KR20070077723A - Optimal power controlling method for optical recorder - Google Patents

Abstract

A method for setting the optimum recording power in an optical recording apparatus is provided to accurately determine the optimum recording power considering the recording quality. A target photosensitive value of a front photo-diode is checked. The front photo-diode senses the optical output degree of a light source by recognizing an optical disc(S302). A tentative recording is performed on respective parts of a power calibration area of the optical disc by using recording powers of different values(S303). Photosensitive values of the front photo-diode for the recording powers are obtained(S304). The power calibration area is reproduced to obtain reproduction jitter values for respective parts thereof, and a photosensitive value of the front photo-diode corresponding to the smallest reproduction jitter value is obtained(S309). The optimum recording power is determined based on the target photosensitive value and the photosensitive value corresponding to the smallest reproduction jitter value(S310).

Description

Optimal recording power setting method of optical recorder {Optimal power controlling method for optical recorder}

1 illustrates an example of a process in which an optimal recording power setting is performed in a conventional optical recording apparatus.

2 shows a configuration of a part of controlling an output of a light source in the optical recording apparatus to which an embodiment of the present invention is applied.

3 is a flowchart illustrating a process of performing an embodiment of an optimal recording power setting method of the present invention.

4 shows an example of a graph estimated in step S306 while an embodiment of the present invention is performed.

{Description of main parts of the drawing}

210: optical disk 220: light source diode

230: photodiode 240: R / F section

250: front photodiode 260: front end IC

270 control unit 280 light source diode drive unit

290: storage means 401: change of the photosensitivity value

402: change in reproduction jitter value 403: target dimming value

404: Extinction value corresponding to the minimum value of the reproduction jitter value

The present invention relates to a method for setting an optimal recording power of an optical recording device, and more particularly, to a method for setting the recording power of an optical recording device in consideration of factors other than the beta (β) value considered in the existing optimal recording power setting. It is about.

The optical recording apparatus includes a laser diode that emits light of a specific wavelength, and drives the laser diode to irradiate a light beam of a predetermined energy on the information recording layer existing on the optical disk.

When the irradiated light beam is irradiated with energy that is large enough to change the physical characteristics of the information recording layer, the information can be recorded on the optical disc, or the information recorded on the optical disc by irradiating a small energy light beam that does not change the physical characteristics. Can play. The optical recording apparatus can record or reproduce data of the optical disc by adjusting the power of the light beam, and there is power of the light beam suitable for recording or reproduction for each optical disc.

In particular, when the optical recording apparatus records information on an optical disk capable of recording, the optical recording apparatus performs a process of setting a recording power suitable for the disk. The optimal power control (OPC) is performed by performing a test recording using a plurality of levels of recording power in a test area on an optical disc, and then reproducing the test recorded result to find an optimal recording power. Is performed. To this end, the optical disc has a power calibration area (PCA) which is a test recording area in which no data is recorded in the innermost periphery.

In more detail, FIG. 1 illustrates an example of a process in which an optimal recording power setting is performed in a conventional optical recording apparatus.

In the process shown in Fig. 1, when the disc is inserted into the optical recording apparatus, it is determined what kind of recording disc the inserted disc is, R (recordable) or RW (rewritable) (S101). Check (S102). From the maker code, a database-based write strategy table can be identified according to the type and recording speed of the disc.

Subsequently, an appropriate range of the target recording power value Pin and the target beta value recorded on the disc is read out (S103). Test recording is performed in a separate area in the PCA of the optical disc using predetermined values around the target recording power value (S104).

If the optical disc is an R-disc, the beta value is checked by reproducing the test recorded area (S105), and whether the beta value is within an appropriate range (S106) to determine an optimal recording power (S108). The beta value is a parameter indicating up and down symmetry in the waveform of the high frequency reproduction signal when detecting a reproduction signal (high frequency reproduction signal) proportional to the amount of light reflected from the optical disc. Among the beta values of each region in the PCA, the beta value that minimizes jitter is determined to be within an appropriate range, and the recording power corresponding to the beta value is selected as the optimal recording power. If the beta value is not in the proper range, the process of confirming the beta value by changing the value of the target recording power (S107) is repeated.

Similarly, when the optical disc is an RW-disc, the gamma value, which is a parameter related to the reproduction signal reflected from the test recording area of the optical disc, is checked to determine the maximum power, erase power, and base power value.

The existing optimal recording power setting method as described above obtains the target recording power and the target beta value appropriate range from the data recorded on the disk. If the information inherent in the disc is read incorrectly, the determination of the optimal recording power may fail or the recording power may be determined to an incorrect value. In addition, due to the temperature characteristic of the laser diode, a power different from the actual one may be derived.

Therefore, there is a need for an apparatus and method for setting optimal recording power capable of setting the optimal recording power to a more accurate value.

An object of the present invention devised to solve the above problems is to determine the optimal recording power in consideration of both factors, which are expected to be optimal values and the predetermined target optimal recording value and reproduction jitter value by test recording. It is to provide an optimal recording power setting method.

The method of setting an optimal recording power of the optical recording apparatus according to the present invention includes a first step of identifying a target photosensitive value of a front photodiode for recognizing an optical disk and detecting a light output level of a light source; A second step of performing trial recording using different recording powers for each part of the power control area PCA of the optical disc; A third step of acquiring a photosensitive value of the front photodiode for the recording power used for the test recording for each part; Reproducing the power control region to obtain a reproduction jitter value for each portion to identify a photosensitive value of the front photodiode corresponding to a portion where the reproduction jitter value is minimum; And a fifth step of determining an optimum recording power based on a photosensitive value corresponding to a portion where the target photosensitive value and the reproduction jitter value are minimum.

In the present invention, in the third step, it is preferable to obtain a photosensitive value of the front photodiode during the test recording of the second step for each part.

In the present invention, the fourth step includes estimating a change graph of the reproduction jitter value with respect to the photosensitive value of the front photodiode for the test-recorded portion of the power control region; Determining whether there is a minimum value of a reproduction jitter value in the graph; In the case where there is a minimum value in the graph, it is preferable to include a step of identifying a photosensitive value corresponding to the minimum value. In this case, after the step of determining whether the minimum value of the reproduction jitter value exists in the graph, when the minimum value of the reproduction jitter value does not exist in the graph, performing a process after the second step using different recording powers. More preferred.

In the present invention, the fifth step preferably determines the recording power corresponding to the photosensitive value falling within the range between the target photosensitive value and the photosensitive value corresponding to the portion where the reproduction jitter value is the minimum as the optimum recording power.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In adding reference numerals to components of the following drawings, it is determined that the same components have the same reference numerals as much as possible even if displayed on different drawings, and it is determined that they may unnecessarily obscure the subject matter of the present invention. Detailed descriptions of well-known functions and configurations will be omitted.

2 shows a configuration of a part of controlling an output of a light source in the optical recording apparatus to which an embodiment of the present invention is applied.

The optical recording device shown in FIG. 2 is a light source diode 220 that emits light in an optical pickup for irradiating light onto the optical disc 210 to record or read data, and a photo for receiving light reflected from the optical disc 210. A diode 230, an R / F unit 240 for generating a signal such as a high frequency reproduction signal, a reproduction jitter, and the like, and a front photodiode receiving a portion of the light emitted from the light source diode 220 according to the photodetection result of the photodiode. 250, a front end IC 260 that detects a light output level of the light source diode 220 from the light reception result of the front photodiode 250, a light reception result of the photodiode 230, and the front end IC 260. A control unit 270 for determining the recording power of the light source diode based on the detection result of the light source, a light source diode drive unit 280 for driving the light source diode 220 according to the recording power determined by the control unit 270, and Each disc that was previously recognized in the recording apparatus includes a storage means 290 that stores the optimal recording power.

3 is a flowchart illustrating a process of performing an embodiment of an optimal recording power setting method of the present invention.

In the embodiment of Fig. 3, when the disc is inserted into the optical recording apparatus, the disc maker code is checked (S301), and after reading the reproduction control parameters such as the recording strategy corresponding to the disc and the target photosensing value information (S302), The test recording is performed using different recording power for each part of the power control area PCA (S303), and at the same time as the test recording, the photosensitive value of the front photodiode corresponding to the recording power of each part is obtained. (S304), reproducing the test-recorded portion to obtain a reproduction jitter value for each portion (S305), and estimating a graph indicating a relationship between the photosensitive value and the reproduction jitter value of the front photodiode (S306). Depending on whether or not the minimum value of the reproduced jitter value exists (S307), when the minimum value does not exist, the recording power for each part is changed (S308), or test recording is performed again. If there is a small value, the photosensitive value of the front photodiode corresponding to the minimum value is checked as an optimal photosensitive value (S309), and the recording power corresponding to the optimal photosensitive value is determined as an optimal recording power (S310). Optimal recording power setting of the optical recording apparatus is performed.

One embodiment of the method for setting the optimum recording power of FIG. 3 is preferably performed in the structure of the optical recording apparatus as shown in FIG. Hereinafter, the present invention will be described with reference to FIGS. 2 and 3.

In the optical recording apparatus shown in FIG. 2, recording and reproduction are performed by irradiating light onto the optical disc 210 from the light source diode 220 in the optical pickup. The photodiode 230 receives light reflected from the light source diode 220 to the optical disc 210 and the R / F unit 240 stores information stored in the optical disc according to the light reception result of the photodiode 230. Generate a playback signal or generate a playback jitter signal to read < RTI ID = 0.0 >

The light output degree of the light source diode 220 is controlled by the light source diode drive unit 280, and receives a predetermined ratio of light emitted from the light source diode 220 to the optical disk by the front photo diode 250. According to the amount of light received by the front photodiode 250, the front end IC 260 detects the degree of light output of the light source diode 220.

The controller 270 adjusts reproduction parameters such as a target dimming value of the optical disc according to the values of the reproduction signal and the reproduction jitter generated by the R / F unit 240 and the degree of light output detected by the front end IC 260. The reading power is determined by determining the light output level of the current light source diode. The light source diode driver 280 drives the light source diode 220 according to the recording power determined by the controller 270.

In the embodiment of Fig. 3, the optical disc is inserted into the optical recording device to start the optimal recording power setting operation, and the optical recording device checks the disc maker code of the optical disc using the optical pickup (S301). The disc maker code is a unique identification code for one-to-one matching with a recording strategy table for each media.

Next, the database of the recording strategy table corresponding to the disc maker code is read (S302). The recording strategy table is preferably stored in advance in the storage device 290 or the like in the optical recording device. From this, the timing related parameter of the recording pulse and the target photosensitive value of the front photodiode 250 can be obtained. The target dimming value is to set the dimming value of the front photodiode 250 correspondingly in anticipation of the optimal recording power for the recording strategy when setting the recording strategy for each optical disc.

Subsequently, test recording is performed on the power control area PCA on the optical disc (S303). The test recording is performed by dividing the power adjusting area into a predetermined number of parts and using different recording power for each part. The recording power for each part of the test proxy may also include recording power corresponding to the read target dimming value, and as recording power changing in units of peripheral steps around the recording power corresponding to the target dimming value. It is preferable to carry out the test record.

While performing the test recording, the front photodiode 250 receives the light emitted from the light source diode 220 at a predetermined ratio, so that the front end IC 260 obtains a photosensitive value for each part of the test recording (S304). . The front end IC 260 preferably obtains an average level of the photosensitivity value for each part of the power control region and displays it as a digitized level.

After the test recording is completed, the reproduced jitter value is calculated by the R / F unit 240 for each part according to the light receiving result of the photodiode 230 by reproducing the test recorded region (S305). The R / F unit 240 preferably obtains an average level of reproduction jitter for each portion of the power control region and displays the average level of the reproduction jitter in a digitized level.

The controller 270 controls the reproduction jitter for the photosensitive value from the photosensitization value from the front end IC 260 and the reproduction jitter value from the R / F unit 240 corresponding to each part of the test recorded power adjustment region. A graph of the values is estimated (S306).

Subsequently, it is determined whether there is a minimum value of the reproduction jitter value in the graph (S307). If there is a minimum value of the regeneration jitter value, the optimum value is determined by determining the value of the photosensitive value corresponding to the minimum value (S309).

)은 목표 감광 값(

)과 상기 재생지터 값의 극소값에 해당하는 감광 값(

)으로부터 도출된다. 상기 최적 감광 값은 다음의 수학식 1과 같이 상기 목표 감광 값과 재생지터 값의 극소값에 해당하는 감광 값에 소정의 가중치를 준 계산에 의해 도출될 수 있다.The optimal dimming value (

) Is the target dimming value (

) And a photosensitive value corresponding to the minimum value of the reproduction jitter value (

Is derived from The optimal dimming value may be derived by a calculation given a predetermined weight to a dimming value corresponding to a minimum value of the target dimming value and the reproduction jitter value as shown in Equation 1 below.

와

는 예를 들면 각각 0.6과 0.4이며, 이 경우 상기 최적 감광 값은 상기 목표 감광 값과 재생지터 값의 극소값에 해당하는 감광 값 사이의 범위에 속한다.In Equation 1

Wow

Is, for example, 0.6 and 0.4, respectively, in which case the optimum dimming value falls within a range between the dimming value corresponding to the minimum value of the target dimming value and the reproduction jitter value.

4 shows an example of a graph estimated in step S306 while an embodiment of the present invention is performed. A change 401 of the photosensitive value and a change 402 of the reproduction jitter, which are changed step by step, are shown for each part on the power adjustment area.

The photosensitive value changes in one dimension in proportion to the recording power, but the reproduction jitter value does not necessarily change in one dimension in accordance with the recording power. It can be seen that the recording power becomes optimal when the reproduction jitter value is minimum, but it is inefficient to check the reproduction jitter value for all the recording powers. Since the reproduction jitter value is considerably larger in the test recording area using the recording power having a difference with the optimal recording power, the minimum value exists within the range by estimating the change graph of the reproduction jitter value in the test recording area as described above. In this case, it is determined that the reproduction jitter value is the minimum value at the minimum value.

When there is a minimum value of the reproduced jitter value as shown in the graph, an optimal photosensitive value may be derived using the target photosensitive value 403 and the photosensitive value 404 corresponding to the minimum value of the reproduced jitter value.

Subsequently, the control unit 270 determines the recording power corresponding to the derived optimal photosensitive value (S310) and applies the light source diode 220 to the light source diode 220 through the light source diode drive unit 280, thereby completing the setting of the optimal recording power.

On the other hand, if there is no minimum value of the reproduction jitter value in the step (S307), by changing the recording power to be used for the test recording for each part of the power control area (S308), performing the test recording (S303) To start again.

On the other hand, in the case of RW discs in addition to R-disc which determines only recording power, if recording power is determined, erasing power and the like can be derived based on the recording power. You can set the power.

As described above, in setting the recording power of the optical recording apparatus, in addition to the target dimming value of the front photodiode, a factor of the dimming value for minimizing the reproduction jitter value related to the recording quality is further considered. As a result, even if the recording power value set according to the predetermined target dimming value is not optimal according to the environmental characteristics and temperature characteristics of the light source diode, the recording power can be set to a more optimal value in consideration of the recording quality. Reliability is also improved.

As described above, it has been described with reference to the preferred embodiment of the present invention, but those skilled in the art various modifications and changes of the present invention without departing from the spirit and scope of the present invention described in the claims below I can understand that you can.

As described above, according to the present invention, the recording power is set in consideration of the factors related to the recording strategy of the optical disc and the factors related to the recording quality at the same time, so that the recording power can be set to an optimal value, thereby improving the recording quality.

Claims (5)

A first step of recognizing an optical disk and identifying a target photosensitive value of a front photodiode for detecting a light output level of a light source; A second step of performing test recording using different recording power values for each part of the power calibration area (PCA) of the optical disc; A third step of acquiring a photosensitive value of the front photodiode for the recording power used for the test recording for each part; Reproducing the power control region to obtain a reproduction jitter value for each portion to identify a photosensitive value of the front photodiode corresponding to a portion where the reproduction jitter value is minimum; And And a fifth step of determining an optimum recording power based on a photosensitive value corresponding to a portion where the target photosensitive value and the reproduction jitter value are minimum. The method of claim 1, wherein the third step obtains a photosensitive value of the front photodiode while performing the test recording of the second step for each part. The method of claim 1, wherein the fourth step Estimating a graph of a change in reproduction jitter value with respect to a photosensitive value of the front photodiode for the test recorded portion of the power control region; Determining whether there is a minimum value of a reproduction jitter value in the graph; And determining a photosensitive value corresponding to the minimum value when the minimum value exists in the graph. 4. The method of claim 3, wherein after determining whether there is a minimum value of the reproduction jitter value in the graph, when the minimum value of the reproduction jitter value does not exist in the graph, a process after the second step is performed using different recording power. A method of setting an optimum recording power of an optical recording apparatus, characterized in that it is performed. 2. The method of claim 1, wherein the fifth step determines the recording power corresponding to a photosensitive value falling within a range between the target photosensitive value and a photosensitive value corresponding to a portion where the reproduction jitter value is minimum. Optimal recording power setting method for an optical recording device.

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