JP2004087104A - Recorder, recording method, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recorder in which decrease in the rewritable frequency of a recording medium is suppressed even when the same data is repeatedly recording on the same position of a recording medium. <P>SOLUTION: An optical disk device 101 records modulated data onto a rewritable recording medium and comprises: a modulation section 105 modulating the data in accordance with a specified modulation rule; a parameter value change section 102 changing at least one parameter value of the specified modulation rule; and a recording section 127 recording the modulated data on the recording medium in accordance with the specified modulation rule. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a recording apparatus and a recording method for recording data on a rewritable recording medium, and a rewritable recording medium.

In recent years, various digital recording media have been developed. As a conventional digital recording medium, for example, a rewritable optical disk such as a DVD-RW is known. A DVD-RW can normally be rewritten about 1,000 times, and is used for recording video and audio and recording computer data.

The DVD-RW employs 8/16 modulation as a modulation rule for recording data. In 8/16 modulation, 8-bit data symbols are converted to 16-bit codewords. There are a plurality of codewords for one data symbol, and it is determined which codeword is to be selected from the plurality of codewords in consideration of state information and DSV (Digital \ Sum \ Value).

The DSV is obtained by obtaining a CDS (Code Word Digital Sum) for each codeword based on the NRZI (Non Return to Zero Inverted) conversion of the selected codeword, and adding these CDSs.

The selection of the codeword is performed in consideration of the DSV of the codeword following the codeword to be currently selected.

Demodulation is performed by converting the current codeword (16 bits) into an 8-bit data symbol with reference to the state information bits (2 bits) indicated by the next codeword. When data recording is started, the initial value of the state information is set to a predetermined fixed value, and the initial value of the DSV is set to 0.

However, according to the above-described technique, when the same data is repeatedly recorded at the same position on the optical disk, marks of the same pattern are recorded at the same position on the optical disk. When a mark of the same pattern is recorded at the same position on the optical disk, a portion where the melting and solidification is repeated many times due to the recording of the mark and a portion where the mark is not recorded and the portion is not melted occur. In the boundary region between the portion where the melting and solidification are repeated and the portion where the melting and solidification are not repeated, the recording thin film is likely to have a defect. Since such a defect spreads before and after the mark, there is a problem in that the quality of the reproduced signal is deteriorated and the number of rewritable times of the optical disc is reduced.

The present invention has been made in view of the above problems, and has a recording apparatus, a recording method, and a recording method capable of suppressing a decrease in the number of rewritable times of an optical disk even when the same data is repeatedly recorded at the same position on the optical disk. The purpose is to provide a medium.

A recording device according to the present invention is a recording device that records modulated data on a rewritable recording medium, comprising: a modulation unit that modulates data according to a predetermined modulation rule; and at least one parameter value of the predetermined modulation rule. And a recording unit that records data modulated according to the predetermined modulation rule on the recording medium, thereby achieving the above object.

The predetermined modulation rule may be a state-type modulation, and one of the at least one parameter value may be an initial state value.

The predetermined modulation rule uses a digital sum value, and one of the at least one parameter value may be an initial value of the digital sum value.

The parameter value changing unit may change the at least one parameter value at random.

The parameter value changing unit may change the at least one parameter value in a predetermined order.

The apparatus further includes a storage unit that stores a previously used parameter value, wherein the parameter value change unit randomly selects a parameter value to be set from parameter values different from the parameter values stored in the storage unit. May be.

A recording method according to the present invention is a recording method for recording modulated data on a rewritable recording medium, the method comprising: modulating data according to a predetermined modulation rule; and at least one parameter value of the predetermined modulation rule. Changing, and recording the data modulated according to the predetermined modulation rule on the recording medium, thereby achieving the above object.

The recording medium of the present invention is a rewritable recording medium on which modulation data is recorded, wherein the modulation data is obtained by modulating data according to a predetermined modulation rule, and at least one of the predetermined modulation rules is provided. The parameter values can be changed, thereby achieving the above objective.

A recording apparatus according to the present invention is a recording apparatus that starts recording data based on an end position of data recorded on a rewritable recording medium, and includes a target for a deviation amount of a data recording position from a predetermined reference position. A parameter value changing unit that changes a parameter value indicating the value, and the predetermined reference position such that a deviation amount of the data recording position from the predetermined reference position approaches the target value as the data recording progresses. And a recording unit that records the data on the recording medium at the recording position of the data, thereby achieving the object described above.

The parameter value changing unit may change the parameter value at random.

The parameter value change unit may change the parameter values in a predetermined order.

The apparatus further includes a storage unit that stores a previously used parameter value, wherein the parameter value change unit randomly selects a parameter value to be set from parameter values different from the parameter values stored in the storage unit. May be.

A recording method according to the present invention is a recording method for starting data recording based on the end position of data recorded on a rewritable recording medium, and includes a method for setting a target deviation amount of a data recording position from a predetermined reference position. Changing the parameter value indicating the value, and as the recording of the data proceeds, the amount of deviation of the data recording position from the predetermined reference position approaches the target value, so that the deviation from the predetermined reference position The method includes a step of changing a shift amount of a data recording position and a step of recording the data on the recording medium at the data recording position, thereby achieving the above object.

The recording medium of the present invention is a rewritable recording medium on which data is recorded, wherein a recording start position of the data is determined based on an end position of data recorded on the recording medium, The recording position of is determined so that the amount of deviation of the recording position of the data from a predetermined reference position approaches a target value as the recording of the data proceeds, and the parameter value indicating the target value can be changed. Thus, the above object is achieved.

According to the present invention, even when it is required to repeatedly record the same data at the same position on a recording medium, the recording is performed while changing the recording pattern, or the recording is performed while changing the recording position. Becomes possible. As a result, the deterioration of the recording thin film of the recording medium can be suppressed, and the decrease in the number of rewritable times of the recording medium can be suppressed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited by the embodiment.

(Embodiment 1)
As an optical disk to be recorded and reproduced by the optical disk device according to the first embodiment, an optical disk compliant with the DVD-RW (Digital Versatile Disk-Rewriteable) standard will be described as an example. First, the DVD-RW will be described below.

(DVD-RW)
FIG. 1 is a configuration diagram showing a configuration of an optical disk conforming to the DVD-RW standard. This optical disk has a recording groove (groove track) formed on a spiral. The recording of data on the optical disk is performed by irradiating a groove track with a light beam to form a recording mark having a changed optical characteristic of a recording film made of a phase change material or the like.

The data to be recorded is composed of a minimum unit of error correction called an ECC (Error Correction Code) block. The ECC block is composed of 16 sectors, and each sector is composed of 26 frames. Each frame is a code obtained by 8/16 modulating a 2-byte synchronization signal and 91-byte data (that is, a code of 1488T in which a sync portion (SY) of 32T and a data portion (DATA) of 1456T). It consists of. Here, 1T indicates the unit time length of a recording mark, and corresponds to 38.2 ns (1 / (26.16 MHz)) at the standard speed of DVD-RW.

The sync portion is composed of a code including “a recording mark having a width of 14T and a space having a width of 4T (an area between recording marks)” or a code having a space having a width of 14T and a recording mark having a width of 4T. The first frame (frame 0) of each sector is provided with 4-byte address information called a data ID and a 2-byte ID error detection code called an IED (ID \ Error \ Detection \ code). The groove track has a wobble of a predetermined frequency. The frequency of this wobble is about 140.6 KHz at the standard speed, and by multiplying the frequency of the wobble by 186 (140.6 KHz × 186 = 26.16 MHz), a clock signal having a unit time length of a recording mark can be obtained. it can. In other words, one wobble has a period of 186T, and one frame (1488T) has eight wobbles.

On the optical disk, land pre-pits (LPP: Land @ Pre-Pit) having a convex shape when viewed from the light beam irradiation surface are provided on land tracks between the groove tracks as recording position references and physical address information. A pit called) is previously embedded in the manufacturing process. The land pre-pit is associated with the groove track on the inner circumferential side, and is located at the vertex of the wobble of the groove track on the inner circumferential side.

に お い て Of the 26 frames constituting the sector, the even frames are called EVEN frames and the odd frames are called ODD frames. In particular, frame 0 is called an EVEN sync frame, and frame 1 is called an ODD sync frame. Basically, a 3-bit LPP code is arranged at the vertex position of the first three wobbles of the eight wobbles of the EVEN frame. FIG. 2 shows the meaning of the LPP code. However, when the inner LPP code and the outer LPP code overlap each other when viewed from the groove track, the outer LPP code is added to the ODD frame in order to prevent interference (cross talk) between the LPP codes. It is to be shifted and arranged. Since 13 LPP codes are defined for one sector, 1 bit of sync code and 12 bits of LPP information can be obtained for each sector by inversely converting each LPP code using the table of FIG. .

FIG. 3 is a configuration diagram showing a configuration of LPP information. The LPP information is grouped in units of ECC blocks (16 sectors). Of the 12-bit LPP information obtained for each sector, the first 4 bits (bit 1 to bit 4) are called RA (Relative @ Address) and indicate the sector number in the ECC block. The remaining 8 bits (bit5 to bit12) are called DATA and indicate two pairs of error correction codes (parities) and two pairs of physical address information (ECC block addresses).

FIG. 4 is a timing chart showing the linking operation. When recording data on an optical disk, recording is performed at a circumferential position where a land prepit at the beginning of each frame and a recording mark or space of 14T width included in a sync part of recording data overlap. Recording is performed using an ECC block as a minimum unit, and recording start and end are at the 18th byte of the first frame of the first sector of the ECC block. Combining already recorded data and recording new data is called linking. If linking fails, data discontinuity occurs. FIG. 5A shows an example in which a gap occurs between data that has already been recorded and data that is to be newly recorded, resulting in discontinuity of data. FIG. 5B shows an example in which data discontinuity occurs because data to be newly recorded has been overwritten on data that has already been recorded. In order to prevent such discontinuity of data from occurring, linking requires high precision for the recording position.

(Optical disk device)
FIG. 6 is a block diagram illustrating a schematic configuration of the optical disc device 101 according to Embodiment 1 of the present invention.

The optical disc device 101 includes a modulation unit 105 that modulates data according to a predetermined modulation rule (for example, 8/16 modulation), a parameter value change unit 102 that changes at least one parameter value of the predetermined modulation rule, and a predetermined value. And a recording unit 127 that records data modulated according to the modulation rule on the optical disc 100. Thus, the optical disk device 101 functions as a recording device that records modulated data on the optical disk 100.

{For example, the parameter value changing unit 102 changes at least one parameter value each time new data is to be recorded on the optical disc 100. The parameter value changing unit 102 may change at least one parameter value at random or in a predetermined order. By changing at least one parameter value, it is possible to convert the same data to different modulation data. As a result, when it is required to repeatedly record the same data at the same position, instead of repeatedly recording the same data at the same position, different modulation data may be repeatedly recorded at the same position. Become. As a result, it is possible to suppress the deterioration of the recording thin film of the optical disc 100 and the decrease in the number of rewritable times of the optical disc 100.

As the parameter value, an arbitrary value that can convert the same data to different modulation data by changing the value can be used. For example, when the predetermined modulation rule is state-type modulation, the parameter value may be an initial value of the state. Alternatively, when the predetermined modulation rule uses a digital sum value (DSV), the parameter value may be an initial value of the digital sum value or a target value of the digital sum value. It may be a value. Alternatively, an initial state value and an initial digital sum value (or target value) may be used in combination as at least one parameter value.

(4) The configuration of the optical disk device 101 will be described in more detail.

FIG. 7 is a block diagram showing the configuration of the optical disk device 101.

The optical disk device 101 includes a head 112, a reproducing unit 113, a demodulating unit 114, a system control unit 115, a main converting unit 116, a sub converting unit 117, NRZI converting units 118 and 119, a CDS calculating unit 120, 121, a DSV comparison unit 122, a run length determination unit 123, a state selector 124, a code word selector 125, a parallel-serial (P / S) conversion unit 126, and a recording unit 127.

(4) The optical disk device 101 records data on the optical disk 100 in the format shown in FIG. The optical disk device 101 reproduces data recorded on the optical disk 100.

The head 112 irradiates the optical disc 100 with a light beam and detects reflected light from the optical disc 100, thereby outputting data recorded on the optical disc 100 as an analog modulation signal. The reproducing unit 113 outputs a reproduced signal by performing an analog-to-digital conversion on the analog modulated signal output from the head 112. The demodulation unit 114 outputs a demodulated signal by demodulating the reproduction signal output from the reproduction unit 113. The demodulated signal is output to system control section 115. The system control unit 115 outputs control signals (for example, a sync gate signal and a data gate signal) for controlling the data pattern generation processing. The sync gate signal and the data gate signal are output to the main converter 116 and the sub converter 117.

FIG. 8 is a block diagram showing a schematic configuration of the system control unit 115. As shown in FIG.

The system control unit 115 includes a DSV initial value changing unit 103 that changes the initial value of the DSV, and a state initial value changing unit 104 that changes the initial value of the state. For example, the DSV initial value changing unit 103 may randomly set the DSV initial value every time new data is to be recorded on the optical disc 100. For example, the DSV initial value changing unit 103 may randomly select one value from a predetermined number of candidate values such as 0, 1, -1 or calculate the DSV initial value using a predetermined calculation formula. May be. Further, the state initial value changing unit 104 may randomly select one of a plurality of states each time new data is to be recorded on the optical disc 100.

The main conversion unit 116 and the sub-conversion unit 117 will be described with reference to FIG.

The main conversion unit 116 has a plurality of conversion tables inside. These plurality of conversion tables include the main conversion table shown in FIG. 9A and the main conversion table shown in FIG. 10B.

The sub-conversion unit 117 has a plurality of conversion tables inside. These plurality of conversion tables include the sub conversion table shown in FIG. 9B and the sub conversion table shown in FIG. 10C.

When the sync gate signal output from the system control unit 115 is enabled, the main conversion unit 116 converts a sync number into a sync code using the main conversion table shown in FIG. 10B, and the sub conversion unit 117 The sync number is converted into the sync code by using the sub conversion table shown in FIG. 10C.

When the data gate signal output from the system control unit 115 is enabled, the main conversion unit 116 converts a data symbol into a code word and a next state code using the main conversion table shown in FIG. 9A, The sub-conversion unit 117 converts a data symbol into a code word and a next state code using the sub-conversion table shown in FIG. 9B.

FIG. 9A is a diagram showing a configuration of a main conversion table of 8/16 modulation as an example of a main conversion table for the data part. FIG. 9B is a diagram illustrating a configuration of a sub-conversion table of 8/16 modulation as an example of a sub-conversion table for a data part.

Each of the main conversion table (FIG. 9A) and the sub conversion table (FIG. 9B) has four tables indicating states 1 to 4, respectively. Each of the four tables includes a code word and a next state for each data symbol. The codeword indicates a codeword to be selected during the current data symbol conversion. The next state indicates a state to be selected at the time of the next data symbol conversion. The next state is used to maintain the run length limit of the codeword connection, and is used to specify state information bits used in demodulation.

In the 8/16 modulation, a sub conversion table is prepared only for data symbols 0 to 87, and for 88 or more data symbols, the main conversion table is used instead of the state 1 table of the sub conversion table. The table of state 4 of the main conversion table is used instead of the table of state 2 of the sub conversion table, and the table of state 3 of the main conversion table is used instead of the table of state 3 of the sub conversion table. A table is used, and the table of state 1 of the main conversion table is used instead of the table of state 4 of the sub conversion table. Therefore, when selecting the sub-conversion table, the run length limit may not be satisfied. Here, the run length limit is a limit on the number of bits “0” existing between a certain bit “1” and the next appearing bit “1”. This is to limit the interval to be equal to or longer than the minimum inversion interval and equal to or shorter than the maximum inversion interval.

Each codeword contains state information bits based on the state of the conversion table used. This state information bit is referred to when demodulating data. In the examples shown in FIGS. 9A and 9B, the 0th and 12th bits of the code word correspond to the state information bits. In the case of state 1 or state 4, the state information bits are "0,0", "0,1", "1,0", or "1,1". That is, in this case, the state information bit is don't care. In the case of state 2, the state information bit is "0, 0". In the case of state 3, the state information bit is “0, 1”, “1, 0”, or “1, 1”.

In FIGS. 9A and 9B, the code word having the next state of 1 or 4 has only one corresponding data symbol, and the table is configured so that the data symbol can be specified without referring to the state information bit. . On the other hand, a code word having a next state of 2 or 3 may have a plurality of corresponding data symbols. Therefore, the data symbol (8 bits) is specified by the code word (16 bits) and the state information bits (2 bits) included in the next code word. That is, for a given codeword, a data symbol for that codeword can be obtained by referring to the state information bits included in the next codeword.

FIG. 10A is a diagram showing the configuration of a table indicating the correspondence between frame numbers and sync numbers. FIG. 10B is a diagram illustrating an example of a configuration of a main conversion table for the sync unit. FIG. 10C is a diagram illustrating an example of a configuration of a sub-conversion table for the sync unit.

The sync code is selected using a sync number designated for each frame number shown in FIG. 10A. Each of the main conversion table (FIG. 10B) and the sub conversion table (FIG. 10C) has a table indicating state 1 / state 2 and a table indicating state 3 / state 4. That is, state 1 and state 2 use the same table. Similarly, state 3 and state 4 use the same table. The state (ie, next state) of the next codeword of the sync section is always 1.

Each sync code contains a state information bit. This state information bit is referred to when demodulating a code word modulated immediately before the sync code. In the examples shown in FIGS. 10B and 10C, the 0th and 12th bits of the sync code correspond to state information bits. In the case of state 1 or state 2, the state information bit is "0,0". In the case of state 3 or state 4, the state information bit is “1, 0”. The relationship between the state of the sink unit and the state information bits is the same as the relationship between the state of the data unit and the state information bits.

As described above, the optical disk device 101 is configured to be able to change the initial value of the state. Therefore, each time a new data symbol is to be recorded on the optical disc 100, it is possible to change the way of state transition. As a result, even when it is requested to record the same data symbol at the same position on the optical disc 100, different recording patterns can be recorded at the same position on the optical disc 100.

Next, with reference to FIG. 7 again, description of each unit of the optical disc device 101 will be continued. In the following description, for convenience, the sync code and the codeword output from the main conversion unit 116 are referred to as a main conversion code, and the next state output from the main conversion unit 116 is referred to as a main conversion state. Similarly, the sync code and the code word output from the sub-conversion unit 117 are called a sub-conversion code, and the next state output from the sub-conversion unit 117 is called a sub-conversion state.

NRZI conversion section 118 performs NRZI conversion on the main conversion code. NRZI conversion section 119 performs NRZI conversion on the sub conversion code.

CDS calculation section 120 calculates the CDS based on the output from NRZI conversion section 118, and outputs the calculation result as CDS _main . CDS calculation section 121 calculates the CDS based on the output from NRZI conversion section 119, and outputs the calculation result as CDS _sub .

The run length determination unit 123 determines whether the run length at the data connection part satisfies the run length limit of the minimum polarity inversion interval of 10 bits based on the output of the NRZI conversion unit 119 and the output of the codeword selector 125. I do. The run length determining unit 123 outputs “H” (high level signal) when it is determined that the run length limit is satisfied, and outputs “L” (low level) when it is determined that the run length limit is not satisfied. Signal).

The DSV comparison unit 122 sets the sum of the current DSVs as DSV _total . When the output of the run length determination unit 123 is “L”, the DSV comparison unit 122 outputs “L” and substitutes (DSV _total + CDS _main ) for DSV _total . When the output of the run length determination unit 123 is “H”, the DSV comparison unit 122 is “L” only when the absolute value of (DSV _total + CDS _main ) is equal to or less than the absolute value of (DSV _total + CDS _sub ). Is output, and (DSV _total + CDS _main ) is substituted for DSV _total . In other cases, the DSV comparison unit 122 outputs “H” and substitutes (DSV _total + CDS _sub ) for DSV _total . The value of DSV _total is reset by the DSV initial value changing unit 103. The reset timing is, for example, when new data is to be recorded on the optical disc 100. The reset value is, for example, a random value.

Thus, the optical disk device 101 is configured to be able to change the initial value of DSV (the value at which DSV _total is reset). Therefore, each time a new data symbol is to be recorded on the optical disc 100, the method of selecting the main conversion table and the sub conversion table can be changed. As a result, even when it is requested to record the same data symbol at the same position on the optical disc 100, different recording patterns can be recorded at the same position on the optical disc 100. However, if the absolute value of the initial value of the DSV is too large, only the same recording pattern will be selected for the same data symbol. This is because DSV control operates to reduce the absolute value of DSV. For this reason, the initial value of the DSV is preferably within ± 4 (within a range of −4 or more and +4 or less).

The state selector 124 outputs the main conversion state as the next state when the output from the DSV comparison unit 122 is “L”, and outputs the sub conversion state when the output from the DSV comparison unit 122 is “H”. Is output as the next state. The next state output from the state selector 124 is input to the main conversion unit 116 and the sub conversion unit 117, respectively, and is used when selecting the next conversion table.

The codeword selector 125 selectively outputs the output from the NRZI converter 118 when the output of the DSV comparator 122 is “L”, and performs the NRZI conversion when the output of the DSV comparator 122 is “H”. The output from the unit 119 is selectively output.

That is, the codeword selector 125 outputs the sync code or the codeword converted by the conversion table in which the absolute value of the DSV becomes smaller. Thereby, the DC component of the NRZI signal can be suppressed.

The parallel-serial conversion unit 126 converts the parallel data from the codeword selector 125 into serial data, and outputs the serial data to the recording unit 127. The recording unit 127 generates an optical conversion signal according to the serial data output from the parallel-serial conversion unit 126, and records the data on the optical disc 100 via the head 112.

As described above, the main conversion unit 116, the sub conversion unit 117, the NRZI conversion units 118 and 119, the CDS calculation units 120 and 121, the DSV comparison unit 122, the run length determination unit 123, the state selector 124, the code word selector 125, The serial (P / S) converter 126 functions as the modulator 105 (FIG. 6) that modulates data according to a predetermined modulation rule (for example, 8/16 modulation). System control section 115 functions as parameter value changing section 102 (FIG. 6) for changing at least one parameter value of the predetermined modulation rule.

Next, the operation of the optical disk device 101 will be described with reference to a flowchart. In the 8/16 modulation of the data section and the sync section, the main conversion table and the sub conversion table are selectively used so that the DSV value becomes a predetermined value.

FIG. 11 is a flowchart showing a processing procedure of 8/16 modulation in the optical disk device 101. In this process, first, the initial value of the DSV and the initial value of the state are set at random (S1). Thus, even when the same data is repeatedly recorded, the recording pattern can be changed, and a decrease in the number of recordable times can be suppressed.

Next, a sync code to be recorded in the sync section or a codeword to be recorded in the data section is generated using the main conversion table and the sub conversion table (S3). That is, when the sync code is recorded in the sync section, the sync number corresponding to the frame number shown in FIG. 10A is converted into the sync code using the main conversion table shown in FIG. 10B and the sub conversion table shown in FIG. 10C. I do. When a codeword is recorded in the data part, the data symbol is converted into a codeword using the main conversion table shown in FIG. 9A and the sub conversion table shown in FIG. 9B.

In each case, which state is used is determined based on the next state determined at the time of the previous conversion.

The CDS is calculated based on the NRZI conversion of the sync code or codeword obtained by the conversion using the main conversion table, and the result is set as the CDS _main . The CDS is calculated based on the NRZI-converted sync code or codeword obtained by the conversion using the sub-conversion table, and the result is set as the CDS _sub (S4).

Next, for the sync code or code word obtained by the conversion using the sub-conversion table, the run length at the connection with the previously processed sync code or code word is calculated, and the run length is determined to be a predetermined length. It is determined whether the constraint is satisfied (S5). When the run length limit is satisfied, the process proceeds to step S6, and when the run length limit is not satisfied, the process proceeds to step S7. As described above, it is determined whether or not only the sync code or the codeword obtained by the conversion using the sub conversion table satisfies the run length restriction, in the conversion using the main conversion table. Is always satisfied, whereas the conversion using the sub conversion table may not satisfy the run length limit.

Therefore, as a result of determining whether or not the run length limit is satisfied, if it is determined that the run length limit is not satisfied, conversion is performed using the main conversion table. This makes it possible to reliably satisfy the run length limitation of 8/16 modulation. In step S6, the absolute value of the value obtained by adding the CDS _main to the integrated DSV and the absolute value of the value obtained by adding the CDS _sub to the integrated DSV are compared. If the absolute value of the value obtained by adding the CDS _main to the DSV is equal to or smaller than the absolute value of the value obtained by adding the CDS _sub to the DSV, the process proceeds to step S7. On the other hand, when the absolute value of the value obtained by adding the CDS _main to the DSV is larger than the absolute value of the value obtained by adding the CDS _sub to the DSV, the process proceeds to step S9.

In step S7, a value obtained by adding the CDS _main to the existing DSV is set as a new DSV. Thereafter, a sync code or a code word obtained by conversion using the main conversion table is selected as a code to be recorded (S8).

In step S9, a value obtained by adding the CDS _sub to the existing DSV is set as a new DSV. Thereafter, a sync code or a code word obtained by the conversion using the sub conversion table is selected as a code to be recorded (S10).

Next, it is determined whether or not the recording of all the data has been completed (S11). If the recording has been completed, the process is terminated. If the recording has not been completed, the process returns to step S2.

As described above, according to the first embodiment of the present invention, the initial value of the DSV and the initial value of the state can be randomly changed every time new data is to be recorded on the optical disc. Therefore, even when the same data is repeatedly rewritten, the recording pattern can be changed. As a result, a decrease in the number of rewritable times can be suppressed.

(Embodiment 2)
FIG. 12 is a block diagram showing a schematic configuration of an optical disc device 201 according to Embodiment 2 of the present invention.

The optical disc apparatus 201 includes a parameter value changing unit 203 that changes a parameter value indicating a target value of a shift amount of a data recording position with respect to a predetermined reference position, and a data recording position with respect to the predetermined reference position as data recording progresses. Includes a shift amount changing unit 202 that changes the shift amount of the data recording position with respect to a predetermined reference position so that the shift amount approaches the target value, and a recording unit 204 that records data on the optical disc 100 at the data recording position. . The optical disc device 201 functions as a recording device that starts recording data based on the end position of the data recorded on the optical disc 100.

{For example, the parameter value changing unit 203 changes the parameter value each time new data is to be recorded on the optical disc 100. The parameter value changing unit 203 may change the parameter values randomly or in a predetermined order. By changing the parameter value, the same data can be recorded at different positions. Thus, when it is required to repeatedly record the same data at the same position, instead of repeatedly recording the same data at the same position, the same data is recorded at a different position. As a result, it is possible to suppress the deterioration of the recording thin film of the optical disc 100 and the decrease in the number of rewritable times of the optical disc 100.

(4) The configuration of the optical disk device 201 will be described in more detail.

FIG. 13 is a block diagram showing the configuration of the optical disk device 201.

The optical disc device 201 includes a spindle motor 212, a pickup 213, a motor driver 214, a power control circuit 215, a light beam drive circuit 216, a reproduction amplifier 217, a prepit reproduction circuit 218, a wobble reproduction circuit 219, A reproduction circuit 220, a reproduction clock generation circuit 221, a prepit window protection circuit 222, a prepit sync detection circuit 223, a prepit demodulation circuit 224, a prepit address extraction circuit 225, a data sync detection circuit 226, Sync window protection circuit 227, 8/16 demodulation circuit 228, data ID extraction circuit 229, recording clock generation circuit 230, lock detection circuit 231, system control unit 232, recording control circuit 233, error correction circuit 234 and 8/16 And a control circuit 235.

The spindle motor 212 rotates the optical disc 100 at a predetermined rotation frequency. The spindle motor 212 is driven by a motor driver 214.

(4) The pickup 213 irradiates the optical disc 100 with a light beam having a predetermined reproducing power. The light beam output from the pickup 213 is controlled based on a drive signal output from the light beam drive circuit 216. The light beam drive circuit 216 is controlled based on a reproduction power control signal output from the power control circuit 215. The reflected light from the optical disc 100 depends on the optical and physical characteristics of the recording film of the optical disc 100 irradiated with the light beam. The reflected light from the optical disk 100 enters the pickup 213.

The pickup 213 includes a plurality of light receiving circuits (not shown). Each of the plurality of light receiving circuits converts the amount of light reflected from the optical disc 100 into an electric signal.

The regenerative amplifier 217 generates a sum signal (RF (Radio Frequency) signal) by adding the electrical signals output from the plurality of light receiving circuits, and amplifies the RF signal and the light receiving signal divided substantially in parallel with the track. A difference signal (push-pull signal) is generated from the electric signal output from the circuit. The RF signal is output to the data reproduction circuit 220. The push-pull signal is output to the pre-pit reproducing circuit 218 and the wobble reproducing circuit 219.

The pre-pit reproducing circuit 218 includes a comparator (not shown) for comparing the level of the push-pull signal with the slice level (generally an intermediate value between the maximum level of the land pre-pit portion and the maximum level of the wobble fluctuation portion). The pre-pit reproducing circuit 218 outputs an H-level pre-pit signal when the level of the push-pull signal is higher than the slice level, and outputs an L-level pre-pit signal when the level of the push-pull signal is lower than the slice level.

The wobble reproducing circuit 219 includes a BPF (Band Pass Filter) (not shown) through which a wobble frequency (approximately 140.6 kHz at a standard speed) component passes, a level of a signal output from the BPF, and a slice level (of a wobble portion). And a comparator (not shown) for comparing the output with a substantially intermediate value of the amplitude. By passing the push-pull signal through the BPF, noise components and land pre-pit components can be removed from the push-pull signal. The wobble reproduction circuit 219 outputs an H level wobble signal when the level of the signal output from the BPF is higher than the slice level, and outputs an L level wobble when the level of the signal output from the BPF is lower than the slice level. Output a signal.

The data reproducing circuit 220 compares a level of the RF signal with a slice level (a value that makes an integral value of an H level in a predetermined section substantially equal to an integral value of an L level in a predetermined section) (not shown). )including. The data reproduction circuit 220 outputs an H level data reproduction signal when the level of the RF signal is higher than the slice level, and outputs an L level data reproduction signal when the level of the RF signal is lower than the slice level.

The reproduction clock generation circuit 221 controls the minimum width (3T) of the H level or the L level of the data reproduction signal to correspond to three periods of the reproduction clock, and sets the maximum width (14T) of the H level or the L level of the data reproduction signal. ) Controls the frequency of the reproduction clock so as to correspond to 14 periods of the reproduction clock, thereby generating a reproduction clock having a frequency of 1T.

The pre-pit window protection circuit 222 predicts the position of the pre-pit signal to be detected next based on the position of the previously detected pre-pit signal, and excludes the pre-pit signal detected at a position other than the predicted position. This reduces false detection of prepits.

The prepit sync detection circuit 223 extracts a prepit sync signal corresponding to the first land prepit of the LPP code from the prepit signal output from the prepit window protection circuit 222.

The pre-pit demodulation circuit 224 synchronizes with the pre-pit sync signal and converts the pre-pit signal into pre-pit information according to the table shown in FIG.

The pre-pit address extraction circuit 225 synchronizes with the EVEN sync or the ODD sync in the pre-pit information, obtains RA and LPP information, stores the LPP information in a memory based on the RA, performs predetermined error correction, Extract the pit address.

The data sync detection circuit 226 synchronizes the data reproduction signal with the timing of the reproduction clock, and outputs a sync code including 14T4T (14T width recording mark and 4T width space, or 14T width space and 4T width recording mark). Detect and output a data sync detection signal.

The data sync window protection circuit 227 predicts the position of the next data sync detection signal to be detected based on the position of the previously detected data sync detection signal, and excludes the data sync detection signal detected at a position other than the predicted position. I do. Thereby, erroneous detection of the data sink is reduced.

The # 8/16 demodulation circuit 228 performs 8/16 demodulation based on the data sync detection signal output from the data sync window protection circuit 227, and outputs demodulated data.

The data ID extraction circuit 229 extracts a data ID from the demodulated data.

(4) The recording clock generation circuit 230 generates a recording clock. The frequency of the recording clock is controlled by the wobble signal and the pre-pit signal. The configuration of the recording clock generation circuit 230 will be described later.

The lock detection circuit 231 detects that the recording clock is within a predetermined frequency range and is stable, and outputs a lock signal.

The system control unit 232 refers to the extracted pre-pit address or data ID, and when the pickup 213 reaches a corresponding address where data is to be recorded and detects a lock signal indicating that the recording clock is stable, the recording is performed. It instructs the recording control circuit 233 to start the operation.

FIG. 14 is a block diagram showing a schematic configuration of the system control unit 232.

The system control unit 232 includes a parameter value changing unit 203 that changes a parameter value indicating a target value of a deviation amount of a data recording position from a predetermined reference position. For example, the parameter value changing unit 203 may randomly set a parameter value each time new data is to be recorded on the optical disc 100. The parameter value set by the parameter value changing unit 203 is output to the recording clock generation circuit 230.

再 び Referring again to FIG. 13, in response to a recording instruction from system control unit 232, recording control circuit 233 determines whether or not data has been recorded immediately before the recording start point. If data is not recorded immediately before the recording start point, the recording control circuit 233 determines a recording start point based on the pre-pit signal and generates a recording gate signal. When data is recorded immediately before the recording start point, the recording control circuit 233 determines the recording start point based on the data sync detection signal and generates a recording gate signal.

The error correction circuit 234 adds an error correction code to data to be recorded in response to the recording gate signal.

The 8/16 modulation circuit 235 generates a modulation signal by performing 8/16 modulation on the output from the error correction circuit 234, and synchronizes the modulation signal with a recording clock and outputs the modulated signal.

The power control circuit 215 outputs a recording power control signal to the light beam driving circuit 216 in response to the recording gate signal.

The light beam drive circuit 216 multi-pulses the modulation signal based on a predetermined write strategy and outputs a drive signal according to the recording power control signal.

The pickup 213 converts the drive signal into a light beam, and irradiates the light beam to the recording film of the optical disc 100. The optical characteristics of the recording film irradiated with the light beam change. As a result, a recording mark is formed on the recording film.

The recording clock generation circuit 230 includes a first timing signal generator 236, a second timing signal generator 237, a phase difference detector 238, a filter 239, and a PLL (Phase Locked Loop) circuit 240.

The first timing signal generator 236 outputs a first rectangular wave. The first timing signal generator 236 includes a counter (not shown) that counts the number of edges (rising edge or falling edge) of the recording clock, and H when the count value of the counter reaches a predetermined value (B). A coincidence detecting circuit (not shown) for outputting a signal of a level and outputting a signal of an L level when the count value of the counter reaches a predetermined value (C). The count value of the counter is preset to a predetermined value (A) in response to the pre-pit sync signal. If the pre-pit sync signal is not input to the first timing signal generator 236, the first timing signal generator 236 changes the count value of the counter after the count value of the counter reaches the predetermined value (D). Reset to "0". This counter is preset in response to a pre-pit sync signal regardless of non-recording (recording gate signal is not output) and recording (recording gate signal is output).

The second timing signal generator 237 outputs a second rectangular wave. The second timing signal generator 237 includes a counter (not shown) for counting the number of edges (rising edge or falling edge) of the recording clock, and H when the count value of the counter reaches a predetermined value (B). A coincidence detecting circuit (not shown) for outputting a signal of a level and outputting a signal of an L level when the count value of the counter reaches a predetermined value (C). The count value of the counter is preset to a predetermined value (E) in response to the data sync detection signal. When the data sync detection signal is not input to the second timing signal generator 237, the second timing signal generator 236 changes the count value of the counter after the count value of the counter reaches the predetermined value (D). Reset to "0". This counter is preset in response to the data sync detection signal only when recording is not performed (recording gate signal is not output).

The predetermined values (A) and (E) are the phase of the first rectangular wave and the second phase when the land prepit and the center of the 14T-width recording mark or space of the data sync are recorded. It is designed as a value such that the difference from the phase of the rectangular wave becomes zero. The predetermined value (D) is a multiple of the length of one wobble cycle.

The phase difference detector 238 operates only when recording (recording gate signal is output), and outputs a first phase difference signal indicating the difference between the phase of the first rectangular wave and the phase of the second rectangular wave. I do.

The filter 239 outputs a signal in which the amount of time change of the first phase difference signal is limited as a correction amount signal. The filter 239 can be realized using, for example, an LPF. The first time difference of the phase difference signal is limited by the response speed of the data reproducing PLL of the device for reproducing the optical disk recorded by the optical disk device according to the present embodiment with the response speed that the reproduction clock generation can sufficiently follow. Done to do so.

Here, it is generally considered that the response speed of the PLL is preferably 9 kHz or more. If the speed at which the deviation of the recording position is changed from the start of recording, in other words, the speed at which the recording position is offset from the start of recording is too fast, the PLL during data reproduction cannot follow the time axis fluctuation of the recording signal and the reproduction error occurs. May be caused. On the other hand, in order to increase the effect of preventing the same data from being written to the same position, it is desirable that the speed at which the shift amount of the recording position is changed from the start of recording be faster. Therefore, it is desirable that the speed at which the shift amount of the recording position is changed is about 9 kHz or less, which does not exceed the response speed of the reproduction PLL.

The PLL circuit 240 controls the frequency of the recording clock based on the pre-pit signal and the wobble signal, and outputs the correction amount signal (ie, the phase difference between the first rectangular wave and the second rectangular wave) from the filter 239 to the system. The frequency of the recording clock is controlled so as to approach the parameter value from the control unit 232.

FIG. 15 is a block diagram showing an example of the configuration of the PLL circuit 240.

The PLL circuit 240 includes, for example, a noise filter 241, a phase comparator 242, a charge pump 243, a first LPF 244, a VCO 245, a frequency divider 246, a phase difference detector 247, and an adder 248. A second LPF 249 and a phase shifter 250 are included.

The noise filter 241 removes, as noise, H pulses and L pulses of a predetermined amount or less included in the wobble signal.

The phase comparator 242 compares the phase of the wobble signal from which noise has been removed by the noise filter 241 with the phase of the phase-shifted frequency-divided clock output from the phase shifter 250, and indicates a second phase difference indicating the comparison result. Output a signal.

The charge pump 243 converts the second phase difference signal output from the phase comparator 242 into a voltage level signal.

(1) The first LPF 244 removes a high-frequency component from the voltage level signal output from the charge pump 243.

The #VCO 245 oscillates at a frequency corresponding to the voltage level signal from which the high-frequency component has been removed by the first LPF 244, and outputs a recording clock.

The frequency divider 246 outputs a divided clock by dividing the recording clock by 186.

The phase difference detector 247 detects the difference between the phase of the pre-pit signal and the phase of the wobble signal each time the pre-pit signal is input, and outputs a third phase difference signal indicating the detection result.

The second LPF 249 removes a high-frequency component from the third phase difference signal output from the phase difference detector 247, and outputs the third phase difference signal with a limited amount of time change.

The adder 248 adds the signal output from the second LPF 249, the correction amount signal, and the parameter value passed through the inverter to generate an addition correction amount signal.

(4) The phase shifter 250 shifts the phase of the frequency-divided clock in accordance with the addition correction amount signal, and outputs a phase-shifted frequency-divided clock.

As described above, the system control unit 232 functions as the parameter value changing unit 203 (FIG. 12) that changes the parameter value indicating the target value of the amount of deviation of the data recording position from the predetermined reference position. The recording clock generation circuit 230 changes the shift amount of the data recording position from the predetermined reference position so that the shift amount of the data recording position from the predetermined reference position approaches the target value as the data recording progresses. It functions as the shift amount changing unit 202 (FIG. 12). The power control circuit 215 and the light beam drive circuit 216 function as a recording unit 204 (FIG. 12) that records data on the optical disc 100 at a data recording position.

The optical disk device 201 synchronizes the frequency or phase of the recording clock with the frequency or phase of the reproduction clock obtained based on the data recorded on the optical disk 100, starts recording data, and then starts recording the data with a predetermined time constant. Change frequency or phase. This makes it possible to shift the position where data is actually recorded with respect to the position where data should be originally recorded (predetermined reference position), and as the recording proceeds, the position where data should be originally recorded (predetermined reference position). Position) can be changed. The position where the data should be originally recorded (predetermined reference position) is, for example, a position where the land prepit and the center of the 14T-width recording mark or space of the data sync overlap. The allowable range of the deviation amount from the position where the data should be originally recorded (predetermined reference position) is, for example, 2T.

FIG. 16 shows a state in which after data recording is started, the amount of deviation from a position where data should be originally recorded (predetermined reference position) changes as data recording progresses. As the data recording progresses, the amount of deviation finally reached (target value of the amount of deviation) falls within the allowable range (for example, 2T) of the amount of deviation from the position where recording should be originally performed (predetermined reference position). Is set by the parameter value changing unit 203.

As the data recording progresses, the finally arrived shift amount (target value of the shift amount) is randomly selected from a predetermined number of candidates such as 2T, T, 0, -T, and -2T. Or may be selected in a predetermined order. Alternatively, a shift amount (a target value of the shift amount) which finally reaches as data recording progresses may be calculated according to a predetermined calculation formula.

In FIG. 16, a solid line A shows how the shift amount changes when the target value of the shift amount is set to 2T, and a solid line B shows that the shift amount when the target value of the shift amount is set to T. The solid line C shows how the shift amount changes when the target value of the shift amount is set to -T, and the solid line D shows the target value of the shift amount set at -2T. The state in which the deviation amount changes when the operation is performed is shown.

FIG. 17A is a timing chart showing the operation of the first timing signal generator 236 (FIG. 13).

(4) In response to the pre-pit sync signal output from the pre-pit sync detection circuit 223, the count value of the counter incorporated in the first timing signal generator 236 is preset to "24". The counter counts the number of edges (rising edge or falling edge) of the recording clock. The first timing signal generator 236 outputs an L-level signal when the count value of the counter reaches “46”, and outputs an H-level signal when the count value of the counter reaches “139”. When the count value of the counter reaches “185”, the count value of the counter is reset to “0”. Thus, the first timing signal generator 236 outputs the first rectangular wave having the period 186T in which the L level and the H level are alternately repeated.

FIG. 17B is a timing chart showing the operation of the second timing signal generator 237 (FIG. 13).

The count value of the counter incorporated in the second timing signal generator 237 is preset to “32” in response to the data sync detection signal output from the data sync detection circuit 226. The counter counts the number of edges (rising edge or falling edge) of the recording clock. The second timing signal generator 237 outputs an L level signal when the count value of the counter reaches “46”, and outputs an H level signal when the count value of the counter reaches “139”. When the count value of the counter reaches “185”, the count value of the counter is reset to “0”. In this manner, the second timing signal generator 237 outputs the second rectangular wave having the period 186T in which the L level and the H level are alternately repeated.

When there is no shift in the data recording position between the first rectangular wave and the second rectangular wave, the difference between the phase of the first rectangular wave and the phase of the second rectangular wave is “0”. Has been adjusted as follows. Therefore, when the data recording position is shifted forward, a second rectangular wave having a phase advanced from the phase of the first rectangular wave is output, and when the data recording position is shifted backward, , A second rectangular wave having a phase delayed from the phase of the first rectangular wave is output.

FIG. 18 is a timing chart showing the timing of starting data recording.

Upon receiving the recording instruction output from the system control unit 232, the recording control circuit 233 operates according to a timer (not shown) that operates in response to the recording clock, and changes the recording gate signal in response to the data sync detection signal. Output (start up).

(4) When the recording gate signal is output, each circuit in the optical disk device 201 starts the recording operation, and the presetting of the counter value of the counter built in the second timing signal generator 237 is prohibited.

If the data recording position is shifted forward, immediately after the data recording is started, a second rectangular wave having a phase advanced from the phase of the first rectangular wave is output. On the other hand, when the recording position of the data is shifted backward, immediately after the recording of the data is started, a second rectangular wave having a phase delayed from the phase of the first rectangular wave is output. After data recording is started, the phase of the first rectangular wave and the phase of the second rectangular wave change according to the control of the recording shift. The phase difference detector 238 detects a difference between the phase of the first rectangular wave and the phase of the second rectangular wave, and outputs a first phase difference signal indicating the detection result. The filter 239 outputs, as a correction amount signal, a signal in which the time change amount of the first phase difference signal is limited.

Before starting the data recording, the PLL circuit 240 is in a state of controlling the frequency of the recording clock according to the pre-pit signal and the wobble signal. After the data recording is started, the frequency of the recording clock is controlled by adding the correction amount signal and the parameter value to the loop of the PLL circuit 240. Specifically, when the data recording position is shifted backward, the frequency of the recording clock may be lowered so that the phase of the second rectangular wave is delayed from the phase of the first rectangular wave. Conversely, when the data recording position is shifted forward, the frequency of the recording clock may be increased so that the phase of the second rectangular wave advances from the phase of the first rectangular wave.

After starting the data recording, this operation is repeated until the amount of deviation from the position where the data should be originally recorded (predetermined reference position) reaches the target value (parameter value). Value), the state is switched to a state in which the frequency of the recording clock is controlled according to the pre-pit signal and the wobble signal. Thereby, in the connection part of the previously recorded data and the newly recorded data, since the data is recorded based on the data sync detection signal, the continuity of the data can be ensured, and as the data recording progresses, The shift amount of the data recording position can be changed.

Note that, as an example of the PLL circuit 240, a configuration has been described in which the frequency of the recording clock is controlled according to the pre-pit signal and the wobble signal, but the configuration of the PLL circuit 240 is not limited to this configuration. PLL circuit 240 may have another configuration. Further, the parameter value may be subtracted from the correction amount signal or the first phase difference signal in advance.

For example, the configuration is such that the phase-shifted frequency-divided clock, which is one input of the phase comparator 242, is further shifted according to the correction amount signal and the parameter value, but the wobble signal after the noise filter 241 that is the other input is further shifted. A shift configuration may be used. The same effect can be obtained by converting the parameter value and the correction amount signal passed through the inverter into a voltage level signal, and then adding the voltage level signal to the output of the charge pump 243 in an analog manner.

As described above, according to the second embodiment of the present invention, the recording of new data is started based on the end position of the data recorded on the optical disk, and the recording of new data is performed as the recording of new data proceeds. The shift amount can be changed so that the shift amount of the position approaches the target value. The target value can be changed each time new data is to be recorded on the optical disc. This makes it possible to record the same data at different positions even if it is required to repeatedly record the same data at the same position. As a result, a decrease in the number of rewritable times of the optical disc can be suppressed.

(Embodiment 3)
FIG. 19 is a block diagram showing a configuration of an optical disc device 301 according to Embodiment 3 of the present invention. The same components as those described in the second embodiment (FIG. 13) are denoted by the same reference numerals.

The optical disc device 301 includes a spindle motor 212, a pickup 213, a motor driver 214, a power control circuit 215, a light beam driving circuit 216, a reproduction amplifier 217, a prepit reproduction circuit 218, a wobble reproduction circuit 219, A reproduction circuit 220, a reproduction clock generation circuit 221, a prepit window protection circuit 222, a prepit sync detection circuit 223, a prepit demodulation circuit 224, a prepit address extraction circuit 225, a data sync detection circuit 226, Sync window protection circuit 227, 8/16 demodulation circuit 228, data ID extraction circuit 229, recording clock generation circuit 250, lock detection circuit 231, system control unit 232, recording control circuit 233, error correction circuit 234 and 8/16 And a control circuit 235.

The recording clock generation circuit 250 includes a PLL circuit 240, a first timer 251, a second timer 252, a subtractor 253, and a filter 239.

The first timer 251 includes a counter (not shown) that counts the number of edges (rising edge or falling edge) of the time clock and outputs the count value as a first timer value. The count value of this counter is preset to a predetermined value in response to the pre-pit sync signal. When the pre-pit sync signal is not input to the first timer 251, the first timer 251 resets the count value of the counter to “0” every frame (1488 counts). This timer is preset in response to the pre-pit sync signal regardless of non-recording (recording gate signal is not output) and recording (recording gate signal is output).

The second timer 252 includes a counter (not shown) that counts the number of edges (rising edge or falling edge) of the time clock and outputs the count value as a second timer value. The count value of this counter is preset to a predetermined value in response to the data sync detection signal. When the data sync detection signal is not input to the second timer 252, the second timer 252 resets the count value of the counter to “0” every frame (1488 counts). This timer is preset in response to the data sync detection signal only when recording is not performed.

で は In the present embodiment, the recording clock is also used as the time clock.

The preset values of the first timer 251 and the second timer 252 are such that the first timer value and the second timer value are equal to each other when the land prepit and the center of the 14T-width recording mark or space of the data sync are recorded. Are designed so that the difference from the timer value is zero.

The subtracter 253 operates only when recording (recording gate signal is output), and outputs a difference signal indicating a difference between the first timer value and the second timer value.

The filter 239 outputs, as a correction amount signal, a signal in which the time change amount of the difference signal output from the subtracter 253 is limited. The filter 239 can be realized using, for example, an LPF. The time change amount of the difference signal is limited in order to set the response speed of the data reproducing PLL of the device for reproducing the optical disk recorded by the optical disk device according to the present embodiment to a response speed such that reproduction clock generation can sufficiently follow. Is

The PLL circuit 240 controls the frequency of the recording clock based on the pre-pit signal and the wobble signal, and outputs the correction amount signal (ie, the difference between the first timer value and the second timer value) from the filter 239 to the system. The frequency of the recording clock is controlled so as to approach the parameter value from the control unit 232.

@PLL circuit 240 may have, for example, the same configuration as PLL circuit 240 (FIG. 15) described in the second embodiment. Thereby, in the connection part of the previously recorded data and the newly recorded data, since the data is recorded based on the data sync detection signal, the continuity of the data can be ensured, and as the data recording progresses, The shift amount of the data recording position can be changed.

(4) Since the correction amount can be derived by obtaining the timer value, there is an advantage that the recording clock generation circuit 250 can be constituted only by a digital circuit. In particular, the operations of the subtractor 253, the filter 239, and the like can be realized by software processing. By doing so, the circuit scale of the recording clock generation circuit 250 can be reduced, and the filter characteristics can be easily changed.

As described above, in the second and third embodiments, when the recorded data exists before the position where the data is to be recorded, the data is recorded based on the data sync detection signal. The recording start point does not deviate from the data. After data recording is started, the data recording position is shifted with a predetermined time constant. In this point, the recording methods of the second and third embodiments are different from the conventional SPS (Start \ Position \ Shift) in which the recording start point itself is shifted. In this SPS, discontinuity occurs in linking because the recording start point itself is shifted. On the other hand, in the recording methods according to the second and third embodiments, since there is no shift in the recording start point, discontinuity in linking can be prevented. Further, in the recording methods of the second and third embodiments, since the data recording position is finally shifted, the same effect as the SPS can be obtained.

(Other embodiments)
In the above-described embodiment, the DVD-RW is taken as an example of the recording medium, but another rewritable optical disk or a recording medium other than the optical disk may be used instead of the DVD-RW. Further, another modulation rule may be used instead of the 8/16 modulation. In addition, a storage unit for storing previously used parameter values is provided, and the parameter value changing units 102 and 203, the DSV initial value changing unit 103, and the state initial value changing unit 104 are different from the previously used parameter values. A parameter value to be set may be randomly selected from the parameter values.

Further, the parameter value changing units 102 and 203 and the DSV initial value changing unit 103 and the state initial value changing unit 104 are configured such that state 3 is next to state 1 and state 2 is next, or next to DSV = 0. A predetermined order is stored, such as DSV = 1, DSV = −1, or a displacement amount of 2T next to a displacement amount of 0, and a displacement amount of −1T next to the displacement amount. A predetermined order is stored every time recording is started. The parameter values may be switched and set in order. Further, either the DSV initial value changing unit 103 or the state initial value changing unit 104 may be omitted.

Embodiment 1 may be applied to Embodiment 2 or 3. For example, the parameter value changing unit 102 according to the first embodiment may be provided in the optical disk devices 201 and 301 according to the second or third embodiment. Further, the DSV initial value changing unit 103 and the state initial value changing unit 104 of the first embodiment are provided in the system control unit 232 of the second or third embodiment so that the DSV initial value and the state initial value are changed. Is also good. Thus, since the pattern recorded together with the recording position can be changed, a decrease in the number of rewritable times of the optical disk can be further suppressed.

According to the present invention, even when it is required to repeatedly record the same data at the same position on a recording medium, the recording is performed while changing the recording pattern, or the recording is performed while changing the recording position. Becomes possible. As a result, the deterioration of the recording thin film of the recording medium can be suppressed, and the decrease in the number of rewritable times of the recording medium can be suppressed. Therefore, the present invention is useful as a recording device and a recording method for recording data on a rewritable recording medium, a rewritable recording medium, and the like.

Configuration diagram showing the configuration of an optical disk compliant with the DVD-RW standard The figure which shows the conversion table of LPP code Configuration diagram showing the configuration of LPP information Timing diagram showing linking operation Diagram showing an example in which data discontinuity has occurred because a gap has occurred between already recorded data and newly recorded data Diagram showing an example in which data discontinuity has occurred because data to be newly recorded has been overwritten on data already recorded 1 is a block diagram illustrating a schematic configuration of an optical disc device 101 according to Embodiment 1 of the present invention. FIG. 2 is a block diagram illustrating a configuration of the optical disc device 101. FIG. 2 is a block diagram showing a schematic configuration of a system control unit 115. Diagram showing an example of the main conversion table Diagram showing an example of a sub conversion table FIG. 4 is a diagram illustrating an example of a table indicating a correspondence relationship between a frame number and a sync number; Diagram showing an example of the main conversion table Diagram showing an example of a sub conversion table 8 is a flowchart showing a processing procedure of 8/16 modulation in the optical disc device 101 FIG. 4 is a block diagram showing a schematic configuration of an optical disc device 201 according to Embodiment 2 of the present invention. FIG. 2 is a block diagram illustrating a configuration of the optical disc device 201. FIG. 2 is a block diagram illustrating a schematic configuration of a system control unit 232. FIG. 2 is a block diagram illustrating an example of a configuration of a PLL circuit 240. FIG. 7 is a diagram illustrating a state in which a deviation amount from a position where data is originally to be recorded (a predetermined reference position) changes as data recording proceeds after data recording is started. Timing diagram showing operation of first timing signal generator 236 (FIG. 13) Timing diagram showing operation of first timing signal generator 237 (FIG. 13) Timing diagram showing timing for starting data recording FIG. 4 is a block diagram showing a configuration of an optical disc device 301 according to Embodiment 3 of the present invention.

Explanation of reference numerals

REFERENCE SIGNS LIST 100 optical disk 101, 201, 301 optical disk device 102, 203 parameter value changing unit 103 DSV initial value changing unit 104 state initial value changing unit 115, 232 system control unit 202 shift amount changing unit 230 recording clock generation circuit

Claims (14)

A recording device that records modulated data on a rewritable recording medium,
A modulator for modulating data according to a predetermined modulation rule,
A parameter value changing unit that changes at least one parameter value of the predetermined modulation rule;
A recording unit for recording data modulated according to the predetermined modulation rule on the recording medium. The recording apparatus according to claim 1, wherein the predetermined modulation rule is a state-type modulation, and one of the at least one parameter value is an initial state value. The recording apparatus according to claim 1, wherein the predetermined modulation rule uses a digital sum value, and one of the at least one parameter value is an initial value of the digital sum value. The recording apparatus according to claim 1, wherein the parameter value changing unit randomly changes the at least one parameter value. The recording apparatus according to claim 1, wherein the parameter value changing unit changes the at least one parameter value in a predetermined order. Further comprising a storage unit for storing previously used parameter values,
The recording apparatus according to claim 1, wherein the parameter value changing unit randomly selects a parameter value to be set from parameter values different from the parameter values stored in the storage unit. A recording method for recording modulated data on a rewritable recording medium,
Modulating the data according to a predetermined modulation rule;
Changing at least one parameter value of the predetermined modulation rule;
Recording the data modulated according to the predetermined modulation rule on the recording medium. A rewritable recording medium on which modulated data is recorded,
The recording medium, wherein the modulation data is obtained by modulating data according to a predetermined modulation rule, and at least one parameter value of the predetermined modulation rule is changeable. A recording device that starts recording data based on an end position of data recorded on a rewritable recording medium,
A parameter value changing unit that changes a parameter value indicating a target value of a shift amount of a data recording position from a predetermined reference position,
A shift that changes the shift amount of the data recording position from the predetermined reference position so that the shift amount of the data recording position from the predetermined reference position approaches the target value as the data recording progresses. An amount changing section;
A recording unit for recording the data on the recording medium at a recording position of the data. The recording apparatus according to claim 9, wherein the parameter value changing unit changes the parameter value at random. The recording apparatus according to claim 9, wherein the parameter value changing unit changes the parameter values in a predetermined order. Further comprising a storage unit for storing previously used parameter values,
The recording apparatus according to claim 9, wherein the parameter value changing unit randomly selects a parameter value to be set from parameter values different from the parameter values stored in the storage unit. A recording method for starting recording data based on an end position of data recorded on a rewritable recording medium,
Changing a parameter value indicating a target value of a shift amount of a data recording position from a predetermined reference position,
Changing the shift amount of the data recording position from the predetermined reference position so that the shift amount of the data recording position from the predetermined reference position approaches the target value as the recording of the data proceeds When,
Recording the data on the recording medium at the recording position of the data. A rewritable recording medium on which data is recorded,
The recording start position of the data is determined based on the end position of the data recorded on the recording medium,
The recording position of the data is determined such that a deviation amount of the recording position of the data from a predetermined reference position approaches a target value as the recording of the data proceeds,
A recording medium, wherein a parameter value indicating the target value is changeable.

Images