JP2005166202A - Recording condition setting method and setting device, recording and reproducing device, recording condition setting program and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a writable recording condition setting method and setting device, which form an excellent recording mark even when a time unit (1ns, for instance) for recording pulse width setting recorded on an optical disk, and a setting time unit (2ns, for instance) in an optical disk device are different, and also to provide a recording and reproducing device, a recording condition setting program and a recording medium. <P>SOLUTION: A recording pulse condition recorded on the optical disk beforehand for specifying the pulse rising position and pulse falling position of a plurality of pulse strings for forming the recording mark by the time unit is read (S1), the read recording pulse condition is converted to the time unit of the optical disk device (S2), and the recording pulse condition is set to the optical disk device on the basis of the converted value (S3). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a recording / reproducing apparatus that performs optical modulation recording based on a recording condition corresponding to recording information and reproduces the recorded information, and more specifically, a recording condition provided for the recording / reproducing apparatus. And a recording condition setting program and a recording medium.

  In a recording / reproducing apparatus such as an optical disc apparatus that records a large amount of data, a pulse train that changes in accordance with recorded information is converted into a pulse train that is finer than a minimum unit of information, and a laser beam is intensity-modulated by the fine pulse train, Recording is performed by condensing the intensity-modulated laser beam on a recording medium and heating the recording medium to change the physical characteristics of the medium to form a recording mark. Here, standard recording conditions are recorded in advance on the optical disc as recording condition setting information for performing recording compensation such as the pulse width of the pulse train necessary for recording and the power of each laser beam corresponding to the pulse amplitude.

  Recording conditions include a recording pulse condition for specifying the rising position and the falling position of each pulse constituting the pulse train in units of time, and a recording power for identifying the laser beam power at the amplitude level of each pulse constituting the pulse train. There are conditions.

Conventionally, the time unit for setting the recording pulse width recorded on the optical disc and the set time unit in the optical disc apparatus are both designed to be the same as N [ns]. Note that the design itself in which the time unit for setting the recording pulse width recorded on the optical disc is the same as the set time unit in the optical disc apparatus is a well-known general matter (see, for example, Patent Document 1). ).
Japanese Patent Laid-Open No. 2000-200408 (published July 18, 2000)

  However, as the density increases further in the future, the influence of the pulse rise time and fall time will increase, and the setting of the recording pulse width will become strict, making it difficult to develop a laser driver. Therefore, on the optical disc apparatus side, instead of roughening the time resolution of the condition for setting the recording pulse width (recording pulse condition), a measure to compensate by the resolution of the condition in the power direction of the recording pulse (recording power condition) is considered. It is done. In some cases, the time unit of the recording pulse condition recorded in advance on the optical disc does not necessarily match the set time unit on the optical disc apparatus side. This is the case, for example, where one is in the ns order and the other is determined by the clock division ratio.

  The present invention has been made in view of the above-described conventional problems, and its purpose is that the time unit for setting the recording pulse width recorded on the optical disc and the set time unit in the optical disc apparatus are different. Another object of the present invention is to provide a writable recording condition setting method and setting apparatus, a recording / reproducing apparatus, a recording condition setting program, and a recording medium capable of forming a good recording mark.

  In order to solve the above problems, the recording condition setting method of the present invention specifies, in time units, pulse rising positions and pulse falling positions of a plurality of pulse trains that are recorded in advance on a recording medium to form recording marks. A recording condition setting method for reading a recording pulse condition to be read and setting the read recording pulse condition in a recording / reproducing apparatus, wherein the recording pulse condition is converted into a set time unit in the recording / reproducing apparatus, and the converted value is Based on this, the recording pulse condition is set in the recording / reproducing apparatus.

  In order to solve the above problems, the recording condition setting apparatus of the present invention specifies the pulse rising position and pulse falling position of a plurality of pulse trains recorded in advance on a recording medium in order to form a recording mark in units of time. A recording condition setting device for reading a recording pulse condition to be read and setting the read recording pulse condition in a recording / reproducing device, wherein the recording condition reading unit reads the recording pulse condition from the recording medium, and the recording condition reading unit reads the recording pulse condition. Recording condition conversion means for converting the issued recording pulse condition into a time unit that can be set by the recording / reproducing apparatus, and recording for setting the recording pulse condition in the recording / reproducing apparatus based on the converted value obtained by the recording condition converting means And a condition setting means.

  As described above, the recording pulse condition read by the recording medium (by the recording condition reading means) is converted into the time unit of the recording / reproducing apparatus (by the recording condition conversion means), and based on the converted value (the recording condition setting) Means) by setting the recording pulse condition in the recording / reproducing apparatus, even if the time unit for setting the recording pulse width recorded on the recording medium is different from the time unit on the recording / reproducing apparatus side. The pulse condition can be set in the recording / reproducing apparatus, and a good recording mark can be formed even in a recording / reproducing apparatus having a time unit different from that of the recording medium.

  In addition to the above configuration, the recording condition setting device of the present invention further includes a conversion value obtained by the recording condition conversion unit, and a predetermined value corresponding to a time unit of the recording / reproducing device. And the recording pulse condition is set in the recording / reproducing apparatus based on the comparison result.

  If the time unit for setting the recording pulse width recorded on the recording medium is different from the time unit on the recording / reproducing apparatus side, the converted value may include a fraction. In this case, the reproduction signal quality depends on the fractional processing.

As in the above configuration, the value of the recording / reproducing apparatus closer to the recording / reproducing apparatus is rounded up or rounded down with the predetermined value corresponding to the time unit of the recording / reproducing apparatus as a threshold value. By setting to, the fraction of the converted value can be processed appropriately, and even if the setting is based on the converted value, the reproduction signal quality is almost the same as when the time unit of the recording medium is equal to the device time unit. The recording condition setting apparatus of the present invention that can be obtained may be characterized in that, in addition to the above configuration, the predetermined value is a value that is half of a time unit in the recording / reproducing apparatus.

  As in the above configuration, the fraction processing can be performed with high accuracy by processing the fraction of the converted value using the half value of the time unit of the recording / reproducing apparatus as a threshold value.

  In addition to the above-described configuration, the recording condition setting method of the present invention further rounds up or rounds down the fraction of the converted value by comparison with a predetermined value according to the time unit of the recording / reproducing apparatus. When the fraction of the converted value of the condition indicating the pulse rising position is the same as the predetermined value, the fraction is rounded down and set to a value in the time direction of the time unit of the recording / reproducing apparatus. it can.

  In the recording condition setting device according to the present invention, in addition to the above-described configuration, the recording condition setting unit further includes the same value as the fraction of the converted value of the condition indicating the pulse rising position in the recording pulse condition. In this case, the fraction may be rounded down and set to a value in the time direction of the time unit of the recording / reproducing apparatus.

  If the above-mentioned predetermined value, which is a threshold value when processing fractions, is the same as the fraction, the criterion of which of the two values sandwiching the fraction is closer is ambiguous. It has been confirmed that better playback signal quality can be obtained by setting the value in the time direction forward direction than setting it in the time direction value.

  Therefore, in the case of the condition indicating the pulse rising position as in the above configuration, the fraction processing is more appropriately performed by truncating the fraction and setting it to the device time unit in the forward direction. It is possible to obtain a better reproduction signal quality.

  The condition indicating the pulse rising position includes, for example, a condition for changing the front edge portion of the recording mark and a condition for changing the rear edge portion of the recording mark.

  In addition to the above-described configuration, the recording condition setting method of the present invention further rounds up or rounds down the fraction of the converted value by comparison with a predetermined value according to the time unit of the recording / reproducing apparatus. When the fraction of the converted value of the condition indicating the pulse falling position of the signal is the same as the predetermined value, the fraction is rounded up and set to a value in the time direction of the time unit of the recording / reproducing apparatus. You can also.

  In the recording condition setting device of the present invention, in addition to the above-described configuration, the recording condition setting unit further includes a fraction of the converted value of the condition indicating a pulse falling position in the recording pulse condition and the predetermined value. If they are the same, the fraction may be rounded up and set to a value in the backward direction of the time unit of the recording / reproducing apparatus.

  If the above-mentioned predetermined value, which is the threshold value when fractions are processed, is the same as the fraction, the criterion of which of the two values sandwiching the fraction is closer is ambiguous, but the condition indicates the pulse falling position. Has confirmed that a better reproduction signal quality can be obtained by setting the value in the backward direction than the value in the forward direction.

  Therefore, in the case of the condition indicating the pulse falling position as in the above configuration, the fraction processing is more appropriate by rounding up the fraction (set by the recording condition setting means) and setting it to the device time unit in the backward direction. And better reproduction signal quality can be obtained.

  As a condition indicating the pulse falling position, for example, there is a condition for changing the width in the direction perpendicular to the circumferential direction of the track of the recording mark.

  In addition to the above-described configuration, the recording condition setting method of the present invention further reads out, from the recording medium, recording power conditions for specifying irradiation power at the amplitude levels of a plurality of pulse trains for forming recording marks, together with the recording pulse conditions. When the fraction is set to a value in the time forward direction or a value in the time backward direction of the recording / reproducing apparatus, the recording power condition related to the recording pulse condition is made lower than the value read from the recording medium. The recording / reproducing apparatus may be set.

  In addition to the above-described configuration, the recording condition setting device of the present invention further includes a recording power condition in which the recording condition reading unit specifies the irradiation power at the amplitude levels of a plurality of pulse trains for forming a recording mark. On the other hand, when the recording condition setting means sets the fraction to a value in the time front direction or a value in the time backward direction of the recording / reproducing apparatus, the recording power condition related to the recording pulse condition is: It can also be characterized in that the value is set to the recording / reproducing apparatus by lowering the value read from the recording medium.

  A condition indicating a pulse rising position or a condition indicating a pulse falling position, where the fraction is the same as the predetermined value, and the fraction is processed in a direction in which the reproduction signal quality is good, and the pulse rising position and the pulse falling position are processed. The direction in which the recording medium is moved is a direction in which the light energy applied to the recording medium is increased.

  Therefore, as described above, by reducing the recording power condition of the pulse whose rising position and falling position are moved (by the recording power condition setting means) below the standard, the energy irradiated onto the recording medium can be reduced. The increase can be reduced and a better recording mark can be formed.

  In addition to the above configuration, the recording condition setting apparatus of the present invention further sets test conditions by performing test writing on a recording medium using the recording pulse conditions and / or recording power conditions set in the recording / reproducing apparatus. A test writing means may be further provided.

  As described above, recording is performed after the trial writing operation is performed (by the trial writing means) using the recording pulse condition and / or the recording power condition set in the time unit of the recording / reproducing apparatus based on the converted value. By setting conditions, it is possible to set recording conditions with higher accuracy.

  The recording / reproducing apparatus of the present invention is characterized by including the above-described recording condition setting apparatus of the present invention in order to solve the above-described problems.

  This makes it possible to set the recording pulse condition in the recording / reproducing apparatus even if the time unit for setting the recording pulse width recorded on the recording medium is different from the time unit on the recording / reproducing apparatus side. In addition, it is possible to provide a recording / reproducing apparatus capable of forming a good recording mark even on recording media having different time units.

  The recording condition setting device may be realized by a computer. In this case, a recording condition setting program for causing the computer to operate the recording condition setting device by causing the computer to operate as the respective means, and its A computer-readable recording medium that records the recording condition setting program also falls within the scope of the present invention.

  Even with the recording condition setting method of the present invention or the recording condition setting apparatus of the present invention, even if the time unit for setting the recording pulse width recorded on the recording medium is different from the time unit on the recording / reproducing apparatus side The recording pulse condition can be set in the recording / reproducing apparatus, and a good recording mark can be formed even in a recording / reproducing apparatus having a time unit different from that of the recording medium.

  An embodiment of the present invention will be described below with reference to FIGS.

  As shown in FIG. 2, the optical disk apparatus 1 according to the present embodiment includes an optical disk 10, an optical head 11, a pickup 12, a pickup driving circuit 13, a laser driving circuit 14, a reproducing circuit 15, a sensor 30, And a control unit 20. The optical head 11 is mounted on the pickup 12.

  In the optical disc apparatus 1, during recording, the control unit 20 moves the pickup 12 to a track (not shown) of the rotating optical disc (recording medium) 10 via the pickup drive circuit 13. Then, the control unit 20 sets recording conditions via the laser driving circuit 14 and irradiates the recording part of the optical disc 10 with a recording laser beam from the optical head 11. As a result, information is recorded on the track of the optical disc 10.

  At the time of reproduction, the control unit 20 moves the pickup 12 to the recording part of the optical disc 10 via the pickup drive circuit 13. Then, the control unit 20 irradiates the optical disk 10 with a reproduction laser beam from the optical head 11 via the laser drive circuit 14. The reflected light from the optical disk 10 is detected by the optical head 11, and the detected reflected light is converted into a reproduction signal by the reproduction circuit 15 and then input to the control unit 20. Thereby, the information recorded on the track of the optical disc 10 is reproduced.

  The sensor 30 is for detecting that the optical disc 10 is loaded in the optical disc apparatus 1 and / or for detecting a change in the recording environment on the optical disc 10. The sensor 30 includes, for example, a temperature sensor for detecting the temperature of the recording part of the optical disc 10. Then, the sensor 30 outputs the detected result to the control unit 20 as a detection signal.

  In addition to the functions described above, the control unit 20 also has a function of appropriately starting the recording condition setting operation. In addition to when the optical disk 10 is loaded in the optical disk apparatus 1, the control unit 20 detects when a predetermined change is detected in the recording environment from the detection signal of the sensor 30 during the information recording operation, or the previous test writing. When a predetermined time elapses, the recording condition setting operation is started as appropriate. That is, the control unit 20 is a recording condition setting device, which is a recording condition reading unit, a recording condition conversion unit, a recording condition setting unit, a recording condition setting unit, and a test writing unit.

  In the optical disc apparatus 1, as shown in FIG. 3, recording conditions are set based on trial writing to the setting area 41 of the optical disc 10. Information is recorded on each track according to the recording condition. Note that the recording operation to the user area 42 after setting the recording conditions of the optical disc apparatus 1 is the same as a generally known operation. Further, it is assumed that standard recording conditions including a standard recording pulse condition and a standard recording power condition described later are recorded in the setting area 41 in advance.

  In the optical disc apparatus 1, the standard recording conditions in the setting area 41 of the optical disc 10 are read, and the standard recording conditions are used for setting the recording conditions. Further, the read standard recording conditions may be stored in a memory (not shown) which is a storage means provided in the control unit 20, and read and used. Note that the position of the setting area 41 is not limited to the position shown in FIG. 3, and may exist at an arbitrary radial position of the optical disc 10, or a plurality of setting areas 41 may exist.

  Next, a recording condition setting method implemented in the optical disc apparatus 1 will be described with reference to FIGS.

  Hereinafter, (1, 7) RLL (Run Length Limited code) will be described as an example of a modulation method. However, in the present invention, the modulation scheme is not limited to the (1,7) RLL modulation scheme, and other modulation schemes may be used.

  The (1,7) RLL code is a code in which the minimum value and the maximum value of the inversion interval are limited in magnetic and optical digital recording. Further, in this (1, 7) RLL modulation system, a pulse train of recording pulses for forming one recording mark is composed of a start end and an end in the shortest recording mark. Is done. A recording mark longer than the shortest recording mark is constituted by adding an intermediate portion corresponding to the mark length between the start end portion and the end portion.

  In other modulation systems, there is a method in which the shortest recording mark length starts from 3T. At this time, the shortest recording mark length is constituted by the start end portion, the intermediate portion, and the end portion (for example, DVD-RW). Further, even if the shortest mark length is 2T, there are cases where the shortest mark length is composed only of the start end (for example, DVD-R).

  FIG. 4 shows recording information, a pulse train corresponding to this, and the shape of the recording mark to be formed. A pulse train of recording pulses corresponding to the recording information is set in consideration of a medium temperature distribution for recording on the optical disc 10. FIG. 4 shows a pulse train for dealing with 4T marks. As described above, the pulse train is configured by combining the start and end portions, and the intermediate portion located at 3T marks or more. Here, “T” represents the time for one clock cycle. Therefore, for example, a 4T mark is a mark in which “1” is recorded in a time corresponding to four clock cycles, that is, a recording area.

  Further, as shown in the figure, the pulse train is composed of recording power, erasing power, and bias power amplitude levels, which are referred to as recording power conditions. In the figure, the recording power of the pulses at the start end and the intermediate portion is the same, but this is not necessarily the case, and the recording power may be different for each pulse (start end, each intermediate portion).

  Next, FIG. 5 shows a pulse train for forming each of the 2T mark to the 8T mark, and recording pulse conditions for realizing the pulse train. The recording pulse condition specifies a pulse rising position and a pulse falling position of a plurality of pulse trains for forming a recording mark in a time unit. The start pulse position dTtop, the start pulse width Ttop, and the end portion of the pulse train It consists of a pulse end position dTend and an intermediate part pulse width Tmp. The start end pulse start position dTtop is the start start pulse start condition (condition for changing the front edge of the recording mark), the start end pulse width Ttop is the start end pulse width, and the end pulse end position dTend is the end pulse. The end position (condition for changing the trailing edge part of the recording mark) and the intermediate part pulse width Tmp indicate the pulse width of the intermediate part. By changing these values, the shape of the recording mark to be formed changes. The standard values of the recording conditions including the recording pulse condition and the recording power condition are recorded in advance in the setting area 41 of the optical disc 10 as the standard recording conditions.

  These recording pulse conditions are set according to the mark length, and the settings are independent of each other. That is, the pulse train of the shortest recording mark length is composed of a start end and a termination end, and the recording pulse conditions are the start end pulse start position dTtop, the start end pulse width Ttop, and the end end pulse end position dTend. The conditions are not used for setting the start and end portions of other mark lengths. For example, the start end pulse start position dTtop, the start end pulse width Ttop, and the end end pulse end of the recording pulse conditions of the 3T mark The position dTend is completely different from this, and is set individually.

  Here, the relationship between the recording pulse condition and the recording mark will be described. First, regarding the start end pulse start position dTtop, the start end position of the recording mark moves forward when this becomes larger, and the start end position of the recording mark moves rearward when it becomes smaller. In addition, when the start end pulse width Ttop increases, the width of the head portion of the recording mark (dimension in the direction perpendicular to the circumferential direction of the track) increases. Conversely, when the pulse width Ttop decreases, the width of the head portion of the recording mark decreases. At the end pulse end position dTend, when it increases, the end position of the recording mark moves backward, and conversely, when it decreases, the end position of the recording mark moves forward. In the intermediate portion pulse width Tmp, the width of the recording mark increases as it increases, and conversely as it decreases, the width decreases.

  The start end pulse start position dTtop and the end part pulse end position dTend are conditions indicating the pulse rising positions of the start end part and the end part, respectively. The start end part pulse width Ttop and the intermediate part pulse width Tmp are respectively These are the conditions indicating the pulse falling positions of the start and middle portions.

  Here, the following description will be given by taking as an example the case where the optical disc apparatus 1 having a time resolution of 2 ns is used for the optical disc 10 in which the recording pulse condition is recorded in 1 ns. At this time, the setting deviation between the recording pulse condition recorded on the optical disc 10 and the recording pulse condition set by the apparatus is ± 1 ns at the maximum. Therefore, an apparatus that can set the recording pulse condition every 1 ns was used, and the influence of the setting deviation was measured.

  On the optical disc 10, recording pulse conditions are recorded for each recording mark length for each of 2T mark, 3T mark, 4T mark or more (up to 8T mark). As a pattern to be recorded, a test pattern including 2T mark to 8T mark was used to reproduce the recorded pattern and measure the jitter value. Jitter refers to disturbances such as amplitude, pulse width, pulse position, repetition frequency, and pulse interval in a pulse train.

  First, a change in jitter was investigated when the start end pulse start position dTtop in the 2T mark recording pulse conditions was changed. At this time, of the 2T mark recording pulse conditions, conditions other than the start end pulse start position dTtop and the start end pulse width Ttop, and recording pulse conditions of 3T mark or more are fixed. In this case, the falling position of the start end pulse is fixed, and the value of the start end pulse width Ttop changes by changing the start end pulse start position dTtop.

  The result is shown in FIG. Comparing the case where the start end pulse start position dTtop is shifted by +1 ns in the forward direction and the case where it is shifted by −1 ns, the amount of deterioration of jitter is smaller in +1 ns, which is closer to the jitter value in the standard (± 0 ns). From this, it can be said that if the start end pulse start position dTtop is shifted in the forward direction, a good recording mark can be formed, and a good reproduction signal quality can be obtained.

  Next, a change in jitter when the start end pulse width Ttop in the 2T mark recording pulse conditions was changed was examined. At this time, conditions other than the start end pulse width Ttop among the recording pulse conditions of the 2T mark and recording pulse conditions of the 3T mark or more are fixed.

  FIG. 7 shows the result. Comparing the case where the start end pulse width Ttop is shifted by +1 ns in the backward direction and the case where it is shifted by −1 ns, the deterioration amount of jitter is smaller in +1 ns, which is close to the jitter value in the standard (± 0 ns). From this, it can be said that when the start end pulse width Ttop is shifted backward in time, a good recording mark can be formed, and good reproduction signal quality can be obtained.

  Subsequently, a change in jitter was examined when both the start end pulse start position dTtop and the start end pulse width Ttop falling position in the 2T mark recording pulse conditions were changed. At this time, conditions other than the start end pulse start position dTtop and the start end pulse width Ttop among the recording pulse conditions for the 2T mark and the recording pulse conditions for the 3T mark or more are fixed.

  FIG. 8 shows the result. In FIG. 8, the start end pulse start position dTtop is changed by +1 ns in the forward direction and the falling position of the start end pulse width Ttop is changed by +1 ns in the backward direction (that is, the start end pulse width Ttop is +2 ns). This is expressed as +1 ns on the horizontal axis of the graph. Conversely, the start end pulse start position dTtop is changed by −1 ns with respect to the forward direction, and the falling position of the start end pulse width Ttop is changed by −1 ns with respect to the backward direction. (That is, the start end pulse width Ttop is −2 ns) is represented as −1 ns on the horizontal axis of the graph.

  When both are compared, the amount of jitter deterioration is smaller in +1 ns, and is closer to the jitter value in the standard (± 0 ns). From this, it can be said that when the start end pulse width Ttop is shifted backward in time, a good recording mark can be formed, and good reproduction signal quality can be obtained. As a result, it was confirmed that even when the conditions under which good reproduction signal quality was obtained in each of FIGS. 6 and 7 were combined, good reproduction signal quality could be obtained.

  Next, the change in jitter when the end pulse end position dTend in the 2T mark recording pulse condition was changed was examined. At this time, conditions other than the end pulse end position dTend among the recording pulse conditions of the 2T mark and the recording pulse conditions of the 3T mark or more are fixed.

  FIG. 9 shows the result. Comparing the case where the end pulse end position dTend is shifted by +1 ns in the forward direction and the case where it is shifted by −1 ns, there is almost no difference between the two. From this, it can be said that there is no particular advantage between +1 ns and −1 ns in the change of the terminal end pulse end position dTend alone.

  Therefore, as a combination in which good reproduction signal quality is obtained in the result of FIG. 8, the start end pulse start position dTtop is changed by +1 ns in the forward direction, and the falling position of the start end pulse width Ttop is changed by +1 ns in the backward direction. Then, the change in jitter was examined when the end pulse end position dTend was changed. At this time, the recording pulse condition of 3T mark or more is fixed.

  FIG. 10 shows the result. Comparing the case where the end pulse end position dTend is shifted by +1 ns in the forward direction and the case where it is shifted by −1 ns, the deterioration amount of jitter is smaller in +1 ns. For this reason, if the end pulse end position dTend is shifted in the forward direction, when considering a combination with other recording pulse conditions, a good recording mark can be formed and a good reproduction signal quality can be obtained. I can say that.

  Summarizing the results of FIGS. 6 to 10 described above, the following can be said.

  1. Of the recording pulse conditions, the condition indicating the pulse rising position, that is, the start-end pulse start position dTtop and the end-part pulse end position dTend are changed in the forward direction rather than in the backward direction. In this case, a good recording mark can be formed, and a good reproduction signal quality can be obtained.

  2. Of the recording pulse conditions, the condition indicating the pulse falling position, that is, the end position of the start end pulse width Ttop is better when it is changed in the backward direction than in the forward direction. Recording marks can be formed, and good reproduction signal quality can be obtained.

  Since the above is the result for the recording pulse condition for the 2T mark, the same applies to the recording pulse condition for the 3T mark, the recording pulse condition for the 4T mark or more, and the recording pulse condition for all of the 2T to 8T marks. It was decided to investigate whether or not.

  In FIG. 11, when the start end pulse start position dTtop of the 3T mark is changed by +1 ns in the forward direction, the falling position of the start end pulse width Ttop of the 3T mark is changed by +1 ns in the backward direction, and further, A change in jitter is shown when the falling position of the intermediate part pulse width Tmp is changed by +1 ns in the backward direction and then the end pulse end position dTend of the 3T mark is changed. At this time, the recording pulse conditions for the 2T mark and the 4T mark or more are fixed.

  Comparing the case where the end pulse end position dTend is shifted by +1 ns in the forward direction and the case where it is shifted by −1 ns, the amount of deterioration of jitter becomes smaller in +1 ns. From this, it can be said that the same tendency as the 2T mark recording pulse condition was obtained under the 3T mark recording pulse condition.

  In FIG. 12, the start end pulse start position dTtop of a mark of 4T or more (marks from 4T to 8T) is changed by +1 ns in the forward direction, while the falling position of the start end pulse width Ttop of the mark of 4T or more is changed after time. In the direction, the falling position of the intermediate pulse width Tmp of the mark of 4T or more is changed by + 1ns in the backward direction, and then the end pulse end position dTend of the mark of 4T or more is changed. Shows the change in jitter. At this time, the recording pulse conditions of the 2T mark and the 3T mark are fixed.

  Comparing the case where the end pulse end position dTend is shifted by +1 ns in the forward direction and the case where it is shifted by −1 ns, the deterioration amount of jitter is smaller in +1 ns. From this, it can be said that the result of the same tendency as the recording pulse condition of the 2T mark and the 3T mark was obtained even under the recording pulse condition of the mark of 4T or more.

  In FIG. 13, the start end pulse start position dTtop of all marks (marks from 2T to 8T) is changed by +1 ns in the forward direction, while the falling position of the start end pulse width Ttop of all the marks is moved backward in the time. Jitter when changing the falling position of the intermediate part pulse width Tmp of all marks by +1 ns in the backward direction and changing the terminal end pulse end position dTend of all marks Shows changes.

  Comparing the case where the end pulse end position dTend is shifted by +1 ns in the forward direction and the case where it is shifted by −1 ns, the amount of jitter deterioration is smaller in +1 ns. From this, it can be said that the result of the same tendency was obtained even when the recording pulse conditions of all marks, that is, when 2T mark, 3T mark, 4T or more marks were combined.

  Next, a specific operation of recording condition setting in the optical disc apparatus 1 will be described with reference to the flowcharts of FIGS.

  The overall operation of recording condition setting is shown in the flowchart of FIG. In the optical disc apparatus 1, the recording pulse condition recorded on the optical disc 10 is first read under the control of the control unit 20 (S1). Next, the read recording pulse condition is converted into a time unit of the optical disc device 1 (hereinafter, device time unit) (S2). Then, based on the value obtained by conversion in S2, a recording pulse condition is set in the optical disc apparatus 1 (S3).

  The details of the process for setting the recording pulse condition in the optical disc apparatus 1 based on the converted value in S3 are shown in the flowchart of FIG. As described above, when the optical disc apparatus 1 having a time resolution of 2 ns is used for the optical disc 10 in which the recording pulse condition is recorded in units of 1 ns, the recording pulse conditions read in S1 are Some include odd [ns]. Such an odd number [ns] condition, when converted into a device time unit in S2, has a time resolution of 2 ns, so that the odd number [ns] has a fraction X of 0.5. In S3, the fraction X of 0.5 is rounded down to “0” or rounded up to “1” to obtain an integer value, and the recording pulse condition is set based on this.

  First, the control unit 20 determines whether or not there is a fraction X in the converted value calculated in S2 (S31). Here, if there is no fraction X, the process proceeds to S35, and the recording pulse condition is set based on the converted value as it is.

  On the other hand, if there is a fraction X in the converted value, it is determined whether the fraction X is greater than, smaller than, or equal to a predetermined value Y (here, 0.5) (S32). When the fraction X is smaller than 0.5, the fraction X is rounded down (S34). On the other hand, when the fraction X is larger than 0.5, the fraction X is rounded up (S36), and the fraction X is rounded down (an integer). A recording pulse condition is set based on a numerical value) or a rounded up value (integer value). For example, if the fraction X is 0.1, the fraction is rounded down, and if the fraction X is 0.9, it is rounded up.

  As described above, when the converted value has a fraction X and the fraction X is close to the value of the apparatus time unit, the fraction X is rounded down or rounded up and set to a value close to the apparatus time unit. It is possible to obtain a reproduction signal quality substantially equivalent to the case where the time unit is equal to the apparatus time unit.

  On the other hand, when the fraction X is equal to 0.5, it is determined whether the recording pulse condition indicates a pulse rising position or a pulse falling position. If the former, that is, dTend at the start end pulse start position dTtop or the end part pulse end position, the fraction is rounded down to a value in the unit time unit in the forward direction (S34). A recording pulse condition is set based on a value obtained by discarding X. On the other hand, in the case of the latter, that is, the start end pulse width Ttop or the intermediate part pulse width Tmp, the fraction is rounded up so as to be the value of the device time unit in the backward direction (S36), and in S35, the fraction X is rounded up. The recording pulse condition is set based on the measured value.

  If the conversion value has a fraction X, and the fraction X is between 0.5 and far from either side of the device time unit value, the criterion that it is close to the device time unit becomes ambiguous. However, by moving up and down in the direction in which a good reproduction signal quality is obtained in this way, it is possible to obtain a reproduction signal quality substantially equivalent to the case where the time unit of the optical disc 10 is equal to the apparatus time unit. .

  Here, the predetermined value Y is set to “0.5” between “0” and “1”. However, when the fraction X becomes close to 0.5, it becomes difficult to draw up and down. In addition, variations in the apparatus time unit itself due to errors in the optical disc apparatus 1 and variations in the set values can be considered. For this reason, the predetermined value Y that is the threshold for carry-up and carry-down is not strictly set to a value that is half the apparatus time unit, but may be set to a value such as 0.6 or 0.4.

  Further, in the optical disc apparatus 1 of the present embodiment, although not shown in the flowcharts of FIGS. 1 and 14, the fraction X becomes the same as the predetermined value Y, and the fraction X is rounded up or down to increase the pulse rising position or When the falling position of the pulse is moved, the pulse recording power condition is set lower than the standard read from the optical disk 10 in S3. That is, when the fraction X and the predetermined value Y are the same, the direction in which the pulse rising position and the pulse falling position are moved is the direction in which the energy irradiated onto the optical disc 10 is increased, and the energy increases. Think about the impact. Thereby, an increase in energy irradiated onto the optical disk 10 can be reduced, and a better recording mark can be formed.

  Specifically, it is a condition indicating a pulse rising position among the recording pulse conditions, that is, when the start end pulse start position dTtop is moved, the recording power of the pulse at the start end is set to the end pulse end position dTend. For the above, the recording power of the pulse immediately before the terminal portion may be reduced. The pulse immediately before the end portion is the pulse at the start end if it is a 2T mark, and the pulse at the immediately preceding intermediate portion if the mark is 3T or more.

  Further, for the end position of the start end pulse width Ttop, which is a condition indicating the pulse falling position, the recording power of the pulse at the start end section is used. For the end position of the intermediate section pulse width Tmp, the recording power of the intermediate section pulse is set. It only has to be lowered.

  As described above, in the optical disc apparatus 1 according to the present embodiment, the recording pulse condition recorded in advance on the optical disc 10 is read under the control of the control unit 20, and the read recording pulse condition is changed to the optical disc apparatus. Since the recording pulse condition is set in the optical disc apparatus 1 based on the converted value, the time unit for setting the recording pulse width recorded on the optical disc 10, Even when the set time unit (apparatus time unit) is different, the recording pulse condition can be set in the optical disc apparatus 1, and a good recording mark can be formed even in the optical disc apparatus 1 in which the time unit is different from the optical disc 10. can do.

  The fraction X of the value obtained by converting the recording pulse condition recorded on the optical disc 10 into the unit of device time that can be set by the optical disc apparatus 1 is closer to the unit when the fraction X is close to the unit of apparatus. When the fraction X is a value in a range in which the criterion that it is close to the device unit is ambiguous, such as the vicinity of 0.5 as described above, a good reproduction signal quality is obtained. Round down or round up. Therefore, even if the setting is based on the conversion, it is possible to obtain a reproduction signal quality substantially equivalent to the case where the time unit of the optical disc 10 is equal to the apparatus time unit.

  In the above, when the fraction X and the predetermined value Y are the same, and the pulse rising position and the pulse falling position are moved, the recording power condition of the pulse whose rising position and falling position are moved from the standard. Therefore, an increase in energy irradiated onto the optical disk 10 can be reduced and a better recording mark can be formed.

  Further, a trial writing operation may be performed using the recording pulse conditions set in the processes of S1 to S3, and then the recording conditions may be finally set. By performing the trial writing operation, it is possible to set a recording condition with higher accuracy. The test writing operation is a generally well-known operation, and specifically, an operation for recording on a disc using a plurality of recording conditions and setting an optimum recording condition based on the reproduction signal. Here, as a change in a plurality of recording conditions, the recording power condition may be changed, or the recording pulse condition may be changed. Moreover, you may change both.

  The flowchart of FIG. 15 shows the recording condition setting operation when the test writing operation is performed. In S3 of FIG. 1, after setting a recording pulse condition (recording pulse condition and / or recording power condition) in units of apparatus time, a test writing operation is performed using the recording pulse condition (S11). The recording condition obtained as a result of the trial writing operation in S11 is set as the optimum recording condition (S12).

  In addition, this Embodiment does not limit the scope of the present invention, and various modifications can be made within the scope of the present invention. For example, it is desirable to set the recording condition by trial writing at least once for each track, but it is not always necessary to set it for all the tracks, and may be set for a plurality of tracks.

  In addition, although the present embodiment has been described using the recording pulse condition for the mark length, it should be used similarly when the recording pulse condition is set for the combination of the mark length and the space length. Can do.

  Further, as an example in which the time unit for setting the recording pulse condition is different between the optical disc 10 and the optical disc device 1, the time unit of the optical disc 10 is 1 [ns] and the time unit of the optical disc device 1 is 2 [ns]. However, for example, when one is in the ns order and the other is determined by the frequency division ratio of the clock, various considerations are possible, and the present invention is not limited to the ns order.

  The optical disc apparatus 1 includes a CPU (Central Processing Unit) that is a calculation means for executing instructions of a program (recording condition setting program) that realizes each function of the control unit 20, and a ROM that is a storage means for storing the program. (Lead Only Memory), a RAM (Random Access Memory) that is a storage means for expanding the program, a storage device (storage medium) (not shown) such as a memory that is a storage means for storing the program and various data, and the like .

  An object of the present invention is to provide a recording medium in which a program code (execution format program, intermediate code program, source program) of a control program, which is software for realizing the functions described above, can be read by a computer, the optical disc apparatus 1. This can also be achieved by reading the program code recorded in the recording medium and executing it by the computer (or CPU or MPU). In this case, since the program code itself read from the recording medium realizes the above-described function, the recording medium on which the program code is recorded constitutes the present invention.

  The control program of the present embodiment is a control program for operating the above-described optical disc apparatus 1, and causes a computer to function as each of the means described above.

  Therefore, it is possible to provide a control program that causes a computer to function as each of the above-described means.

  Further, the computer-readable recording medium of the present embodiment is a recording medium of the control program described above.

  Therefore, it is possible to provide a computer-readable recording medium in which the control program is recorded.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the technical means disclosed in different embodiments can be appropriately combined. Embodiments to be described are also included in the technical means of the present invention.

  The present invention can be applied to a recording / reproducing apparatus that handles a recordable optical disc such as a DVD-RW or a DVD-R.

1 is a flowchart of a recording condition setting process performed in an optical disc apparatus according to an embodiment of the present invention. It is a block diagram which shows the structure of the said optical disk apparatus. It is a perspective view which shows the optical disk in which information is recorded by the said optical disk apparatus. It is a timing chart explaining the setting of the pulse train corresponding to recording information. It is a timing chart explaining various recording pulse parameters constituting a pulse train and recording pulse conditions for forming an 8T mark from a 2T mark. It is explanatory drawing which shows the influence with respect to recording / reproducing performance of a recording pulse condition change. It is explanatory drawing which shows the influence with respect to recording / reproducing performance of a recording pulse condition change. It is explanatory drawing which shows the influence with respect to recording / reproducing performance of a recording pulse condition change. It is explanatory drawing which shows the influence with respect to recording / reproducing performance of a recording pulse condition change. It is explanatory drawing which shows the influence with respect to recording / reproducing performance of a recording pulse condition change. It is explanatory drawing which shows the influence with respect to recording / reproducing performance of a recording pulse condition change. It is explanatory drawing which shows the influence with respect to recording / reproducing performance of a recording pulse condition change. It is explanatory drawing which shows the influence with respect to recording / reproducing performance of a recording pulse condition change. It is a flowchart of an example of the recording condition setting process in the flowchart of FIG. FIG. 2 is a flowchart when a test writing process is performed after a recording condition setting process in the flowchart of FIG. 1.

Explanation of symbols

1 Optical disk device (recording / reproducing device)
10 Optical disc (recording medium)
12 pickup 16 recording / reproducing circuit group 20 control unit (recording condition setting device, recording condition conversion means, recording condition setting means, recording condition reading means, test writing means)
30 Sensor 41 Setting area

Claims (17)

A recording pulse condition that specifies the pulse rising position and pulse falling position of a plurality of pulse trains for forming a recording mark recorded in advance on a recording medium in units of time is read, and the read recording pulse condition is recorded and reproduced. Recording condition setting method to be set to
A recording condition setting method, wherein the recording pulse condition is converted into a time unit set in the recording / reproducing apparatus, and the recording pulse condition is set in the recording / reproducing apparatus based on the converted value.   While the fraction of the converted value is rounded up or rounded down by comparison with a predetermined value corresponding to the time unit of the recording / reproducing apparatus, the fraction of the converted value in the condition indicating the pulse rising position among the recording pulse conditions is the predetermined value. 2. The recording condition setting method according to claim 1, wherein the fraction is rounded down and set to a value in a time-forward direction in a time unit of the recording / reproducing apparatus.   While the fraction of the converted value is rounded up or rounded down by comparison with a predetermined value corresponding to the time unit of the recording / reproducing device, the fraction of the converted value of the condition indicating the pulse falling position among the recording pulse conditions is the predetermined value. 2. The recording condition setting method according to claim 1, wherein when the value is the same as the value, the fraction is rounded up and set to a value in the backward direction of the time unit of the recording / reproducing apparatus. Along with the recording pulse condition, the recording power condition for specifying the irradiation power at the amplitude level of a plurality of pulse trains for forming a recording mark is also read from the recording medium,
When the fraction is set to a value in the time direction of the time unit of the recording / reproducing apparatus or a value in the time direction, the recording power condition related to the recording pulse condition is set lower than the value read from the recording medium. 4. The recording condition setting method according to claim 2, wherein the recording condition is set in a reproducing apparatus. A recording pulse condition that specifies the pulse rising position and pulse falling position of a plurality of pulse trains for forming a recording mark recorded in advance on a recording medium in units of time is read, and the read recording pulse condition is recorded and reproduced. A recording condition setting device to be set to
A recording condition reading means for reading a recording pulse condition from the recording medium;
Recording condition conversion means for converting the recording pulse condition read by the recording condition reading means into a time unit that can be set by the recording / reproducing apparatus;
Recording condition setting means for setting a recording pulse condition in the recording / reproducing apparatus based on the converted value obtained by the recording condition converting means;
A recording condition setting device comprising:   The recording condition setting means compares the converted value obtained by the recording condition conversion means with a predetermined value corresponding to the time unit of the recording / reproducing apparatus, and sets the recording pulse condition to the recording / reproducing apparatus based on the comparison result. 6. The recording condition setting device according to claim 5, wherein the recording condition setting device is set.   7. The recording condition setting apparatus according to claim 6, wherein the predetermined value is a half value of a time unit in the recording / reproducing apparatus.   When the recording condition setting means has the same value as the fraction of the converted value indicating the pulse rising position in the recording pulse condition and the predetermined value, the fraction is rounded down to a time unit of time of the recording / reproducing apparatus. 7. The recording condition setting device according to claim 6, wherein the recording condition setting device is set to a forward value.   9. The recording condition setting apparatus according to claim 8, wherein the condition indicating the pulse rising position is a condition for changing a front edge portion of a recording mark.   9. The recording condition setting apparatus according to claim 8, wherein the condition indicating the pulse rising position is a condition for changing a trailing edge portion of the recording mark.   When the recording condition setting means has the same fractional value as the fractional value indicating the pulse falling position of the recording pulse condition and the predetermined value, the fractional value is rounded up to the time unit of the recording / reproducing apparatus. 7. The recording condition setting device according to claim 6, wherein the recording condition setting device is set to a value in the backward direction.   12. The recording condition setting apparatus according to claim 11, wherein the condition indicating the pulse falling position is a condition for changing a width of the recording mark in a direction perpendicular to the circumferential direction of the track. While the recording condition reading means reads from the recording medium the recording power condition for specifying the irradiation power at the amplitude level of a plurality of pulse trains for forming the recording mark,
When the recording condition setting means sets the fraction to a value in the time direction of the time unit of the recording / reproducing apparatus or a value in the time direction, the recording power condition related to the recording pulse condition is read from the recording medium. 12. The recording condition setting device according to claim 8 or 11, wherein the recording condition setting device is set to be lower than the set value.   14. A test writing means for setting a recording condition by performing a test writing on a recording medium using a recording pulse condition and / or a recording power condition set in the recording / reproducing apparatus. The recording condition setting device according to any one of the above.   15. A recording / reproducing apparatus comprising the recording condition setting apparatus according to any one of claims 5 to 14.   A recording condition setting program for operating the recording condition setting device according to any one of claims 5 to 14, wherein the recording condition setting program causes a computer to function as each of the above means.   A computer-readable recording medium on which the recording condition setting program according to claim 16 is recorded.

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