JP2002042343A - Information signal recording method, reproducing method and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem conventionally that inability to perform exact recording operation gives large influence to the detection of a prepit by the large power output of a laser for the writing at recording. SOLUTION: In an optical disk, the recording operation is performed by inserting the margin bit MB into a recording information signal, as shown in (B). Furthermore, the inserting position of this margin bit MB into the information signal is arranged so as to come to the position of the prepit (reproduction prepit is shown in (A)) of adjacent groove parts and also the bit pattern of the margin bit MB is set to be the value, as shown in (C) ('0' in this case) so as that erasure period TE of a write pulse for writing become as shown in (D). By this arrangement, the influence given by the write pulse to the read- out of the prepit information at recording operation is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an information signal recording method,
The present invention relates to a reproducing method and a recording medium, and more particularly to an information signal recording method for recording an information signal at a high density on a recording medium such as an optical disk, a reproducing method for reproducing a recorded information signal on a recording medium, and a recording medium on which the information signal is recorded.

[0002]

2. Description of the Related Art Conventionally, pre-pit information is recorded in advance, and as a recording medium on which information can be rewritten based on the pre-pit information, a DVD-R (DVD-Recordable) is used.
e), DVD-RW (DVD-Rewritable) is known. Hereinafter, the relationship between prepits and recording signals of an optical disc based on the DVD-RW standard will be described as an example.

As described in Japanese Patent Application Laid-Open No. 10-293926, for example, a groove or land is formed in a spiral shape on an optical disc of the above standard, and one or both sides of the groove are continuous. In addition, there is a land between grooves adjacent to each other in the radial direction of the disk, and auxiliary information is recorded in advance in the land as pre-pits. For this optical disc, an information signal is recorded in a groove portion.

Further, at the time of recording on the optical disk, reflected light obtained by irradiating the optical disk with a light beam is received by a well-known two-segment photodetector, and the obtained two light-receiving signals are subjected to a well-known push-pull method. The auxiliary information is acquired by detecting the pre-pit signal, and a wobble signal is extracted from the groove to extract a recording clock signal synchronized with the rotation of the optical disk. Further, based on the difference signal obtained by the push-pull method, the information beam is recorded by causing the light beam spot to follow and scan the groove portion.

The information signal to be recorded has a unit length T corresponding to a pit interval defined by a recording format.
Is recorded in units of 1488 times the sync frame. This sync frame is defined so that synchronization information Sync having a length of 14T from the beginning is provided. On the other hand, the auxiliary information recorded by the pre-pits is located in one sync frame of the recording signal recorded in the groove, in the land adjacent to the recording position of the synchronization information Sync, and at the top of the wobble. The pre-pit recording cycle is 2 sync frames.

That is, the synchronization information Sync of the sync frame of the information signal to be recorded is such that the pre-pit can be accommodated.
The data is encoded and recorded in synchronization with the recording clock signal. In addition to the position adjacent to the above-mentioned synchronization information Sync, the pre-pit may also exist at the vertex of another wobble adjacent to the recording information following the synchronization information Sync, and is used for information such as a physical address. are doing.

[0007]

In the conventional information signal recording method described above, when the interference between the pre-pit and the recording information signal is considered, the pre-pit Sync at the head of the pre-pit is 14T from the head of the sync frame of the recording signal. By synchronizing with the center of the flat synchronization information Sync recording period, mutual interference is reduced.

However, the other pre-pits directly interfere with the random recording signal, causing the pre-pits to have a reduced level and a phase shift.
False discrimination increases, and as a result, correct recording or reproduction cannot be performed. Conversely, noise is superimposed on a recording signal, so that an error rate deteriorates. This tendency becomes more conspicuous as the recording density increases, so a method of reducing mutual interference has been desired.

Further, at the time of recording, a large power output of the writing laser has a great influence on the detection of prepits, and there is a problem that correct recording cannot be performed.

The present invention has been made in view of the above points, and has as its object to provide an information signal recording method, a reproducing method, and a recording medium capable of reducing interference between a recording signal and a prepit.

[0011]

According to the present invention, in order to achieve the above object, a groove or land is formed concentrically or spirally, and one or both sides of the groove or land are continuously formed. It is formed with wobbles, and a land or a groove exists between adjacent grooves or lands, and auxiliary information is recorded in the land or the groove in advance as prepits at predetermined intervals. In an information signal recording method for recording an information signal on a groove or a land of a medium, the information signal has a margin so that a margin bit of a predetermined bit pattern is recorded at a position adjacent to a prepit in the groove or the land. The recording is performed by inserting bits. According to the present invention, it is possible to record a margin bit which does not affect the reading of the pre-pit during a period including the position of the pre-pit.

In order to achieve the above object, the recording medium of the present invention has a groove or a land formed concentrically or spirally, and one or both sides of the groove or the land are continuously formed. It is formed with wobbles, and there is a land or groove between adjacent groove or land, and auxiliary information is recorded in advance in the land or groove as pre-pits at predetermined intervals, In a recording medium in which an information signal is recorded in a groove or a land, a margin bit of a predetermined bit pattern is recorded at a position adjacent to a prepit in the groove or the land. According to the present invention, it is possible to provide a recording medium in which margin bits that do not affect reading of prepits are recorded during a period including the position of prepits.

In order to achieve the above object, according to the information signal reproducing method of the present invention, a groove or a land is formed concentrically or spirally and one or both sides of the groove or the land are continuous. A wobble is formed, and a land portion or a groove portion exists between adjacent groove portions or land portions. Auxiliary information is previously recorded at predetermined intervals as pre-pits on the land portion or the groove portion. In an information signal reproducing method for reproducing an information signal from a recording medium in which margin bits are inserted into an information signal and recorded such that a margin bit of a predetermined bit pattern is adjacent to a prepit in a groove portion or a land portion, The pre-pit signal obtained by detecting the pre-pit signal included in the reproduction signal from the recording medium Hazuki, to determine the position of the margin bits, ignoring the reproduced signal from the position of the margin bits,
The information signal is reproduced.

According to the present invention, since the margin bits which do not affect the reading of the pre-pits are reproduced during the period including the position of the pre-pits, the original information signal can be reproduced by ignoring the margin bits.

[0015]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a positional relationship among a reproduction pre-pit, a recording signal and a write pulse for writing in the first embodiment of the information signal recording method according to the present invention. In this embodiment, a groove portion is formed concentrically or spirally and one or both sides of the groove portion are continuously formed with a wobble, and a groove portion adjacent in the disk radial direction is formed. Between the land portions, auxiliary information is recorded in advance as pre-pits in the land portions, and the information signal is recorded in the groove portion. For example, the present invention is applied to an optical disc such as a rewritable DVD-R or DVD-RW. Things.

In this embodiment, this optical disc
As shown in FIG. 1B, a margin bit MB is inserted into a recording information signal for recording. The margin bit MB is inserted into the information signal at a pre-bit position of an adjacent groove portion. In addition, the bit pattern of the margin bit MB is changed to the erase period (erase period) of the write pulse for writing shown in FIG.
The value is set to a value as shown in FIG. 1C (“0” in this case) so as to be TE. FIG. 1A shows a reproduced pre-pit signal.

FIG. 1C shows an example of a waveform of an information signal (recording data) before NRZI conversion. As described above, a margin bit MB is inserted in the erase period TE of a write pulse. Here, the erase period of the write pulse shown in FIG. 1D is when the write pulse is at a level higher than Pe level from Pe level, and the relationship between this write pulse and the recording data is publicly known and will be described later.

Here, the relationship between the pre-pits and the margin bits will be further described. In FIG. 2A, the relationship between the pre-pits and the margin bits is shown in FIG.
As shown in (B), before the NRZI conversion, the margin bits MB inserted into the information signal have some "0" s consecutively between the first bit Pa and the last bit Pb. , A total of Nm bits, and conforms to the run-length restriction rule (d, k). Note that the run-length restriction rule (d, k) is a rule that a minimum of d and a maximum of k “0” s are consecutive between “1” and “1”.

As shown in FIG. 2B, immediately before the margin bit MB, the number of "0" continues Nf, and immediately after the margin bit MB, the number of "0" is Nb. Continuous. Further, as shown in FIG. 2A, the number of bits from the leading edge of the pre-pit to the margin bit MB insertion position is N
s.

As can be seen from FIGS. 2A and 2B,
In the middle section of the margin bit MB adjacent to the pre-pit, the sign inversion is not performed, so that the influence of the recording signal on the pre-pit is greatly reduced, and conversely, the influence of the pre-pit on the recording signal (information portion) is also reduced. Bit MB
Is naturally reduced because the distance is increased by the insertion. In addition,
First bit Pa and last bit Pb of margin bit MB
Is appropriately determined by an encoder in the recording apparatus, as described later.

FIG. 3 is a block diagram showing an example of an optical disk apparatus to which the information signal recording method according to the present invention is applied. In FIG. 1, an optical head 11 has a light source, an optical system such as an objective lens, a photodetector, and the like. When recording, a laser drive signal based on recording information data supplied from a laser drive circuit 12 is provided. In accordance with the above, the output power of the light beam from the light source is changed, and the light beam is applied to the information recording surface of the optical disc (not shown) to record the record information data. At the time of reproduction, the optical disk is irradiated with a light beam at a fixed output power (reading power), and the reflected light is received by a photodetector in the optical head 11.

The optical head 11 receives the reflected light of the light beam irradiated on the information recording surface of the optical disk from the information recording surface by a photodetector in the optical head 11 and converts the light into an electric signal. For example, by performing arithmetic processing based on the radial push-pull method, a detection signal carrying a wobble signal of prepits and grooves, recording information data, and the like is generated, and output to the reproduction amplifier 13.

The reproduction amplifier 13 amplifies the pre-pit signal from the land portion and the detection signal carrying the wobble signal of the groove portion output from the optical head 11, and generates an information signal including the pre-pit signal and the wobble signal to generate a recording clock signal. In addition to supplying the amplified signal to the decoder 14, an amplified signal corresponding to the recorded information data is output to the decoder 15 during reproduction. The decoder 15 decodes the input amplified signal to
After the value is converted, the input amplified signal is decoded by 8/16 demodulation and deinterleaving to generate a demodulated signal, and this demodulated signal is output to the central processing unit (CPU) 16.

On the other hand, the recording clock signal generator 14 calculates the maximum wobble signal from the composite signal in which the pre-pit signal is superimposed at a predetermined position (for example, the maximum amplitude position) of the wobble signal included in the information signal supplied from the reproduction amplifier 13. The pre-pit signal is detected and supplied to the pre-pit decoder 17 by comparing with a level larger than the amplitude value, and a wobble signal is extracted by binarizing the composite signal. A clock signal is generated and supplied to the encoder 18, and a rotation control signal is generated based on a difference signal between the recording clock signal and the reference clock signal, and is output to a motor drive system (not shown).

The pre-pit decoder 17 decodes auxiliary information from the supplied pre-pit detection signal,
Output to The CPU 16 performs an interface operation on the recording information data transmitted from a host computer or the like (not shown) so as to capture the recording information data into the recording device, and outputs the input recording information data to the encoder 18.

The encoder 18 performs ECC processing, 8/16 modulation processing and scramble processing using the recording clock signal supplied from the recording clock signal generator 14 as a timing signal, generates a modulated signal, and generates a power control circuit. 19 is output. Further, the encoder 18 performs a process of inserting a margin bit generated as described later into the recording information data based on the pre-pit position information supplied from the recording clock signal generator 14.

The power control circuit 19 converts the waveform of the modulation signal based on the recording clock signal supplied from the recording clock signal generator 14 in order to improve the shape of the recording pit formed on the optical disk. A so-called write strategy process) is performed, and is output to the laser drive circuit 12 as a recording signal. The laser drive circuit 12 includes the optical head 1
1 drives a light source, and outputs a laser drive signal for emitting a light beam with an emission power according to the supplied recording signal. During recording, the CPU 16 acquires address information from the auxiliary information supplied from the pre-pit decoder 17, and controls the entire data recording apparatus so as to record the record information data at a position on the optical disk corresponding to the address information. .

Here, the above write strategy processing is performed by:
A plurality of laser pulses having three different power levels are used. These three power levels are in order from the highest
These are peak power (write power), medium power (erase power), and bias power (read power). The peak power level is indicated by Po in FIGS. 1 (D) and 4 (B). When the optical disk is irradiated with the laser beam having the peak power, the recording film of the optical disk is melted. It becomes an amorphous state in which light reflectance is low. This is used as a recording mark.

The medium power level is indicated by Pe in FIGS. 1D and 4B. When the optical disk is irradiated with the laser light of this medium power, the recording film is brought into a crystalline state. Therefore, when the medium light laser light is irradiated to the portion of the optical disk that was in an amorphous state before the laser light irradiation, the medium changed to a crystalline state, and the portion that was originally in a crystalline state is maintained in a crystalline state as it is. Is done. Therefore, the recording mark can be erased by the above-mentioned medium power laser beam. The level of the bias power is indicated by Pb in FIGS. 1D and 4B, and the recorded information can be read by irradiating the optical disk with the laser light having the bias power. This is because the state of the optical disk is not changed.

Here, the recording data (information signal) before the NRZI conversion shown in FIG. 1C and FIG.
The modulated coded data, and when writing “1”, as shown in FIGS. 1D and 4B, the write pulse is の of the 1-bit width Tw of the recording data. A pulse with a peak power of about 0.5 Tw in length and about 0.5 Tw in width;
The pulse of the bias power having a width of 5 Tw is alternately repeated to suppress heat accumulation during recording. The relationship between FIGS. 4A and 4B is well known.

Here, in the present embodiment, the encoder 1
8, a margin bit is inserted into the information signal (recording data), and a margin bit pattern is set so that the margin bit recording period is a write pulse erasing (erase) period. FIG. 5 shows an internal block diagram of an encoder for realizing each embodiment of the information recording method according to the present invention. 3, the same components as those of FIG. 3 are denoted by the same reference numerals, and the description thereof will be omitted. In FIG. 5, the encoder 1
8 includes a code modulation block 181, a margin bit insertion block 182, and an NRZI converter 183.

The code modulation block 181 and N
The RZI converter 183 is configured in a conventional encoder. The present embodiment is characterized in that a margin bit insertion block 182 is provided between them. The pre-pit position information detected in the recording clock signal generator 14 is supplied to the margin bit insertion block 182, and the recording signal input from the code modulation block 181 based on the pre-pit position information is added to the margin bit insertion block 182.
According to the flowchart shown in FIG.
And insert the appropriate margin bits.

Next, a method of generating margin bits in the first embodiment of the recording method of the present invention will be described with reference to the flowchart of FIG. In determining the first bit Pa and the last bit Pb of the margin bits, (1)
(2) Use DSV control that appropriately controls DC level as much as possible, (3) Invert as little as possible without affecting land pre-pits (LPP), (4) Invert In such a case, the condition of inversion on the rear side as much as possible is satisfied.

That is, in the margin bit insertion block 182 in the encoder 18, first, the number Nf of consecutive "0" immediately before the margin bit of the information signal is smaller than d and the consecutive "0" immediately after the margin bit. Is determined whether or not the number Nb is smaller than d (step 101), and Nf <
If d and Nb <d, both the start bit Pa and the end bit Pb are set to "0" so as to observe the run length restriction rule (d, k) (step 102).

On the other hand, if the condition of step 101 is not satisfied, it is determined whether or not Nf <d (step 10).
3) If Nf <d, it is determined whether or not (Nf + Nm + Nb) is larger than the maximum value k of the run-length limit length (step 104). When determining Nm,
The determination is made on the assumption that Pa and Pb in Nm are both "0" (the same applies hereinafter). When (Nf + Nm + Nb)> k, one of the first bit Pa and the last bit Pb is set to “1” in order to observe the run-length restriction rule, but only Pb is changed to “1” from the condition that the sign is inverted on the rear side as much as possible. "(Step 105). (Nf + Nm + N
If b) is equal to or smaller than k, the run-length restriction rule is followed, so that both the leading bit Pa and the trailing bit Pb are set to "0" (step 106).

When it is determined in step 103 that Nf is not smaller than d, it is determined whether Nb <d (step 107). When Nb <d, (Nf + Nm + N
It is determined whether or not b) is larger than the maximum value k of the run-length limit length (step 108). When the value is large, one of the leading bit Pa and the trailing bit Pb is set to "1" in order to observe the run length restriction rule, but only N is equal to or larger than N, so only Pa is set to "1" (step 109). ). (N
If (f + Nm + Nb) is equal to or less than k, the run-length restriction rule is followed, so that both the leading bit Pa and the trailing bit Pb are set to "0" (step 110).

If it is determined in step 107 that Nb is equal to or greater than d, the number of "0" immediately before the margin bit and the number of "0" immediately after are both equal to or greater than d.
It is determined whether or not (f + Nm + Nb) is greater than the maximum value k of the run-length limit length (step 111). If k is equal to or smaller than k, polarity control is performed (step 112). This polarity control is performed so that the polarity of the flat portion of the bit number Nm−2 following the margin bit Pa before the NRZI conversion becomes the polarity corresponding to the erasing period (in the example of FIG. 1, FIG.
Pa is set to “1” as shown in FIG.
Alternatively, it is set to “0”.

When Pa is set to "1" (PA1), the routine proceeds to step 113, where DSV control is performed, and Pa
Is set to "0" (PA2), the routine proceeds to step 114, where DSV control is performed. In the above-described DSV control, a DSV operation before or after margin bit insertion (in the case of pre-reading) is performed, and based on the operation result, a CV such that the DSV (digital sum value) is reduced.
Select 1 or C2. In the DSV control of step 113, Pa is "1", Pb is set to "1" when C2 is selected (step 115), and Pb is selected when C1 is selected.
b is set to "0" (step 116). In the DSV control of step 114, Pa is “0” for all.
When C2 is selected, Pb is set to “0” (step 11).
7), Pb is set to "1" when C1 is selected (step 11)
8).

In the flowchart of FIG. 6 and the flow chart of FIG. 11 described later, the above-mentioned C1 is a case where it is desired to invert the polarity after the margin bit by one inversion. This is the case when the polarity is maintained.

If it is determined in step 111 that (Nf + Nm + Nb) is equal to or larger than k, it exceeds the maximum value k of the run-length restriction rule, so that (Nf + Nm)> k and (Nm + Nb-1) ≦ k It is determined whether there is any data (step 119). If the condition is satisfied, the sum of the margin bit and the number of “0” immediately before the margin bit is larger than k.
An operation is performed, and C1 or C2 whose DSV is reduced is selected based on the operation result (step 12).
0), when C1 is selected, only the first bit Pa is set to "1" (step 121), and when C2 is selected, both Pa and Pb are set to "1".
1 "(step 122).

If the condition of step 119 is not satisfied, (Nf + Nm-1) ≦ k and (Nm + Nb)
It is determined whether or not> k (step 123). If the condition is satisfied, the polarity control is performed (step 124) because the sum of the margin bit and the number of "0" immediately after the margin bit is larger than k. As described above, this polarity control is performed such that the polarity of the flat portion of the bit number Nm-2 following the margin bit Pa before the NRZI conversion becomes the polarity corresponding to the erasing period (in the example of FIG. Pa is set to “1” or “0”, as shown in FIG.

When Pa is set to "1" (PA1), the routine proceeds to step 126, where Pb is set to "1" and Pa is set to "0".
(PA2), the routine proceeds to step 125, where Pb
Is “1”. When the condition of step 123 is satisfied, there is no room for DSV control, so that only the polarity control is performed as described above. If the condition of step 123 is not satisfied, both Pa and Pb are set to "1" (step 127).

The margin bit insertion block 182 shown in FIG.
The margin bits generated as described above correspond to the pre-pit positions in the information signal (recording data) before NRZI modulation input to the margin bit insertion block 182 as shown in FIG. After being inserted at the timing, it is converted into an NRZI signal by the NRZI converter 183,
The write write pulse is supplied to the power control circuit 19 and converted into a modulated signal based on the recording clock signal supplied from the recording clock signal generator 14 as described above. Is output to the laser drive circuit 12.

As a result, the relationship between the margin bits recorded in the groove portion on the optical disc and the pre-pits and wobbles recorded in advance in the land portion is as shown in FIG. In the figure, SY is synchronization information for one sync block period (the same as the one sync frame period), and is encoded and recorded in synchronization with the recording clock signal so that the leading pre-pit p1 is contained.

The pre-pits p2 and p3 correspond to other wobbles W adjacent to the recording information following the above-mentioned synchronization information SY.
Of the pre-pits p2 and p3
, That is, in the adjacent groove part,
The margin bits m1 and m2 are recorded. This allows
Interference between the pre-pits p2 and p3 and the recorded information can be reduced.

Also, as shown in FIG. 1D, the write write pulse for the margin bit period is set to the medium power rather than the recording period using the conventional peak power by setting the bit pattern of the margin bit. Therefore, the effect of the write pulse on reading the pre-pit information during recording can be reduced.

Even when margin bits are inserted into the recording information signal, if it is not desired to change the integer ratio relationship between the channel bit clock frequency of the information signal to be recorded on the conventional optical disc and the wobble frequency, a basic operation is required. The additional bits added to the recording information signal during one sync block period may be set to a multiple of the number of wobbles during one sync block period. For example, when the number of wobbles in one sync block period is 3, the number of additional bits may be a multiple of 3. FIG. 8 shows the relationship between prepits, wobbles and margin bits at this time. In the figure, the same parts as those in FIG. 7 are denoted by the same reference numerals, and the description thereof will be omitted.

The allocation of the additional bits to the margin bits is free. However, when all the additional bits are to be allocated to the margin bits, candidates for the length of the margin bits include 3T, 6T, 9T, and 12T. What is necessary is to select the most appropriate place while observing the state of interference.
As a result, the frequency of the channel bit clock is always an integral multiple of the wobble frequency.

In FIGS. 7 and 8, a flat portion in the synchronization information SY is drawn so as to be synchronized with the pre-pits. However, it is needless to say that the synchronization information SY may be replaced with a margin bit without being synchronized.

Next, a description will be given of a second embodiment of the information recording method according to the present invention. FIG. 9 shows a positional relationship among a reproduction pre-pit, a recording signal and a write pulse for writing in the second embodiment of the information signal recording method according to the present invention.
In this embodiment, a margin bit MB is inserted into a recording information signal as shown in FIG. 2B on an optical disc for recording.
The insertion position of the B into the information signal is set to the position of the pre-bit in the adjacent groove portion, and the flat portion II in the synchronization information SY in the NRZI-converted recording signal shown in FIG. 9B exists. The bit pattern of the past margin bit is set so that the write pulse for writing at the position is in an erasing period indicated by III in FIG. 9C. FIG. 9A shows a reproduced pre-pit signal.

The synchronization information SY is encoded and recorded in synchronization with the recording clock signal so that the leading pre-pit p1 is accommodated, for example, as shown in FIG. The pre-pits p2 and p3 are present at the vertices of another wobble W adjacent to the record information following the above-mentioned synchronization information SY, and margin bits m1 and m2 are recorded at positions corresponding to the pre-pits p2 and p3. Is done.

Next, a method of generating margin bits in a second embodiment of the recording method of the present invention will be described with reference to the flowcharts of FIGS. 10 and 11, the same processing steps as those in FIG.
The description is omitted. In the second embodiment, when it is determined in step 111 that (Nf + Nm + Nb) is equal to or less than the maximum value k of the run-length limit length, the synchronization signal SYNC (synchronization information SY) is inserted until the next margin bit is inserted.
Is determined (step 13 in FIG. 11).
1) If it does not exist, D is the same as in the first embodiment.
SV control is performed (step 11 in FIG. 11).
4) If it exists, SYNC polarity control is performed (step 132 in FIG. 11).

In the SYNC polarity control, the NRZI
The polarity of the flat portion in the synchronization information SY that appears next in the converted recording data has the polarity corresponding to the erase period III of the write pulse shown in FIG. 9C (in the example of FIG. 9B, “
0 ”) so as to select the first bit Pa and the last bit Pb of the past margin bits of the synchronization information SY. By the SYNC polarity control in step 132, the polarity after the margin bit is obtained by one inversion. Is inverted (C1), Pa = 0 and Pb = 1 are set (step 134 in FIG. 11), and if the polarity is maintained without inversion or twice inversion (C2), Pa = 1 and Pb
= 1 (step 133 in FIG. 11).

In step 119, (Nf +
When it is determined that Nm)> k and (Nm + Nb−1) ≦ k, the sum of the margin bit and the number of “0” immediately before the margin bit is larger than k. It is determined whether or not a synchronization signal SYNC (synchronization information SY) exists before insertion (step 135 in FIG. 11).
If it does not exist, DSV control is performed as in the first embodiment (step 120 in FIG. 11), but if it does exist, SYNC polarity control is performed (FIG. 11).
Step 136).

When the polarity after the margin bit is inverted by one inversion by the SYNC polarity control in step 136 (C1), Pa = 1 and Pb = 0 (step 137 in FIG. 11), no inversion or When the polarity is maintained by inversion twice (C2), Pa = 1,
It is assumed that Pb = 1 (step 137 in FIG. 11).

Further, in step 123, (Nf +
When it is determined that (Nm-1) ≦ k and (Nm + Nb)> k, the sum of the margin bit and the number of “0” immediately after the margin bit is larger than k, and in this case also, the next margin bit It is determined whether or not a synchronization signal SYNC (synchronization information SY) exists before insertion (step 139 in FIG. 11).
If there is, SYNC polarity control is performed (step 140 in FIG. 11).

When the polarity after the margin bit is inverted by one inversion by the SYNC polarity control in step 140 (C1), Pa = 0 and Pb = 1 (step 141 in FIG. 11), no inversion or When the polarity is maintained by inversion twice (C2), Pa = 1,
It is assumed that Pb = 1 (step 142 in FIG. 11). If it is determined in step 139 that the synchronization signal SYNC (synchronization information SY) does not exist before the insertion of the next margin bit, DSV control is performed (step 143 in FIG. 11), and the margin bit is obtained by one inversion. When the subsequent polarity is to be inverted (C1), Pa = 0 and Pb = 1 (step 144 in FIG. 11), no inversion or 2
When the polarity is maintained by the reversal (C2), Pa =
1, Pb = 1 (step 145 in FIG. 11).

As described above, according to the present embodiment, the insertion position of the margin bit MB into the information signal is set to the position of the pre-bit in the adjacent groove portion, and the NRZI conversion shown in FIG. The bit pattern of the past margin bit is set so that the write pulse for writing at the position where the flat portion II in the synchronization information SY in the subsequent recording signal is in an erasing period as indicated by III in FIG. 9C. Is set, it is possible to reduce the influence of the write pulse on reading the pre-pit information during recording.

Next, another embodiment of the main part of the present invention will be described. FIG. 12 shows an internal block diagram of an encoder for realizing another embodiment of the information recording method according to the present invention. In the figure, the same components as those of FIG.
The description is omitted. In FIG. 12, the encoder 18
Is the code modulation block 184 and the NRZI converter 183
Consisting of

In the present embodiment, the code modulation block 184
The feature is that it is provided. The code modulation block 184
The pre-pit position information detected in the recording clock signal generator 14 is supplied together with the recording clock signal. When code modulation is performed on the recording signal input from the CPU 16, the pre-pit position information shown in FIG. After an appropriate margin bit is generated by the method described with reference to the flowchart of FIG. 11, it is inserted at a timing corresponding to the pre-pit position based on the pre-pit position information. In this embodiment, since the code modulation and the insertion of the margin bit are performed at the same time, the DSV control and the like can be shared.

Next, a method of reproducing a recording medium according to the present invention will be described. Although the hardware configuration of the playback device itself is the same as the conventional one, the algorithm of the playback method is slightly different from the conventional one. That is, in the optical disc of the above-described embodiment, as shown in FIG. 7 or FIG. 8, recording is performed by inserting margin bits into the information signal (recording data) so that margin bits are recorded at positions adjacent to the pre-pits. Therefore, at the time of reproduction, based on the pre-pit detection signal obtained by detecting the pre-pit signal included in the reproduction signal, if the signal reproduced from the position of the groove portion corresponding to the pre-pit position is a margin bit By discriminating and ignoring the reproduction signal from this position and decoding the reproduction signal,
The original information signal is reproduced.

The present invention is not limited to the above embodiment. For example, the method of generating margin bits is as follows.
The method is not limited to the method of the flowchart in FIG. 6 or FIG. 10 and FIG. 11. Depending on the system, there may be no run-length restriction or DSV control may not be necessary. The corresponding branch in 11 is eliminated, and the degree of freedom in selection is increased.

Further, the present invention can be applied to an optical disc on which an information signal is recorded on a land portion among the groove portion and the land portion. Further, the present invention is applicable not only to optical disks but also to other media as long as the relationship between the pre-pits and the recording signal is satisfied.

[0064]

As described above, according to the present invention,
A bit pattern of a margin bit is set so that a write pulse in a margin bit period is an erasing period, or a past margin bit pattern is set so that a write pulse in a flat portion in synchronization information is in an erasing period. Thus, the influence of the write pulse on reading the pre-pit information during recording can be reduced.

Further, according to the present invention, during the period including the position of the pre-pit, margin bits which do not affect the reading of the pre-pit are recorded and reproduced, so that interference between the information signal and the pre-pit signal is reduced. In addition, each piece of information can be accurately reproduced. At this time, the pattern of the margin bits depends on the run-length constraint of the recording signal and the D.
By determining in consideration of the SV, the DC component of the signal can be reduced, and a recording / reproducing system advantageous for reproduction can be constructed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a positional relationship among a reproduction pre-pit, a recording signal, and a write pulse for writing in an information signal recording method according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between prepits and margin bits in each embodiment of the information signal recording method according to the present invention.

FIG. 3 is a block diagram of an example of an optical disk device to which the information signal recording method according to the present invention is applied.

FIG. 4 is a diagram showing an example of a general relationship between recording data and a write pulse in a rewritable optical disk.

FIG. 5 is an internal block diagram of an encoder for realizing one embodiment of the information recording method according to the present invention.

FIG. 6 is a flowchart illustrating a method of generating a margin bit generated according to the first embodiment of the present invention and inserted into a recording signal.

FIG. 7 is a diagram illustrating an example of a relationship between prepits, wobbles, and margin bits.

FIG. 8 is a diagram illustrating another example of the relationship between prepits, wobbles, and margin bits.

FIG. 9 is a diagram showing a positional relationship among a reproduction pre-pit, a recording signal, and a write pulse for writing in an information signal recording method according to a second embodiment of the present invention.

FIG. 10 is a flowchart (part 1) illustrating a method of generating margin bits generated according to the second embodiment of the present invention and inserted into a recording signal.

FIG. 11 is a flowchart (part 2) illustrating a method of generating a margin bit generated according to the second embodiment of the present invention and inserted into a recording signal.

FIG. 12 is an internal block diagram of an encoder for realizing another embodiment of the information recording method according to the present invention.

[Explanation of symbols]

 Reference Signs List 11 optical head 14 recording clock signal generator 16 central processing unit (CPU) 18 encoder 19 power control circuit 181 code modulation block 182 margin bit insertion block 183 NRZI converter 184 code modulation block with margin bit insertion function SY synchronization information MB margin Bit Pa First bit of margin bit Pb Last bit of margin bit Po Peak power (write power) level Pe Medium power (erase power) level Pb Bias power (read power) level

Claims (6)

[Claims] 1. A groove portion or land portion is formed concentrically or spirally, and one or both sides of the groove portion or land portion are continuously formed with wobbles, and adjacent groove portions or lands are formed. A land portion or a groove portion exists between the portions, and an information signal is recorded in the groove portion or the land portion of the recording medium in which auxiliary information is recorded at predetermined intervals as pre-pits in the land portion or the groove portion. In the information signal recording method, the margin bit is inserted into the information signal so that a margin bit is recorded at a position adjacent to the prepit in the groove portion or the land portion, and a write pulse for writing in the margin bit period is written. Is a bit pattern of the margin bit so that Information signal recording method and setting. 2. A groove portion or land portion is formed concentrically or spirally, and one or both sides of the groove portion or land portion are continuously formed with wobbles, and an adjacent groove portion or land is formed. A land portion or a groove portion exists between the portions, and an information signal is recorded in the groove portion or the land portion of the recording medium in which auxiliary information is recorded at predetermined intervals as pre-pits in the land portion or the groove portion. In the information signal recording method, the margin bit is inserted into the information signal so that a margin bit is recorded at a position adjacent to the prepit in the groove portion or the land portion, and the prepit is present during a synchronization signal period. The margin is set so that the write pulse for writing at the position Information signal recording method characterized by setting the Tsu bets bit pattern. 3. The bit pattern of the margin bit corresponds to a run-length limit of the information signal, and
3. The information signal recording method according to claim 1, wherein a bit pattern that does not affect the reading of the prepit is selected. 4. The predetermined bit pattern of the margin bit is selected in consideration of the DSV of the information signal, and a bit pattern that does not affect the reading of the pre-pit is selected. Information signal recording method described. 5. A groove portion or a land portion is formed concentrically or spirally, and one or both sides of the groove portion or the land portion are continuously formed with wobbles, and an adjacent groove portion or a land is formed. A recording medium in which a land or a groove exists between the parts, auxiliary information is recorded in the land or the groove in advance as pre-pits at predetermined intervals, and an information signal is recorded in the groove or the land. A margin bit is inserted into the information signal, the margin bit is recorded at a position adjacent to the prepit in the groove portion or the land portion, and a write pulse for writing in the margin bit period becomes an erasing period Or the writing of the position where the pre-pit exists during the synchronization signal period As use write pulse is erase period, a recording medium, wherein the bit pattern of the merging bits is recorded is set. 6. A groove portion or land portion is formed concentrically or spirally, and one or both sides of the groove portion or land portion are continuously formed with wobbles, and an adjacent groove portion or land is formed. There is a land or groove between the parts, and auxiliary information is recorded in the land or groove in advance as pre-pits at predetermined intervals, and a margin bit is adjacent to the pre-pit in the groove or land. So that the margin bit is inserted into the information signal and recorded, and the write pulse for writing in the margin bit period is in an erasing period, or writing is performed in a position where the pre-pit exists in a synchronization signal period. The bit pattern of the margin bit is set so that the write pulse for An information signal reproducing method for reproducing the information signal from a recording medium on which is set and recorded, based on a pre-pit signal obtained by detecting a signal of the pre-pit included in a reproduction signal from the recording medium, An information signal reproducing method, comprising: judging a position of the margin bit, ignoring a reproduction signal from the position of the margin bit, and reproducing the information signal.