JPH11273072A - Disk reproducing method and disk reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly perform a reading mode change caused by an unreadable error. SOLUTION: Firstly, a system controller 23 sets a disk motor 3 to a high- speed reading mode to rotate it at a high-speed, and outputs a control signal to a servo circuit 25 and a focus tracking servo circuit 31 to read a desired data of a disk 1 by a pickup 7. When an uncorrectable error occurs, the system controller 23 changes the reading mode of the disk motor 3 to a low-speed reading mode to rotate it at a low-speed, and controls to perform a retry operation to read the desired data again. When the desired data can be read by this retry operation, the system controller 23 judges whether or not the disk motor needs to be returned to the high-speed reading mode by a defect detection flag of defect judging circuit 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CD-ROM
The present invention relates to a disk reproducing method and a disk reproducing apparatus for reproducing an optical disk such as a VD.

[0002]

2. Description of the Related Art In recent years, a CD-ROM or DVD-ROM having a large data amount has been used for reproducing moving images. These disks are recorded at a constant storage density called CLV.

[0003] Data is read out by rotating these disks at high speed by a disk drive, that is, by so-called double speed reproduction, and movie software as a moving image is reproduced. In a disk reproducing apparatus for reproducing a disk recorded with such a CLV, the rotation speed of the disk motor is
It changes depending on the read track position in the disk radial direction so that the linear velocity becomes constant. This is called CLV reproduction.

In order to reduce the power consumption of the disk motor, a method of rotating a disk recorded at CLV at a constant speed is also used. This is called CAV reproduction. In this case, the reading speed is higher when the outer periphery of the disk is reproduced than when the inner periphery of the disk is reproduced.

[0005] In a so-called movie reproducing apparatus for reproducing moving images, speeding-up is effective. This is because a moving image at the time of fast forward playback or fast reverse playback can be smoothly played back.

In addition, high-speed reproduction can increase the amount of data per unit time that can be continuously read from a disk, and is effective in improving the utilization of a personal computer.

However, when trying to read data by rotating the disk at a high speed, Japanese Patent No. 25547 is used.
As described in detail in Japanese Patent No. 19, there is a problem that the reading ability is deteriorated. In particular, uncorrectable errors caused by scratches and dirt on the disk and defects on the disk itself can be improved by lowering the reproduction speed, that is, the rotation speed of the disk.

Optical media such as CD-ROMs and DVD-ROMs use a correction method that assumes errors due to scratches and dirt on the disk. A correction format is defined so that a CD uses an interleave method, and a DVD uses a block correction to perform a correction process using data of a period sufficiently longer than the duration of a scratch or dirt. However, the disk originally has defects at locations other than scratches and dirt. This occurs at the time of manufacturing a disc or recording in the case of a recording medium. Since the size of the defect is related to the correction as described above, the occurrence of the uncorrectable state changes depending on the reproduction speed.

The situation of occurrence of the uncorrectable condition becomes worse as the reproduction speed increases. There are two main reasons. One is
This is caused by the frequency characteristics of a head that picks up a disk signal or a photodetector that converts light into electricity, and the noise of an analog amplifier. The sensitivity of the photodetector decreases as the frequency increases. This is mainly due to the parasitic capacitance of the detector. Therefore, S / N
Worsens, and the error occurrence situation worsens. Further, in the amplifying unit, as the frequency increases, the noise increases, and the error occurrence situation worsens. In addition, the state of occurrence of an error is deteriorated by deterioration of jitter due to deterioration of high-frequency tracking performance of an auto slicer for absorbing amplitude fluctuation and DC fluctuation of an analog signal caused by fluctuation of a track on a disk.

[0010] The second problem is that the disk has runout and eccentricity. The cycle of the surface runout or eccentricity is synchronized with one rotation of the disk. Measures corresponding to these disk track swings are applied to the focus servo and tracking servo, but these actuators are generally performed by moving the objective lens, and there is a secondary resonance, It exists at about 10 kHz to 30 kHz. It is difficult to raise the resonance frequency more than this both costly and technically. Therefore, the servo band is
It is not possible to raise the disk without any restriction, and there is a limit to the magnitude of the track swing of the disk and the increase in the number of revolutions. In other words, the ability to be suppressed by the servo becomes more advantageous as the disk speed becomes lower, and the error caused by this becomes worse as the reproduction speed becomes higher. In addition, this leads to an increase in the speed and deterioration of the frequency component of the jitter fluctuation on the time axis, thereby deteriorating the error situation.

Particularly, in recent years, there is a problem of the eccentricity of the disk. This is 2 times the rotation speed of the disk.
Due to the vibration generated in proportion to the power, the servo capability becomes too large to cover. The effect of this is also reduced by reducing the rotation speed.

As described above, the use of the CAV method to suppress an increase in power consumption caused by acceleration and deceleration of the disk motor at the time of access has begun to be frequently used.
In this method using a CLV disk at almost constant rotation, the data speed differs between the inner circumference and the outer circumference of the disk. It is slow at the inner circumference of the disc and faster at the outer circumference. As an example, 12cmC
In the case of a D-ROM disk, if the data rate is 150 kbytes / second on the inner circumference, the data rate on the outer circumference is about 2.4 times that of 360 kbytes / second. In this case, the problem is that the reading speed is 2.4 times different between the inner circumference and the outer circumference of the disk, so that it is difficult to optimize the reading performance such as a defect. In particular, when the speed is increased, there is a problem of the frequency characteristics of the signal detection system. Digitally recorded signals include, for example, signals from 3T to 11T in the CD format. In order to read these signals with high accuracy, the group delay characteristic must be 3T.
This is because it is necessary to make T to 11T. In other words, CVL only needs to consider frequencies from 3T to 11T, but CAV needs to cover frequencies from 1.25T to 11T.

On the other hand, in the method in which the rotation of the disk is controlled by the CLV, the reading speed does not change between the inner circumference and the outer circumference of the disk. Therefore, it is easy to improve the group delay characteristic, and the reading performance of the disk can be improved. However, as you increase the rotation of the disk for higher speed,
The difference between the rotation speed on the inner circumference of the disk and the outer circumference speed increases,
This results in a disadvantage that the time required to change the number of revolutions is increased and the access time is increased. That is, when the access time is included, the CLV method is used in the low-speed mode, and the CAV method is used in the high-speed mode.
The V method is advantageous.

Therefore, in the conventional disk reproducing apparatus, usually, the disk motor is rotated in the high-speed read mode, the servo band is set to the corresponding servo band, and the pickup is moved to the disk radial position where desired data is recorded. , The desired data is being read. Whether the desired data has been read correctly can be determined based on error information of the correction block or a CRC (determination based on cyclic code) determination result. If the determination result indicates that correction is impossible, the process proceeds to a retry operation.

In the retry operation, the pickup is moved to the track on which the desired data is recorded once more and the reading operation is performed again. In this case, the error occurrence state is not constant, and the reading operation is performed again. This is because the data may be read when it is read. If the data cannot be read, it is common to repeat several times until the desired data can be read. If reading is not possible even with this operation, a low-speed reading mode is set, the rotation speed of the disk motor is lowered, the corresponding servo band is lowered, and the desired data is read again.

When the desired data is read, the next data is read. There are two methods for reading this data. In other words, there is a method of switching to the original high-speed reading mode and reading, or a method of reading while keeping the low-speed mode.

[0017]

However, in the method described above, in the case of a poor quality disk, the disk motor frequently repeats high speed and low speed, so that power consumption increases due to acceleration and deceleration of the disk motor, and heat is generated. Becomes larger. Also, since the acceleration / deceleration time of the disk motor is long,
Extremely low continuous data reading speed. Particularly, in a moving image reproduction, a required continuous data rate cannot be obtained, and a disadvantage that the moving image is stopped occurs.

On the other hand, in the method (1), when data that cannot be read in the high-speed mode happens to occur on a high-quality disk, the rotation speed is kept low, so that the utilization deteriorates, High-speed reading ability cannot be used. In particular, it is not suitable for reading and reproducing still image data that does not require continuity such as text data.

The present invention has been made in view of the above circumstances. Even if an error that data cannot be read due to a defect of a disk occurs, the disk motor frequently repeats high speed and low speed to reproduce moving pictures and audio. For playback of still images that do not require continuity such as text data, it is possible to play the disk without impairing the utilization of the high-speed playback function as much as possible without impairing the continuous data reading speed required for playback. It is an object of the present invention to provide a disk reproducing method and a disk reproducing apparatus that can perform the method.

[0020]

According to a first aspect of the present invention, in a disk reproducing method for reading digital information recorded on a disk, a defect on the disk is detected, and the defect is detected in a radial direction of the disk. Determining the range, changing the read mode of the disk due to the inability to read data from the disk due to the defect, and setting the read position on the disk beyond the radial direction range of the defect; In which the readout mode is restored.

According to a second aspect of the present invention, in a disk reproducing method for reading digital information recorded on a disk, a defect on the disk is detected, a range of the defect in a disk radial direction is determined, and the defect is detected. When the data cannot be read from the disk due to this, it is determined whether or not the data is moving image data and / or audio data in which an image moves continuously. If the data is moving image data or audio data, reading of the disk is performed. The mode is changed and the unreadable data is read again. If the data is read, the read mode is maintained until the end of the reproduction of the data. As a result of the determination, the data cannot be any of the moving image data and the audio data. For example, the read mode of the disk is changed to read the unreadable data again. When read in the keeping the read mode within a disk radial direction of the defect, characterized in that subsequently returning the read mode of the disk to the original.

According to a third aspect of the present invention, in the disk reproducing method of the first or second aspect, the defect is detected based on a signal read from the disk, and the disk diameter of the defect is determined based on the defect detection signal. It is characterized in that the range of the direction is determined.

According to a fourth aspect of the present invention, in a disk reproducing method for reading digital information recorded on a disk, when data cannot be read from the disk,
It is determined whether the data is moving image data and / or audio data in which an image moves continuously. If the data is moving image data or audio data, the read mode of the disc is changed to read the unreadable data again. When the data is read, the read mode is maintained until the end of the reproduction of the data, and as a result of the determination, if neither the moving image data nor the audio data, the read mode of the disc is changed and the unreadable data is changed. Is read again, and when it is read, the read mode of the disc is returned to the original mode.

According to a fifth aspect of the present invention, in the disk reproducing method of any one of the first to fourth aspects, the change of the read mode of the disk changes the rotation of the disk from a high speed to a low speed. Features.

According to a sixth aspect of the present invention, in the disk reproducing method according to any one of the first to fourth aspects, the change of the read mode of the disk changes the reading of signals from the disk from a constant rotation speed (CAV). Linear velocity constant (CL
V).

According to a seventh aspect of the present invention, in a disk reproducing apparatus for reproducing a disk on which digital information is recorded, a signal reading means for reading a signal from the disk in a set read mode, and a signal reading means for reading the signal from the disk by the signal reading means. Defect detection means for detecting a defect based on a read signal; defect range determination means for determining a range of the defect in a disk radial direction based on a defect detection signal from the defect detection means; and the signal reading means. Data reading means for reading desired data based on a signal read from the disk and outputting a read enable / disable signal; and a read disable signal from the data read means for setting a read mode of the signal read means. Change the settings and read the signal First control means for instructing the read means to read a signal from a non-readable portion of the disk, a read mode setting change instruction by the first control means, and the defect disk determined by the defect range determination means. And a second control unit for restoring the setting of the read mode outside the range of the defect in the radial direction of the disc based on the radial range.

According to an eighth aspect of the present invention, in a disk reproducing apparatus for reproducing a disk on which digital information is recorded, a signal reading means for reading a signal from the disk in a set read mode, and a signal reading means for reading the signal from the disk by the signal reading means. Defect detecting means for detecting a defect based on the read signal; defect range determining means for determining a radial direction range of the defect based on a defect detection signal from the defect detecting means; and the signal reading means Data reading means for reading desired data based on a signal read from the disk, and outputting a read enable / disable signal for notifying the success or failure of the read; and reading the signal by a read disable signal from the data read means. Set the read mode of the And the first control means for instructing the signal reading means to read a signal from the unreadable portion of the disk, and the read-out signal from the data reading means makes the data to be read continuous. Data determination means for determining whether the data is moving image data and / or audio data, a read mode setting change command from the first control means, a determination result by the data determination means, and the defect range determination means. When the discrimination result is neither the moving image data nor the audio data based on the range of the defect in the radial direction of the disc, the read mode is restored outside the range of the defect in the radial direction of the disc. And control means.

According to a ninth aspect of the present invention, in the disk reproducing apparatus of the seventh or eighth aspect, the defect determining means detects rotation of the disk, a defect detection signal from the defect detecting means, The rotation detection signal from the rotation detection means is input, and the read position of the disk is determined by the presence or absence of the defect detection signal from the defect detection means after substantially one rotation of the disk from the input of the defect detection signal. And a range determining means for determining whether the position is within the range in the radial direction.

According to a tenth aspect of the present invention, in the disk reproducing apparatus of the ninth aspect, the range determining means inputs a defect detection signal from the defect detecting means and a rotation detection signal from the rotation detecting means, and By inputting the output from the delay means and the output from the defect detection means, the delay means for outputting the detection signal after holding the detection signal for substantially one rotation of the disk, and thereby the read position of the disk is set at the defect level. Means for judging whether or not the position is within the range in the disk radial direction.

An eleventh aspect of the present invention relates to a disk reproducing apparatus for reproducing a disk on which digital information is recorded,
A signal reading unit for reading a signal from the disk in the set read mode; and a read enable / disable signal for reading desired data based on the signal read from the disk by the signal reading unit and notifying whether or not the reading is successful. The setting of the read mode of the signal reading means is changed by the data reading means to be output and the read disable signal from the data reading means, and the signal reading means is instructed to read the signal from the unreadable portion of the disk. A first control unit, a data determination unit that determines whether or not the data to be read is moving image data and / or audio data in which an image moves continuously based on a read disable signal from the data reading unit; The read mode setting change command by the control means and the determination result by the data determination means. And when the determination result is neither the moving image data nor the audio data, a second control means for returning the setting of the read mode to the original by a read enable signal from the data reading means. Features.

The twelfth aspect of the present invention provides the seventh to eleventh aspects.
In the disk reproducing apparatus according to any one of the above,
Wherein the read mode setting change command by the control means changes the rotation of the disk from high speed to low speed.

The thirteenth aspect of the present invention relates to the seventh to eleventh aspects.
In the disk reproducing apparatus according to any one of the above,
The read mode setting change command by the control means changes the setting of the signal reading from the disk at a constant rotational speed (CLV) from a constant rotational speed (CAV). .

The invention of claim 14 is the invention of claim 8 or 11
The disc reproducing apparatus according to any one of the above, wherein the data discriminating means discriminates based on information from a host computer.

The invention of claim 15 is the invention of claims 7 to 14
Wherein the data reading means processes a signal read from the disk by the signal reading means and reads desired data; and A determination unit for determining whether desired data has been read or not based on the error information and / or the uncorrectable information and outputting a read enable / disable signal;

Claims 1, 3, 5, 6, 7, 9, 10, 1
In the inventions 2, 13, and 15, defects due to scratches and dirt on the disk often extend over several tracks. In such a case, in order to reduce the influence of the defect that appears each time the disk rotates once. In the meantime, the range of the defect in the radial direction of the disk is specified, and the read mode of the disk data is changed from the high speed mode to the low speed mode or from the CAV mode to the CLV mode while the reading position is within the radial direction range of the defect. At a track position outside the defferent range, the mode is returned to the high-speed mode or the CAV mode to read data. As a result, high-speed playback functions can be effectively used to achieve good disc playback regardless of whether the image is a moving image or a still image without excessively lowering the continuous data reading speed by repeatedly changing the mode unnecessarily. Can be.

Claims 2, 3, 5, 6, 8, 9, 10, 1
In the inventions of 2, 13, 14, and 15, after the retry operation due to the unreadable error, the data to be read is still image data such as moving image data or audio data requiring continuity or text data not requiring continuity. In the case of moving image data or audio data, disc data is read continuously while the mode is changed from the high-speed mode to the low-speed mode or from the CAV mode to the CLV mode. ,
Video playback or audio playback can be performed stably. For still image data, based on the defect range,
By switching from the low-speed mode to the high-speed mode or from the CLV mode to the CAV mode when the range of the defect is exceeded, the high-speed playback function can be effectively used without repeatedly switching the read mode and imposing a load on the disk motor. be able to.

Claims 4, 5, 6, 11, 12, 13, 1
In the inventions 4 and 15, after the retry operation due to the unreadable error, it is determined whether the data to be read is moving image data or audio data requiring continuity or still image data such as text data not requiring continuity. In the case of moving image data or audio data, by continuing to read the disk data while changing the mode from the high-speed mode to the low-speed mode or from the CAV mode to the CLV mode, the read mode is not repeatedly changed due to the inability to read, and the data is stabilized. To play video or audio. Also,
In the case of still image data, the low-speed mode or the CLV mode is set only during the retry operation due to the inability to read, so that the high-speed reproduction function can be effectively used.

[0038]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a disc reproducing apparatus according to the first embodiment of the present invention. In FIG. 1, a disk 1 such as a CD-ROM and a DVD is placed on a disk motor 3 and is rotated by the disk motor 3. The rotation of the disk motor 3 is detected by a rotation detector 5. The pickup 7 includes a laser light emitter, an objective lens, and a four-segment photodetector. The pickup 7 is moved in the radial direction of the disk by a feed motor 9, and reads signals from the disk 1 on which digital information is recorded at a constant storage density.

The RF amplifier circuit 11 receives the output of the pickup 7, adds the output signals of the 4-split photodetector, generates an RF signal obtained by extracting a digital signal recorded on the disk 1, and outputs the RF signal of the 4-split photodetector. To extract a focus error signal and a tracking error signal.

The defect judging circuit 13 receives the RF signal output from the RF amplifier circuit 11 and the rotation detection signal indicating the number of rotations of the disk 1 such as the FG pulse signal from the rotation detector 5, and receives the disk 1 based on the RF signal. Then, a defect such as a scratch or dirt is detected, and a defect range in the disk radial direction is determined as the disk 1 rotates.

The level slice / PLL circuit 15 has an RF
The RF signal from the amplifier circuit 11 is binarized to obtain an EMF signal.
A PLL clock synchronized with the F signal is generated.

The signal processing circuit 17 has a level slice P
A binarized EMF signal and a PLL clock are input from the LL circuit 15, a synchronization signal of the disk 1 is detected using the PLL clock, and data separation, EMF demodulation, and data correction processing are performed based on the synchronization signal. The output terminal of the signal processing circuit 17 is connected to the host computer 21 via the interface 19, and the data read by the signal processing circuit 17 is transferred to the host computer 21 which is an external device. In the case where the signal cannot be corrected by the signal processing circuit 17,
Judgment is made based on error information of the correction block or CRC (judgment based on cyclic code), and a judgment result (read enable / disable signal) as to whether or not the data has been correctly read is output.

The system controller 23 is connected to the host computer 21 via the interface 19,
An operation command is transmitted to and received from the host computer 21. Address information of the disk 1 and a read enable / disable signal are input from the signal processing circuit 17 and an output of the defect determination circuit 13 is input, and the entire disk 1 is input. A control signal for performing operation control is output.

The servo circuit 25 receives a control signal from the system controller 23 and a tracking error signal from the RF amplifier circuit 11, and controls the drive of the feed motor 9 and the disk motor 3 via the respective drivers 27 and 29. .

Focus / tracking servo circuit 31
Is a control signal from the system controller 23 and R
The tracking error signal and the focus error signal from the F amplifier circuit 11 are input, and a lens control signal for adjusting the position of the objective lens of the pickup 7 is output.

FIG. 2 shows an example of the configuration of the defect determination circuit 13 shown in FIG.
The defect detection unit 41 detects a defect based on the RF signal from the RF amplifier circuit 11, and the disc 1 outputs the defect detection signal output from the defect detection unit 41 based on the rotation detection signal from the rotation detector 5. It comprises a delay circuit 43 that delays for one rotation, and a defect range determination unit 45 that determines a defect range in the disk radial direction based on the output from the defect detection unit 41 and the delay circuit 43.

The defect detecting section 41 comprises a low-pass filter (LPF) 51 and a comparator 53, for example, as shown in FIG.

If the disk 1 has scratches or dirt, the RF signal a drops below the normal level as shown in FIG. After the RF signal a has passed through the LPF 51, the signal b having passed through the LPF is compared with a predetermined reference signal c by the comparator 53, so that an output signal d as shown in FIG. Note that the reference signal c may be a fixed voltage or a signal based on the RF signal after passing through the LPF.

As described above, defects such as scratches and dirt on the disk can be detected with desired detection sensitivity by applying a frequency band filter such as LPF to the RF signal or adjusting the reference signal.

In FIG. 2, the output from the defect detector 41 is input to the delay circuit 43 and the defect range determiner 45. The delay circuit 43 has a delay element such as a shift register, for example, and delays and outputs the output signal of the defect detection unit 41 by the rotation detection signal from the rotation detector 5 while the disk 1 makes substantially one rotation.

The defect range determination section 45 receives the output signal of the defect detection section 41, sets a defect detection flag in accordance with the defect detection signal, compares the output of the delay circuit 43 with the output of the defect detection section 41, and When the defect detection signal is not output from the defect detection unit 41 at the output timing of the defect detection signal from the circuit 43, the defect detection flag is reset. If output, the defect detection flag is set as it is.
This operation is to check whether a defect appears at substantially the same position on the disk after one rotation when a defect is detected. If it appears, it can be determined that it is within the range of the defect in the radial direction of the disk, and if not, it can be determined that it is outside the range of the radial direction of the defect.

The rotation detector 5 can be constructed by attaching, for example, an FG pulse generator to the disk motor 3, but may be any as long as it can output information of at least one rotation of the disk 1. Alternatively, a rotation detection signal may be obtained by a method such as using an output of a Hall element of a brushless motor, using an induced voltage of a drive coil of a disk motor 3, or using address information or a synchronization signal of a disk. it can. Some of these operations are disclosed in Japanese Patent No. 1448247.

Next, the operation of the present embodiment will be described with reference to FIG. FIG. 5 shows a reading operation flow of the present embodiment.

The system controller 23 first sets a high-speed read mode in which the disk motor 3 rotates at a high speed (step 100), and outputs control signals to the servo circuit 25 and the focus / tracking servo circuit 31.
The desired data on the disk 1 is read by the pickup 7 (step 101).

If an uncorrectable error has occurred (step 102), a signal indicating that reading is impossible is output from the signal processing circuit 17 to the system controller 23, and the system controller 23 changes to a low-speed reading mode in which the disk motor 3 rotates at low speed. Then, a control signal is output to the servo circuit 25 and the focus / tracking servo circuit 31 so as to perform the retry operation, and the desired data is read again (step 104).

When desired data is read by this retry operation (step 102), the system controller 23 determines whether or not to return to the high-speed read mode based on the defect detection flag of the defect determination circuit 13 (step 105). That is, if the defect detection flag is set, it is determined that the defect is within the radial direction of the disk, and control is performed so that the next data is read in the low-speed read mode. If the defect detection flag has been reset, it is determined that the defect is out of the radial direction of the disc, and the mode is switched to the high-speed reading mode so that the next data is read.

Normally, defects such as scratches and dirt on a disc do not end with only one track. In the present embodiment, the defect detection flag is set while the pickup 7 is located on the track straddling the defect, and the high-speed / low-speed reading mode is set by the defect detection flag. Is switched, it is possible to prevent the continuous data reading speed from extremely lowering by repeating high and low speeds in a track within the defect range as in the related art, and stable reproduction can be performed. In addition, a track outside the defect range can be immediately returned to the high-speed reading mode, so that the high-speed reproducing function can be effectively used without waste.

The system for switching the rotation of the disk between high speed and low speed based on the range of the defect in the radial direction of the disk can be used in the CLV mode in which the rotational speed of the disk is changed in the radial direction to read data at a constant linear speed. The present invention can also be applied to a CAV mode for reading data at a constant rotation speed. In the CAV mode, the servo circuit 5 in FIG. 1 receives a rotation detection signal from the rotation detector 5 and drives and controls the rotation of the disk motor 3.
Although not shown, the speed control of the disk motor 3 in the CLV mode is controlled based on a synchronization signal recorded on the disk 1.

Instead of simply switching the rotation of the disk between high speed and low speed based on the range of the defect in the radial direction of the disk, the read operation is normally performed in the CAV mode, and the read operation is performed in the CLV mode in the defect range. You can also

FIG. 6 shows a disk reproducing apparatus according to a second embodiment of the present invention, in which a defect judging circuit 13 is omitted from FIG. 1 showing the first embodiment. In the present embodiment, as shown in FIG. 7, a read operation flow chart shows whether a read mode switched from high speed to low speed due to an unreadable error is returned to the original state when the next read operation is performed, or whether the low speed mode is maintained. The determination is made based on whether the data is moving image data (including audio data) or still image data.

That is, in this embodiment, the system controller 23 first sets the high speed mode in which the disk motor 3 rotates at a high speed (step 200), and the servo circuit 25 and the focus / tracking servo circuit 31
To read desired data in the high-speed read mode (step 201).

When an unreadable error occurs in the signal processing circuit 17 (step 202), the system controller 23 changes to a low-speed reading mode in which the disk motor 3 rotates at a low speed (step 203), and performs a retry operation. A control signal is output to the servo circuit 25 and the focus / tracking servo circuit 31 to read desired data again (step 204).

When the desired data is read by this retry operation (step 202), the system controller 23 determines whether the command from the host computer 21 is based on the moving image data or determines whether the command is a static data such as text data other than the moving image data. It is determined whether the data is based on the image data (step 205). If it is moving image data, the next data is read in the low-speed read mode (step 2).
01). If the data is still image data, the mode is returned to the high-speed reading mode and the next data is read (step 20).
0).

In this embodiment, the high-speed mode can be replaced with the CAV mode, and the low-speed mode can be replaced with the CLV mode.

In the case of a device such as a movie player which can determine the file type of recorded data, it is determined whether or not the data to be read is moving image data without depending on information from the host computer. be able to.

As is clear from the above description, according to the present embodiment, in the case of moving image data or audio data for which a certain continuous data rate needs to be secured, the low-speed mode is maintained after the retry operation. This makes it possible to stably reproduce a moving image (or a sound) without repeating high and low speeds due to inability to read. In the case of still image data that does not require continuity, such as text data, the high-speed reproduction function can be effectively used by setting the low-speed mode only during the retry operation due to the inability to read.

FIG. 8 shows a reading operation of the disk reproducing apparatus according to the third embodiment of the present invention. This embodiment combines the first embodiment and the second embodiment. Things. The disc reproducing apparatus according to the present embodiment has the same configuration as that shown in FIG.

In this embodiment, as shown in FIG. 8, first, the system controller 23 sets the read mode to the high-speed mode (step 300), and starts reading desired data (step 301).

When an unreadable error occurs in the signal processing circuit 17 (step 302), the system controller 23 changes the setting of the high-speed mode to the low-speed mode (step 303), performs a retry operation, and again outputs desired data. Go to read (step 304).

When the desired data is read by the retry operation (step 302), the system controller 23 determines whether the command from the host computer 21 is based on the moving image data (or audio data) or whether the command is a text other than the moving image data. It is determined whether the data is based on still image data such as data (step 305). If it is moving image data (or audio data), the next data is read in the low-speed read mode (step 30).
1).

On the other hand, if the data is still image data, it is next determined whether or not the defect detection flag of the defect determination circuit 13 is set, that is, whether or not the defect is within the defect range in the disk radial direction (step 306). If the flag is set (within the defect range), the next data is read in the low-speed read mode (step 3).
01). If the flag is reset (out of the defect range), the mode is returned to the high-speed reading mode and the next data is read (step 300).

In this embodiment, the high-speed mode can be replaced with the CAV mode, and the low-speed mode can be replaced with the CLV mode.

As is clear from the above description, according to the present embodiment, in the case of moving image data or audio data requiring a certain continuous data rate, the low-speed mode is maintained after the retry operation. This makes it possible to stably reproduce moving images and audio without repeating high and low speeds due to inability to read. For still image data that does not require continuity, such as text data,
By setting the low-speed mode only during the track range where the defect straddles after the retry operation due to the inability to read, the high-speed reproduction function can be effectively used without unnecessary and repetitive high-speed and low-speed loads on the disk motor.

[0074]

As described above, according to the present invention, after switching to the low-speed mode due to the inability to read data, the timing for returning the low-speed mode to the high-speed mode is determined based on the defect range in the disk radial direction. In addition, it is possible to minimize the influence of defects in moving image reproduction without excessively reducing the continuous data reading speed by repeating the high speed mode and the low speed mode unnecessarily. Furthermore, there are effects that an increase in power consumption and heat generation due to acceleration and deceleration of the disk motor can be suppressed, and a high-speed reproduction function can be effectively used without waste.

Further, according to the present invention, after switching to the low-speed mode due to the inability to read data, the low-speed mode is switched to moving image data requiring a certain continuous data reading speed or still image data requiring a low continuous data reading speed. By changing the timing of returning to the high-speed mode, the disc can be reproduced without hindering the reproduction of the moving image and while making the most effective use of the high-speed reproduction function.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a disk reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration example of a defect determination circuit illustrated in FIG. 1;

FIG. 3 is a circuit diagram illustrating a configuration example of a defect detection unit illustrated in FIG. 2;

FIG. 4 is a diagram illustrating waveforms of respective signals of a defect detection unit illustrated in FIG. 3;

FIG. 5 is a flowchart showing a read operation flow according to the first embodiment;

FIG. 6 is a block diagram showing a disc reproducing apparatus according to a second embodiment of the present invention.

FIG. 7 is a flowchart showing a reading operation flow according to the second embodiment;

FIG. 8 is a flowchart showing a reading operation flow according to the third embodiment;

[Explanation of symbols]

 1 disk 3 disk motor 5 rotation detector 7 pickup 9 feed motor 11 RF amplifier circuit 13 defect determination circuit 15 level slicer PLL circuit 17 ... Signal processing circuit 19 ... Interface 21 ... Host computer 23 ... System controller 25 ... Servo circuit 27, 29 ... Driver 31 ... Focus / tracking servo circuit 41 ... ... Defect detection unit 43... Delay circuit 45... Defect range determination unit 51... Low-pass filter 53... Comparator

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G11B 20/18 552 G11B 20/18 552F 572 572C 572F

Claims (15)

[Claims] 1. A disc reproducing method for reading digital information recorded on a disc, wherein a defect on the disc is detected, a range of the defect in a disc radial direction is determined, and a defect caused by the defect is determined. The read mode of the disk is changed when the data cannot be read, and when the read position on the disk exceeds the range of the defect in the disk radial direction, the read mode of the disk is restored. Playback method. 2. A disc reproducing method for reading digital information recorded on a disc, wherein a defect on the disc is detected, a range of the defect in a disc radial direction is determined, and the disc is caused due to the defect. When it is impossible to read data from the disk, it is determined whether or not the data is moving image data and / or audio data in which an image moves continuously. If the data is moving image data or audio data, the read mode of the disc is changed. The unreadable data is read again, and if it is read, the read mode is maintained until the end of the reproduction of the data. If the result of the determination is neither video data nor audio data, the disk is read. The mode is changed and the unreadable data is read again. Disk playback method characterized by maintaining the read mode within a disk radial direction of the defect, then returned to the original reading mode of the disk in. 3. The disk device according to claim 1, wherein the defect is detected based on a signal read from the disk, and a range of the defect in a radial direction of the disk is determined based on the defect detection signal. Disc playback method as described. 4. A disk reproducing method for reading digital information recorded on a disk, wherein when data cannot be read from the disk, whether the data is moving image data and / or audio data in which an image moves continuously. If the data is video data or audio data, the read mode of the disc is changed and the unreadable data is read again. If the data is read, the read mode is kept until the end of the reproduction of the data. If the result of the determination is that neither the moving image data nor the audio data, the read mode of the disc is changed and the unreadable data is read again, and if read, the read mode of the disc is changed. A disc reproducing method characterized by returning to the original state. 5. The method of claim 1, wherein the change of the read mode of the disk is
5. The disk reproducing method according to claim 1, wherein the rotation of the disk is changed from a high speed to a low speed. 6. The change of the read mode of the disk,
Reading of signals from the disk is performed at a constant rotational speed (CA).
5. The disk reproducing method according to claim 1, wherein the method is performed by changing the linear velocity (CLV) from V). 7. A disc reproducing apparatus for reproducing a disc on which digital information is recorded, a signal reading means for reading a signal from the disc in a set read mode, and a signal read from the disc by the signal reading means. Defect detection means for detecting a defect on the basis of a defect detection signal from the defect detection means; a defect range determination means for determining a range of the defect in the disk radial direction based on a defect detection signal from the defect detection means; Data reading means for reading desired data based on the output signal and outputting a read enable / disable signal; and changing a read mode setting of the signal read means by a read disable signal from the data read means. The signal reading means First control means for instructing a signal to be read from an unreadable portion of the disk; a read mode setting change instruction by the first control means; and a range of the defect in the disk radial direction determined by the defect range determination means. On the basis of,
A second control unit for restoring the setting of the read mode outside the range of the defect in the radial direction of the disk. 8. A disc reproducing apparatus for reproducing a disc on which digital information is recorded, a signal reading means for reading a signal from the disc in a set read mode, and a signal read from the disc by the signal reading means. Defect detection means for detecting a defect on the basis of a defect detection signal from the defect detection means; a defect range determination means for determining a range of the defect in the disk radial direction based on a defect detection signal from the defect detection means; Data reading means for reading desired data based on the output signal and outputting a read enable / disable signal for notifying the success or failure of reading; and a read disable signal from the data read means for setting a read mode of the signal read means. Change settings and previous First control means for instructing a signal reading means to read a signal from a non-readable portion of the disk; and moving image data in which an image to be read continuously moves by an unreadable signal from the data reading means; And / or data determination means for determining whether or not the data is audio data; a read mode setting change command issued by the first control means;
When the discrimination result is neither the moving image data nor the audio data based on the discrimination result by the data discriminating means and the disc radial range determined by the defect range discriminating means, the disc in the defect range is determined. A second control unit for restoring the setting of the read mode outside the radial direction. 9. The defect determining means receives a rotation detection means for detecting rotation of the disk, a defect detection signal from the defect detection means and a rotation detection signal from the rotation detection means,
A range for judging whether or not the read position of the disk is within the range of the defect in the radial direction of the disk based on the presence or absence of the defect detection signal from the defect detection unit after the rotation of the disk approximately one rotation from the input of the defect detection signal 9. The disk reproducing apparatus according to claim 7, further comprising a determination unit. 10. The range determination means receives a defect detection signal from the defect detection means and a rotation detection signal from the rotation detection means,
Delay means for outputting the defect detection signal after holding it for substantially one rotation of the disk; and outputting the output from the delay means and the output from the defect detection means, thereby setting the read position of the disk to 10. The disc reproducing apparatus according to claim 9, further comprising means for judging whether or not the defect is within a range in a disc radial direction. 11. A disc reproducing apparatus for reproducing a disc on which digital information is recorded, a signal reading means for reading a signal from the disc in a set read mode, and a signal read from the disc by the signal reading means. Data reading means for reading desired data based on the data, and outputting a read enable / disable signal for informing the success or failure of the read; and changing a read mode setting of the signal read means by a read disable signal from the data read means. A first control unit for instructing the signal reading unit to read a signal from a non-readable portion of the disk; and a moving image in which the data to be read continuously moves according to the non-readable signal from the data reading unit. Data determining means for determining whether the data is data and / or audio data Based on a read mode setting change command by the first control means and a determination result by the data determination means, when the determination result is neither the moving image data nor the audio data, by a read enable signal from the data reading means, A second control unit for returning the setting of the read mode to the original state. 12. The apparatus according to claim 7, wherein the read mode setting change command from the first control means changes the rotation of the disk from a high speed to a low speed. The disc reproducing device according to the above. 13. A read mode setting change command from said first control means changes a signal read from said disk at a constant rotational speed (CAV) to a constant linear speed (CV).
12. The disc reproducing apparatus according to any one of claims 7 to 11, wherein the setting is changed to a setting performed in (LV). 14. The disc reproducing apparatus according to claim 8, wherein said data discriminating means discriminates based on information from a host computer. 15. A signal processing means for processing a signal read from the disk by the signal reading means and reading desired data; and error information and / or correction from the signal processing means. Whether the desired data could be read based on the inability information,
15. The disk reproducing apparatus according to claim 7, further comprising: a determination unit configured to determine whether the read operation is impossible and output a read enable / disable signal.