 4B. The HF signal for 11T is obtained with the waveform shifted to the (-) axis rather than the normal 11T output waveform as shown in FIG. 10B.

Therefore, if a 3T waveform is recorded with a recording power for recording 11T, a waveform in which the HF signal for 3T as shown in Fig. 10C is shifted on the (-) axis than the normal 3T output waveform is obtained.

That is, the two signal differences Dr3 and Dr11 in FIGS. 10B and 10C are larger or smaller than Dro in FIG. 10A, which is a normal signal difference.

Therefore, the microcomputer can determine the appropriate recording speed even by detecting this signal difference.

In this case, as described above, if the disc type is determined to be cyanine, the recording speed set by the user is ignored, and the recording speed set by the user is lowered to find the optimum recording laser power in the test section of the test area of the PCA area. To find the optimal recording power and record the data.

As described above, according to the method of varying the recording speed according to the disc type of the present invention, if the optimum recording power is found in the test section of the PCA area during data recording, and the recording speed of the disk is set to the high speed, the optimal recording power is appropriate. In the double speed test section, the disc type is determined again. If the disc type is determined to be cyanine, the data can be recorded at the maximum recording speed suitable for the characteristics of the disc regardless of the recording speed set by the user. Recordable, which increases the reliability of recorded data.

Claims (6)

The recording power is divided into a first step of dividing the test area of the power control area (PCA) of the disc into a test section and a double speed test section, and several steps centering on the reference laser power recorded on the disc before recording when data is written to the disc A second step of obtaining an optimal recording power by recording and reading predetermined data in a test section and examining a hi-fi (HF) signal for each recording power; and if the recording double speed is set to high speed by the user, the second step is obtained. A third step of determining a disc type by recording and reading data in a double speed test section of the PCA area using an optimal recording power; and setting a recording speed set by a user according to the disc type determined in the third step. Adjust the recording speed by lowering to double speed and then record the data in the test section again at the adjusted recording speed. And a fifth step of reading and reading an optimum recording power, and a fifth step of writing data to the disc at the optimal recording power obtained in the fourth step. . The method according to claim 1, wherein the double speed test section of the PCA area is a spare area not defined in the disc specification. 2. The method of claim 1, wherein the third step determines the type of disc by comparing the difference in the amount of reflection between the portion where the pits are formed and the portion that is not formed. 4. The method of claim 3, wherein the third step includes amplifying a reproduction signal detected in a portion having a pit and a portion not formed, and then comparing the difference between the high level and the low level of the amplified signal to determine a disc type. The recording speed variable method according to the type of disc. The method of claim 1, wherein the third step is to record 3T data and 11T data at 11T recording power, and then compare the hi-fi signals of the two data to determine a disc type. The method of claim 1, wherein the third step is to record 3T data and 11T data at 3T recording power and then compare the hi-fi signals of the two data to determine a disc type.