KR100601727B1 - Disk having pits to detect amount of servo error and detrack - Google Patents

Abstract

The present invention relates to a disc for recording and reproducing digital data, and more particularly to a disc having pits for detecting the servo error amount and the servo detrack amount.

The disc according to the present invention has a data area divided into sectors, each sector has a header indicating an address, and the header has a first header and a second header which are recorded staggered from side to side at the center point of the track. 2. A header having an address area in which an address of a sector is recorded and a sync signal area in which a sync signal for detecting a signal recorded in the address area is recorded, wherein the first size I1 and the first size correspond to the first header. And pits corresponding to the synchronization signals of the first and second heads so that the size ratio of the second size I2 corresponding to two headers corresponds to the amount of servo tilt error.

According to the disc according to the present invention, the recording and reproducing apparatus maintains stable servo control by detecting the servo error amount and the detrack amount by the pits recorded on the disc.

Description

Disk having pits to detect amount of servo error and detrack}

FIG. 1A shows the physical shape of the land track, and FIG. 1B shows the waveform of the push-pull signal in the land track.

2A shows the physical shape of the groove track, and FIG. 2B shows the waveform of the push-pull signal in the groove track.

3 is an enlarged view of the header area illustrated in FIGS. 1A to 2A.

4A and 4B show a push-pull signal and a sum signal obtained when the laser spot passes through the header section of the groove track, respectively, in FIG. 3.

FIG. 5 shows a configuration of an apparatus for obtaining a reproduction signal shown in FIG.

Figure 6 is a block diagram showing the configuration of one embodiment of a servo error detection apparatus suitable for a disc according to the present invention.

7 (a) to 7 (e) are waveform diagrams showing the operation of the apparatus shown in FIG.

8 is a block diagram showing the configuration of another embodiment of a servo error detection apparatus suitable for a disc according to the present invention.

9 (a) to 9 (b) are waveform diagrams showing the operation of the apparatus shown in FIG.

Figure 10 shows the prior art for tilt correction.

의 관계를 보이는 그래프이다. 11 is a radial tilt and balance value of the disc according to the present invention.

This graph shows the relationship of.

의 관계를 보이는 그래프이다.12 is a detract and balance value for a disc according to the present invention.

This graph shows the relationship of.

The present invention relates to a disc for recording and reproducing digital data, and more particularly to a disc having pits for detecting the servo error amount and the servo detrack amount.

In addition to playback-only discs such as DVD-ROM, as well as recordable discs such as DVD-RAM, the higher the recording density, the greater the deterioration of signal quality due to servo errors such as the disc's tilt and detrack. Increases. In particular, if a recordable disc has a servo error at the time of recording, the recording quality is deteriorated due to its influence, and the quality deterioration is aggravated by the servo error at the time of reproduction of the part, thereby causing a data error condition.

In a DVD-RAM disc, information is recorded in a track, and the track consists of a land track and a groove track, and the land track and the groove track are alternated every revolution of the disc. The reason why a land track and a groove track intersect on a DVD-RAM disc is a means of providing a tracking guide initially, and also can reduce crosstalk between adjacent tracks in a high density narrow track. to be.

The track is composed of sectors divided into constant lengths. As a means for enabling physical division of such sectors, a header area is formed in advance at the time of disc manufacture. The physical address of the sector is recorded in this header area.

That is, each sector is largely composed of a header area and a data area in which physical address information (hereinafter referred to as PID) is recorded.

1A shows the physical shape of the land track in a DVD-RAM disc, and FIG. 1B shows the waveform of a push-pull signal in the land track.

The header area is repeatedly arranged in a predetermined section (sector) of the track, and four PIDs (PID1 to PID4) having the same value are recorded in one header area. PID1 and PID2 are arranged a certain amount out of the center of the track, PID3 and PID4 are arranged a certain amount off in the opposite direction from the center of the track so that the laser spot 22 can accurately read the PID even if the laser spot 22 is out of the center of the track. In the land track and groove track, the arrangement of PID1, 2 and PID3, 4 is reversed. In the land track, a reproduction signal as shown in Fig. 1B can be obtained.

2A shows the physical shape of the groove track in the DVD-RAM disc, and FIG. 2B shows the waveform of the push-pull signal in the groove track.

3 is an enlarged view of the header area illustrated in FIGS. 1A to 2A. The structure of the header area is that PID1,2 and PID3,4 are arranged shifted by a fixed amount from side to side with respect to the track center, and each PID represents a vfo signal of the same frequency and a physical address of a sector for synchronization for ID detection. The ID signal is recorded. The vfo signal has a recording pattern of 4T (where T is the basic length of the recording signal).

As shown in Fig. 3, the header areas include vfo1 33 and ID1 34 (more than PID1), vfo2 35 and ID2 36 (more than PID2), vfo3 37 and ID3 38 (more than PID3). ), And vfo4 39 and ID4 40 (above PID4).

In FIG. 3, when the laser spot passes the header section of the groove track, the push-pull signal RF_pp as shown in FIG. 4A and the sum signal RF_sum as shown in FIG. 4B may be obtained. In FIG. 4A, the vfo1 signal 42 corresponds to the vfo1 signal region 33 of FIG. 3, and the vfo3 signal 43 corresponds to the vfo3 signal region 37.

FIG. 5 shows the configuration of an apparatus for obtaining the push-pull signal shown in FIG. 4A and the sum signal shown in FIG. 4B. In Fig. 5, reference numeral 50 denotes a four-part photodetector, 52 and 54 are adders, and 56 denotes a calculation unit.

The apparatus shown in FIG. 5 is a sum signal of RF_sum which is the sum signal of the signals detected by the light receiving elements A to D of the quadrature photodetector, and the sum signal of the radial pairs B and C, A and D of each light receiving element. The push-pull signal RF_pp, which is the difference signal V2-V1 between V1 and V2 and V1 and V2, is output.

Fig. 10 shows a conventional technique for tilt correction and shows a method of detecting the tilt amount by a specific pattern recorded on the track of the disc. The specific pattern coincides with the track direction and track center and is implemented in the form of a reference pit A and / or a reference pit B.

During recording / reproducing of data, the tilt information can be obtained by comparing the signal reproduced in the reference pattern as shown in FIG. 10, and the tilt correction mechanism is operated or the equalizer coefficient of the reproduction signal is changed in accordance with the obtained amount of tilt. The signal can be compensated.

Reference patterns as shown in FIG. 10 are located at any point in the disc and are useful for detecting tangential tilt (tilt in track direction).

However, in the prior art as shown in FIG. 10, the length of the reference pattern for tilt detection is too short, and another pattern is needed to detect the exact position of the tilt pattern, and the radial tilt (radius) Disadvantage of failing to detect tilt). In practical use environment, since the radial tilt is larger than the tangential tilt, it is not useful.

In order for the recording / reproducing apparatus to maintain an optimal recording / reproducing state, high-precision servo management is required, so the servo error signal needs to be managed with high precision.

However, there is a problem in that the precision of the servo error signal may vary for each disc or playback device, thereby making it difficult to precisely manage the servo.

The present invention has been devised to solve the above problems, and an object thereof is to provide a disk capable of detecting a servo error amount.

Another object of the present invention is to provide a disk capable of detecting a servo detrack amount.

Disc according to the present invention to achieve the above object

The data area is divided into sectors, each sector having a header indicating an address, the header having a first header and a second header recorded side by side from the center of the track, and the first header and the second header having the address of the sector. A disc having an address area in which is recorded and a sync signal area in which a sync signal for detecting a signal recorded in the address area is recorded,

The disk corresponds to the synchronization signals of the first and second heads such that the size ratio of the first size I1 corresponding to the first header and the second size I2 corresponding to the second header corresponds to the servo tilt error amount. It is characterized by having the feet.

Here, the size ratio is preferably determined by (I 1 -I 2) / Io (where Io is the magnitude of the mirror signal).

The first size I1 and the second size I2 are detected by the photodetector having the detection means of the radial pair and preferably detected from the difference signal RF_pp of the detection means of the radial pair.

On the other hand, the first size I1 and the second size I2 are detected by the photodetector having the detection means of the radial pair, preferably from the sum signal RF_sum of the detection means of the radial pair.

Disc according to the present invention to achieve the above another object is

The data area is divided into sectors, each sector having a header indicating an address, the header having a first header and a second header recorded side by side from the center of the track, and the first header and the second header having the address of the sector. A disc having an address area in which is recorded and a sync signal area in which a sync signal for detecting a signal recorded in the address area is recorded,

The disk corresponds to the synchronization signals of the first and second heads such that the size ratio of the first size I1 corresponding to the first header and the second size I2 corresponding to the second header corresponds to the servo detrack amount. It is characterized by having the feet.

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

For example, in the push-pull signal, the ratio of the PID1,2 and PID3,4 signals varies by up to 30% depending on the disk, and when these signals are used as reference signals for servo implementation, precise servo management and optimal recording and reproduction Difficult to maintain

The servo error detecting method of the present invention is characterized in that the servo error is detected by the ratio of the reproduction signal corresponding to the reference patterns regularly recorded on the disk. Examples of such a reference pattern include a synchronization signal recorded in the header area and a wobble signal recorded in the track direction of the disc.

First, a method of detecting servo error using a synchronization signal recorded in the header area will be described. The magnitude of the detected vfo1 signal (Ivfo1, I1 in the summary of the present invention) and the vfo3 signal when the optical axis of the laser spot is perpendicular to the signal plane of the header area, that is, when no tilt occurs in the radial direction. Although the size (Ivfo 3, I 2 in the summary of the present invention) coincides, there is a relationship in which when one of the larger ones becomes smaller when the tilt or detrack occurs.

This is because the intensity of light reflected from the signal planes of PID1, 2 and PID3, 4 arranged to be offset from each other by the tilt of the disc is different even if the light spot tracks the center of the track. When inclined toward the inner circumferential side of the disk, the intensity of the light reflected by the upper header (peak header) is greater than that reflected by the lower header (bottom header) as shown in FIGS. 1A to 2A.

Accordingly, the ratio between the magnitude Ivfo1 of the vfo1 signal and the magnitude Ivfo3 of the vfo3 signal in the reproduction signal is changed. The ratio between the magnitude (Ivfo2) of the vfo2 signal and the magnitude (Ivfo4) of the vfo4 signal in the reproduction signal also varies.

In order to detect the degree to which the size ratio varies, a signal recorded at a constant level should be used during recording. The vfo signal is suitable for this purpose because it has a constant level and a constant frequency. Also, it is easier to detect the size of vfo1,3 than vfo2,4.

Here, if the magnitudes of the synchronization signals detected in the vfo1 and vfo3 regions are Ivfo1 and Ivfo3, respectively, the balance value K is

or

는 미러 영역에서의 합신호 RF_sum의 크기이다. here,

Is the magnitude of the sum signal RF_sum in the mirror region.

Although the balance value was calculated using the magnitudes of the synchronization signals detected in the vfo1 and vfo3 regions in Equations 1 and 2, it is also possible to use the magnitudes of the synchronization signals detected in the vfo2 and vfo4 regions. However, vfo1 and vfo3 are easier to detect than vfo2 and vfo4. It is also possible to use a value obtained by the combination of the synchronization signals detected in the vfo1 and vfo2 regions and a value obtained by the combination of the synchronization signals detected in the vfo3 and vfo4 regions.

값을

라 하고, 서보 에러가 발생했을 때의

값을

이라 하면 두 값의 차이

는 다음과 같이 정의된다. If there is no servo error,

Value

When a servo error occurs

Value

Is the difference between the two values

Is defined as

의 값 및 부호에 따라 서보 에러의 방향 및 크기를 알 수 있다.In other words,

The direction and magnitude of the servo error can be known based on the value and the sign of.

는 서보 에러가 없는 상태에서 측정된 값, 기록재생 장치의 시스템 제어부에서 결정하는 디폴트값, 혹은 시스템에서 정한 기준 상태에서 측정한 값일 수 있다.here,

May be a value measured in the absence of a servo error, a default value determined by the system controller of the recording / playback apparatus, or a value measured in a reference state determined by the system.

를 연산하기 위해서

의 극성이 트랙마다 바뀌어야 한다.In the land track and groove track, the positions of PID1,2 and PID3,4 are reversed.

To compute

The polarity of must change from track to track.

Next, a method of detecting the servo error of the disc using the wobble signal will be described. Wobbles are formed on land and groove tracks on a DVD-RAM disc. The wobble is in the form of a sine wave formed on the track sidewalls.

When the disc is tilted in the radial direction, the wobble signal is inclined in the radial direction. That is, the magnitude of the wobble signal is changed between two randomly spaced points in the radial direction. Therefore, the tilt can be detected by detecting the amount of variation in the radial direction of the wobble signal.

Fig. 6 is a block diagram showing the configuration of a preferred embodiment of a servo error signal detecting apparatus suitable for a disc according to the present invention. The apparatus shown in FIG. 6 includes a reproduction signal generator 62, a header area detector 64, a first synchronous signal level detector 66, a second synchronous signal level detector 68, a balance calculator 70, and a comparator ( 72, a land / groove detector 76, a tilt adjuster 74, a polarity inverter 78, and a detrack corrector 80.

The reproduction signal generator 60 generates the push-pull signal RF_pp that is the sum signal RF_sum, the sum signals V1 and V2 of the radial pair, and the difference V2-V1 of the sum signal of the radial pair. This reproduction signal generator is composed of a four-segment photodetector having four detection means, a calculation unit, and the like as shown in FIG.

The header area detector 64 generates a header section signal (header section signal 1, header section signal 2) representing the header region from the reproduction signal. Here, the header section signal 1 is a signal representing the PID1, 2 regions, and the header section signal 2 is a signal representing the PID3, 4 regions. Since the header region has a larger envelope than the data region, a header section signal representing the header region can be obtained using an envelope detector and a comparator for detecting the envelope of the reproduction signal.

The first synchronous signal level detector 66 detects the magnitude Ivfo1 of the vfo1 signal shown in FIG. 4 in synchronization with the header section signal 1 generated by the header area detector 64. Specifically, the first enable signal enable 1 having a predetermined interval and a predetermined width is generated from the start point of the header section signal 1, and the gated reproduction signal is gated after the reproduction signal is gated by the first enable signal enalbe 1. The magnitude (Ivfo1) of the vfo1 signal is detected by detecting the peak-peak value of.

The second synchronous signal level detector 68 detects the magnitude of the vfo3 signal shown in FIG. 4 in synchronization with the header period signal 2 generated by the header area detector 64. Specifically, a second enable signal enable 2 having a predetermined interval and a predetermined width is generated from the start point of the header section signal 2, and the gated reproduction signal is gated after the reproduction signal is gated by the second enable signal enable 2. The magnitude of the vfo3 signal Ivfo3 is detected by detecting the peak-peak value of.

As shown in Equation 1, the balance calculation unit 70 measures the magnitude of the vfo1 signal detected by the first synchronous signal level detector 66 (Ivfo1) and the magnitude of the vfo3 signal detected by the second synchronous signal level detector 68. Calculate the ratio with (Ivfo3). Here, the balance calculator 70 may output the average value of the balance values obtained from several sectors consecutive in the radial direction or the tangential direction.

와 소정의 기준치

를 비교하고, 두 값의 차

를 출력한다. 여기서,

는 틸트가 없는 상태에서 측정된 값, 기록재생 장치의 시스템 제어부에서 결정하는 디폴트값, 혹은 시스템에서 정한 기준 상태에서 측정한 값일 수 있다The comparison unit 72 calculates the balance value calculated by the balance calculation unit 70 as shown in equation (3).

And the predetermined reference value

Compare and compare the two values

Outputs here,

May be a value measured in the absence of a tilt, a default value determined by the system controller of the recording / playback apparatus, or a value measured in a reference state determined by the system.

The land / groove detector 76 receives a reproduction signal and detects whether the current track is a land track or a groove track. As shown in Fig. 1B, the push-pull signal in the land track is larger in size than the PID3 and 4 in the groove track, and in the groove track, the size of the PID1 and 2 is smaller than in the PID3 and 4. The land / groove detector 80 determines the land / groove track using this.

의 극성을 반전시킨다.The polarity inversion unit 78 outputs a difference value output from the comparison unit 72 according to the result detected by the land / groove detection unit 76.

Invert the polarity of.

The balance value can be used to correct the tilt.

에 따라 디스크의 틸트를 조정한다. 차값

의 부호 및 크기는 틸트의 방향 및 크기를 나타내므로 이를 피드백 함에 의해 디스크의 틸트가 조정된다.The tilt adjustment unit 74 is a polarity inverted difference value output from the polarity inversion unit 78.

Adjust the tilt of the disc accordingly. Difference

Since the sign and magnitude of the represents the direction and magnitude of the tilt, the tilt of the disk is adjusted by feeding it back.

The balance value can be used to correct the detrack.

에 따라 디스크의 디트랙을 조정한다. 차값

의 부호 및 크기는 디트랙의 방향 및 크기를 나타내므로 이를 피드백 함에 의해 디스크의 디트랙이 보정된다.The detrack correction unit 80 is a polarity inverted difference value output from the polarity inversion unit 78.

Adjust the detrack on the disc. Difference

Since the sign and magnitude of the symbol represent the direction and magnitude of the detrack, the detrack of the disc is corrected by feeding back the detrack.

FIG. 7 is a waveform diagram showing the operation of the apparatus shown in FIG. 6. 7 (a) shows the waveform of the push-pull signal generated by the reproduction signal generator 62, and FIGS. 7 (b) and 7 (c) respectively show the header section signal 1 and the header section signal generator generated by the header section signal generator. 7 (d) and 7 (e) show the first enable signal used in the first synchronous signal level detector 66 and the second synchronous signal level detector 68, respectively. The waveforms of enable 1 and enable signal 2 are shown.

Fig. 8 is a block diagram showing the configuration of another embodiment of a servo error signal generator suitable for a disc according to the present invention. The apparatus shown in FIG. 8 is similar to the apparatus shown in FIG. 6 except for including a mirror section signal generator 86 and a mirror signal level detector 88. Therefore, the same apparatus is given the same reference numeral and the detailed description is omitted.

The mirror section signal generator 86 generates a mirror section signal representing the mirror area from the sum signal RF_sum provided from the reproduction signal generator 62. In the case of the push-pull signal RF_pp, since the mirror signal becomes zero, the mirror section signal cannot be obtained by the push-pull signal RF_pp.

Since the mirror signal has a very low envelope compared to the data region and the header region, the mirror signal may be generated by the envelope detector and the comparator.

The mirror signal level detector 88 detects the level of the mirror signal from the sum signal RF_sum based on the mirror interval signal generated by the mirror interval signal generator 86. The mirror signal level detection unit 88 generates a third enable signal enable 3 having a predetermined section and a predetermined width by the mirror section signal generated by the mirror section signal generating unit, and generates the third enable signal enable 3. The sum signal RF_sum is gated, and the peak-peak value of the gated sum signal RF_sum is detected.

을 산출한다. 여기서, 밸런스 연산부(70)는 라디얼 방향 혹은 탄젠셜 방향으로 연속된 수 개의 섹터에서 얻어지는 밸런스값의 평균치를 출력할 수도 있다. The balance calculation unit 70 may include a level Ivfo1 of the vfo1 signal detected by the first synchronous signal level detector 66, a level Ivfo3 of the vfo3 signal detected by the second synchronous signal level detector 68, and a mirror signal level detector. Balance value as shown in equation (2) by mirror signal level Io detected at (88)

To calculate. Here, the balance calculator 70 may output the average value of the balance values obtained from several sectors consecutive in the radial direction or the tangential direction.

9 (a) to 9 (b) are waveform diagrams showing the operation of the apparatus shown in FIG. 9 (a) shows the waveform of the mirror section signal output from the mirror section signal generator, and FIG. 9 (b) shows the waveform of the third enable signal enable 3.

According to the present invention, since the servo error is detected by the balance value of the synchronization signals, both the push-pull signal RF_pp, the sum signal V1 and V2 of the radial pair, or the sum signal RF_sum may be used for the servo error detection. Can be. For example, the tilt pull in the radial direction can be corrected when the push pull signal is used, and the tilt in the tangential direction can be corrected when the sum signal is used.

의 관계를 보이는 그래프이다. 도 11에 있어서 종축은 라디얼 틸트값을 나타내고, 횡축은 밸런스값

를 나타낸다. 도 11에 있어서 ▲로 표시된 그래프는 합신호 RF_sum와 수학식 1에 의한 밸런스값을 사용한 경우를 보이는 것이고, ▼로 표시된 것은 합신호 RF_sum와 수학식 2에 의한 밸런스값을 사용한 경우를 보이는 것이고, ●로 표시된 것은 푸쉬풀 신호 RF_pp와 수학식 2에 의한 밸런스값을 사용한 경우를 보이는 것이고, 그리고 ■로 표시된 것은 푸쉬풀 신호 RF_pp와 수학식 1에 의한 밸런스값을 사용한 경우를 보이는 것이다.11 is a radial tilt and balance value of the disc according to the present invention.

This graph shows the relationship of. In Fig. 11, the vertical axis represents the radial tilt value, and the horizontal axis represents the balance value.

Indicates. In FIG. 11, the graph indicated by ▲ shows a case where the sum signal RF_sum and the balance value according to Equation 1 are used, and the symbol indicated by ▼ shows a case where the sum signal RF_sum and the balance value according to Equation 2 are used. Denoted by the push-pull signal RF_pp and the balance value according to the equation (2), and denoted by ■ shows the case of using the push-pull signal RF_pp and the balance value by the equation (1).

As shown in FIG. 11, it is understood that the best showing the radial tilt is the case where the push-pull signal RF_pp and the balance value according to Equation 1 are used as indicated by. In addition, the balance value by the push-pull signal RF_pp and equation (2) is also useful as indicated by ●.

Therefore, the tilt can be determined using the push-pull signal RF_pp based on a value obtained by Equation (1) or (2).

의 관계를 보이는 그래프이다. 도 12에 있어서 종축은 디트랙량을 나타내고, 횡축은 밸런스값

를 나타낸다. 도 12에 있어서 ▲로 표시된 그래프는 합신호 RF_sum와 수학식 1에 의한 밸런스값을 사용한 경우를 보이는 것이고, ▼로 표시된 것은 합신호 RF_sum와 수학식 2에 의한 밸런스값을 사용한 경우를 보이는 것이고, ●로 표시된 것은 푸쉬풀 신호 RF_pp와 수학식 2에 의한 밸런스값을 사용한 경우를 보이는 것이고, 그리고 ■로 표시된 것은 푸쉬풀 신호 RF_pp와 수학식 1에 의한 밸런스값을 사 용한 경우를 보이는 것이다. 12 shows a detrack and balance value for a disc according to the present invention.

This graph shows the relationship of. In Fig. 12, the vertical axis represents the detrack amount, and the horizontal axis represents the balance value.

Indicates. In FIG. 12, the graph marked ▲ indicates a case where the sum signal RF_sum and the balance value according to Equation 1 are used, and the symbol denoted ▼ indicates the case where the sum signal RF_sum and the balance value according to Equation 2 are used. Indicated by using the balance value by the push-pull signal RF_pp and equation (2), and denoted by the balance of the push-pull signal RF_pp and equation (1) is used.

As shown in FIG. 11, the most affected by the de-track is when the sum signal RF_sum and the balance value according to Equation 1 are used (graph denoted by ▲) and the least affected is the push-pull signal RF_pp and Equation 1 It can be seen that the balance value by is used (marked with ■).

Therefore, the detrack may be determined using the sum signal RF_sum based on a value obtained by Equation 1 or Equation 2.

As can be seen from FIG. 11 to FIG. 12, it is understood that the tilt amount is most efficiently detected when the push-pull signal RF_pp and the balance value according to Equation 1 are used.

의 값은 일정한 수준을 유지하도록 관리되는 것이 바람직하다.The quality of the servo error signal varies depending on the quality of the disc and the conditions of the system. However, if the value is not limited to some extent, the PID cannot be recognized or stable servo management becomes difficult. So for a disc

The value of is preferably managed to maintain a constant level.

의 값을 ±0.1로 제한하는 것을 제안한다. 이 값은 규정된 틸트량 ±0.35。를 주었을 때 PID를 정상적으로 재생하기 위하여 요구되는 것이다. 또한, 트랙 제어의 공차 범위도 고려된다.Accordingly, in the present invention

It is suggested to limit the value of to ± 0.1. This value is required to regenerate the PID normally when the specified tilt amount is ± 0.35 °. In addition, the tolerance range of the track control is also considered.

의 값을 소정치 이하로 제한할 필요가 있다. 재생할 때의 서보 품질이 엄격하게 관리 되지 않을 경우 PID정보를 얻지 못하게 된다.In addition, even for a disc reproducing apparatus,

It is necessary to limit the value of to below a predetermined value. If the servo quality during playback is not strictly controlled, PID information will not be obtained.

의 값을 ±0.1로 제한하는 것을 제안한다.Therefore, in the present invention, in the servo operation of the reproducing apparatus,

It is suggested to limit the value of to ± 0.1.

According to the disc according to the present invention, the recording and reproducing apparatus maintains stable servo control by detecting the servo error amount and the servo detrack amount by the pits recorded on the disc.

Claims (8)

The data area is divided into sectors, each sector having a header indicating an address, the header having a first header and a second header recorded side by side from the center of the track, and the first header and the second header having the address of the sector. A disc having an address area in which is recorded and a sync signal area in which a sync signal for detecting a signal recorded in the address area is recorded, The disk corresponds to the synchronization signals of the first and second heads such that the size ratio of the first size I1 corresponding to the first header and the second size I2 corresponding to the second header corresponds to the servo tilt error amount. And a disc having pits. The disk of claim 1, wherein the size ratio is determined by (I 1 -I 2) / Io, where Io is the size of a mirror signal. The method of claim 1, wherein the first size I1 and the second size I2 are detected by a photodetector having radial pair detection means, and detected from a difference signal RF_pp of the detection means of the radial pair. disk. The method of claim 1, wherein the first size I1 and the second size I2 are detected by a photodetector having radial pair detection means, and detected from a sum signal RF_sum of the detection means of the radial pair. disk. The data area is divided into sectors, each sector having a header indicating an address, the header having a first header and a second header recorded side by side from the center of the track, and the first header and the second header having the address of the sector. A disc having an address area in which is recorded and a sync signal area in which a sync signal for detecting a signal recorded in the address area is recorded, The disk corresponds to the synchronization signals of the first and second heads such that the size ratio of the first size I1 corresponding to the first header and the second size I2 corresponding to the second header corresponds to the servo detrack amount. And a disc having pits. 6. The disk of claim 5, wherein the size ratio is determined by (I1-I2) / Io, where Io is the size of the mirror signal. 6. The method of claim 5, wherein the first size I1 and the second size I2 are detected by a photodetector having detection means of the radial pair, and are detected from the difference signal RF_pp of the detection means of the radial pair. disk. 6. The method of claim 5, wherein the first size I1 and the second size I2 are detected by a photodetector having detection means of a radial pair, and are detected from a sum signal RF_sum of detection means of the radial pair. disk.

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