KR20030073541A - Compensation method of recording power of optical recording/reading apparatus and its recording method - Google Patents

Abstract

PURPOSE: A method for compensating recording power of an optical recorder and a recording method thereof are provided to prevent the deterioration of recording quality due to the change of the recording power by compensating the recording power to obtain a uniform RF value. CONSTITUTION: A method for compensating recording power of an optical recorder includes the steps of dividing a recording area of a disc into several zones(S135), measuring recording power at beginning time of the each zones by carrying out test recording per the zone and initial values of non-level reference signals for running OPC(S136), storing the recording powers and the initial values to a memory per the kind of disc, and carrying out data recording by reflecting the stored values to the beginning points per the zones according to time information provided from the disc(S137-S139).

Description

Compensation method of recording power and optical recording / reading apparatus and its recording method

The present invention compensates the recording power so that the recording quality is not deteriorated by the power fluctuation in the CAV (Constant Angular Velocity) recording method in which the spindle is rotated at a constant speed so that a constant RF (Radio Frequency) value is obtained. A recording power compensation method of a recording player and a recording method through the same.

Recently, recordable optical discs such as the compact disc recordable form (CD-Rs) and rewritable optical discs such as the compact disc rewritable form (CD-RWs) have been spreading. Such recordable optical discs (hereinafter, referred to as discs) include a packet input method, a track-at-once method, a session-at-once method, and a disk-at method. -Recording methods such as the disk-at-once method are selected.

Since the discs are rotated by constant linear velocity control (hereinafter referred to as CLV) in which the linear velocity is constant, recording is performed at a constant linear velocity also on the inner and outer circumferential sides of the recording area. As disc drive control rather than CLV control, a constant angular velocity (hereinafter referred to as CAV) is known. In this control, the angular velocity becomes constant.

In the CAV control, the constant rotational speed is maintained regardless of the spinning position on the disk, so that access is further improved than the CLV control. However, the recording speed varies depending on the recording position (outer circumferential side or inner circumferential side). Therefore, the data transfer rate is lower when recording is performed on the inner circumferential side than when recording is performed on the outer circumferential side.

In the conventional CAV method, the speed of the spindle motor is fixed at a speed that does not cause problems such as vibration and heat generation, thereby rotating a disk having a concentric track in a constant speed. Therefore, the disc rotation speed of the disc is the same as the disc's inner circumference and the outer circumference, so the data reproduction ratio of the disc increases from the inner circumference to the outer circumference. In other words, data is reproduced at a slow speed on the innermost side of the disc, and more and more data is reproduced toward the outer side. Eventually, the top speed comes from the very outside of the disc.

The recording power compensation method in the constant angular velocity recording method will be described with reference to FIG. 1.

First, it checks the counter area in the power calibration area (PCA) in the disk to determine the position to perform Optimum Power Control (OPC), moves to the data area in the PCA, and then actually writes to the area to be operated. (S101), sample the signal reflected from the optimal recording power (P ₀₁ ) used in the recording and the pit shaped on the disk by the recording pulses to a specific interval sample (B-Level) (B ₀₁ ) Is measured and stored (S102).

Then, after changing the speed (S103), the process moves to the PCC test area OPC2 again to perform the actual recording operation on the area where the PC will be performed (S104). At this time, the optimal power P ₀₂ and the optimal non-level B ₀₂ are stored (S105).

Then, the amount of power fluctuation dP ₀ and the optimum non-level fluctuation amount dB ₀ are calculated according to the speed from the above-described result of performing the PCC recording test (S106).

Then, after moving to the recording start position (S107), and when recording is started (S108), the optical recording player reads the time information (MSF: MinSecFrame) provided from the disc (S109), and the optimum recording power (P (MSF) ) And the non-level B (MSF) are compensated for to start recording (S110).

The optimal recording power P (MSF) and the non-level B (MSF) can be obtained as in Equation (1).

Here, N (MSF) is the recording speed in the recording position, N ₀₂ is the recording speed 2 in the OPC area, N ₀₁ is the recording speed 1 in the OPC area, and N _O1 is smaller than N _O2 .

Then, it is checked whether or not the recording is to end (S111). If the recording is continued, the above-described steps S109 and S110 are repeated to perform the recording operation on the disc, and the recording ends.

However, since the CAV recording method records the disk by rotating the disk at a constant angular speed as shown in FIG. 2, the linear velocity increases from the inner circumference to the outer circumference even on one disk, so that the recording power must be increased. Depends on the type of disc, the CAV speed, and the recording characteristics of the set.

The conventional CAV method does not divide the program zones into one zone and predicts the power increase according to the speed increase during the OPC operation, and does not accurately compensate the recording power. In the CAV method, the disc area is recorded as one zone. By performing the above, deterioration in recording quality due to power fluctuations occurs.

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problem. The present invention divides a recording area in a disc into several areas and performs trial recording for each area, so that the recording power and the running OPC at the start time in each area can be obtained. After measuring the region initial value of the non-level reference signal, the data is stored for each disc type, the non-level reference signal is generated in the region for the running OPC with reference to the above values for the corresponding disc during actual recording. It is an object of the present invention to provide a recording power compensation method and a recording method through the optical recording player to perform recording by inputting the.

1 is a flow chart showing a recording power compensation method in a constant angular velocity control method of a conventional optical recorder.

2 is a graph of recording speed change in a constant angular velocity recording method.

3 is a diagram illustrating an example of recording non-level measurement by region and recording power measurement at an area starting point in the recording power compensation method of the optical recorder according to an exemplary embodiment of the present invention.

4 is a flow chart showing a recording power compensation method in a constant angular velocity recording method in the optical recording player according to an embodiment of the present invention.

5 is a flowchart illustrating a recording method using recording power compensation in a constant angular velocity recording method in an optical recording player according to an exemplary embodiment of the present invention.

Figure 6 is a graph showing the recording power and non-level change in the constant angular velocity recording method according to an embodiment of the present invention.

7 is a block diagram showing a recording power compensation device of the optical recorder according to an embodiment of the present invention.

FIG. 8 is a view of each sub waveform of FIG. 7 according to an embodiment of the present invention; FIG.

In order to achieve the above object, the recording power compensation method of the optical recorder according to the present invention,

Dividing the recording area in the disc into several areas;

Performing a test recording (OPC) for each region to measure recording power at the start time of each region and region initial values of non-level reference signals for running OPC;

Storing the recording power at the measured area start time and the area initial value of the non-level reference signal in a memory for each disc type;

And checking the disc type when the actual disc is recorded, and reflecting the values stored in the memory of the disc to the starting point of each region by the time information provided by the disc.

In detail, each of the regions may be relatively wide at the same time interval or inner region, and relatively narrow at the outer circumferential region.

In detail, the non-level reference signal in each region is divided by the difference between the region non-level initial values at the beginning and end of one region and the difference in the start time at the two regions of the region, and then the disc recording time. Information is compensated for, and this value is added to the non-level initial value of the measured area.

In detail, the optimal recording power in each region is obtained by dividing the difference in the recording power at the start time at the start and end of one region by the difference between the start times of the two regions, and thereby compensating the disc time information. And the recording power at the start time of the measured area is added to this value.

The recording method through the recording power compensation of the optical recorder according to the present invention,

Checking the inserted disc manufacturer number and switching to the corresponding CAV speed; Setting a recording strategy corresponding to the disc manufacturer to a digital signal processor, and then moving to a PCA area to perform OPC; Checking a recording start time after performing the OPC and calculating a recording start power of a previously measured area; Searching for a desired recording start time and starting recording with the calculated recording start power; Checking the start information and the area of the disc at the start of recording and calculating a running OPC reference non-level for that area; And recording by adding the recording start power and the running OPC reference non-level of the corresponding area.

Referring to the accompanying drawings, the recording power compensation method and the recording method of the optical recorder according to the present invention as described above are as follows.

First, referring to FIG. 3, a recording area in a disc is divided into several areas (Zone1, Zone2, ..., Zone k, Zone N), and a test recording (OPC) is performed for each area so that a specific area (Zone k, k = 1, ..., the write power at a start time _{(T k, o = T 1} , o, T 2, o, ..., T k + 1, o) of N) (P _{k, 0)} The region initial values (B _{k, O} ) of the non-level reference signal for running optimal power control (ROPC) are measured. Here, the start point of one region is the end point of the next region.

At this time, the criterion for selecting the zone is a value that can maintain the variation of the RF beta (β) within the allowable value when divided into several zones. Zones can also be spaced at the same time intervals, and the inner area can be relatively wider and the outer periphery can be narrower to minimize the RF beta fluctuations in the outer circumference as much as possible in consideration of disk bending and deck skew.

The recording power (P _{k, 0} , k = 1,2, ..., N) at the region starting point is a measurement of the recording power at the region starting point, where the beta value of the RF is a desired beta value, The region initial value (B _{k, 0} , k = 1,2, ..., N) of the non-level reference signal for the running OPC is a measurement of the running OPC reference level at the starting point of the region where the RF beta is the desired beta value. to be. These recording powers P _{k, 0} and reference non-level initial values B _{k, 0} are normalized to power and non-levels obtained by performing OPC in PCA.

Here, the RF beta (β) value is a value given as a numerical value and is obtained by β = (A1-A2) / (A1 + A2). A1 is the value of holding the peak of RF with the center of RF as zero voltage (0V), and A2 is the bottom of RF with respect to zero voltage (OV) of the center of RF. The negative value held.

Then, test recording is performed on the recording power (P _{k, 0} ) at the start time of each region and the area initial value (B _{k, 0} ) of the non-level reference signal for running OPC, measured by the disc type. (Eg, ROM).

4 is a flowchart illustrating a method of setting a recording strategy for each disc according to an exemplary embodiment of the present invention.

When the disc is inserted (S121), the optical recorder checks the disc manufacturer number recorded on the disc (S122), and switches to a constant angular velocity (CAV) in response to the disc (S123).

In addition, in response to the disc manufacturer, a write strategy is set in the digital signal processor DSP (S124).

Then, the recording area in the disc is divided into several areas and test recording is performed for each area. First, after checking whether the current recording area constant value k is smaller than the number of all areas (S125), After searching the start position (S126), OPC is performed to measure the recording power (P _{k, 0} ) and the region initial value (B _{k, 0} ) of the non-level reference signal at the start time of the region. It is stored (S127).

Then, if the area constant is increased by one (k = k + 1) and the next area constant value is smaller than the total number of areas, the above operation is performed to perform OPC for each area and to record at the start time of each area. Steps S125 to S128 which measure and store the area initial values of the power and non-level reference signals are performed repeatedly.

When the area constant value of the S125 check result is larger than the total number of areas, the disc manufacturer number, the recording power at the stored area start time, and the area initial value of the non-level reference signal are stored in the memory (ROM), respectively. Done.

In this way, the recording power fluctuation or the non-level fluctuation according to the speed is different for each disc type, so the region start recording power (P _{k, 0} ) at each region start time and the non-level starting value (B _k ) for the running OPC. _{, 0} ) can be stored in the memory, so that the RF beta fluctuation can be minimized by recording with reference to the value when writing to the disk.

Referring to Figure 5, the actual recording method using a recording strategy according to an embodiment of the present invention will be described.

When the disc is inserted (S131), the optical recorder checks the disc manufacturer number (S132), and switches to the corresponding CAV speed corresponding to the checked disc (S133).

At this time, the recording strategy corresponding to the disc manufacturer is set in the digital signal processing unit (S134), and the OPC is performed by moving to the PCA test area (S135). At this time, the recording start time Ts in the OPC area is checked and the recording start powers P _{k and Ts} are calculated with reference to Equation 3 (S136). After searching for the desired recording start time Ts in the OPC area (S137), recording starts with the calculated recording power (P = P _{k, Ts} ) (S138). The recording power P at this time is equal to the calculated recording start power.

Then, the disc time information t and the zone Zone recorded on the disc are checked (S139), and the reference non-level B _{k, t} for the zone is calculated with reference to Equation 2 below. .

At this time _, the optimal recording power P = P _{k, Ts} + G (B _{k, t} , B) is set using the recording power P _{k, Ts} and the reference non-level B _{k, t} . The optimal recording power P is set by adding the gain values of the recording start powers P _{k, Ts} and the non-levels B _{k, t} at the start of the recording.

After confirming the area according to the time information of the disk as described above, the ratio is calculated and the recording power is compensated by referring to this. Thus, recording is performed with the compensated recording power for each area, and when the entire recording operation is completed, the recording ends. do.

Here, the reference non-level (B _{k, t} ) and the initial recording power in the area for the running OPC are calculated with reference to the values stored in the memory when the actual recording is performed, with reference to the drawings of FIG. 3. Can be.

The reference non-level (B _{k, t} ) for this running OPC is as shown in Equation 2.

Here, B _{k, t} is the reference non-level in the region k, B _{k, 0} is the non-level reference initial value of the region k _, and T _{k, 0} is the start time of the region k from the time information of the disk. Is the value to get. The reference non-level for this running OPC can be obtained by adding the region initial value of the non-level reference signal for the running OPC and the linear interpolated non-level over time.

Then, the recording start power P _{k, t} can be obtained as shown in Equation (3).

Where P _{k, t} is the recording start power in the area k, P _{k, 0} is the area initial value of the recording start power in the area _k, and T _{k, 0} is the start time of the area k from the disc time information. Is the value to get. The recording start power can be obtained by adding the recording power at the start time of each region and the linear interpolated recording power according to the region time.

In Equations 2 and 3, t is time information read from the disc as a time between the start time and the end time of one region.

As shown in FIG. 6, the present invention can express the optimal power and the optimal non-level value to keep the beta of RF constant when recording in a constant angular velocity recording method as a function of time, at the beginning of each region. The optimal power of (P _1,0 , P _2,0 , P _3,0 , P _4,0 , ..) and non-levels (B _1,0 , B _2,0 , B _3,0 , B _{4, 0} , ..) are the values that can be obtained by inserting the disk into the drive and performing OPC at that time.

Since the OPC is to find the recording power and the non-level reference for which the desired RF beta value is obtained for the disc, the reference non-level of the running OPC is linearly interpolated using the above values as shown in Equation 2 above. The recording start power can be obtained through linear interpolation as shown in Equation (3).

FIG. 7 is a block diagram illustrating a recording power compensating device of an optical recorder according to an exemplary embodiment of the present invention, and FIG. 8 is a sub waveform diagram of FIG. 7.

Referring to FIGS. 7 and 8, the first adder 101 adds and outputs a reference non-level for the running OPC and a negative input detection non-level signal B, and the controller 102 outputs the first. This controls the gain on the output of the adder. The second adder 103 adds and outputs the output of the controller and the recording power at the start of each region, and the LD power controller 104 receives the recording signal as shown in FIG. By controlling the output of the two-adder 103, the laser power as shown in FIG. 8B which is irradiated to the disk 106 through the laser diode LD, 105 is controlled.

Then, the non-level detection unit 108 detects the information, such as the recording power (C) of FIG. 8 reflected from the disc 106, that is, the recording power intensity through the photodiodes PD and 107. At this time, the stabilized portion of the detected signal becomes the non-level detection signal B, which is fed back to the first adder 101. Then, the non-level detection signal B is compared with the non-level reference signal B _{k, t} calculated by Equation 2, and the error signal is irradiated to the disk 106 by the LD power control unit 104. Controlling and recording power keeps the beta of the regenerated RF constant.

That is, when the recording signal generated by the encoder is input as shown in FIG. 8A, the LD power control unit writes a recording signal having a high level as a mark and a low level as a space. In the high level period, the LD power control unit turns on the laser to form a mark as shown in FIG. 8B on the disk through the laser diode. When the mark is formed, the amount of light reflected from the disk is detected by the photodiode in a waveform as shown in (c) of FIG. 8, and the portion where the signal as shown in (c) of FIG. 8 is stabilized is shown in (d) of FIG. It becomes a non-level detection signal. The non-level of FIG. 8D is information about the recording power intensity, which is compared with the non-level reference signal B _{k, t} calculated by Equation 2 and used as the error signal in the LD power controller. By controlling and recording the laser power irradiated onto the disc, the beta of the reproduced RF can be compensated constantly.

As described above, according to the recording power compensation method and the recording method through the optical recorder according to the present invention, in the CAV recording method in which the spindle is rotated at a constant speed and recorded, the variation or ratio of the recording power according to the speed for each disk type is different. -Since the level fluctuations are different, after dividing into a plurality of areas, each area start recording power and non-level start value are stored in the ROM, and when recording to the disc, the RF beta variation is made as small as possible. Thus, the recording quality is prevented from occurring due to power fluctuations.

Claims (11)

Dividing the recording area in the disc into several areas; Performing a test recording (OPC) for each region to measure recording power at the start time of each region and region initial values of non-level reference signals for running OPC; Storing the recording power at the measured area start time and the area initial value of the non-level reference signal in a memory for each disc type; Checking the disc type when recording the actual disc, and performing recording by reflecting the values stored in the memory for the disc to the starting point of each region by the time information provided by the disc. Recording power compensation method of the recording player. The method of claim 1, And each of the regions has the same time interval. The method of claim 1, Wherein each of the regions has a relatively wide inner zone and a relatively narrow outer periphery. The method of claim 1, The non-level reference signal in each area is compensated for the disc write time information after dividing by the difference between the area non-level initial values at the start and end of one area and the difference in the start time at the two points in the area. And the non-level initial value of the measured area is added to this value. The method of claim 1, The optimal recording power in each region is obtained by dividing the difference in the recording power at the start time at the start and end of one region by the difference between the start times of the two regions, and then compensates for the disc time information. And recording power at the start time of the measured area to be added to the recording power compensation method of the optical recorder. The method of claim 1, Each region initial value of the non-level reference signal for the running OPC is characterized in that the running OPC reference level measurement at the start of the region, the RF beta value is the desired beta value, The recording power compensation method of the optical recording player, characterized in that the recording power at the start time of each region is a measurement of the recording power at the starting point of the region in which the RF beta value is a desired beta value. Checking the inserted disc manufacturer number and switching to the corresponding CAV speed; Setting a recording strategy corresponding to the disc manufacturer to a digital signal processor, and then moving to a PCA area to perform OPC; Checking a recording start time after performing the OPC and calculating a recording start power of a previously measured area; Searching for a desired recording start time and starting recording with the calculated recording start power; Checking the start information and the area of the disc at the start of recording and calculating a running OPC reference non-level for that area; And recording at the recording power by adding the recording start power and the running OPC reference non-level of the corresponding area. The method of claim 7, wherein The reference non-level of the running OPC is Is obtained by linear interpolation, where B _{k, t} is a reference non-level in region k, B _{k, 0} is a non-level reference initial value of region k _, and T _{k, 0} is the start time of region k. A value obtained from time information of a disc, and t is a time between a start time and an end time of a region. The method of claim 7, wherein The recording start power is P _{k, t} is the recording start power in the area k, P _{k, 0} is the area initial value of the recording start power in the area _k, and T _{k, 0} is the start time of the area k. A value obtained from time information of a disc, wherein t is a time between a start time and an end time of one region. The method of claim 7, wherein Recording area by recording power compensation of an optical recorder, characterized in that each area is set within a range capable of maintaining a variation in RF beta within an allowable value. Refer to the recording power at the start time of the area measured in advance for each recording area and the area initial value of the non-level reference signal for the running OPC. Recording with recording start power; Compensating and recording the non-level reference signal in the compensated recording area and the recording start power in the area for each recording area according to the disc time information. How to record.