KR100219276B1 - Apparatus and method of reproducing control of disk speed - Google Patents

Abstract

The present invention relates to a disc double speed playback control method and apparatus for detecting and tracking a focusing / focusing error level when a disc / tracking error occurs when the disc is reproduced (speeding) and performing a more accurate tracking / focusing by varying the disc drive speed. It is about.

To this end, the present invention comprises the steps of detecting the surface vibration / eccentricity of the disk by the signal detected from the rotating disk during double speed playback, determining the playback speed according to the detected surface vibration / eccentricity of the disk, The disk rotation speed is controlled to suit the determined playback speed.

Further, an apparatus for retrying data reproduction due to a data reproduction error, comprising: a direct current (DC) level detecting means for detecting a direct current (DC) level of a tracking / focusing error signal detected during disc reproduction; And control means for outputting a reproduction speed control signal, a reproduction speed determining means for determining a reproduction speed according to the output control signal, and a drive means for varying a disc drive speed according to the determined reproduction speed.

Description

Disc double speed playback control method and apparatus

The present invention relates to a disc double speed playback control method and control apparatus. In particular, when a disc is played back (double speed), a tracking / focusing error level is detected when a tracking / focusing error occurs and the disc drive speed is changed accordingly, thereby providing more accurate tracking / focusing. It was intended to be done.

The conventional disc reproducing apparatus includes an optical pickup (1) for reflecting light onto a disc (11) to read out a signal, an RF amplifier (2) for converting and amplifying a light reflected current signal into voltage, and the like. And a digital signal processor 20 for converting the signal read from the RF amplifier 2 into a digital signal, a microcomputer 5 for controlling the digital signal processor 20, and the digital signal processor 20. It consists of a motor drive circuit (9) for receiving the spindle motor drive signal to drive the spindle motor (10).

The digital signal processing unit 20 further includes a data reproducing unit 3 for demodulating a digital signal from the RF signal of the RF amplifier 2 and a synchronization signal carried in the data reproduced by the data reproducing unit 3. According to the output state of the synchronization signal detecting unit 4 to be extracted, the reproduction speed determining unit 6 for determining the reproduction speed by the command from the microcomputer 5, and the predetermined state according to the output state of the reproduction speed determining unit 6, Comparing the clock generation section 7 outputted to the phase comparison section 8 with the regeneration synchronous signal and the clock phase corresponding to the regeneration speed determined by the microcomputer 5 to generate the drive signal of the spindle motor 10. It is comprised by the phase comparison part 8. As shown in FIG.

Referring to Figure 2 attached to the operation of the prior art configured as described as follows.

As is well known, spindle motor control is to control the disk to be rotated at a target speed.

First, the optical pickup 1 reads data from the disk 11 and transfers the data to the RF amplifier 2. The RF amplifier 2 converts and amplifies the light reflected current signal into a voltage to convert the data in the digital signal processing unit 20. Output to the reproducing section (3).

Accordingly, the data reproducing section 3 demodulates the digital signal from the RF signal and applies it to the synchronizing signal detecting section 4, and the synchronizing signal detecting section 4 displays the synchronizing signal loaded on the data reproduced by the data reproducing section 3. Is extracted and added to the phase comparator 8.

The phase comparator 8 receives the output signals from the sync signal detector 4 and the clock generator 7, and the phase of the clock has a synchronization signal extracted from data read from the disk 11 and a target speed. Compare and transmit the corresponding error signal to the motor drive circuit (9) to control the speed of the spindle motor (10).

That is, the phase comparator 8 detects the current regeneration speed as a synchronous signal from the data and compares it with the target speed input from the microcomputer 5 to issue an error signal for controlling the spindle motor 10 to produce a spindle motor ( 10) to control.

FIG. 2 shows an operation flowchart of a conventional disk data read retry method. When the data cannot be read due to disc eccentricity, surface vibration, or other impact during data reading, the number of times set by the microcomputer 5 is repeated. This section describes the process of error handling when it fails to read after trying.

However, in this prior art, since most CD-ROM disks store data in a CLV (Constant Linear Velocity) method, reading data on the inner circumference of the disk is about 2.5 times faster than reading the data on the outer circumference. The spindle motor must be rotated. For example, at 8x speed, it should rotate at about 4,300rpm in the inner circumference, but only 1,800rpm for reading the outermost circumference. Therefore, when reading the data of the inner circle, there is a problem that the data cannot be read from the disc having eccentricity or surface vibration due to the mechanical vibration and the eccentricity and surface vibration component of the CD-ROM disk itself. There was this.

That is, reading data at the same speed irrespective of a disc having a large amount of eccentricity or surface vibration, or a disc not having a large amount of eccentric vibration, may cause a relatively poor playability or failure to read data on the eccentric or surface vibration disk.

In other words, if the data cannot be read, the number of retries specified by the microcomputer is retried, but the retry is performed at the current double speed. Therefore, error processing frequently occurs. This phenomenon is more likely to occur more seriously with a high speed CD-ROM drive. There was a problem.

Accordingly, the present invention provides a disc double speed playback control method and control apparatus for performing more accurate tracking / focusing by detecting a tracking / focusing error level when a disc / tracking error occurs and varying the disc drive speed according to the disc playback (double speed). To provide that purpose.

The technical method of the present invention for achieving the above object is to detect the surface vibration / eccentricity of the disk by the signal detected from the rotating disk during double speed playback, and the playback speed according to the detected surface vibration / eccentricity of the disk Determining the and rotating the disk to suit the determined playback speed.

In addition, the technical means of the present invention is an apparatus for retrying data reproduction due to a data reproduction error, the apparatus comprising: direct current (DC) level detection means for detecting a direct current (DC) level of a tracking / focusing error signal detected during disc reproduction; Control means for outputting a playback speed control signal in accordance with the detected DC level, playback speed determining means for determining a playback speed in accordance with the output control signal, and drive means for varying a disk drive speed in accordance with the determined playback speed It is configured to include.

1 is a block diagram of a conventional disc reproducing apparatus.

2 is an operation flowchart of a conventional disc data read retry method.

3 is a block diagram of a disc reproducing apparatus according to the present invention;

4 is an operation flowchart of a disc double speed reproduction control method according to the present invention;

5 is a waveform diagram of output comparison between a disk tracking error and focus error signal and a low pass filter;

Table 1 is a target double speed state chart according to the output of the low pass filter.

* Explanation of symbols for the main parts of the drawings

1: optical pickup 2: RF amplifier

3: data reproducing unit 4: synchronization signal detecting unit

6: Playback speed determining unit 7: Clock generator

8: phase comparison unit 9: motor drive circuit

10: spindle motor 11: disc

20: digital signal processor 30: microcomputer

31: first A / D converter 32: second A / D converter

33: first low pass filter 34: second low pass filter

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 shows a block diagram of a disc reproducing apparatus according to the present invention. As shown in FIG. 3, an optical pickup 1 for reading a signal by reflecting light onto the disc 11 and a voltage of a light reflected current signal are shown. The RF amplifier 2 for converting and amplifying the signal, the digital signal processor 20 for converting the signal read out from the RF amplifier 2 into a digital signal, and the tracking error signal and focus error output from the RF amplifier 2. The signal level of the first and second low pass filters 33 and 34 and the first and second low pass filters 33 and 34 to filter the signal and transmit the signal to the microcomputer 30 is first. And a microcomputer 5 for controlling the digital signal processor 20 by sensing the second A / D converters 31 and 32 and a spindle motor drive signal from the digital signal processor 20. The motor drive circuit 9 which drives the motor 10 is comprised.

The digital signal processing unit 20 further includes a data reproducing unit 3 for demodulating the digital signal from the RF signal of the RF amplifier 2 and a synchronization signal carried in the data reproduced by the data reproducing unit 3. A predetermined clock is set in accordance with the output of the synchronization signal detection section 4 to be extracted, the playback speed determination section 6 for determining the playback speed by a command from the microcomputer 30, and the playback speed determination section 6; Comparing the clock generation unit 7 outputted to the phase comparison unit 8 with the regeneration synchronization signal and the clock phase corresponding to the regeneration speed determined by the microcomputer 30 to generate a drive signal of the spindle motor 10. It is comprised by the phase comparison part 8. As shown in FIG.

When described with reference to the fourth, fifth and Table 1 attached to the operation and effect of the present invention made as described above are as follows.

TABLE 1

4 is a flowchart illustrating a method of controlling a disc double speed playback according to the present invention. As shown in FIG. 4, when data cannot be read during play, it is mostly caused by eccentricity, surface vibration, or damage to the disk. Many times.

In this case, conventionally, the data is read again with a few retries, or error processing is performed in case of failure. However, the present invention measures the amount of eccentricity or surface vibration from the focus error signal and the tracking error signal. Has adopted a method to retry.

In this case, the current reproduction speed is n times and the error signal components inputted through the first and second low pass filters 33 and 34 of FIG. 3 are converted into the first and second A / D converters 31 and ( 32) and convert the amount of eccentricity or surface vibration according to the error signal level.

This can be implemented by creating a separate table in a predetermined program of the microcomputer 30.

And set the speed to reduce the influence by the current surface vibration amount or eccentricity. In the worst case, even if the speed drops to 1x, it reads a certain length of unread data and then returns to the initial playback speed to reduce the case where data cannot be read from the disk with the surface vibration component or the eccentric disk. have.

A method for preventing data reproduction error due to the above tracking / focusing error will be described.

First, the DC level of the tracking / focusing error signal detected during disc playback is detected through the first and second low pass filters 33 and 34.

The detected DC level is applied to the reproduction speed determining unit 6 through the first and second A / D converters 31 and 32 to determine the reproduction speed.

The signal corresponding to the reproduction speed determined as described above is applied to the motor drive circuit 9 through the clock generator 7 and the phase comparator 8 to control the drive speed of the motor so that the drive speed of the disc can be varied. will be.

FIG. 5 is a waveform diagram showing the output of the disk tracking error and focus error signal and the low pass filter in the present invention. (A) shows the tracking error and focus error signal type of the disk without eccentricity or surface vibration. This is constant.

On the other hand, (b) is a type of focus error signal or eccentric tracking error signal of a disk with surface vibration, and the DC level is unstable. The degree of change in the DC level is more severe as the amount of eccentricity or surface vibration is increased.

(C) and (D) show the signal states after passing the error signals of (A) and (B) through the low pass filters 33 and 34, respectively. The amount of change in level indicated by Vp-p in (d) becomes larger in the inner circumference of the disk and the frequency is higher.

In the present invention, the target reproduction speed is controlled directly instead of the n-1 double speed control according to the data reproduction error level. The target double speed to the output Vp-p of the low pass filter is shown in Table 1.

As described above, according to the present invention, an eccentricity and surface of the disk may occur when some data cannot be read due to surface vibrations or scratches caused by discrepancy of the central hole, disk eccentricity or disk deflection generated when the disk is not an exact circular shape. By retrieving the data by retrieving the vibration amount and determining the double speed, the data can be read from the disk without being affected by eccentricity, surface vibration or scratches, thereby improving the reliability of products such as high speed CD-ROM drives. It works.

Claims (11)

Detecting the surface vibration or eccentricity of the disk by a signal detected from the rotating disk during double speed playback; Determining a playback speed according to the detected surface vibration or eccentricity of the disk; And controlling the disk rotation speed to suit the determined playback speed. The method of claim 1, The detecting surface vibration or eccentricity may include converting a tracking / focusing error signal detected during disc playback into a DC value, comparing the detected error value with a predetermined reference value, And detecting a surface vibration or an eccentric amount. The method of claim 1, And the reproducing speed determining step is performed at a low speed at which no surface vibration or eccentricity is generated by the detected surface vibration or eccentricity. The method of claim 1, And the regeneration speed determining step determines the spindle motor speed by 1 times lower than the current speed by the detected surface vibration or eccentricity. The method according to claim 1, 3 or 4, And reproducing an error if data reproduction fails even if the data speed drops to a constant speed (1x speed). An apparatus for retrying data reproduction due to a data reproduction error, DC level detection means for detecting the DC level of the tracking / focusing error signal detected at the time of disc reproduction, control means for outputting a reproduction speed control signal in accordance with the detected DC level; Playback speed determining means for determining a playback speed according to the output control signal; And a drive means for varying the disc drive speed in accordance with the determined playback speed. In an apparatus for retrying data reproduction due to a data reproduction error, DC level detecting means for detecting the DC level of the tracking / focusing error signal detected at the time of disc reproduction; Control means for outputting a reproduction speed control signal in accordance with the detected DC level; Reproduction speed determining means for determining a reproduction speed by varying a reference clock according to the output control signal; Phase comparison means for comparing the phase of the synchronization signal detected from the reference clock and the disc of the determined reproduction speed; And a drive means for controlling the disc drive speed in accordance with the comparison result of the phase comparison means. Detecting a DC level of the tracking / focusing error signal detected during disc playback; Determining a reproduction speed according to the detected DC level; And controlling the motor drive speed according to the determined reproduction speed. The method of claim 8, The regeneration speed determining step includes detecting a surface vibration or an eccentric amount of the disc according to the DC level of the tracking / focusing error signal detected during disc reproducing; And determining the playback speed at n-1 times the current n times speed when the detected surface vibration or eccentricity level of the disc is equal to or greater than a preset reference level. DC level detecting means for detecting the DC level of the tracking / focusing error signal detected at the time of disc reproduction; Control means for outputting a reproduction speed control signal in accordance with the detected DC level; Playback speed determining means for determining a playback speed according to the output control signal; And a drive means for varying the disc drive speed in accordance with the determined reproduction speed. DC level detecting means for detecting the DC level of the tracking / focusing error signal detected at the disc playback; Control means for outputting a reproduction speed control signal in accordance with the detected DC level; Reproducing speed determining means for determining a reproducing speed by varying a reference clock according to the output control signal; Phase comparison means for comparing the phase of the synchronization signal detected from the reference clock and the disk of the determined reproduction speed; And a drive means for controlling a disc drive speed in accordance with a comparison result of said phase comparison means.

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