KR100223883B1 - Rotation control device of recorder and reproducer for optic disc - Google Patents

Abstract

A rotation control apparatus for dually controlling a spindle motor at the time of recording and reproducing data on an optical disk, and more particularly, a first PLL for matching a phase of a first pattern information with a phase of a first reference frequency, and a second pattern information. A second PLL for matching the phase of the frequency and the first reference frequency, a third PLL for matching the phase of the synchronization signal and the second reference frequency, and a pseudo-synchronization inserting unit for inserting similar synchronization at a predetermined position of the third PLL And a control unit for controlling the rotation of the disc by combining the output of the first PLL and the output of the second PLL during recording, and controlling the rotation of the disc by combining the output of the first PLL and the output of the pseudo-synchronous inserting unit during playback. It is configured to include, the dual-control the spindle motor by using a plurality of pattern information at the time of recording data on the optical disk, and synchronization during reproduction of the data recorded on the optical disk By inserting pseudo synch into the area where there is no wave number, dual control of the spindle motor using pattern information and sync signal with synchronicity to record the data accurately, and compensate for the deterioration on the disk during repetitive recording. Can be played correctly.

Description

Rotation control device of optical disc recorder

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for recording and reproducing data on an optical disc, and in particular, by controlling the spindle motor at the time of recording and reproducing data on an optical disc, thereby reducing errors in data generated during recording and accurate data during reproduction An apparatus for controlling rotation of an optical disc recording / reproducing apparatus for reading a document.

Conventionally, when the recorded data is reproduced, the sync code portion of the recorded data is detected as shown in FIG. 1 (b) to control the rotation of the disk or to use information pre-formatted on the disk itself. To control the rotational speed of the disc.

As shown in Fig. 1A, the same length sector format is used throughout the disk.

Here, one sector is divided into a synchronization area of 32 channel bits and a data area of 1456 channel bits.

When the synchronization signal of the synchronization region is detected as shown in FIG. 1 (b), the spindle servo frequency becomes a low frequency of about 16 Khz.

At this time, when the disk rotates and falls within a certain range, the spindle servo is engaged, that is, the rotation control of the spindle motor is locked to read the recorded data.

The spindle motor is controlled by a phase locked loop (PLL) or digital PLL as shown in FIG.

Referring to FIG. 2, a phase detector 21 for comparing a phase of an input frequency Fin and a reference frequency Fref, and a low pass filter (LPF) for converting an output of the phase detector 21 into a direct current. (22) and a voltage controlled oscillator (hereinafter referred to as VCO) which feeds an oscillation frequency proportional to the direct current of the LPF 22 to the input frequency Fin stage of the phase detector 21. 23).

In FIG. 2 configured as described above, the reference frequency Fref is a reference clock in the case where the disc is assumed to be accurately controlled in speed, and the input frequency Fin is a synchronous clock generated when data is reproduced from the disc.

That is, the phase detector 21 compares the phase between the reference frequency Fref as shown in FIG. 3A and the frequency Fin of the reproduced clock to output the pulse having the pulse width according to the phase difference to the LPF 22.

The LPF 22 filters the high frequency that may flow from the phase detector 21 to convert the output of the phase detector 21 into a direct current.

The VCO 23 oscillates a frequency proportional to the direct current output from the LPF 22 and feeds it back to the phase detector 21.

At this time, if the spindle motor control clock input from the reproduction data, that is, the input frequency Fin fed back to the phase detector 21 is equal to FIG. 3B, the disk rotates faster because the input frequency Fin is faster than the reference frequency Fref. In this case, the spindle motor is controlled to lower the rotation of the disk.

In addition, when the input frequency Fin is equal to FIG. 3C, the input frequency Fin is slower than the reference frequency Fref, indicating that the disk is rotating slowly. In this case, the spindle motor is controlled to increase the rotation of the disk.

Then, when the reference frequency Fref and the input frequency Fin fed back to the phase detector 21 are locked as shown in FIG. 3D, data is read from the disc.

This conventional spindle motor rotation control is applicable only to the disc for regeneration. In other words, when the data is reproduced from the disc, the synchronization code is generated constantly (for example, at regular intervals), thereby making it easy to control the speed of the motor.

However, in the recordable disk, since there is no sync code in data recording and only pattern information, when controlling the motor speed based on one pattern, the servo control is difficult because the frequency is low as low as about 16 kHz as shown in FIG.

Therefore, there is a problem that it is difficult to record accurate data.

In addition, there is a problem that not only the synchronization signal is detected in the header area and the buffer area when data is reproduced, but also that the reproduction is not performed correctly when the synchronization signal is not constantly detected due to deformation of the pit generated during repeated recording.

In addition, if the spindle servo fundamental frequency is low, it affects the servo system at the time of reproduction, and an error occurs in the reproduction data or the servo becomes unstable at the time of reproduction.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to record data accurately by dually controlling the spindle motor by using a plurality of pattern information when recording data on the optical disk. It is to provide a rotation control device of.

Another object of the present invention is to compensate for the deterioration on the disc during repetitive recording by inserting a similar sync in the region where there is no sync frequency during reproduction of the data recorded on the optical disc and controlling the spindle motor with pattern information dually. An object of the present invention is to provide a rotation control apparatus of an optical disc recorder that reproduces accurate data.

A feature of the rotation control apparatus of the optical disk recorder according to the present invention for achieving the above object is a first PLL for matching the phase of the frequency of the first pattern information to the phase of the first reference frequency, and the second pattern. A second PLL for matching the phase of the frequency of the information to the phase of the first reference frequency, a third PLL for matching the phase of the synchronization signal to the phase of the second reference frequency, and a predetermined position of the frequency output from the third PLL A synchronizing inserting unit for inserting a synchronizing synchronism into the control unit, and synthesizing the output of the first PLL and the output of the second PLL during recording to control the rotation of the disc, and the output of the synchronizing inserting unit and the output of the synchronizing synchronizing unit during reproduction. It is configured to include a control unit for synthesizing the rotation of the disk.

1 is a waveform diagram showing a spindle servo fundamental frequency for controlling a spindle motor by detecting a synchronous portion in a sector structure and a sector structure of a general disk.

2 is a block diagram showing a general PLL

3A is a waveform diagram showing a reference frequency of FIG. 2.

3B-3D are waveform diagrams showing the input frequency when the disk is fast, slow or locked

4 is a waveform diagram showing a synchronization structure capable of controlling the sector structure of a rewritable disc and the number of rotations within a sector which may occur during recording / reproducing;

Fig. 5 is a block diagram showing the configuration of the rotation control apparatus of the optical disc recorder according to the present invention.

* Description of the symbols for the main parts of the drawings *

50: PLL Circuit 51: First PLL

52: 2nd PLL53: 3rd PLL

54: pseudo-synchronous insertion unit 55: multiplexer

56: adder

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

FIG. 4A shows a sector structure of a rewritable disc, which is divided into a preformatted header area containing pattern information, a sync area, and a data area.

At this time, the same pattern may come from the pattern 1-pattern 4 of the said header area | region, and a different pattern may come.

The ± K value of the buffer area is randomly assigned a length to compensate for deterioration that occurs during repeated recording.

4 (b) to (d) are synchronization signals capable of controlling the number of rotations within a sector that may occur during recording / reproducing, and FIG. 4 (b) periodically detects pattern 1, and FIG. (c) periodically detects the pattern 1 and the pattern 4, and FIG. 4 (d) detects the synchronization code.

In case (d) of FIG. 4, data is 91 bytes in total 2697 bytes, and synchronization is 2 bytes, that is, one period of synchronization becomes 93 bytes. From this, if there are periodic synchronizations within one sector, 29 synchronizations exist. do.

However, only 26 sync codes exist and 3 syncs do not exist.

The three synchronizations which do not exist correspond to a header area and a buffer area.

Therefore, at this time, assuming that there is synchronization at a predetermined interval, if similar synchronization is generated, 29 will be generated.

Fig. 5 is a block diagram showing the configuration of the rotation control apparatus of the optical disk recorder according to the present invention.

Referring to FIG. 5, the first PLL 51 for controlling the rotational speed of the spindle motor by comparing the phase of the frequency of the first fundamental frequency Fref1 and the pattern 1, and the frequency of the first fundamental frequency Fref1 and the pattern 4 To the second PLL 52 which controls the rotational speed of the spindle motor by comparing the phases of the two phases and the third PLL 53 which controls the rotational speed of the spindle motor by comparing the phase of the synchronization signal with the second fundamental frequency Fref2. The PLL circuit is constructed.

Then, the similar synchronization inserting unit 54 for inserting similar synchronization at a predetermined position of the frequency output from the third PLL 53 and the second PLL 52 or the third PLL 53 according to recording / reproducing. The multiplexer 55 selects and outputs an output, and an adder 56 for controlling the rotation of the motor by combining the output of the first PLL 51 and the output of the multiplexer 55.

In the present invention configured as described above, since there is no area corresponding to synchronization and data at the time of recording, the rotation of the spindle motor is controlled using the signals of patterns 1 and 4, and the reference frequency Fref1 is about 676 Hz.

Since the synchronization signal and the data are recorded during reproduction, the rotation of the spindle motor is controlled using the signal and the synchronization signal of the pattern 1, wherein the first reference frequency (Fref1) compared with the pattern 1 is about 676 Hz. The second reference frequency Fref2 compared with the signal is about 19.6 KHz.

That is, the first PLL 51 compares the phase of the first reference frequency Fref1 with the frequency of the pattern 1 and outputs an oscillation frequency proportional thereto, thereby locking the frequency of the pattern 1 to the first reference frequency, and the second PLL. Reference numeral 52 compares a phase of the frequency of the first reference frequency Fref1 and the pattern 4 and outputs an oscillation frequency proportional thereto, thereby locking the frequency of the pattern 4 to the first reference frequency, and the third PLL 53 is configured to generate the first reference frequency. The phase of the second reference frequency Fref2 and the synchronization signal are compared and an oscillation frequency proportional thereto is output to lock the synchronization signal to the second reference frequency.

At this time, the synchronizing synchronization inserting unit 54 counts the output of the third PLL 53 and determines that the synchronizing signal is missing, or inserts the synchronizing synchronizing at the position when the synchronizing signal is missing.

The multiplexer 55 selects the output of the second PLL 52 and outputs it to the adder 56 at the time of recording, and selects the output of the pseudo-synchronous inserter 55 and outputs to the adder 56 at the time of reproduction. .

Therefore, at the time of writing, the output of the first PLL 51 and the output of the second PLL 52 are combined in the adder 56 through the multiplexer 55 to control the rotation speed of the spindle motor dually.

At the time of regeneration, the output of the first PLL 51 and the output of the pseudo-synchronous inserting unit 54 are combined by the adder 56 through the multiplexer 55 to control the rotation speed of the spindle motor.

The reason for controlling the rotation of the spindle motor in this way is to increase the rotation servo frequency by performing the dual control using the pattern 1 and the pattern 4 since only the information corresponding to the patterns 1 to 4 is recorded at the time of recording. .

Therefore, since the rotation servo frequency is about two times higher, accurate data can be recorded.

Further, during reproduction, the frequency band can be increased by detecting the start position of the sector using pattern 1 to read data in accordance with the change in the shape of the pit generated during recording, and by performing rotation control by inserting synchronization and similar synchronization.

Therefore, it is possible to stably perform the rotation control and to reproduce the correct data.

As described above, according to the rotation control apparatus of the optical disk recorder according to the present invention, the data is accurately recorded by dually controlling the spindle motor by using a plurality of pattern information when recording the data on the optical disk, When the recorded data is reproduced, a similar sync is inserted in an area where there is no sync frequency, and then the spindle motor is dually controlled using a sync signal with pattern information and a similar sync to compensate for the deterioration on the disk during repeated recording. It has the effect of playing back correctly.

Claims (2)

A first phase locked loop for locking the frequency of the first pattern information to the first reference frequency; A second phase locked loop for locking the frequency of the second pattern information to the first reference frequency; A third phase locked loop for locking the sync signal to a second reference frequency; Pseudosynchronization inserting means for inserting pseudosynchronization into a predetermined position of a frequency output from the third phase synchronizing loop; The rotation of the disc is controlled by combining the output of the first phase lock loop and the output of the second phase lock loop during recording, and the output of the first phase lock loop and the output of the pseudo-synchronous inserting means are combined to reproduce the disc. And a control means for controlling the rotation. The method of claim 1 wherein the control means A rotation control apparatus for an optical disc recorder, characterized in that the start of a sector is detected at the time of reproduction by using the output of the first phase synchronization loop.

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