KR20010056435A - Optical writing method - Google Patents

Abstract

PURPOSE: An optical recording method is provided to sample an optimum condition according to kind and state of a disk for operating recording. CONSTITUTION: A specific data is recorded and reproduced for reading the data. Length of a mark and a space is decided by a table of recording the data. Then, an error pattern is detected for length in a rising edge and a falling edge generated in a read data. Then, the detected change in length of the error pattern is renewed in the error detect table. A recording condition is adjusted according to renewed frequency of a same error pattern. Then, the renewed error detect table is renewed in a base table. In case of a high frequency for the error pattern having length change in both edges, a recording power is adjusted. In case of a high frequency for the error pattern having length change in one edge, a recording stratagy is adjusted.

Description

Optical writing method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording method of a rewritable optical disc, and more particularly to an optical recording method in which predetermined data can be adaptively updated by recording / reproducing predetermined data to analyze error patterns thereof.

Recently, the demand for large capacity has increased in the field of optical recording / reproducing or magneto-optical recording / reproducing. Accordingly, in a recording medium such as a DVD-RAM (Digital Versatile Disc-Random Access Memory), a mountain / gol recording method for recording information in both land and groove has been proposed.

When the high frequency signal recorded as described above is reproduced, the peak is reproduced as a mark and the valley is reproduced as a space. The reproduced data shows how the high frequency signal is recorded. That is, it changes depending on the change of the recording pulse shape, media characteristics, and recording conditions.

According to the shape of the above recording pulse, it is recorded as a continuous constant signal irrespective of grooves and lands in synchronization with the rising edge and the falling edge.

However, conventionally, when a recordable optical disc driver is constructed, the set recording strategy is always fixed and used regardless of the type of the disc. Accordingly, the recordable optical disc has a different jitter value during recording / reproduction due to the type of the disc or the same disc, even if the disc is the same due to the characteristics of the recording film and the tilt.

In particular, high-density and high-definition discs require high-definition and large-capacity optical recording techniques, resulting in narrower track widths and shorter recording marks, which have a greater effect. If different manufacturers have different recording strategies, the driver cannot take different recording strategies, resulting in severe variations in recording / playback characteristics.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and by recording / reproducing a predetermined high frequency signal, analyzing an error pattern according to the length variation of the reproduced data, and reflecting it on a recording strategy to rewrite the disk, It is an object of the present invention to provide an optical recording method capable of extracting and recording an optimal recording condition according to the type or condition.

1 is a block diagram showing an embodiment of an optical recording apparatus according to the present invention.

2 (2a, 2b) are flowcharts showing an embodiment of the optical recording method according to the present invention;

3 is a waveform diagram showing the relationship between the length of the mark to be compared and the length of the space before and after according to the present invention.

Fig. 4 is a diagram showing error patterns that may appear in marks when recording data is reproduced according to the present invention.

Figure 5 shows a number of edge tables arranged for optical recording in accordance with the present invention.

<Description of the reference numerals for the main parts of the drawings>

10 ... optical disc 11 ... optical pickup

12 ... Playback section 13 ... Playback data storage section

14 ... System control unit 15 ... Optical disc control unit

16 ... Register

In the optical recording method according to the present invention for achieving the above object, an error pattern generated by recording a predetermined high frequency signal, reproducing it, and reading the detected high frequency signal is compared with the high frequency signal, and the detected error is detected. The recording conditions of the optical disc are changed and rewritten according to the frequency of the patterns.

In the present invention, when the error pattern is an error pattern in which the length variation of the data occurs at both edges (rising edge, falling edge), the recording power is increased or decreased according to the frequency of the error pattern and the degree of variation in the length. do.

In the present invention, if the length variation of the data is an error pattern generated at one edge, the recording pulse is adjusted according to the frequency of the error pattern and the degree of variation of the length.

In the present invention, the detection element of the error pattern is characterized by detecting the length of the mark to be compared, the length of the space before and after the mark adjacent to the mark, and the moving length of the rising edge and the falling edge, respectively.

In the optical recording method according to the present invention, the length variation of the rising edge and the falling edge of data read by recording and reproducing a predetermined signal is updated in the error detection table by comparing with the basic recording table of the signal, and the updated error. The recording conditions are changed according to the degree of the appearance of data having the same length variation from the detection table.

Hereinafter, with reference to the accompanying drawings as follows.

1 is a configuration diagram showing an embodiment of an optical recording apparatus according to the present invention, FIG. 2 is a flowchart showing an embodiment of the optical recording method, and FIG. 3 shows the relationship between the length of a mark to be compared and the length of a space before / after. 4 is a view showing waveforms, and FIG. 4 is a diagram showing error patterns that may appear in marks when recording data is reproduced, and FIG. 5 is a diagram showing a plurality of edge tables provided for optical recording.

First, referring to FIG. 1, an optical pickup 11 that detects a light source generating a light beam to be irradiated onto the optical disc 10 and an optical signal reflected by the optical disc 10 as an electrical signal, and the optical pickup 11. A reproduction unit 12 for reading and reproducing the recording pulse of the electrical signal detected by the data; and a reproduction data storage unit 13 for storing the data RD_data read by the reproduction unit 12, and the reproduction data. The system control unit 14 which receives the data of the storage unit 13 and controls the recording power adjustment WR_PWR_CON and the write strategy control signal WR_STR_CON, and the write strategy control signal of the system control unit 14. Accordingly, the optical disk controller 15 outputs pulses to be recorded on the actual optical disk 10, and the recording pulses of the optical disk controller 15 are adjusted by the recording power of the system controller 14 to adjust the light source of the optical pickup 11. It consists of a recording unit 16.

The optical recording method of the present invention configured as described above will be described with reference to the accompanying drawings.

First, referring to FIG. 1, the predetermined high frequency signal REF_Data recorded on the optical disc 10 is a table 1 which is a basic write strategy 1, 2 in the system control unit 14 and the optical disc control unit 15. Store each in, 2.

By the command of recording, the system control unit 13 outputs a signal WR_STR_CON for controlling the recording pulse to the optical disc control unit 15, and the optical disc control unit 15 outputs a high frequency signal REF_Data in Tables 1,2. ) Is generated in accordance with the above recording pulse control signal WR_STR_CON and output to the recording unit 16.

The recording unit 16 emits light to the optical disc 10 at the optical pickup 11 with recording power by the recording pulse and the recording power control signal WR_POW_CON applied from the system control unit 14, thereby providing a desired high frequency. The signal REF_Data is recorded.

When the recording of the high frequency signal REF_Data on the optical disc 10 is completed, the high frequency signal recorded on the optical disc 10 is converted into an electrical signal by the amount of light reflected by the optical pickup 11 and reproduced by the reproducing unit 12. The data RD_Data is reproduced, and the reproduced data is stored in the reproduction data storage unit 13 as a square wave composed of a mark MARK and a space.

The data stored in the reproduction data storage unit 13 is output to the system control unit 14, and the reproduction data output from the reproduction unit 12 is input to the optical disc control unit 15 for recording completion or the like.

At this time, the system control unit 14 finds a constant pattern in which a length shift occurs from the reproduction data, and controls the recording unit 16 and the optical disc control unit 15 according to the degree in which the pattern appears.

To this end, the lengths of the marks to be compared are selected from the signals in Tables 1 and 2 of the high frequency signal as shown in FIG. 3, and the lengths of the previous space and the subsequent space of the marks are respectively determined.

That is, as shown in (a) and (b) of FIG. 5, Table 1 is a rising edge (RE) table and stores the relationship between the length of the mark and the length of the previous space, and Table 2 is the falling edge (FE) table. Since the relationship between the length of the mark and the length of the space afterwards is stored, the length of the mark and the space to be compared is determined in Table 1,2 (table1, table2).

The marks to be compared are compared with the playback data, respectively, and then detected an error pattern that may occur at the edges of the playback data, that is, the rising edge (RE) and the falling edge (FE). The recording power and the recording strategy of the recording unit 16 and the optical disc controller 15 are controlled according to the frequency of the same error pattern among the above error patterns.

To this end, the optical recording method according to the present invention will be described in detail with reference to the embodiment shown in Fig. 2 (2a, 2b).

First, the predetermined high frequency signal REF_Data is recorded and read, and the read data RD_Data is read from the reproduction data storage unit 13 (S11 and S12).

After the step S12, as shown in Fig. 3, the length of the mark to be compared (CURMARK-ｘ), the length of the previous space of the mark (PRESPACE-ｐ) and the length of the subsequent space (POSTSPACE-ｑ), the table of the high frequency signal (REF_Data) Determined from 1,2 respectively (S13). Here, ｘ, ｐ, ｑ means the length of the mark and space.

Here, in the DVD-RAM format, an error detection table of rising and falling edges (RE; Falling Edge) as shown in Tables 5 and 6 shown in FIG. And (c) and (d) of FIG. 5 are tables 3 and 4 to be updated for updating (Update write strategy Tables 1 and 2).

After the step S13, the high frequency signal and the reproduction data are compared with each other to detect an error pattern generated at the mark edge (S14). That is, if (a) of FIG. 4 is a mark to be recorded, an error pattern that may be generated from this mark may be represented by data such as (b) to (g).

Fig. 4A is a mark to be recorded and space before and after, where "RE" is a rising edge of the mark and "FE" represents a falling edge of the mark. Based on the mark edges RE and FE to be recorded, if the mark edges RE and FE to be compared are moved to the right, they are assigned a positive value, and if they are moved to the left, they are assigned a negative value. .

4 (b to g) enumerate error patterns that can be obtained from the reproduction data.

"-1" for each edge moved 1T to the left, "+1" for 1T moved to the right, and "0" if there is no movement. , (b) RE = -1, FE = 1, (c) RE = 1, FE = -1, (d) RE = 1, FE = 0, (e) RE = -1, FE = -1, (f) is assigned to RE = 0, FE = -1, and (g) is assigned to RE = 0, FE = -1.

From this error pattern, the error of the rising edge and falling edge of the mark to be compared is calculated and the length of the current mark (CURMARK-ｘ), the length of the previous space (PRESPACE-ｐ), the length of the subsequent space (POSTSPACE-ｑ) and the rising edge ( RE) and falling edge (FE) are updated in Tables 5 and 6.

To this end, it is determined whether the mark rising edge is RE = 1,0, -1 (S15), and then it is determined whether the falling edge is FE = 1,0, -1 (S16, S17, S18).

Here, when the error pattern of the mark edge is RE = -1, FE = 1, the recording power is small due to the asymmetry, and the mark is less recorded. The asymmetric negative (ASYMN) flag ASYMN of Tables 5 and 6 is 1 Increment by step (S16-1). That is, ASYMN = ASYMN + 1.

On the contrary, if the error pattern of the mark edge is RE = 1, FE = -1, it is caused by asymmetry. However, since the mark power is large because the recording power is large, the asymmetry positive (ASYMP) flag ASYMP of Tables 5 and 6 is suppressed. Increase by 1 (S18-2). That is, ASYMP = ASYMP + 1.

Further, if RE = 1 and FE = 0, the edge error pattern of the mark moves only up, the RE _ｘｐ of table 5 is increased by one (S18-1), and if RE = -1, FE = 0, the RE of table 5 is increased. decrease _ｘｐ by 1 (S16-2). That is, if RE = 1, FE = 0, RE _ｘｐ = RE _ｘｐ +1, and if RE = -1, FE = 0, it reflects RE _ｘｐ = RE _ｘｐ -1 in Table 5.

On the contrary, in the case of RE = 0 and FE = 1 where the edge error pattern of the mark moves only in the falling direction, FE _xｑ of Table 6 is increased by 1 (S17-1), and if RE = 0, FE = -1, _FEｘｑ is increased. 1 is reduced (S17-2). In other words, if RE = 0 and FE = 1, FE _ｘｑ = FE _ｘｑ +1, and if RE = 0 and FE = -1, FE _ｘｑ = FE _ｘｑ -1 will be reflected in Table 6.

On the other hand, in the case of RE = -1, FE = -1 and RE = 1, FE = 1, which move entirely without affecting the length of the mark, and in the case of RE = 0, FE = 0 without moving the length of the mark Not reflected in Tables 5 and 6.

Then, it is determined whether the end of the high-frequency signal (S19), if not the end to select the next comparison mark in the high-frequency signal (S20), and the length of the mark, the length of the previous space, the length of the subsequent space in the high-frequency signal By repeating step S13, the error values of the rising edge and the falling edge of the mark to be compared are updated in Tables 5 and 6 until the end of the high frequency signal.

According to the frequency and length variation of each error pattern in the tables 5 and 6 updated as described above, the recording conditions such as the recording power and the recording strategy are changed.

To this end, the absolute value of the asymmetrical negative flag (| ASYMN |) is compared with the first threshold (α) (S21). The recording power is adjusted to be small (e.g., 0.1 mW decrease) (S21-1), and a step (S11) of recording a high frequency signal is performed.

In addition, the absolute value of the asymmetric positive flag (| ASYMP |) is compared with the second threshold (β). If the second threshold value is larger than or equal to the second threshold value (S22), since the recording power is small and the mark is entirely asymmetric, the mark length is long. The recording power is adjusted so as to increase (for example, 0.1 mW increase) (S22-1), and a step (S11) of recording a high frequency signal is performed.

Here, the first threshold value α is a value for comparing a relatively high frequency of "ASYMN" flag, and the second threshold value (β) is a value for comparing a relatively high frequency of "ASYM \" flag.

After the step S22, if the absolute value of the asymmetric positive value is smaller than the second threshold value, the recording data of the optical disc is not asymmetrical due to the recording power but changes in the jitter according to the write strategy of the recording pulse. Step S11 is performed by changing the recording pulse.

Here, among the error patterns updated in Table 5, the absolute value (| RE _ｘｐ |) of the pattern RE _증 increasing / decreasing mark rising _edge is compared with the third threshold value r (| RE _ｘｐ > r) (S23). ), If the rising edge of the mark recorded as RE _ｘｐ > 0 or RE _ｘｐ <0 is frequently moved left / right when the third threshold value is exceeded, Table 3 (Write) stored in the optical disc storage unit 15 Update Strategy Table 3) (S23-1).

That is, if RE _ｘｐ > 0, the mark edge is moved to the left more frequently, so the delay amount of the start pulse of the recording pulse (i.e., when the rising edge starts) is increased (e.g., 1T), and if RE _이 <0 Since the rising edge of the recorded mark is frequently moved to the right, the starting pulse of the recording pulse output from the optical disk storage unit 15 to reduce the delay amount of the starting pulse among the recording pulses (for example, -1T). This reduces the amount of delay.

Similarly, the absolute value of the pattern (FE _xq) which is increased or decreased land to mark the falling out of the error patterns to update the table 6 _(| FE _{xq |)} compared to the fourth threshold (δ) and _{(| FE xq |> δ)} (S24 ), When the falling _edge of the mark recorded as FE _ｘｑ > 0 or FE _ｘｑ <0 is frequently moved left / right when the fourth threshold is exceeded, Table 4 stored in the optical disc storage unit 15 (Write). Update Strategy Table 4) (S24-1)

That is, if FE _ｘｑ > 0, the mark falling _edge is moved frequently to the left, so the delay amount of the end pulse of the recording pulse (that is, when the falling edge starts) is increased (eg, 1T), and FE _ｘｑ <0 When the rising edge of the recorded mark is moved to the right, the frequency of the recording pulse output from the optical disk controller 15 to reduce the delay amount of the ending pulse of the recording pulse (e.g. -1T) is increased. This causes the amount of delay to be reduced.

Subjected to a procedure such as the following, error pattern is shown in Tables _{5,6 | RE xp | ≤r & |} FE xq | ≤δ if not the procedure proceeds to the recording step _{(S11), | RE xp |} ≤r & | If FE _ｘｑ ≤ δ, it is determined that the recording pulse type is well selected when the mark edge is moved below the predetermined value (r, δ) during recording / reproduction. The update tables 3 and 4 (Update write strategy Tables 1 and 2) are updated from, 6 and transferred to the tables 1 and 2 of the optical disc controller 14 (S26).

As described above, the present invention detects the frequency of the occurrence of an error at an edge having a predetermined error pattern, and changes the recording conditions according to the frequency of the same pattern among the error patterns, thereby causing the characteristics and status according to the type of optical disc. According to different recording conditions, it is possible to record.

As described above, in the optical recording method according to the present invention, the error pattern of the high frequency signal is recorded / reproduced in advance, and then changed to an optimal recording condition according to the type or state of the disc, thereby recording the relationship between the type of the disc and the bending of the disc. There is always the effect of improving the reliability of the data by recording the data with the best jitter.

In addition, in the case of a high-density rewritable disc, if the disc manufacturer has a different recording pulse shape, the optical disc driver can take different recording pulse shapes, thereby preventing the problem of variation in recording / playback characteristics. There is.

Claims (10)

An error pattern generated by recording a predetermined high frequency signal and reproducing it is compared with the high frequency signal to detect an error pattern, and the recording conditions of the optical disc are changed according to the frequency of the detected error pattern. Optical recording method. The method of claim 1, And when the length variation of the data is an error pattern generated at both edges, the recording power is adjusted according to the frequency of the error pattern and the degree of variation in the length. The method of claim 1, And the recording pulse is adjusted according to the frequency of the error pattern and the degree of variation in the length when the length variation of the data is only one side of the error pattern. The method of claim 2, If the frequency of the variation that increases the length of the data on both the rising edge and the falling edge of the data is reduced the recording power, An optical recording method characterized by increasing the recording power when the frequency of the decrease of the data length on both the rising edge and the falling edge increases. The method of claim 3, wherein When the rising edge of the reproduced data has a large frequency of the data shifted to the left, the delay amount of the start pulse of the recording pulse is increased, And the start pulse delay amount of the recording pulse is reduced when the rising edge of the reproduced data is frequently shifted to the right. The method of claim 3, wherein The frequent error pattern of the data in which the falling edge of the reproduced data is shifted to the left increases the end pulse delay amount of the recording pulse, And an error pattern having a high frequency of data in which the falling edge of the reproduced data moves to the right reduces the delay amount of the end pulse of the recording pulse. The method of claim 1, And the error pattern distinguishes each error pattern according to a position and a moving distance of the length shift of the mark from the relationship with the space before and after the data adjacent to the mark. The method of claim 1, And the error pattern classifies each error pattern according to a position and a movement distance of the length of the space that is changed from the relationship with the front and rear marks adjacent to the data space. Recording and reproducing predetermined data to read the data; Determining a length of a mark and a space from a table in which the predetermined data is to be recorded, and detecting an error pattern for the length at rising and falling edges generated in the read data from the determined length; Updating a length variation of the detected error pattern in an error detection table; Adjusting a recording condition according to a frequency at which the same error pattern is updated among length variations updated in the error detection table; And And updating the updated error detection table in a basic table to be recorded. The method of claim 9, The recording condition adjustment is characterized in that the recording power is adjusted when the frequency of the error pattern having the length variation of both sides of the mark is high, and the recording strategy is adjusted when the frequency of the error pattern having the length variation only at one side of the mark is large. Optical recording method.