JP2004146043A - Light modulation recording and reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To set up the optimum recording pulse width parameter and recording power parameter within a short period of time, when information is recorded by light modulation using a standard recording condition stored on an optical disc or outputted from a device, by correcting a difference between the above standard recording condition and an optimization condition in actual recording. <P>SOLUTION: In order to correct the standard recording condition read from the optical disc or outputted from the device, the pulse width parameter is decided by performing writing tests with plural of the pulse width conditions regarding the pulse width parameter for irradiating the recording power to form a recording mark, and the recording parameter is decided by performing the writing tests with the plural of the recording power using the pulse width parameter decided by the above. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention sets a recording pulse width by reading setting information for determining recording conditions stored in a specific area of an optical recording medium such as an optical disk, or by outputting the setting information from within the apparatus, thereby setting a recording pulse width. The present invention relates to an optical modulation recording / reproducing apparatus which corrects recording conditions by performing recording / reproduction in a specific area for which conditions are required.

(2) Recordable DVDs such as DVDRAM, DVD-RW, and DVD-R have been developed and generally sold as optical disk devices for recording large amounts of data. In these optical disk devices, a pulse train that changes according to recording information is converted into a pulse train finer than the minimum unit of information, the laser beam is intensity-modulated by the fine pulse train, and the intensity-modulated laser beam is placed on a medium. The recording is performed by changing the physical characteristics of the medium by condensing and heating. Here, recording condition setting information for performing recording compensation such as a pulse width necessary for recording and power of each laser beam is stored in the optical disc in advance.

However, the recording condition setting information stored on the optical disc is formed on the substrate as ROM information, and thereafter, the disc (recording medium) is formed. Varies.

That is, even when information is recorded with the same power and the same pulse width, the size of the recorded mark / space changes depending on the structure of the recording medium, the composition of the recording film, the ambient temperature, and the like.

In particular, in high-density optical recording in which mark edge recording in which information is given to the edge of a mark / space is performed in a high density, a change in the length of the recorded mark / space in the track direction causes jitter of a reproduced signal. The error rate of the reproduced data is deteriorated.

Therefore, in an optical disk apparatus, test writing (test write) on an optical disk is usually performed, a recording state obtained from a reproduced signal is determined, and recording conditions are corrected as necessary.

Regarding the correction of the recording condition, there is the following publication as a conventional technique for optimizing a recording power parameter and a recording pulse width parameter.

方法 As a method for determining a recording power parameter to an optimum condition, for example, there are Patent Document 1 and Patent Document 2. According to this publication, recording is performed by changing various recording powers, and a function of γ = (Δm / m) / (ΔP / P) is obtained using a modulation degree m obtained from a reproduced signal and the recording power P. And a more optimal recording power parameter is determined.

Here, the modulation degree m is obtained by standardizing the reproduced data amplitude (the difference between the reproduced data peak level Pk and the reproduced data bottom level Bt) with the reproduced data peak level Pk, and (Pk−Bt) / It is represented by Pk.

方法 Further, as a method for correcting the recording pulse width parameter to an optimum condition, for example, there is Japanese Patent Application Laid-Open No. H11-163873. According to this publication, recording is performed by changing the recording pulse width parameter uniformly regardless of the recording mark length with respect to the standard recording conditions described on the optical disc, and using the jitter of a reproduction signal of the data to perform recording. Optimal recording conditions are determined.

Further, in Patent Document 4, a data table for adjusting a recording pulse corresponding to each recording mark is created using various patterns, and correction corresponding to all mark lengths is enabled.

Patent Document 5 discloses a method for optimizing the recording power parameter and the recording pulse width parameter, that is, for correcting all recording conditions for standard recording information recorded in advance on an optical disc.

According to this publication, the test write is repeated a number of times for each recording condition in order to determine various parameters, and the asymmetry (symmetry) of the reproduced signal of the test write data is detected and determined. Recording conditions are determined.
JP-A-9-138946 (Published date: May 27, 1997) Japanese Patent Application Laid-Open No. 11-134691 (release date: May 21, 1999) JP 2000-200418 A (Publication date: July 18, 2000) JP 2000-331348 A (publication date: November 30, 2000) Japanese Patent Laid-Open Publication No. 2002-25060 (Published date: January 25, 2002)

However, in the compensation of the recording conditions disclosed in Patent Document 1 and Patent Document 2, there is a problem that only the recording power parameter is set and the recording pulse width parameter is not corrected.

補償 In addition, in the compensation of the recording conditions described in Patent Documents 3 and 4, there is a problem that the recording power parameter is not determined.

Further, the recording compensation disclosed in Patent Document 5 requires a large amount of test writing area and a long time, and thus has a problem that it is unsuitable to be mounted on a commercially available recording and reproducing apparatus.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a standard recording condition previously stored on an optical recording medium such as an optical disk or output from a device side and an optimization condition for actual recording. And to determine the optimum recording pulse width parameter and recording power parameter in a short time.

In order to solve the above problems, the optical modulation recording / reproducing apparatus of the present invention performs optical modulation recording on an optical recording medium based on a recording pulse that changes according to recording information, and reproduces the recorded information. In the optical modulation recording / reproducing apparatus, test recording is performed on a predetermined area of the optical recording medium under a plurality of pulse width conditions with respect to the recording pulse, and a recording pulse width parameter of the recording pulse is corrected based on the reproduction result. It is characterized in that a correction means for performing test recording in the predetermined area with a plurality of recording powers using a recording pulse width parameter corrected as described above and determining a recording power parameter based on the reproduction result is provided. .

Further, in order to solve the above-mentioned problems, the optical modulation recording / reproducing apparatus of the present invention uses an optical recording medium in which recording power setting information and a recording pulse width parameter are stored, for recording pulses that change according to recording information. In an optical modulation recording / reproducing apparatus that performs optical modulation recording based on and reproduces recorded information, test recording is performed in a predetermined area of the optical recording medium under a plurality of pulse width conditions, and a recording pulse is generated based on the reproduction result. A correction unit that corrects the width parameter, performs test recording in the predetermined area with a plurality of recording powers using the recording pulse width parameter thus corrected, and determines a recording power parameter based on a reproduction result thereof. It is characterized by:

Further, in the optical modulation recording / reproducing apparatus of the present invention, recording power setting information including recording power parameter information and recording pulse width parameter information are previously stored in the optical recording medium. It is preferable that the correction means is configured to use the power setting information and the recording pulse width parameter information.

The optical modulation recording / reproducing apparatus according to the present invention further includes a data output unit that outputs recording power setting information including recording power parameter information and recording pulse width parameter information. It is preferable that the correction unit is configured to use the output power setting information and recording pulse width parameter information.

In addition, in the optical modulation recording / reproducing apparatus of the present invention, it is preferable that among the recording pulse width parameters, a parameter that affects the recording power parameter is corrected.

In the optical modulation recording / reproducing apparatus according to the present invention, it is preferable that the recording information is formed as a recording mark, and among the recording pulse width parameters, a parameter for changing a front edge portion of the recording mark is corrected.

In the optical modulation recording / reproducing apparatus of the present invention, it is preferable that the recording pulse is composed of a plurality of pulse trains, and the parameter is a pulse width of a start end of the recording pulse.

In the optical modulation recording / reproducing apparatus of the present invention, it is preferable that the recording information is formed as a recording mark, and among the recording pulse width parameters, a parameter for changing a width of the recording mark is corrected.

In the optical modulation recording / reproducing apparatus according to the present invention, it is preferable that the recording information is formed as a recording mark, the recording pulse is composed of a plurality of pulse trains, and a pulse width of an intermediate pulse in the pulse train is changed.

In the optical modulation recording / reproducing apparatus of the present invention, it is preferable that the correction unit determines the recording power parameter based on a plurality of trial recordings performed based on the recording power setting information.

In the optical modulation recording / reproducing apparatus of the present invention, it is preferable that the recording power setting information includes a modulation degree under a predetermined recording condition.

Further, in order to solve the above problems, the optical modulation recording / reproducing apparatus of the present invention performs optical modulation recording on an optical recording medium based on a recording pulse that changes according to recording information, and performs recording of the recorded information. In an optical modulation recording / reproducing apparatus for performing reproduction, after determining a recording power parameter of the recording pulse and a recording pulse width parameter affecting the recording power parameter, correcting a recording pulse width parameter not affecting the recording power parameter. For this purpose, a correction means for performing test recording on the optical recording medium under a plurality of pulse width conditions is provided.

Further, in the optical modulation recording / reproducing apparatus of the present invention, the recording pulse is composed of a plurality of pulse trains, and among the recording pulse width parameters that do not affect the recording power parameter, the pulse width of the pulse at the end of the recording pulse is corrected. Is preferred.

Further, in the optical modulation recording / reproducing apparatus of the present invention, the recording pulse is composed of a plurality of pulse trains, and among the recording pulse width parameters which do not affect the recording power parameter, the start position of the pulse at the beginning of the recording pulse is corrected Is preferred.

Further, in the optical modulation recording / reproducing apparatus of the present invention, the correction means performs test recording on a predetermined area of the optical recording medium at a plurality of recording powers using a predetermined recording pulse width parameter for the recording pulse. When the reproduction result satisfies the predetermined evaluation index, the recording power parameter is determined. When the reproduction result does not satisfy the predetermined evaluation index, the recording pulse width parameter is changed and test recording is performed again in the predetermined area with a plurality of recording powers. It is preferable that the recording power parameter is determined based on the result of the reproduction.

Further, in the optical modulation recording / reproducing apparatus of the present invention, recording power setting information including recording power parameter information and recording pulse width parameter information are stored in the optical recording medium in advance, and the correction unit includes: Preferably, the test recording is configured to use the recording power setting information and the recording pulse width parameter information.

Further, the optical modulation recording / reproducing apparatus of the present invention further includes a data output unit that outputs recording power setting information including recording power parameter information and recording pulse width parameter information, and the correction unit includes: It is preferable to use the power setting information and the recording pulse width parameter information output from the data output means.

As described above, the optical modulation recording / reproducing apparatus of the present invention performs test recording on a predetermined area of the optical recording medium under a plurality of pulse width conditions with respect to the recording pulse, and records the recording pulse of the recording pulse based on the reproduction result. The width parameter is corrected, test recording is performed on the predetermined area with a plurality of recording powers for the recording pulse using the recording pulse width parameter thus corrected, and the recording power parameter of the recording pulse is determined based on the reproduction result. Is provided.

According to the correction means, test recording is performed under a plurality of pulse width conditions, and the recording pulse width parameter is corrected first based on the reproduction result. As a result, the optimum recording pulse width condition can be realized. Note that other recording conditions such as recording power used for the test recording are based on, for example, information stored in the optical recording medium or information output from the optical modulation recording / reproducing apparatus.

Next, test recording is performed on the optical recording medium with a plurality of recording powers using the corrected recording pulse width parameter, and the recording power parameter is determined. As a result, test recording with a plurality of recording powers is performed in a state where the recording pulse width parameter is optimized, a large amount of test recording and an area for the recording are not required, and the recording power parameter can be efficiently determined. The recording power can be optimized in a short time.

This makes it possible to always keep the recording conditions of the optical modulation recording / reproducing apparatus in an optimum state.

As described above, the conditions other than the corrected recording conditions used for the test recording are the recording power setting information including the recording power parameter information and the recording pulse width parameter information stored in advance on the optical recording medium. And may be based on Further, a data output means for outputting these may be provided, and the data output means may be based on the power setting information and the recording pulse width parameter information output from the data output means.

Further, the optical modulation recording / reproducing apparatus of the present invention performs test recording on a predetermined area of the optical recording medium under a plurality of pulse width conditions, and corrects a recording pulse width parameter based on the reproduction result. A correction means is provided for performing test recording in the predetermined area with a plurality of recording powers using the recording pulse width parameter obtained, and determining a recording power parameter based on the reproduction result.

According to the above configuration, when the optical recording medium is mounted on the optical modulation recording / reproducing apparatus, the recording power parameter and the recording pulse width parameter are read out, and based on these parameters, the optimum recording power and the optimum recording power are determined. Information to be recorded is written to the optical recording medium with the pulse width.

However, at this time, the recording conditions obtained from the above parameters do not always match the characteristics of the optical recording medium, and therefore the optical modulation recording / reproducing apparatus is not always under the optimum recording conditions.

Therefore, according to the optical modulation recording / reproducing apparatus, a correcting means is provided to solve the above-mentioned problem. The correction means performs test recording on a predetermined area of the optical recording medium under a plurality of pulse width conditions, and corrects a recording pulse width parameter based on a reproduction result. Thereby, the recording pulse width parameter is corrected, and the optimum pulse width condition of the recording pulse can be realized.

{Circle around (4)} The correcting means performs test recording in the predetermined area with a plurality of recording powers using the recording pulse width parameter corrected as described above, and determines a recording power parameter based on the reproduction result.

That is, test recording is performed in the predetermined area with a plurality of recording powers with the recording pulse width parameter being optimized. Therefore, a large amount of test recording and an area for the test recording are not required, and the recording power parameter is determined efficiently, so that the recording power can be optimized in a short time. This makes it possible to always keep the recording conditions of the optical modulation recording / reproducing apparatus in an optimal state.

Further, as described above, when a parameter that affects the recording power parameter among the recording pulse width parameters is corrected, a parameter that does not affect the recording power parameter among the recording pulse width parameters is corrected. Will be excluded. As a result, the recording conditions can be optimized with a shorter time and a smaller recording area.

Further, as described above, when the parameter to be corrected is a parameter that changes the leading edge of a recording mark (such a parameter includes a pulse width of a start end of a recording pulse composed of a plurality of pulse trains). Thus, it is possible to obtain a recording pulse having a pulse width in which the instability of the recording mark head is eliminated.

As described above, the recording information may be formed as a recording mark, and among the recording pulse width parameters, a parameter that changes the width of the recording mark may be corrected. Alternatively, the recording information may be formed as a recording mark, and the recording pulse may be composed of a plurality of pulse trains, and a pulse width of a middle pulse in the pulse train may be changed. This is because if the width of the recording mark is too narrow, it becomes difficult to recognize the recording mark at the time of reproduction, and if the width of the recording mark is too wide, an adjacent track may be adversely affected. In this regard, according to the above configuration, it is possible to obtain a recording pulse having a pulse width that eliminates the instability of the latter half of the recording mark.

Further, as described above, when determining the recording power parameter based on a plurality of test recordings performed based on the recording power setting information, even if the test recording is performed based on the recording power setting information, Since the recording pulse width parameter is optimally corrected, the optimum recording power can be set without any problem.

Further, as described above, when the recording power setting information includes a modulation degree under a predetermined recording condition, a recording power parameter is determined using the modulation degree under a predetermined recording condition, and an optimum power based on the recording power setting information is determined. Recording power can be set.

Further, as described above, the optical modulation recording / reproducing apparatus of the present invention determines the recording power parameter of the recording pulse and the recording pulse width parameter affecting the recording power parameter, and then influences the recording power parameter. In order to correct a non-recording pulse width parameter, a correction means for performing test recording on the optical recording medium under a plurality of pulse width conditions is provided.

According to the above configuration, first, the recording power parameter of the recording pulse and the recording pulse width parameter that affects the recording power parameter are determined, and then the recording pulse width parameter that does not affect the recording power parameter is corrected. Things.

Therefore, in the determination of the recording power parameter and the recording pulse width parameter that affects the recording power parameter, the determination (correction) order does not affect the recording power parameter even if the recording power parameter is determined first. The recording pulse width parameter to be given may be determined first. Further, the determination (correction) method is not limited. That is, any method may be used as long as the recording power parameter and the recording pulse width parameter affecting the recording power parameter can be optimized under recording conditions.

The recording pulse width parameters that do not affect the recording power parameter include the pulse width of the pulse at the end of the recording pulse and the start position of the pulse at the beginning of the recording pulse.

Here, in high-density optical recording in which mark edge recording is frequently performed, a change in the position of a recorded mark / space in the track direction as described above causes jitter of a reproduced signal, and an error rate of reproduced data. Increase.

If the pulse width at the end is shifted, the erase power is applied after the pulse at the end, the mark after the pulse at the end is erased, the length of the recording mark changes, and the length after the recording mark is changed. The edge position changes. Further, even when the start position of the pulse at the start end is shifted, the front edge position of the recording mark changes, and the length of the recording mark also changes.

In this regard, according to the above configuration, it is possible to match the duties of the recording mark / space after optimizing the recording power parameter. In addition, since the recording pulse width parameter that does not affect the recording power parameter is corrected last, it is possible to determine the final recording / reproducing state. Based on the result of this determination, it is determined that the desired performance is not satisfied. In this case, it is possible to determine whether or not a series of recording condition corrections are to be performed again by test recording in different areas of the optical recording medium.

Further, as described above, test recording is performed on a predetermined area of the optical recording medium with a plurality of recording powers using a predetermined recording pulse width parameter for a recording pulse, and when a reproduction result satisfies a predetermined evaluation index, recording is performed. When the power parameter is determined and the predetermined evaluation index is not satisfied, the recording pulse width parameter is changed and test recording is performed again in the predetermined area with a plurality of recording powers, and the recording power parameter is set based on the reproduction result. You may decide.

The above configuration sets a predetermined recording pulse width parameter, performs test recording on the optical recording medium with a plurality of recording powers by fixing the parameter, and sets a recording power parameter when a reproduction result satisfies a predetermined evaluation index. If it is determined that the predetermined evaluation index is not satisfied, the recording pulse width parameter is changed. In this case, when the predetermined recording pulse width parameter initially set substantially satisfies the optimum condition at the time of actual recording, the recording power parameter can be efficiently determined, and the time and test time required for test recording can be determined. The area for recording can be further reduced.

As described above, the recording conditions such as the predetermined recording pulse width parameter used for each of the test recordings include the recording power setting information including the recording power parameter information and the recording pulse width stored in advance on the optical recording medium. It may be based on parameter information. Further, a data output means for outputting these may be provided, and the data output means may be based on the power setting information and the recording pulse width parameter information output from the data output means.

[Embodiment 1]
An embodiment of the present invention will be described below with reference to FIGS.

FIG. 2 is a schematic block diagram of an optical modulation recording / reproducing apparatus for correcting recording conditions of an optical disk having information for setting recording conditions according to the present invention to optimal recording conditions.

As shown in FIG. 2, the optical modulation recording / reproducing apparatus includes a phase change type optical disk (optical storage medium) 1 capable of recording data, a motor 2 for rotating the optical disk 1, and a data And an optical pickup 3 for recording / reproducing. The optical pickup (PU) 3 irradiates a specific track of the optical disc 1 with a beam spot using a servo system (not shown). Recording / reproducing to / from the optical disc 1 is performed by a beam spot from the optical pickup 3, and the optical pickup 1 moves in the radial direction of the optical disc, thereby enabling recording / reproducing on the entire area of the optical disc.

On the inner circumference side of the optical disc 1, there is an information area in which information necessary for recording / reproduction including information for setting recording conditions is stored, and a test recording for setting recording conditions (hereinafter referred to as a test write). ) Is also formed. The data recording / reproducing area on the optical disc 1 is set on the outer peripheral side of the area, and a format different from the information area in the form of information, frequency band, and the like is used.

Here, information (recording power setting information and recording pulse width parameter information including standard recording conditions and recording power parameter information) necessary for recording / reproduction including information for setting the recording conditions is transmitted to the optical modulation recording / reproducing apparatus. May be output.

(4) The optical modulation recording / reproducing apparatus reproduces the information area of the optical disc 1 and obtains setting information for optimal recording / reproduction. The optical disk information reproducing circuit 4 performs a waveform process on the signal reproduced from the optical pickup 3 and sends a binarized signal to a recording / reproducing operation control circuit 5 (data output means). In the recording / reproducing operation control circuit 5, standard recording conditions are determined using information stored in the optical disc 1.

In the recording of information, as shown in FIG. 3, the information to be recorded on the optical disk 1 is converted by the recording information processing circuit 6 so as to be suitable for recording on the optical disk. The generation circuit 7 generates a recording pulse obtained by converting a pulse train that changes in accordance with the recording information into a pulse train finer than the minimum unit of information, and the laser driving circuit 8 generates predetermined recording pulses, recording power, erasing power, and bias power for each pulse. A recording mark is formed on the optical disc 1 by generating a current serving as a laser power and driving the laser element of the optical pickup 3.

(4) A recording pulse in such an optical modulation recording / reproducing apparatus is a pulse train that changes according to information to be recorded, as shown in FIG. 4, and a heat distribution of a medium temperature is taken into consideration for recording on an optical disk. The recording information has different lengths of, for example, 2T to 8T, and is constituted by a pulse having a start portion and an end portion, and a recording pulse having a length of 3T or more having an intermediate portion formed of a plurality of pulse trains. Is converted to a recording pulse. Then, the recording pulse width stored in the optical disk is read, a predetermined pulse width is determined in the recording / reproduction operation control circuit 5, and the pulse width is set in the recording pulse generation circuit 7.

に お い て In such a recording pulse, if the pulse width at the start end is shifted, the shape at the head of the recording mark will change. This is because the laser energy applied to the medium changes as the pulse width changes. That is, if the pulse width at the start end is too wide, the head of the recording mark swells and the mark width at the front edge changes. Conversely, if the pulse width at the start end is too narrow, the pulse width changes so that the leading edge width of the recording mark becomes smaller.

Similarly, when the pulse width in the middle part is too wide, the recording mark in the latter half of the recording mark expands, and the width of the recording mark increases. Conversely, if the pulse width in the middle part is too narrow, the number of the recording marks in the latter half of the recording marks decreases, so that the width of the recording marks decreases.

As described above, each of the recording pulse width parameters has a great influence on the recording mark shape (recording power parameter).

(4) If the pulse width at the end is shifted, the position of the trailing edge of the recording mark changes. This is because the erasing power is applied after the pulse at the end portion, so that the mark after the pulse at the end portion is erased, and the length of the recording mark changes. If the start position of the pulse at the start end is shifted, the front edge position of the recording mark changes, and the length of the recording mark changes. That is, the above-described recording pulse width parameters, that is, the pulse width at the end portion and the start position of the pulse at the start end portion, greatly affect the length of the recording mark.

In setting the recording power given by the laser drive circuit 8 with respect to this recording pulse, as described in detail in FIG. 1, the recording pulse is obtained through several trial recordings using information stored on the optical disk 1. The recording / reproducing operation control circuit 5 determines the modulation power of the reproducing signal, and sets the recording power parameter based on the information.

{Circle around (1)} In reproducing information, the information recorded on the optical disk 1 is extracted by the optical pickup 3. In the RF amplifier 9, a reproduced signal is synthesized from a plurality of pickup output signals and adjusted to an amplitude suitable for the input level of the next stage circuit. The reproduction signal outputs the information digitized by the binarization circuit 11 after the frequency characteristic is corrected by the equalization circuit 10.

The output of the equalization circuit 10 is also sent to the PLL circuit 12, which generates a reproduction clock synchronized with the reproduction signal, and is used by the reproduction signal evaluation circuit 13 as a reference timing required for reproduction.

(4) The reproduction signal evaluation circuit 13 outputs the performance evaluation result of the reproduction signal based on the error rate to the recording / reproduction operation control circuit 5.

In such an optical modulation recording / reproducing apparatus, when an optical disk is detected after the power is turned on or when a new optical disk is inserted, the recording conditions obtained from the information for setting the recording conditions of the optical disk and the optical disk medium characteristics match. And the recording conditions are not always optimal.

Particularly, when the recording pulse width parameter deviates from the optical disk medium characteristic, the shape of the recording mark becomes unstable as described above, which greatly affects the test write for determining the recording power parameter.

5 (a) and 5 (b) are the results of measuring the modulation of the reproduced signal when the pulse width of the recording pulse deviates from the optimum pulse width. Here, regarding the symbols used in FIGS. 5A and 5B and FIGS. 6A and 6B, Ttop is the pulse width at the beginning, Tmp is the pulse width at the middle, and Tend is the pulse at the end. Expressed in width.

FIG. 5A shows the effect when the recording pulse width parameters (the width of the pulse at the start end and the width of the pulse at the middle portion) for irradiating the recording power for forming the recording mark are shifted. FIG. 5A shows that the change in the modulation factor when the pulse width is shifted by ± 1 nS is different from the change in the modulation factor obtained by changing the recording power with the optimum pulse width. This means that when the recording power is determined using the modulation factor, the recording power for the predetermined modulation factor can be uniquely determined, but when the recording pulse width is shifted, the set recording power is determined. The power will not be the optimum recording power. In particular, since the change in the modulation factor when the pulse width is insufficient is significantly different from the case where recording is performed with the optimum pulse width, it can be seen that even if the test write is performed under such conditions, the recording power greatly deviates from the optimum recording power. .

(5) Next, FIG. 5B shows a change in the degree of modulation when the pulse width at the terminal end is shifted.

(4) The width of the recording mark does not change with respect to the pulse width deviation at the terminal end, so that it does not affect the reproduction signal amplitude. For this reason, the modulation degree shows the same change with respect to the change in the pulse width at the terminal end, and it is considered that there is no influence on OPC (Optimum Power Control) which is a process for setting the recording power parameter.

6 (a) and 6 (b) show the error rate conditions under the above conditions. It can be seen that in the state where the recording pulse width is shifted, the reproduction performance is deteriorated due to the deterioration of the recording state.

FIG. 6 (a) shows the effect of a shift in the pulse width (recording pulse width parameter) between the start and middle portions of the recording pulse width for irradiating the recording power. FIG. 6A shows that the change in error rate when the pulse width is shifted by ± 1 nS is different from the change in error rate obtained by changing the recording power with the optimum pulse width. The reproduced signal of the recorded information indicates that the recording state has deteriorated. In particular, the change in the error rate when the pulse width is insufficient is much worse than when the recording is performed with the optimum pulse width, and it can be seen that a sufficient recording mark is not formed.

FIG. 6B shows a change in the error rate when the pulse width at the terminal end is shifted.

The error rate is also deteriorated with respect to the pulse width deviation at the end part, and even if the recording power set by OPC using the modulation factor is appropriate, if the pulse width at the end part deviates, appropriate recording is performed. It can be seen that no mark is formed.

Here, the correction of the recording condition of the present invention will be described with reference to FIGS.

First, in the optical modulation recording / reproducing apparatus as shown in FIG. 2, when a new optical disc 1 is inserted, the optical pickup 3 moves to the innermost side and the motor 2 rotates. On the innermost circumference, the optical pick 3 performs focus and tracking servo to perform reproduction from the optical disc 1. Information for recording and reproducing the optical disk 1 is stored in the innermost peripheral portion of the optical disk 1, and the apparatus is controlled to start up based on the information. Here, a test write to the optical disc is performed during this start-up control. Since recording is not always performed when an optical disk is inserted, a test write may be performed after the first recording operation instruction after the optical disk is inserted.

In response to the test write operation instruction, the recording / reproducing operation control circuit 5, as shown in FIG. 1, sets the standard recording conditions from the optical disc 1 and the recording pulses Ttop (the width of the pulse at the start end), Tmp ( A recording condition in which the width of the pulse at the intermediate portion is changed is prepared (S1).

(4) Recording on the optical disk 1 is performed by changing Ttop and Tmp for each data recording unit (sector) of the optical disk (S2). Then, the recording data is reproduced by the binarization circuit 11, the reproduction signal is evaluated by the reproduction signal evaluation circuit 13, and the performance evaluation result is sent to the recording / reproduction operation control circuit 5 for determination (S3 to S4). As a criterion, the error rate is set to be the smallest (the number of errors is small), and Ttop and Tmp are determined based on the result (S5).

As a result, the pulse width related to the formation of the recording mark is optimized, and as shown in FIG. 5A, the condition that satisfies the modulation degree at low recording power caused by the pulse width that is too wide can be excluded. Further, a condition that satisfies the modulation factor at a high recording power, which is caused by the shortage of the pulse width, can be excluded. Therefore, the test write performed in the next stage functions normally, and the optimization of the recording power parameter is guaranteed.

Next, the recording power is determined by executing the test write with the recording pulse width parameter optimized, using the recording conditions obtained by correcting Ttop and Tmp with respect to the standard recording conditions. The recording power setting information stored on the optical disc for performing OPC includes a predetermined power Pref lower than the optimum recording power, a value of a modulation degree mref obtained by recording / reproducing when Pref is set as the recording power, and recording. The ratio of power to Pref (recording power coefficient), the ratio of erasing power to recording power (erasing power coefficient) and the ratio of bias power to recording power (bias power coefficient) are described several times in the test write area of the optical disk. By performing the recording / reproduction evaluation of, the three power conditions of recording power, erasing power, and bias power can be determined.

That is, the recording power Pref 'which is equal to the modulation degree obtained by recording / reproducing on the inserted optical disc 1 is obtained (S6 to S8). As a result, Pref 'for obtaining the recording power at which the degree of modulation mref is recorded on the optical disc 1 is obtained. The optimum recording power can be determined by multiplying this Pref ′ by the recording power coefficient, and similarly, the erasing power coefficient and the bias power coefficient can be determined for the erasing power and the bias power (S9 to S10). .

Accordingly, the recording power parameter can be determined based on a plurality of test recordings performed based on the recording power setting information. In this case, even if test recording is performed based on the recording power setting information, the optimum recording power can be set without any problem because the recording pulse width parameter has already been optimally corrected. The method of the present OPC is not limited to this, and various methods can be used. For example, a method of determining using a γ value as shown in the conventional example may be used.

Next, the width of the pulse at the end is corrected using Ttop, Tmp, and the recording conditions for which the recording power parameters have been determined. For each data recording unit (sector) of the optical disk, the recording is performed by changing Tend (pulse width of the end portion) (S11).

{Circle around (2)} The recorded data is reproduced by the binarization circuit 11, the reproduced signal is evaluated by the reproduced signal evaluation circuit 13, and the performance evaluation result is sent to the recording / reproduction operation control circuit 5 for determination (S12 to S13). Then, a state in which the error rate is the smallest is set as a determination criterion, and Tend is determined based on the determination result (S14). Thus, the recording mark can be set to a predetermined length, so that a good recording mark with a small duty shift can be formed.

Since the correction of the pulse width at the end portion determines the position of the end edge of the recording mark in the formation of the recording mark due to the change in the pulse width at the end portion, it is determined based on the symmetry (asymmetry) with respect to the intermediate level of the reproduction signal. You can also.

Next, a process of correcting the start position dTtop of the pulse at the start end using the recording conditions in which Ttop, Tmp and the recording power parameter are determined will be described with reference to FIG. Here, FIG. 7 shows each correction process of the start position dTtop of the pulse at the start end.

As shown in the figure, in the correction step of the start position dTtop of the pulse at the start end, first, the start position dTtop of the pulse at the start end is changed and recorded for each data recording unit (sector) of the optical disk (S21). .

Next, the recording data is reproduced by the binarization circuit 11 (S22), the reproduction signal is evaluated by the reproduction signal evaluation circuit 13, and the performance evaluation result is sent to the recording / reproduction operation control circuit 5 for determination. (S23).

Then, the state with the smallest error rate is used as a criterion, and dTtop is determined based on the determination result (S24).

Through the above steps, the recording mark can be set to a predetermined length, so that a good recording mark with a small duty shift can be formed.

FIG. 8 shows the effect of a shift in the start position dTtop of the pulse at the start end (the unit [nS] on the horizontal axis in FIG. 8 means a position shift of dTtop for nS). At this time, the pulse width Ttop at the start end is a fixed value. As shown in the drawing, when the start position dTtop of the pulse at the start end deviates from the optimum start position (0) by ± 1 nS, the error rate increases significantly, and the start position dTtop of the pulse at the start end is increased. The recording condition is degraded by the shifted recording condition.

Here, the correction of the start position of the pulse at the start end determines the position of the leading edge of the record mark in the formation of the record mark due to the change in the start position of the pulse at the start end. (Asymmetry).

補正 By the above processing, the correction for the standard recording condition stored on the optical disk is completed, and by performing the correction of the recording condition, it is possible to perform a good recording for forming an appropriate recording mark on the optical disk 1.

[Embodiment 2]
Another embodiment of the present invention will be described below with reference to FIG.

Note that, for convenience of explanation, members having the same functions as the members described in the above embodiment are denoted by the same reference numerals, and description thereof is omitted.

In the above-described embodiment, in order to optimize the recording condition in a short time and a small recording area, of the recording pulse width parameters, after correcting a parameter affecting the recording power parameter, the recording power parameter is corrected. A decision was made.

In the present embodiment, information (recording power setting information and recording pulse width parameter information including recording power parameter information) stored on the optical disc 1 (see FIG. 2) or output from the optical modulation recording / reproducing apparatus itself is used. Based on this, a recording pulse width parameter affecting the recording power parameter is set to a predetermined value, the recording power is changed while the recording pulse width parameter is fixed, and the recording power parameter is determined. Of the recording pulse width parameter which does not affect the recording pulse width. If the recording power parameter cannot be optimized with the above-mentioned predetermined value, the value of the recording pulse width parameter is changed and the same process is repeated. This makes it possible to optimize the recording conditions in a shorter time and with a smaller recording area.

Here, in the present embodiment, first, a recording pulse width parameter and a recording power parameter that affect the recording power parameter are determined (corrected), and then a recording pulse width parameter that does not affect the recording power parameter is determined ( to correct.

Therefore, in the determination (correction) of the recording power parameter and the recording pulse width parameter that affects the recording power parameter, the determination (correction) order may be any order. The determination (correction) of the recording power parameter may be performed first, or the determination (correction) of the recording pulse width parameter affecting the recording power parameter may be performed first.

Furthermore, the determination method is not limited to the above configuration. Any determination (correction) method may be used as long as the recording pulse width parameter and the recording power parameter that affect the recording power parameter can be optimized under the conditions at the time of recording.

Hereinafter, each correction (decision) process in the present embodiment will be described with reference to FIG.

As shown in the figure, first, in response to a test write operation instruction, the recording / reproducing operation control circuit 5 (see FIG. 2) transmits standard recording conditions (recording power setting information including recording power parameter information and recording pulse) from the optical disc 1. The width parameter information) is read, and recording conditions in which the recording pulse Ttop (the width of the pulse at the start end) and Tmp (the width of the pulse at the intermediate portion) for forming the recording mark are changed are prepared (S31).

In recording onto the optical disc 1, first, Ttop and Tmp (predetermined recording pulse width parameters) read from the optical disc 1 are set (S32).

Next, the test write is executed with the recording power changed while the recording pulse width parameter is fixed (S33).

{Circle around (4)} The reproduced data is subjected to the reproduction signal evaluation by the reproduction signal evaluation circuit 13, and the performance evaluation result is sent to the recording / reproduction operation control circuit 5 (S34). Then, the determination is performed based on the state where the error rate has a predetermined value (predetermined reproduction signal evaluation index, predetermined evaluation index) (S35). If the result of this determination is good, Ttop, Tmp and the recording power at that time are determined as optimal recording conditions (S38).

On the other hand, if it is determined in S35 that the result of determination is bad, if all the conditions for changing the recording power have not been used (S36), the process returns to S33. In S36, if all the conditions are used, Ttop and Tmp are changed in S37 (at this time, the recording conditions prepared in S31 can be used), and the process returns to S33 to change the recording power again. And execute the test light.

Next, using the determined recording conditions of Ttop, Tmp and the recording power parameter, the recording pulse width parameter Tend (hereinafter, referred to as the recording pulse width parameter Tend) which is the recording pulse width parameter that does not affect the recording power parameter. (Referred to as a pulse width at the end portion) (refer to S39 and thereafter).

First, recording is performed by changing the pulse width Tend of the end portion for each data recording unit (sector) of the optical disk (S39).

The recorded data is reproduced by the binarizing circuit 11 (S40), the reproduced signal is evaluated by the reproduced signal evaluation circuit 13, and the performance evaluation result is sent to the recording / reproduction operation control circuit 5. The judgment is made based on the smallest state (raw signal evaluation index best condition) (S41). Then, Tend is determined based on the result of this determination (S42).

According to the above, the recording mark can be set to a predetermined length, and as a result, a good recording mark with a small duty shift can be formed.

After determining Ttop, Tmp and the recording power parameter, the start position dTtop of the pulse at the start end (the recording pulse width parameter that does not affect the power parameter) may be corrected. The correction process itself in this case is the same as the above-described correction of the pulse width Tend of the terminal portion.

By the above processing, the recording pulse width parameter that influences the recording power parameter among the parameters is set to a predetermined value to determine the recording power parameter, and thereafter, the recording pulse width that does not affect the recording power parameter is determined. By correcting the parameters, the recording conditions can be optimized in a shorter time and in a smaller recording area.

In the above description, the case where the error rate is used for the evaluation of the reproduced signal in the setting of the recording pulse width parameter is exemplified. However, the present invention is not limited to this, and other methods such as jitter Can also be evaluated.

In the above description, the case where standard recording conditions (recording power setting information including recording power parameter information and recording pulse width parameter information) are stored in the optical disc 1 in advance, but the present invention is not limited to this. The standard recording conditions may be output on the optical modulation recording / reproducing apparatus side, and based on the output, test recording may be performed by changing the recording pulse width parameter and the recording power parameter, and optimization (correction and determination) may be performed. Absent.

As described above, in the optical modulation recording / reproducing apparatus of the present invention, it is possible to correct the pulse width for irradiating the recording power for forming the recording mark with respect to the standard recording condition stored on the optical disc. . Thereby, in the OPC for determining the recording power to be performed in the next stage, the recording power condition can be appropriately set. Further, by correcting the remaining end pulse width, all recording conditions for forming a recording mark are corrected. Therefore, all recording conditions can be adjusted to optimal values, and good recording can be ensured.

The present invention is applicable to an optical modulation recording / reproducing apparatus that performs optical modulation recording on an optical recording medium based on a recording pulse that changes according to recording information and reproduces the recorded information.

5 is a flowchart illustrating a correction process for optimizing a recording condition according to the embodiment of the present invention. FIG. 1 is a block diagram illustrating a configuration of an optical modulation recording / reproducing device according to the present invention. FIG. 3 is an explanatory diagram illustrating a recording pulse in the present invention. FIG. 4 is a waveform chart showing an example of a recording pulse used in the present invention. (A) is a graph showing the influence of the shift of the recording power pulse width (recording pulse) on the modulation degree.

(B) is a graph showing the influence of the end pulse width (recording pulse) deviation on the modulation degree.
(A) is a graph showing the influence of the recording power pulse width (recording pulse) deviation on the recording / reproducing performance.

(B) is a graph showing the influence of the end pulse width (recording pulse) deviation on the recording / reproducing performance.
6 is a flowchart illustrating a pulse correcting process of a terminal portion according to the present invention. 5 is a graph showing the influence of the displacement of the start end of the recording pulse on the recording / reproducing performance in the present invention. 9 is a flowchart illustrating a correction process for optimizing recording conditions according to another embodiment of the present invention.

Explanation of reference numerals

1 optical disk (optical recording medium)
2 Motor 3 Optical pickup (correction means)
5. Recording / reproduction operation control circuit (correction means, data output means)
7. Recording pulse generation circuit (correction means)
8 Laser drive circuit (correction means)
11 Binarization circuit (correction means)
13. Reproduction signal evaluation circuit (correction means)

Claims (17)

For an optical recording medium, an optical modulation recording and reproducing apparatus that performs optical modulation recording based on a recording pulse that changes in accordance with recording information and reproduces the recorded information.
Test recording is performed on a predetermined area of the optical recording medium under a plurality of pulse width conditions with respect to the recording pulse, and a recording pulse width parameter of the recording pulse is corrected based on a reproduction result thereof. An optical modulation recording / reproducing apparatus, comprising: correction means for performing test recording in the predetermined area with a plurality of recording powers using parameters and determining a recording power parameter based on the reproduction result. Optical modulation recording / reproduction that performs optical modulation recording on an optical recording medium on which recording power setting information and a recording pulse width parameter are stored based on a recording pulse that changes according to the recording information, and reproduces the recorded information. In the device,
Test recording is performed on a predetermined area of the optical recording medium under a plurality of pulse width conditions, and a recording pulse width parameter is corrected based on a result of the reproduction, and a plurality of recording powers are set using the corrected recording pulse width parameter. The optical modulation recording / reproducing apparatus further comprises a correction means for performing test recording in the predetermined area and determining a recording power parameter based on the reproduction result. The optical recording medium stores recording power setting information and recording pulse width parameter information including recording power parameter information in advance,
2. The optical modulation recording / reproducing apparatus according to claim 1, wherein the correction unit is configured to use the power setting information and the recording pulse width parameter information for each of the test recordings. Data output means for outputting recording power setting information and recording pulse width parameter information including recording power parameter information,
2. The optical device according to claim 1, wherein the correction unit is configured to use power setting information and recording pulse width parameter information output from the data output unit for each of the test recordings. 3. Modulation recording / reproducing device. 3. The optical modulation recording / reproducing apparatus according to claim 1, wherein a parameter that affects the recording power parameter among the recording pulse width parameters is corrected. 3. The optical modulation recording / reproducing apparatus according to claim 1, wherein the recording information is formed as a recording mark, and among the recording pulse width parameters, a parameter for changing a front edge portion of the recording mark is corrected. . 7. The optical modulation recording / reproducing apparatus according to claim 6, wherein the recording pulse includes a plurality of pulse trains, and the parameter is a pulse width of a start end of the recording pulse. 3. The optical modulation recording / reproducing apparatus according to claim 1, wherein the recording information is formed as a recording mark, and among the recording pulse width parameters, a parameter for changing a width of the recording mark is corrected. 3. The optical modulation recording / reproducing method according to claim 1, wherein the recording information is formed as a recording mark, and the recording pulse is composed of a plurality of pulse trains, and a pulse width of an intermediate pulse in the pulse train is changed. apparatus. The light according to any one of claims 2 to 4, wherein the correction unit determines the recording power parameter based on a plurality of trial recordings performed based on the recording power setting information. Modulation recording / reproducing device. 11. The optical modulation recording / reproducing apparatus according to claim 10, wherein the recording power setting information includes a modulation degree under a predetermined recording condition. For an optical recording medium, an optical modulation recording and reproducing apparatus that performs optical modulation recording based on a recording pulse that changes in accordance with recording information and reproduces the recorded information.
After determining the recording power parameter of the recording pulse and the recording pulse width parameter that affects the recording power parameter, in order to correct a recording pulse width parameter that does not affect the recording power parameter, a plurality of pulse width conditions are used. An optical modulation recording / reproducing apparatus, comprising a correction unit for performing test recording on an optical recording medium. 13. The light according to claim 12, wherein the recording pulse is composed of a plurality of pulse trains, and corrects the pulse width of the pulse at the end of the recording pulse among the recording pulse width parameters that do not affect the recording power parameter. Modulation recording / reproducing device. 13. The light according to claim 12, wherein the recording pulse includes a plurality of pulse trains, and corrects a start position of a pulse at a start end of the recording pulse among recording pulse width parameters that do not affect a recording power parameter. Modulation recording / reproducing device. The correction means performs test recording on a predetermined area of the optical recording medium with a plurality of recording powers using a predetermined recording pulse width parameter for the recording pulse, and when the reproduction result satisfies a predetermined evaluation index, the recording power When the parameters are determined and the predetermined evaluation index is not satisfied, the recording pulse width parameter is changed and test recording is performed again in the predetermined area with a plurality of recording powers, and the recording power parameter is determined based on the reproduction result. The optical modulation recording / reproducing apparatus according to claim 12, wherein the optical modulation recording / reproducing apparatus is configured to perform the operation. In the optical recording medium, recording power setting information including recording power parameter information and recording pulse width parameter information are stored in advance,
16. The optical modulation recording / reproducing apparatus according to claim 15, wherein the correction unit is configured to use the recording power setting information and the recording pulse width parameter information for each test recording. Data output means for outputting recording power setting information and recording pulse width parameter information including recording power parameter information,
16. The optical modulation apparatus according to claim 15, wherein the correction unit is configured to use the power setting information and the recording pulse width parameter information output from the data output unit for each test recording. Recording and playback device.

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