KR100491233B1 - Optical disc, optical disc device, and method for recording an optical disc - Google Patents

Abstract

In the optical disc according to the present invention, a sector is formed sequentially by a first gap field, a first guard data recording field, a data recording field consisting of a synchronization signal and user data, a second guard data recording field and a second gap field. The lengths of the first and second gap fields and the lengths of the first and second guard data recording fields are randomly changed each time the recording is performed, and the amount of change of the first and second gap fields is changed to the first and second guard data. It is set smaller than the amount of change in the recording field, so that optical disc medium deterioration of all sectors and all marks due to repetitive recording can be suppressed.

Description

Optical discs, optical disc devices, and optical disc recording methods {OPTICAL DISC, OPTICAL DISC DEVICE, AND METHOD FOR RECORDING AN OPTICAL DISC}

The present invention relates to an optical disc, an optical disc apparatus and an optical disc recording method for recording a digital signal and reproducing the digital signal in a sector unit of the optical disc.

In the prior art description EP-A-0718831, a recording and reproducing method and apparatus for an overwritable phase change type optical disc are known. According to the disclosure of this document, the rewrite repeatability of the optical disc is extended by randomly writing either unconverted write data or converted write data. Deterioration due to repetitive rewriting at the start and end of recording is achieved by recording a synchronization signal between before and after the write data and / or dummy data in a manner such that thermal stress does not easily occur. Suppressed. The recording end position can be precisely determined by detecting a pause to stop recording. EP-A-0814463 is an identification number detector for identifying a recording state of an overwritten sector, and a dog for writing in accordance with the recording state. An apparatus for writing to and reading from an overwritable optical disc comprising a delay time control circuit for setting a change range of a viewpoint. A method for writing and reading in an overwritable optical recording medium having a sector format disclosed in this document includes modulating the write data to produce a modulated data signal in accordance with a recording pattern of the optical recording medium; Selecting a second write timing, randomly changing a starting point for writing a modulated data signal in a sector when the first write timing is selected within a first change range, and selecting the second write timing And randomly varying a starting point for writing a modulated data signal in a sector within the second change range that is greater than the first change range. To start.

Optical discs are now widely distributed as read-only recording media such as compact discs (CDs) used in audio and video, and rewritable recording media such as mini discs (MDs). In addition, as an external memory device of a computer, rewritable 3.5-inch magneto-optical discs and 5-inch phase change optical discs (PD) have become popular.

In the future, as a multimedia recording medium, digital video discs (DVDs) using phase change optical discs are becoming popular. One of the advantages of the phase change optical disk is that only one laser beam is needed as the recording means to overwrite the information signal. That is, if the modulated laser output is irradiated to the recorded information track as a function of switching the information signal between the recording level and the erasing level, a new signal can be recorded while erasing the existing information signal.

The format structure of such an optical disc will be described with reference to FIG. In Fig. 18, reference numeral 1 denotes an optical disc, reference numeral 2 denotes a track on the optical disc 1, and reference numeral 3 denotes a sector obtained by dividing the track into a plurality of fields. Each sector 3 has a header field 4 containing track and sector address information, a gap field 7 without a recorded signal, a data recording field 5 for recording user data, and incorrect results of motor rotation. It consists of a buffer field 6 for absorbing.

The header field 4 is usually in the form of a prepit and is not used for writing. Reference numeral 4a denotes a synchronization signal VFO for synchronization, reference numeral 4b denotes an address mark for detecting the header field as a special recording pattern that does not appear on the modulation pattern, and reference numeral 4c denotes address information for the physical position of the sector. A field containing a Physical Identification Address (PID) with reference numeral 4d is ID Error Detection (IED) for detecting an address error. The header field consisting of blocks 4a to 4d may be composed of a plurality of header fields to increase reliability.

The data record field 5 consists of a synchronization signal VFO 5b and user data 5c for synchronization.

Hereinafter, with reference to FIG. 19, an optical disk apparatus for recording and reproducing signals by a recordable optical disk will be described. In Fig. 19, reference numeral 1 denotes an optical disc, reference numeral 10 denotes an optical head for recording and reproducing a signal on a track of the optical disc 1, reference numeral 11 denotes an optical beam of a semiconductor laser on a track of the optical disc ( Servo control circuit for focusing the optical beam, reference numeral 12 denotes a laser driving circuit for controlling the light output of the semiconductor laser, reference numeral 13 denotes a digital form in a form suitable for recording coded data. A data modulation circuit and a reference numeral 14 for modulating the data is a VFO generating circuit for generating a VFO as a synchronous signal. Reference numeral 15 denotes an encoding circuit for performing error detection encoding of recorded data, reference numeral 16 denotes a write control circuit for controlling recording timing, reference numeral 17 denotes an address detection circuit for detecting an address signal from a reproduced signal, Reference numeral 18 is a system control circuit for controlling the operation of the entire optical disk device and other related circuits composed of microprocessors, and reference numeral 19 is data to be written.

The data encoded by the encoding circuit 15 is modulated by the data modulation circuit 13 and output from the data modulation circuit 13 as modulated data. The synchronizing signal VFO generated by the VFO generating circuit 14 is added to the beginning of this modulated data, transmitted to the laser drive circuit 12, and recorded on the optical disk 1.

However, in such a rewritable light-operative optical disc, the number of repetitive recordings is limited because the recording medium deteriorates due to the thermal load upon repeated light exposure. In general, such deterioration phenomena tends to become more prevalent in the deterioration area as the number of repeated recordings increases. Degradation can be divided into two types.

(1) Degradation phenomenon in each sector occurring at the beginning end (recording start position) and terminating end (recording end portion) of the recording field of the sector as the recording is repeated in the sector.

(2) Deterioration phenomenon in each mark occurring in the mark area by repeatedly recording mark rows of the same pattern at the same position of the sector.

First, in the phenomenon of deterioration in each sector, as recording is repeated, deterioration gradually occurs at the recording foils at the leading end and the end of the recording field in the sector, and this defect (the associated laser on the optical disk) It extends from the front end to the forward direction) and from the end to the front of the sector (for the reverse direction of the associated laser travel direction on the optical disc).

This phenomenon is considered to occur because the phenomenon of movement of the recording foil substance in the track direction occurs when the recording foil is in the fused state. For example, by moving the recording foil material in the forward direction of the sector, dissolution and solidification are repeated a plurality of times, whereby the recording foil material is accumulated at the portion of the recording start point at which the thermal load of the recording foil suddenly changes, This recording foil material is reduced in thickness at the recording endpoint portion. As a result, the film thickness between the recording start point and the end point becomes non-uniform, so that the thermal or optical properties deteriorate, the film peels off, and / or the quality of the reproduction signal at the data tip or end deteriorates, so that the correct It interferes with the recording of information and the reproduction of information.

Next, in the deterioration phenomenon at each mark, as recording is repeated, a defect occurs in the recording foil when recording the same pattern, and this defect extends to the front and rear of the mark portion.

That is, when the same data is repeatedly recorded in the same sector, dissolution and solidification are repeated a plurality of times in some areas, while other areas are not dissolved at all.

In general, when rewriting data recorded on an optical disc, the data is rewritten in sector units. Therefore, if there is a change in information in a part of the sector, the entire sector is rewritten. In the TOC (Table of Contents) field or the directory field in which information corresponding to the table of contents of the information recorded on the disk is recorded, particularly, similar data is frequently recorded repeatedly and the rewriting frequency is high. Also in the normal data sector, the same data is repeatedly recorded in the synchronization signal section VFO or the like, and in this case, the above-described degradation phenomenon occurs. As a result, in the boundary region between the repeatedly dissolved and solidified portion and the portion that is not dissolved at all, there is a variation in the film thickness of the recorded film, resulting in deterioration of the thermal and optical properties and deterioration in the quality of the reproduction signal of this portion. Prevents recording and reproduction of normal information.

Summary and purpose of the invention

The present invention has been made to solve the above problem, and relates to an optical disc for recording data and reproducing data in sector units. It is an object of the present invention to reduce the degradation of the recording foil of an optical disc in all sectors and all marks due to repeated recording, simplify the associated signal processing system, and suppress the degradation phenomenon for accurate recording and reproduction of information. It is possible to provide an optical disc, an optical disc apparatus, and a recording method of the optical disc.

In order to achieve these and other objects, according to the first aspect of the optical disk of the present invention, a header field including a sector identification signal and a data recording field including a synchronization signal are assigned to each of a plurality of sectors that divide a track. A guard data record field for recording specific guard data is provided between the header field and the data record field.

By this guard data recording field, the synchronization signal can be protected from degradation of the medium due to repeated recording.

According to the second aspect of the optical disk of the present invention, the guard data of the guard data recording field is the same as the recording pattern of the synchronization signal field, and the phase of the recording pattern is near the boundary of the guard data recording field and the synchronization signal field. Continues.

As a result, the guard data recording field can be used substantially as a synchronization signal field, and the stability of synchronism acquisition because the lock-in range of synchronization can be further extended than the synchronization signal field. Can be improved in view of medium degradation due to repetitive recording.

According to the third aspect of the optical disk of the present invention, the recording portion of the guard data recording field changes randomly every time recording.

As a result, since the mark position recorded on the recording medium by repeatedly recording the guard data recording field for recording the same signal pattern is shifted randomly every time recording, deterioration of the recording medium can be prevented. have.

According to a fourth aspect of the optical disk of the present invention, the sector structure is sequentially a data recording including a first gap field having no signal, a first guard data recording field for recording guard data, a synchronization signal and user data. Field, a second guard data record field and a second gap field, wherein the total length of the first and second gap field is constant, the total length of the first and second guard data record field is constant, In recording, the lengths of the first gap field and the first guard data recording field change randomly at the time of recording, and the change amount of the first gap field is set smaller than the change amount of the first guard data recording field.

Accordingly, since the first and second gap fields and the first and second guard data recording fields change randomly at the time of recording, medium degradation due to repetitive recording in all sectors and all marks can be suppressed.

In addition to the fourth aspect, according to the fifth aspect of the optical disk of the present invention, the resolution of the variation amount of the first gap field is in channel bit units, and the resolution of the variation amount in the first guard data recording area is in bytes. (byte unit).

Thus, while easily maintaining the realization of data processing on the signal processing system, medium degradation due to repetitive recording in all sectors and all marks can be suppressed.

In addition to the fourth aspect, according to the sixth aspect of the optical disk of the present invention, the signal polarity of the guard data and the data recording field data change randomly every time they are recorded.

As a result, even with a limited amount of random shift, medium degradation in all sectors and all marks can be suppressed.

As mentioned below, the optical disk apparatus of the present invention can include means for recording to and reproducing from the optical disk, thereby suppressing media degradation due to repetitive recording in all sectors and all marks.

Since the optical disc recording method of the present invention includes a method for recording on these optical discs, it is possible to suppress the deterioration of the medium due to repetitive recording in all sectors or all marks.

1 is a diagram showing a format structure of an optical disk according to Embodiment 1 of the present invention;

2 (a) to 2 (c) are diagrams showing deterioration of a recording medium and a synchronization signal field VFO at a recording start point in repetitive recording;

3 is a block diagram of an optical disc according to Embodiment 2 of the present invention for recording to and reproducing from an optical disc having a guard data recording field;

4A to 4D are diagrams showing a synchronization signal portion in which the guard data of the guard data recording field has a pattern different from that of the synchronization signal VFO;

5A to 5D are diagrams showing a synchronization signal portion of an optical disc of Embodiment 3 in which the guard data of the guard data recording field has the same pattern as the synchronization signal VFO;

Fig. 6 is a block diagram of an optical disc according to the fourth embodiment for recording and reproducing the recording pattern of the guard data recording field in the same way as the synchronization signal field VFO;

7 is a flowchart for explaining an optical disk recording method according to Embodiment 5 in which the recording pattern of the guard data recording field is recorded and reproduced in the same way as the synchronization signal field VFO;

8A to 8D are diagrams showing the state of a sector of an optical disc according to the sixth embodiment for randomly changing each time a sector recorder is recorded;

Fig. 9 is a block diagram of the optical disk apparatus according to the seventh embodiment for recording a signal on the optical disk and reproducing the signal from the optical disk by changing randomly every time the sector recording unit is recorded;

FIG. 10 is a diagram showing a format of an optical disc for recording and reproduction by randomly changing each time recording portions of the first and second gap fields and the first and second guard data recording fields are recorded in all sectors; FIG.

Fig. 11 shows the optical disk apparatus according to the eighth embodiment for recording and reproducing by randomly changing each time the recording portions of the first and second gap fields and the first and second guard data recording fields are recorded in all sectors. Block Diagram,

12 is a block diagram illustrating an example of a second random change circuit;

13 is a flowchart for explaining an optical disc recording method according to the eighth embodiment;

14A to 14D are diagrams showing modes of sectors when the first and second gap fields and the first and second guard data recording fields are randomly changed;

15 (a) to (b) are diagrams showing a deterioration area of a sector when the first and second gap fields and the first and second guard data recording fields are randomly changed;

16A to 16C are diagrams for explaining the polarity and recording stage of a recording signal on an actual optical disk;

17 is a result graph shown to explain the result of the random shift according to the present invention;

18 is a format diagram of a conventional recordable optical disc;

Fig. 19 is a block diagram of a conventional recordable optical disc device.

Embodiment of the Invention

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Example 1)

1 is a diagram showing the format structure of an optical disk according to the first embodiment of the present invention. The description of the parts shown in the format structure of FIG. 18 related to the prior art will be omitted.

Compared with the prior art, the added part and the modified part are guard data recording fields 100 for recording the guard data, which are provided between the header field 4 and the data recording field 5. The guard data record field 100 is provided after the gap field 7 and immediately before the data record field 5. Since the signal is not recorded in the gap field 7, the recording of the signal in the sector starts in the guard data recording field 100.

Referring to Figs. 2 (a) to 2 (c), in the optical disk having the format structure of Fig. 1, the relationship between the degradation of the recording medium at the recording start point and the synchronization signal field VFO at the time of repeated recording will be described. do.

2 (a) to 2 (c) show the degradation modes of the recording medium adjacent to the recording start point of the data recording field 5, and FIG. 2 (a) shows only one repetition, and FIG. 2 (b) Represents 50,000 repetitions, and FIG. 2 (c) represents 100,000 repetitions.

In the initial stage of one repetition of Fig. 2A, since the guard data recording field 100 at the recording start point of the sector is free from medium degradation, there is no problem. Thus, in the initial state, the interval of the guard data recording field is assumed to be T ₁ , and the interval of the synchronization signal field VFO is assumed to be T ₂ .

As shown in Fig. 2 (b), after 50,000 repetitions, the medium deterioration indicated by the reference numeral 30 of the TC ₁ section occurs at the beginning of the guard data recording field 100, and the guard data recording field occurs. 100 is shortened by the TC ₁ section, which is the length of the medium degradation 30, to be T4. However, when media degradation occurs, the guard data recording field 100 in which the guard data is recorded is shortened by that length. The synchronization signal field VFO required for synchronization is completely free from medium degradation 30 so that the synchronization interval T ₂ remains the same as the initial state. Thus, as in the initial state, stable synchronization acquisition is realized.

As shown in Fig. 2C, after 100,000 repetitions, the medium deterioration 30 at the head of the guard data recording field 100 is extended to the TC ₂ section. As a result, the guard data recording field 100 is shorter with T ₅ . However, only the guard data recording field in which the guard data is recorded is shortened by that length, and the synchronization signal field VFO necessary for synchronization is completely freed from the medium degradation 30, so that the synchronization section T _{2 is the} same as in the initial state. Remains. Thus, as in the initial state, stable synchronization acquisition is realized.

As described, according to this embodiment, by providing the guard data recording field 100 for recording the guard data between the header field and the data recording field including the synchronization signal, media degradation caused by repeating recording Since the synchronization signal field is prevented from being shortened, the synchronization acquisition is stabilized.

(Example 2)

3, an optical disk apparatus according to Embodiment 2 of the present invention for recording and reproducing on an optical disk having a guard data recording field at the head of a sector will be described. The description of the parts already described in the optical disk device of FIG. 19 related to the conventional technology will be omitted.

Added to the prior art are the guard data generation circuit 200 and the first write control circuit 201. The guard data generation circuit 200 generates specific guard data. First, the guard data of the guard data generating circuit 200 is provided, and then the synchronous signal VFO of the synchronous signal VFO generating circuit 14 is added, followed by the modulated data of the data modulation circuit 13. This data timing is controlled by the first write control circuit 201. The combined guard data, synchronization signal VFO and modulated data are provided to the laser drive circuit 12 and recorded on the optical disk.

According to the present embodiment, as described below, in addition to the configuration of the conventional optical disk apparatus, a guard data generating circuit 200 and a first recording control apparatus 201 for generating guard data are provided, and a header field is provided. By recording the guard data of the guard data recording field 100 between (4) and the synchronization signal field VFO at the beginning of the data recording field 5, the synchronization signal is protected from medium degradation caused by repeating the recording. Thus, an optical disk device that is stable in synchronism acquisition is realized.

(Example 3)

In the optical disc having the format structure according to the third embodiment of the present invention, FIGS. 4A to 4D and 5A to 5D show deterioration of a recording medium at a recording start point during repeated recording. A relationship between synchronization sections of a synchronization signal field VFO is shown. In the optical disc of Embodiment 3, the recording pattern of the guard data in the guard data recording field is the same as the recording pattern of the synchronization signal field VFO. Further, at the boundary between the guard data recording field and the synchronization signal field, the phase of the recording pattern is coincident so as not to cause discontinuation.

First, in Figs. 4A to 4D, the guard data in the guard data recording field is different from the recording pattern of the synchronization signal field VFO. Fig. 4 (a) shows the data recording field after one repetition, Fig. 4 (b) shows the fixed range during synchronization, Fig. 4 (c) shows the data recording field after 100,000 repetitions, and Fig. 4 (d) ) Represents a fixed range at synchronization after 100,000 iterations.

In the initial state after one repetition, the guard data recording field 100 at the recording start point of the data recording field 5 is free from medium deterioration. The section of the guard data recording field in the initial state is assumed to be T ₁ , and the section of the synchronization signal field VFO is assumed to be T ₂ .

After one repetition, the fixed range of the synchronization 300 becomes the T ₂ section of the synchronization signal field VFO.

In the case after 100,000 repetitions shown in FIG. 4C, the medium deterioration 30 occurs during the TC ₂ section at the head of the guard data recording area 100. As a result, the guard data recording field 100 is shortened to a T ₅ section. However, only the guard data recording field in which the guard data is recorded is shortened, and the synchronization signal field VFO necessary for synchronization is not affected at all by the medium degradation 30.

As shown in FIG. 4 (d), the fixed range at the time of synchronization 300 after 100,000 repetitions remains T ₂ as in the initial state after one repetition. Thus, as in the initial state, acquisition of stable synchronization is realized.

In Figs. 5A to 5D, the guard data of the guard data recording field is the same as the recording pattern of the synchronization signal field VFO. Further, the images of the recording pattern are coincident so as not to be discontinuous at the boundary between the guard data recording field and the synchronization signal field. Fig. 5 (a) shows the data recording field after one repetition, Fig. 5 (b) shows the fixed range during synchronization, Fig. 5 (c) shows the data recording field after 100,000 repetitions, and Fig. 5 (d ) Represents a fixed range at synchronization after 100,000 iterations.

As shown in Fig. 5A, in the initial state after one repetition, the guard data recording field 100 at the recording start point of the data recording field 5 is free from medium deterioration. The interval of the guard data recording field in the initial state is assumed to be T ₁ , and the interval of the synchronization signal field VFO is assumed to be T ₂ .

Therefore, after one iteration, the fixed range of the synchronization 400 maintains the continuity in the same recording pattern as the signal in the guard data recording field as in the synchronization signal field VFO, and thus the T ₁ section of the guard data recording field and the synchronization signal field VFO. Is the sum of T ₂ intervals of T ₁ + T ₂ . Compared to T ₂ , which is the fixed range of the synchronization 300 in the recording pattern, the signal of the guard data recording field is different from the synchronization signal field VFO described in FIGS. 4A to 4D, and the fixed range in this embodiment. Extends to the T ₁ interval portion of the guard data record field.

In the case after 100,000 repetitions shown in FIG. 5C, the medium deterioration 30 occurs at the head of the guard data recording area 100 during the TC ₂ period. Accordingly, the guard data recording field 100 is shortened to the T ₅ section. However, since only the guard data recording field in which the guard data is recorded is shortened, the synchronization signal field VFO necessary for synchronization is not affected at all by the medium degradation 30.

Even after 100,000 repeated shown in 5 (d), fixing a range of sync 400 is a sum T ₅ + T ₂ of T ₅ interval and a synchronization signal field VFO T ₂ period of the guard data recording field (100). Compared to T ₂ , which is a fixed range of synchronization 300 in the recording pattern, the signal of the guard data recording field is different from the sync signal field VFO described in FIGS. 4A to 4D, and the fixed range is the guard data recording field. It extends to the section of.

Thus, even after 100,000 repetitions, even if medium degradation occurs at the recording start point, the fixed range of synchronization is longer by the T ₅ section portion of the guard data recording field than the T ₂ section of the initial synchronization signal field VFO. As a result, the stability and reliability of phase locked loop (PLL) synchronization is improved.

As will be explained below, according to the present embodiment, the guard data recording field 100 provided between the header field 4 and the data recording field of the optical disc is provided with guard data having the same recording pattern as the synchronization signal field VFO. By doing so, the continuity is maintained, and the fixed range of synchronization can be extended behind the synchronization signal field VFO, so that if media degradation due to repetitive recording occurs, the stability and reliability of synchronization acquisition can still be maintained.

(Example 4)

Hereinafter, an optical disk apparatus according to Embodiment 4 of the present invention will be described with reference to FIG. 6. In this embodiment, recording and reproduction are performed by providing a recording pattern guard data recording field at the head of the sector, the guard data being the same as in the synchronization signal field VFO. The description of the parts already described in the optical disk device of FIG. 19 associated with the conventional technology will be omitted.

Circuits added to the prior art are the VFO guard data generation circuit 500 and the first write control circuit 201. The VFO guard data generation circuit 500 generates the same write pattern as the guard data write field 100 and the sync signal field VFO. The first write control circuit 201 generates continuous gate timing so as not to cause any discontinuity between the guard data write field 100 and the sync signal field 5b. As a result, in the guard data recording field 100 and the synchronization signal field 5b, the same recording pattern for synchronization is generated continuously.

First, a write pattern is generated from the VFO guard data generation circuit 500. Then, the modulated data from the data modulation circuit 13 is placed after the recording pattern. This data timing is controlled by the first write control circuit 201. The combined data is subsequently provided to the laser drive circuit 12 at the stage and recorded on the optical disc.

According to this embodiment, as will be described below, the VFO guard data generation circuit 500 for generating a common write pattern to the guard data write field 100 and the synchronization signal field VFO and the first write control circuit 201 is provided. By adding to the conventional optical disk device, a recording pattern for synchronization is recorded between the header field 4 and the synchronization signal field VFO, and thus, since the fixed range of synchronization extends to the rear of the interval of the synchronization signal field VFO, An optical disk device that can improve the reliability and stability of synchronizing acquisition can be realized in view of medium degradation caused by repetitive recording.

(Example 5)

Fig. 7 is a step by step description of a recording method for an optical disc according to Embodiment 5 of the present invention for recording and reproducing the same recording pattern of the sync signal field VFO in the guard data recording field at the head of a sector.

In step 210, the optical disk device reads the address information of the optical disk by a command from the host system of the address detecting circuit 17 (see, for example, FIG. 6). The system control circuit 18 checks whether the address of the sector has been recorded.

In step 211, the recorded data is encoded by the encoding circuit 15, modulated by the data modulation circuit 13, and the data modulation circuit 13 outputs the modulated data.

In step 212, a synchronization signal VFO for synchronization is added by the VFO generation circuit 14 to the beginning of the modulated data.

In step 213, guard data for suppressing medium deterioration is added by the guard data generation circuit 20 to the head of the synchronization signal VFO.

Thereafter, in step 214, the write data generated in steps 211, 212, and 213 are controlled by the first write control circuit 201 and recorded in the appropriate order in the corresponding sectors recorded. Specifically, the guard data is recorded in the guard data recording field, and the synchronization signal VFO and user data are recorded in the data recording field.

By these steps, data can be recorded on the optical disc and reproduced from the optical disc in the recording format shown in FIG.

(Example 6)

Hereinafter, with reference to Figs. 8A to 8D, the optical disc according to the sixth embodiment of the present invention will be described next, and the recording section of the guard recording field is randomly changed each time it is recorded.

8 (a) to (d), various recording sections of the guard data recording field 100 of each sector 1, 2, 3 and 4 are shown.

In Fig. 8A, the recording section of the guard data recording field 100, which is related to the sector 1, is T _1, and the interval of the subsequent synchronization signal field VFO is T ₂ . The combined section of the guard data recording field 100 and the synchronization signal field VFO is T ₁ + T ₂ .

In Fig. 8 (b), the recording section of the guard data recording field 100, which relates to the sector 2 following the sector 1, is extended by the dT section compared to the sector 1 to be T ₁ + dT. The combined section of the guard data recording field 100 and the synchronization signal field VFO is T ₁ + T ₂ + dT. As the guard data record field 100 extends by dT, it can be understood that the end of the data record field is shifted backwards by the same amount.

In Fig. 8C, the recording section of the guard data recording field 100, which relates to the sector 3 following the sector 2, extends by 2dT sections compared to the sector 1, and becomes T ₁ + 2dT. Therefore, the coupling period between the guard data recording field 100 and the synchronization signal field VFO is T ₁ + T ₂ + 2dT. Just as the guard data record field 100 extends by 2dT, the end of the data record field is likewise shifted backward by the same amount.

In FIG. 8 (d), the recording period of the guard data recording field, which is related to the sector 4 following the sector 3, is T ₁ as in the sector ₁ . Therefore, the coupling period between the guard data recording field 100 and the synchronization signal field VFO is again T ₁ + T ₂ .

According to this scheme, the recording section of the guard data recording field 100 changes randomly every time recording at a time resolution of dT in all sectors. The number of bits for randomly changing this time resolution dT is appropriately determined by the system configuration. A detailed example of a phase change optical disk will now be described.

When the channel bit frequency is 29.18 MHz, assuming that one byte of data corresponds to 16 channel bits during the period t = 34.27 nsec of one bit of the channel bit, 16t = 548 nsec becomes one byte in the data. The line velocity is about 6 m / s. The guard data recording field 100 of section T ₁ = 20 bytes is changed by eight bytes of 0 to 7 bytes by 20 bytes + K (K = 0 to 7) at a resolution of 1 byte unit. By this random time shift, since the starting point of the synchronization signal field VFO can be changed at random, recording degradation due to the same recording pattern can be prevented. The recording section of the guard data recording field is 20 bytes x 6 m / s x 548 nsec = 66 mu m.

Although not shown in Figs. 8A to 8D, a random time shift is also preferably given to the guard data recording field 100, and the recording pattern is the same as the synchronization signal field VFO. As a result, the length of the gap field 7 changes randomly every time recording. For example, a gap field section of 10 bytes (34 μm) is changed in 16 ways corresponding to 0 to 15 channel bits at a resolution of one channel bit t = 34.27 nsec. This is described later in detail.

When using such a random time shift, according to the relationship between the number of recordings and the deterioration interval of the guard data recording field 100, the deterioration interval is 7 mu m at 20,000 recording repetitions and 10 mu m at 50,000 repetitions. , 33 µm when repeated 100,000 times.

As a result of the random time shift, the deterioration of the recording section of the guard data recording field 100 is suppressed to 33 mu m even if the recording is repeated 100,000 times. If the recording section of the guard data recording field 100 is set to 66 占 퐉, since the deterioration of the recording section does not extend to the synchronization signal field VFO even after 100,000 recordings, stable synchronization acquisition is maintained.

In this regard, since the recording pattern of the guard data recording area is the same as the synchronization signal VFO, the channel bits are repeated as 00010001, and alternating repetition of mark and space in the length of four channel bits in the recording medium can be used.

(Example 7)

Hereinafter, an optical disk apparatus according to Embodiment 6 of the present invention will be described with reference to FIG. 9. Here, recording is performed on the optical disk and reproduced while randomly changing the recording section of the guard data recording field each time recording. The description of the parts already described with respect to the optical disk device of FIG. 19 related to the conventional technology will be omitted.

Circuits added to the prior art are the guard data generation circuit 200, the first write control circuit 201, and the first random change circuit 220. First, the guard data is generated from the guard data generation circuit 200. Then, the synchronization signal VFO from the synchronization signal VFO generation circuit 14 is placed next to the guard data, and then the modulation data from the data modulation circuit 13 is next placed. The first random change circuit 220 changes the write section of the guard data recording area by 20 bytes + K (K varies randomly from 0 to 7) at a resolution of 1 byte. While the recording period of the guard data recording field changes randomly, the timing of the combined guard data, the synchronization signal VFO, and the modulated data are controlled by the first write control circuit 12, and these write signals are lasered at a later stage. It is provided to the drive circuit 12, and is written to the sector on the optical disc during random changes every time recording.

As described below, according to the present embodiment, the guard data generation circuit 200, the first write control circuit 201, and the first random change circuit 220 for generating guard data in the conventional optical disk device are described. By adding, the recording start point changes randomly every time recording, and therefore signal degradation of the synchronization signal VFO and user data due to repetitive recording can be suppressed.

(Example 8)

10 records and reproduces by randomly changing the lengths of the first and second gap fields and the first and second guard data recording fields each time the first gap field is smaller than the change amount of the first guard data recording field. The format structure of an optical disk according to Embodiment 8 of the present invention for setting the amount of change of? Description will be omitted for the parts already described in the format structure shown in FIG. 18 related to the conventional technology.

Added to the prior art are the mirror field 270 used to adjust the servo signal, the first gap field 271 which is the period without signal, the first guard data recording field 272 for recording the guard data, and subsequent A second guard data record field 273 for recording the guard data in the data record field 5 and a second gap field 274 which is a section without a signal.

Hereinafter, the recording sections of the first and second gap fields 271 and 274 and the first and second guard data recording fields 272 and 273 change randomly every time they are recorded.

11 records on the optical disc and reproduces from the optical disc by randomly changing the lengths of the first and second gap fields and the first and second guard data recording fields each time recording is performed. An optical disk apparatus for setting the change amount of the first gap field smaller than the change amount is shown. The same parts that have already been described with respect to the optical disk device of FIG. 19 in relation to the prior art will be omitted.

Circuits added to the prior art apparatus are the guard data generation circuit 200, the second write control circuit 230, the second random change circuit 240, and the polarity conversion circuit 250. The guard data generation circuit 200 generates specific guard data. First, the guard data is generated from the guard data generation circuit 200. Then, the synchronization signal VFO from the synchronization signal VFO generation circuit 14 is placed next to the guard data, and then the modulation data from the data modulation circuit 13 is next placed. The second random change circuit 240 randomly changes the write intervals of the first and second gap fields. For example, the first gap field is changed by 10 bytes + J / 16 (J varies randomly from 0 to 15) each time a write is made. Since the resolution of the change amount is J / 16, one byte consists of 16 bits per channel bit. The second gap field is changed by 25 bytes-J / 16 (J varies randomly from 0 to 15) each time a write is made. Accordingly, the total length of the recording section of the first gap field and the recording section of the second gap field is kept constant. Further, the second random change circuit 240 randomly changes the write intervals of the first and second guard data write fields. For example, the first guard data record field is changed by 20 bytes + K (K varies randomly from 0 to 7), which is a resolution of 1 byte. Similarly, the second guard data record field is changed by 55 bytes-K (K is randomly changed from 0 to 7), which is a resolution of 1 byte. Hereinafter, the total length of the recording section of the first guard data recording field and the recording section of the second guard data recording field is also kept constant.

While randomly changing the recording intervals of the first and second gap fields and the first and second guard data recording fields, the combined guard data, the synchronization signal VFO, and the modulated data are controlled by the second write control circuit 230. . The write signal composed of these signals passes through the polarity conversion circuit 250 at a later stage, and the polarity of the write signal is randomly changed in the sector section every time the recording is performed. The write signal from the polarity conversion circuit 250 is provided to the laser drive circuit 12, the write intervals of the first and second gap fields and the write intervals of the first and second guard data write fields are changed randomly, The polarity of the recording signal is changed randomly and recorded in the sector on the optical disc.

Hereinafter, an example of the structure of the second random change circuit 240 will be described with reference to FIG. 12. In FIG. 12, the random change circuit 701 consists of 13 stages of the shift register 704 and is designed to receive a clock 703 and a random update command 704. By the command of the random update command 704, the single polarity and the amount of change are the one bit signal 705 for determining the polarity of the write signal, and the four bit signal 706 for determining the amount of change in the first and second gap fields. And a 3-bit signal 707 for determining the amount of change in the first and second guard data recording fields.

Fig. 13 is a flowchart showing an operation for rewriting recording information by this optical disk device.

In addition, with reference to FIG. 11, the operation according to the flowchart of FIG. 13 is demonstrated below.

In step 261, the optical disc reads the address information of the optical disc by a command from the host system of the address detection circuit 17. The system control circuit 18 checks whether the address of the sector has been recorded.

In step 262, the recorded data is encoded in the encoding circuit 15, modulated in the data modulation circuit 13, and the data modulation circuit 13 outputs the modulated data.

In step 263, a synchronization signal VFO for synchronization is added to the beginning of the data modulated by the VFO generation circuit 14.

In step 264, guard data for suppressing medium deterioration is added by the guard data generation circuit 200 to the first guard data record field and the second guard data record field following the user data at the head of the synchronization signal VFO.

In step 265, the recording intervals of the first and second gap fields are randomly determined by the amount of change of 0-15 channel bits, which is the resolution of one channel bit. Similarly, the amount of change in the recording section of the first and second guard data recording fields is randomly determined by the amount of change of 0 to 7 bytes, which is a resolution of 1 byte. In other words, by the extended portion of the first gap field, the length of the second gap field is shortened, and the total length does not change. Similarly, the total length of the first and second guard data record fields does not change.

In step 266, while randomly changing the recording intervals of the first and second gap fields and the first and second guard data recording fields, the recording signal is generated from the combined guard data, the synchronization signal VFO, and the modulated data.

In step 267, it is determined whether to change the polarity of the recording signal.

In step 268, if it is determined in step 267 to change the polarity, the polarity of the write signal is converted.

In step 269, the write signal determined in steps 263 to 268 is recorded in the corresponding sector recorded.

According to the above mechanism, signals are recorded on the optical disc in the format as shown in FIG.

Referring to FIGS. 14A to 14D, a random change state of the first and second gap fields and the first and second guard data fields will be described. 14A to 14D show the recording format of a sector by randomly changing the lengths of the first and second gap fields and the first and second guard data recording fields by the above method. The sector of the optical disk includes an address signal 401, a first gap field 402, a first guard data recording field 403, a recording signal 404 consisting of a synchronization signal VFO and user data, and a second guard data recording field ( 405, and a second gap field 406.

FIG. 14A shows a case where the change amount J of the first gap field 402 is at least J = 0 and the change amount K of the first guard data recording field 403 is at least K = 0. Therefore, the length of the first gap field 402 is the minimum value G1min and the length of the second gap field 406 is the maximum value G2max. The length of the first guard data recording field 403 is the minimum value D1min and the length of the second guard data recording field 405 is the maximum value D2max. In the case shown in Fig. 14A, the recording signal 404 is located at the most head position of the sector.

J = Jmax and K = 0 in FIG. 14 (b), J = 0 and K = Kmax in FIG. 14 (c), and J = Jmax and K = Kmax in FIG. 14 (d). Hereinafter, Jmax is the maximum change amount of the gap field, which is usually 15 channel bits, and Kmax is the maximum change amount of the guard field, which is usually 7 bytes. In the case shown in Fig. 14D, the recording signal 404 is located at the end of the sector. The length of the first gap field 402 is the maximum value G1max and the length of the second gap field 406 is the minimum value G2min. The length of the first guard data recording field 403 is the maximum value D1max and the length of the second guard data recording field 405 is the minimum value D2min.

15A to 15B are schematic diagrams of sector degradation. In Fig. 15 (a), J = 0 and K = 0, and in Fig. 15 (b), J = Jmax and K = Kmax. As shown in the figure, the deterioration 501 of the tip occurs in the first guard data recording field 403, and the deterioration area 504 of the tip is set to the total length Jmax of the maximum change amount of the first and second gap fields. Is formed. Similarly, the terminal degradation 502 occurs in the second guard data recording field 405, and the terminal degradation region 505 is formed with the total length Jmax of the maximum change amount portions of the first and second gap fields. However, this deterioration area prevents further expansion of the deterioration areas at the front end and the end in the first and second guard data recording fields, and the deterioration area has a detrimental effect on the recording signal 404 composed of the synchronization signal VFO and the user data. Does not have

In addition, in the recording signal 404 composed of the synchronization signal VFO and the user data, since the recording section changes randomly and extends to a resolution of 1 byte, the range 506 for inducing local oscillation is expanded. And local degradation 503 is dispersed, so local degradation can be reduced.

In an actual write operation, J is a channel bit, one byte consists of 16 channel bits, and K is a larger value than J. Thus, while the positions of the first and second gap fields randomly change every minute, the recording position varies more widely in the recording signal 404 surrounded by the first and second guard data recording fields.

In this embodiment, in order to satisfy the following requirement, J is set in channel bits and K is set in bytes. That is, the random shifts of the first and second gap fields are small in size so as not to extend the deterioration area at the recording start and end, while the random shift of the channel bits in the smallest unit for processing digital data is realized, while Deterioration is dispersed by increasing the amount of change in the recording field of the synchronization signal and the user data recording signal, and the information arrangement is simplified.

The first and second guard data recording fields prevent deterioration phenomena occurring at the leading and terminating ends due to repetitive recording from propagating to recording signals such as synchronization signal VFO and user data. Therefore, from the viewpoint of preventing the expansion of the deterioration area, the random shift will not be increased too much.

Local degradation in the recording signal, such as the synchronization signal VFO and the user data, will be preferably distributed by changing the byte area to extend the induction area, thereby reducing the possibility of the result due to the degradation.

Usually, when processing digital data, it is desirable to process the data in bytes. However, if the random shift is processed only in bytes, deterioration occurs in bytes, and deterioration in bytes easily occurs, so that the effect of preventing degradation of the medium is reduced as compared with random shifts in channel bits. On the other hand, if the random shift is always processed in units of channel bits where only a partial shift of 5 bits or 9 bits occurs, signal processing at the time of reproduction is difficult.

In this embodiment, according to this, since the random shift of the first and second gap fields in the period without a signal is in the unit of channel bits, deterioration in byte units can be prevented, and deterioration in byte units can be prevented. And deterioration at the beginning and end of the sector can be effectively suppressed. In the recording signal of the synchronization signal VFO and the user data, if the random shift is processed in units of bytes, the recorded area can be expanded so that degradation in units of marks can be dispersed, and reproduced data can be processed in units of bytes. Therefore, there is no inconvenience when processing signals during reproduction.

As a result, the recording position of the synchronizing signal VFO or the recording signal 404 of the user data as can be seen from all sectors is recorded in two stages of random shift (i.e., large random shift and small random shift) each time recording. Is changed over time. In this embodiment, for two types of degradation, namely, degradation and local degradation at the start and end of a sector occur per mark, and these degradations can be effectively reduced in recording and reproducing information.

Further, according to this embodiment, the polarity of the recording signal is randomly inverted every time recording. 16A to 16C show the relationship between the polarity of the recording signal and the actual recording state on the optical disk. The sector of the optical disc includes an address signal 604, a first gap field 606, a first guard data recording field 601, a recording signal 607 consisting of a synchronization signal VFO and user data, and a second guard data recording field ( 608 and second gap field 609 are formed.

If the polarity is not reversed, the recording signal 601 is recorded on the recording medium in state 602, and if the polarity is reversed, it is recorded on the recording medium in state 603. FIG. That is, by inverting the polarity, since the undissolved portion and the dissolved portion of the foil forming the mark are completely reversed, the effect of preventing deterioration can be obtained.

It is a figure which shows the result of having confirmed the result of the random shift of this invention by an Example. In this embodiment, the jitter value after repeatedly recording the same data signal in the sector of the optical disc is shown. After 100,000 recording iterations, a jitter value of 15% or less is regarded as a criterion for data reproduction, based on a guideline of less than one error rate per 10,000 times during demodulation.

In curve 50, the maximum change amount of the first gap field is Jmax = 15 channel bits, the maximum change amount of the first guard data recording field is Kmax = 7 bytes, and in curve 51, the maximum change amount of the first gap field. Is Jmax = 15 channel bits, the maximum change amount of the first guard data recording field is Kmax = 7 bytes, and polarity inversion is included.

As can be seen from curves 50 and 51, the desired conditions include the maximum amount of change in the first gap field of Jmax = 15 channel bits, the maximum amount of change in the first guard data record field of Kmax = 7 bytes, and the polarity conversion. Can be satisfied. From the viewpoint of the disk capacity, it is desired that the amount of change in the first gap field and the first guard data recording field is as small as possible, so that the maximum amount of change in the first gap field of Jmax = 15 channel bits, the first guard of Kmax = 7 bytes. It is determined that the combination of the maximum change amount of the data recording field and the polarity inversion are preferable.

In the stage of the present embodiment, the random shift is also Jmax = 15 channel bits and Kmax = 7 bytes, but later demodulates even after repeating 100,000 recordings with a small shift width in accordance with advances in technology such as the development of high performance recording thin film materials. We can get error rate less than once per 10,000 times. In this case, according to the present invention, as in the present embodiment, it is possible to suppress the deterioration phenomenon for recording accurate information and reproducing the information with a predetermined limited random shift amount.

Therefore, according to this embodiment, with the maximum amount of change of the first gap field of Jmax = 15 channel bits, the maximum amount of change of the first guard data recording field of Kmax = 7 bytes, the first gap field and the first guard each time a write is made. By randomly changing the length of the field and changing the polarity of the recording signal every time recording, the signal processing is easily performed with a limited amount of random shift, and in every sector and every mark when recording the information correctly and reproducing the information. Branches of deterioration can be suppressed.

In this embodiment, by setting the recording pattern of the guard data of the first guard data recording field to the same recording pattern of the synchronization signal field, and continuously keeping the phase of the recording signal between the first guard data recording field and the synchronization signal section In addition, the synchronization signal interval can be extended and system stability can be improved.

In addition, with the optical output in which at least one or more types are recorded in the optical disk apparatus using the reproduced optical output, the present invention can be clearly applied to not only the phase change optical disk but also the magneto-optical disk.

Claims (36)

In an optical disk having a plurality of sectors, Each of the sectors, A first gap field, which is a no-signal interval, a first guard data recording field for recording guard data, a data recording field containing a synchronization signal and subsequent user data, a second guard data recording field for recording guard data, and a no-signal interval Include the second gap field in order, The total length of the first and second gap fields and the total length of the first and second guard data record fields are constant, the length of the first and second gap fields and the first and second guard data records. The length of the field can be changed randomly every recording, and the amount of change of the first and second gap fields is smaller than the amount of change of the first and second guard data recording fields. delete delete delete delete delete delete delete delete delete delete delete An optical disk apparatus for operating an optical disk having a plurality of sectors divided from tracks, Guard data generating means for generating guard data in the first and second guard data recording fields; Synchronizing signal generating means for generating a synchronizing signal; (Iii) randomly vary the length of the first and second gap fields, which are no signal intervals, wherein the total length of the first and second gap fields is constant, at each recording time, and (ii) the first and second guards. The length of the data-the total length of the first and second guard data recording fields is constant-is randomly changed each time recording, and (i) the amount of change in the first and second gap fields is changed in the first and second guards. Random change means for controlling to be smaller than the change amount of the data recording field; (Iii) a first gap field, which is a no-signal interval, a first guard data recording field for recording guard data, a data recording field containing a synchronization signal and subsequent user data, a second guard data recording field for recording guard data, and Each sector including a second gap field which is a no-signal period in order, and (ii) based on the change amount of the first and second gap fields and the change amount of the first and second guard data recording fields, Recording control means for recording signals in the first and second guard data recording fields and in the data recording field; Optical disk device comprising a. delete delete delete delete delete delete delete delete delete delete delete An optical disc recording method having a plurality of sectors divided from tracks, the method comprising: A first gap field, which is a no-signal interval, a first guard data recording field for recording guard data, a data recording field containing a synchronization signal and subsequent user data, a second guard data recording field for recording guard data, and a no-signal interval Forming a sector structure including the second gap field in order; Setting the total length of the first and second gap fields and the first and second guard data recording fields to be constant, respectively; In recording, randomly changing the length of the first and second gap fields and the first and second guard data recording fields each time recording, and Controlling the amount of change in the first and second gap fields to be smaller than the amount of change in the first and second guard data recording fields. Optical disc recording method comprising a. delete delete delete delete delete delete delete delete delete delete delete