JP2002298396A - Tracking offset compensating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tracking offset compensating device capable of enhancing tracking characteristics by further enhancing accuracy of tracking offset compared with the conventional device. SOLUTION: Recording and reproduction are performed in the case of a disk T, a recording power margin to indicate relation between a recording power value and the number of errors is detected as to overwrite and cross write and a prescribed recording power value is detected based on the recording power margin in an offset compensation supporting part 70. The number of errors is detected while a tracking offset value at the recording power value is changed, the relation between an offset value and the number of errors is detected and after that, the offset value at which the number of errors is minimum is detected as the optimal tracking offset value. A CPU 80 compensates a tracking error signal by outputting a compensation signal according to the optimal tracking offset value and adding the compensation signal to the tracking error signal from a DPP circuit 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an offset correcting device for correcting an offset in a tracking servo of a recording / reproducing device for recording / reproducing data on a track of a rewritable optical disk such as a magneto-optical disk.

[0002]

2. Description of the Related Art In a recording / reproducing apparatus used for an optical disc such as a magneto-optical disc, a so-called tracking servo off-track in which a light spot of a laser beam irradiated onto a track from an optical head deviates from a center position of a target track. Need to be prevented.

Here, in order to prevent the off-track, conventionally, tracking control is performed in a tracking circuit so that a tracking error signal becomes zero.

That is, the conventional recording / reproducing apparatus B is configured as shown in FIG. FIG. 6 mainly illustrates the relationship between the tracking servo in the conventional recording / reproducing apparatus, and other detailed configurations are omitted.

The optical head 10 irradiates a laser beam to the magneto-optical disk T and detects the reflected light. The light-emitting element for irradiating the laser and an object for condensing the laser emitted from the light-emitting element are provided. It has a lens, an actuator for moving an objective lens in the radial direction and the vertical direction of the magneto-optical disc T, a photodetector for receiving laser light reflected from the magneto-optical disc T, and the like.

That is, the light emitting element of the optical head 10 irradiates a target track of the disk T with laser light via the objective lens. The photo detector is Disk T
And a reflected signal detected by the DPP (Differential Push-P).
(ull method) to the circuit 20.

The DPP circuit 20 generates and outputs a tracking error signal (see FIG. 8) based on the signal sent from the optical head 10. In particular, this DPP circuit 2
0 is for generating a tracking error signal based on the differential push-pull method. Note that this DPP circuit 2
Instead of 0, any device that outputs a tracking error signal, such as one based on a three-spot method or a push-pull method, may be used. The tracking error signal is initially output in a state where a DC offset component is included, based on a control error based on individual differences, for example, a mounting accuracy or a sensitivity difference of the photodetector.

The tracking error signal is A / D-converted by an A / D converter 25 and sent to a DSP 30. In the DSP 30, the tracking servo calculator 32 receiving the tracking error signal converts the DC offset component. Is calculated, that is, a servo amount is calculated so as to make 0 (zero). More specifically, an offset value that makes the tracking error signal 0 (zero) is calculated, and a servo amount corresponding to the calculated offset amount is calculated and output as a servo signal.

The servo signal output from the DSP 30 is D
After being D / A-converted by the / A converter 40, it is sent to the actuator drive control unit 45, and the actuator drive control unit 45
Of the tracking servo. As described above, the tracking offset is corrected. Incidentally, since a signal for focus servo is actually sent from the DSP 30, the focus servo of the optical head 10 of the actuator drive control unit 45 is also performed.

[0010]

However, in the configuration shown in FIG. 7, the tracking offset is corrected only by the tracking error signal as described above.
Off-tracking may occur due to the influence of disturbances in the circuit or the optical system. In other words, the tracking error signal does not indicate off-track, that is, although the laser beam does not deviate from the center of the track,
In practice, the laser light may be off the center of the track.

Therefore, the present invention improves the accuracy of tracking offset correction more than the conventional case,
It is an object of the present invention to provide a tracking offset correction device capable of improving tracking characteristics.

[0012]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a first object of the present invention is to provide a tracking offset correction device for correcting a tracking offset of an optical disk, which comprises: A tracking error signal output unit that outputs a tracking error signal based on the reflected light obtained by irradiating the laser beam to the laser light, and performs recording and reproduction while changing an offset value at a predetermined recording power value, and performs error recording. An optimal offset value detection unit that detects an optimal offset value that is the offset value with the lowest frequency, and the tracking error signal output from the tracking error signal output unit to the offset value detected by the optimal offset value detection unit. And a correction unit for performing correction based on the

According to the tracking offset correction device of the first configuration, the correction unit corrects the tracking error signal output from the tracking error signal output unit based on the optimum offset value detected by the optimum offset value detection unit. Is performed, more favorable tracking offset can be performed, and the influence of disturbance can be reduced as compared with the case where only the tracking error signal is used.

Secondly, a tracking offset correction device for correcting a tracking offset for an optical disk, which outputs a tracking error signal based on reflected light obtained by irradiating a laser beam to the optical disk. A tracking error signal output section,
An optimum offset value detection unit that performs recording and reproduction while changing the offset value at a predetermined recording power value, and detects an optimum offset value that is an offset value with the lowest error frequency; and a correction according to the optimum offset value. A correction signal output unit for outputting a correction signal for correcting the tracking error signal, a tracking error signal output from the tracking error signal output unit, and a correction signal output from the correction signal output unit And an adding unit for adding

According to the tracking offset correction device of the second configuration, the tracking error signal output from the tracking error signal output section is corrected by adding the correction signal output from the correction signal output section by the adding section. Therefore, better tracking servo can be performed, and the influence of disturbance can be reduced as compared with the case where only tracking error signals are used.

Thirdly, there is provided a tracking offset correction device for correcting a tracking offset of an optical disk, which outputs a tracking error signal based on reflected light obtained by irradiating the optical disk with laser light. A tracking error signal output section,
At a predetermined recording power value, recording and reproduction are performed while changing the offset value, and an optimum offset value detecting unit that detects an optimum offset value that is an offset value with the lowest error frequency is output from the tracking error signal output unit. And an offset value calculation unit that calculates a new tracking offset value based on the tracking error signal obtained and the offset value detected by the optimum offset value detection unit.

Fourthly, in the first, second or third configuration, the optimum offset value detecting section records a signal on the optical disc for each of a plurality of recording power values, By performing signal reproduction and calculating an error frequency, a second detection is performed to detect a recording power margin indicating the relationship between the recording power value and the error frequency and the relationship between the recording power value and the error frequency in the cross write. A recording power detection unit for detecting a predetermined recording power value in a detected recording power margin, wherein the recording power detection unit detects at least a recording power value at a predetermined error frequency; Performs signal recording and reproduction on the optical disk while changing the tracking offset value at the recording power value detected by the detection unit. Calculating a frequency of the error, thereby detecting a relationship between the tracking offset value and the frequency of the error, based on the relationship between the tracking offset value detected by the second detection unit and the frequency of the error. And a third detection unit that detects an offset value with the lowest error frequency as an optimum offset value.

According to the tracking offset correction apparatus of the fourth configuration, in each of the normal write and the cross write, the recording power margin is detected, the recording power value is detected, and the tracking power is detected at the recording power value. By recording and reproducing signals on the optical disk while changing the offset value and calculating the frequency of the error, after detecting the relationship between the tracking offset value and the frequency of the error, the frequency of the error becomes the lowest. Since the optimum offset value is set as the optimum offset value, a good optimum offset value can be detected, and good correction of the tracking error signal can be performed.

Fifth, in the fourth configuration, the recording power detector detects a recording power value at which the error frequency becomes a predetermined value based on a relationship between the recording power value and the error frequency. One recording power value between a certain first recording power value and a second recording power value that is a recording power value at which the error frequency becomes a predetermined value based on the relationship between the recording power value and the error frequency in the cross write. Alternatively, both recording power values are detected.

Sixthly, in the fourth or fifth configuration, the recording power detection unit performs recording in which the error frequency becomes a predetermined value based on the relationship between the recording power value and the error frequency. A first recording power value that is a power value, a second recording power value that is a recording power value at which the error frequency becomes a predetermined value based on a relationship between the recording power value and the error frequency in the cross write, Detecting a first recording power value and a third recording power value that is an average value of the second recording power value, and the second detecting unit detects the first recording power value and the second recording power value;
For each of the recording power value and the third recording power value, the relationship between the tracking offset value and the frequency of the error is detected, and the third detection unit determines the tracking offset value based on the first recording power value. The average of the error frequency, the error frequency based on the second recording power value, and the error frequency based on the third recording power value is calculated to calculate an average error frequency. It is characterized in that an optimum offset value is set.

Seventh, in the fourth or fifth configuration, the recording power detection unit performs recording in which the error frequency becomes a predetermined value based on the relationship between the recording power value and the error frequency. A first recording power value, which is a power value, and a second recording power value, which is a recording power value at which the error frequency becomes a predetermined value, are detected based on the relationship between the recording power value and the error frequency in cross writing. The second detector detects a relationship between a tracking offset value and an error frequency for each of the first recording power value and the second recording power value. In the offset value, the average error frequency is calculated by averaging the error frequency based on the first recording power value and the error frequency based on the second recording power value. Kicking, characterized in that the optimum offset value offset.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a recording / reproducing apparatus A according to the present invention includes: an optical head 10;
A DPP circuit 20, an A / D converter 25, an adder (addition unit, correction unit) 27, and a DSP (Digital Sig)
nal Processor) 30 and D / A converter 4
0, an actuator drive control unit 45, a D / A converter 50, a laser drive control unit 55, a magnetic head drive control unit 60, a spindle motor 68, and an offset correction support unit 70.

Here, the optical head 10 irradiates a laser beam to a magneto-optical disk T (hereinafter simply referred to as a “disk T”) and detects the reflected light. It has an objective lens for condensing the laser emitted from the light emitting element, an actuator for moving the objective lens in the radial and vertical directions of the magneto-optical disk T, a photodetector for receiving laser light reflected from the disk T, and the like. ing.

The DPP circuit 20 generates and outputs a tracking error signal based on the signal sent from the optical head 10. In particular, the DPP circuit 20 generates a tracking error signal based on a differential push-pull method. Instead of the DPP circuit 20, a circuit based on a three-spot method or a push-pull method may be used. This DPP circuit 20 functions as the tracking error signal output section.

The DSP 30 has a tracking servo calculation section 32 for performing various controls of each section in the recording / reproducing apparatus A, a laser power control section 34, a magnetic head control section 36, and the like.

Here, the tracking servo calculator 32
Calculates a servo amount such that the DC offset component included in the tracking error signal is set to 0 (zero). Specifically, it calculates an offset value that makes the DC offset component 0 (zero), calculates a servo amount corresponding to the calculated offset amount, and outputs it as a servo signal.

The laser power control section 34 is for controlling the power of the laser light emitted from the optical head 10, and outputs a control signal for controlling the laser power. Further, the magnetic head control unit 36 outputs a control signal for controlling driving of the magnetic head 65.

Further, the actuator drive control unit 45 includes:
The tracking servo of the optical head 10 is performed based on the servo signal sent from the DSP 30. Note that the actuator drive control unit 45 actually also performs focus servo.

The laser drive control unit 55 includes a DSP 3
The laser output amount output from the light emitting element of the optical head 10 is controlled based on the control signal from 0. Further, the magnetic head drive control unit 60 controls the drive of the magnetic head 65 based on a control signal from the DSP 30.

Further, the offset correction support unit 70 is provided in FIG.
As shown in the figure, an RF amplifier circuit 72 and an equalizer 74
, Read channel 76, decoder 78, CPU 8
0.

Here, the RF amplifier circuit 72 detects and amplifies an RF signal (magneto-optical signal) from a signal received by a photodetector in the optical head 10. Further, the equalizer 74 removes the waveform interference of the RF signal from the RF amplifier circuit 72. further,
The read channel 76 performs processing such as converting an RF signal as an analog signal into a digital signal. Further, the decoder 78 performs a reproduction process of a signal from the read channel 76 and outputs a reproduction signal.

The CPU 80 performs various processes for correcting the offset based on the reproduction signal and the like from the decoder 78. In particular, the recording power margin (Write Power) is determined by the recording power characteristics of overwrite and cross write. Margin)
From the calculated recording power margin, three predetermined recording power (Write Power) values are detected, and then, for each of the detected three recording power values, the BER (Bit) is changed while changing the offset value.
Error Rate), the relationship between the offset value and the BER is calculated, and various processes for calculating the optimum tracking offset value are performed. In this embodiment, in order to detect a BER, for example, a PI error (PI ERROR (PI: Inne)
r-code Parity)). Also, instead of a PI error, a PO error (PO error
ERROR (PO: Outer-code Pari
ty)) may be used. A detailed description will be given later.

In FIG. 1, the offset correction support unit 70 and each unit controlled based on the CPU 80 are:
It functions as the tracking offset correction device.

Next, the operation of the recording / reproducing apparatus A having the above configuration will be described with reference to FIGS.

First, when the disk is mounted on the recording / reproducing apparatus A and the recording / reproducing apparatus A is started, the optical head 10 is driven to irradiate the disk T with a laser beam (S10). Is performed (S11). In step S11, first, a tracking offset is corrected in the same manner as in the related art.

The correction of the tracking offset is performed for the land and the groove. That is, in the optical head 10, the light emitting element irradiates the target track of the disk T with the laser beam via the objective lens, and the photodetector detects the reflected signal reflected from the disk T,
The detected reflection signal is sent to the DPP circuit 20.

The DPP circuit 20 generates and outputs a tracking error signal based on the signal sent from the optical head 10. Note that, at this stage, the tracking error signal is a control error based on individual differences, for example,
Based on the mounting accuracy and the sensitivity difference of the photodetector, the output is performed in a state where the electric DC offset amount is included.

The tracking error signal output from the DPP circuit 20 is A / D converted by an A / D converter 25 and then sent to a DSP 30.
The tracking servo calculator 32 receiving the tracking error signal sets the DC offset amount to 0 (zero).
Is calculated. Specifically, an offset value that makes the DC offset amount zero is calculated,
A servo amount corresponding to the calculated offset amount is calculated and output as a servo signal.

The servo signal output from the DSP 30 is D
After being D / A-converted by the / A converter 40, it is sent to the actuator drive control unit 45, and the actuator drive control unit 45
Of the tracking servo. As described above, the tracking offset is corrected. In practice, since a signal for focus servo is also transmitted from the DSP 30, the actuator drive control unit 45 also performs focus servo of the optical head 10.

Next, a seek to the groove is performed (S
12) Then, the offset of this groove is corrected (S13).

In step S13, a process as shown in FIG. 3 is performed. That is, first, a recording power margin is detected (S20). This is the recording power,
That is, the relationship between the recording power and the PI error is detected for each of the normal light and the cross light while changing the laser power of the light emitting element in the optical head 10.

That is, while changing the recording power by the laser power control unit 34,
Recording power value (hereinafter referred to as “recording power value”) and PI
In addition to calculating the relationship with the error, the relationship between the recording power value in the cross write and the PI error is calculated. That is, at a certain recording power, a signal is recorded on the groove and land of the disk T, and the signal recorded on the disk T is overwritten. At this time,
When the recording power is high, adjacent tracks are cross-written. The recording in this case is performed in the groove. Thereafter, reproduction is performed to detect the number of errors, and the number of errors in normal operation and the number of errors in cross writing are detected. In the case of normal writing, the recorded signal is reproduced, and in the case of cross writing, the signal recorded on the track on which the signal is recorded, that is, the signal recorded on the land adjacent to the groove is reproduced.

Thereafter, the recording power is changed by a predetermined amount,
By repeating the same processing, the relationship between the recording power and the PI error is detected for each of the normal write and the cross write.

When recording data, data to be recorded is held in the CPU 80, and recording is performed by controlling the magnetic head controller 36 and the laser power controller 34 under the control of the CPU 80. On the other hand, when reproducing data, the magnetic head control unit 36 and the laser power control unit 34 are controlled under the control of the CPU 80 to perform reproduction.
80 is input. The calculation of the PI error is performed by the CPU 80. In other words, the detection of the recording power margin
This is performed by the CPU 80 as the first detection unit.

FIG. 5 shows a specific example of the detected recording power margin. A curve L1 indicates a normal recording power margin, and a curve L2 indicates a recording power margin in the case of cross writing. .

Next, in the recording power margin detected in step S20, the recording power values at three predetermined points are detected (S21). That is, the recording power value when the PI error is 20 lines (Line) in the case of overwriting (this is referred to as the “first recording power value”), and the PI error is 20 lines (Line) in the case of cross writing The recording power value in the case of
Recording power value ”), the first recording power value and the second
An average recording power value of the recording power values (this is referred to as a “third recording power value”) is detected. In the example of FIG. 5, the recording power value a1 is the first recording power value, the recording power value a2 is the second recording power value, and the recording power value a3 is the third recording power value. The detection of each recording power value is performed by the CPU 80 as the recording power detection unit.
It is performed by

As described above, the first recording power value and the second recording power value
When the recording power value and the third recording power value are detected, a PI error is detected while changing the offset value at each recording power value (S22). This step S
The operation of 22 is performed as shown in FIG.

First, the recording power is set (S30).
That is, first, the first recording power value is set by the laser power control unit 34.

Then, the offset value is set to the initial value (S31). The initial value is specifically set to 0 (zero). The value of the offset value is sent from the CPU 80 to the tracking servo calculation unit 32, and the tracking servo calculation unit 32 calculates a servo amount based on the offset value, and outputs a servo signal having information on the servo amount. . As a result, the optical head 10 is controlled so that the offset value is zero.

Then, recording and reproduction are performed on the disk T to detect a PI error (S32). That is, the number of errors is detected. The recording in this case is performed on the groove.

Then, it is determined whether or not the number of errors exceeds a predetermined value (for example, 100) (S33).
If not, change the offset value by a predetermined amount,
The PI error is detected again (S32). That is, if the number of detected errors does not exceed the predetermined range, the process of detecting the number of errors by changing the offset value is repeated. That is, the processes of steps S32, S33, and S34 are repeated. The offset value newly set in step S34 is sent from the CPU 80 to the tracking servo calculator 34.

In practice, the offset value is changed from 0 to +
The number of errors is detected by changing the number in the (plus) direction, and when the number of errors exceeds a predetermined value, this time from 0 to −
The number of errors is detected by changing in the (minus) direction, and when the number of errors exceeds a predetermined value, the process proceeds from step S33 to step S35. As described above, the relationship between the tracking offset value and the PI error is detected.
The detection of this relationship is performed by the CPU 80 as the second detection unit.
It is performed by

Then, in step S35, it is determined whether or not there is another recording power value for which an error is to be detected. If there is, the process returns to step S30 to set the recording power again. The processing is also performed for other recording powers. That is, if the processing for the first recording power value has been completed, the second recording power value is set. Then, the processing of steps S31 to S33 is repeated, and if the processing for the second recording power value has been completed, the third recording power value is set, and
Steps S31 to S33 are repeated.

FIG. 6 shows an example of the result of performing the processing in step S22. In FIG.
e Power Point ”corresponds to the first recording power, and is referred to as“ Cross Write Power P ”.
oint ”corresponds to the second recording power, and“ Cen ”
“ter Write Power Point” corresponds to the third recording power.

As described above, when the relationship between the offset value and the PI error at each recording power value is obtained, the optimum tracking offset value is calculated (S23). That is, from the relation obtained in step S22, the number of errors (that is, PI ErrorLine Number)
Find the offset value when is the lowest. In particular,
For each offset value, the average value of the number of errors for three recording powers is calculated, and the offset value when the average value is the smallest is set as the optimum tracking offset value. This optimum tracking offset value is
Is calculated by That is, in this case, the CPU 80
This corresponds to the above-described optimum offset value detection unit and the third detection unit.
This optimum tracking offset value corresponds to the above-described optimum offset value.

When the optimum tracking offset value has been calculated in step S23, the CPU 80 inputs this optimum tracking offset value to the adder 27. In this case, the tracking error signal is input from the A / D converter 25 to the adder 27 in the form of a voltage value.
The CPU 80 converts the information of the offset value into a voltage value, and inputs the voltage value to the adder 27. That is, the CPU 80
It also functions as the correction signal output unit.

Then, the tracking error signal sent from the A / D converter 25 is corrected by the optimum tracking offset value, and the corrected tracking error signal is input to the DSP 30.

Then, the DSP 30 calculates the servo amount in accordance with the corrected tracking error signal and corrects the tracking offset, so that not only a normal tracking error signal but also a signal is obtained by recording and reproducing. Since the optimum tracking offset value is also taken into consideration, more favorable tracking servo can be performed.

The processing shown in step S13 is as follows.
The same applies to lands. That is, step S1
After step 3, seek is performed on the land (S14), and the same processing as in step S13 is performed on the land (S1).
5). In this case, the signal is recorded on the land. That is, step S20 or step S20
The recording of the signal at 32 is performed on the land.

As described above, the optimum tracking offset can be corrected for each of the groove and the land. After that, processes such as recording and reproduction of the recording data are performed.

In the above description, when calculating the optimum tracking offset value, the relationship between the offset value and the PI error for each of the first recording power value, the second recording power value, and the third recording power value is determined. Detect
Although the description has been made assuming that the offset value when the average of the number of errors is the lowest is obtained, the relationship between the offset value of the recording power value of 1 or 2 in the above three recording power values and the PI error is detected, and the optimum tracking offset is obtained. The value may be calculated. In this case, for example, when only one recording power value is used, the relationship between the offset value and the PI error at that recording power value is detected,
The offset value when the number of errors is the lowest is set as the optimum tracking offset value. When two recording power values are used, the relationship between the offset value and the PI error is detected for the two recording power values, and the offset value when the average of the number of errors is the smallest is determined.

In the above description, the signal from the CPU 80 is described as being added to the tracking error signal output from the A / D converter 25.
The information of the optimum tracking offset value obtained in U80 is input to the tracking servo calculator 32, and the tracking servo calculator 32 corrects the offset value obtained from the tracking error signal based on the optimum tracking offset value. It may be. In that case, the tracking servo calculation unit 32 corresponds to the offset value calculation unit.

[0063]

According to the tracking offset correction device according to the present invention, the correction unit corrects the tracking error signal output from the tracking error signal output unit based on the optimum offset value detected by the optimum offset value detection unit. Therefore, better tracking servo can be performed, and the influence of disturbance can be reduced as compared with the case where only tracking error signals are used.

According to the tracking offset correction apparatus of the present invention, the tracking error signal output from the tracking error signal output section is corrected by adding the correction signal output from the correction signal output section by the adder. Therefore, better tracking servo can be performed, and the influence of disturbance can be reduced as compared with the case where only tracking error signals are used.

In particular, when the apparatus has the first detecting section, the recording power detecting section, the second detecting section, and the third detecting section, the recording power margin is detected in each of the normal write and the cross write. Then, the recording power value is detected, the signal is recorded and reproduced on and from the optical disk while changing the tracking offset value at the recording power value, and the frequency of the error is calculated. After detecting its relationship to the frequency of
Since the offset value with the lowest error frequency is the optimal offset value, a good optimal offset value can be detected,
Good correction of the tracking error signal can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of the recording / reproducing apparatus according to the embodiment of the present invention.

FIG. 3 is a flowchart showing an operation of the recording / reproducing apparatus according to the embodiment of the present invention.

FIG. 4 is a flowchart showing an operation of the recording / reproducing apparatus according to the embodiment of the present invention.

FIG. 5 is an explanatory diagram showing an example of a recording power margin.

FIG. 6 is an explanatory diagram showing an example of a relationship between an offset value and a PI error at each recording power value.

FIG. 7 is a block diagram showing a configuration of a conventional recording / reproducing apparatus.

FIG. 8 is an explanatory diagram showing an example of a tracking error signal.

[Explanation of symbols]

 A recording / reproducing device 10 optical head 20 DPP circuit 25 A / D converter 27 adder 30 DSP 32 tracking servo calculation unit 34 laser power control unit 36 magnetic head control unit 40, 50 D / A converter 45 actuator drive control unit 55 Laser drive control unit 60 Magnetic head drive control unit 65 Magnetic head 70 Offset correction support unit 80 CPU

Continued on the front page (72) Inventor Seiichiro Takahashi 2-5-5 Keihanhondori, Moriguchi-shi, Osaka F-term in Sanyo Electric Co., Ltd. 5D090 AA01 BB04 CC12 DD03 FF02 JJ20 5D118 AA14 BA01 BB02 BF07 CA13 CD03 CD08 CD11

Claims (7)

[Claims] 1. A tracking error correction device for correcting a tracking offset of an optical disk, the tracking error signal output unit outputting a tracking error signal based on reflected light obtained by irradiating the optical disk with a laser beam. An optimum offset value detection unit that performs recording and reproduction while changing the offset value at a predetermined recording power value, and detects an optimum offset value that is an offset value with the lowest error frequency; and the tracking error signal output unit. A correction unit for correcting the tracking error signal output from the control unit based on the offset value detected by the optimum offset value detection unit. 2. A tracking offset correction device for correcting a tracking offset of an optical disk, the tracking error signal output unit outputting a tracking error signal based on reflected light obtained by irradiating the optical disk with laser light. An optimum offset value detection unit that performs recording and reproduction while changing the offset value at a predetermined recording power value, and detects an optimum offset value that is an offset value with the lowest error frequency; A correction signal output section for outputting a correction signal for correcting the tracking error signal, a tracking error signal output from the tracking error signal output section, and a correction signal output section output from the correction signal output section. An adder for adding the correction signal. Tracking offset correction apparatus according to claim. 3. A tracking offset correction device for correcting a tracking offset of an optical disk, the tracking error signal output unit outputting a tracking error signal based on reflected light obtained by irradiating the optical disk with laser light. An optimum offset value detection unit that performs recording and reproduction while changing the offset value at a predetermined recording power value, and detects an optimum offset value that is an offset value with the lowest error frequency; and the tracking error signal output unit. A tracking error correction device that calculates a new tracking offset value based on the tracking error signal output from the controller and the offset value detected by the optimum offset value detecting unit. . 4. The optimum offset value detecting section records a signal on an optical disc for each of a plurality of recording power values, reproduces the signal, and calculates an error frequency to thereby determine a recording power. A first detecting unit for detecting a recording power margin indicating a relationship between a recording power value and an error frequency in a cross write, and a predetermined recording power value in the detected recording power margin. A recording power detector that detects a recording power value at least at a predetermined error frequency; and a recording power value detected by the recording power detector.
A second detector for recording and reproducing signals on and from the optical disc while changing the tracking offset value and calculating an error frequency, thereby detecting a relationship between the tracking offset value and the error frequency; A third detection unit that detects, as an optimum offset value, an offset value with the lowest error frequency based on a relationship between the tracking offset value detected by the second detection unit and the error frequency. Claim 1 or 2
Or the tracking offset correction device according to 3. 5. A recording power detecting section, comprising: a first recording power value that is a recording power value at which an error frequency becomes a predetermined value, based on a relationship between the recording power value and an error frequency; Detecting, based on a relationship between the power value and the error frequency, one or both of the recording power values of the second recording power value which is a recording power value at which the error frequency becomes a predetermined value; The tracking offset correction device according to claim 4, wherein 6. A recording power detecting section, comprising: a first recording power value that is a recording power value at which an error frequency becomes a predetermined value, based on a relationship between the recording power value and an error frequency; Based on the relationship between the power value and the frequency of error, a second recording power value that is a recording power value at which the frequency of error becomes a predetermined value, and an average value of the first recording power value and the second recording power value. A third recording power value, and the second detection unit calculates a tracking offset value and an error frequency for each of the first recording power value, the second recording power value, and the third recording power value. The third detector detects, at each tracking offset value, an error frequency based on the first recording power value, an error frequency based on the second recording power value, 6. The tracking offset correction according to claim 4, wherein an average error frequency is calculated by averaging an error frequency based on the recording power value, and an offset value at the average error frequency is set as an optimum offset value. apparatus. 7. A recording power detecting section, comprising: a first recording power value that is a recording power value at which an error frequency becomes a predetermined value, based on a relationship between the recording power value and an error frequency; A second recording power value which is a recording power value at which the error frequency becomes a predetermined value, based on a relationship between the power value and the frequency of the error, wherein the second detecting unit detects the first recording power value And a relationship between the tracking offset value and the error frequency for each of the second recording power value, and the third detection unit detects the error frequency based on the first recording power value at each tracking offset value. And an error frequency based on the second recording power value, to calculate an average error frequency, and determine an offset value at the average error frequency as an optimum offset value. 6. The method according to claim 4, wherein
2. The tracking offset correction device according to 1.