KR100226822B1 - Method for varying record speed according to kind of disc - 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

The present invention relates to the control of the recording speed of a rewritable compact disc (CD-R), and in particular, finds an appropriate speed that can be recorded on a disc, and varies the recording speed according to the type of disc for recording data on the disc without damaging the data. It is about a method.

In general, a CD-R system is a system capable of recording data once by a laser on a disc.

That is, data is recorded by changing the chemical substance adjusted 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 recorded data is recorded. In Area), a Program Memory Area (PMA) containing information about the data being recorded, and a Power Calibration Area (PCA) to determine 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, recording is not possible anymore even though 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 each recording power is Hi-Fi (HF) as shown in the waveforms of FIGS. 3A to 3C. ), The power of (A1 + A2) / (A1-A2) becomes '0'.

That is, FIG. 3A illustrates a case where 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 with the disc proper power Po. 3C shows 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 value of (A1 + A2) / (A1-A2) becomes '0'.

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.

Current CD-R discs can be divided into halo platinum cyanine and cyanine.

At both recording speeds of about 2x speed, the recording power is close to the value of 3T-11T. However, in the case of cyanine discs, the proper recording power of 3T is rapidly increased when the recording speed is more than 4 times as shown in FIG. 4B. can see.

However, the Pthalo cyanine-based disc can be seen that the recording power has a value close to that of the 3T-11T value even when the recording speed is four times higher than that shown 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. 4B can record 3T and 11T when the data is recorded at 4x or higher speed. 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 determining the disc type by reading and recording data in the double speed test section of the PCA area using the optimum recording power obtained in the second step if the recording double speed is set to a high double speed by the user; The recording speed set by the user according to the type of the disc determined in the third step is predetermined speed. To adjust the recording speed and then record and read the data in the test section again at the adjusted recording speed to obtain the optimal recording power, and to record the data to the disc with the optimal recording power obtained in the fourth stage. The fifth step is to include.

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

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

3A to 3C are waveform diagrams showing hi-fi signals for respective recording powers.

4a is a graph showing the relationship between the recording power and the 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-based disk.

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

6 is a waveform diagram showing reflectance by 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 the reflection detection unit of FIG.

9 is a diagram showing the relationship between the pit and the amount of reflection

10A to 10C show another embodiment for determining the disc type in the method of varying the recording speed according to the disc type of the present invention.

Explanation of symbols for main parts of the drawings

70 disc 71 light detector

72: reflection amount 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.

That is, by dividing the data into 15 steps centering on the reference laser power recorded on the disc, random data or constant values are recorded in the test section of the test area, and then irradiated with HF signals for each recording power (A1 + A2) / (A1-A2). The recording power of about 0.04 is obtained.

At this time, since the optimum 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 double 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 value for recording 3T is most severe, 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, the accurate pit of 3T is not formed when the reproducing laser is irradiated. .

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 the power at 4 times the speed, so that the recording power is weak, so that the pit is not properly formed and the amount of reflection in the pit formed portion and the pitless portion is large. 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 view 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 reflection amount is very small as shown in FIG. 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, by switching the laser to the regenerative power and examining the newly created double speed test section, it is possible to recognize that the amount of reflection in the pit-formed portion and the non-formed portion is remarkably different as shown in FIG. 6A.

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

The laser diode (LD) power control unit 74 ignores the recording speed set by the user and controls the power of the LD 75 at the recording 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, an appropriate recording speed is set to record the data, thereby increasing the reliability of the recording data.

On the other hand, Fig. 10 is another 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 the 3T recording wave and the 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 minus axis rather than the normal 11T output waveform as 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 minus axis rather 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. If the disc type is discerned by the test in the double speed test section, and the disc type is determined as cyanine, the data is recorded at the maximum recording speed suitable for the disc characteristics regardless of the recording speed set by the user. Recordable, which increases the reliability of recorded data.

Claims (6)

The first step of dividing the test area of the power adjustment area (PCA) of the disc into a test section and a double speed test section, and recording power in several stages centering on the reference laser power recorded on the disk before recording when recording the data of the disk. The second step of obtaining the optimum recording power by dividing the predetermined data in the test section and reading it out and irradiating the hi-fi (HF) signal for each recording power, and in the second step if the recording speed is set to high speed by the user The third step of determining the disc type by reading and recording data in the double speed test section of the PCA area using the obtained optimal recording power, and the recording speed set by the user according to the disc type determined in the third step. Adjust the recording speed by lowering the speed to a predetermined speed, and then adjust the recording speed again to the test interval. And a fifth step of obtaining an optimum recording power by recording and reading out the other, and a fifth step of recording data on the disk at the optimum recording power obtained in the fourth step. Variable speed method. 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 pit is formed and the portion that is not formed. 4. The method of claim 3, wherein the third step comprises amplifying the reproduction signal detected in the portion where the pits are formed and the portion not formed, and then comparing the difference between the high level and the low level of the amplified signal to determine the disc type. The recording speed variable method according to the type of disc. The method of claim 1, wherein the third step comprises recording 3T data and 11T data at 11T recording power and then comparing the hi-fi signals of the two data to determine a disc type. The method of claim 1, wherein the third step is performed by recording 3T data and 11T data at 3T recording power, and then comparing the hi-fi signals of the two data to determine a disc type.