JP3495005B2 - Disc reproducing method and disc reproducing apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk reproducing method and a disk reproducing apparatus for a disk including a defect.

[0002]

2. Description of the Related Art A conventional disc reproducing apparatus is disclosed in Japanese Patent Laid-Open No. 61-34-61 when reproducing a disc containing defects such as scratches and fingerprints.
As shown in "Digital Disc Player" in Japanese Patent No. 735, a method of holding a tracking servo and a focus servo according to a defect detection result due to a level change of a disc reproduction signal, and "Disk drive" in Japanese Patent Laid-Open No. 4-268267. As shown in "Device", when the disc is defective, the pickup is moved to a position where there is no scratch, and tracking servo and focus servo are adjusted, and defect adaptive control is performed in tracking servo and focus servo. It is attempted to improve the reproducing ability of a disc including a defect.

Further, as shown in "Optical disc device" described in Japanese Patent Laid-Open No. 08-287623, when a disc is defective, the reproduction clock is set to an optimum frequency in binarizing the disc reproduction signal and clock reproduction. By performing the defect adaptive control such as holding, the reproduction capability of a disc including a defect is improved.

[0004]

However, when reproducing a defective disk, defect adaptive control in tracking servo and focus servo, and defect adaptive control in binarization and clock reproduction of an RF signal reproduced from the disk are performed. If this is done, the synchronization between the frame reproduced from the disk and the channel clock is lost, so even if demodulation-capable modulation data is input to the demodulation means, the modulation data until the correct synchronization pattern is detected is demodulated. It had a problem that it could not.

Therefore, even if defect adaptive control in tracking servo and focus servo, and defect adaptive control in binarization of an RF signal reproduced from a disk and channel clock reproduction are performed, the demodulation capability of the data demodulating means causes It had a problem that the effect was limited.

The present invention has been made in view of the above problems. Even when the synchronization between the frame reproduced from the disc and the channel clock is lost, input is performed before a normal synchronization pattern is detected. It is an object of the present invention to provide a disc reproducing device that enables demodulated demodulated modulated data and can minimize the non-demodulatable region.

[0007]

In order to solve the above-mentioned problems, the disk reproducing method according to claim 1 of the present invention is a disk reproducing method for reproducing a disk in which a plurality of frames are recorded. A sync generation step of detecting and interpolating a sync pattern of the issued frame and generating a sync signal, and calculating a DSV for each frame
However, the calculation result of the frame DSV exceeds the predetermined threshold.
If this happens, the frame is detected as a defective frame.
A defect detection step that, at least, a defect signal generating step of generating a defect signal based on the defect information detected by the defect detection step, the number of defects consecutive frames based on the defect signal generated by the defect signal generating step
Calculating and storing the number of defective frames, storing the frame read from the disk in a temporary storage memory, controlling the memory access, synchronizing signal generated by the synchronization generating step, and storing the number of defective frames A read position search step of detecting a read position of the frame stored in the temporary storage memory based on the number of consecutive defective frames stored in step; and data from the read position detected by the read position search step. A read step of reading from the temporary storage memory, a frame read from the disk, and a frame read from the temporary storage memory are demodulated, and demodulated data is output together with a signal indicating which frame is demodulated. By the demodulation step and the demodulation step Based on the adjusted data, and a signal indicating whether the demodulated any frame, is characterized in that and a demodulated data control step of generating demodulated data to be reproduced.

Further, in the disc reproducing method according to claim 2 of the present invention, a disc in which a plurality of frames are recorded
In the disc playback method for playing
Detects and interpolates the sync pattern of the projected frame,
A synchronization generation step for generating a synchronization signal;
Calculate the number of modulation data that cannot be demodulated, and demodulate the frame
When the number of impossible modulation data exceeds a predetermined threshold
Is a defect detection that detects the frame as a defective frame.
Detection step and at least the defect detection step.
A defect signal that generates a defect signal based on the issued defect information
Generated by the generation step and the defect signal generation step
Calculate the number of consecutive defective frames based on the generated defect signal
To store the number of defective frames
A frame that stores the frame read from the temporary storage memory.
Memory access control step and the synchronization generation step
Sync signal generated by the above, and storage of the number of defective frames
Based on the number of consecutive defective frames stored in step
Then, read the frame stored in the temporary memory.
A read-out position searching step for detecting the starting position;
Read position detected by the read position search step
Read from the temporary storage memory
Eject step and frame read from disc
And the frame read from the temporary storage memory
Demodulated, with a signal indicating which frame was demodulated
Demodulation step of outputting demodulation data to the
Data and any frame
Demodulated data that is played back based on the signal that indicates whether
And a demodulation data control step for generating .

Further, a disc reproducing method according to a third aspect of the present invention is the disc reproducing method according to the first or second aspect , wherein the read position searching step is the same as the above.
That a normal sync signal is input in the step generation step
The demodulated data control step is performed by
The frame read from the temporary storage memory during the adjustment step.
If the demodulated data of the system is output,
The demodulated data of the frame read from the disk
It is characterized by replacement .

According to a fourth aspect of the present invention, there is provided a disc reproducing method according to the first or second aspect , wherein the memory access control step is
Of the frames read from the disk
Only the judged frame is stored in the temporary storage memory .

According to a fifth aspect of the present invention, there is provided a disc reproducing method according to the first or second aspect , wherein the demodulating step is performed by always reading from the disc.
The extracted frame is being demodulated, and the temporary memory memo
When demodulating a frame stored in
The feature is that two demodulation operations are performed in parallel .

Further, a disc reproducing method according to a sixth aspect of the present invention is the disc reproducing method according to the first or second aspect , wherein the predetermined threshold value can be arbitrarily changed.
It is characterized by that.

According to a seventh aspect of the present invention, in the disc reproducing method according to the first or second aspect , only the modulated data read from the disc is used.
It is characterized in that it can be switched to a demodulation mode for demodulating .

Further, the disk reproducing apparatus according to claim 8 of the present invention is a disk in which a plurality of frames are recorded.
In a disc playback device that plays back
Detects and interpolates the sync pattern of the projected frame,
Synchronization generating means for generating a synchronization signal, and for each frame
The DSV is calculated, and the DSV calculation result of the frame is given
If the threshold of
Defect detecting means for detecting as
Generates a defect signal based on the defect information detected by the detection means.
And a defect signal generating means for generating the defect signal.
The number of consecutive defective frames based on the defect signal generated by
Disk for storing and storing the number of defective frames to be calculated and stored
Memory for storing frames read from
And temporarily store the frame read from the disk
Memory access control means for storing in the memory, and the synchronous generation
The sync signal detected by the means and the defective frame
The number of consecutive defective frames stored in the number storage means
Based on the reading of the frame stored in the temporary storage memory,
A reading position searching means for detecting the protruding position;
From the read position detected by the protruding position search circuit
Reading data from the temporary storage memory
Stage, the frame read from the disc, and the temporary
The frame read from the storage memory is demodulated and
Demodulated data with a signal indicating whether the frame of
And a demodulation means for outputting
Data and a signal that indicates which frame was demodulated
Demodulation data to generate demodulation data to be reproduced based on
And a control means .

According to a ninth aspect of the present invention, there is provided a disc reproducing device which reproduces a disc having a plurality of frames recorded therein. The disc reproducing device detects and interpolates a synchronization pattern of a frame read from the disc. , A synchronization generating means for generating a synchronization signal and a recovery unit for each frame.
Calculate the number of modulated data that cannot be adjusted, and cannot demodulate the frame
If the number of modulation data that can be
Defect detecting means for detecting the frame as a defective frame
And at least the defect information detected by the defect detection means.
Defect signal generating means for generating a defect signal based on the report,
Based on the defect signal generated by the defect signal generating means
Defect frame that calculates and stores the number of consecutive defective frames
Frame number storage means and the frames read from the disc
A temporary storage memory for storing, a memory access control means for storing the frame read from the disk in the temporary storage memory, and a synchronization signal detected by the synchronization generating means.
And the number of defective frames stored by the defective frame number storage means.
The temporary memory memo is based on the number of consecutive defective frames.
Read to detect the read position of the frame stored in the memory
Position search means and the read position search circuit.
The data from the read out position is temporarily stored in the memory.
Read from the disk and read from the disk
Selected frames and read from the temporary storage memory
And demodulates which frame was demodulated.
A demodulation means for outputting demodulated data together with the signal,
Data demodulated by the demodulation means and any frame
Demodulation data that is reproduced based on the signal that indicates whether
And demodulation data control means for generating data .

Further, a synchronization generating device according to a tenth aspect of the present invention is the disk reproducing device according to the eighth or ninth aspect.
In the reading position searching means,
Operates when a normal sync signal is input from the
However, the demodulation data control means is controlled by the demodulation means.
The demodulated data of the frame read from the time storage memory
If output, read the demodulated data from the disc.
It is characterized in that it is replaced with the demodulated data of the frame that is found.

Further, the synchronization generation device according to claim 11 of the present invention is the disk reproduction device according to claim 8 or 9.
In, the memory access control means is a disk
Of the frames read from the
It is characterized in that only the frames are stored in the temporary storage memory .

The synchronization generation apparatus according to claim 12 of the present invention is the disk reproduction apparatus according to claim 8 or 9.
, The demodulation means always read from the disc.
Are being demodulated and stored in the temporary storage memory.
When demodulating the stored frame,
It is characterized in that the demodulation operation is performed in parallel .

A disc reproducing apparatus according to a thirteenth aspect of the present invention is the disc reproducing apparatus according to the eighth or ninth aspect.
In the reproducing device, the predetermined threshold is an external control means.
It is characterized by being more changeable .

A disc reproducing apparatus according to a fourteenth aspect of the present invention is the disc reproducing apparatus according to the eighth or ninth aspect , in which the modulated data read from the disc is read.
It is characterized in that it can be switched to a demodulation mode for demodulating only one.

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION (Embodiment 1) A disk reproducing method and a disk reproducing apparatus of the present invention will be described below with reference to FIGS. 1 to 5. FIG. 1 is a block diagram showing an example of the configuration of a disc reproducing apparatus according to the first embodiment of the present invention.

In FIG. 1, 101 is a modulated data string having a synchronization pattern as a head (hereinafter referred to as a frame).
Is a synchronization generation circuit that generates a synchronization signal 113 that is a reference signal for demodulating the modulation data 111 that is composed of, and, if a normal synchronization pattern included in the modulation data 111 can be detected, the synchronization pattern is detected. Thus, the normal synchronization signal is generated and output, and when the normal synchronization pattern cannot be generated, the synchronization signal that interpolates the normal synchronization signal is generated and output. Further, when the synchronization generation circuit 101 outputs a synchronization signal that interpolates a normal synchronization signal and then outputs a normal synchronization signal, the synchronization generation circuit 101 should re-demodulate the modulated data until the normal synchronization signal is detected. , And outputs the operation instruction signal 123 to the read position search circuit 107.

Reference numeral 102 is a defect detection circuit which detects the physical defect contained on the disk by monitoring the input modulation data 111 and outputs it as a defect detection signal 114. 103 indicates that the data cannot be accurately demodulated from the defect detection signal 114 output from the defect detection circuit 102 and the defect information 112 detected by an external means such as a tracking servo or a focus servo. It is a defect signal generation circuit for generating the defect signal 115 shown.

A memory access control circuit 104 outputs a memory access control signal 116 for storing the input modulated data 111 in the temporary storage memory 105. The memory access control signal 116 is composed of, for example, modulation data to be stored and a storage address. Reference numeral 105 denotes a temporary storage memory that stores the modulation data output from the memory access control circuit.

When the defect signal 115 indicates that the modulated data 111 in the frame includes a defect, the frame 106 receives the synchronization signal 113 and the defect signal 115 as an input and determines the frame as a defective frame. This is a defective frame number storage circuit that counts up the number of detected defective frames and stores the count value until a frame that does not have is detected.

The memory access control circuit 107 operates when receiving the operation instruction signal 123 from the synchronization generation circuit 101, and outputs the memory access control signal 116 from the memory access control circuit 104.
Based on the number of defective frames 118 output from the defective frame number storage circuit 106, the read position of the modulation data stored in the temporary storage memory 105 is searched, and the read position instruction signal 119 is output to the read determination circuit 108. This is a read position search circuit. 108 generates the memory read control signal 117 according to the read position instruction signal 119, thereby reading the data from the read position indicated by the read position instruction signal 117 from the temporary storage memory 105, and the memory storage data 120.
Is a read circuit for outputting to the demodulation circuit 109 as.

A demodulation circuit 109 demodulates the input modulation data 111 and, when the memory storage data 120 is output from the reading circuit 108, demodulates the memory storage data 120 and outputs the demodulation data. At this time, the demodulated demodulated data 121 is output together with the demodulated data 121 and the data selection instruction signal 122 for instructing whether the demodulated data 121 or the memory storage data 120 is demodulated.

Reference numeral 110 denotes a demodulation data control circuit which has a buffer memory and controls the data stored in the buffer memory based on the demodulation data 121 demodulated by the demodulation circuit 109 and the data selection instruction signal 122. Is.

Next, the operation of the disc reproducing apparatus according to the first embodiment of the present invention will be described. Synchronization generation circuit 10
Reference numeral 1 is a sync signal 113 which is a reference signal for demodulating the modulated data 111 divided into units called frames.
In order to generate, the sync pattern included in the modulation data 111 is detected, and a normal sync signal is generated and output. When the normal synchronization pattern cannot be generated, the synchronization generation circuit 101 generates and outputs a synchronization signal that interpolates the normal synchronization signal. That is, when the sync pattern included in the modulation data 111 is broken, the sync signal 11 is generated at the position where the sync pattern should be included.
3 is interpolated, and when it is detected at a position where the sync pattern should not be included, generation of the sync signal 113 for the sync pattern is suppressed.

The sync signal 113 generated by the sync generation circuit 101 in this way is the defect detection circuit 102, the defective frame number storage circuit 106, and the read position search circuit 1.
07 and the demodulation circuit 109. Further, when the synchronization generation circuit 101 outputs a synchronization signal that interpolates a normal synchronization signal and then outputs a normal synchronization signal, the synchronization generation circuit 101 should re-demodulate the modulated data until the normal synchronization signal is detected. , The operation instruction signal 12 to the read position search circuit 107.
3 is output.

Upon receiving the synchronization signal 113, the defect detection circuit 102 detects a defect included in the modulation data 111 by monitoring the input state of the modulation data 111,
The defect detection signal 114 is generated. Then, the generated defect detection signal 114 is output to the defect signal generation circuit 103.

An example of a method of detecting defects contained in the modulation data 111 by the defect detection circuit 102 will be described below. In the first embodiment of the present invention, two methods described below will be described as a method of detecting a defect included in the modulation data 111 by the defect detection circuit 102.

First, the defect detection method included in the first modulation data 111 is performed by the DS of the modulation data 111 for each frame.
It is a method to calculate V (Digital Sum Variation),
It is recognized as a defect when the DSV calculation result for each frame exceeds a defect threshold value (a defect threshold value can be set by an external control unit such as a microcomputer) provided for recognizing a defect. This processing is illustrated in FIG. 3, in which the DSV is cleared by the synchronization signal and the calculation of the DSV is started.
If the DSV calculation result exceeds the defect threshold,
A defect detection signal is generated. The sync signal, the modulation data, and the defect detection signal in FIG. 3 are equivalent to the sync signal 113, the modulation data 111, and the defect detection signal 114 in FIG. 1, respectively.

Next, the defect detection method included in the second modulation data 111 is a method of counting the number of non-demodulatable data of the modulation data 111 for each frame. A defect is recognized when it exceeds a defect threshold provided for recognizing a defect (the defect threshold can be set by an external control unit such as a microcomputer). This processing is illustrated in FIG. 4, in which the number of non-demodulatable data is cleared by the synchronization signal, and counting of the number of non-demodulatable data is started. A defect detection signal is generated when the number of data that cannot be demodulated exceeds the defect threshold value.
The synchronization signal, the modulation data, and the defect detection signal shown in FIG.
Sync signal 113, modulation data 111, and
It is equivalent to the defect detection signal 114.

Next, the defect signal generation circuit 103 uses the defect information 112 detected by external means such as tracking servo and focus servo and the defect detection signal 114 output from the defect detection circuit 102 to perform external control of a microcomputer or the like. According to the condition designated by the means, a defect signal 115 indicating that the data cannot be demodulated accurately is generated. The generated defect signal 115 corresponds to the synchronization generation circuit 101 and the defective frame number storage circuit 106.
Output to.

The memory access control circuit 104 controls to store the modulation data 111 in the temporary storage memory 105, that is, converts the input modulation data 111 into a data format that can be stored in the temporary storage memory 105, and the converted data. To generate an address for storing in the temporary storage memory. The conversion data and the storage address generated here are output as a memory access control signal 116 to the temporary storage memory 105.

Upon receiving the memory access control signal 116, the temporary storage memory 105 receives the memory access control signal 1
The conversion data included in 16 is stored in the area indicated by the storage address.

Next, the defective frame number storage circuit 106
The synchronization signal 113 and the defect signal 115 are input, and the defect signal 11 is supplied for each frame indicated by the synchronization signal 113.
Monitor 5. That is, when the defective signal 115 indicates that the modulated data 111 in the frame includes a defect, the frame is counted as a defective frame. The count value counts up the number of defective frames and stores the count value until a frame having no defect is detected.

On the other hand, when the defective signal 115 indicates that the modulated data 111 in the frame does not include a defect, it is determined that the frame is a frame having no defect and the count value of the defective frame is reset. To do. The number of defective frames stored here is output to the read position search circuit 107 as the number of defective frames 118.

The read position search circuit 107 operates when receiving the operation instruction signal 123 from the synchronization generation circuit 101,
The data of the modulation data 111 stored in the temporary storage memory 105 in order to demodulate the data of the frame before the normal synchronization signal by inputting the synchronization signal 113, the memory access control signal 116, and the defective frame number 118. Determine the read position.

Specifically, the read position search circuit 107
Holds the storage address of the data included in the memory access control signal 116 and the number of read frames that can be arbitrarily set in advance. Then, the synchronization generation circuit 101
When receiving the operation instruction signal 123 from the read position search circuit 107, the read position search circuit 107 selects a frame before the number of frames held by the read position search circuit 107 from the frame indicated by the normal synchronization signal 113 output from the synchronization generation circuit 101. In order to read from the temporary storage memory 105, the frame start position before the number of frames held by the read position search circuit 107 is specified, and the read instruction signal 119 is generated based on the storage address of the stored data.

At this time, the read position search circuit 107
If the preset number of frames to be read out is larger than the number of defective frames output from the defective frame number storage circuit 106, the defective frame is changed to the preset number of read frames. The data of the number of defective frames output from the number storage circuit 106 is read.

By doing so, the number of frames read from the temporary storage memory 105 and decoded can be reduced, the processing speed can be improved, and the power consumption can be reduced.

Next, the read determination circuit 108 that has received the read instruction signal 119 generates the memory read control signal 117 based on the frame read instruction signal 119 to obtain the data of the frame stored in the temporary storage memory 105. The data of the read frame is output as the memory storage data 120 to the demodulation circuit 109.

The demodulation circuit 109 demodulates the input modulated data 111 and, when the memory storage data 120 is input from the read determination circuit 108, demodulates the memory storage data 120. In addition, the demodulation circuit 10
When the demodulated data 121, which is the demodulated data, is outputted, the demodulated data 121 is the demodulated modulated data 111 or the memory-stored data 120 is demodulated. A data selection instruction signal 122 indicating that is output.

In order to improve the processing speed, the demodulation circuit 109 sends the memory storage data 1 from the read determination circuit 108.
When 20 is input, demodulation of the modulated data 111,
And the memory storage data 120 are simultaneously demodulated in parallel.

The demodulated data control means 110 sequentially stores the demodulated data 121 corresponding to the input modulated data 111 in the buffer memory of the data reproduction control means 110 and demodulates the memory stored data 120 from the demodulation circuit 109. When the demodulation data 121 with the data selection instruction signal 122 indicating is output, the demodulation data obtained by demodulating the modulation data 111 at the corresponding data position where the demodulated data is stored in the buffer memory. Replace with.

Next, the operation of the disc reproducing apparatus according to the first embodiment of the present invention will be specifically described with reference to FIGS. FIG. 5 is an explanatory diagram for specifically explaining the operation of the disc reproducing apparatus. In FIG. 5, the synchronization signal indicates the synchronization signal 113 generated by the synchronization generation circuit 101, and the modulation data indicates the disc. The modulated data 111 and the demodulated data (real-time data) input to the reproducing apparatus indicate demodulated data 121 obtained by demodulating the modulated data 111, and the demodulated data (temporary storage data) indicate the demodulated data 121 obtained by demodulating the memory storage data 120, respectively. The temporary storage memory is equivalent to the temporary storage memory 105 in FIG. 1, and the buffer memory is the demodulated data reproduction control means 1
10 is a buffer memory which stores data to be reproduced.

When the modulation data n, n + 1, ... Shown in FIG. 5 is input to the disc reproducing apparatus as the modulation data, the input modulation data demodulates the modulation data input by the demodulation circuit 109 (real-time data). At the same time
The memory access control circuit stores the input modulated data in the temporary storage memory. The modulated data demodulated by the demodulation circuit 109 is demodulated data (real-time data).
It is output to the demodulation data control circuit 110 as n ′, n + 1 ′, ... And stored in the buffer memory 301 of the demodulation data control circuit 110.

Here, when the demodulated data (real-time data) has a defective area shown in FIG. 5, there is a possibility that an abnormality occurs in the channel clock in the defective portion of the modulated data and a synchronization shift occurs. Therefore, the demodulation data (n ′ to n + 3 ′) until the normal synchronization signal included in the modulation data is detected may have an error.

Therefore, when the modulated data input to the disc reproducing device is defective, the sync position generating circuit 101 detects a normal sync pattern, whereby the read position searching circuit 107 operates and the temporary storage memory 105 stores it. Instruct to read the stored defective modulation data.

That is, in FIG. 5, when the read position search circuit 107 is set in advance so as to read data for one frame from the temporary storage memory 105, the read position search circuit 107 performs normal synchronization. After the signal (sync pulse located at the head of n + 4) is input, the read circuit 108 is instructed to read the data (n + 3) for one frame before the position where the normal sync signal is input.

At this time, the defective frame number storage circuit 1
The defective frame number 118 output from 06 is 4 (n to 4) as the defective frame number 118 because the defective frame number 118 is output up to the time point when the normal synchronizing signal (the synchronizing pulse located at the head of n + 4) is generated. 4) (n + 3) are output. Therefore, since the number of defective frames is larger than the number of frames to be read, the read position search circuit 107 outputs an instruction to read data for one predetermined frame.

Then, the data (n + 3) is read from the temporary storage memory 105 and demodulated by the demodulation means 109. The data demodulated here is demodulation (temporary storage data) n + 3 ″, and the demodulation data control circuit 1
By 10, the demodulated data (real-time data) n + 3 ′ stored in the buffer memory is overwritten.

Since the demodulated data can accurately grasp the sync pattern storage position of the data stored in the temporary storage memory on the basis of the normal sync pattern included in the modulated data, the demodulated data is included in the input modulated data 111. , Data that can be demodulated are faithfully demodulated.

As described above, by replacing the demodulation data (real-time data) which may be erroneous with the demodulation data (temporary storage data) that is faithful to the input modulation data, the disc reproduction including the physical defect is reproduced. In, it is possible to minimize the non-demodulatable area of the input modulation data.

The number of frames of modulated data that can be stored in the temporary storage memory 105 is not described, but due to the limitation of the memory capacity of the temporary storage memory 105,
When only a fixed number of frames can be stored in the temporary storage memory 105, the number of frames to be read, which is instructed by the read position search circuit 119, can be controlled to be equal to or less than the number of frames stored in the temporary storage memory 105. In this case, the same effect of the present invention can be obtained.

Further, the memory access control circuit 104 is
The defect signal 115 may be input from the defect signal generation circuit 103, and the memory access control circuit 104 may store only the defective modulation data in the temporary storage memory 105. In this case, the temporary storage memory The storage area of can be effectively used.

The read position search circuit 107 has been described as generating the read instruction signal 119 so as to read the data for each frame stored in the temporary storage memory 105.
For example, 7 may generate the read instruction signal 119 so as to read data from an arbitrary position in the frame.

Further, the demodulation method of the disc reproducing apparatus described in the first embodiment of the present invention and the demodulation mode for demodulating only the modulated data 111 read from the disc are switched to perform the demodulation processing. In this case, the demodulation method can be switched according to the demand for high speed and certainty of data reproduction.

(Second Embodiment) A disk reproducing apparatus according to a second embodiment of the present invention will be described below. The disc reproducing apparatus according to the second embodiment of the present invention is
This is a modification of the sync generation circuit 101 of the disc reproducing apparatus according to the first embodiment, which generates a more accurate sync signal even if the modulated data 111 has a defect and improves the demodulating ability of the disc reproducing apparatus. It is intended to improve.

The synchronization generating circuit of the disc reproducing apparatus according to the second embodiment of the present invention will be described below in more detail with reference to FIG. FIG. 2 is a diagram showing an example of the configuration of the synchronization signal generation circuit 101 of the disc reproducing apparatus according to the second embodiment of the present invention. The modulation data 212, the synchronization signal 221, and the defect signal 211 of FIG. Figure 1
Of the channel clock 213, which is equivalent to the modulated data 111, the synchronization signal 113, and the defect signal 115 of FIG.
Indicates a clock extracted from a frame read from the disc, and a system clock 214 indicates a clock having a constant frequency for managing the entire disc reproducing apparatus. Each component other than the synchronization generation circuit 101 of the disc reproducing apparatus according to the second embodiment of the present invention is the same as the disc reproducing apparatus shown in FIG. 1 (not shown), and in FIG. Clock 213,
The system clock 214 is not shown because the drawing is complicated, but these clock signals are input to each component as a timing signal for controlling the operation of the disc reproducing apparatus.

In FIG. 2, reference numeral 201 denotes a sync detection window 216 indicating a range for detecting a sync pattern to detect the sync pattern, or a channel clock 213 synchronized with the modulation data 212 to complement the sync pattern. , A synchronization detection / interpolation circuit for generating a capacitance component synchronization signal 215.

Reference numeral 202 denotes a channel clock counter which counts the channel clock 213 based on the capacitance component synchronizing signal 215 and outputs a channel clock count value 217. Reference numeral 203 is a system clock counter that counts the system clock 214 having a constant frequency based on the capacitance component synchronization signal 215 and outputs a system clock count value 218.

Reference numeral 204 denotes a sync interval measuring circuit which converts the interval of the capacitive component sync signal 215 into a system clock count value 218 and outputs a sync time interval signal 219.
Reference numeral 205 denotes a sync detection window generation circuit that outputs a sync detection window 216 indicating a range in which the sync pattern is detected from the modulated data 212. Reference numeral 206 denotes a pseudo sync generation circuit for generating a sync signal in the defective area and generating a time component sync signal 220 using the sync time interval signal 219. 207 is a capacitance component synchronization signal 215 output from the synchronization detection / interpolation circuit 201,
And a synchronization signal generation circuit that outputs a synchronization signal 221 based on the time component synchronization signal 220 output from the pseudo synchronization generation circuit 206.

Next, the operation of the synchronization generating circuit 101 thus configured will be described below. The synchronization detection / interpolation circuit 201 generates a capacitance component synchronization signal 215 when the input defect signal 211 does not indicate that the modulation data 212 is defective, and is indicated by the input synchronization detection window 216. Modulation data 21 in the area
If the sync pattern included in 2 can be detected, the sync pattern is detected and the capacitive component sync signal 2 is detected.
When the sync pattern is not detected within the area indicated by the sync detection window 216,
By interpolating the synchronization, the capacitive component synchronization signal 215
To generate.

On the other hand, when the input defect signal 211 indicates that the modulation data 212 has a defect, the synchronization detection / interpolation circuit 201 stops the synchronization detection / interpolation process,
The capacitive component synchronizing signal 215 is not generated. The capacitance component synchronization signal 215 thus generated is used as the channel clock counter 202, the system clock counter 203, the synchronization interval measurement circuit 204, the pseudo synchronization generation circuit 206, and
It is output to the synchronization signal generation circuit 207.

The channel clock counter 202 which has received the capacitance component synchronization signal 215 receives the capacitance component synchronization signal 21.
The channel clock is counted at each synchronization interval of 5,
The count result is output as the channel clock count value 217. This channel clock count value 2
Reference numeral 17 denotes the data capacity input from the modulated data 212 with the capacity component synchronization signal 215 as a reference.

The channel clock count value 217 counted by the channel clock counter 202 is output to the synchronization detection window generation circuit 205.

Upon receiving the channel clock count value 217, the synchronization window generation circuit 205 monitors the position of the synchronization pattern included in the modulated data 212 by comparing the data capacity of the frame with the channel clock count value 217, and performs synchronization. Generate a detection window 216. The synchronization detection window 216 rises before several channel clocks (the number of channel clocks can be set by an external control means such as a microcomputer) from the position of the synchronization pattern included in the modulated data 212, and the synchronization pattern is detected or predetermined. Of the synchronization detection window length (this synchronization detection window length can be set by an external control unit such as a microcomputer) and is output to the synchronization detection / interpolation circuit 201.

On the other hand, the system clock counter 203 which has received the capacitance component synchronizing signal 215 counts the system clock, and the count result is set to the system clock count value 21 every time the capacitance component synchronizing signal 215 is input.
The value is output as 8, and the counter value of the system clock counter 202 is reset. The system clock count value 218 indicates the time input from the modulation data 212 with the capacitive component synchronization signal 215 as a reference because the system clock has a constant frequency. The system clock count value 218 is output to the synchronization interval measurement circuit 204 and the pseudo synchronization generation circuit 206.

The synchronization interval measuring circuit 204, which has received the capacitance component synchronization signal 215 and the system clock count value 218, generates the capacitance component when the modulated data 212 output from the synchronization detection / complementation circuit 201 has no defect. By monitoring the system clock count value 218 for each synchronization signal 215, the synchronization interval, ie, 1
The frame time can be measured, and the sync time interval signal 219, which is the measured sync interval, is output to the pseudo sync signal generation circuit 206.

The pseudo sync generation circuit 206 which has received the system clock count value 218 and the sync time interval signal 219 detects that the modulation component 212 contains a defect, that is, the capacitance component sync signal 215 in the sync detection / interpolation circuit 201. The time component synchronization signal 2 is operated by operating when not generated and interpolating and generating the synchronization signal not generated by the capacitance component synchronization signal 215 based on the system clock count value 218 and the synchronization time interval signal 219.
20 and outputs it to the synchronization signal generation circuit 207.

Further, when the pseudo sync signal generation circuit 206 outputs the time component sync signal 220 to the sync signal generation circuit 207, it resets the counter value of the channel clock counter 202. This is a scratch on the disc,
This is because the frequency of the channel clock input to the channel clock counter 202 may be abnormal due to a defective area such as a fingerprint.

A synchronization signal generation circuit 207 which has received the capacitance component synchronization signal 215 and the synchronization time interval signal 219.
When the defective area 211 indicates that the modulated data 212 has no defect, the capacitive component synchronizing signal 215 is set to the synchronizing signal 2
21 and the defective area 211 is modulated data 212.
, The sync time interval signal 21
9 is output as the synchronization signal 221.

The synchronization signal 221 generated by the synchronization signal generation circuit 207 of the synchronization generation circuit in this manner is as shown in FIG.
In the defect detection circuit 102, defective frame number storage circuit 106, read position search circuit 107, and demodulation circuit 109. Further, the synchronization signal generation circuit 207 of the synchronization generation circuit detects the normal synchronization signal after outputting the synchronization signal that interpolates the normal synchronization signal,
An operation instruction signal 123 is output to the read position search circuit 107 to demodulate the modulated data until the normal synchronization signal is detected.

The normal sync signal referred to here is
In the case where the defective area 211 indicates that the modulated data 212 has no defect, it means a sync signal generated based on the sync pattern detected in the area indicated by the sync detection window 216, and is a normal sync signal. The synchronization signal for interpolating is a synchronization signal other than the normal synchronization signal.

As described above, in the second embodiment of the present invention,
If the modulated data 212 has no defect, a generally used synchronization signal is generated using a channel clock,
When the modulated data 212 has a defect, the frequency may be abnormal because the frequency may be abnormal due to the influence of defects such as scratches and fingerprints on the disk. By generating the synchronization signal using the constant system clock, it is possible to provide a synchronization generation circuit that can accurately generate the synchronization signal even if the modulation data 212 has a defect.

Further, since the count point in the system clock counter 203 is increased by increasing the frequency of the system clock input to the system clock counter 203, the time component synchronization signal 220 generated in the pseudo synchronization generation circuit 206 is changed. It can be generated more accurately.

(Third Embodiment) A disk reproducing method and a disk reproducing apparatus according to a third embodiment of the present invention will be described below with reference to FIGS. 6 and 7. The disc reproducing apparatus according to the third embodiment of the present invention stores all the input modulation data 611 in the temporary storage memory, and always reads the data of a plurality of frames before the frame in which the synchronization signal is generated from the temporary storage memory. The point of demodulation is different from that of the first embodiment in that the data before the frame in which the synchronization signal is generated is read out and demodulated only when the defective frame exists.

In FIG. 6, reference numeral 601 denotes a modulated data string having a synchronization pattern as a head (hereinafter referred to as a frame).
Is a synchronization generation circuit for generating a synchronization signal 601 which is a reference signal for demodulating the modulated data 611 consisting of

Reference numeral 602 denotes a memory access control circuit which outputs a memory access control signal 613 for storing the input modulation data 601 in the temporary storage memory 603. The memory access control signal 613 includes, for example, the modulation data to be stored and the storage address. Reference numeral 603 is a temporary storage memory that stores the modulation data output from the memory access control circuit.

Reference numeral 604 denotes a sync signal 612 output from the sync generation circuit 601 and the memory access control circuit 60.
The memory read control signal 614 is generated and read based on the memory access control signal 613 output from No. 2 in order to read the data which is set a predetermined number of frames before the frame indicated by the synchronization signal. A read circuit that outputs data to the demodulation circuit 605 as memory storage data 615.

Reference numeral 605 demodulates the memory storage data 615 output from the reading circuit 604 to obtain the demodulation data 61.
6 is a demodulation circuit that outputs 6.

Next, the operation of the disc reproducing apparatus according to the first embodiment of the present invention will be described with reference to FIGS. 6 and 7. FIG. 7 is an explanatory diagram for specifically explaining the operation of the disc reproducing apparatus. In FIG. 7, the synchronization signal indicates the synchronization signal 612 generated by the synchronization generation circuit 611, and the modulation data indicates the disc. The modulation data 611 and the demodulation data (temporary storage data) input to the reproducing apparatus indicate demodulation data 616 obtained by demodulating the memory storage data 615. Further, the temporary storage memory is equivalent to the temporary storage memory 603 in FIG.

When the modulation data 611 is input to the disc reproducing apparatus as the modulation data 611 as shown in FIG. 7, the input modulation data 611 is stored in the temporary storage memory 603 by the memory access control circuit 602. Is stored.

Next, the read circuit 604 makes a memory access so as to read from the temporary storage memory 603 data from the frame indicated by the sync signal 612 output from the sync generation circuit 601 and having a predetermined number of frames before. Based on the memory access control signal 613 output from the control circuit 602, the storage address of the frame to be read is specified, and the data of the frame is read.

For example, in the case where the read circuit 604 is set to always read the data one frame before the frame indicated by the synchronization signal 612, for example, the read circuit 604 sets the beginning of the modulation data n + 4. When the synchronization signal shown in FIG. 3 is input, the memory read control signal 614 is generated so that the data n + 3, which is the data one frame before the modulation data n + 4, is read from the temporary storage memory 105, and the temporary storage memory 603 is generated.
Read data from.

Next, when the reading circuit 604 reads the data of the frame before the frame indicated by the synchronization signal 612 by a preset number of frames from the temporary storage memory 105, the demodulation circuit 615 outputs the memory storage data 615. Output to 605. The memory storage data 615 output to the demodulation circuit 605 is demodulated by the demodulation circuit 605 and demodulated data (temporary storage data) n− shown in FIG.
It is output as 1 ', n', n + 1 ', .... Note that the demodulation data 616 output from the demodulation circuit 605 is as shown in FIG.
It is stored in the buffer memory as shown in.

As described above, in the disc reproducing apparatus according to the third embodiment of the present invention, the modulation data 611 read from the disc is stored in the temporary storage memory 603, and at the time of demodulating the data, it is indicated by the generated synchronization signal 612. It is possible to demodulate the modulation data stored in the temporary storage memory based on the correctly detected sync signal by reading the data of the frame that is a predetermined number of frames before the current frame and demodulating it. Therefore, the non-demodulation area can be minimized.

Although the number of frames of modulated data that can be stored in the temporary storage memory 105 is not particularly described, due to the limitation of the memory capacity of the temporary storage memory 105,
When only a fixed number of frames can be stored in the temporary storage memory 105, the number of frames read by the reading circuit 604 may be controlled to be equal to or less than the number of frames stored in the temporary storage memory 603. In this case, the same effect as the present invention can be obtained.

Further, the read circuit 604 has been described as generating the memory read control signal 614 so as to read the data for each frame stored in the temporary storage memory 603. The memory read control signal 614 may be generated so as to read data from an arbitrary position therein.

[0103]

As described above, according to the disc reproducing method and the disc reproducing apparatus of the present invention, the modulation data read from the disc is stored in the temporary storage memory, and the correctly detected sync pattern is used as a reference. By demodulating the modulation data stored in the temporary storage memory, the modulation data and the channel clock are out of synchronization due to physical defects such as scratches and fingerprints contained on the disk, and the modulation data can be demodulated. Nevertheless, even if there is an area that cannot be demodulated (area from the physical defect to the sync pattern that can be detected), the area that can be demodulated can be demodulated, and the area that cannot be demodulated is minimized. Can be suppressed.

Further, by controlling so as to minimize the non-demodulatable area in this way, scratch adaptive control in tracking servo and focus servo, and binarization of the RF signal reproduced from the disk and channel clock reproduction are performed. Even when the wound adaptive control is performed, the effect of improving the reproduction ability of the wound adaptive control can be sufficiently obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a configuration of a disc reproducing device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an example of a configuration of a synchronization generation circuit of a disc reproducing device according to a second embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating an example of a defect detection method of the defect detection circuit according to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram illustrating an example of a defect detection method of the defect detection circuit according to the first embodiment of the present invention.

FIG. 5 is an explanatory diagram for explaining a specific operation of the disc reproducing device according to the first embodiment of the present invention.

FIG. 6 is a block diagram showing an example of a configuration of a disk reproducing device according to a third embodiment of the present invention.

FIG. 7 is an explanatory diagram for explaining a specific operation of the disc reproducing apparatus according to the third embodiment of the present invention.

[Explanation of symbols]

101, 601 synchronization generation circuit 102 defect detection circuit 103 defect signal generation circuit 104, 602 Memory access control circuit 105, 603 Temporary storage memory 106 defective frame number storage circuit 107 read position search circuit 108, 604 Read determination circuit 109,605 Demodulation circuit 111, 212, 611 Modulation data 112 Defect information 113,612 Sync signal 114 Defect detection signal 115, 211 Defect signal 116, 613 Memory access control signal 117, 614 Memory read control signal 118 number of defective frames 119 frame read instruction signal 120,615 Memory storage data 121,616 Demodulated data 122 Data selection instruction signal 201 Synchronization detection / interpolation circuit 202 channel clock counter 203 system clock counter 204 Sync interval measurement circuit 205 synchronization detection window generation circuit 206 Pseudo synchronization generation circuit 207 Synchronous signal generation circuit 213 channel clock 214 system clock 215 Capacitance component synchronization signal 216 Sync detection window 217 channel clock count value 218 System clock count value 219 Synchronous time interval signal 220 time component synchronization signal 221 Sync signal

Continuation of the front page (51) Int.Cl. ⁷ Identification code FI G11B 20/10 G11B 20/10 C 20/14 341 20/14 341B (72) Inventor Toru Aoki 1 of 8 Koshinmachi, Takamatsu-shi, Kagawa Matsushita Hisashi Electronic Industry Co., Ltd. (56) Reference JP-A-8-63904 (JP, A) JP-A-7-98944 (JP, A) JP-A-9-73737 (JP, A) (58) Fields investigated ( Int.Cl. ⁷ , DB name) G11B 20/10 G11B 20/14 G11B 20/18

Claims (14)

(57) [Claims] 1. A disc reproducing method for reproducing a disc in which a plurality of frames are recorded, wherein a synchronization generation step of detecting and interpolating a synchronization pattern of a frame read from the disc to generate a synchronization signal; Calculates the DSV for each and calculates the DSV of the frame
If the calculation result of exceeds the specified threshold,
Defect detection step of detecting the defect as a defect frame , at least a defect signal generation step of generating a defect signal based on the defect information detected in the defect detection step, the defect signal generated by the defect signal generation step A defective frame number storage step of calculating and storing the number of consecutive defective frames based on the above; a memory access control step of storing the frames read from the disk in a temporary storage memory; and a synchronization signal generated by the synchronization generation step. , And the consecutive number stored in the defective frame number storing step.
A read position search step of detecting a read position of a frame stored in the temporary storage memory based on the number of defective frames; and a read operation of reading data from the read position detected by the read position search step from the temporary storage memory. A demodulation step of demodulating a frame read from the disk and a frame read from the temporary storage memory, and outputting demodulated data together with a signal indicating which frame is demodulated; And a demodulation data control step of generating demodulation data for reproduction based on the data demodulated by the above and a signal indicating which frame is demodulated. 2. A disc having a plurality of frames recorded therein.
In the disc playback method that plays back, the sync pattern of the frame read from the disc is detected.
A synchronization generation step of outputting / interpolating and generating a synchronization signal, and calculating the number of modulation data that cannot be demodulated for each frame,
The number of modulated data that cannot be demodulated in a frame exceeds a predetermined threshold.
If it exceeds, the frame is detected as a defective frame.
Defect detection step to be issued, and at least the defect information detected in the defect detection step
A defect signal generation step for generating a defect signal based on
And the defect signal generated by the defect signal generation step
Based on the defect number, the number of consecutive defective frames is calculated and stored.
The frame number storage step and the frame read from the disc.
Memory access control to store ram into temporary memory
Graphics and steps, synchronizing signal generated by the synchronization generation step, and
The succession stored in the step of storing the number of defective frames
To the temporary memory based on the number of defective frames
Read position to detect the read position of the stored frame
A location search step, read out is detected by the reading position search step
Read data from the temporary location from the temporary storage memory
The reading step, the frame read from the disc, and the temporary storage memory.
The frame read from the memory is demodulated and any frame
Output demodulated data with a signal indicating whether the demodulated
The demodulation step for performing the demodulation step, the data demodulated by the demodulation step, and
Playback is performed based on the signal that indicates whether the frame has been demodulated.
A demodulation data control step for generating demodulation data.
Disk playback method characterized by comprising. 3. A disc reproducing method according to claim 1 or 2, wherein the reading position search step, the synchronization generation step
Operates by successful synchronization signal is inputted by the flop
However , the demodulation data control step is performed by the demodulation step.
Demodulation data of the frame read from the temporary storage memory.
If the demodulated data is output to a disk,
A disc reproducing method characterized by replacing the demodulated data of a frame read from the frame . 4. A disc reproducing method according to claim 1 or 2, wherein the memory access control step reads from disk
Of the transmitted frames, the frame judged to be defective is
A disk playback method characterized in that only the memory is stored in a temporary storage memory . 5. The disc reproducing method according to claim 1 or 2 , wherein the demodulating step is performed on a disc which is always read from the disc.
Is being demodulated and stored in the temporary storage memory
When demodulating an existing frame,
A disc playback method characterized by performing works in parallel . 6. The disc reproducing method according to claim 1 or 2 , wherein the predetermined threshold value can be arbitrarily changed . 7. The disc reproducing method according to claim 1 or 2 , wherein only the modulated data read from the disc is demodulated.
A disc playback method characterized by being able to switch to the key mode . 8. A disc in which a plurality of frames are recorded
In a disc playback device that plays back a disc, the sync pattern of the frame read from the disc is detected.
A synchronization generating means for outputting / interpolating and generating a synchronization signal, and calculating a DSV for each frame, and a DSV of the frame
If the calculation result of exceeds the specified threshold,
Defect detection means for detecting a frame as a defect frame, and at least the defect information detected by the defect detection means.
A defect signal generating means for generating a fault signal based on the basis of the defect signal generated by the defect signal generating means
Defect frame that calculates and stores the number of consecutive defective frames
Number storage means and temporary storage for storing the frames read from the disk
Memory and frames read from disk to temporary storage memory
A memory access control means for storing, a synchronization signal detected by the synchronization generation means, and the
The consecutive defects stored in the defective frame number storage means
Stored in the temporary storage memory based on the number of frames
Read-out position searcher that detects the read-out position of the frame
And the read position detected by the read position search circuit.
Read from the temporary storage memory
The output means, the frame read from the disc, and the temporary storage memory.
The frame read from the memory is demodulated and any frame
Output demodulated data with a signal indicating whether the demodulated
Demodulating means, the data demodulated by the demodulating means, and any frame
Playback based on a signal that indicates whether the
A disc reproducing apparatus comprising: demodulation data control means for generating key data . 9. A disc reproducing apparatus for reproducing a disc in which a plurality of frames are recorded, a synchronization generating means for detecting and interpolating a synchronization pattern of a frame read from the disc to generate a synchronization signal, and each frame. Calculate the number of modulated data that cannot be demodulated in
The number of modulated data that cannot be demodulated in a frame exceeds a predetermined threshold.
If it exceeds, the frame is detected as a defective frame.
Defect detection means to be output , and at least the defect information detected by the defect detection means
A defect signal generating means for generating a fault signal based on the basis of the defect signal generated by the defect signal generating means
Defect frame that calculates and stores the number of consecutive defective frames
Number storage means and temporary storage for storing the frames read from the disk
Memory and a memory access control means and the detected synchronization signal by the synchronization generation means for storing a frame read from the disk to the temporary storage memory, and the
The consecutive defects stored in the defective frame number storage means
Stored in the temporary storage memory based on the number of frames
Read-out position searcher that detects the read-out position of the frame
And the read position detected by the read position search circuit.
Read from the temporary storage memory
The output means, the frame read from the disc, and the temporary storage memory.
The frame read from the memory is demodulated and any frame
Output demodulated data with a signal indicating whether the demodulated
Demodulating means, the data demodulated by the demodulating means, and any frame
Playback based on a signal that indicates whether the
A disc reproducing apparatus comprising: a demodulation data control unit for generating key data . 10. The disk reproduction according to claim 8 or 9.
In the apparatus, the read position searching means is a unit that is directly connected to the synchronization generating means.
It operates by inputting a normal synchronizing signal, and the demodulation data control means temporarily stores the demodulation data control means.
Outputs the demodulated data of the frame read from the memory
Read the demodulated data from the disc,
A disc reproducing apparatus , characterized in that it is replaced with demodulated data of a generated frame . 11. The disc reproduction according to claim 8 or 9.
In the device , the memory access control means reads from the disk.
Frames that were judged to be defective
Di characterized by storing only the temporary storage memory
Disk reproducing device . 12. The disk reproduction according to claim 8 or 9.
In the device , the demodulation means always operates on the frame read from the disc.
Are being demodulated and stored in the temporary storage memory.
When demodulating a frame
A disc playback device characterized by being performed in parallel . 13. A disc reproducing apparatus according to claim 8 or 9 , wherein the predetermined threshold value can be changed by an external control means. Playback device. 14. A disc reproducing apparatus according to claim 8 or 9 , wherein only the modulated data read from the disc is demodulated.
A disc player that can be switched to the key mode .