JP2000173060A - Optical disc apparatus and data reproducing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disc apparatus and a reproducing method assuring excellent reproducing signal quality which allow simultaneously obtaining the optimum parameter of a header area and head area without increase of the learning time. SOLUTION: An optical disc information reproducing apparatus is provided with a jitter value measuring means 110 and an error measuring means 111. The readability of header area and data area can be improved without increase of the learning time by simultaneously optimizing the parameter using the number of header errors for the header area and jitter value for the data area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device which is connected to a computer or the like and records / reproduces data using light.

[0002]

2. Description of the Related Art In recent years, demand for large-capacity optical disks has been increasing with the progress of multimedia in society. DVD-ROM for reproducing CD-ROM with greatly improved recording capacity
Drive devices have been developed. Also rewritable, D
VD-RAM is receiving attention. Since DVDs have a basic concept of playback compatibility, DVD-
With the spread of RAM, the need for DVD-RAM disc playback in DVD-ROM drive devices is also increasing.

FIG. 3 is a diagram showing a DVD-RAM disk format. As shown in FIG. 3, the DVD-RAM disk has a header at the head of each sector unlike a conventional ROM disk, and a data portion follows the header. The disk is divided into zones, and the innermost zone 0
The number of sectors per track is 17, and 1
Each time the zone increases, the number of sectors per track also increases by one, and the outermost zone 23 has 40 sectors per track.

[0004] The header portion is necessary because the DVD-RAM disk is recordable. If the header portion cannot be reproduced correctly during reproduction of the RAM disk, the physical address being reproduced at present cannot be known, and the data portion cannot be reproduced correctly. .
This header contains an ID to improve read reliability.
, And PID1,
2 and PIDs 3 and 4 are arranged offset to the left and right. PID1 and PID2 are the same physical address, PID3
And PID4 are the same physical address, and the position of the data part following the header part can be specified from the relationship between these four physical addresses. Further, ID error detection information called IED is added to each PID, and it can be confirmed whether each address can be read correctly.

As described above, DVD-RAM discs are
The point that a conventional header has a header at the beginning of each sector
Different from VD-ROM disk, but detects the header part,
If the PID is read and the physical address is specified, the format of the data portion is the same as that of the ROM, so that the data can be read by performing the same processing as in the ROM disk reproduction.

FIG. 4 shows the configuration of a conventional optical disk device. The procedure for reproducing a DVD-RAM disc will be described with reference to FIG. A conventional DVD-RAM disc reproducing apparatus emits a laser beam from a light emitting element, irradiates the optical disc 502 via an optical system, and receives a laser beam from the optical disc 502 with a light receiving element 501. A signal detector 503 for detecting an RF signal output from the PUM 501; and a waveform equalizer 504 for performing a waveform equalization process on the RF signal.
And the slice / P for binarizing the RF signal equivalent to this waveform
LL section 505, demodulation / error correction section 506 for executing demodulation and error correction on the binary data, jitter measuring means 510 for monitoring and integrating the jitter voltage of the binary data, and jitter integration section 510. A control unit 509 that outputs a servo parameter signal based on the integrated jitter signal, a servo control unit 507 that performs servo control based on the servo parameter signal and the RF signal, and a drive unit 508 that drives the PUM 501 based on the servo control. It is a configuration provided with:

Next, an information reproducing operation of the conventional optical disk device based on the above configuration will be described. PUM501
The optical disk 502 is irradiated with the laser output from the optical disk 502, the return light is received by a light receiving element on the PUM 501, and the converted signal is subjected to IV conversion. An RF signal required for signal reproduction by the signal detection unit 503 and a focus error signal required for servo. , A tracking error signal, and the like, and a header section processing for detecting a header section unique to the DVD-RAM and processing the header section signal so that signal processing can be performed similarly to the RF signal.
The RF signal or R generated by the signal detection unit 503 described above.
The header signal converted into the F signal is input to the waveform equalization unit 504, and is subjected to appropriate waveform equalization. The aforementioned waveform equalizer 504
The RF signal waveform-equivalent to
5 and becomes binary data in the slice / PLL unit 505, and a clock is extracted from the binary data. The data generated by the slice / PLL unit 505 is input to the demodulation / error correction unit 506, where it is demodulated and error-corrected, and is input to a subsequent interface circuit (not shown).

In the demodulation / error correction unit 506, error detection is performed for each PID in the header portion.
The physical address is calculated from the PID having no error. Since the data in the data portion is 2 Kbytes in each sector, 16 sectors are stored in 1 sector.
Error correction is performed every 32 Kbytes as an ECC block. The focus error signal and the tracking error signal detected by the signal detection unit 503 are input to the servo unit 507, and generate control signals for performing focus position control, tracking position control, and optical head feed control. The control signal generated by the servo unit 507 is input to the drive unit 508, and the focus of the PUM 501 is
A drive signal for driving the tracking actuator and a signal for driving the spindle motor and the sled are generated. RF generated by slice / PLL unit 505
The binarized data of the signal is input to the jitter measuring unit 510, and the jitter measuring unit 510 has a function of monitoring and integrating the jitter voltage of the binarized data generated by the slice / PLL unit 505. The jitter voltage is a P value generated from the binarized data based on the binarized data.
This is obtained by converting the temporal fluctuation with respect to the clock after LL into a voltage, and the smaller the value, the better the reproduction signal quality.

Next, the reason why it is necessary to learn servo parameters and the like in a DVD will be described. DVDs have a high density compared to CDs, so that the quality of reproduced signals is significantly deteriorated. Therefore,
In DVD, parameter learning is generally performed at the time of startup to improve the quality of a reproduced signal. The parameters here include servo-related parameters such as a focus position and a tracking position of the optical head, and signal processing parameters such as a frequency as a waveform equivalent coefficient for performing waveform shaping and a boost amount.

Here, the focus position learning will be described in detail. The focus position can be adjusted by adding an offset to the servo loop of the focus system. Conventionally, there is a method using a jitter voltage as a teacher signal for learning. It can be said that the smaller the value of the jitter voltage is, the better the reproduction signal quality is. FIG. 5 is a diagram showing the relationship between the focus position and the jitter. As can be seen from FIG. 5A, by changing the focus position and using the jitter voltage as the teacher signal,
The minimum point is obtained, and that point becomes the optimum focus position.

[0011]

However, the above-mentioned conventional configuration has the following problems at the time of reproducing a DVD-RAM disc. First, in this case, in learning at one focus position, it is necessary to use an average value for one round of the disk in consideration of jitter fluctuation. For example, DV
Assuming that the learning is performed at the innermost circumference of the D-ROM standard speed, it takes a time of 24 ms for one round of the disc (calculated from the DVD single-layer disc at 1 × speed and the innermost circumference of 1433 rpm). Although it is better to increase the number of sample points in order to increase the learning accuracy, the total learning time becomes longer.

Next, a DVD-RAM disc has a header section and a data section, which are physically different in disc format. Conventionally, parameter optimization is performed in the data section, and the result is compared in both the header section and the data section. I was using it. FIG. 5B shows the result of learning of the focus position of the header portion and the data portion of the DVD-RAM. As can be seen from FIG. 5B, the optimum focus position is different between the header part and the data part. In other words, there is a problem that the error rate of the header part becomes high with the parameter of the data part best in the DVD-RAM disk.

Therefore, a method of separately learning parameters in the data section and the header section can be considered. However, in the conventional parameter learning, only the jitter voltage is used as a teacher signal, so that learning can be performed only sequentially. ,
There is a problem that a learning time twice as long as the learning of the data part is required, such as the learning of the header part after the learning of the data part.

The present invention solves the above-mentioned conventional problems. By simultaneously optimizing the parameter learning of the header section and the data section based on different teacher signals, the data section can be extended without extending the parameter learning time. It is another object of the present invention to provide an optical disk apparatus and a reproducing method which can simultaneously obtain an optimum parameter of a header portion and have excellent reproduction signal quality.

[0015]

In order to achieve this object, an optical disk apparatus and a reproducing method according to the present invention utilize the number of header errors as a learning teacher signal for a header portion and a jitter value as a learning teacher signal for a data portion. It is characterized by the following.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is to correct a control signal for an optical pickup by starting a read operation for reading an information signal from an optical disc on which information is recorded by an optical pickup. An optical disc device for performing a read operation of: a jitter measuring means for outputting a jitter integrated signal based on an information signal; detecting an error included in the information signal and adding an error number of the information signal to generate an error addition signal. An error number measuring means for outputting, and a control operation means for generating a learning teacher signal for correcting a control signal for controlling the operation of the optical pickup based on the jitter integration signal and the error addition signal. Performing a read operation on the optical disk after correcting the control signal based on the signal,
The quality of the reproduced signal can be improved without increasing the learning time at the time of starting the reading operation.

According to a second aspect of the present invention, the sector of the information recorded on the optical disk has a header portion and a data portion, and the learning teacher has the best reading characteristics for the header portion and the data portion. The signal is generated by the control operation means, and the signal is generated without increasing the parameter learning time.
This has the effect that an optical disk device capable of improving the readability of a VD-RAM disk can be configured.

According to a third aspect of the present invention, at the time of starting a reading operation for reading an information signal from an optical disk on which information is recorded by an optical pickup, a control signal for the optical pickup is corrected to execute the reading operation of the optical disk. A data integration method for integrating a jitter component included in an information signal, an error addition step for detecting an error included in the information signal and adding the number of errors of the information signal, and a jitter integration signal step. A learning signal generating step of generating a learning teacher signal for correcting a control signal for controlling the reading operation of the optical pickup by the error adding step; and executing the learning signal generating step at the time of starting the reading operation. Increase readability of DVD-RAM discs without increasing learning time Data reproducing method which enables to above has the effect that can be constructed.

According to a fourth aspect of the present invention, the sector of the information recorded on the optical disk has a header section and a data section, and the learning signal is adjusted so that the read characteristics for the header section and the data section are optimized. In this step, the parameters of the header section and the data section can be optimized at the same time, so that the DVD-
This has the effect that a data reproduction method that can improve the readability of the RAM disk can be configured.

(Embodiment 1) An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a configuration diagram of an optical disk device according to Embodiment 1 of the present invention. FIG. 1 shows a configuration diagram of a DVD-RAM disc reproducing device as an example of the optical disc device of FIG. The procedure for reproducing a DVD-RAM disc according to the present invention will be described with reference to FIG.

FIG. 1 shows a DVD-ROM according to this embodiment.
As in the conventional apparatus of FIG. 4, the RAM disk reproducing apparatus includes a PUM 101, a signal detecting unit 103, a waveform equalizing unit 104, a slice / PLL unit 105, a demodulation / error correction unit 106, a jitter measuring unit 110 and the control unit 10
9 and a servo unit 107 and a drive unit 108 in common. In addition to this configuration, the demodulation / error correction unit 106 adds and measures the number of errors for which error correction is performed, and outputs an error addition signal to the control unit. Error number measuring means 1 output at 109
11 is provided. The control unit 109 generates a correction parameter signal based on the error addition signal from the error number measurement unit 111 and the jitter integration signal from the error number measurement unit 111, and uses the correction parameter signal to generate the correction parameter signal.
07 is controlled.

Next, an information reproducing operation of the apparatus according to the present embodiment based on the above configuration will be described. The laser beam output from the PUM 101 is applied to the optical disc 102, the return light is received by the light receiving element on the PUM 101, subjected to IV conversion, and the signal detection unit 103 performs an RF signal required for signal reproduction and a focus error required for servo. A signal, a tracking error signal, and the like are generated, and a header process specific to the DVD-RAM is detected and the header signal is processed so that the signal process can be performed similarly to the RF signal. The RF signal generated by the signal detection unit 103 or the header signal converted into an RF signal is input to the waveform equalization unit 104 and subjected to appropriate waveform equalization. The RF signal whose waveform has been equalized by the waveform equalizing unit 104 is input to a slice / PLL unit 105, and becomes binary data in the slice / PLL unit 105, and a clock is extracted from the binary data.

The data generated by the slice / PLL unit 105 is input to a demodulation / error correction unit 106, where it is demodulated and error-corrected, and is input to a subsequent interface circuit (not shown). In the demodulation / error correction section 106, an error is detected for each PID in the header section, a physical address is calculated from the PID having no error, and since the data in the data section is 2 Kbytes in each sector, 16 sectors are regarded as one ECC block. Error correction is performed every 32 Kbytes.

The focus error signal and the tracking error signal detected by the signal detection unit 103 are input to a servo unit 107 to generate control signals for performing focus position control, tracking position control, and optical head feed control. The control signal generated by the servo unit 107 is input to the drive unit 108, and the focus of the PUM 101
A drive signal for driving the tracking actuator and a drive signal for driving the spindle motor and the sled are generated. The jitter measuring means 110 calculates the slice / P
It has a function of monitoring and integrating the jitter voltage generated by the LL unit 105. The jitter voltage is obtained by converting a temporal fluctuation with respect to a clock after PLL generated from the binarized data based on the binarized data into a voltage,
It can be said that the smaller the value is, the better the reproduction signal quality is.

The error number measuring means 111 has a function of monitoring and adding the number of header errors detected by the demodulation / error correction section 106. The control unit 109 receives the jitter integration signal obtained by integrating the jitter signal by the jitter measurement unit 110 and the error addition signal obtained by adding the number of errors in the header unit by the error number measurement unit 111, A correction parameter signal is generated based on the jitter integration signal and the error addition signal, and output to the servo unit 107 and the waveform detection unit 103. The servo unit 107 corrects a control signal for performing focus position control, tracking position control, and optical head feed control based on the input correction parameter signal, and outputs the corrected control signal to the driving unit 108. I do.

Next, the outline of the simultaneous learning of the header part and the data part parameter will be described. The simultaneous learning of the header part and the data part parameter in this case is performed by the control unit 109 under the control of the CPU.
Can be configured and executed automatically. In addition, if the control unit 109 is configured by a control circuit, it can be realized without using a CPU.

The simultaneous focus position parameter learning of the header portion and the data portion by the control unit 109 is, for example, as follows. FIG. 2 shows an example of a flowchart of the parameter simultaneous learning. By performing a series of processes shown in FIGS. 2A, 2B, and 2C, the number of errors and the jitter value for one parameter for each of the header portion and the data portion are simultaneously obtained. By repeating such a series of processing, it is possible to simultaneously obtain the optimum point of the parameters of the header section and the data section (the focus position operating at the minimum point of the jitter voltage of both sections) as shown in FIG. . FIG.
A detailed description will be given of the simultaneous learning of the header position and the data portion focus position parameters with reference to FIG.

In the figure, # 1 to # 4 indicate steps. In step # 1, it is determined whether the currently reproduced part is a data part or a header part. If it is the data part, the data part processing of step # 2 is executed. If it is not the data part, the header part processing of step # 3 is executed. Step #
After the execution of step 2, the end sector is determined in step # 4, and if the current sector is the end sector (one round of the disk), all the processing ends. If not the end sector, step # 1
Return to

Next, at step # 2 in FIG.
Will be described in detail. In step # 2-1, it is determined whether the currently reproduced sector is the start sector.
If it is determined that the sector is the start sector, the parameter is set in step # 2-2, and after the setting is completed, step # 2-3 is executed. If it is determined that the sector is not the start sector, step # 2-3
Is measured. In step # 2-4, the jitter value of the measurement result is integrated. In step # 2-5, the sector count is incremented by one, and the data section processing ends.

Subsequently, step # in FIG.
The header processing of No. 3 will be described in detail. Step # 3-1
Then, it is determined whether the currently reproduced sector is the start sector. If it is determined that the sector is the start sector, the parameter is set in step # 3-2, and after the setting is completed, step # 3-3 is executed. If it is determined that the sector is not the start sector, step # 3-
Then, the number of errors is measured (measurement of the total of the addresses NG among the sectors PID1 to PID4), and after the measurement, step # 3-4 is executed. In step # 3-4, the number of errors in the measurement result is added. In step # 3-5, the sector count is incremented by one, and the header section processing ends.

By the above steps # 1 to # 4, the number of errors and the jitter value when the focus position parameter is changed for each of the header portion and the data portion can be obtained. The optimum focus parameter value is known.

By performing simultaneous learning of the header section and the data section, the optimum parameters of the header section and the data section can be obtained without increasing the conventional optimum parameter learning time, thereby improving the quality of the reproduced signal. Can be done. Further, the control for optimizing the focus position has been described by way of example, but the optimum parameter obtained in the same manner can be applied to the control of the tracking position and the waveform equalization (equalizer) coefficient.

[0033]

As described above, according to the present invention, a DVD-
In an optical disk device capable of reproducing a RAM disk, it is possible to realize an optical disk device capable of simultaneously optimizing parameters of a header portion and a data portion and improving the quality of a reproduced signal without increasing a learning time at the time of startup.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an optical disk device according to a first embodiment of the present invention.

FIG. 2 is a flowchart of simultaneous parameter learning.

FIG. 3 is a DVD-RAM disk format diagram.

FIG. 4 is a configuration diagram of a conventional optical disk device.

FIG. 5 is a diagram illustrating a relationship between a focus position and jitter.

[Description of Signs] 101, 501 PUM 102, 502 Optical Disk 103, 503 Signal Detection Unit 104, 504 Waveform Equalization Unit 105, 505 Slice / PLL Unit 106, 506 Demodulation / Error Correction Unit 107, 507 Servo Unit 108, 508 Drive Unit 109, 509 Control unit 110, 510 Jitter measurement unit 111 Error number measurement unit

Claims (4)

[Claims] 1. An optical disk device for performing a read operation of an optical disk by correcting a control signal for the optical pickup when starting a read operation of reading an information signal from an optical disk on which information is recorded by an optical pickup, wherein: A jitter measuring means for outputting a jitter integrated signal based on the information signal, an error number measuring means for detecting an error included in the information signal, adding an error number of the information signal and outputting an error added signal, and Control arithmetic means for generating a learning teacher signal for correcting a control signal for controlling the operation of the optical pickup based on the integration signal and the error addition signal, wherein the read operation is started based on the learning teacher signal at the start of the read operation. An optical disk device for performing a read operation on an optical disk after correcting a control signal. 2. The optical disk device according to claim 1, wherein the sector of the information recorded on the optical disk has a header section and a data section, and each read characteristic for the header section and the data section is best. An optical disk device, wherein a control operation unit generates the learning teacher signal so that the learning teacher signal is generated. 3. A data reproducing method for correcting a control signal for the optical pickup and executing a reading operation of the optical disk when starting a reading operation of reading an information signal from the optical disk on which information is recorded by an optical pickup, comprising: A jitter integration step for integrating a jitter component included in the information signal, and an error addition step of detecting an error included in the information signal and adding the number of errors of the signal,
A learning signal generating step of generating a learning teacher signal for correcting a control signal for controlling the reading operation of the optical pickup by the jitter integration signal step and the error adding step, wherein the learning signal generation is performed when the reading operation is started. A data reproducing method characterized by executing a step. 4. The data reproducing method according to claim 3, wherein the sector of the information recorded on the optical disc has a header section and a data section, and each of the read characteristics for the header section and the data section is best. Performing the learning signal generating step so that