JP2005071533A - Optical disk device and its recording/reproducing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of the possible shifting of data recording power decided by trial writing in the test track of a recording medium, e.g., an optical disk from the optimal value of original data recording power caused by damage or dusts on the test track or noise superposed during recording in a conventional optical disk device. <P>SOLUTION: The optical disk device for recording/reading and reproducing information on/from an optical disk 2 by a laser beam 5 emitted from a semiconductor laser 8 performs trial writing in the test area of the optical disk 2 before the information is recorded by the laser beam 5, sets the temporary power of a recording laser beam, performs recording by a recording laser beam 5 changed to an upper or lower limit in a predetermined width with respect to the temporary power of the recording laser beam 5, determines the permission of normal recording by the reading checking, and corrects a driving signal fed to a semiconductor laser 5 to enable normal recording in the predetermined width of the temporary power setting of the recording laser beam. Its recording/reproduction method is provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical disc apparatus with improved data recording power setting and a recording / reproducing method thereof.

  2. Description of the Related Art Generally, as an apparatus for recording information, an optical disk apparatus that optically records information using an optical disk as a recording medium is known. When the optical disk is, for example, a 3.5-inch magneto-optical disk, a high-density recording medium of about 230 MB to 540 MB or 640 MB is used.

  Normally, when writing information to a magneto-optical disk, the optimum data recording power for each medium is different, so when the medium is loaded, trial writing is performed for each zone to obtain the optimum data recording power. The flash adjustment is adjusted.

  For example, in Patent Document 1 proposed by the applicant of the present invention, data is written by sequentially changing the data recording power in the test area on the recording medium by the laser control means, and the data in the test area is written by the amplitude measuring means. The data recording power is calculated by measuring the amplitude of the reproduction signal and calculating the data recording power that the recording power calculation means actually uses based on the power value when the amplitude measurement result falls within a predetermined range. A technique for setting the value with high accuracy is disclosed.

Specifically, first, trial writing is performed on a recording medium with a predetermined test recording power, and the information signal is read. If the amplitude of the read signal is within a specified value, a predetermined coefficient (α1˜ The value multiplied by αn) is used as the actual data recording power. If the data recording power write does not cause an error at the time of recording confirmation (verification), it is determined to be normal. Such trial writing is performed in the minimum zone and the maximum zone (inner and outer sides of the recording medium), and the data recording power of other zones is determined by performing linear approximation on the calculated data recording power. doing.
JP 2000-20955 A, paragraph numbers [0025] to [0034].

  In Patent Document 1 described above, information is recorded with the data recording power determined by trial writing, the information is read and confirmed, and the data recording power is assumed to be normal. Therefore, since the data recording power itself is not measured, it cannot be confirmed whether recording is actually performed with the optimum data recording power. Such data recording realizes proper data recording in a state in which the recording surface (track or sector) is not damaged and there is no noise that affects the recording surface. However, since an optical disc on which information can be rewritten and recorded is used by a user after information has been written once, there is a possibility that a large or small scratch or the like may have been made on the disc surface before being written again.

  Therefore, when the sector used for trial writing has scratches, dents, or foreign matter such as dust, or when external writing is superimposed on the test recording power and trial writing has not been performed normally. May not be able to cope with, and may deviate from the optimum value of the original data recording power.

  For example, when normal test writing is performed, as shown in FIG. 5A, the optimum data recording power is determined from the DUTY signal and the amplitude detection signal in the reproduction signal of the recorded information. On the other hand, as shown in FIG. 5B, when the sector is scratched or noise is superimposed, the amplitude detection signal and the DUTY detection signal are affected. If amplitude detection or DUTY detection is performed in a portion where this influence has occurred, an incorrect result will be detected. If the data recording power is determined based on an erroneous result obtained in the trial writing, there arises a problem that the original optimum data recording power is deviated. Even if the optimum data recording power is deviated, there is no problem as long as it is within the margin of normal writing. However, this margin is not confirmed and written.

  In particular, a recording medium such as a rewritable (overwrite) type optical disk has low durability due to high power, and there is a possibility that the recording surface may be destroyed when a data recording power exceeding a specified level is applied. For example, in a recording medium such as a magneto-optical disk, an initialization layer magnetized in the erase direction is provided, and a recording layer is provided thereon. When the data recording power is deviated from the optimum value, the initialization layer is exposed to an excessive data recording power and is magnetized in the recording direction. As a result, overwriting (or rewriting) cannot be performed.

  Accordingly, the present invention provides an optical disc apparatus that enables data recording with a margin for changes due to scratches on the recording surface and external noise by optimizing the data recording power for recording information on the optical disc. An object of the present invention is to provide a recording / reproducing method.

In order to achieve the above object, according to the present invention, firstly, in an optical disc apparatus for recording information on an optical disc or reading and reproducing recorded information by a recording or reproducing laser beam emitted from a semiconductor laser,
Before recording information with the recording laser beam, trial writing is performed on the test area of the optical disc, the power of the temporary recording laser beam is set, and the power of the temporary recording laser beam is set to a predetermined value. The trial writing data changed to the upper limit side and the lower limit side within the width is recorded, and whether or not normal recording is possible by checking these readings is detected. Provided is an optical disc apparatus including a control unit that corrects the setting of light power so that normal recording is performed within the predetermined width.

  Second, a semiconductor laser that emits a recording or reproducing laser beam, laser driving means for supplying a reproducing current and a recording current to the semiconductor laser, and recorded information recorded on a recording medium are stored in the semiconductor In an optical disk apparatus having information reproducing means for reading and reproducing recorded information using reproduction light from a laser, performing test writing in a test area on a recording medium, and setting the write power of laser light at the time of data recording, With respect to the data recording power determined by the trial writing, information is recorded by changing the data recording power, and based on the result of reproducing the recorded information, the data recording power determined by the trial writing is normally Provided is an optical disc apparatus that checks whether data is recorded and, if not normal, corrects the data recording power determined by trial writing.

  Further, in the recording / reproducing method of the optical disc in which information is recorded on the optical disc or read out and reproduced by the recording or reproducing laser beam emitted from the semiconductor laser, before the information is recorded by the recording laser beam, A test writing process for performing test writing to the test area of the optical disc, and the power of the temporary recording laser beam are set, and the power of the temporary recording laser beam is set to an upper limit side and a lower limit side within a predetermined width. The test writing data that has been changed is recorded, and a detection process for detecting whether or not normal recording is possible by confirming these readings, and if normal recording is impossible in the detection process, the temporary recording data There is provided an optical disk recording / reproducing method comprising: a correction step of correcting the setting of laser light power so that normal recording is performed within the predetermined width.

  Further, in the recording / reproducing method of the optical disc in which information is recorded on the optical disc or read out and reproduced by the recording or reproducing laser beam emitted from the semiconductor laser, before the information is recorded by the recording laser beam, A test writing to the test area of the optical disc to set the power of the temporary recording laser beam, and a first recording laser beam lower than the power of the temporary recording laser beam within a predetermined width A step of performing the first recording for recording the test writing data with the power of the first recording, and when the first recording is impossible, the first correction for setting the power higher than the lower limit side is performed and the re-recording is performed. Test writing data by the power of the second recording laser light whose settings are further corrected so that the lower limit side is sequentially set when the first recording is normal. A method for recording and reproducing an optical disk, comprising: a step of performing a second recording for recording a recording medium; and a step of setting a power of the temporary recording laser beam when the second recording is disabled. To do.

  The optical disc apparatus having the above-described configuration and the recording / reproducing method thereof have the data recording power Pw changed to the upper and lower recording powers within a predetermined width with respect to the provisional data recording power Pw obtained by trial writing. After recording, whether or not normal recording is possible by reading confirmation is measured, and the data recording power Pw is corrected so that normal recording is performed within a predetermined width. The upper limit side and the lower limit side within the predetermined width are the upper limit margin and the lower limit margin for the power of the recording laser beam.

  In addition, with respect to the provisional data recording power Pw obtained by the trial writing, the first lower limit recording power within the predetermined width and the lower second lower limit data recording power are used for recording, and then read confirmation is performed. Whether normal recording is possible is measured, and the data recording power Pw is corrected so that normal recording is performed within a predetermined width. The margin based on the first lower limit within the predetermined width is further guaranteed by the second lower limit margin.

  According to the present invention, an optical disc apparatus that enables data recording with a margin for changes due to the influence of scratches on the recording surface and external noise by optimizing the data recording power for recording information on the optical disc And a recording / reproducing method thereof.

  The present invention secures (confirms) a margin by correcting the data recording power determined by trial writing, thereby eliminating writing to the optical disk with high data recording power and preventing destruction of the optical disk. Thus, stable data recording can be realized.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a conceptual configuration example of an optical disc apparatus according to the present invention.

  The optical disc apparatus 1 includes a recording medium on which information can be rewritten and recorded (overwrite), for example, an optical disc 2, a spindle motor 3 that rotationally drives the optical disc 2, and a loading mechanism 4 that mounts the optical disc 2 on the spindle motor 3. , An optical pickup 6 for writing / reading data to / from the optical disc 2 with the laser beam 5, a moving mechanism 7 for moving the optical pickup 6 in the radial direction of the optical disc 2, and a laser diode (LD) for emitting the laser beam 5. 8, a photodetector (PD) 9 that receives the reflected laser light, a laser drive circuit 10 that drives the laser diode 8, an information reproducing circuit 11 that shapes and binarizes the output signal of the photodetector 9, and components The control unit 12 performs overall control and information processing.

  The control unit 12 further includes a laser control circuit 12 a that controls the laser driving circuit 10 and an information processing circuit 12 b that performs processing such as demodulation and error correction on the information signal from the information reproduction circuit 11.

  The optical disk 2 is preferably a magneto-optical disk capable of rewriting and recording information. In the present embodiment, information rewrite recording is described as an example, but it can also be applied to write-once recording.

  The optical pickup 6 includes a laser diode 8 and a photodetector 9 and is moved by a moving mechanism 7 in the radial direction of the optical disc 2, and the laser diode 8 irradiates a predetermined position (sector) of the optical disc 2 with the laser beam 5. The reflected light is received by the photodetector 9. The laser diode 8 irradiates the laser beam 5 with current supplied from the laser driving circuit 10 to the laser diode 8 in accordance with an instruction from the laser control circuit 12a.

  The photodetector 9 generates a signal based on the reflected light from the optical disc 2 and outputs the signal to the information reproducing circuit 11. The information reproducing circuit 11 performs processing such as waveform shaping and binarization on the output signal of the photodetector 9. The signal processed in the information reproducing circuit 11 is sent to the information processing circuit 12b. In this information processing circuit 12b, the signal from the information reproducing circuit 11 is subjected to processing such as demodulation and error correction, and the data recorded on the optical disc 2 is read out. The read data is sent to the host computer 13 and various processes are performed by the user.

  A data recording operation in the optical disc apparatus configured as described above will be described with reference to the flowchart shown in FIG. 2. This data recording operation is mainly performed under the control of the control unit 12.

  As shown in FIG. 1, after the optical disk 2 is mounted on the spindle motor 3 by the loading mechanism 4, the optical pickup 6 is moved to a track (test track or the like) of the optical disk 2 on which trial writing is performed under the control of the control unit 12 ( Step S1).

  First, an initial value (data for trial writing) determined by design and experience is set as the test recording power, and trial writing is performed on the test track. Thereafter, the test writing data is read by the pickup 6, and a temporary data recording power Pw is set based on the read value (step S2). This setting is performed using, for example, a table that is stored in advance in a memory (not shown) built in the control unit 12 and associates the read value with the temporary data recording power Pw.

  Next, it is checked whether the temporary data recording power Pw has a margin on the lower limit side and corrected. That is, the provisional data recording power is multiplied by 0.9, and the test writing data is recorded on the test track (step S3).

  Here, FIG. 3 shows the relationship between the data recording power and the error rate (error rate), which are judgment criteria. Since the position of Pmax varies depending on the spot diameter of the laser beam and the characteristics of the recording medium, it is desirable to perform recording with a data recording power that secures a margin of 10 to 30% from the lower limit value Pmin. Therefore, normal recording can be performed with a recording power 0.9 times the temporary data recording power Pw. In other words, it suggests that the margin is 10% on the lower limit side. Of course, this 0.9 times is a numerical value that is adjusted by the margin.

  Whether or not the recording is normally performed even with the data recording power Pw multiplied by 0.9 is verified (reading confirmation) to determine whether or not it is good (step S4). If this verification is not good (NO), it is determined that the power value is too low. Therefore, the provisional data recording power Pw that has become impossible is corrected to a new data recording power Pw that is 1.1 times larger (step S5). It is determined whether or not the new data recording power Pw exceeds a preset value, for example, an upper limit value Pmax (step S6). If the upper limit value Pmax is exceeded (YES), error processing is performed (step S6). Step S7).

  However, in step S6, if the new data recording power Pw does not exceed the upper limit value Pmax (YES), as in step S3, the disabled data recording power Pw is multiplied by 0.9 to obtain new data. Test writing data is recorded on the test track as the recording power Pw (step S8), and the process returns to step S4.

  Further, if the verification in the recording with the data recording power Pw multiplied by 0.9 is good in the determination in the step S4 (YES), it indicates that a 10% margin is provided on the lower limit side. doing.

  Next, the data recording power Pw determined to be normal (verify OK) in step S4 is multiplied by 1.1 to perform recording (step S9). Whether or not the recording with the data recording power Pw multiplied by 1.1 is normally recorded is verified to determine whether or not it is satisfactory (step S10). If this verification is not good (NO), it is determined that the power value is too high. Therefore, the data recording power Pw that has become impossible is multiplied by 0.9 and corrected as a new data recording power Pw (step S11). The new data recording power Pw is determined whether or not it falls below a preset value, for example, a lower limit value Pmin (step S12). If it falls below the lower limit value Pmin (YES), the process proceeds to step S7. Error handling. However, if the new data recording power Pw is not lower than the lower limit value Pmin (NO), the process returns to step S9. In step S9, recording is performed again with a new data recording power Pw that is 0.9 times smaller than the previous data recording power Pw.

  On the other hand, if the verification is good (YES) in step S10, the data recording power Pw does not exceed the upper limit value Pmax even if it is multiplied by 1.1, and a 10% margin is provided on the upper limit side. It can be determined that it has. Based on the above correction sequence, the corrected data recording power Pw is determined as the data recording power Pw for writing actual data in the data area (step S13).

  Such trial writing is performed in the minimum zone (zone 0) on the inner circumference side and the maximum zone (zone n) on the outer circumference side in the optical disc, and linear approximation is performed using the calculated data recording power. Determine the data recording power of the zone. Of course, it is possible to add not only the test writing at these two places but also the test writing in the intermediate zone.

  As described above, in the first embodiment, it can be confirmed that the upper and lower limits have a margin of 10% with respect to the data recording power Pw obtained by trial writing, and there are scratches on the optical disk surface. In addition, even if external noise is superimposed, it can be determined that data recording is performed stably. Although it is desirable to secure the maximum margin, this margin is appropriately set because the characteristics, conditions, setting environment, and the like differ depending on the optical disc and the optical disc apparatus.

Next, the data recording operation of the optical disc apparatus according to the second embodiment of the present invention will be described with reference to the flowchart shown in FIG.
The configuration of the optical disc apparatus of the present embodiment is the same as that of the first embodiment described above, and the operation is different. Normally, the optical disc 2 on which information can be rewritten and recorded (overwritten) may be destroyed when recording with a recording power with a very high value. In the first embodiment described above, a 10% margin is assumed for the upper and lower limits. However, if recording can be performed normally, recording with a lower data recording power is preferable. That is, it may not be preferable to record data with a high data recording power Pw even if the upper limit is not reached. Therefore, in this embodiment, correction of data recording power lower than that in the first embodiment is realized. In the flowchart shown in FIG. 4, the same step numbers are assigned to the same step steps as those in the flowchart shown in FIG. 2, and the detailed description thereof is omitted.

  First, the optical pickup 4 is moved to the test track of the optical disc 2 mounted on the spindle motor 3 (step S1). Test writing is performed on the test track, and a temporary data recording power Pw is set based on the read value (step S2).

  First, trial data is recorded by multiplying the provisional data recording power Pw by 0.9 (step S3).

  Whether or not the recording with the data recording power Pw multiplied by 0.9 is normal is verified to determine whether or not it is good (step S4). If this verification is not good (NO), the data recording power Pw that has become impossible is corrected to a new data recording power Pw multiplied by 1.1 (step S5), and the new data recording power Pw is It is determined whether or not the upper limit value Pmax has been exceeded (step S6). If the upper limit value Pmax is exceeded (NO), error processing is performed (step S7). However, if the upper limit value Pmax is not exceeded (YES), as in step S3, the data recording power Pw is multiplied by 0.9 to be corrected to the new data recording power Pw, and the test writing data is changed to the test track. Is recorded (step S8), and the process returns to step S4.

  Next, in the verification in step S4, when it is determined that the verification of the recording with the data recording power Pw multiplied by 0.9 is good, that is, it has a 10% margin on the lower limit side. (YES) and a 40% margin on the lower limit side. That is, the normal data recording power Pw is multiplied by 0.6 to record the trial writing data (step S21).

  Whether or not the recording with the data recording power Pw multiplied by 0.6 has been normally recorded is verified and determined (step S22). If the verify is satisfactory (YES), the normal data recording power Pw is further corrected to 0.9 times a new data recording power Pw (step S23). It is determined whether or not the new data recording power Pw is lower than a preset value, for example, a lower limit value Pmin (step S24). If the new data recording power Pw is lower than the lower limit value Pmin (YES), the process proceeds to step S7. Error handling. On the other hand, if the new data recording power Pw is not lower than the lower limit value Pmin (NO), the process returns to step S21. In this step S21, recording is performed with the new data recording power Pw set to 0.6 times the data recording power Pw as in the previous case. This is because when the test recording data recorded by multiplying the data recording power Pw having a 10% margin on the lower limit side by 0.6 in step 4 is more than 40 on the lower limit side. % Margin.

  Hereinafter, in step S22, when the verification is good, these steps 21 to S24 are repeated.

  If the verification is not good in step S22 (NO), the temporary data recording power Pw is determined as the data recording power Pw for writing actual data in the data area (step S25).

  With the above sequence, the data recording power Pw having a margin of 10% or more and less than 40% on the lower limit side is determined as the data recording power for writing actual data in the data area.

  Such trial writing is performed in the minimum zone (zone 0) on the inner circumference side and the maximum zone (zone n) on the outer circumference side in the optical disc, and linear approximation is performed using the calculated data recording power. Determine the data recording power of the zone. Of course, it is possible to add not only the test writing at these two places but also the test writing in the intermediate zone.

  According to the second embodiment as described above, by correcting the temporary data recording power determined by trial writing, a recording medium capable of rewriting and recording information with low resistance to high recording power, for example, With respect to the magneto-optical disk, a margin for 10% data recording power is guaranteed on the lower limit side, and data can be recorded stably. Check whether the provisional data recording power determined by trial writing is appropriate, and if it is not appropriate, correct it appropriately to ensure a margin for the data recording power. Information can be recorded.

It is a figure for showing and explaining a conceptual example of an optical disk device of the present invention. 4 is a flowchart for explaining a data recording operation in the optical disc apparatus of the first embodiment. It is a figure which shows the relationship between the data recording power used as a criterion, and an error rate (error rate). It is a flowchart for demonstrating the data recording operation | movement in the optical disk apparatus of a 2nd Example. FIG. 5A is a diagram showing an example of a normal DUTY signal and an amplitude detection signal in a reproduction signal of recorded information, and FIG. 5B is a diagram showing a DUTY at the time of abnormality in the reproduction signal of recorded information. It is a figure which shows the example of a signal and an amplitude detection signal.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Optical disk apparatus, 2 ... Optical disk, 3 ... Spindle motor, 4 ... Loading mechanism, 5 ... Laser beam, 6 ... Optical pick-up, 7 ... Moving mechanism, 8 ... Laser diode (LD), 9 ... Photo detector (PD), 10 DESCRIPTION OF SYMBOLS ... Laser drive circuit, 11 ... Information reproduction circuit, 12 ... Control part, 12a ... Laser control circuit, 12b ... Information processing circuit, 13 ... Host computer.

Claims (8)

In an optical disc apparatus for recording information on an optical disc or reading and reproducing recorded information by a recording or reproducing laser beam emitted from a semiconductor laser,
Before recording information with the recording laser beam, trial writing is performed on the test area of the optical disc, the power of the temporary recording laser beam is set, and the power of the temporary recording laser beam is set to a predetermined value. The trial writing data changed to the upper limit side and the lower limit side within the width is recorded, and whether or not normal recording is possible by checking these readings is detected. An optical disc apparatus comprising: a control unit that corrects a setting of light power so that normal recording is performed within the predetermined width. In the optical disc apparatus,
2. The optical disc apparatus according to claim 1, wherein the upper limit side and the lower limit side within the predetermined width define an upper limit margin and a lower limit margin for the power of the recording laser beam. In an optical disc apparatus for recording information on an optical disc or reading and reproducing recorded information by a recording or reproducing laser beam emitted from a semiconductor laser,
Before recording information with the recording laser beam, perform test writing to the test area of the optical disc, set the power of the temporary recording laser beam,
Within the predetermined width, the first recording for recording the test writing data is performed with the power of the first recording laser light lower than the power of the provisional recording laser light, and this first recording is impossible. If there was, perform the first correction to set the power higher than the lower limit side, and re-record,
When the first recording is normal, the second recording is performed to record the test writing data by the power of the second recording laser beam whose setting is further corrected so as to be sequentially set to the lower limit side. An optical disc apparatus comprising a control unit for setting the power of the temporary recording laser beam when the second recording becomes impossible. 4. The power of the second recording laser beam is a lower limit margin that guarantees normal operation of the power of the first recording laser beam on the lower limit side within the predetermined width. Optical disk device. A semiconductor laser for emitting a recording or reproducing laser beam;
Laser driving means for supplying a reproducing current and a recording current to the semiconductor laser;
The recording information recorded on the recording medium has information reproducing means for reading out and reproducing the recording information by using the reproducing light from the semiconductor laser, and performs test writing in the test area on the recording medium to record data at the time of data recording. In an optical disc apparatus for setting the write power of laser light,
With respect to the data recording power determined by the trial writing, information is recorded by changing the data recording power, and based on the result of reproducing the recorded information, the data recording power determined by the trial writing is normally An optical disc apparatus characterized by checking whether data is recorded and, if not normal, correcting data recording power determined by trial writing. In the optical disc apparatus,
The recording medium is a rewritable recording medium for information, and by recording with a power value lower than the data recording power determined in the trial writing, confirm whether the recording power determined in the trial writing has been normally recorded, 6. The optical disc apparatus according to claim 5, wherein if it is not normal, the data writing power determined by the trial writing is corrected. In a recording / reproducing method of an optical disc in which information is recorded on an optical disc by reading or reproducing laser light emitted from a semiconductor laser, or recorded information is read out and reproduced.
Before recording information with the recording laser beam, a test writing process for performing test writing to a test area of the optical disc;
Set the power of the temporary recording laser beam, record the trial writing data by changing the power of the temporary recording laser beam to the upper limit side and the lower limit side within a predetermined width, and confirm the reading of these data A detection process for detecting whether normal recording is possible or not,
A correction step of correcting the setting of the power of the temporary recording laser beam so that normal recording is performed within the predetermined width when normal recording is impossible in the detection step. An optical disc recording / reproducing method characterized by the above. In a recording / reproducing method of an optical disc in which information is recorded on an optical disc by reading or reproducing laser light emitted from a semiconductor laser, or recorded information is read out and reproduced.
Before recording information with the recording laser beam, performing test writing to the test area of the optical disc and setting the power of the temporary recording laser beam;
Performing a first recording in which test writing data is recorded with a power of the first recording laser light lower than a power of the temporary recording laser light within a predetermined width;
If this first recording is not possible, a step of performing the first correction for setting a higher power than the lower limit side and performing re-recording; and
When the first recording is normal, the step of performing the second recording for recording the data for test writing with the power of the second recording laser light whose setting is further corrected so as to become the lower limit side sequentially. When,
And a step of setting the power of the temporary recording laser beam when the second recording becomes impossible.

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