CN100385515C - Error correction encoding method, and apparatus and method for recording data using the same - Google Patents

Abstract

A method of recording data, comprising: forming a plurality of codewords by error correction coding a predetermined amount of input data according to a predetermined method; and recording data including the plurality of codewords to the small-sized optical disc in a recording unit having a length shorter than a predetermined track of an inner circumferential area of the small-sized optical disc.

Description

Error correction encoding method and device and method for recording data using the encoding method

technical field

The present invention relates to an error correction encoding method, and a method and device for recording data using the error correction encoding method.

Background technique

Information recording media include magnetic disks such as floppy disks and hard disks, magnetic tapes, semiconductor memory chips such as ROM and RAM, and optical disks such as CDs and DVDs.

The recording capacity of an optical disc has been rapidly increased with the development of semiconductor technology and signal processing technology, and the price of the optical disc is relatively low.

Information recorded on an optical disc is recorded in units of blocks having a predetermined size. A block unit in which data is recorded is also a basic unit of error correction coding (ECC). The size of an ECC block used in a conventional optical disc is generally 32K bytes or 64K bytes.

Attempts have been made to use optical disks as information recording media for simultaneously recording and/or reproducing both sound and images using portable electronic devices such as video cameras.

However, there are some disadvantages to using optical discs in portable electronic devices like video cameras. That is, the size of the optical disc, typically 80mm or 120mm, is too large for a video camera, and with a traditionally sized optical disc, the power consumption is too high.

Therefore, in order to use an optical disc as an information recording medium of a portable electronic device, an optical disc having a smaller size but higher recording density than conventional optical discs is required.

When recording and reproducing data in a conventional size of ECC block unit on a small-sized optical disc having a diameter of 30 to 50 mm, a problem may occur in error correction when reproducing the recorded data.

For error correction coding in conventional DVDs, Reed-Solomon generating codes (RSPC) are used. In the case of RSPC, the ECC block unit includes 416 recording frames corresponding to 32K user data. A sync frame includes 1488 channel bits, and a channel bit is 0.133 μm long. The length of a unit ECC block in the track direction is therefore 82,328.064 μm, which is equal to the circumference of a circle with a radius of 13.1 mm. Therefore, when an ECC block unit used in a conventional DVD is recorded in an area within a radius of 13.1 mm, the ECC block unit will occupy more than one track. Therefore, when recording conventional ECC block units to a small-sized optical disc having a diameter of 30 to 50 mm, error correction data is inevitably recorded on two or more tracks.

FIG. 1 is a schematic diagram showing an inner peripheral area of a small-sized optical disc on which data having a conventional ECC block unit is recorded.

Referring to FIG. 1, when an ECC block unit of 64 Kbytes is recorded from an inner peripheral area to an outer peripheral area in a data recording area within a radius of 6 mm from the center of a small-sized optical disc, the conventional ECC block unit is changed from point A to Record to point D. That is, when an ECC block unit is recorded in the innermost circumferential area of a small-sized optical disc, the ECC block unit is recorded on two tracks, thereby generating an overlapping area of the ECC block unit in the radial direction. If there is a scratch in the radial direction of the overlapping area on which the unit ECC block is recorded, serious errors may be generated in the ECC block unit, thereby significantly reducing the error correction capability.

That is, if the ECC block unit is recorded not on only one track but on two tracks of a small-sized optical disc, if there is any defect such as a scratch on the inner peripheral area, the recorded ECC block unit Error correction capability is significantly reduced.

This problem occurs not only when RSPC is used as the ECC format, but also when Long Distance Code (LDC) is used.

According to U.S. Patent No. 6,367,049, an ECC block unit includes 304 LDCs generated from RS (248, 216, 33) and 24 Burst Indicator Subcodes (BIS) generated from RS (62, 32, 33). An ECC block unit includes 64K bytes of user data and 496 recording frames. Each recording frame includes: a sync pattern, 152 bytes of ECC data, and 3 bytes of BIS.

When modulating 8 bytes into 12 bytes according to the run-length limited (RLL) (1, 7) modulation method, if the number of sync patterns is 20, according to the slot length (CBL) in the track direction and the ECC format, it is The length occupied by the ECC block is 937,440×CBL.

The length of the ECC block disclosed in U.S. Patent No. 6,367,049 is equal to the circumference of a circle with a radius of 149,274×CBL. Since error correction corresponding to a length of 64 recording frames is possible according to the ECC format, the maximum error correction length is 120,960×CBL.

Therefore, when the CBL is 0.100 μm, the radius of a circle having a circumference equal to the length of the ECC block is 14.93 mm, and the maximum error correction length is about 12.10 mm.

When the CBL is 0.090 μm, the radius of a circle having a circumference equal to the length of the ECC block is 13.43 mm, and the maximum error correction length is about 10.89 mm.

When the CBL is 0.080 μm, the radius of a circle having a circumference equal to the length of the ECC block is 11.94 mm, and the maximum error correction length is about 9.68 mm.

When the CBL is 0.070 μm, the radius of a circle having a circumference equal to the length of the ECC block is 10.45 mm, and the maximum error correction length is about 8.47 mm.

When the CBL is 0.060 μm, the radius of a circle having a circumference equal to the length of the ECC block is 8.96 mm, and the maximum error correction length is about 7.26 mm.

In fact, an optical disc with a diameter of 120 mm has no overlapping area of these ECC blocks because recording starts at a radius exceeding 20 mm. However, for a small-sized optical disc having a diameter of 30 to 50 mm, the radius at which data is started to be recorded must be small to record as much data as possible.

In the case of applying the 64K-byte ECC format disclosed in U.S. Patent No. 6,367,049 to a small-sized optical disc in which data is recorded or stored from a radius of about 6 to 9 mm, and when the CBL is larger than 0.060 μm, the ECC Block units are inevitably recorded on two or more tracks.

If the CBL is 0.070 μm, and one recording frame includes 1890 slots, the length occupied by the recording frame is 132.3 μm. Therefore, a scratch of 2 mm can affect approximately 16 consecutive recorded frames. In this case, for the RS(248, 216, 33) code, an 8-byte error is caused, and when a scratch occurs on an overlapping area on which ECC block units are recorded to two tracks, 16 bytes will be caused. byte error.

Assuming that erasure correction is performed on the scratch area and the byte error rate is 10 ^-3 , the block error rate (BER) when an 8-byte error or a 16-byte error occurs in an ECC block unit is as shown in Table 1 .

Table 1

8 byte error 16 byte error BER when the scratch is 1mm 7.8×10^-20 2.5×10^-16 BER when the scratch is 2mm 2.5×10^-16 1.1×10^-9

Referring to Table 1, the BER when a scratch occurs on an area in which ECC block units overlap two tracks is larger than the error when a scratch of the same length occurs on an area in which ECC block units are in one track twice the BER.

The length L that the ECC block unit occupies the length of the recording medium in the track direction is a multiple of the slot number CBN of the ECC block, the minimum mark length MML according to the numerical aperture and laser wavelength, and the slot length CBL defined by the modulation code. That is, L=CBN×MML×CBL.

Under the same modulation code, by increasing the density of the recording line (reducing the minimum mark length), and by reducing the length of the slot, the length of the ECC block can be reduced, thereby minimizing or removing two or more overlapped ECC block units. Areas with many tracks.

However, the effect of errors causing problems such as scratches or fingerprints increases inversely proportional to the decrease in slot length. As a result, the effect of the error increases as the slot length decreases, even though the size of the error causing the problem does not change. That is, if the slot length decreases, the maximum error correction length of the ECC block also decreases. Therefore, reducing the length of the slots is accompanied by a problem of reducing the maximum error correction length of the ECC block as a way of recovering the error correction capability of the ECC blocks on the overlapping area.

Therefore, when reducing the size of the ECC block with a fixed slot length (minimum mark length equal to the modulation code) and with the same parity ratio, the maximum error correction length may also be reduced. The maximum error correction length under the structure of the ECC format proposed in U.S. Patent No. 6,367,049 is determined by adding the parity of codewords present in the ECC block unit and the interleaving depth between codewords. That is, since the ECC format is RS (248, 216, 33) code×304, the maximum error correction bytes are 9728.

As a result, since the reduction in the size of the ECC block that maintains the parity rate results in a reduction in interleaving depth or a reduction in the amount of user data, plus the parity of the codeword, the maximum error correction bytes will be reduced. Therefore, a decrease in error correction capability including the maximum error correction length will occur.

As described above, when the circumference of the area of the optical disc to which ECC blocks are recorded or stored is shorter than the length of the unit ECC block, the unit ECC block is recorded onto two or more tracks, thereby reducing the error correction capability , which leads to reduced reproduction reliability.

A conventional optical disc has a structure of a recording area in which a lead-in area, a user data area, and a lead-out area are sequentially formed from an inner peripheral area to an outer peripheral area. Generally, important information for reproducing data of an optical disc is recorded to an inner peripheral area corresponding to the lead-in area.

Therefore, a reduction in the error correction capability in units of ECC blocks recorded in the inner peripheral area becomes a serious problem.

Contents of the invention

technical solution

The present invention provides an error correction encoding method that prevents ECC block units from being recorded on two or more tracks of a small-sized optical disc and improves error correction capability.

The present invention also provides a device and method for recording data using the encoding method.

Beneficial effect

As described above, according to an embodiment of the present invention, an error correction encoding method, a method of recording data, and an apparatus for recording data can prevent ECC block units from being recorded to more than two tracks of a small-sized optical disc , so as to improve the error correction capability.

Furthermore, while increasing the parity rate by reducing the length of user data and maintaining the parity length of conventional Reed-Solomon encoding, conventional hardware can be used without major changes.

Description of drawings

These and/or other aspects and advantages of the present invention will become clearer and easier to understand through the following description of embodiments in conjunction with the accompanying drawings, wherein:

1 is a schematic diagram of an inner peripheral area of a small-sized optical disc to which data is recorded in conventional ECC block units;

Fig. 2 is the format of the LDC block according to the embodiment of the present invention;

Figure 3 is the format of an embodiment of the structure of the LDC block described in Figure 2;

FIG. 4 is a format of an LDC block after the LDC block described in FIG. 3 is interleaved in a predetermined method;

Fig. 5 is the format of the structure of the BIS block according to the embodiment of the present invention;

Figure 6 is the format of the BIS described in Figure 5 after interleaving;

FIG. 7 is a format of an ECC block produced by combining the LDC block described in FIG. 4 and the BIS block described in FIG. 6 with a synchronization pattern;

8 is a block diagram of an apparatus for recording and reproducing data according to an embodiment of the present invention; and

FIG. 9 is a flowchart illustrating a method of recording data according to an embodiment of the present invention.

best practice

Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the invention.

According to one aspect of the present invention, there is provided a method of error correction coding, comprising: generating (184, 152, 32, 216) LDC blocks with 32K bytes of user data; generating BIS blocks indicating the positions of error groups that occur; and generating an ECC block by combining a predetermined amount of BIS block data and an LDC block, wherein different portions of the BIS block are separated by a predetermined distance by one or more portions of the LDC block.

According to another aspect of the present invention, there is provided a data recording device, comprising: an optical head; a codec for generating a plurality of codewords by performing error correction encoding on a predetermined amount of data according to a predetermined method; and a control unit for controlling the optical head The data including the plurality of codewords is recorded in a recording unit whose length is shorter than a predetermined track in the inner circumference area of the small-sized optical disc.

The codec can perform error correction coding according to the Reed-Solomon coding method in which a parity byte P is added to the input data byte D, and can be used according to The error correction encoding is performed by supplementing the determined parity rate P/(D+P) which reduces the error correction capability caused by the short length of the recording unit.

The parity ratio can be determined by decreasing the input data byte D and increasing the parity byte P.

According to an embodiment of the present invention, there is provided a method for recording data to a small-sized optical disc, comprising: forming a plurality of codewords by performing error correction encoding on a predetermined amount of data according to a predetermined method; The data of the codeword is recorded to the small-sized optical disc in a recording unit whose length is shorter than a predetermined track of the inner peripheral area of the small-sized optical disc.

This error correction encoding can be performed according to a Reed-Solomon encoding method in which a parity byte P is added to an input data byte D.

The step of forming the plurality of codewords by error correction encoding may also include determining a parity check rate P/(D+P) for compensating for a decrease in error correction capability caused by the short length of the recording unit.

The step of forming multiple codewords by error correction encoding can increase the parity rate by reducing the input data bytes D and increasing the parity bytes P.

Embodiments of the present invention

Embodiments of the invention will now be described in detail, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like parts throughout. The embodiments are described below in order to explain the present invention by referring to the figures.

As described above, when data is recorded to a small-sized optical disc having a diameter of about 30 to 50 mm in which slots are located according to the ECC format having 64K bytes of user data disclosed in U.S. Patent No. 6,367,049, When the length (CBL) is between 0.060 μm and 0.133 μm and the initial radius of data recording is 6 mm˜9 mm, there is inevitably an overlapping area of ECC blocks in the radial direction.

In the present invention, the size of user data within an ECC block is reduced to 32K bytes to avoid overlapping of ECC blocks in the radial direction. In addition, the parity rate of the data is increased to compensate for the reduced error correction capability. The parity rate of data is expressed as the following equation.

Equation 1

Parity rate = P/(D+P)

In Equation 1, D represents the byte size of user data, and P represents the byte size of parity.

Considering the possible slot length (CBL) of 0.060 by current modulation codes and optical characteristics such as numerical aperture and laser wavelength, if the 64K byte ECC format disclosed in U.S. Patent No. 6,367,049 is modified to 32K byte ECC The format maintains the parity check rate of RS (248, 216, 33) code × 152 or RS (124, 108, 17) code × 304 in the same recording frame at the same time, then the ECC block with a size of 32K bytes has a radius of about 4.48mm is the same length as the circumference of a circle. Therefore, if the initial radius of the recorded data is 6-9mm, the ECC blocks will have no overlapping area in the radial direction, but the maximum error correction length is reduced to 3.63mm, thereby greatly reducing the error correction capability.

In order to prevent the reduction of the error correction ability, it is necessary to avoid overlapping of ECC blocks in the data recording area in the radial direction, and to extend the maximum error correction length, it is necessary to increase the data parity. However, a complete modification of the ECC format is not advisable.

FIG. 2 is a format of an LDC block according to an embodiment of the present invention. Referring to FIG. 2, N represents the length of the RS code, K represents the user data length of the RS code, P represents the parity length of the RS code, and C NUM represents the number of RS codes.

As mentioned above, in the case of (N, K, P, C_NUM) = (248, 216, 32, 152) or (N, K, P, C_NUM) = (124, 108, 16, 304), the 6th,367,049th C_NUM in the ECC format of U.S. Patent is halved, or N, K, and P are reduced to 32K bytes. In this case, when the CBL is 0.060μm, the maximum error correction length is only 3.63mm. Therefore, since it is likely that a reliability problem will occur in data reproduction, the data parity rate needs to be appropriately increased to improve error correction capability.

The ECC format of the present invention must satisfy the following conditions.

First, the size of an ECC block, which is a basic unit of recording and reproducing data, must be set to 32K bytes in this example to prevent ECC blocks from overlapping on two or more tracks in the radial direction. That is, since 4-byte error detection code (EDC) is added to each 2K byte (2048 byte) long sector, the number of bytes excluding parity in the LDC block is 32,832 bytes .

Second, BIS must be considered. The BIS must be large enough to store physical sector addresses and control data.

Third, the ECC format must have a maximum error correction length as long as possible.

Fourth, storage capacity in terms of data efficiency must be considered.

Fifth, when forming an ECC block, the total number of recording frames must be a multiple of 8 or 16. In the case of a DVD, an ECC block contains 16 physical sectors each having a data ID that allows quick access to the ECC block or physical sector when reproduced.

Sixth, considering the hardware load of the error correction system of the RS code, it is preferable that the number of parity checks of the RS code is less than 32, and the length of the RS code should be as long as possible.

Regarding the first condition, since the ECC format includes LDC and BIS, which is different from the RSPC structure of DVD, address information for accessing physical sectors has been stored in BIS as disclosed in U.S. Patent No. 6,367,049. Since data for controlling the user data can be stored in the control data, no additional data is necessary except for the user data and EDC.

Regarding the second condition, access to a physical sector or a space storing control information for user data is required.

Regarding the third and fourth conditions, when the maximum error correction length increases, the data efficiency decreases due to the low ratio of user data, thereby reducing the storage capacity of the entire medium. However, the storage capacity is more meaningful when the error correction capability of the ECC format exceeds a predetermined level. In other words, even though storage capacity may be large, it is of no use if the data is unreliable. After ensuring a sufficient level of error correction capability, the storage capacity of the medium can be meaningfully considered.

Regarding the fifth condition, although not necessarily, it is preferable that physical sectors are regularly arranged on the medium at appropriate intervals. Since the host and drive transmit and receive user data in a size of 2K bytes, and considering the fact that one block has a size of 32K bytes, the number of recording frames within one ECC block needs to be a multiple of 16.

Regarding the sixth condition, the hardware load of the RS coded error correction system is determined by the number of parities.

As the number of parity checks increases, the number of errors that can be corrected in a codeword increases. However, the load on the hardware also increases by the same order of magnitude. Considering conventional techniques, it is desirable to have less than 32 parities. As the codewords of the same parity rate become longer, the error correction capability increases.

FIG. 3 is a format of the structure of the LDC block described in FIG. 2 according to an embodiment of the present invention.

Referring to FIG. 3, the structure of the LDC block is (184, 152, 32, 216). That is, N is 184, K is 152, P is 32, and C_NUM is 216. Therefore, an error correction LDC block with a size of 32K bytes includes 216 (184, 152, 32) LDCs.

Typically, since the size of a data unit used to communicate between a host and a disk drive is 2K bytes per sector (2048 bytes), the ECC format adds 4 bytes of Error Detection Code (EDC) to the 2K bytes user data. A disk drive adds 4 bytes of EDC when encoding to check whether error correction has been completed after reading data from the disk and correcting errors. As shown in FIG. 3, 2052 bytes including 2K bytes of user data and 4 bytes of EDC correspond to 13.5 columns.

FIG. 4 is a format of an LDC block after the LDC block described in FIG. 3 is interleaved in a predetermined method.

There are several methods of interleaving. Figure 4 shows block interleaving according to the method described in Figures 10 and 12 of U.S. Patent No. 6,367,049. The first method of interleaving described in FIG. 10 of U.S. Patent No. 6,367,049 is a method of inserting byte information of odd columns between byte information of even columns. The second method of interleaving shown in FIG. 12 of U.S. Patent No. 6,367,049 is a method of shifting row information in the row direction after the first interleaving. In the above U.S. patent, the shift value is 3, but this embodiment could use a shift value of 1 or 7 that is relatively prime to 108, thereby maximizing the period.

FIG. 5 is a format of a structure of a BIS block according to an embodiment of the present invention. The BIS block has a structure of (46, K, P, C_NUM), which is summarized in Table 2 in this embodiment.

Table 2

K P C NUM physical address control data 14 32 16 16×9 bytes 16×5 bytes 14 32 twenty four 16×9 bytes 16×12 bytes twenty two twenty four 16 16×9 bytes 16×13 bytes twenty two twenty four twenty four 16×9 bytes 16×24 bytes

FIG. 6 is a format of BIS blocks of the first and third structures in Table 2 after interleaving according to the interleaving method described in FIG. 14A of U.S. Patent No. 6,367,049. In other words, since C_NUM is 16, C_NUM can be divided into 8 parts by bundling two codewords as shown in FIG. 5, and then interleaved according to the interleaving method described in FIG. 14A of U.S. Patent No. 6,367,049. Although not shown in the figure, the BIS blocks of the second and fourth structures are executed in the same manner as above except that the number of rows is changed to 3 in FIG. 6 .

FIG. 7 is a format of an ECC block created by combining the LDC block of FIG. 4 and the BIS block of FIG. 6 with a synchronization pattern.

Referring to FIG. 7, the ECC block includes 368 recording frames. Each recording frame includes: a sync pattern, a 108-byte LDC, and a 2-byte BIS. The ECC block includes 16 physical sectors, and 23 recording frames are recorded to each physical sector.

Each BIS byte includes an address of a physical sector, so that addresses of 16 physical sectors separated by a predetermined distance are recorded to a single ECC block.

When the C_NUM of the BIS block in Figure 5 is 24, then the number of rows in Figure 6 is 3 and each row of the ECC block in Figure 7 has a structure that is 4 LDCs of 27 bytes and 3 1s The byte BIS is inserted between the 27-byte LDC.

So far, the LDC block having the structure of (184, 152, 32, 216) described in FIG. 3 has been described. The structure of the LDC block according to the present invention may also include a structure such as (132, 108, 24, 304), (136, 108, 28, 304), or (140, 108, 32, 304).

When the structure of the LDC block is (132, 108, 24, 304), the structure has a BIS block of (33, 17, 16, 24) and can be formed in which 264 recording frames are recorded to 8 physical sectors ECC blocks.

When the structure of the LDC block is (136, 108, 28, 304), the structure has BIS blocks of (34, 18, 16, 24) and can be formed in which 272 recording frames are recorded to 8 physical sectors ECC blocks.

When the structure of the LDC block is (140, 108, 32, 304), the structure has a BIS block of (35, 19, 16, 24) and can be formed in which 280 recording frames are recorded to 8 physical sectors ECC blocks.

In a similar manner to the structure shown in Table 2, the (N, K, P, C_NUM) values of the BIS blocks in the above embodiments can also be modified to suit The structure of the recording frame in the block and the number of physical sectors of the predetermined size.

In the ECC block of Figure 7, if the modulation code modulates the RLL(1,7) level of 8 bits to 12 bits and the length of the sync pattern length is 20 bits, then ECC after a recording radius of 6mm when the CBL is less than 0.070μm Blocks do not overlap radially.

The maximum error correction length and data efficiency of different embodiments of the ECC block according to the present invention and the CBL of the conventional ECC block are summarized in Table 3.

table 3

Referring to Table 3, as shown in Figure 7, the first embodiment has (184, 152, 32, 216) LDC blocks and (46, 14, 32, 16) BIS blocks, and is in which 368 recording frames are Record to ECC blocks of 16 physical sectors. The second embodiment has an LDC block of (132, 108, 24, 304) and a BIS block of (33, 17, 16, 24), and is an ECC block in which 264 recording frames are recorded to 8 physical sectors . The third embodiment has an LDC block of (136, 108, 28, 304) and a BIS block of (34, 18, 16, 24), and is an ECC block in which 272 recording frames are recorded to 8 physical sectors . The fourth embodiment has an LDC block of (140, 108, 32, 304) and a BIS block of (35, 19, 16, 24), and is an ECC block in which 280 recording frames are recorded to 8 physical sectors . Conventional technology refers to the ECC block of U.S. Patent No. 6,367,049.

The block error rate according to the conventional technique and the block error rate (BER) according to the present invention are shown in Table 4 to Table 6 assuming that erasure correction is performed on a portion where a scratch occurs. BER is calculated according to Equation 2 and Equation 3 below.

Equation 2

$\mathrm{<span\; class="notranslate">\; CER</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\overset{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; parity</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; e</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; Q</span>}}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; -</span>\underset{\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; e</span>}}<span\; class="notranslate">\; )</span>{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; P</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; e</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; P</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}$

Equation 3

$\mathrm{<span\; class="notranslate">\; BER</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; CER</span>}<span\; class="notranslate">\; )</span>}^{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Kid</span>}}}$

Among them, CER represents the code word error rate, e represents the number of erasures, and p represents the byte error rate.

Table 4

Example 1 Example 2 Example 3 Traditional technology parity check 32 twenty four 28 32 p 0.001 0.001 0.001 0.001 e 14 10 10 10 N 184 132 136 248 C_NUM 216 304 304 304 BER 7.9×10^-13 2.6×10^-10 5.3×10^-14 1.3×10^-14

Table 4 shows the BER when a scratch of 2.268 mm occurred in each case.

table 5

Example 1 Example 2 Example 3 Traditional technology parity check 32 twenty four 28 32

p 0.001 0.001 0.001 0.001 e 7 5 5 5 N 184 132 136 248 C_NUM 216 304 304 304 BER 3.2×10^-18 5.7×10^-14 8.6×10^-18 4.8×10^-18

Table 5 shows the BER when a scratch of 1.134 mm occurred in each case.

Table 6

Example 1 Example 2 Example 3 Traditional technology parity check 32 twenty four 28 32 p 0.001 0.001 0.001 0.001 e 0 0 0 0 N 184 132 136 248 C_NUM 216 304 304 304 BER 1.3×10^-9 3.2×10^-7 3.4×10^-9 2.8×10^-7

Table 6 shows the BER when there is no scratch in each case.

The first to third embodiments and the conventional technology in Table 4 to Table 6 indicate the first to third embodiments and the conventional technology in Table 3, respectively.

When compared with the conventional technology, the data efficiency and error correction capability of the first and third embodiments are optimal in the case of a CBL of 0.06 μm.

Hereinafter, a data recording and/or reproducing device according to the present invention will be described.

FIG. 8 is a block diagram 200 of an apparatus for recording and reproducing data according to an embodiment of the present invention.

Referring to FIG. 8, the apparatus 200 for recording and/or reproducing data includes: an optical head 210, a codec 220, an optical disc information storage unit 240, a control unit 260, a data input interface unit 270, and a user interface unit 280.

The optical head 210 records data to the small-sized optical disc 100 or reads data recorded on the small-sized optical disc 100 in response to the control of the control unit 260 . The small-sized optical disc 100 is an optical disc having a radius of the innermost circumference of 6 mm.

The codec 220 performs error correction encoding on data to be recorded to the small-size optical disc 100 according to an embodiment of the present invention, or decodes data read from the small-size optical disc 100 in an inverse process of encoding.

The disc information storage unit 240 stores information related to the small-sized optical disc 100 .

The codec 220 generates an LDC block by encoding user data according to various ECC formats as shown in the first to fourth embodiments of the present invention. The codec 220 calculates parity according to a predetermined method. The method of calculating the parity may be a conventional method, and thus a detailed description thereof will be omitted.

Also, the codec 200 generates a BIS block to indicate the position of an error when reproducing data, and generates an ECC block by arranging the LDC data and the BIS data at a predetermined distance as described in FIG. 7 . The codec 220 finally generates an ECC block to be recorded to the small-sized optical disc 100 and outputs to the optical head 210 .

The disc information storage unit 240 stores information on the small-sized optical disc 100 . This information includes the data area structure of the small-sized optical disc 100 or the data recording algorithm.

The control unit 260 controls the codec 220 and the optical head 210 to record data to the small-sized optical disc 100 . Specifically, the control unit 260 controls the optical head 210 to record the data output from the codec 220 to the small-sized optical disc 100 in a recording unit shorter than the length of a predetermined track of the inner peripheral area of the small-sized optical disc 100 .

The input data interface unit 270 transmits input data to be recorded to the small-sized optical disc 100 to the control unit 260 .

The user interface unit 280 transmits a command input from a user for recording data to the small-sized optical disc 100 to the control unit 260 .

Referring to the structure of the data recording/reproducing apparatus 200 as described above, a method of recording data to the small-sized optical disc 100 according to an embodiment of the present invention will now be described.

FIG. 9 is a flowchart of a method of recording data according to an embodiment of the present invention.

In order to record data to the small-sized optical disc 100, the size of the ECC block is reduced. However, in order to compensate for the decrease in error correction capability due to the decrease in the ECC block size, a parity rate of Reed-Solomon encoding for error correction is determined (operation 410). By employing an LDC block having a structure of (184, 152, 32, 216), the parity rate in the embodiment of the present invention is improved to 32/184. Information necessary for error correction including a determined parity rate is recorded in the codec 220 in advance.

The codec 220 generates a plurality of codewords by error-correcting encoding a predetermined amount of input data, such as 32K bytes of user data, according to the determined parity rate of the Solomon encoding (operation 430).

Even though not described in the flowchart, the codec 220 generates a BIS block to indicate the position of an error when reproducing data, and generates an ECC block by arranging LDC data and BIS data at a predetermined distance as described in FIG. 7 . The codec 220 finally outputs the ECC blocks to be recorded to the small-sized optical disc 100 to the optical head 210 .

On the other hand, various ECC formats other than the LDC block of (184, 152, 32, 216) can be formed as in the second to fourth embodiments of the present invention.

The optical head 210 receives data including a plurality of codewords from the codec 220 in response to the control of the control unit 260, and stores the data in a recording unit having a length shorter than the length of a predetermined track of the inner peripheral area of the small-sized optical disc 100. Record to the small-sized optical disc 100 .

The present invention can also be embodied as computer readable codes on a computer readable recording medium. The computer readable recording medium is any data storage device that can store data which can be thereafter read by a computer system. Examples of the computer readable recording medium include read only memory (ROM), random access memory (RAM), CD-ROM, magnetic tape, floppy disk, optical data storage devices, and carrier waves. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

While certain embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that such implementations may be made without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents. Example changes.

Claims (8)

1. method for recording data, this method comprises:

Form a plurality of code words by the data of scheduled volume being carried out Error Correction of Coding according to predetermined method; With

The data that will comprise described a plurality of code words record the small size CD with such record unit, and the length of this record unit is shorter than the planned orbit of the inner circumference area of small size CD.

2. the method for claim 1, wherein described Error Correction of Coding is performed according to the Reed Solomon Coding method, and parity byte P is added to Input Data word joint D in the Reed Solomon Coding method.

3. method as claimed in claim 2, wherein, the step that forms a plurality of code words by Error Correction of Coding also comprises the parity checking rate P/ (D+P) of the reduction that is identified for replenishing the error correcting capability that the length by the record unit causes.

4. method as claimed in claim 3, wherein, the step that forms a plurality of code words by Error Correction of Coding improves the parity checking rate by reducing Input Data word joint D and increasing parity byte P.

5. data recording equipment comprises:

Shaven head;

Coding decoder produces a plurality of code words by according to predetermined method the input data of scheduled volume being carried out Error Correction of Coding; With

Control module, the control shaven head writes down the data that comprise described a plurality of code words with such record unit, and the length of this record unit is shorter than the planned orbit in the inner circumference area of small size CD.

6. data recording equipment as claimed in claim 5, wherein, described coding decoder is carried out Error Correction of Coding according to the Reed Solomon Coding method, and parity byte P is added to Input Data word joint D in the Reed Solomon Coding method.

7. data recording equipment as claimed in claim 6, wherein, described coding decoder is carried out Error Correction of Coding according to the parity checking rate P/ (D+P) that determines, described parity checking rate P/ (D+P) is used for replenishing the reduction of the error correcting capability that is caused by the length that writes down unit.

8. data recording equipment as claimed in claim 7, wherein, described parity checking rate is determined by reducing Input Data word joint D and increasing parity byte P.

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