KR20070006452A - 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 verify the recording power during an idle period generated due to the buffer under-run. When an optical disc is seated, an OPC(Optimum Power Calibration) operation is performed through a PCA area of the corresponding optical disc(S10), so that the optimum recording power is determined and recorded in the user area(S11). When the inputted data are converted into a recordable data format and then also converted into bit stream by a channel bit encoder, the data are recorded in a program area of the optical disc with the optimum recording power(S12). A microcomputer discriminates whether the buffer under-run is generated(S13). If the buffer under-run is generated, the reproduction operation is performed and an optical pick-up reads the previously recorded signal of the optical disc(S14) and a level detector detects the modulation degree of the recording signal(S15).

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 of multimedia data according to 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 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.

Another object of the present invention is to enable an optical disc to reproduce a previously recorded signal in a buffer underrun condition appearing at the time of data recording of an optical disc, and to compensate for the changed recording power based on a modulation value detected from the reproduction signal. It is to provide a method of adjusting the recording power of the device.

In order to achieve the above object, according to the present invention, there is provided a method for recording data on an optical disc at an optimal recording power, the method comprising: reading out a signal recorded during data recording on the optical disc and based on the read signal; The present invention provides a method of adjusting the recording power of an optical disc device, the method comprising: detecting a current recording power, and compensating for the current recording power based on a preset target power.

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 in the buffer underrun which appears 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 current recording power is targeted by comparing a reference modulation degree value stored in the memory 81 with the detected modulation degree value. Power compensation is performed to increase or decrease the corresponding write power to approach the power value.

Meanwhile, the recording power-modulation degree graph of FIG. 7 is obtained through the curve fitting process from the respective points detected by the OPC for the test area PCA. That is, when the modulation degree value for the values other than the measured points is obtained, the corresponding recording power value is corrected from the curve-fitted graph.

Next, FIG. 8 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. 8 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 where data is recorded on the optical disc 10 (step S13), and if it is determined that the buffer underrun has occurred, the playback operation is performed to perform the optical operation. The pickup 20 reads out the previously recorded signal of the optical disc 10 (step S14), and the level detector 70 detects the modulation degree m of the recording signal (step S15).

The microcomputer 80 compares the modulation degree m of the recording signal detected by the level detector 70 with a reference modulation degree value pre-stored in the memory 81, so that the detected modulation as shown in FIG. It is judged whether or not the current recording power related to the figure (m) is lower than the target power associated with the reference modulation degree (step S16).

As a result of the determination, if it is determined that the current recording power value is lower than the target power by comparing the modulation degree, a compensation process of increasing the current recording power closer to the target power is performed (step S17).

However, if it is determined by comparison of the modulation degrees that the current recording power value is greater than the target power, compensation processing is performed to reduce the recording power closer to the target power (step S18).

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 S19), proceeds to the step S12 again and increases or decreases from the previous recording stop position. Data can be recorded at the compensated write power, and a process for checking the current write power and compensating for the optimum write power each time a buffer underrun occurs is continuously performed.

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 S20), 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, by detecting a modulation degree value of a signal reproduced by reproducing a signal already recorded during a buffer underrun period generated during recording of data on an optical disc in an optical disc device, the detected modulation degree value is referred to. By comparing the modulation degree, it is possible to grasp the state in which the current recording power has changed with respect to the target power determined in relation to the reference modulation degree, and to increase and decrease the changed recording power to be closer to the target power. Even if is changed, it is possible to immediately grasp the change state and to quickly perform the compensation process for the optimum recording power, and the data recording quality of the optical disc can be greatly improved.

Claims (4)

A method for recording data at an optimal recording power on an optical disc, A first step of reading out a recorded signal during data recording to the optical disc; A second step of detecting a current recording power based on the read signal; And And a third step of increasing or decreasing the current recording power based on a predetermined target power. 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, The second step may include detecting a modulation value of the read signal; Finding a current reference power value associated with the detected modulation degree value. The method according to claim 1 or 3, The third step may include comparing the detected modulation degree value with a preset reference modulation degree to increase or decrease the current recording power to approach a target power associated with the reference modulation degree. .

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