KR20040057373A - Method for constructuring defaut write strategies of an optical disc drive, method for adapting a write strategy and recording media therefor - Google Patents

Abstract

PURPOSE: A method for configuring a default writing strategy of an optical disk drive, a writing strategy applying method using the configuring method, and an appropriate recording media therefor are provided to set a default strategy for an unknown disk based on statistical similarity, thereby efficiently applying a writing strategy as guaranteeing excellent writing performance. CONSTITUTION: A system examines optimal writing strategies for disks where types of manufacturers and writing materials are known(S602). The system examines a distribution of the writing strategies in accordance with the types of the writing materials and writing power(S604). The system selects a writing strategy having the highest distribution according to the types of the writing materials and the writing power(S606). The system writes the selected writing strategy on firmware as a default writing strategy(S608).

Description

A method for constructing defaut write strategies of an optical disc drive, a method for adapting a write strategy and recording media therefor}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optimal recording method of an optical disc, and more particularly, to a method of configuring a default recording strategy for an unknown disc whose type of recording material is unknown, and a method of applying a recording strategy using the same, and a suitable recording medium.

Recording data on an optical disc, which is one of the optical recording media, means forming a mark on a track formed on the optical disc. Currently available optical discs that can be recorded, erased, and played back include 650MB CD-R / RW, 4.7GB DVD-RAM / R / RW, 4.7GB DVD + RW, and HD-DVD with more than 23GB of capacity to come. .

In the case of a recordable disc, a recording layer is coated with a CD-R disc having an organic pigment applied thereto, dissolved by heat of a laser to form a pit, and a phase change film that changes crystalline or amorphous depending on temperature, and the mark has a phase change of the phase change film. There is a CD-RW disc formed through. In the case of such a recordable medium, a technique called a writing strategy is introduced in order to optimize the recording / reproducing characteristic, and the recording strategy is applied differently according to each recording medium described above.

The recording strategy suitable for each disc is examined in advance and recorded on the disc's firmware. When the disc is mounted, the optical disc drive reads ATIP information recorded on the disc to determine the disc manufacturer and the type of recording material, and selects and uses the corresponding recording strategy. If the disk is not recorded on the firmware, the default recording strategy is selected and used. The default recording strategies are set one by one according to the type of recording material.

According to the conventional recording method, the recording strategy is constructed and coped with all types of discs currently supplied as possible, and the counterpart is used by default with the write strategy set to the unknown disc. However, such a conventional recording method cannot efficiently cope with the trend of increasing the number of manufacturers of discs in circulation. As described above, it is experimentally confirmed that there are many variations in the case of applying the recording strategy according to the type of recording material used for the disc.

Therefore, since the conventional recording method of selecting the recording strategy using only the recording material used for the disc cannot secure excellent recording characteristics, it is necessary to establish a recording strategy that considers not only the recording material but also the recording power.

An object of the present invention is to provide a method of configuring an optimal default recording strategy according to the manufacturer of an optical disc, the type of recording medium, and the optimum recording power.

Another object of the present invention is to provide a method of applying a default write strategy suitable for the above-described default write strategy configuration method.

Another object of the present invention is to provide recording media suitable for the above methods.

1 shows each area of a CD-R disc.

2 is a flowchart showing a conventional method of setting a recording strategy using a disc identification symbol.

3 is a waveform diagram showing recording pulses of a CD-R disc.

4 is a graph showing the distribution of recording pulses for each recording optical power of a Cyanine series CD-R disc.

5 is a graph showing the distribution of recording pulses for each recording optical power of a PhthaloCyanine-based CD-R disc.

6 is a flowchart showing a preferred embodiment of the method for configuring a default write strategy according to the present invention.

7 is a flowchart showing a preferred embodiment of the method for applying a default write strategy according to the present invention.

8 is a block diagram schematically illustrating a general apparatus for obtaining asymmetry β of data read from a disk system.

The default recording strategy configuration method according to the present invention for achieving the above object is

An optical disc drive, comprising: a method of setting a default recording strategy for an unknown disc whose type of recording material is unknown;

Investigating optimal recording strategies for discs whose type of recording material is known;

Examining the distribution of the recording strategy according to the type of recording material and the optimum recording power with reference to the examined results;

Selecting a recording strategy showing the highest distribution according to the type and the optimum recording power of the recording material; And

And registering the selected recording strategy as a default recording strategy in accordance with the type and optimum recording power of the corresponding recording material.

Here, it is preferable that the optimum write strategy in the irradiation process is at least the delay time of the write pulse as a parameter.

The default recording strategy application method according to the present invention for achieving the above another object is

A method of applying a default recording strategy for an unknown disc in a disc drive having a recording strategy having the highest distribution as the default recording strategy for an unknown disc according to the type of recording material and the optimum recording power,

Determining the type of recording material from the disc identification information recorded on the disc when an unknown disc is loaded;

Recording test write pulses having different write powers in a test area on the disc;

Reading the signals recorded by the test pulses and selecting a test pulse having an optimal recording performance; And

And selecting and applying one of the default recording strategies in accordance with the type of the determined recording material and the value of the recording power corresponding to the test pulse selected in the sorting process.

Here, the selection process preferably selects a test pulse showing an optimal asymmetry among the signals recorded by the test pulses.

A recording medium according to the present invention for achieving the above another object is

An optical disc drive, comprising: a computer-readable recording medium recording a method of setting a default recording strategy for an unknown disc whose type of recording material is unknown;

Investigating the distribution of the recording strategy according to the type and the optimal recording power of the recording material with reference to the result of investigating the optimal recording strategies for the discs whose type of recording material is known;

Selecting a recording strategy showing the highest distribution according to the type and the optimum recording power of the recording material; And

The process of registering the selected recording strategy as a default recording strategy according to the type and optimum recording power of the corresponding recording material is recorded.

A recording medium according to the present invention for achieving the above another object is

A computer recording a method of applying a default recording strategy for an unknown disc in a disk drive having a recording strategy having the highest distribution as the default recording strategy for an unknown disc according to the type of recording material and the optimum recording power. In the recording medium readable by

Determining the type of recording material from the disc identification information recorded on the disc when an unknown disc is loaded;

Recording test write pulses having different write powers in a test area on the disc;

Reading the signals recorded by the test pulses and selecting a test pulse having an optimal recording performance; And

And selecting and applying one of the default recording strategies in accordance with the type of the determined recording material and the value of the recording power corresponding to the test pulse selected in the sorting process.

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

1 shows each area of a CD-R disc. The CD-R disc is divided into a lead-in region 102, a program region 104, and a lead-out region 106.

In the lead-in area 102, disc type, disc size, channel bit length, disc structure, recording power, and the like are recorded as absolute time in pregroove (ATIP) information. In addition, on the inner circumference of the lead-in area, the PCA (Power Callibration Area) 108 where the test is performed for automatic laser power control, and the recording position and the type of information are temporarily recorded while the information is recorded in the program area. Two are program memory area (PMA) regions 110.

ATIP is for recording CD characteristic information such as the capacity of the entire disc, current position, relative speed, purpose (for data or audio), production company, etc. and is a representative item in determining the recognition rate of a CD-R or CD-RW. . When a CD is inserted, the recorder first reads the ATIP to obtain the necessary information. If this information is not read correctly, an error may occur in which the medium is not recognized properly.

The disk type information is expressed using the Lead-In Start Time and the Last possible Lead-Out Start Time in the ATIP information, and is composed of a manufacturer code (M code) and a type code (T code).

The M code is represented by the first digit of the minute digits, second digits, and frame digits of the Lead-In Start Time information, and used by the recorder to recognize the disc manufacturer. do.

Table 1 shows an example of M code.

Manufacturer 1st code 2nd code A 97m14s30f-97m14s39f 97m40s20f-97m40s29f B 97m14s40f-97m14s49f 97m41s20f-97m41s29f C 97m15s10f-97m14s19f 97m40s50f-97m40s59f

In the lead-in start time information "97m14s30f", the first digit of minute digits, second digits, and frame digits, "97-14-3", represents the manufacturer, and each manufacturer Each time a unique code is assigned.

In Table 1, 1st code is used for CLV 1.2m / s, and 2nd code is used for CLV 1.4m / s.

T code represents the recording characteristics of the disc, and there are T1 code and T2 code. The T1 code is represented by the second digit of the frame of ATIP's Lead In Start Time. For example, in the 1st code of Company A in Table 1, 0 of 97m14s3 0 f and 9 of 97m14s2 9 f are T1 codes. The T1 code is called a master type code and serves as a super code of the T2 code.

In the T1 code, 0 to 4 represent Long strategy type, for example, Cyanine type media, and 5 to 9 represent Short strategy type, for example, Phthalocynine type media.

The T1 code can be assigned by the disc manufacturer when there is a big change in the characteristics of the disc. In this case, the value used in the range of 0 to 4 or 5 to 9 plus 1 is used.

The T2 code is represented by the second digit of the frame of ATIP's Last possible Lead-Out Start Time. The T2 code is called a sub type code and serves as a sub code of the T1 code.

The T2 code can be assigned by the disk manufacturer when there is a small change in the characteristics of the disk. In this case, the T2 code is changed by increasing or decreasing the previously used value by 1 in the range of 0 to 9. After changing to 9, increase the T1 code by 1 and reset to 0.

2 is a flowchart showing a conventional method of setting a recording strategy using a disc identification symbol.

First, write strategies set for the known disk are stored in the firmware of the disk drive.

When a disc is inserted, the disc drive reads M code, T1 code, and T2 code to recognize the type of disc (s202).

It is determined whether the code is recorded in the firmware (s204). If the code is recorded in the firmware, the corresponding recording strategy is read and applied (s206).

If the code is not written in the firmware, it is determined as one of four cases.

1) case 1; If there is a known M code or T1 code and the T2 code is unknown (s214)

That is, if the recording strategy corresponding to M code and T1 code is recorded in the firmware but there is no recording strategy corresponding to T2 code, the recording strategy corresponding to M code and T1 code recorded in the firmware Read and apply. (S206)

2) case 2; If there is a known M code or T2 code and the T1 code is unknown (s212)

That is, if the recording strategy corresponding to M code, T1 type and T2 code is recorded in the firmware but there is no recording strategy corresponding to T1 code, the recording corresponding to M code and T1 type recorded in the firmware Read and apply strategy (s206)

Here, T1 type means 0-4 range or 5-9 range in Table 1.

3) case 3; When the type of known M code or T1 is changed (s210)

That is, the recording strategy corresponding to M code and T2 code is recorded in the firmware, but there is no recording strategy corresponding to T1 type. Here, the change of the T1 type means a change between the ranges 0-4 and 5-9 in Table 1.

In this case, one of the default recording strategies recorded in the firmware is selected and applied.

4) case 4; Unknown M code (s208)

In other words, there is no recording strategy corresponding to M code in the firmware.

In this case, one of the default recording strategies recorded in the firmware is selected and applied.

In case 3 and case 4, the type of T1 code is determined (s216). In case of T1 code 0 to 4, a long type default recording strategy is applied (s218), and in case of 5 to 9 short type. Apply the default write strategy of (s220).

According to the conventional recording strategy setting method as shown in FIG. 2, when there is a recording strategy corresponding to M and T1 types by reading the M, T1, and T2 codes, the corresponding recording strategy is applied, and M and T1 are applied. If there is no recording strategy corresponding to the type, the type of the T1 code is determined, and one of the long type default recording strategy and the short type write strategy is selected and applied.

According to the conventional recording strategy setting method as shown in FIG. 2, the recording strategy is constructed for all kinds of CD-R discs and copes with them. In the case of a newly produced disc, the type of T1 code, that is, the recording material By default, the recording strategy set by default is used.

This conventional recording strategy setting method can be less problematic when there are fewer types of newly produced discs. However, it is experimentally confirmed that excellent recording characteristics are difficult to be secured and, in fact, there are many variations in the case where the recording strategies are separately recorded according to the actual recording materials of various types and multiple speeds. have.

According to the present invention, recording strategies applied to all kinds of CD-Rs are selected according to recording materials and recording powers, and stored as default recording strategies. In this case, excellent recording characteristics are ensured by selecting and using one of the default recording strategies depending on the recording material and the recording power.

3 is a waveform diagram showing recording pulses of a CD-R disc. FIG. 3A is a recording mark, and FIG. 3B is a recording pulse applied to the laser diode to form the recording mark shown in FIG. 3A. The recording pulse shown in FIG. 3B is a delay time Tf from the leading edge of the recording mark to the standing edge of the recording pulse, the overdrive power Po, the recording power Pk, and the falling edge of the recording pulse. It can be characterized by the pause time Te to the end edge. The delay time Tf and the pause time Te take into account the jitter characteristic due to heat accumulation in the recording mark. ^Over-drive power (Po) is selectively applied is determined by multiplying a predetermined value to the normal recording power (Pk).

4 is a graph showing the distribution of recording pulses for each recording optical power of a Cyanine series CD-R disc. In FIG. 4, the horizontal axis represents the recording power Pk, and the vertical axis represents the delay time Tf. The delay time Tf is expressed as a magnification for T, which is the inverse of the fundamental frequency.

The graph shown in FIG. 4 is obtained as a result of experimenting with most discs currently supplied on the market, and shows the most suitable delay time Tf for the recording power Pk.

Characteristic in FIG. 4 is that there are many disks having a delay time of 0.25T in an area of 136mW or less, and many disks having a delay time of 0.35T in an area of 138mW or more. In order to determine the most suitable delay time for a given recording power Pk, pulses having a given recording power Pk and various delay times are recorded on the disc, and these are read and the asymmetry (β) of the reproduction signal is read. The delay time of the recording pulse having the optimal asymmetry beta is selected from these.

5 is a graph showing the distribution of recording pulses for each recording optical power of a PhthaloCyanine-based CD-R disc. Also in FIG. 5, there are many disks having a delay time of 0.25T in an area of 130 mW or less, and many disks having a delay time of 0.35T in an area of 131 mW or more.

The results of the experiments shown in Figs. 4 to 5 show that suitable recording power and delay time may be different even for a disc manufactured by a recording material of the same type. In other words, when the recording strategy is determined depending on the type of the recording material as in the conventional method, an accurate recording pulse cannot be obtained and thus an efficient recording result cannot be obtained.

Accordingly, the present invention proposes a default recording strategy setting method for determining recording strategy not only by the type of recording material but also by recording power, and a recording strategy setting method using the same.

6 is a flowchart showing a preferred embodiment of the method for configuring a default write strategy according to the present invention.

First, the optimal recording strategies are examined for discs whose manufacturer and the type of recording material are known. (s602) The examined result is recorded in the firmware and provided to provide recording strategy for known disks.

The distribution of the recording strategy according to the type and the recording power of the recording material is examined with reference to the result of the investigation. (S604) For example, as illustrated in FIG. 4, Cyanine-based CD-R discs (recording material). In the classification according to the type, the distribution of the recording pulse of type A having a delay time of 0.25T is large at the lower part of the recording power Pk of 136 mW (classification according to the recording power), and the delay time at the upper part. It can be seen that the distribution of the B type recording pulse of 0.35T is large.

The results of this analysis show that the recording strategy with a delay time of 0.25T is optimal for Cyanine series CD-R discs with an optimal recording power of 136 mW or less, and the delay time for CD-R discs with Cyanine series and an optimal recording power of 138 mW or more. This recording strategy of 0.35T is optimal.

On the other hand, in the PhthaloCyanine series CD-R discs as shown in Fig. 5, the distribution of C type recording pulses having a delay time of 0.25T is large at the lower part of the boundary where the recording power Pk is 131 mW, It can be seen from the upper side that the distribution of write pulses of type D with a delay time of 0.35T is large.

The results of this analysis show that the write strategy with a delay of 0.25T is optimal for CD-R discs with the PhthaloCyanine series and an optimal recording power of 131 mW or less, and the delay time for CD-R discs with the PhthaloCyanine series and an optimal recording power of 132 mW or more. This recording strategy of 0.35T is optimal.

The recording strategy having the highest distribution is selected according to the type and the recording power of the recording material (s606).

4 and 5, the selection result of step s606 is as follows.

CD-R discs with a Cyanine series / optimal recording power of 136 mW or less; A type

CD-R discs with Cyanine series / optimum recording power of 138 mW or more; B type

CD-R discs with a PhthaloCyanine series / optimal recording power of 131 mW or less; C type

CD-R discs with a PhthaloCyanine series / optimal recording power of at least 132 mW; D type

The selected recording strategy is recorded on the firmware as the default recording strategy according to the type and the recording power of the corresponding recording material (s608).

The default recording strategy registered through step s608 is selected and applied when an unknown disc is loaded. When the disc is loaded, the drive reads the M, T1, and T2 codes, and if it is unknown, selects one of the four default write strategies registered in step s608.

The default write strategy according to the embodiment of the setting method but only determines the optimal delay time (Tf) for the recording power optimal delay time (Tf) for the recording power, optimum-over in accordance with the invention the ^drive power (Pe It is clear that it is also possible to investigate and apply the optimal down time Te.

FIG. 7 is a flow chart showing a preferred embodiment of the method for applying a default write strategy according to the present invention, showing an example of selecting one of the default write strategies set by the method shown in FIG.

Write strategies set for discs whose manufacturer and type of recording material are known and default write strategies for unknown discs are stored in the firmware of the disc drive. Here, the default recording strategies are created by the default recording strategy setting method as shown in Fig. 6, and are set according to the type of recording material and the optimum recording power.

4, 5, and 6, examples of default write strategies are as follows.

1) Long type (Cyanine series)

CD-R discs having an optimum recording power of 136 mW or less; A type of Fig. 4

CD-R discs with an optimum recording power of 138 mW or more; B type of Fig. 4

2) Short type (PhthaloCyanine series)

CD-R discs having an optimum recording power of 131 mW or less; C type of Figure 5

CD-R discs having an optimum recording power of 132 mW or more; D type of FIG.

When a disc is inserted, the disc drive reads M code, T1 code, and T2 code to recognize the type of disc (s702).

It is determined whether the code is recorded in the firmware (s704). If the code is recorded in the firmware, the corresponding recording strategy is read and applied. (S706)

If the code is not written in the firmware, it is determined as one of four cases.

1) case 1; If there is a known M code or T1 code and the T2 code is unknown (s714)

That is, if the recording strategy corresponding to M code and T1 code is recorded in the firmware but there is no recording strategy corresponding to T2 code, the recording strategy corresponding to M code and T1 code recorded in the firmware Read and apply. (S706)

2) case 2; If there is a known M code or T2 code and the T1 code is unknown (s712)

That is, if the recording strategy corresponding to M code, T1 type and T2 code is recorded in the firmware but there is no recording strategy corresponding to T1 code, the recording corresponding to M code and T1 type recorded in the firmware Read and apply strategy. (S706)

Here, T1 type means that in Table 1, the T1 code is in the range of 0-4 or 5-9.

3) case 3; When the type of known M code or T1 is changed (s710)

That is, the recording strategy corresponding to M code and T2 code is recorded in the firmware, but there is no recording strategy corresponding to T1 type. Here, the change of the T1 type means a change between the ranges 0-4 and 5-9 in Table 1.

In this case, one of the default recording strategies recorded in the firmware is selected and applied.

4) case 4; Unknown M code (s708)

In other words, there is no recording strategy corresponding to M code in the firmware.

In this case, one of the default recording strategies recorded in the firmware is selected and applied.

In case 3 and case 4, the type of the T1 code is determined. (s716) If the T1 code is a long type (when the T1 code is 0 to 4), the processes s718, s722, and s724 are performed. If one of the default write strategies is applied, and if the T1 code is a short type (when the T1 code is 5 to 9), steps s720, s726, and s728 are performed to apply the default write strategy of the short type.

In steps s718 and s720, predetermined test pulses are recorded in the test area on the disc, and the read-out pulses are read to determine an optimum recording power Pk.

The test area on the disc is set in the PCA area according to the standard of the CD-R system. The predetermined test pulses have a predetermined delay time Tf and different write powers Pk. The delay time is set to a value between 0.25T and 0.35T, but this is not necessarily the case.

The signals recorded on the test are read to screen test pulses that perform optimally. The recording power for this test pulse is known by the controller which controls the drive.

The asymmetry of the reproduction signal is examined to select a test pulse that shows the best performance.

FIG. 8 is a block diagram schematically illustrating a general apparatus for obtaining asymmetry β of data read from a disk system. The high pass filter 802, the record value detector 804, the low pass filter 806, and the bottom value are shown in FIG. The detector 808 includes a detector 810, a controller 810, and a memory 812.

In the apparatus shown in FIG. 8, the high pass filter 802, although not shown, performs high pass processing of the read signal RF input from the optical pickup unit of the optical disc system to remove low frequency components.

The peak value detector 804 detects the peak value P of the read signal noise canceled by the high pass filter 802, and the bottom value detector 808 detects the bottom value B of the noise canceled read signal. . The low pass filter 806 extracts the intermediate value C of the DC level by performing low pass filtering on the noise-rejected read signal.

The controller 810 controls the peak value P, the bottom value B, and the intermediate value C of the read signal detected by the peak value detector 804, the bottom value detector 808, and the low pass filter 806, respectively. The asymmetry β of the read signal is calculated by the following equation.

The controller 810 stores the asymmetry β obtained by Equation 1 in the memory 812. At this time, the write power Pk of the test power having the smallest value of the asymmetry β stored in the memory 812 is determined as the optimal write power.

One of the default recording strategies is selected according to the type of recording material determined in step s716 and the value of the optimum recording power determined in step s718 or s720 (s722 to s728).

For example, if the recording material determined in step s716 is a long type, and the optimal recording power determined in step s718 is 136 mW or less, that is, low power, a type A recording strategy is determined (s722). If the recording material determined in step S716 is of a long type, and the optimum recording power determined in step S718 is 138 mW or more, that is, a high power, a recording type of B type is determined (s724).

If the recording material determined in step s716 is a short type, and the optimum recording power determined in step s720 is 131 mW or less, that is, low power, a C type recording strategy is determined (s726). In addition, if the recording material determined in step s716 is a short type, and the optimal recording power determined in step s720 is 132 mW or more, that is, a high power, a recording type of D type is determined (s728).

According to the default recording strategy setting method according to the present invention, the recording material and the optimal recording power are investigated for the currently distributed disks, and a plurality of recording strategies suitable for the recording material are set on the basis of the irradiated result. Set the write strategy. Therefore, it is possible to apply a more efficient recording strategy by setting a default strategy for an unknown disk based on statistical similarity.

In addition, the default recording strategy selection method according to the present invention further determines the recording material and the optimal recording power suitable for the unknown disc, and applies the recording strategy suitable for the recording material and the optimal recording power. Excellent recording performance can be guaranteed.

The invention can be practiced as a method, apparatus, system, or the like. When implemented in software, the constituent means of the present invention are code segments that necessarily perform the necessary work. The program or code segments may be stored in a processor readable medium or transmitted by a computer data signal coupled with a carrier on a transmission medium or network. Processor readable media includes any medium that can store or transmit information. Examples of processor-readable media include electronic circuits, semiconductor memory devices, ROMs, flash memory, erasable ROM (EROM), floppy disks, optical disks, hard disks, optical fiber media, radio frequency (RF) networks, Etc. Computer data signals include any signal that can propagate over transmission media such as electronic network channels, optical fibers, air, electromagnetic fields, RF networks, and the like.

Specific embodiments shown and described in the accompanying drawings are only to be understood as an example of the present invention, not to limit the scope of the invention, but also within the scope of the technical spirit described in the present invention in the technical field to which the present invention belongs As various other changes may occur, it is obvious that the invention is not limited to the specific constructions and arrangements shown or described.

As described above, according to the method for setting a default recording strategy according to the present invention according to the present invention, it is possible to apply a more efficient recording strategy by setting a default strategy for an unknown disk based on statistical similarity. .

In addition, according to the default recording strategy selection method according to the present invention, better recording performance can be ensured by applying a recording strategy suitable for the recording material and the optimal recording power to an unknown disk.

Claims (6)

An optical disc drive, comprising: a method of setting a default recording strategy for an unknown disc whose type of recording material is unknown; Investigating optimal recording strategies for discs whose type of recording material is known; Examining the distribution of the recording strategy according to the type of recording material and the optimum recording power with reference to the examined results; Selecting a recording strategy showing the highest distribution according to the type and the optimum recording power of the recording material; And Registering the selected recording strategy as a default recording strategy according to the type and optimal recording power of the corresponding recording material. 2. The method of claim 1, wherein the optimal write strategy in the irradiation process is at least a delay time of the write pulse as a parameter. A method of applying a default recording strategy for an unknown disc in a disc drive having a recording strategy showing the highest distribution as the default recording strategy for an unknown disc according to the type of recording material and the optimum recording power, Determining the type of recording material from the disc identification information recorded on the disc when an unknown disc is loaded; Recording test write pulses having different write powers in a test area on the disc; Reading the signals recorded by the test pulses and selecting a test pulse having an optimal recording performance; And And selecting and applying one of the default recording strategies according to the determined type of recording material and the value of the recording power corresponding to the test pulse selected in the sorting process. 4. The method of claim 3 wherein the screening process selects test pulses that exhibit optimal asymmetry among the signals recorded by the test pulses. An optical disc drive, comprising: a computer-readable recording medium recording a method of setting a default recording strategy for an unknown disc whose type of recording material is unknown; Investigating the distribution of the recording strategy according to the type and the optimal recording power of the recording material with reference to the result of investigating the optimal recording strategies for the discs whose type of recording material is known; Selecting a recording strategy showing the highest distribution according to the type and the optimum recording power of the recording material; And And a process of registering the selected recording strategy as a default recording strategy according to the type and optimum recording power of the corresponding recording material. A computer recording a method of applying a default recording strategy for an unknown disc in a disk drive having a recording strategy having the highest distribution as the default recording strategy for an unknown disc according to the type of recording material and the optimum recording power. In the recording medium readable by Determining the type of recording material from the disc identification information recorded on the disc when an unknown disc is loaded; Recording test write pulses having different write powers in a test area on the disc; Reading the signals recorded by the test pulses and selecting a test pulse having an optimal recording performance; And And selecting and applying one of the default recording strategies according to the type of the determined recording material and the value of the recording power corresponding to the test pulse selected in the sorting process.