JP2008041192A - Device and method for optical disk recording - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for optical recording, capable of recording data with optimal recording power, according to the disk recording position. <P>SOLUTION: The device 100 for optical disk recording is provided with an interruption detection part for detecting an interruption position, where data recording in an optical disk 110 is interrupted, a data recording part for recording new data continuously from the data recorded in the optical disk 110, a reproduced signal detection part for detecting the reproduced signal quality at the interruption position, and a recording power deciding part for deciding the recording power for recording new data, according to the reproducing signal quality detected by the reproduced signal detection part. As the reproduced signal quality, asymmetry, β value, or jitter values can be used. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical disc recording apparatus and an optical disc recording method, and more particularly to an optical disc recording apparatus and an optical disc recording method capable of adjusting recording power.

  When recording on an optical disk, the optimum recording power, usually called OPC (Optimum Power Control), is selected. The optimum recording power is the optimum recording power when data is recorded on the disc. This optimum recording power is calculated based on the result of trial writing while changing the recording power in a dedicated area for performing OPC called PCA (Power Calibration Area) provided as standard on the optical disc.

  The optical disk recording device stores an address for recording and a recording power at the address when performing trial writing to the PCA. Then, after trial writing, the signal at the address where the data is stored is read out. At this time, reproduction signal quality, for example, signal level, asymmetry, β value and the like are measured, and the optimum recording power is determined based on the magnitude of these values.

  For example, as shown in FIG. 1, the PCA of a DVD-R disc is an innermost area 112 (addresses 1E800 to 203B0) of the disc. As a method for determining the recording power in the DVD-R disc, first, trial writing of data is performed while gradually increasing the recording power to the PCA 112. For example, the optical disk recording apparatus records power until recording at a recording power of 18 mW at the address 203B0, such as a recording power of 10 mW at the address 203A1 of the disk, a recording power of 10.5 mW at the address 203A2, and a recording power of 11 mW at the address 203A3. Record while raising.

  Next, the data recorded at the addresses 203A0 to 203B0 is reproduced, and the asymmetry of each address is measured. Asymmetry is one of the parameters that can be used to evaluate the recording state, indicating a positive value if the recording power is smaller than the appropriate power and a negative value if the recording power is larger. In a general disc, the optimum recording power is obtained when the asymmetry is 0%. Therefore, the recording power at which the asymmetry is 0% is estimated from the recording power when the data is recorded on the PCA 112. For example, as shown in FIG. 2B, when the asymmetry of address 2033A is 2% and the asymmetry of address 203AB is -2%, the recording power of address 203AA is 15.0 mW and the recording power of address 203AB Is 15.5 mW, the recording power at which the asymmetry is 0% is estimated to be 15.25 mW, as shown in FIG. From this result, the optical disk recording apparatus records on the disk with a recording power of 15.25 mW in actual data recording.

  In the DVD-R disc, a technique called R-OPC is also used in combination. R-OPC is to perform recording and change the recording power so that the reflected light level at that time becomes a constant value in order to follow the change in the optimum recording power due to a temperature change or the like. This is based on the characteristic of the DVD-R disc that the reflected light level at the time of recording in the optimum recording state is constant.

JP 2005-135481 A

  However, although PCA is defined at the innermost circumference of the disc, the actual recording sensitivity of the disc causes unevenness in the manufacture of the disc. For this reason, the optimum recording power differs depending on the recording position of the disc, and there is a problem that the optimum recording power obtained by OPC may not be appropriate depending on the recording position. Such variation in the optimum recording power depending on the recording position on the disc is caused by uneven sensitivity of the recording film, a difference in reflectance of the recording film, a skew when the disc is mounted on the optical disc recording apparatus, etc. The quality of the recorded data will be greatly deteriorated.

  In DVD-R, although the above problem is improved to some extent by R-OPC, if a difference in the reflectance of the recording film occurs, R-OPC may malfunction, and the recording quality may be deteriorated. Further, the R-OPC method is effective only for a write-once disc that performs recording by burning a dye, and more frequently used rewritable phase change discs (for example, DVD ± RW, CD). There is currently no effective R-OPC method for (-RW etc.).

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a new and improved recording capable of recording data with an optimum recording power in accordance with the recording position of the disc. An optical disc recording apparatus and a recording method are provided.

  In order to solve the above problems, according to an aspect of the present invention, an optical disc recording apparatus for recording data on an optical disc is provided. According to such an optical disc recording apparatus, an interruption detection unit that detects an interruption position at which data recording on the optical disc is interrupted, a data recording unit that records new data continuously to the data recorded on the optical disc, and an interruption A reproduction signal detection unit for detecting reproduction signal quality at the position, and a recording power determination unit for determining recording power for recording new data according to the reproduction signal quality detected by the reproduction signal detection unit. It is characterized by.

  According to the present invention, when new data is recorded on an optical disc from the interruption position where data recording was interrupted, the interruption position is detected by the interruption detection unit, and the reproduction signal quality at the interruption position is detected. Detect by part. As a result, the reproduction signal quality of the reproduced data is analyzed to determine whether or not the recording power has the optimum magnitude. When it is determined that the recording power is not an appropriate magnitude, the recording power determining unit adjusts the recording power so that the recording power is corrected to an optimum recording power. As a result, the optimum recording power can be determined according to the recording position of the disc, so that the signal quality can be improved.

  Here, the reproduction signal detection unit detects asymmetry as the reproduction signal quality at the interruption position. At this time, the recording power determination unit determines the recording power according to the asymmetry detected by the reproduction signal detection unit. Asymmetry indicates a positive value if the recording power is greater than the optimum recording power, and indicates a negative value if the recording power is less than the optimum recording power. Therefore, by detecting asymmetry, it can be determined whether or not the recording power is appropriate, and correction can be made so that the optimum recording power is obtained.

  Alternatively, the reproduction signal detection unit may detect the β value as the reproduction signal quality at the interruption position. The recording power determination unit determines the recording power according to the β value detected by the reproduction signal detection unit. The β value indicates a positive value if the recording power is greater than the optimum recording power, and indicates a negative value if the recording power is less than the optimum recording power. Therefore, by detecting the β value, it is possible to determine whether or not the recording power is appropriate, and it is possible to correct the recording power so that the optimum recording power is obtained.

  Further, the reproduction signal detection unit may detect a jitter value at the interruption position. The recording power determination unit determines the recording power according to the jitter value detected by the reproduction signal detection unit. The jitter value is a numerical value of the fluctuation of the signal waveform. The smaller the jitter value, the better the signal quality. Therefore, by measuring the jitter value, it is possible to determine whether the signal quality is good or bad, and based on the result, it is possible to correct the recording power so that the optimum recording power is obtained.

  The optical disc recording apparatus according to the present invention may further include a recording power storage unit that stores recording power in association with the recording position of the optical disc. Thereby, the recording power determination unit can also select the recording power by selecting from the recording powers stored in the recording power storage unit according to the interruption position. The recording power of new data can be determined, for example, by selecting the recording power when data is recorded at the position physically closest to the recording position of the new data from the recording power recording unit. . Thus, it is possible to record data with the optimum recording power without reproducing the data at the interruption position and determining the recording power each time data is recorded.

  According to another aspect of the present invention, a recording method for recording data on an optical disc is provided. According to such a recording method, an interruption step for interrupting data recording on the optical disc and a reproduction signal quality at the interruption position are detected when new data is continuously recorded from the interruption position where the data recording is interrupted. A reproduction signal quality detecting step, a recording power determining step for determining a recording power for recording new data according to the detected reproduction signal quality, and recording new data based on the determined recording power. And a recording step.

  As described above, according to the present invention, it is possible to provide an optical disc recording apparatus and a recording method capable of recording data with an optimum recording power in accordance with the recording position of the disc.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

(First embodiment)
First, an optical disk recording apparatus according to the first embodiment of the present invention will be described with reference to FIG. FIG. 3 is a configuration diagram showing the configuration of the optical disc recording apparatus 100 according to the present embodiment.

  The optical disc recording apparatus 100 according to the present embodiment includes an optical disc 110, a spindle motor 120, an optical pickup 130, an optical pickup driving unit 140, a driver IC 150, a signal processing DSP 160, a nonvolatile memory 170, and a buffer memory 180. And an interface unit 190.

  The optical disc 110 is a recording medium that uses laser light for data recording and reproduction, and includes, for example, DVD ± R and DVD ± RW.

  The spindle motor 120 is a drive unit for stably rotating the optical disc 110 at a predetermined speed when recording data on the optical disc 110. Further, the spindle motor 120 includes a mechanism for holding the optical disk 110.

  The optical pickup 130 is a functional unit that records data on the optical disc 110 and reproduces data recorded on the optical disc 110. The optical pickup 130 according to the present embodiment includes the functions of an interruption detection unit that detects a recording interruption position on the optical disc 110 and a reproduction signal detection unit that detects reproduction signal quality at the interruption position. For this reason, the optical pickup 130 includes, for example, a light source such as a laser diode and a light receiving element for detecting reflected light from the optical disk 110. The optical pickup 130 can detect the recording interruption position on the optical disc 110 and the reproduction signal quality by analyzing the reflected light from the optical disc 110 detected by the light receiving element. In addition, the optical pickup 130 includes an actuator for moving a light source, an objective lens, a lens, and the like to focus.

  The optical pickup driving unit 140 is a driving unit that moves the optical pickup 130 from the inner periphery to the outer periphery along the radius of the optical disc 110, and for example, a thread motor is used. The optical pickup driving unit 140 includes a shaft on which the optical pickup 130 is mounted and moved.

  The driver IC 150 is a functional unit for driving the spindle motor 120, the actuator of the optical pickup 130, and the optical pickup driving unit 140. The driver IC 150 drives each motor based on a control signal output from a signal processing DSP 160 described later.

  The signal processing DSP 160 is a functional unit that performs signal processing and control of the entire optical disc recording apparatus 100. In the present embodiment, the signal processing DSP 160 has a function of determining the optimum recording power according to the reproduction recording signal detected by the optical pickup 130. Further, the signal processing DSP 160, for example, an RF amplifier function for calculating a signal from the optical pickup 130, a servo control function for taking out a servo signal from the signal from the optical pickup 130 and performing servo control, taking out data from the reproduced signal, It has an encoder / decoder function that performs data modulation for recording, a microcomputer that controls these functions, and communicates with the outside of the optical disc recording apparatus 100. In the present embodiment, these functions are provided in the signal processing DSP 160, but the present invention is not limited to this example, and may be provided as independent components.

  The nonvolatile memory 170 is a storage unit for storing a microcomputer program and various setting values in the signal processing DSP 160, recording power data determined by OPC, recording power when data is actually recorded on the optical disc 110, and the like. is there. Here, the recording power when data is actually recorded on the optical disc 110 is stored in the nonvolatile memory 170 in association with the recording position of the optical disc 110 recorded with the recording power.

  The buffer memory 180 is a storage unit that temporarily stores data recorded on or reproduced from the optical disc 110 for input / output with the external device 200. In the present embodiment, the nonvolatile memory 170 and the buffer memory 180 are provided independently, but the present invention is not limited to such an example, and may be provided in, for example, the signal processing DSP 160 described above. .

  The interface unit 190 is a connection unit for connecting the optical disc recording apparatus 100 to an external device such as a computer or a video camera. The interface unit 190 is often applied with the ATAPI standard.

  Such an optical disc recording apparatus 100 is connected to an external device 200 such as a recording / playback back end via an interface unit 190, and outputs data from the external device 200 or inputs data to the external device 200. To do. Here, for example, when data such as video data and audio data is recorded on the optical disc 110 using the optical disc recording apparatus 100, the amount of data to be recorded is usually the actual data recording speed on the optical disc 110. Slower than. For this reason, the recording of data on the optical disc 110 is performed intermittently by stopping recording when a certain amount of data is recorded and restarting data recording after sufficient data has been accumulated.

  When intermittent recording is performed, the recording of data to be resumed is performed so as to be written at the interruption position of the optical disc 110 where the recording was interrupted immediately before. At this time, the optical disc recording apparatus 100 according to the present embodiment reads the asymmetry that is the reproduction recording quality at the interruption position and determines the optimum recording power when resuming the data recording when data writing is performed. Features.

  Next, based on FIG. 1 and FIG. 4, the recording method to the optical disk concerning this embodiment is demonstrated. FIG. 4 is a flowchart showing the optical disk recording method according to the present embodiment.

  In the optical disk recording method according to the present embodiment, first, when a recording start command is issued from the external device 200, the data to be recorded is temporarily stored in the buffer memory 180. When data is stored in the buffer memory 180, the optical disc recording apparatus 100 performs OPC to obtain the optimum recording power when recording data on the optical disc 110 (S101). As described above, the OPC is performed by the PCA 112, which is the test writing area, and the optimum recording power is thereby determined (S103).

  Next, the data stored in the buffer memory 180 is recorded in the recording area 111 of the optical disc 110 (S105). The recording area 111 of the optical disc 110 includes a PCA 112 and an area 113 outside the PCA 112 where data is actually stored. Data to be recorded first is recorded from, for example, the recording position A that is the innermost position of the area 113 in the recording area 111. Here, when the amount of data to be recorded per time is slower than the actual data recording speed on the optical disc 110, recording on the optical disc 110 is stopped when a certain amount of data stored in the buffer memory 180 is recorded. (S107). For example, assume that data is recorded from the recording position A to the recording position B in one recording. In this case, the recording position B becomes the interruption position.

  When the data recording is interrupted, it is determined whether or not to record more data (S109). Such a determination can be made based on, for example, whether data is stored in the buffer memory 180 and whether a recording stop command is issued from the external device 200. If there is no data stored in the buffer memory 180 and a recording stop command is issued, the recording power at the interruption position where the data recording is interrupted is recorded at the address, and the recording is stopped (S111).

  On the other hand, when data is continuously recorded because the data is stored in the buffer memory 180 or the recording stop command is not issued from the external device 200, the data is first connected. Data is reproduced from a recording position slightly before the interrupted position (S113). For example, when data is recorded from the interruption position B, the optical pickup 130 of the optical disk recording apparatus 100 is moved from the interruption position B to the inside (rotation center side of the optical disk 110) by the optical pickup driving unit 140 to the position B ′. The data can be reproduced from the recording position B ′ slightly before the interruption position B. In this case, it is only necessary to reproduce data from the position B ′ to the position B to reproduce several frames, for example, about 2 to 4 frames, and to read a fraction of the frames.

  Next, asymmetry at the interruption position is detected by the optical pickup 130 from the data reproduced in step S113 (S115). The measurement of asymmetry in step S115 can be performed, for example, by the same process as that in the above-described OPC operation.

  When the asymmetry is detected in step S115, the optical disc recording apparatus 100 checks the size of the detected asymmetry (S117). Asymmetry, as described above, represents a deviation in the objectivity of a signal obtained by reproducing a recording signal, and is a measure of recording power quality. Generally, when the asymmetry is large, the recording power is excessively low, and when the asymmetry is small, the recording power is excessively large.

  Here, the relationship between asymmetry and recording power will be described in detail with reference to FIGS. 5A to 5C and FIGS. 6A to 6C. 5A to 5C are graphs schematically showing RF signals for explaining asymmetry. FIG. 5A shows a case where the recording power is low, and FIG. 5B shows a case where the recording power is the optimum power. FIG. 5C shows a case where the recording power is large. 6A to 6C are graphs showing the waveform of the RF signal. FIG. 6A shows a case where the recording power is low, FIG. 6B shows a case where the recording power is the optimum power, and FIG. 6C shows a case where the recording power is high. Indicates. 6A to 6C show the opposite tendency to FIGS. 5A to 5C because the polarities of the measurement signals are reversed from those of FIGS. 5A to 5C.

  First, the asymmetry is expressed by the following mathematical formula 1.

Here, I ₁ represents the amplitude of the reproduction signal of T 1 that is the longest recording length on the optical disc 110. Here, I ₁ = I _1H −I _1L , where I _1H is the maximum level and I _1L is the minimum level. I ₂ represents the magnitude of the reproduction signal of T2, which is the shortest recording length on the optical disc 110. Here, I ₂ = I _2H −I _2L , where I _2H is the maximum level and I _2L is the minimum level. As shown in Equation 1, asymmetry represents the ratio of the difference between the average DC level of the longest recording length and the average DC level of the shortest recording length to the size of the maximum recording length.

  The asymmetry is determined based on the level of return light from the optical disc 110. In the graphs shown in FIGS. 5A to 5C, the value when there is no reflected light from the optical disk 110 is set to zero. For this reason, all signals are positive values. Data is recorded on the optical disk 110 by forming pits on the optical disk 110 that is a mirror surface to reduce light reflection. Therefore, since the return light from the optical disk 110 is small in a long pit that can easily form a pit even if the recording power is low, the level of the return light approaches zero. On the other hand, short pits are difficult to form when the recording power is low, so that the return light from the optical disk 110 is not sufficiently small, and the average level is high.

  As described above, when the recording power is smaller than the optimum recording power, the average DC level value of the shortest recording length is increased as shown in FIG. 5A. For this reason, the difference between the average DC level of the longest recording length and the average DC level of the shortest recording length is a negative value, and the asymmetry is also a negative value. At this time, as shown in FIG. 6A, the actual RF signal is shifted downward as a whole (because the polarity of the measurement signal is reversed from that in FIG. 5A).

  When the recording power is equal to the optimum recording power, as shown in FIG. 5B, there is almost no difference between the average DC level of the longest recording length and the average DC level of the shortest recording length. It becomes a waveform. At this time, the asymmetry is zero. At this time, as shown in FIG. 6B, the waveform of the actual RF signal is substantially vertical.

  When the recording power is larger than the optimum recording power, the average DC level value of the shortest recording length is lowered as shown in FIG. 5C. Therefore, the difference between the average DC level of the longest recording length and the average DC level of the shortest recording length is a positive value, and the asymmetry is also a positive value. At this time, as shown in FIG. 6C, the actual RF signal is generally on the upper side (because the polarity of the measurement signal is reversed from that in FIG. 5C).

  From such a relationship between the recording power and the asymmetry, when the asymmetry is larger than 0, the recording power is set smaller than the recording power at the interruption position by a predetermined value (S119). For example, when the asymmetry at the interruption position B is greater than 0, it is determined that the recording power at the interruption position B is greater than the optimum recording power. Therefore, the recording power when recording data to be written at the interruption position B is set to be smaller by a predetermined value ΔP than the recording power at the interruption position B so as to approach the optimum recording power.

  When the predetermined value of asymmetry is smaller than 0, the recording power is set larger than the recording power at the interruption position by a predetermined value (S121). For example, when the asymmetry at the interruption position B is smaller than 0, it is determined that the recording power at the interruption position B is smaller than the optimum recording power. Therefore, the recording power when recording the data to be written at the interruption position B is set larger by a predetermined value ΔP than the recording power at the interruption position B so as to approach the optimum recording power.

  When the asymmetry is 0, the recording power at the interruption position B is almost equal to the optimum recording power. Therefore, the recording power for recording data to be written at the interruption position B is set to the same value as the recording power at the interruption position B.

  As described above, when the recording power for recording new data is set in steps S119 and S121, the process returns to step S105 to record the data.

  In this embodiment, the recording power is corrected based on the result of determining whether the asymmetry is 0, larger than 0, or smaller. However, the present invention is not limited to this example. If the asymmetry is within a predetermined value ± α (for example, within ± 2%), the recording power is set to be the same as that immediately before, and if it is larger than α (for example, 2%), the recording power is set small by a predetermined value, and −α (for example, -2%), the recording power may be set larger by a predetermined value. Further, the correction amount of the recording power may be changed according to the asymmetry size. Thereby, the recording power can be made closer to the optimum recording power.

  The optical disk recording method according to the present embodiment has been described above. According to this method, the recording power is corrected based on asymmetry every time data writing is performed. As a result, it is possible to correct the shift in the optimum recording power that occurs due to the difference in the recording position of the optical disk 110. In this method, the recording power when data is written is determined based on the signal recorded immediately before the actual recording position on the optical disc 110. As described above, by using the actually used signal, it is possible to perform correction with higher accuracy than the normal R-OPC technique. Therefore, the recording method of this embodiment can also be applied to a phase change type disc for which no R-OPC method has been developed.

(Second Embodiment)
Next, an optical disk recording method according to the second embodiment of the present invention will be described with reference to FIGS. The optical disk recording method according to the present embodiment is different from the first embodiment in that the β value is detected by an optical pickup instead of asymmetry and the recording power for recording data on the optical disk is determined. To do. The optical disk recording method according to the present embodiment will be described below, but detailed description of the same processing as that of the optical disk recording method according to the first embodiment will be omitted. FIG. 7 is a flowchart showing the optical disk recording method according to the present embodiment. 8A to 8C are graphs schematically showing an RF signal for explaining the β value. FIG. 8A shows a case where the recording power is low, and FIG. 8B shows a case where the recording power is the optimum power. 8C shows the case where the recording power is large. An optical disc apparatus 100 to which the optical disc recording method according to the present embodiment is applied has the same configuration as that shown in FIG.

  In the optical disk recording method according to the present embodiment, the processes of steps S201 to S213 are performed in the same process as steps S101 to S113 of the optical disk recording method according to the first embodiment.

  Next, the β value at the interruption position is detected by the optical pickup 130 from the data reproduced in step S213 (S215). The measurement of the β value in step S215 is performed in the same manner as the asymmetry measurement described in the first embodiment.

  Here, the β value is a value represented by Equation 2 below.

A ₁ and A ₂ represent the amplitude of the reproduction signal of T1, which is the longest recording length when the reproduction signal of the optical disc 110 is AC-coupled. A ₁ is the maximum level, and A ₂ is the minimum level. As shown in Equation 2, the β value represents the ratio of the average level of the longest recording length to the average level of all the reproduction signals with respect to the magnitude of the amplitude, and is an alternative to asymmetry.

The β value is calculated from the result of AC coupling of the reproduction RF signal that is the return light from the optical disc 110. As a result of AC coupling of the reproduction RF signal, the average level of all signals is 0, A ₁ is a positive value, and A ₂ is a negative value. Therefore, if the waveform of the reproduction RF signal is a vertical target, the β value is 0. Similar to asymmetry, when the recording power of data on the optical disk 110 is low, the β value is positive because the average level is high for short pits, and is negative because the average level is low for long pits.

  When the β value is detected in step S215, the magnitude of the detected β value is checked (S217). The β value represents a deviation in objectivity of a signal obtained by reproducing a recorded signal (reproduced RF signal), and is a measure of recording power quality. In general, when the β value is large, the recording power is too small, and when the β value is small, the recording power is excessive.

  That is, when the recording power is smaller than the optimum recording power, as shown in FIG. 8A, the average DC level value of the longest recording length is low, and the β value is a negative value. When the recording power is equal to the optimum recording power, as shown in FIG. 8B, the average DC level of the longest recording length is almost 0, and the reproduced RF signal has a vertically symmetrical waveform. At this time, the β value becomes zero. When the recording power is larger than the optimum recording power, as shown in FIG. 8C, the average DC level value of the longest recording length is high, and the β value is a positive value.

  Therefore, when the β value is larger than 0, the recording power is set smaller than the recording power at the interruption position by a predetermined value (S219). For example, if the β value at the interruption position B is greater than 0, it is determined that the recording power at the interruption position B is greater than the optimum recording power. Therefore, the recording power when recording data to be written at the interruption position B is set to be smaller by a predetermined value ΔP than the recording power at the interruption position B so as to approach the optimum recording power.

  On the other hand, when the β value is smaller than 0, the recording power is set larger than the recording power at the interruption position by a predetermined value (S221). For example, when the β value at the interruption position B is smaller than 0, it is determined that the recording power at the interruption position B is smaller than the optimum recording power. Therefore, the recording power when recording the data to be written at the interruption position B is set larger by a predetermined value ΔP than the recording power at the interruption position B so as to approach the optimum recording power.

  When the β value is 0, the recording power at the interruption position B is almost equal to the optimum recording power. Therefore, the recording power for recording data to be written at the interruption position B is set to the same value as the recording power at the interruption position B.

  As described above, when the recording power for recording new data is set in steps S219 and S221, the process returns to step S205 to record the data.

  The optical disk recording method according to the present embodiment has been described above. According to this method, the recording power is corrected based on the beta value every time data writing is performed. As a result, it is possible to correct the shift in the optimum recording power that occurs due to the difference in the recording position of the optical disk 110. In this method, the recording power when data is written is determined based on the signal recorded immediately before the actual recording position on the optical disc 110. As described above, by using the actually used signal, it is possible to perform correction with higher accuracy than the normal R-OPC technique. Therefore, the recording method of this embodiment can also be applied to a phase change type disc for which no R-OPC method has been developed.

(Third embodiment)
Next, an optical disk recording method according to the third embodiment of the present invention will be described with reference to FIG. The optical disk recording method according to this embodiment is different from the first embodiment in that a jitter value is detected by an optical pickup instead of asymmetry and a recording power for recording data on the optical disk is determined. To do. The optical disk recording method according to the present embodiment will be described below, but detailed description of the same processing as that of the optical disk recording method according to the first embodiment will be omitted. FIG. 9 is a flowchart showing the optical disk recording method according to the present embodiment. An optical disc apparatus 100 to which the optical disc recording method according to the present embodiment is applied has the same configuration as that shown in FIG.

  In the optical disc recording method according to the present embodiment, the processes of steps S301 to S313 are the same as steps S101 to S113 of the optical disc recording method according to the first embodiment.

  Next, the jitter value at the interruption position is detected by the optical pickup 130 from the data reproduced in step S313 (S315). The jitter value is expressed by the standard deviation of the time change of the data digitized after being equalized. The actual waveform of the RF signal shows an eye pattern as shown in FIG. 6B, for example. The jitter value is a numerical value of the shake of the edge of the eye pattern. The smaller the jitter value, that is, the more uniform the interval between the edges of the eye pattern, the better the signal quality.

  The relationship between the jitter value and the signal quality can also be recognized from FIGS. When the recording power is low, as shown in FIG. 6A, the eyes of the eye pattern are blurred and the edge shake is large. On the other hand, when the recording power is the optimum value, as shown in FIG. 6B, the eyes of the eye pattern are clearly open and the edge shake is small. When the recording power is high, as shown in FIG. 6C, the eye of the eye pattern is blurred and the edge shake is large. Thus, when the recording power is too low or too high, that is, when the signal quality is not good, the edge shake is large and the jitter value is large. On the other hand, when the recording power is optimum, that is, when the signal quality is good, the edge shake is small and the jitter value is small.

  Therefore, the jitter value is measured in step S315, and the magnitude of the jitter value is determined (S317). When the jitter value measured in step S317 is smaller than the previously measured data jitter value, it is determined that the recording power is the optimum value, and the next data is recorded without correcting the recording power. On the other hand, when it is larger than the jitter value of the data measured last time, it is determined that the recording power is not appropriate, and the recording power is corrected.

  Here, it is possible to recognize whether the signal quality is good or bad from the jitter value, but it is not possible to determine whether the recording power is too low or too high. For this reason, in the recording method according to the present embodiment, the RF level of the RF signal of the data recorded immediately before is measured (S319). The RF level is the amplitude of the RF signal. When the RF level is large, the recording power is excessive, and when the RF level is small, the recording power tends to be excessive. Therefore, it is determined whether or not the RF level is higher than the reference value (S321), and the recording power is corrected based on the determination result. That is, when the RF level is smaller than the reference value, the recording power is increased by a predetermined value ΔP (S323). On the other hand, if the RF level is higher than the reference value, the recording power is decreased by a predetermined value ΔP (S325).

  As described above, when the recording power for recording new data is set in steps S317, S323, and S325, the process returns to step S305 to record the data.

  The optical disk recording method according to the third embodiment has been described above. According to this method, the recording power is corrected based on the jitter value every time data writing is performed. As a result, it is possible to correct the shift in the optimum recording power that occurs due to the difference in the recording position of the optical disk 110. In this method, the recording power when data is written is determined based on the signal recorded immediately before the actual recording position on the optical disc 110. As described above, by using the actually used signal, it is possible to perform correction with higher accuracy than the normal R-OPC technique. Therefore, the recording method of this embodiment can also be applied to a phase change type disc for which no R-OPC method has been developed.

(Fourth embodiment)
Next, an optical disk recording method according to the fourth embodiment of the present invention will be described with reference to FIG. The optical disc recording method according to the present embodiment is different from the first embodiment in that it is checked whether or not it is appropriate to correct the recording power using the jitter value. The optical disk recording method according to the present embodiment will be described below, but detailed description of the same processing as that of the optical disk recording method according to the first embodiment will be omitted. FIG. 10 is a flowchart showing the optical disc recording method according to the present embodiment. An optical disc apparatus 100 to which the optical disc recording method according to the present embodiment is applied has the same configuration as that shown in FIG.

  In the optical disc recording method according to the present embodiment, the processes of steps S401 to S415 are the same as steps S101 to S115 of the optical disc recording method according to the first embodiment.

  Next, in the optical disk recording method according to the present embodiment, the jitter value of the reproduction signal is measured (S417). As described above, the smaller the jitter value, the better the signal quality. Therefore, in this embodiment, a jitter value is used as an index for checking whether or not it is appropriate to perform recording power correction.

  Thereafter, the size of the asymmetry detected in step S415 is checked to determine whether or not the recording power needs to be corrected (S419). The check in step S419 is the same as the process in step 117 in the first embodiment. When the asymmetry size is 0, new data is recorded without correcting the recording power.

  On the other hand, if the asymmetry is greater than 0, it is checked whether the jitter value of the data recorded immediately before is worse than the jitter value measured last time (S421). If the jitter value has deteriorated, it is determined that the signal quality has deteriorated, and the recording power is reduced by a predetermined value ΔP (S423). If it is determined in step S421 that the jitter value has not deteriorated, new data is recorded without correcting the recording power.

  Even when the asymmetry is smaller than 0, it is checked whether or not the jitter value of the data recorded immediately before is worse than the previously measured jitter value (S425). If the jitter value has deteriorated, it is determined that the signal quality has deteriorated, and the recording power is increased by a predetermined value ΔP (S427). When it is determined in step S425 that the jitter value has not deteriorated, new data is recorded without correcting the recording power.

  In this manner, when the recording power for recording new data is set in steps S419, S427, and S429, the process returns to step S405, and data recording is performed.

  The optical disk recording method according to the fourth embodiment has been described above. According to this method, the recording power is corrected based on asymmetry every time data writing is performed. As a result, it is possible to correct the shift in the optimum recording power that occurs due to the difference in the recording position of the optical disk 110. Further, by checking whether or not it is appropriate to correct the recording power using the jitter value, the recording power can be corrected more appropriately. Further, in such a method, the recording power when data is written is determined based on a signal recorded immediately before the actual recording position of the optical disc 110. As described above, by using the actually used signal, it is possible to perform correction with higher accuracy than the normal R-OPC technique. Therefore, the recording method of this embodiment can also be applied to a phase change type disc for which no R-OPC method has been developed.

  In the second embodiment, it may be checked whether or not the recording power correction is performed based on the jitter value as in the present embodiment.

(Fifth embodiment)
Next, an optical disk recording method according to the fifth embodiment of the present invention will be described with reference to FIG. In the optical disk recording method according to the present embodiment, the recording power determined by the methods of the first to fourth embodiments is stored in the storage unit, and the recording power when recording new data is stored in the storage unit. Is selected from the recording power stored in the memory. The optical disk recording method according to the present embodiment will be described below, but detailed description of the same processing as that of the optical disk recording method according to the first embodiment will be omitted. FIG. 11 is a flowchart showing the optical disc recording method according to the present embodiment. An optical disc apparatus 100 to which the optical disc recording method according to the present embodiment is applied has the same configuration as that shown in FIG.

  First, when the recording power for recording data on the optical disc 110 is determined by the methods of the first to fourth embodiments, the optical disc recording apparatus 100 stores the recording position in the storage unit such as the nonvolatile memory 170, for example. The address and recording power are stored.

  Next, in the case where new data is written and recorded on the already recorded data, first, the data recording position is detected (S501). The recording position can be specified by the address of the optical disc 110, and the recording position can be detected by the optical pickup 130.

  When the recording position is detected, the optical disc recording apparatus 100 selects the recording power when data is recorded at the position closest to the recording position from the plurality of recording powers stored in the storage unit (S503). The process of step S503 searches, for example, an address physically close to the address of the recording position of the optical disc 110 detected in step S501 from the nonvolatile memory 170, and selects the recording power associated with the searched address. Can be performed. Then, new data is recorded using the recording power selected in step S503 (S505).

  As described above, in the optical disc recording method according to the present embodiment, the optimum recording power can be obtained even on an optical disc having a large sensitivity unevenness by recording new data using the recording power used at a physically close position. Can record data. Further, it is not necessary to determine the recording power by reproducing the data at the interruption position each time data is recorded.

  In the above description, the recording power associated with the address closest to the address of the recording position for recording new data is the recording power for recording new data. However, the present invention is not limited to such an example. For example, the recording area of the optical disk 110 is divided, the optimum recording power in each recording area is stored in a storage unit such as the nonvolatile memory 170, and the optimum recording power of the recording area including the recording position for recording new data is used. New data can also be recorded.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  For example, in the above embodiment, the recording power is corrected by a predetermined value regardless of the level of the reproduction signal quality, but the present invention is not limited to such an example. For example, the recording power correction amount may be adjusted according to the magnitude of the reproduction signal quality. As a result, data can be recorded with a more optimal recording power.

It is explanatory drawing for demonstrating the recording position of an optical disk. It is explanatory drawing for demonstrating asymmetry measurement, (a) is a graph which shows the relationship between recording power and asymmetry, (b) is a table | surface which shows the recording power and asymmetry in the recording position of data. 1 is a configuration diagram showing a configuration of an optical disc recording apparatus according to a first embodiment of the present invention. 3 is a flowchart showing an optical disc recording method according to the embodiment. It is the graph which showed typically RF signal in case recording power is small for demonstrating asymmetry. It is the graph which showed typically RF signal in case recording power is the optimal power for demonstrating asymmetry. It is the graph which showed typically RF signal in case recording power is large for demonstrating asymmetry. It is the graph which showed the waveform of RF signal when recording power is small. It is the graph which showed the waveform of RF signal in case recording power is optimal power. It is the graph which showed the waveform of RF signal when recording power is large. It is a flowchart which shows the optical disk recording method concerning the 2nd Embodiment of this invention. It is the graph which showed typically RF signal in case recording power is small for explaining beta value. It is the graph which showed typically RF signal in case recording power is optimal power for explaining beta value. It is the graph which showed typically RF signal in case recording power is large for explaining beta value. It is a flowchart which shows the optical disk recording method concerning the 3rd Embodiment of this invention. It is a flowchart which shows the optical disk recording method concerning the 4th Embodiment of this invention. It is a flowchart which shows the optical disk recording method concerning the 5th Embodiment of this invention.

Explanation of symbols

100 Optical Disc Recording Device 110 Optical Disc 112 PCA
120 Spindle motor 130 Optical pickup 140 Optical pickup driver 150 Driver IC
160 Signal processing DSP
170 Nonvolatile memory 180 Buffer memory 190 Interface unit 200 External device

Claims (6)

An optical disk recording apparatus for recording data on an optical disk,
An interruption detecting unit for detecting an interruption position at which recording of data on the optical disc is interrupted;
A data recording unit for recording new data continuously to the data recorded on the optical disc;
A reproduction signal detector for detecting reproduction signal quality at the interruption position;
A recording power determination unit for determining a recording power for recording the new data according to the reproduction signal quality detected by the reproduction signal detection unit;
An optical disc recording apparatus comprising: The reproduction signal detection unit detects asymmetry at the interruption position,
2. The optical disc recording apparatus according to claim 1, wherein the recording power determination unit determines the recording power according to asymmetry detected by the reproduction signal detection unit. The reproduction signal detection unit detects a β value at the interruption position,
2. The optical disk recording apparatus according to claim 1, wherein the recording power determination unit determines the recording power according to the β value detected by the reproduction signal detection unit. The reproduction signal detection unit detects a jitter value at the interruption position,
4. The optical disc recording apparatus according to claim 1, wherein the recording power determination unit determines the recording power according to a jitter value detected by the reproduction signal detection unit. A recording power storage unit that stores recording power in association with the recording position of the optical disc;
2. The optical disc recording according to claim 1, wherein the recording power determination unit selects the recording power by selecting from the recording powers stored in the recording power storage unit according to the interruption position. apparatus. An optical disc recording method for recording data on an optical disc,
An interruption step of interrupting recording of data on the optical disc;
A reproduction signal quality detection step of detecting reproduction signal quality at the interruption position when recording new data continuously from the interruption position where the recording of the data was interrupted;
A recording power determining step for determining a recording power when recording the new data according to the detected reproduction signal quality;
A recording step of recording the new data based on the determined recording power;
An optical disc recording method comprising:

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