JP2000132838A - Recording and reproducing device of optical information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the number of repetitive recordings of a reloadable optical information recording medium. SOLUTION: An identifying means 119 identifies the recording condition at the reloading sectors on an optical disk 113. The range of the width of the change of a recording start point is set by a delaying amount control circuit 106 in accordance with the recording condition. The recording timing of modulation data signals 105 is varied within the range of the change width being set, and the reloading of the information of the sector on the disk 113 is conducted. Moreover, a dummy data generating means is provided to generate the dummy data to be added to modulation data signals and the length of the dummy data is varied in accordance with the change in the recording start point of the modulation data signals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium recording / reproducing apparatus for optically recording / reproducing information.

[0002]

2. Description of the Related Art In recent years, optical disks, optical cards, optical tapes and the like have been proposed and put into practical use as media for optically recording information. Among them, an optical disk has been particularly noted as a medium capable of high-capacity and high-density recording and reproduction.

[0003] A conventional recording / reproducing method for an optical disk will be described below with reference to the drawings. First, an example of a configuration of an optical disk using a phase change recording film as a recording film is shown in FIG.
3 is shown. A guide groove 2302 is formed in a substrate 2301 made of glass or a resin material (such as PMMA or polycarbonate).
Alternatively, uneven pits indicating address information and the like are formed in advance. Guide grooves are formed spirally from the inner circumference to the outer circumference,
ID areas indicating address information are arranged at predetermined intervals. I
The area of each guide groove between the D area and the ID area is called a sector. A protective film 2303, a recording film 2304, and a reflective film 2305 are deposited on the substrate 2301 by sputtering or the like, and a protective substrate 2306 is bonded.

The recording and reproduction of such an optical information recording medium will be described with reference to FIGS. FIG. 24 is a diagram showing a configuration example of a conventional recording / reproducing apparatus. FIG. 25
FIGS. 3A and 3B are diagrams for explaining the recording / reproducing operation of the optical disk, wherein FIG. 3A shows a recording data signal, FIG. 3B shows a laser driving signal, FIG. 3C shows a recording state on the optical disk, and FIG. Each is shown.

[0005] Reproduction from an optical disk is performed as follows.
The system control circuit 101 drives the spindle motor 114 to rotate the optical disk 113. Optical head 11
2 is a weak laser beam (laser power Pr in FIG. 25B).
And irradiates the optical disk 113 to track the guide groove 2302 and a series of pits 2502 in FIG. The amount of light reflected from the optical disk 113 changes depending on the presence or absence of the pits 2502 and the presence or absence of the recording marks 2501. The reflected light amount is detected and the RF signal 122 is detected.
Get. Then, the reproduced signal processing circuit 115 performs signal processing such as binarization and the like, and the demodulation circuit 116 demodulates the signal. Then, error correction is performed using the error correction information, and a deinterleaving process for restoring the rearranged recording information is performed to obtain desired reproduction information.

Next, recording on an optical disk is performed as follows. System control circuit 101 connected to host computer
Given the record information 102 which is binary information from
Error correction information (parity) is added to this record information,
Perform interleave processing. The interleave processing is for converting a burst error (continuous long error) due to a defect or the like of the optical disc 113 into a random error (short error) to facilitate error correction. Therefore, it is a process of dividing and rearranging. After that, in the modulation circuit 104, for example, (1,7) R
Modulation is performed by the LL modulation method. As a result, a modulated data signal 105 to be recorded in the data area 604 of FIG. 25D is obtained.

The synthesizing circuit 109 adds the VFO and RESYNC from the synchronizing signal generating circuit 108 and, if necessary, the dummy data from the dummy data generating circuit 107 for each data length to be recorded in each sector. 118. Both VFO and RESYNC are synchronization signals provided to generate a clock synchronized with the reproduction signal by a PLL (synchronous signal generator) in the reproduction signal processing circuit 115. VFO is arranged before the modulated data signal, and RESYNC is arranged at a fixed interval in the modulated data signal. Dummy data is provided to alleviate the influence of recording film deterioration occurring at the recording end point in a sector during repeated recording. Recording data signal 11
8 has a waveform as shown in FIG.

In response to the recording data signal 118, a laser drive signal 111 is generated by a laser drive circuit 110, and the laser in the optical head 112 is driven to modulate the intensity of the laser light. The laser drive signal 111 has a waveform as shown in FIG.

A strong laser beam (power Pp of the laser beam of FIG. 25B) focused by the optical head 112 of FIG. 24 is applied to the recording film of the optical disk 113 to raise the temperature of the recording film beyond the melting point. Then, the molten portion is rapidly cooled to become the recording mark 2501 in an amorphous state (FIG. 25C). When a laser beam (power Pb of the laser beam in FIG. 25B) is focused and irradiated to raise the temperature of the recording film to near the melting point, the recording film in the irradiated portion is heated to a temperature higher than the crystallization temperature. And slowly cooled to a crystalline state.

In this manner, a crystalline and amorphous recording pattern corresponding to the modulated data signal 105 is formed on the data area 604 of the guide groove 2302. Then, utilizing the difference in the reflectance between crystalline and amorphous, storage of information,
Playback is performed.

As shown in FIG. 25D, a gap region 6 is provided between the ID region 601 and the VFO region 603.
02, the dummy data area 605 and the next ID area 6
A buffer area 606 is provided between the data area 01 and the data area 01. The gap area 602 is an area for obtaining a time for controlling the laser power, and the buffer area 606 is an area for absorbing a deviation of a recording position due to uneven rotation of a spindle motor.

At the time of recording, a sector 607 of the optical disk is used.
When scanning the intervening ID area 601, the address information is reproduced by lowering the intensity of the laser beam to a weak power similar to that at the time of reproduction and irradiating the laser beam onto the optical disk.

By the way, if the recording on the optical disk is repeated as described above, the quality of the reproduction signal of the data recorded in the sector tends to locally deteriorate. In particular, when similar recording data is repeatedly recorded in the same sector, this tendency becomes remarkable. This is because, on the sector, a portion where melting / solidification is repeated many times and a portion where no melting occurs at all occur, and the thickness of the recording film fluctuates at the boundary between both portions, thereby deteriorating thermal and optical characteristics. . As a result, the quality of the data reproduction signal may be degraded or information may not be recorded.

In order to solve such a problem, there has been proposed a recording method for recording information by randomly shifting a data recording start point in a sector of an optical disc within a certain range (this is referred to as a change width). (See, for example, JP-A-2-94113).

[0015]

However, in the above-described conventional recording method, the change width of the recording start point is constant regardless of the recording medium and the recording conditions. On the other hand, the degree of deterioration of the recording film is determined not only by the number of repetitions of recording but also by the recording medium and recording conditions.

Therefore, in the conventional recording method, the deterioration of the recording film may not be sufficiently improved depending on conditions. For example, when rewriting a data area on an optical disc, rewriting is performed in sector units. Therefore, even if the information to be rewritten is a part of the sector, the entire sector is actually rewritten. In particular, in a TOC (Table of Contents) area (also referred to as a directory area) on the disc, information corresponding to a table of contents of information recorded on the disc is recorded, so that the frequency of repeated recording is high and very similar. The data is rewritten. Therefore, in this area, the recording film tends to deteriorate earlier than in an area in which actual information is recorded (this is called a general area).

If the change width of the recording start point is increased, the deterioration of the recording film is improved. However, since the data area must be accommodated in the sector, the area usable for VFO and dummy data in the sector decreases. Will be. That is,
When a VFO for obtaining a synchronization signal is added before the data area and dummy data for addressing the recording film deterioration occurring at the end of the sector is added after the data area, the change width of the data recording start point is changed. If it is increased, the length of the VFO portion and the dummy data portion must be shortened. For this reason, the recording film becomes sensitive to deterioration of the recording film at the start and end portions of the sector which occurs when repeated recording is performed.
That is, there is a high possibility that information cannot be reproduced with respect to the same deterioration of the recording film. As a result, the number of times of repetitive recording is reduced.

According to the present invention, in order to solve the above-mentioned conventional problems, the deterioration of the recording film of the optical disk can be appropriately suppressed by changing the change width of the recording start point of the data area in accordance with the recording conditions. It is another object of the present invention to provide a recording / reproducing apparatus capable of further increasing the number of times of repetitive recording.

[0019]

In order to achieve the above object, a recording / reproducing apparatus for an optical information recording medium according to the present invention comprises a recording / reproducing apparatus for a rewritable optical information recording medium having a sector structure format. A modulation unit that converts an information signal into a modulation data signal corresponding to a recording pattern on a recording medium, and a recording start point of the modulation data signal given from the modulation unit, within a range of a predetermined change width. Recording control including first delay means for changing, and second delay means for changing the recording start point of the modulated data signal provided from the modulator within a range of a change width larger than the predetermined change width. And a selector for selecting one of the first delay means and the second delay means when recording information on a recording medium, and generating dummy data to be added to the modulated data signal. With Mie data generating means and varying the length of the dummy data in accordance with a change of the recording start point of the modulated data signal.

In this manner, the width of change of the recording start point can be set according to the recording medium and recording conditions. Therefore, in the case of a recording method or a medium in which the recording film deterioration is remarkable, by increasing the change width, it is possible to improve the local deterioration of the recording film at the time of repetitive recording and increase the number of times of repetitive recording. On the other hand, in a recording method and a medium in which the recording film is less deteriorated with respect to the repetitive recording, the length of the VFO and the dummy data can be increased to cope with the deterioration at the start and end of the sector, and the number of repetitive recordings can be increased. The recording conditions and information on the recording medium can be recorded on the medium as identifiers. Alternatively, the variation width may be changed according to the type of the modulated data signal. Further, recording conditions such as the repetitive recording frequency of the sector to be recorded, whether or not the sector to be recorded is in the TOC area, whether the sector is on a groove (guide groove) or on a land (between the guide grooves). It is preferable to set the change width of the recording start point according to the following.

In the above method, it is preferable that the selector selects the function of the first delay unit or the function of the second delay unit according to the type of the modulated data signal.

In the above method, there is provided a detection unit for detecting whether or not the area is a region where the repetitive recording frequency is high, and when the repetition recording frequency is high, the selecting unit selects the second delay means, and When the first delay unit is low, the selection unit preferably selects the first delay unit.

In the above method, when the sector to be recorded is in the TOC area, the selector selects the second delay means. When the sector to be recorded is an area other than the TOC area, the selector selects the second delay means. Preferably, the first delay means is selected.

Further, in the above method, a detecting unit for detecting whether a sector to be recorded is on a groove or a land is included, and the selecting unit is configured to detect the first delay unit based on a detection result of the detecting unit. Alternatively, it is preferable to select the second delay means.

In the above method, when the modulator obtains the modulated data signal by pulse width modulation, the selector selects the second delay means and obtains the modulated data signal by pulse position modulation. It is preferable that the selector selects the first delay unit.

In the above method, the first delay means and the second delay means change the delay time stepwise,
It is preferable that the number of steps of change of the delay time by the second delay means is larger than the number of steps of change of the delay time by the first delay means.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of a recording / reproducing apparatus for a scientific information recording medium according to the present invention will be specifically described with reference to the drawings.

(Embodiment 1) FIG. 1 is a diagram showing a configuration of a recording / reproducing apparatus according to the present invention, and FIG. 2 is a flowchart for explaining an operation of rewriting recording information of a certain sector in Embodiment 1 of the present invention. is there. The system control circuit 101 connected to the host computer detects the address information of the sector to be rewritten on the optical disk 113 (step 20).
After 1), the system control circuit 101 outputs the record information 102 which is binary information (step 202).

Then, error correction information is added to the recording information and interleaving is performed (step 203), and modulation is performed by the modulation circuit 104 (step 204). The above operation is the same as the configuration of the conventional example.

Next, the modulation data signal 105 output from the modulation circuit is input to the delay amount control circuit 106. The delay amount control circuit 106 reduces the change width of the recording start point in the general area (step 207) according to the identification result of whether or not the corresponding area is a high repetition recording frequency area such as the TOC area (step 205). In the TOC area, the change width of the recording start point is set large (step 206). The above-described identification result is obtained by detecting the identifier by the identification means 119. The identifier is the ID of each sector in advance.
It is recorded in an area (601 in FIG. 25) and the like.

The delay amount control circuit 106 randomly delays the modulated data 105 within a range of a delay amount corresponding to the set change width (step 208). Details of the configuration of the delay amount control circuit will be described later.

Then, the synthesizing circuit 109 adds a synchronizing signal (VFO) from the synchronizing signal generating circuit 108, dummy data from the dummy data generating circuit 107, etc. for each data length to be recorded in each sector, and (Step 209). The recording data signal 118 is input to the laser drive circuit 110, and the laser drive signal 111
Is generated, and the laser in the optical head 112 is driven. Then, the intensity of the laser beam is modulated (step 21).
0), irradiate the optical disk 113 and record it in the corresponding sector (step 211).

Next, the delay amount control circuit 106 will be described. FIG. 3 shows an example of the configuration of the delay amount control circuit 106. The delay amount control circuit includes a recording control unit having two different types of recording timing setting functions, and a selecting unit for selecting the recording timing setting function according to an identifier. FIG.
In the delay amount control circuit of FIG. The recording control unit includes a plurality of delay circuits 301 and 30
The circuit comprises two clock generating circuits 302 and 303 for generating a clock for operating the clock signal 1, and a selector 304 for determining an input destination of the modulated data signal 105 to the delay circuit 301.

The delay amount of the delay circuit 301 is 0, T, 2T, 3T,..., 1 according to the delay clock T.
It is set to be 6T. That is, when the clock is T, the interval between the stages in which the delay amount changes is T, and the number of stages of the delay amount is 16. Each delay circuit is constituted by a shift register, a delay line, a counter and the like.

In the delay amount control circuit of FIG. 3, two clock generation circuits 302 and 303 are provided. By switching the selection circuit 305, the first clock generation circuit 302
Is selected, the delay circuit 301 randomly changes the recording timing within a range of change from 0 to 16T (first recording timing setting function). Also, the selection circuit 305
When the second clock generation circuit 303 is selected, the delay circuit 301 randomly changes the recording timing within the range of change from 0 to 160T (second recording timing setting function).

The actual operation of the delay amount control circuit of FIG. 3 is as follows. When recording in the general area of the optical disk 113, the selection circuit 305 is switched to the first clock generation circuit 302 in accordance with the signal 121 from the identification means 119. The first clock generation circuit 302 outputs the clock T and generates a delay amount from 0 to 16T. Then, the destination of the selector 304 is randomly determined by the address detection signal 120 from the system control circuit. The destination of the selector is held until the next address is detected.

On the other hand, when recording in the TOC area, the selection circuit 3
05 is switched to the second clock generation circuit 303. The second clock generation circuit 303 outputs the clock 10T and generates a delay amount from 0 to 160T. Then, the destination of the selector 304 is randomly determined by the address detection signal 120 from the system control circuit. In this way, by changing the interval of each stage of delay between the TOC area and the other area, the change width of the recording start point of the data area can be made different.

FIG. 4 is a diagram showing another example of the configuration of the delay amount control circuit. In the delay amount control circuit of FIG. 4, the selection unit includes a selection circuit 405. The recording control unit includes a plurality of delay circuits 40
1, a clock generation circuit 402 for generating a clock for operating the delay circuit 401, and two selectors 403 and 404 for determining an input destination of the modulated data signal 105 to the delay circuit 401.

The delay amount of the delay circuit 401 is set to be 0, T, 2T, 3T,..., 160T according to the delay clock T. That is, the interval between the stages in which the amount of delay changes is T, and the width of change in the amount of delay is 160T.
It is.

The delay amount control circuit of FIG. 4 has two selectors 403 and 404. When the selection circuit 405 is switched to select the first selector 403, the delay circuit 40
Numeral 1 randomly changes the recording timing within a range of change from 0 to 16T (first recording timing setting function). Further, the selection circuit 405 controls the second selector 40.
When 4 is selected, the delay circuit 401 randomly changes the recording timing within the range of change from 0 to 160T (second recording timing setting function).

The actual operation of the delay amount control circuit of FIG. 4 is as follows. When recording in the general area of the optical disk 113, the selector 405 is switched so as to pass through the first selection circuit 403 according to the signal 121 from the identification means 119, and any one of the 16-stage delay amounts of the delay circuits 1 to 16 is determined. And a delay amount of 0 to 16T is generated. Then, the first selection circuit 403 is operated by the address detection signal 120 from the system control circuit.
Is randomly determined. The destination of the selector is held until the next address is detected.

On the other hand, when recording in the TOC area, the selector 4
05 is switched so as to pass through the second selection circuit 404, and any one of the 160-stage delay amounts of the delay circuits 0 to 160 is selected to generate a delay amount of 0 to 160T. Then, the destination of the second selection circuit 404 is randomly determined based on the address detection signal 120 from the system control circuit. In this way, by changing the number of delay stages between the TOC area and the other area, the width of change of the recording start point of the data area can be made different.

Next, a comparative experiment (example) performed to confirm the effect of the present embodiment will be described. For the disk substrate of the optical disk 113, a polycarbonate resin having a diameter of 130 mm and a thickness of 0.6 mm was used. On this resin substrate, irregular phase pits were preformatted in advance as address information, and recording guide grooves were formed in the sector areas. The pitch of the guide grooves is 1.6 μm. On the substrate, a protective film, a photosensitive recording film, a protective film, and a reflective film were formed in four layers by a sputtering method, and the protective substrate was bonded thereon.

ZnS-SiO ₂ was used as a protective film, Te-Sb-Ge as a photosensitive recording film, and Al as a reflective film. Then, the disk was rotated by a spindle motor 113 at a linear velocity of 5 m / s, and laser light having a wavelength of 680 nm was focused by an objective lens having a numerical aperture (NA) of 0.6 to perform recording.

The power of the laser beam at the time of recording / reproduction is Pp = 1
0 mW, Pb = 4 mW, and Pr = 1 mW. As the modulation method of the recording information, (1,7) RLL pulse width modulation was used. The shortest mark length was 0.6 μm. As shown in FIG. 3, the delay amount control circuit 109 employs a configuration in which the clock generation circuits 302 and 303 set the intervals of each stage to determine the change width of the recording start point.

Using the above conditions, first, the relationship between the change width of the recording start position in each area and the error rate of the reproduced information was examined. In the TOC area, two patterns of recording information are repeatedly recorded on the assumption that similar recording information is recorded, and the variation width is 0 to 160T (interval of each step is 0 to 10T).
T). In the general area, recording information of 30 patterns was repeatedly recorded, and the variation width was set in a range of 0 to 64T (interval of each step was 0 to 4T). Then, the error rate of the reproduced information after the recording was repeated 10,000 times was measured.

FIG. 5A is a graph plotting the relationship between the change width of the recording start position in the general area and the error rate of the reproduced information after 100,000 times of repeated recording. FIG. 5B plots the relationship between the change width of the recording start position in the TOC area and the error rate of the reproduced information after 100,000 times of repeated recording.

FIG. 5 shows that the larger the change width of the recording start position, the better the error rate can be obtained after 100,000 times of repeated recording. Then, it was found that the minimum change width at which a good error rate was obtained was different in each area (that is, the randomness of recorded information).

From the above results, the change width of the recording start point was set as follows. As a variation width at which an error rate of 5 × 10 ⁻⁴ or less can be obtained, the variation width in the general area is 16T, the interval between each step is 1T, and the variation width in the TOC area is 160.
T, the one in which the interval of each step is 10T is a variable width variable system. As a comparative example, the change width in both regions is 16T, and the interval between each step is 1T, and the change width fixed method 1 is used. The change width in both regions is 160T, and the interval between each stage is 10T. This was designated as fixed change width method 2.

Next, the recording format set for each of the above methods will be described below. FIG. 6 is a diagram showing a recording format when the change width of the recording start point is set to 16T. Here, the data recording clock is the same as the delay clock T, the data capacity that can be recorded in one sector is 1000 bytes, and the length of the VFO and dummy data when the recording start point is not changed is 15 bytes. .

FIG. 6A shows a recording format when the recording start point is not changed. Data area 604
The VFO 603 and the dummy data 605 are added after the delay is added by the delay amount control circuit 109 in FIG. 1, and these are input to the laser drive circuit 110 to generate the laser drive signal 111.

FIG. 6B shows a recording format when the recording start point is shifted backward by 16T (1 byte). In this case, the laser drive signal (111 in FIG. 1) is
It occurs at a time later by 16T than in the case of FIG. When recording with a change width of 16T, the timing at which the laser drive signal is generated by the delay amount control circuit changes within the range of 16T, and as a result, the recording position of the data area in the sector is within the range of 16T (1 byte). Change.

FIG. 7 is a diagram showing a recording format when the change width of the recording start point is set to 160T. FIG. 7A shows a recording format when the recording start point is not changed. FIG. 7B shows that the recording start point is 80T.
This is the format of the recording when shifting forward by (5 bytes). In the case of FIG. 7B, the laser drive signal (111 in FIG. 1) is generated at a time earlier by 80T than in the case of FIG. 7A. FIG. 7C shows that the recording start point is 80T.
This is the recording format when shifting backward by (5 bytes). In the case of FIG. 7C, the laser drive signal (111 in FIG. 1) is generated at a time later by 80T than in the case of FIG. 7A.

When recording with a change width of 160T, the timing at which the laser drive signal is generated by the delay amount control circuit changes within the range of 160T, and as a result, the recording position in the sector is within the range of 160T (10 bytes). Change. The length of the sector is determined in advance by the ID pit / ID mark formed on the optical disk. Therefore, the gap region 802 and the buffer region 80
In the case where the length is fixed, the length of the VFO and the dummy data decreases as the change range of the recording position in the sector increases.

In the fixed change width method 1, the change width is 1 byte regardless of whether it is in the TOC area or not.
As shown in (b) and (b), the lengths of the VFO and the dummy data vary within a range of 15 to 16 bytes (or 14 to 15 bytes), respectively, and the VFO and the dummy data have a minimum length of 14 (or 15) bytes. is there. Also,
In the fixed change width method 2, the change width is 10 bytes irrespective of whether the area is the TOC area or not. Therefore, as shown in FIGS. And the VFO and dummy data are 10 bytes in the shortest case.

On the other hand, in the variable change width method, since the change width of the recording start point is 10 bytes in the case of the TOC area, the lengths of the VFO and the dummy data are as shown in FIGS. Each range from 10 to 20 bytes,
The shortest VFO and dummy data are 10 bytes. Further, in the case of the general area, the change width of the recording start point is 1 byte. Therefore, as shown in FIGS. 6A and 6B, the length of the VFO and the dummy data when the recording start point is changed Are 15-16 (or 14-1
5) It fluctuates in the range of bytes, and the VFO and the dummy data are 14 (or 15) bytes in the shortest case.

Using the above conditions, two patterns of recording information in the TOC area and 30 patterns of recording information in the general area are repeatedly rewritten and recorded in the same sector, and the error occurrence state after 50,000 and 100,000 repetitions. Was examined.

Table 1 shows a comparison between the variable change width method, the fixed change width method 1, and the fixed change width method 2. here,
"Synchronization error" indicates a state in which information cannot be reproduced because the PLL is no longer locked, and "reproduction error" indicates a state in which information cannot be reproduced because complete error correction becomes impossible. Represents.

[0059]

[Table 1]

As shown in Table 1, in the fixed change width method 1, the sector in the general area could be reproduced even with 100,000 repetitions. However, an error occurred 50,000 times in the TOC area. In the case of the sector in the TOC area, the envelope of the reproduced waveform was distorted at this point. From this, it is considered that in the first conventional example, an error occurred due to local deterioration of the recording film because the change width of the recording start point was too small with respect to recording with low randomness.

In the fixed change width method 2, reproduction was possible in any area when the number of repetitions was 50,000 times.
Every time, an error occurred. In any area, the reproduced waveform after 100,000 repetitive recordings is VFO
At least 5 bytes have disappeared. For this reason, in the second conventional example, the change amount of the recording start point is large and the VF
Since the length of O may be shortened, the ratio of the degraded area in the VFO area becomes relatively large due to the deterioration of the recording film at the beginning of the sector, and it is considered that the PLL is no longer locked and an error has occurred.

On the other hand, in the variable change width system, reproduction can be performed in any area when the number of repetitions is 50,000 times.
Even in the general area, reproduction was possible even for 10,000 times. This is thought to be because when recording in the general area, the amount of change in the recording start point was reduced and the length of the VFO area was set longer, so that the ratio of the deteriorated area in the VFO area became relatively smaller. Can be In the TOC area, since the change width of the recording start point is increased, the local recording film deterioration in the data area does not significantly occur, and it is considered that reproduction was possible up to 50,000 times.

As described above, according to the recording / reproducing method for the optical information recording medium according to the present embodiment, the change width of the recording start point can be set in accordance with the recording conditions. In the case of a remarkable TOC area, by increasing the change width, it is possible to improve the local deterioration of the recording film at the time of repetitive recording and increase the number of times of repetitive recording. Further, in a general area where the recording film is less deteriorated with respect to the repetitive recording, the length of the VFO and the dummy data can be increased to deal with the deterioration of the start and end of the sector, and the number of repetitive recordings can be increased.

In the embodiment shown in FIG. 1, the delay amount control circuit 106 is provided before the synthesizing circuit 109.
As shown in FIG.
6 may be provided. In the configuration of FIG. 8, a flowchart showing the operation of rewriting a certain sector is as shown in FIG.
FO 603 and dummy data 605 are added (13
It is different from the flowchart of FIG. 2 in that the recording data signal is delayed by the delay amount control circuit 106 from step 08) (1309).

FIG. 10 shows a recording format when the change width is 16T. FIG. 10A shows a recording format when the recording start point is not changed, and FIG. 10B shows a recording format when the recording start point is delayed by 16T.

The recording format when the change width is 160T is as shown in FIG. FIG. 11A shows a case where the recording start point is not changed, FIG. 11B shows a case where the recording start point is advanced by 80T, and FIG.
This is the format of the record when delayed.

In these cases, the recording start points of the VFO 603, the data area 604, and the dummy data 605 are all changed, which is different from FIGS. As a result, VF
Since the lengths of O and the dummy data are not reduced, there is an advantage that the influence of deterioration of the start and end of the sector is less likely.

When the rotation jitter of the spindle motor 114 is small, or when the laser power control operation of the laser drive circuit 110 is sufficiently fast, the configuration shown in FIG. 8 is more preferable. Conversely, when the rotation jitter 114 of the spindle motor 114 is large, or when the laser power control operation of the laser drive circuit 110 is not fast, the configuration shown in FIG. It is more preferable to secure the constant gap area 602 and the buffer area 606 regardless of the change of the data.

As another method of recording information at high density, a method of recording information on a land between a guide groove (groove) has been proposed. In this case, since the groove and the land have different cross-sectional shapes of the substrate around the recording mark, the thermal burden on the recording mark peripheral portion is different. Therefore, even if recording is repeated the same number of times, a phenomenon occurs in which the degree of deterioration of the recording film differs between the groove and the land.

In order to solve such a problem, the recording / reproducing apparatus may be configured as shown in FIG. FIG. 12 differs from FIG. 1 in that the change amount of the recording start point is set by the delay amount control circuit based on the identification result of the land / groove identification means 1201. In this case, the width of change is different between when recording on a land and when recording on a groove.
Then, an effect similar to that of the configuration in FIG.

Further, in order to record information at high density, it has been proposed to use pulse width modulation (Pulse Width Modulation) in which information is provided at both edges of a recording mark. However, in pulse width modulation, pulse position modulation (Pulse Position Modulation) that gives information to the position (interval) of a recording mark.
(Modulation), a recording mark is often formed longer, so that the recording film tends to deteriorate faster. further,
In pulse width modulation, information cannot be reproduced unless the edge of the recording mark can be accurately detected, so that the information reproducing capability becomes more sensitive to deterioration of the recording film. That is, even if the recording film is deteriorated to the same extent, it is difficult to accurately reproduce information by pulse width modulation.

In order to solve such a problem, the recording / reproducing apparatus may be configured as shown in FIG. FIG. 13 differs from FIG. 1 in that the change width of the recording start point is set by the delay amount control circuit 106 based on the identification result of the modulation scheme identification means 1301. In this case, when recording with pulse width modulation,
The change width of the recording start point differs between when recording by pulse position modulation. Then, an effect similar to that of the configuration in FIG.

The change width of the recording start point, the number of steps, the interval, the recording format, and the like are not limited to those described in the present embodiment, but appropriate values can be set according to the recording conditions and the medium. It is possible. Further, it is needless to say that the change width of the recording start point may be changed to three or more types by combining the modulation method, the frequency of repeated recording, the land / groove, and the like as needed.

(Embodiment 2) Next, a recording / reproducing method for an optical information recording medium according to another embodiment of the present invention will be described. FIG. 14 is a diagram showing a configuration of a recording / reproducing apparatus according to the present embodiment, and FIG. 15 is a flowchart for explaining an operation of rewriting recording information of a certain sector in the present embodiment.

14 and 15 are different from the conventional configuration / operation in that the reordering method determining means 1401 prior to adding the error correction information uses the reordering method (conversion) of the recording information emitted as the information signal 102. Pattern) is randomly determined (step 1503), and the sorting means 1
At 402, a series of recording information is divided and rearranged (converted) to obtain a recording signal 1405 (step 15).
04), rearrangement information for restoring the rearranged recording information is newly added as an identification signal (step 150).
5) It is a point.

FIG. 16 is a flowchart for explaining the operation of reproducing the recorded information recorded in a certain sector in the present embodiment. 14 and FIG. 16 is different from the conventional configuration / operation in that after performing error correction and deinterleaving (step 1604), information for restoring recorded information is detected as an identification signal by the reordering information detecting means 1403. (Step 1605), and the restoring unit 1404 uses the restoration pattern determined based on the detection result.
The point is that the recorded information is restored (step 1606).

Sorting means 1402 and restoring means 14
Numeral 04 designates division and rearrangement of recording information in the following manner by using a buffer memory together. FIG.
FIGS. 7 and 18 are diagrams showing an example of a state of rearrangement of recording information.

For a series of recording information as shown in FIG. 17 (a), the division position is determined at random. Then, the recording information is divided, replaced, and rearrangement information indicating the divided position is added after the recording information to obtain the state shown in FIG. 17B. For example, when the recording information is divided at the 20th byte, information indicating the “20th byte” is added to the recording information. Note that the rearrangement information does not necessarily need to be recorded in each sector, but may be recorded in the TOC area (directory area). The reordering method for one rewrite need not always be different for each sector, and the reordering method may be the same for a series of rewrites for a plurality of sectors. Then, error correction information addition and interleave processing are performed.

At the time of reproduction, as shown in FIG. 18A, after performing error correction and deinterleave processing, rearrangement information added to the end of recorded information is detected. For example, if the rearrangement information is information indicating the "20th byte", the rear 20 bytes of the recording information excluding the rearrangement information of the recording information are divided and added to the head, thereby obtaining the information shown in FIG. Thus, the original record information is obtained as shown in FIG.

Since the reordering unit 1402 shown in FIG. 14 randomly determines the number of bytes at which the division is made in each sector, even if the same record information is repeatedly recorded in the same sector, it always differs. Recording is performed using the modulated data signal. as a result,
The recording data signals other than the VFO area and the RESYNC area are always recorded on the optical disc 113 by using different recording data signals. The probability that the recording mark 2501 is formed in the guide groove 2302 of the optical disc 113 depends on any position of the recording area in the sector. Are also approximately equal. Therefore, local damage that has occurred in the recording area due to rewriting many times is eliminated.

The effects of this embodiment will be described below with reference to specific examples. The conditions for recording on the optical disk were the same as in the previous embodiment. For the disk substrate of the optical disk 113, a polycarbonate resin having a diameter of 130 mm was used.
On this resin substrate, irregular phase pits were preformatted in advance as address information, and recording guide grooves were formed in the sector areas. A protective film, a photosensitive recording film, a protective film, and a reflective film are formed on a substrate by sputtering.
A layer was formed, and a protective substrate was adhered thereon.

In this embodiment, ZnS—SiO ₂ is used as the protective film.
Te-Sb-Ge as a photosensitive recording film, Al as a reflective film
Was used. Then, the disk is rotated at a linear velocity of 5 m / s by the spindle motor 113, and the wavelength is 680 nm.
The laser beam of m was focused by an objective lens having a numerical aperture (NA) of 0.6 and recording was performed. The power of the laser beam during recording and reproduction was set to Pp = 10 mW, Pb = 4 mW, and Pr = 1 mW.
The modulation method of the recording information used was (1,7) RLL pulse width modulation. The shortest mark length is 0.6 μm.

Using the above conditions, the same recording information was repeatedly recorded in the same sector 100,000 times. Then, a comparison was made between the recorded information rearrangement method in which the recording information was divided into two at random positions and rearranged for each repetitive recording, and the measured error rate of the reproduced signal in the conventional system without rearrangement. In either method, the recording information to be recorded in one sector is 500 bytes, and in the recording information rearranging method,
The division position was randomly determined in byte units. Table 2 shows the comparison results.

[0084]

[Table 2]

As is clear from Table 2, the recording information rearranging method has an excellent effect in that the error rate after 100,000 repetitive recordings is low and the number of repetitive recordings can be increased. .

As described above, according to the recording / reproducing method for the optical information recording medium according to the present embodiment, even when the same record information is repeatedly rewritten at the same position on the disc, conversion to a plurality of different patterns is performed. Since the recording data signal has a different pattern, damage to a specific position of the recording film is dispersed, and deterioration of the recording film due to rewriting many times can be suppressed.

Note that the number of divisions of the recording information and the like are not limited to those shown in the present embodiment, and appropriate values can be set according to recording conditions and media.

The method of converting a series of recording information is not limited to the method described in the present embodiment, and any method may be used as long as it converts the same recording information into any of two or more different patterns. Such a thing may be used.

For example, as shown in FIG. 19, a plurality of interleaving systems may be provided in an interleaving circuit. In this configuration, at the time of recording, one of the interleave methods (103, 1903) is set to the first selection circuit 1
It differs from FIG. 14 in that interleaving processing is performed by selecting randomly at 902 and information indicating the interleaving method is added to the recording information. At the time of reproduction, one of the deinterleaving methods (117, 1904) is selected by the second selecting circuit 19 based on the information indicating the interleaving method detected by the interleaving method detecting means 1906.
The difference from FIG. 14 is that the deinterleaving process is performed by selecting at random 05.

FIG. 20A shows an example of the state of the recorded information before performing the interleave processing. FIG. 20 (b)
Indicates a state in which information indicating an interleaving method is added after the interleaving process. FIG. 20C shows an example of the state of the recording information before the deinterleave processing is performed. FIG. 20D shows a state after deinterleaving processing is performed based on information indicating the interleaving method. In this case, the division and rearrangement processing of the recorded information can be used also as the interleave processing, so that the configuration of the recording / reproducing apparatus can be simplified.

The following method may be used to convert the same recording information into two or more different patterns.

FIG. 21 shows a configuration in which a bit shift is performed for each recording information unit. In this configuration, at the time of recording, the number of bits to be shifted is randomly determined by the bit shift method determining means 2101, and the bit shift circuit 2102 sets a fixed number of bits for each specific recording information unit (for example, one byte of recording information). After performing the shift process, the recording signal 1
405 is obtained, and information indicating the bit shift amount of each recording information unit is added as an identification signal, which is different from FIG. 14 is different from FIG. 14 in that at the time of reproduction, an inverse bit shift process is performed by an inverse bit shift circuit 2104 based on information indicating the number of bit shifts detected by the bit shift information detection means 2103.

FIG. 22A shows an example of the state of the recorded information before the bit shift processing. FIG. 22B shows a state in which information indicating the bit shift method is added after the bit shift processing. FIG. 22C shows an example of the state of the recorded information before the reverse bit shift process is performed. FIG. 22D shows a state after the inverse bit shift processing is performed based on the information indicating the bit shift method. In this case, it is not necessary to secure many buffer memories for the rearrangement, and the configuration of the recording / reproducing apparatus can be simplified.

Further, if the recording is started while the recording start point of the data area in the sector is changed at random, the RESYNC area in the data area is also recorded at a different position, so that the number of times of repetitive recording is further increased. be able to.

[0095]

As described above, according to the recording / reproducing apparatus of the present invention, information is recorded by randomly changing the recording start point of the data in the sector of the optical information recording medium, and the recording start point is recorded. In the case of a medium or a recording method in which the recording film is remarkably degraded, the variation width is increased at the expense of the length of the VFO or dummy data, and the recording width during repetitive recording is increased. By improving the local deterioration of the film, the number of times of repetitive recording can be increased. On the other hand, a medium or a recording method in which the recording film has little deterioration with respect to the repetitive recording can cope with the deterioration of the start and end of the sector by increasing the length of the VFO and the dummy data, and can increase the number of repetitive recordings.

[Brief description of the drawings]

FIG. 1 is an exemplary view for explaining the configuration of a recording / reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating an operation of rewriting recording information of a certain sector in the recording / reproducing apparatus of FIG.

FIG. 3 is a diagram illustrating a configuration of a delay amount control circuit in the recording / reproducing apparatus of FIG. 1;

FIG. 4 is a view for explaining another configuration of the delay amount control circuit in the recording / reproducing apparatus of FIG. 1;

FIG. 5A is a diagram illustrating a relationship between a change width of a recording start point and an error rate in a general area. FIG. 3B is a diagram illustrating a relationship between a change width of a recording start point and an error rate in a TOC area.

FIG. 6 is a diagram showing a recording format when a change width is 16T in the recording / reproducing apparatus of FIG. 1;

FIG. 7 is a diagram showing a recording format when the change width is 160T in the recording and reproducing apparatus in FIG. 1;

FIG. 8 is a diagram showing a modification of the recording / reproducing device of FIG. 1;

9 is a flowchart showing an operation of rewriting recording information of a certain sector in the recording / reproducing apparatus of FIG.

FIG. 10 is a diagram showing a recording format when the change width is 16T in the recording and reproducing apparatus in FIG. 8;

11 shows a change width of 160T in the recording / reproducing apparatus of FIG.
The figure which shows the format of the recording at the time of.

FIG. 12 is a diagram showing another modified example of the recording and reproducing device of FIG. 1;

FIG. 13 is a diagram showing another modified example of the recording / reproducing device of FIG. 1;

FIG. 14 is a diagram showing a configuration of a recording / reproducing device according to a second embodiment of the present invention.

FIG. 15 is a flowchart showing an operation of rewriting recording information of a certain sector in the recording / reproducing apparatus of FIG. 14;

FIG. 16 is a flowchart showing an operation of reproducing recording information of a certain sector in the recording / reproducing apparatus of FIG. 14;

17A is a diagram showing a state before rearrangement of recording information in the recording / reproducing apparatus of FIG. 14; FIG. 15B is a diagram showing a state after the recording information is rearranged in the recording / reproducing apparatus of FIG. 14.

FIG. 18A is a diagram showing a state before restoring recorded information in the recording / reproducing apparatus of FIG. 14; FIG. 15B is a diagram showing a state after restoring recorded information in the recording / reproducing apparatus of FIG. 14.

FIG. 19 is a diagram showing a modification of the recording / reproducing apparatus of FIG.

20A is a diagram showing a state before rearranging recording information in the recording / reproducing apparatus of FIG. 19; FIG. 20B is a diagram showing a state after the recording information is rearranged in the recording and reproducing apparatus of FIG. FIG. 20C is a diagram showing a state before restoring recorded information in the recording / reproducing apparatus of FIG. FIG. 20D is a diagram illustrating a state after the recording information is restored in the recording / reproducing apparatus in FIG. 19.

FIG. 21 is a diagram showing another modified example of the recording / reproducing device of FIG. 14;

FIG. 22A is a diagram showing a state before recording information is converted in the recording / reproducing apparatus of FIG. 21; FIG. 22B is a diagram showing a state after recording information has been converted in the recording / reproducing apparatus of FIG. 21; FIG. 22C is a diagram showing a state before restoring recorded information in the recording and reproducing apparatus of FIG. 21. FIG. 22D is a diagram illustrating a state after recording information is restored in the recording and reproducing apparatus in FIG. 21.

FIG. 23 is a diagram showing an example of a cross section of a conventional optical information recording medium.

FIG. 24 is a diagram showing a configuration of a conventional recording / reproducing apparatus.

FIG. 25A is a diagram showing a state of a recording data signal in a conventional recording / reproducing method. (B) is a diagram showing a state of intensity modulation of laser light in a conventional recording / reproducing method. (C) is a diagram showing a recording state on an optical disc in a conventional recording / reproducing method. (D) is a diagram showing a recording format in a conventional recording and reproducing method.

[Explanation of symbols]

 Reference Signs List 101 system control circuit 102 information signal 103 error correction / interleave circuit 104 modulation circuit 105 modulated data signal 106 delay amount control circuit 107 dummy data generation circuit 108 synchronization signal generation circuit 109 synthesis circuit 110 laser drive circuit 111 laser drive signal 112 optical head 113 Optical disc 114 Spindle motor 115 Reproduction signal processing circuit 116 Demodulation circuit 117 Error correction / deinterleave circuit 118 Recording data signal 119 Recording frequency identification means 120 ID detection signal 121 Recording frequency identification signal 122 RF signal 301 Delay circuit 302 First clock generation circuit 303 second clock generation circuit 304 selector 305 selection circuit 306 recording control unit 307 selection unit 401 delay circuit 402 clock generation circuit 403 Selector 404 second selector 405 selection circuit 406 recording control unit 407 selection unit 601 ID area 602 gap area 603 VFO area 604 data area 605 dummy data area 606 buffer area 607 sector 1401 sorting information determining means 1402 sorting means 1403 Replacement information detecting means 1404 restoring means 1405 recording signal

Claims (1)

[Claims] 1. A recording / reproducing apparatus for a rewritable optical information recording medium having a sector-structure format, comprising: a modulation unit for converting an information signal into a modulation data signal corresponding to a recording pattern on the recording medium; A first delay means for changing the recording start point of the modulated data signal given from the modulator within a range of a predetermined change width, and a recording start point of the modulated data signal given from the modulator, A recording control unit including a second delay unit for changing the change within a range of a change width larger than the predetermined change range; and a first delay unit and a second delay unit for recording information on a recording medium. A selector for selecting one of the functions, and dummy data generating means for generating dummy data to be added to the modulated data signal, wherein the dummy data is generated in accordance with a change in a recording start point of the modulated data signal. Recording and reproducing apparatus of the optical information recording medium characterized by varying the length of the data.