KR100236015B1 - Erasable optical disc and wobble signal recording/reproducing device - Google Patents

Abstract

The present invention relates to a rewritable optical disc and a wobble signal recording / reproducing apparatus. In particular, the absolute position information of a sector is wobbled and recorded on one or both boundaries of a hill and a valley, and the PLL clock is allocated to some sections of the wobble signal instead of VFO information. By recording together with the absolute position information of the sectors, the hard-formatted physical header area is not needed, which increases the recording density of the disk and also detects the PLL clock directly from the wobble signal without adding additional VFO information, thereby facilitating PLL. In addition to being compatible with the reproduction-only optical disc, it is possible to control the same synchronization format as that of the reproduction-only optical disc.

Description

Rewritable Optical Disc and Wobble Signal Recording / Playback Device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rewritable optical disc. In particular, a rewritable optical disc and wobble signal for recording the absolute position information of a sector and information capable of applying a phase locked loop (PLL) in a wobble shape at the interface between a hill and a valley. A recording / playback apparatus.

In a conventional reproducing optical disc, information is recorded along a track of an information recording medium surface, and the recorded information is reproduced by constant rotation of the disc and tracking of the light beam.

On the other hand, in the case of a rewritable optical disc, since the first disc has no information, disc control and recording are impossible.

However, in the case of a recordable optical disc, for example, a CR-R or a CD-Rewritable disc, the first disc does not have information recorded and includes ATIP (Absolute Time In Pregroove) information by wobble or the like, so that rotation control is possible. In addition, by making the disc track by mountains and valleys and recording the information along the track, by recording the control information for random access and rotation control separately on the disc, tracking control is possible even on a blank disc in which no information signal is recorded. To do this.

In another type of recordable disc, there is a method in which information indicating the physical position of the disc is recorded in advance in the corresponding position, for example, the sector start position, on the disc as shown in FIG.

That is, the header area shown in FIG. 1 is hard-formatted, and is preformatted at the sector start position for each sector.

Thus, as shown in FIG. 2, the sector start position of the disc has an embossed area preformatted as pit information.

In this case, the header information includes the physical address and variable frequency oscillation (VFO) information of the sector and additional signals for protecting the information.

That is, the sync pattern contains the VFO information to indicate the rotational speed of the optical disk, the address mark to indicate the physical position of the sector, and the track number and sector number are used as the identification code of the sector.

In order to record data in a specific position of the disk, the VFO information for applying the PLL with the address of the corresponding position and the frequency corresponding to the position is required, and thus the information is detected in the header area.

Therefore, an embossed header area is required to identify the corresponding position. In this case, since the actual data cannot be recorded in the header area, the recording area for recording data is reduced.

In addition, the VFO information also enters the main data area. In the case of a compact disc (CD) or a digital versatile disc (DVD), one sector including a header has 26 synchronization (as shown in FIG. 3). Sync).

At this time, about three additional synchronizations are required for additional information including the physical address of the sector or the VFO information, and one sector consists of a total of 29 synchronizations.

This requires a process of forcibly adding or inserting an additional three syncs when recording or reproducing data on the disk, which not only increases the burden on software and hardware, but also differs from the format of a CD or DVD-ROM, which is a playback-only disk. There is a problem that is not compatible with.

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 the absolute position information of a sector in a wobbling shape at one or both boundary surfaces of a hill and a valley, and at the same time, the PLL clock instead of the VFO information is a part of the wobble signal. The present invention provides a rewritable optical disc and wobble signal recording / reproducing apparatus that not only increase the recording density of the disc, make it easy to hang the PLL, but also make it compatible with the optical disc for reproduction.

A feature of the rewritable optical disc according to the present invention for achieving the above object is that the absolute position information and the PLL clock corresponding to a specific section on the interface of the peak and valley tracks of the rewritable optical disc having signal tracks composed of hills and valleys. Is recorded in the wobbling shape.

A wobble signal recording apparatus of a rewritable optical disc according to the present invention includes a source clock generator, a PLL clock generator that divides the source clock to generate a PLL clock, and divides the PLL clock to generate a carrier frequency. A carrier frequency generator, a bit data clock generator for dividing the carrier frequency to generate a bit data clock, a biphase modulator for biphasically modulating absolute position information of the disc with the bit data clock, and switching And a recording unit for frequency-modulating the output of the bi-phase modulation unit in a wobble shape by frequency-modulating the carrier frequency, or recording the PLL clock in a wobble shape to the disc.

Another feature of a wobble signal recording apparatus of a rewritable optical disc according to the present invention includes a source clock generator, a PLL clock generator for dividing the source clock to generate a PLL clock, and dividing the source clock to generate a carrier frequency. A carrier frequency generator for generating a bit data, a bit data clock generator for dividing the source clock to generate a bit data clock, a biphase modulator for biphasically modulating absolute position information of a disk with the bit data clock, And a recording unit for frequency-modulating the output of the biphasic modulation unit at a carrier frequency to record in a wobble form on a disc or to record a PLL clock in a wobble form on a disc.

The wobble signal reproducing apparatus of the rewritable optical disc according to the present invention includes a wobble signal reproducing unit for reproducing a wobble signal from a difference between two signals, which are recorded in a wobbling shape on one interface of a track of a hill and a valley; A band pass filter for separating a PLL clock from the wobble signal reproduced by the wobble signal reproducing unit, a band pass filter for separating a clock of absolute position information from the wobble signal reproduced in the wobble signal reproducing unit, and the separated absolute position And a decoder that detects absolute position information by decoding a clock of information.

Another feature of the wobble signal reproducing apparatus of a rewritable optical disc according to the present invention is a wobble signal for reproducing a wobble signal from a difference between two signals, which are in-phased and recorded in a wobbling shape on both sides of a track of a hill and a valley. A band pass filter for separating the PLL clock from the wobble signal reproduced by the wobble signal reproducing unit, a band pass filter for separating the clock of absolute position information from the wobble signal reproduced in the wobble signal reproducing unit, and It is configured to include a decoder for detecting the absolute position information by decoding the clock of the separated absolute position information.

1 is a diagram showing the structure of a conventional rewritable optical disc.

FIG. 2 shows that the header area of FIG. 1 is an embossed area formed of pits.

FIG. 3 is a diagram illustrating a synchronization structure allocated to one sector in FIG.

4 is a block diagram of an apparatus for recording control information in a wobble form on a rewritable optical disc according to the present invention.

FIG. 5 is a diagram showing a structure in which ATIP wobble data and a PLL clock recorded in a wobble shape are allocated to one sector in FIG.

6 is a diagram illustrating an example in which the ATIP wobble data and the PLL clock according to the present invention are recorded in a wobble shape on both sides of a mountain and valley track.

7 is a diagram showing an example in which the ATIP wobble data and the PLL clock according to the present invention are recorded in a wobble shape on one interface of a track of a hill and a valley.

FIG. 8 is a block diagram of an apparatus for reproducing a recorded wobble signal as shown in FIG. 6 or FIG.

* Explanation of symbols for main parts of the drawings

41: source clock generator 42: PLL clock generator

43: carrier frequency generator 44: bit data clock generator

45: bi-phase modulation unit 46, 48: switching unit

47: frequency modulator 49: switching controller

71: wobble signal regeneration unit 72, 73: band pass filter

74: ATIP Decoder

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

4 is a block diagram showing an apparatus for recording an absolute position of a sector and PLL information in a wobbling shape on a rewritable optical disc according to the present invention.

4, the source clock generator 41 divides the source clock to generate a PLL clock, and divides the PLL clock of the PLL clock generator 42 to generate a carrier frequency. A generated carrier frequency generator 43, a bit clock generator 44 for dividing the carrier frequency to generate a bit data clock, and a biphase for biphase modulating absolute position information of the disc with the bit data clock. And a frequency modulator 47 for FM-modulating the output of the bi-phase modulator 45 to a carrier frequency and recording the data on a disk or recording a PLL clock on the disk.

At this time, the non-mentioned switching unit 46 switches the output of the PLL clock generator 42 and the output of the carrier frequency generator 43 to the frequency modulator 47 under the control of the switching controller 49, The switching unit 48 switches the Absolute Time In Pregroove (ATIP) data having absolute position information to the biphasic modulation unit 45 under the control of the switching controller 49.

In addition, the source clock is 26.16 Mbps, and the source clock is divided into 64 to generate a 408 kHz PLL clock, the PLL clock is divided into 4 to generate a carrier frequency of 102 kHz, and the carrier frequency is divided into 3 to divide the 34 kHz bit data clock. Generate.

In this case, the carrier frequency and the bit data clock may be generated from the source clock by dividing the source clock at a predetermined division ratio, respectively.

According to the present invention configured as described above, the source clock generator 41 generates a source clock of 26.16 Mbps.

In this case, the PLL clock generator 42 divides the 26.16 Mbps source clock into 64 to generate a 408 kHz PLL clock, and the carrier frequency generator 43 divides the PLL clock into four to generate a 102 kHz carrier frequency. The bit clock generator 44 divides the carrier frequency into three to generate a 34 kHz bit data clock.

When the absolute position information of the sector is recorded in the wobbling shape, the switching unit 48 is turned on, and the carrier frequency generator 43 is connected to the frequency modulator 47 through the switching unit 46. do.

In addition, when recording the PLL clock in a wobbling shape, the switching section 48 should be turned off, and the PLL clock generator 42 should be connected to the frequency modulation section 47 via the switching section 46.

That is, if the switching unit 48 is turned on by the switching control unit 49, and the carrier frequency generation unit 43 is connected to the frequency modulation unit 47 through the switching unit 46, the bi-phase modulation unit ( 45 may bi-phase modulate ATIP data with a bit data clock output from the bit clock generator 44, and the frequency modulator may FM-modulate the bi-phase modulated data with a carrier frequency output from the carrier frequency generator 43. Record in a wobble shape on the disc.

Here, the bi-phase modulation is a modulation that prevents the same logic signal from being repeated several times. '0' is modulated by '10' and '1' is modulated by '01'.

This prevents the data signal from going to the low frequency band.

On the other hand, if the switching unit 48 is turned off by the switching control unit 49, and the PLL clock generator 42 is connected to the frequency modulation unit 47 through the switching unit 46, the PLL clock is frequency modulated. The section 47 is bypassed and recorded in a wobble shape on the disc.

That is, when a PLL clock is allocated to a portion of the wobble signal, data can be distinguished when data is recorded, and data can be recorded using this PLL as a reference clock even if there is no separate VFO information.

At this time, the PLL clock has a high frequency region of about 408Khz and ATIP data having absolute position information of the sector has a carrier frequency based on a low frequency of 102Khz and is recorded in a wobble shape. The absolute position information of the PLL clock and the sector can be sufficiently distinguished and detected.

Generally, the address information of the ATIP wobble is composed of 42 bits of data. Therefore, as shown in FIG. 5, when 21 synchronization is assigned to the ATIP data wobble region and the remaining five synchronization units are assigned to the wobble region of the PLL clock, the control is sufficiently controlled within 26 synchronization. It is possible.

At this time, if the 5 synchronous PLL clock region is allocated to the front and rear of the ATIP data wobble region, the connection between the sectors can be smoothly configured.

Therefore, compatibility with data recorded in the format of a reproduction-only disc such as a DVD-ROM is possible.

At this time, the method of recording the ATIP data and the PLL clock in the wobbling shape is recorded on both sides of the tracks of the hills and valleys as shown in FIG. 6 and on the one of the tracks of the hills and valleys as shown in FIG. There is a way.

In the method of recording the ATIP data and the PLL clock in the wobbling shape on both sides of the mountain and valley tracks as shown in FIG. 6, wobble signals having the same phase with respect to the mountain or the valley are recorded on both sides of the mountain and valley tracks.

For example, up and down wobble signals having a phase-matched track for a mountain track include information on a corresponding mountain, such as ATIP data and a PLL clock, respectively. The difference between the two signals read through the pickup (A1) ATIP data and PLL clock of the corresponding peak L1 are detected.

In the method of recording in a wobbling shape on one interface as shown in FIG. 7, the phases do not have to coincide because the wobble signal has the absolute position information of the peak and valley and the PLL clock together.

That is, the difference between the up and down signals read through the pickup, for example, the ATIP data of the mountain L1 and the PLL clock are detected from A2, and the control information for the valley G1 is detected from A3.

FIG. 8 is a block diagram illustrating a device for reproducing ATIP data and a PLL clock recorded in a wobble shape as shown in FIG. 4. When the wobble signal reproducing unit 81 receives a high frequency signal RF reflected from a disk, FIG. Play the wobble signal.

That is, as shown in FIG. 6, when the wobble signal having the same phase is recorded at both boundary surfaces of the mountain and valley tracks, the wobble signal of the corresponding mountain L1 is obtained from the difference A1 between the two signals read through the pickup. Play it.

At this time, since the wobble signal is recorded with the low-frequency ATIP data and the high-frequency PLL clock, the PLL clock is separated through a band pass filter (BPF) 72 that passes only the high-frequency PLL clock.

Then, the ATIP clock is separated through the BPF 73 which passes only a low frequency carrier frequency.

At this time, the separated PLL clock is used as it is, and the separated ATIP clock is decoded by the ATIP decoder 74 to detect corresponding position information (ie, address).

On the other hand, when a wobbled shape is recorded on one interface of the track of the mountain and the valley as shown in FIG. 7, the difference between the two signals read through the pickup by the wobble signal reproducing unit 71, for example, the corresponding mountain L1 from A2. The wobble signal of the target G1 is reproduced from A3.

At this time, since the reproduced wobble signal is recorded with the low frequency ATIP data and the high frequency PLL clock, the PLL clock is separated through the BPF 72 and the ATIP clock is separated through the BPF 73, and then the PLL is separated. The clock is used as it is and the ATIP clock is decoded by the ATIP decoder 74 to detect the corresponding position information (ie, address).

On the other hand, during data reproduction, data is reproduced based on the reproduction clock (i.e., synchronous clock) of the recorded data.

As described above, according to the rewritable optical disc and wobble signal recording / reproducing apparatus according to the present invention, the absolute position information of a sector is wobbled in one or both boundary surfaces of the hill and valley, and at the same time, the PLL clock is wobbed instead of the VFO information. By allocating to some sections of the signal and recording them together with the absolute position information of the sector, a hard-formatted physical header area is not required, thereby increasing the recording density of the disc.

In addition, since the PLL clock is detected directly from the wobble signal without additional VFO information, not only can the PLL be easily dialed but also the control can be controlled in the same synchronous format as that of the read only optical disc. Can maintain compatibility.

Claims (3)

A rewritable optical disc having a signal track composed of hills and valleys, comprising: a first wobble portion in which absolute position information is modulated by a first frequency as a carrier at regular interval units on both sides or one boundary side of a hill and valley track; A rewritable optical disc comprising a second wobble portion of a second frequency opposed to a synchronous loop (PLL) clock. The rewritable optical disc of claim 1, wherein the first frequency is lower than the second frequency. On each side or one boundary side of the peak and valley track, the absolute position information includes a first wobble portion modulated with a first frequency as a carrier and a second frequency corresponding to a phase locked loop (PLL) clock. A wobble signal reproducing section for detecting a wobble signal from a rewritable optical disc comprising a second wobble section; A first band pass filter separating the first wobble signal corresponding to the first wobble unit from the wobble signal reproducing unit; A second band pass filter that separates a second wobble signal corresponding to a second wobble unit from the wobble signal reproducing unit; And a decoder for decoding the first wobble signal to reproduce absolute position information.