KR20070006439A - Recording power regulating method for optical disc recording apparatus - Google Patents

Abstract

A recording power control method of an optical disc device is provided to compensate for recording power so as to be an optimum power on the basis of the modulation value changed according to control of the recording power. An optical pick up(20) irradiates the laser beam having predetermined recording power on an optical disc and reads the signal recorded in the optical disc. A digital recording signal processing member(30a) adds the inputted digital data into an error correction code and converts the digital data into a recordable data format. A digital reproduction signal processing member(30b) restores the binary signal into the original video/audio data. A channel bit encoder(40) converts again the converted data into the bit stream. An optical driving member(41) outputs the light amount driving signal to the optical pick up. An RF(Radio Frequency) signal processing member(50) filters the signal from the optical disc and outputs the filtered signal as a binary signal.

Description

{RECORDING POWER REGULATING METHOD FOR OPTICAL DISC RECORDING APPARATUS}

1 is a diagram showing a PCA area and an RMA area allocated to a general recordable optical disc;

2 is a diagram showing a beta (β) characteristic of the asymmetric characteristic of a typical optical disk,

3 is a diagram showing modulation characteristics of a general optical disc;

FIG. 4 is a diagram illustrating a gamma (γ) curve using a modulation rate change rate and a change rate of recording power shown in FIG.

5 is a diagram showing the configuration of an optical disk apparatus to which a recording power adjusting method according to the present invention is applied;

FIG. 6 is a diagram illustrating a state of detecting a modulation value of previously recorded data during a buffer underrun appearing when recording an optical disc according to an embodiment of the present invention; FIG.

7 is a diagram illustrating a state in which recording power is increased or decreased based on a detected modulation value as shown in FIG. 6;

8 is a diagram showing a general increase / decrease curve of recording power;

FIG. 9 is a view showing a state in which test data is recorded by increasing or decreasing the recording power so as to follow the target power during a buffer underrun period appearing in recording an optical disc of data according to another embodiment of the present invention; FIG.

FIG. 10 is a view showing a state in which the power is long and following the target power by the increase / decrease adjustment operation of the recording power as shown in FIG. 9;

Fig. 11 is a flowchart for explaining the operation of the recording power adjusting method of the optical disk apparatus according to the present invention.

<Description of the symbols for the main parts of the drawings>

10: optical disc, 20: optical pickup,

30a: digital recording signal processing section, 30b: digital reproduction signal processing section,

40: channel bit encoder, 41: optical driver,

50: RF signal processing unit, 60: servo unit,

61: servo drive unit, 70: level detector,

80: microcomputer, 81: memory.

The present invention relates to a method for adjusting the recording power of an optical disk device. More particularly, the present invention relates to an optical disk device that checks the recording power at the time of buffer underrun that occurs when data is recorded on the optical disk. A recording power adjusting method.

Recently, a high-density optical recording medium capable of recording and storing high-quality video data and high-quality audio data for a long time, that is, an optical disc such as a DVD-R capable of recording and playing, has been developed and commercialized. And optical disc devices such as DVD recorders capable of recording and playing back audio data have been developed and used.

Such an optical disc such as a DVD-R has a power calibration area (PCA) area for performing an optimal recording power search (OPC) operation before a lead-in area, as shown in FIG. 1. And a recording management area (RMA) area are allocated, and the PCA area records a test area for testing laser recording power during OPC and a number of tests, that is, a recording number. It is divided into count areas.

The test area and the count area in the PCA area are divided into 100 partitions so that the OPC can be executed 100 times, so that the test can be executed up to 100 times, and the recording space remains after 100 times. Do not allow any further recording, even if it exists.

One partition of the test area is composed of 15 sectors, and one partition, that is, 15 sectors is used for one test recording. For this purpose, an optical disk device records an ATIP (Absolute Time In Pregroove) recorded on an optical disk. Read the information and divide the recording power into 15 steps based on the reference power recommended by the disc manufacturer to record the EFM (Eight to Fourteen Modulation) signal in the test area of the PC area.

Then, the recorded signal is reproduced and judged as an appropriate recording power when the peak hold and the bottom hold of the reproduced signal are properly balanced, and the program area is determined by the recording power value. Real data can be recorded in (Program Area).

)이 "0"에 가깝게 되어 대칭이 되는 파워를 최적의 기록 파워로 결정하게 되는 것이다. That is, after recording the EFM signal in the test area as illustrated in FIG. 2, the peak-to-peak value of the Hi-Fi signal for each recording power is examined when the signal is reproduced. β) value (i.e.

) Becomes close to " 0 " to determine the symmetrical power as the optimal recording power.

On the other hand, in the case of a DVD-RW capable of repeatedly recording, the asymmetry characteristic is not as good as that of the DVD-R, and it is difficult to use high power to secure the repeat recording characteristics. The method is also used.

As illustrated in FIG. 3, in the modulation method, after the EFM signal is recorded in the test region, the amount of light of the peak level and the bottom level of the RF signal reflected from the test region is checked during regeneration, and then modulated by calculating the checked amount of light. The degree value m (i.e., m = | Top |-| Bottom | / | Top |) is obtained, and the optimal recording power is determined using the gamma curve illustrated in FIG.

), 도 4에서 최적의 기록 파워(Po)는 감마 곡선의 이미 결정된 감마 타겟(γt)값에 해당하는 기록파워(Pt)에 광디스크의 제조시에 미리 결정되어 ATIP에 기록되어 있는 곱셈 인자(Multiplication Factor)를 곱하여 결정하게 된다. The gamma curve is a normalized slope of the modulation degree m and is expressed as an amount of change in modulation degree and a change in recording power (that is,

In Fig. 4, the optimal recording power Po is a multiplication factor previously determined at the time of manufacture of the optical disc and recorded in the ATIP at the recording power Pt corresponding to the predetermined gamma target value? T of the gamma curve. It is determined by multiplying by factor.

On the other hand, in the case of recording digital broadcast data or video / audio data with the optimal recording power set through testing in advance in the program area of the optical disk, the optical disk device has a high temperature caused by the high speed rotation of the optical disk or the startup of the optical pickup. Due to the factors, the recording power gradually changes from the optimal recording power value. Since there is no algorithm for checking the recording power midway during data recording, continuous recording of data with such a changed recording power value There is a problem that the data recording quality of the optical disc is inevitably deteriorated.

Accordingly, the present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to change the recording power by verifying the recording power during an idle period caused by a buffer underrun during data recording to an optical disc. The present invention provides a method of adjusting the recording power of an optical disk device, which makes it possible to compensate power to an optimal value.

It is another object of the present invention to record test data by increasing or decreasing the recording power in a buffer underrun condition that appears during data recording of an optical disc, and recording power based on a modulation value changed by the increase or decrease of the recording power. The present invention provides a method of adjusting the recording power of an optical disk device that enables compensation with an optimum power.

According to the present invention for achieving the above object, in the method for recording data at an optimal recording power in an optical disk, by increasing or decreasing the power value than the current recording power during a buffer underrun period appearing during data recording to the optical disk Recording test data; reading the recorded test data; detecting a signal change amount; and adjusting the power value so that the current recording power follows a preset target power based on the detected signal change amount. There is provided a recording power adjusting method of an optical disk device, comprising the steps.

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

That is, FIG. 5 is a diagram showing the configuration of an optical disk apparatus to which the recording power adjusting method according to the present invention is applied.

As shown in Fig. 5, the optical disk apparatus of the present invention is configured to irradiate a laser disk having a predetermined recording power to the optical disk 10 to record data or to read a signal recorded on the optical disk 10 from the reflected light of the laser light. 20, a digital recording signal processing unit 30a for adding an error correction code (ECC) to the input digital data and converting it into a recordable data format, and converting the binary signal reproduced from the optical disc 10 into original video / audio. The digital reproduction signal processor 30b for restoring and outputting the data, the channel bit encoder 40 for reconverting the data converted into the recordable format into a bit stream, and the optical quantity driving signal corresponding to the bit stream signal are optically picked up. RF signal outputting a binary signal by shaping the signal from the optical driver 41 and the optical disk 10 read by the optical pickup 20 The focusing / tracking servo of the optical pickup 20 and the rotation drive of the optical disc 10 are driven by a focusing error signal FE and a tracking error signal TE from the call processing unit 50 and the optical pickup 20. Modulation of the signal in the binary signal from the servo unit 60 for controlling, the servo driver 61 for controlling the rotation of the spindle motor 62 by the servo operation of the servo unit 60, and the RF signal processing unit 50. The level detector 70 which detects a degree value and the optical pickup 20 reproduces the recording data of the optical disc 10 at the time of buffer underrun appearing in the data recording state of the optical disc 10, and the level detector 70 The microcomputer 80 increases or decreases the recording power based on the modulation degree value detected by the non-volatile memory such as EEPROM, which stores the target beta value and target power, reference modulation degree, and target power value for each disk manufacturer. Consists of memory (81) It is sex.

As illustrated in FIG. 6, in the case of recording data on the optical disc 10, the speed at which data is accumulated in the buffer 42 and the speed at which data is actually written on the optical disc 10 are different from each other. A buffer underrun occurs between recording periods, resulting in an idle period of a certain period (i.e., 2 seconds in HQ mode, 12 seconds in EQ mode). A reproducing operation is performed during the idle period, so that the previously recorded signal is reproduced by the optical disc 10, and the level detector 70 detects a modulation degree value from the reproduced signal.

As illustrated in FIG. 7, when a modulation degree value is detected from the level detector 70, the reference modulation degree value stored in the memory 81 is compared with the detected modulation degree value. Power compensation is then performed to increase or decrease the write power so that the current write power approaches the target power value.

On the other hand, in the state where the relationship curve between the modulation degree m and the recording power P is obtained as shown in FIG. 7, if the current recording power P0 is lower than the target power according to an embodiment of the present invention, the power value is reduced. Compensation to increase to close to the target power, and if the current recording power (P1) is increased than the target power to reduce the power value to compensate to approach the target power, but the actual test considering the unrecorded high recording power As shown in FIG. 8, the characteristic curves of the modulation degree m and the recording power P appear in a form in which the modulation degree is inferior when the proper recording power Pc is greater than or equal to that shown in FIG. 8.

That is, as shown in FIG. 8, if the current recording power P0 is lower than the target power in the state where the target power and the parabola are in the same slope range, the power value is the same as the increase trend of the modulation degree m0 value. Can be compensated for approaching the target power, but increases from the target power while the current recording power P1 is at a different slope range 8b of the parabola from the target power, such as due to the external temperature of the system. If so, the algorithm according to an embodiment of the present invention is applied to increase the recording power in order to lower the modulation degree m1 value.

In order to overcome this, in another embodiment of the present invention, as shown in Fig. 9, during the buffer underrun period generated during data recording of the optical disc 10, the recording power is increased or decreased from the current recording power. The test data is recorded in the unrecorded section of the optical disc 10, and the recorded test data is read out to determine the change state of the modulation degree value, whereby the modulation degree m and the recording power P in which the current recording power is parabolic ), Which slope position of the characteristic curve is located, and the current recording power value is increased or decreased to follow the target power depending on whether or not the current recording power is located at the same slope as the target power.

That is, as shown in FIG. 10, after the test data is recorded by increasing (or decreasing) the power value at the current recording power P0, the modulation degree (m0) value detected by reading the test data is increased (or If it is, the current recording power P0 value is determined to be at the same slope 8a as the target power, and a compensation process is performed to increase the recording power value to follow the target power.

On the other hand, after the test data is recorded by increasing (or decreasing) the power value at the current recording power P1, and if the modulation degree m1 value detected by reading the test data is reduced (or increased), The current recording power p1 value is determined to be at an inclination position 8b different from the target power, and a compensation process is performed to reduce the recording power value to follow the target power.

Next, Fig. 11 is a flowchart for explaining the operation of the recording power adjusting method of the optical disk apparatus according to the present invention.

Hereinafter, the flowchart according to the embodiment of the present invention shown in FIG. 11 will be described in detail in parallel with the operation of the apparatus of FIG. 5.

First, when the optical disk 10 capable of recording data is mounted, the OPC operation is performed through the PCA area of the optical disk 10 (step S10), and the optimal recording is performed as a result of performing the OPC operation. The power is determined and recorded in the user area (step S11).

In this state, when the input data is converted into a recordable data format by the digital recording signal processing section 30a and reconverted into a bit stream by the channel bit encoder 40, the optical pickup 41 drives the optical pickup 41 to drive the optical pickup. In step 20, data can be recorded in a program area of the optical disc 10 at an optimal recording power (step S12).

On the other hand, the microcomputer 80 determines whether a buffer underrun occurs in the state of recording data on the optical disc 10 (step S13), and if it is determined that the buffer underrun has occurred, a predetermined test during the buffer underrun period is performed. When data is recorded in the unrecorded section of the optical disc 10, it is determined whether or not the recording power of the test data is increased by recording from the current recording power (step S14) to test with the recording power increased from the current recording power. Data is recorded (step S15).

In this state, the microcomputer 80 performs a reproducing operation so that the optical pickup 20 reads the test data recorded on the optical disc 10, and the level detector 70 modulates the test data. m) is detected (step S16).

The microcomputer 80 determines whether the modulation degree m of the test data detected by the level detector 70 is greater than the modulation degree value according to the current recording power (step S17), and detected from the test data. If it is determined that the modulation degree m is increased, as shown in FIG. 10, the current recording power is determined to be at the same inclination position between the stored target power and the parabola, which is preset in the memory 81, and follows the target power. The recording power is increased and adjusted as much as possible (step S18).

On the other hand, if it is determined that the modulation degree (m) detected from the test data is reduced, it is determined that the current recording power is at a different inclination position from the target power as shown in FIG. 10, and follows the target power. The recording power is adjusted to be reduced (step S19).

If it is determined in step S13 that a buffer underrun has occurred, it is determined whether or not the recording power of the test data is reduced from the current recording power when the predetermined test data is recorded in the unrecorded section of the optical disc 10 during the buffer underrun period. It is determined (step S20), and test data is recorded with the recording power reduced from the current recording power (step S21).

In this state, the microcomputer 80 performs a reproducing operation so that the optical pickup 20 reads test data recorded on the optical disc 10, and the level detector 70 modulates the test data. (m) is detected (step S22).

The microcomputer 80 determines whether the modulation degree m of the test data detected by the level detector 70 is less than the modulation degree value according to the current recording power (step S23), and detected from the test data. If it is determined that the modulation degree m has been reduced, the process proceeds to step S18 where the current recording power is determined to be at the same inclination position of the target power and the parabola, so that the current recording power can follow the target power. Increase the value.

However, if it is determined that the modulation degree (m) detected from the test data is increased, the process proceeds to step S19, where it is determined that the current recording power is at a different inclination position from the target power, and thus the current recording power. The recording power value is reduced and adjusted so that the tracker can follow the target power.

Then, when the idle period required by the buffer underrun has elapsed and a period in which data can be recorded again arrives (YES in step S24), the process proceeds to the step S12 again to increase or decrease the data at the recording power. When the buffer underrun occurs, the recording power is increased or decreased to continuously record the test data and compensate for the optimal recording power.

On the other hand, in the microcomputer 80, when the time point at which data recording to the optical disc 10 ends is reached (step S25), the data recording operation is terminated.

On the other hand, the present invention is not limited to the above-described typical preferred embodiments, but can be carried out in various ways without departing from the gist of the present invention, various modifications, alterations, substitutions or additions are common in the art Those who have knowledge will easily understand. If the implementation by such improvement, change, replacement or addition falls within the scope of the appended claims, the technical idea should also be regarded as belonging to the present invention.

As described above, according to the present invention, the test data is recorded by increasing or decreasing the power value from the current recording power during the buffer underrun period generated during the recording of data on the optical disk in the optical disk device, and according to the change value of the modulation degree detected from the test data. In addition, it is possible to increase or decrease the recording power by identifying whether the current recording power is at the same inclination or a different inclination position from the target power in a parabola representing modulation and recording power characteristics. It is possible to quickly grasp the change state and quickly perform the compensation process for the optimal recording power, and the data recording quality of the optical disc can be greatly improved.

Claims (6)

A method for recording data at an optimal recording power on an optical disc, A first step of recording test data by increasing or decreasing the power value than the current recording power during data recording to the optical disc; A second step of detecting the amount of change in the signal by reading the recorded test data; And And a third step of adjusting the power value so that the current recording power follows a preset target power based on the detected signal change amount. The method of claim 1, And the first to third steps are performed at the time of buffer underrun during the recording of the data. The method of claim 1, And in the first step, the test data is recorded in an unrecorded section of the optical disc. The method of claim 1, And wherein said second step is configured to detect a modulation value of said read test data as a signal change amount. The method according to claim 1 or 4, In the third step, if the modulation degree increases when the recording power of the test data is increased from the current recording power, the power value is increased and adjusted so that the current recording power follows the target power. And if the modulation degree decreases when the recording power of the test data is reduced from the current recording power, the recording power adjusting method of the optical disc apparatus, characterized in that the power value is increased and adjusted so that the current recording power follows the target power. . The method according to claim 1 or 4, In the third step, if the modulation degree decreases when the recording power of the test data is increased from the current recording power, the power value is decreased and adjusted so that the current recording power follows the target power. And if the modulation degree increases when the recording power of the test data is reduced from the current recording power, the power value is adjusted to decrease so that the current recording power follows the target power.

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