JPH10177768A - Disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent degradation of an error rate when a zone is switched during continuous reproduction in a reproduction system using an adaptive type digital equalizer, when a multi-zone constant angular velocity (MZ-CAV) system is adopted. SOLUTION: Reproduced data PD is obtained by processing digitally a reproduced signal by a equalization/discrimination device 46. An equalization characteristic of the equalization/discrimination device 46 is set by giving equalization device parameters EQP from a storage circuit 47. When reproducing operation of the prescribed zone is started, the parameters EQP of the prescribed zone is read out from a memory 49 and loaded in the storage circuit 47, and an equalization characteristic of the equalization/discrimination device 46 is made a characteristic corresponding to the prescribed zone. Update data RND is obtained by a update circuit 48 during reproducing the prescribed zone and the parameters EQP stored in the storage circuit 47 is updated any time, and an equalization characteristic is changed adaptively in accordance with a reproduced signal. When a zone is switched during continuous reproduction, the equalization characteristic of the equalization/discrimination device 46 is instantly changed to an equalization characteristic corresponding to a zone after switching.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a multi-zone C
The present invention relates to a disk device which handles a disk medium adopting the recording format of the AV system and performs a waveform equalization process on a reproduced signal from the disk medium by an adaptive digital equalizer. More specifically, the present invention relates to a disk device in which, when a zone is switched during continuous playback, an optimal equalizer parameter is instantaneously given to an adaptive digital equalizer so that an error rate does not deteriorate when the zone is switched. Things.

[0002]

2. Description of the Related Art A disk drive (disk drive) using a disk medium such as a magneto-optical disk or a phase change disk is mainly used as a peripheral device such as a personal computer, and is fixed in a position like a large-capacity floppy disk drive. It is getting. However, with the development of high-speed and high-density recording / reproducing technology, needs as digital recording / reproducing equipment for image information are increasing.

In a disk device including a hard disk drive, unlike a video tape recorder (VTR),
Continuous image information can be recorded in a discontinuous area, and data in the discontinuous area can be randomly accessed and reproduced as continuous image information. Such random access is very important for realizing so-called non-linear transmission or editing when the above-described disk device is viewed as a recording / reproducing device for image information in a broadcasting station or post-production. It is a characteristic.

In practice, image information cannot be recorded / reproduced at a high speed and a large capacity exceeding the VTR. However, as the demand for non-linear transmission or editing linked to a workstation increases, the above-mentioned disk device becomes
It is beginning to occupy an important position as an image information recording / reproducing device in a broadcasting station or post-production.

In an optical disk device, CAV (Constant A)
ngular Velocity) method is the most basic method. Since data is recorded at a constant data rate because the angular velocity is constant, the linear density is high on the inner circumference and low on the outer circumference. As a result, there is a problem that the recording capacity per disk medium is reduced because the linear density that can be used in the outer periphery is not used.

On the other hand, a CLV (Constant Linear)
The Velocity method is a method that can maximize the recording capacity. Since the linear velocity is constant, if data is recorded at a constant data rate, the linear density becomes constant from the inner circumference to the outer circumference. However, in the CLV method, it is necessary to continuously change the spindle rotation speed from the inner circumference to the outer circumference, and thus there is a problem that a control system becomes very complicated and an access speed becomes slow.

The multi-zone CAV (MZ-CAV) system utilizes the advantage that the rotation control of the CAV system is simple and improves the disadvantage that the recording capacity is small.
In this method, while the spindle speed is kept constant, it is divided into several zones in the radial direction from the inner circumference to the outer circumference,
The data rate is set higher in the zone on the outer peripheral side. In this case, since the target is the CLV method, it is fundamental to select a data rate so that the linear density at the innermost circumference of each zone is constant.

FIG. 5 shows an example of the configuration of a reproducing system of a magneto-optical disk device that handles a magneto-optical disk employing the MZ-CAV system.

In FIG. 1, a reproduced signal _SMO from an optical head (optical pickup) 101 is converted into an analog equalizer 102.
And the waveform is equalized with desired equalization characteristics. The waveform-equalized reproduction signal output from the analog equalizer 102 is supplied to a comparator 103, and is converted into a binary signal by comparing the magnitude with a certain threshold. Comparator 10
The binarized signal output from 3 is a PLL (phase-locked signal).
oop) circuit 104, and the PLL circuit 104 reproduces the clock signal CK _MO from the binarized signal.

A binary signal output from the comparator 103 is supplied to a D flip-flop 105. In the D flip-flop 105, the binary signal is latched by a clock signal CK _{MO to} generate the reproduced data PD.
Is obtained. The reproduced data PD is supplied to a digital signal processing circuit 106, which performs demodulation processing (decoding processing of a recording modulation code), error correction processing, and the like on the reproduced data PD to output data Dout.
Is obtained.

Further, in the MZ-CAV system, since the linear velocity and the data rate are different in each zone, the frequency characteristics of the reproduced signal _SMO are different in each zone, and the equalization characteristics of the analog equalizer 102 are also different in each zone. We need to change it. Therefore, an adjustable parameter such as a gain and a cutoff frequency is switched and supplied to the analog equalizer 102 for each zone from a system controller 107 for controlling the entire system to the analog equalizer 102 through a digital-to-analog (D / A) converter 108. Is done.

FIG. 6 shows another example of the configuration of a reproducing system of a magneto-optical disk device which handles a magneto-optical disk employing the MZ-CAV system.

[0013] In Figure, the reproduced signal S _MO from the optical head 201 is supplied to an analog equalizer 202, it is waveform equalized by the desired equalization characteristics. The waveform-equalized reproduced signal output from the analog equalizer 202 is output to a comparator 203.
And is converted into a binary signal by a magnitude comparison with a certain threshold value. Then, the binary signal output from the comparator 203 is supplied to the PLL circuit 204,
The LL circuit 204 uses the clock signal CK _MO from the binarized signal.
Is played.

A reproduced signal output from the analog equalizer 202 and subjected to waveform equalization is A / D (analog-to-digit).
l) Clock signal CK _MO supplied to converter 205
Is converted to a digital signal. The output data of the A / D converter 205 is supplied to a Viterbi decoder 206. The Viterbi decoder 206 performs a maximum likelihood decoding process (identification process) on the output data and outputs the reproduced data P.
D is obtained. Then, the reproduction data PD is supplied to the digital signal processing circuit 207,
In, demodulation processing, error correction processing, and the like are performed on the reproduction data PD to obtain output data Dout.

A D / A converter 209 is provided by a system controller 208 for controlling the entire system.
Adjustable parameters such as gain and cutoff frequency are switched and supplied to the analog equalizer 202 for each zone. Thereby, the equalization characteristics of the analog equalizer 202 are changed for each zone in accordance with the frequency characteristics of the reproduced signal _SMO .

In the reproduction system shown in FIGS. 5 and 6, the adjustable parameters such as the gain and the cut-off frequency are switched for each zone as described above, so that the analog equalizers 102 and 202 are controlled. The equalization characteristic is changed in each zone. However, with the increase in recording density, equalizers are required to have more strict equalization characteristics, and LMS (least mean square) is required.
e) An adaptive digital equalizer such as an adaptive transversal filter using an algorithm or the like, a non-linear canceller which is a kind of nonlinear equalizer, and a decision feedback Viterbi decoder has begun to be required.

FIG. 7 shows still another example of the configuration of a reproducing system of a magneto-optical disk device for handling a magneto-optical disk employing the MZ-CAV system, in which an adaptive digital equalizer is used. Here, the digital equalizer and the discriminator can be separated like a combination of a transversal filter and a comparator, a transversal filter and a Viterbi decoder, but in the case of a non-linear canceller or a decision feedback type Viterbi decoder, etc. In FIG. 3, since a part functioning as an equalizer and a part functioning as a discriminator cannot be separated, the block is shown as a digital equalizer / discriminator in one block.

[0018] In Figure, the reproduced signal S _MO from the optical head 301 is supplied to an analog equalizer 302 waveform equalization. To the analog equalizer 302, adjustable parameters such as gain and cutoff frequency are switched and supplied for each zone from a system controller 303 for controlling the entire system via a D / A converter 304. Accordingly, the equalization characteristic of the analog equalizer 302 is
It changes in each zone in accordance with the frequency characteristics of the reproduction signal _SMO .

The waveform-equalized reproduced signal output from the analog equalizer 302 is supplied to a comparator 305, and is converted into a binary signal by comparing the magnitude with a threshold value. Then, 2 output from the comparator 305
The digitized signal is supplied to a PLL circuit 306, where the clock signal CK _MO is reproduced from the binarized signal.

Further, the waveform equalized reproduced signal outputted from the analog equalizer 302 is supplied to the A / D converter 307, and converted into a digital signal by using the clock signal CK _MO. The output data of the A / D converter 307 is supplied to a digital equalizer / identifier 308. The digital equalizer / identifier 308 performs digital waveform equalization and identification on the output data. The reproduction data PD is obtained.

In this case, the digital equalizer / identifier 308
Is supplied with an equalizer parameter EQP held in a storage circuit 309 composed of a register or the like, and an equalization characteristic is determined. Here, the equalizer parameter EQP is a tap gain when the digital equalizer is formed of a transversal filter, and is an intersymbol interference data when the digital equalizer is formed of a non-linear canceller. In the case where the digital equalizer is constituted by a decision feedback type Viterbi decoder, it is an amplitude reference value.

When the reproducing operation is started, the nonvolatile memory 3 is controlled by the system controller 303.
11, the initial value of the equalizer parameter EQP is read out, and the initial value of the equalizer parameter EQP is stored in the storage circuit 3.
09 is loaded. As a result, the equalization characteristics of the digital equalizer / identifier 308 are initialized.

During the reproducing operation, the update circuit 310 obtains update data RND for updating the equalizer parameter EQP by an LMS algorithm or the like based on the input / output data of the digital equalizer / identifier 308. , The equalizer parameter EQP held in the storage circuit 309
Is updated at any time by the update data RND. As a result, the equalization characteristics of the digital equalizer / identifier 308 are adaptively updated according to the reproduced signal.

When the reproduction operation is completed, the storage circuit 30 is controlled by the system controller 303.
The equalizer parameter EQP stored in 9 is stored in the nonvolatile memory 311 as an initial value of the equalizer parameter EQP, and is used when starting the next reproduction operation.

The reproduced data PD output from the digital equalizer / discriminator 308 is supplied to the digital signal processing circuit 3.
The processing circuit 312 supplies the reproduced data P
D is subjected to demodulation processing, error correction processing, and the like, and output data Dout is obtained.

[0026]

In the configuration example of the reproduction system shown in FIG. 7, the frequency characteristic of the reproduction signal changes discontinuously every time the zone is switched by random access.
It takes time until the equalizer parameter EQP converges, and during that period, there is a problem that the error rate deteriorates.

In the case of a disk device as a computer peripheral device, when an error is detected in the reproduction data PD, it is possible to retry the reproduction operation or wait until the equalizer parameter EQP converges. is there. However, a disk device that reproduces image information is inconvenient because images are interrupted.

In view of the above, the present invention provides a disk device in which the error rate does not deteriorate even when the zone is switched during continuous reproduction.

[0029]

According to the present invention, there is provided a disk apparatus comprising: a signal reproducing section for obtaining a reproduced signal from a disk medium employing a multi-zone CAV method; And a digital signal processing section for processing reproduction data output from the digital equalization section to obtain output data. The digital equalizer includes a digital equalizer that can control an equalization characteristic by an externally applied equalizer parameter, a parameter storage that stores an equalizer parameter corresponding to each zone of the disk medium, Parameter reproduction means for selecting equalizer parameters corresponding to the predetermined zone from the parameter storage means to give to the digital equalization means when the reproduction of the predetermined zone of the disk medium is started by the signal reproduction section; After the reproduction of the zone is started, there is provided parameter updating means for updating the equalizer parameters of the digital equalizing means based on the input / output data of the digital equalizing means.

The disk medium employs a multi-zone CAV method. For example, after a waveform equalization process is performed on the reproduction signal of the disk medium in an analog manner, a waveform equalization process is performed on a digital basis to obtain reproduction data. Processing such as identification, demodulation, and error correction is performed on the reproduced data to obtain output data.

When the reproduction of the predetermined zone of the disk medium is started, an equalizer parameter corresponding to the predetermined zone is selected from the parameter storage means and given to the digital equalization means. With this, if the optimum parameters for the predetermined zone are stored in advance in the parameter storage means, the optimum equalizer parameters are instantaneously given to the digital equalization means when the zone is switched. Is converged immediately after the zone is switched, and it is possible to prevent the error rate from deteriorating when the zone is switched.

After the reproduction of the predetermined zone is started, the equalizer parameters of the digital equalizer are updated as needed based on the input / output data of the digital equalizer. As a result, the equalization characteristics of the digital equalizer are adaptively changed.

When the reproduction of the predetermined zone is completed, the equalizer parameters finally remaining in the digital equalizing means are stored in the parameter storing means. Thereby, when the reproduction of the predetermined zone is started next time, it becomes possible to provide the digital equalizer with the optimal equalizer parameters.

In the parameter storage means, for example, after the disk medium is mounted on the disk device main body, the operation of starting the initial adjustment means is operated automatically or by the user to store the data in the zone where the disk medium is recorded. The corresponding equalizer parameters are stored. In this case, the recorded zones are reproduced, and the equalizer parameters of each zone are converged. The converged equalizer parameters of each zone are stored. This makes it possible to store the equalizer parameters corresponding to each zone already recorded in the parameter storage unit even for a newly mounted disk medium, and the error rate deteriorates when the zone is switched during continuous playback. Can be prevented.

[0035]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of a magneto-optical disk device 10 as an embodiment. This disk device 10 handles a magneto-optical disk 11 employing a multi-zone CAV method.

The disk device 10 is a magneto-optical (MO)
Spindle motor 1 for rotationally driving disk 11
2 and a magnetic head 1 for generating an auxiliary magnetic field during recording
3 and an optical head (optical pickup) 14 including a laser diode, an objective lens, a photodetector, a preamplifier, and the like. The magnetic head 13 and the optical head 14 are arranged to face each other with the magneto-optical disk 11 therebetween.

Also, the disk device 10 includes the optical head 1
And a system controller 16 that includes a microcomputer and controls the entire system. Here, the microcomputer, as is well known,
CPU (central processing unit) that actually performs control, measurement, etc., and a ROM (read onl
RAM (random access memory) for storing data temporarily needed in the process of the above control, measurement, etc.
have.

The laser drive circuit 15 is supplied with the output laser power detection output S _DP from the optical head 14,
The power control signal _SPC is supplied from the system controller 16 through the D / A converter 17 and the optical head 14
Is controlled so that the power of the laser beam output from the laser diode becomes the optimum power at the time of recording and at the time of reproduction, respectively.

At the time of recording, the recording data RD output from a channel encoder described later
Is supplied. Therefore, the laser diode of the optical head 14 is driven by the laser drive circuit 15 so that the power changes according to the recording data RD. As a result, the recording data RD is magneto-optically recorded in the data section (MO area) of the magneto-optical disk 11.

The reproduction signal _SMO from the data section (MO area) of the magneto-optical disk 11 is obtained from the optical head 14 at the time of reproduction, and the pre-format section (ROM) of the magneto-optical disk 11 at the time of recording and reproduction. reproduced signal S _RF from the area) can be obtained. Further, the optical head 14
From the tracking error signal obtained by the conventionally known detection method E _T, and a focus error signal E _F is output.

FIG. 2 shows the recording format of each sector of the magneto-optical disk 11. At the head of each sector, a pre-format section in which addresses and the like are recorded in advance by pits is arranged. Following this pre-format section, an ALPC (Auto Laser Power) as a test section for controlling the level of output laser power is provided. Control)
Department is arranged. Further, a data section is arranged following the ALPC section.

The disk device 10 has a servo circuit 18 having a CPU. In the servo circuit 18,
Error signal E _T outputted from the optical head 14, E _F is supplied. The operation of the servo circuit 18 is controlled by the system controller 16. The servo circuit 18 controls an actuator 19 including a tracking coil, a focus coil, and a linear motor for moving in the radial direction, and performs tracking and focus servo of the optical head 14, and also moves the optical head 14 in the radial direction. Is controlled. Further, the rotation of the spindle motor 12 is controlled by the servo circuit 18 so that the magneto-optical disk 11 rotates at a constant angular velocity.

Also, the disk device 10 includes the optical head 1
4 reproduced signal S from the preformat section
An analog equalizer 21 for performing analog waveform equalization processing on _RF and an address decoder 22 for processing an output signal of the analog equalizer 21 to obtain address data AD. I have.

To the analog equalizer 21, adjustable parameters such as gain and cut-off frequency are switched and supplied from the system controller 16 through the D / A converter 23 for each zone. Thereby, the analog equalizer 2
1 equalization characteristics according to the frequency characteristics of the reproduced signal S _RF, is adapted to vary for each zone.

The disk device 10 has a data interface 31 for receiving input data Din from an external device, for example, a host computer, and a data interface 31 for adding an error correction code to the input data Din received by the data interface 31. It has an ECC encoder 32 and a channel encoder 33 for performing a modulation process (recording modulation encoding process) on output data of the ECC encoder 32 to obtain recording data RD. here,
From the ECC encoder 32, the sector data recorded in the data section of each sector is sequentially output, supplied to the channel encoder 33, and subjected to modulation processing.

Also, the disk device 10 includes the optical head 1
An analog equalizer 41 for performing analog waveform equalization processing on the reproduced signal _SMO from the data portion output from the data section 4 and a reproduced signal whose waveform is equalized by the analog equalizer 41 are provided. The comparator 42 converts the value into a binary signal by comparing the value with a threshold value, the PLL circuit 43 for reproducing the clock signal CK _MO from the binary signal output from the comparator 42, and the analog equalizer 41. and an a / D converter 44 for converting a digital signal waveform equalized reproduced signal using the clock signal CK _MO.

To the analog equalizer 41, adjustable parameters such as gain and cutoff frequency are switched and supplied from the system controller 16 through the D / A converter 45 for each zone. Thereby, the analog equalizer 4
The equalization characteristic of No. 1 is changed for each zone in accordance with the frequency characteristics of the reproduced signal _SMO .

The disk device 10 includes a digital equalizer / identifier 46 for digitally performing waveform equalization processing and identification processing on output data of the A / D converter 44 to obtain reproduction data PD, An equalizer parameter EQP to be given to the equalizer / identifier 46 is held, and stored in the storage circuit 47 based on input / output data of the digital equalizer / identifier 46 and a storage circuit 47 composed of a register and the like. Therefore, an update circuit 48 for obtaining update data RND for updating the equalizer parameter EQP provided to the digital equalizer / identifier 46 by an LMS algorithm or the like.

Here, the digital equalizer / identifier 46 is
It is composed of a combination of a transversal filter and a comparator, a transversal filter and a Viterbi decoder, or a non-linear canceller or a decision feedback Viterbi decoder. Equalizer parameter EQP
Is the tap gain when the digital equalizer is composed of a transversal filter, is the intersymbol interference data when the digital equalizer is composed of a non-linear canceller, and is determined by the digital equalizer. In the case of a feedback type Viterbi decoder, it is an amplitude reference value.

The disk device 10 includes a non-volatile memory 49 in which equalizer parameters EQP respectively corresponding to the recorded zones of the magneto-optical disk 11 mounted on the main body of the device are stored in advance. And an operation unit 50 on which keys and the like are arranged. The non-volatile memory 49 and the operation unit 50 are connected to the system controller 16, respectively.

When the reproduction operation of the predetermined zone of the magneto-optical disk 11 is started, the equalizer parameter EQP corresponding to the predetermined zone is read from the non-volatile memory 49 under the control of the system controller 16. The modifier parameter EQP is loaded into the storage circuit 47 described above. Conversely, when the reproduction operation of the predetermined zone of the magneto-optical disk 11 is completed, the equalizer parameter EQP held in the storage circuit 47 is stored in the non-volatile memory 49 in the predetermined zone under the control of the system controller 16. It is stored as the corresponding equalizer parameter EQP.

The user operates the operation unit 50 to mount the magneto-optical disk 11 and then mount the magneto-optical disk 1.
The start of the initial adjustment mode for storing the equalizer parameters EQP respectively corresponding to the one recorded zone in the nonvolatile memory 49 can be operated. The operation unit 50
By the operation described above, the setting can be made so that the initial adjustment mode is automatically started when the magneto-optical disk 11 is mounted. Further, when the recording is subsequently performed in a zone that has not been recorded in the initial adjustment mode by the operation of the operation unit 50, the equalizer parameter EQP corresponding to the zone is automatically stored in the nonvolatile memory 49. You can also set it.

The disk device 10 includes a channel decoder 51 for demodulating (decoding a recording modulation code) the reproduction data PD output from the digital equalizer / identifier 46, An ECC decoder 52 that performs error detection / correction processing on output data, and error-corrected data output from the ECC decoder 52 are output data Dout.
It has an external, for example, a data interface 53 for sending to a host computer.

Here, the ECC decoder 52 supplies the system controller 16 with the magneto-optical disk 11
The disc management information to be reproduced from the lead-in area when is mounted is supplied. As described later, in the operation of the initial adjustment mode, the system controller 16
Using this disc management information, it can be determined whether or not the disc is a recorded disc, and if the disc is a recorded disc, which zone has been recorded.

The operation of the magneto-optical disk device 10 shown in FIG. 1 will be described. First, the operation at the time of recording will be described. At the time of recording, after input data Din supplied from the outside, for example, from a host computer, is received by the data interface 31, an error correction code is added by the ECC encoder 32. Then, the sector data recorded in the data portion of each sector sequentially output from the ECC encoder 32 is supplied to the channel encoder 33 and modulated to obtain the recording data RD. The recording data RD is supplied to the laser drive circuit 15, and the recording data RD is magneto-optically recorded on the data section of the magneto-optical disk 11.

Next, the operation at the time of reproduction will be described. At the time of reproduction, the magneto-optical disk 11 is
The reproduction signal _SMO is reproduced from the data section of the predetermined zone of
This reproduced signal _SMO is supplied to an analog equalizer 41, where the waveform is equalized in an analog manner. In this case, the analog equalizer 41 is supplied from the system controller 16 with parameters such as the gain and the cutoff frequency corresponding to the above-mentioned predetermined zone, and the analog equalizer 41 provides the equalization characteristic corresponding to the predetermined zone. It has become.

The waveform-equalized reproduction signal output from the analog equalizer 41 is supplied to a comparator 42, and is converted into a binary signal by comparing the magnitude with a threshold value. Then, this binarized signal is supplied to the PLL circuit 43, and the clock signal CK _MO is reproduced.

[0058] The waveform equalized reproduced signal outputted from the analog equalizer 41 is supplied to the A / D converter 44, it is converted into a digital signal by using the clock signal CK _MO. The output data of the A / D converter 44 is supplied to a digital equalizer / discriminator 46. The digital equalizer / discriminator 44 performs digital waveform equalization and identification on the output data. The reproduction data PD is obtained.

In this case, the equalization characteristic of the digital equalizer / identifier 46 is set by the equalizer parameter EQP given from the storage circuit 47.

That is, when the reproduction operation of the predetermined zone is started, under the control of the system controller 16,
The equalizer parameter EQP of the predetermined zone is read from the non-volatile memory 49, and the equalizer parameter EQP is read.
Is loaded into the storage circuit 47. Thereby, the equalization characteristics of the digital equalizer / identifier 46 are initialized to the characteristics corresponding to the predetermined zone.

While the predetermined zone is being reproduced, the update circuit 48 obtains update data RND for updating the equalizer parameter EQP based on the input / output data of the digital equalizer / identifier 46. The equalizer parameter EQP held in the circuit 47 is updated at any time by the update data RND. This allows digital equalization and
The equalization characteristic of the discriminator 46 is adaptively changed according to the reproduced signal.

When ending the reproduction operation of the predetermined zone,
The storage circuit 4 is controlled by the system controller 16.
The equalizer parameter EQP held in 7 is stored in the non-volatile memory 47 as the equalizer parameter EQP corresponding to the above-described predetermined zone, and is used when starting the next reproduction operation of the predetermined zone. .

When a zone is switched during continuous playback,
An operation for ending the reproduction operation of the above-mentioned predetermined zone,
The operation at the time of starting the reproduction operation of the predetermined zone is instantaneously performed, and after the equalizer parameter EQP corresponding to the zone before the switching is stored in the non-volatile memory 49, the storage circuit 47 is stored in the non-volatile memory 49. Is loaded with the equalizer parameters corresponding to the zone after the switching. Therefore, when a zone is switched during continuous playback, the equalizer parameter EQP corresponding to the zone after the switching is instantaneously loaded into the storage circuit 47, and the equalization characteristic of the digital equalizer / identifier 46 is switched. Initialized to the equalization characteristics corresponding to the later zone.

The reproduced data PD output from the digital equalizer / identifier 46 is demodulated by the channel decoder 51 and then error-corrected by the ECC decoder 52. , For example, to the host computer as output data Dout.

Next, the operation in the initial adjustment mode will be described. As described above, the initial adjustment mode is started when the user operates the operation unit 50 to start the initial adjustment mode after mounting the magneto-optical disk 11. Alternatively, when the initial adjustment mode is set to be automatically started when the magneto-optical disk 11 is mounted by a user's operation of the operation unit 50, the magneto-optical disk 11
The initial adjustment mode is automatically started when the device is mounted.

FIG. 3 is a flowchart showing the control operation of the system controller 16 in the initial adjustment mode.

When the initial adjustment mode starts, step S
At T1, it is determined whether or not the mounted magneto-optical disk 11 is a recorded disk. This determination is made using, for example, disk management information reproduced from the lead-in area when the magneto-optical disk 11 is mounted. If the disc is not a recorded disc, there is no need for adjustment, so the initial adjustment mode is ended in step ST2.

If the disc is a recorded disc in step ST1, the recorded zones are reproduced in order, and the equalizer parameters EQP converged in the reproduction state of each zone are replaced with the equalizer parameters corresponding to each zone. The operation shifts to the operation of storing the data in the nonvolatile memory 49 as the EQP.

That is, in step ST3, i = 1 is set, and in step ST4, it is determined whether or not the zone i has been recorded. This determination is also made using the above-described disk management information. If the zone i has been recorded, the equalizer parameter EQP of the zone i stored in the non-volatile memory 49 is stored in the storage circuit 4 in step ST5.
7 and then in step ST6, the zone i
To play. Then, in step ST7, the storage circuit 4
It is determined whether or not the change of the equalizer parameter EQP held in 7 has ceased, that is, whether or not the equalizer parameter EQP has converged. When it is determined that the equalizer parameter EQP has converged, the process proceeds to step ST8.
And the equalizer parameter E held in the storage circuit 47.
The QP is stored in the nonvolatile memory 49 as the equalizer parameter EQP of the zone i, and the process proceeds to step ST9.

If it is determined in step ST4 that the zone i has not been recorded, it is not necessary to store the equalizer parameter EQP corresponding to the zone i in the non-volatile memory 49, so that the process immediately proceeds to step ST9.

At step ST9, it is determined whether or not i = M. Here, M indicates the total number of zones on the magneto-optical disk 11. If i = M, it means that the processing for all the zones of the magneto-optical disk 11 has been completed, and thus the initial adjustment mode is ended in step ST2. On the other hand, if i = M is not satisfied, in step ST10,
i is incremented, and thereafter, the process returns to step ST4 to perform processing for the next zone.

As described above, by executing the initial adjustment mode shown in the flowchart of FIG.
Equalizer parameters EQ corresponding to each recorded zone of
P will be stored in the non-volatile memory 49. The non-volatile memory 49 has, for example, an equalizer parameter E corresponding to each zone of the magneto-optical disk 11 at the time of manufacture.
Although the initial value of QP is stored, by executing the above-described initial adjustment mode, the equalizer parameter EQP corresponding to each recorded zone of the magneto-optical disk 11 actually mounted is stored in the nonvolatile memory 49. Can be stored in

Next, when recording is performed in a zone that has not been recorded in the initial adjustment mode by a user's operation of the operation unit 50, the equalizer parameter EQP corresponding to that zone is stored in the nonvolatile memory 49. The operation in the case where the setting is made so that the information is automatically stored will be described. In this case, after the recording is completed, the same operation as that in steps ST5 to ST8 in the flowchart shown in FIG. 3 is performed on the newly recorded zone, and the equalizer parameter corresponding to the zone is performed. The EQP is stored in the non-volatile memory 49.

As described above, in the present embodiment, when the reproduction of the predetermined zone of the magneto-optical disk 11 is started, the equalizer parameter EQP corresponding to the predetermined zone stored in the nonvolatile memory 49 is stored in the storage circuit. 47 is instantly loaded. Therefore, if the optimum equalizer parameter EQP corresponding to the predetermined zone is stored in the non-volatile memory 49 by executing the initial adjustment mode or the like, the digital equalization is performed when the zone is switched during the continuous reproduction. The equalization characteristics of the discriminator 46 are instantaneously initialized to the characteristics corresponding to the zone after the switching. Therefore, it is possible to prevent the error rate from being deteriorated when the zone is switched during the continuous reproduction.

When the reproduction of the predetermined zone is completed, the equalizer parameter EQP finally remaining in the storage circuit 47 is stored in the nonvolatile memory 49 as the equalizer parameter EQP of the predetermined zone. Therefore, when the reproduction of the predetermined zone is started next time, the storage circuit 47
, The optimal equalizer parameter EQP can be loaded.

Further, by executing the initial adjustment mode, the equalizer parameters EQP corresponding to each recorded zone can be stored in the non-volatile memory 49 for the newly mounted magneto-optical disk 11, thereby enabling continuous reproduction. It is possible to prevent the error rate from deteriorating when the zone is switched.

Further, for the zone which has not been recorded in the initial adjustment mode but has been recorded thereafter, the non-volatile memory 49 stores the equalizer parameter E corresponding to the zone.
The QP can be stored, and it is possible to prevent the error rate from deteriorating when switching to that zone during continuous playback.

In the above-described embodiment, the storage circuit 47 holds the equalizer parameter EQP of one zone, but such a storage circuit corresponds to the total number M of zones of the magneto-optical disk 11. A configuration is also conceivable in which M pieces are provided, each of which holds an equalizer parameter EQP corresponding to each zone, and switches the M pieces of memory circuits according to the reproduction zone.

FIG. 4 shows the configuration in that case. M
The storage circuits 47 _{1 to} 47 _M are connected to the digital equalizer / identifier 46 via the selector 54 and to the updating circuit 48 via the selector 555. And
The operation of the selectors 54 and 55 is controlled by the system controller 16.
And a storage circuit corresponding to the reproduction zone is selectively connected to the digital equalizer / identifier 46 and the update circuit 48.

In this case, the equalizer parameter E of each zone
The non-volatile memory 49 in FIG. 1 for storing the QP becomes unnecessary. When storing the equalizer parameter EQP corresponding to a certain recorded zone in the initial adjustment mode, a storage circuit corresponding to the recorded zone is selected, and the recorded zone is reproduced and equalized. Container parameter E
It is only necessary to converge the QP.

In the above-described embodiment, the present invention is applied to the magneto-optical disk drive 10.
Of course, the present invention can be similarly applied to a disk device that handles other disk media such as a phase change disk employing the multi-zone CAV method.

[0082]

According to the present invention, when reproduction of a predetermined zone of a disk medium is started, an equalizer parameter corresponding to the predetermined zone is selected from the parameter storage means and given to the digital equalization means. If the optimal parameters for the predetermined zone are stored in advance in the parameter storage means, the optimal equalizer parameters are instantaneously given to the digital equalizing means when the zone is switched. Immediately after the zone is switched, the state converges, and it is possible to prevent the error rate from being deteriorated when the zone is switched during continuous playback.

When the reproduction of the predetermined zone is completed,
By storing the equalizer parameters finally remaining in the digital equalizing means in the parameter storage means, the next time the reproduction of the predetermined zone is started, the optimal equalizing means for the digital equalizing means is used. Equalizer parameters can be provided.

Also, after the disk medium is mounted on the disk device main body, when the operation of starting the initial adjustment means is operated automatically or by the user, the parameters stored in the parameter storage means correspond to the recorded zones of the disk medium. By storing the equalizer parameters, the equalizer parameters corresponding to each zone already recorded in the parameter storage unit can be stored even for a newly mounted disk medium, and the zones are switched during continuous playback. In this case, it is possible to prevent the error rate from deteriorating.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a magneto-optical disk device as an embodiment.

FIG. 2 is a diagram showing a recording format of each sector.

FIG. 3 is a flowchart illustrating a control operation of a system controller in an initial adjustment mode.

FIG. 4 is a block diagram showing a configuration of a main part of a magneto-optical disk device as another embodiment.

FIG. 5 is a block diagram showing a configuration example of a reproducing system of a conventional magneto-optical disk device (MZ-CAV system).

FIG. 6 is a block diagram showing another configuration example of a reproducing system of a conventional magneto-optical disk device (MZ-CAV system).

FIG. 7 is a block diagram showing a configuration example of a reproduction system of a magneto-optical disk device (MZ-CAV system) using an adaptive digital equalizer.

[Explanation of symbols]

Reference numeral 10: magneto-optical disk device, 11: magneto-optical disk, 13: magnetic head, 14: optical head
Reference numeral 15: laser drive circuit, 16: system controller, 18: servo circuit, 19: actuator, 21, 41: analog equalizer, 22: address decoder, 32 ... ECC encoder, 33
..Channel encoders, 42 comparators, 4
3 ... PLL circuit, 44 ... A / D converter, 4
6 ... Digital equalizer / identifier, 47, 47 _{1 to} 47 _M
... Storage circuit, 48 ... Update circuit, 49 ... Non-volatile memory, 50 ... Operation unit, 51 ... Channel decoder, 52 ... ECC decoder, 54, 55 ...
selector

Claims (7)

[Claims] 1. A signal reproducing unit for obtaining a reproduction signal from a disk medium employing a multi-zone CAV method; a digital equalization unit for digitally performing waveform equalization processing on the reproduction signal; A digital signal processing section for processing reproduction data output from the section to obtain output data, wherein the digital equalization section includes digital equalization means capable of controlling an equalization characteristic by an externally provided equalizer parameter. Parameter storage means for storing the equalizer parameters corresponding to each zone of the disk medium; and when the signal reproduction section starts reproduction of the predetermined zone of the disk medium, the parameter storage means stores the predetermined parameter. Parameter selecting means for selecting an equalizer parameter corresponding to a zone and giving the selected parameter to the digital equalizing means; After the reproduction of the predetermined zone is started by the signal reproducing unit, the signal reproducing unit has parameter updating means for updating an equalizer parameter of the digital equalizing means based on input / output data of the digital equalizing means. Characteristic disk device. 2. The digital equalizer further includes parameter storage means for storing, in the parameter storage means, equalizer parameters of the digital equalizer when the reproduction of the predetermined zone is completed by the signal reproducing means. 2. The disk device according to claim 1, wherein the disk device has: 3. The digital equalizer further comprises an initial adjustment unit for storing the equalizer parameter corresponding to a recorded zone of the disk medium in the parameter storage unit. 2. The disk device according to 1. 4. The initial adjustment means stores the equalizer parameters of the digital equalization means converged in a state where the recorded zone is being reproduced by the signal reproducing unit in the parameter storage means. 4. The disk device according to claim 3, wherein: 5. The disk drive according to claim 3, further comprising an operation unit for operating the operation of the initial adjustment unit. 6. The disk device according to claim 3, wherein the operation of the initial adjustment means is automatically started when the disk medium is mounted on a disk device main body. 7. An apparatus according to claim 1, further comprising an analog equalizer for performing a waveform equalization process on the reproduced signal in an analog manner, between the signal reproducer and the digital equalizer. The disk device as described above.