JPH11259868A - Optical disk and optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rewritable optical disk which can make format efficiency higher and record data at an arbitrary position without any waste and further, obtain address information in sector units without solving error correction and an optical disk device for driving the optical disk. SOLUTION: This optical disk 10 on which data are recorded and reproduced in the units of error correction blocks consisting of plural sectors by using a light beam is provided with land tracks 13 and groove tracks 14 which are arranged adjacently to each other and recognition marks e.g. embossed pits 16 which are formed on the border of the land track and the groove track and used to recognize the position of the error correction block.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk capable of recording and reproducing data and an optical disk drive for driving the optical disk.

[0002]

2. Description of the Related Art In a rewritable optical disk capable of repeatedly recording data at an arbitrary position on a disk and reproducing data at an arbitrary position, data is generally recorded in sector units. In this case, sector address information and error-correction-encoded data are recorded in each sector.

On the other hand, a recently standardized 120 mm
A large-capacity rewritable optical disc called a DVD-RAM having a large diameter requires an error correction data obtained by performing error correction coding over a plurality of sectors instead of a sector unit in order to improve the error correction capability of the data. Data can be recorded in units of correction blocks (ECC blocks).
The same applies to a DVD-ROM which is a read-only optical disk, in which data is recorded in units of error correction blocks consisting of 16 sectors including 2048 bytes of data per sector. In the DVD-ROM, the error correction coding is applied to the address information of the error correction block and the sector in the same manner as the data, so that the structure is extremely resistant to errors.

In a DVD-RAM, address information in sector units is recorded in advance as emboss pits on a disk, and one error correction block is generated in a plurality of sectors (16 sectors) when data is recorded. In this way, address information is always obtained in sector units,
For example, even if the optical head is erroneously moved to an adjacent track during recording, there is an advantage that the damage of the erroneous recording is only one sector and the seek time is reduced. Further, since a periodic signal corresponding to the cycle of the sector can always be obtained from the address information of the sector during recording and reproduction, it is possible to control the spindle motor for rotating the optical disk according to the periodic signal.

[0005]

By the way, the conventional DV
In a method of recording address information on a sector basis, such as a D-RAM, in addition to an address information area (header field) in each sector, a disk rotation speed fluctuation or eccentricity at the time of data recording / reproduction causes a disk eccentricity. For recording original data, such as a buffer area for responding to the actual change in the sector length above, and a buffer area for responding to random shift of the recording position and start / end deterioration when using the phase change recording method. The area other than the above area increases, and this causes the format efficiency to decrease. For this reason, in order to secure a sufficient recording capacity, it is necessary to increase the recording density by that much, and if the recording density is kept constant, there is a problem that the recording capacity is reduced by that much.

On the other hand, as a method for recording data without forming address information in sector units on an optical disc,
For example, as employed in CD-R, CD-RW, etc., a method of wobbling a groove on an optical disk to record address information as an FM signal, and recording data in error correction block units based on this. There is. In this case, since the address of the error correction block is determined only after data is recorded, it is generally difficult to record data at an arbitrary position without waste.

Further, since the address information of the error correction block and the address information of the sector cannot be taken out without solving the error correction, even if the address is deviated during recording, it cannot be dealt with. Data may be recorded. Furthermore, even when seeking to another track, the address information must be corrected for errors, and the time required to find the target address becomes longer, so that there is a drawback that the data read / write wait time becomes longer. Also, the groove wobble (wobbl)
The address information recorded in the form of e) is degraded during many times of writing.

Further, in an area where data is written, a periodic signal having a sector cycle necessary for controlling the spindle motor is obtained from the optical disk. In an area where data is not written, such a periodic signal is generated. I can't get it. For this reason, after data is written, finalization for recording a dummy signal for generating a periodic signal on a plurality of tracks is required, and extra recording time is required.

As described above, among the conventional rewritable optical disks, in an optical disk in which address information in sector units is recorded as pre-pits, the actual sector caused by fluctuations in the rotational speed of the disk, eccentricity, and the like for each sector. Since it is necessary to provide a buffer area to cope with a change in length or a random shift of the recording position when using the phase change recording method and deterioration of the start and end, an area other than an area for recording the original data is required. Increased format efficiency.

On an optical disk on which address information is recorded by wobbling a groove and data is recorded in units of error correction blocks, it is not only difficult to record data at an arbitrary position without waste, but also to release error correction. Address information cannot be obtained in sector units without
Further, there is a problem that a finalization process for generating a periodic signal for controlling the spindle motor is required, and it takes a long time for recording.

SUMMARY OF THE INVENTION It is an object of the present invention to improve the format efficiency, to record data at an arbitrary position without waste, and to obtain address information in sector units without error correction. It is an object of the present invention to provide a rewritable optical disk and an optical disk device for driving the optical disk.

It is another object of the present invention to provide an optical disk and an optical disk apparatus which can control the rotation by using a signal obtained from the optical disk without requiring any extra finalization processing.

[0013]

SUMMARY OF THE INVENTION The present invention relates to an optical disk in which data is recorded and reproduced in units of an error correction block composed of a plurality of sectors by using a light beam. And an optical disc having a groove track and a plurality of recognition marks formed on a boundary between a land track and a groove track for recognizing a position of an error correction block.

The present invention is directed to an optical disk apparatus that records and reproduces data in units of error correction blocks composed of a plurality of sectors by irradiating a light beam onto a rotationally driven optical disk. Detecting the recognition mark of the optical disc comprising a land track, a groove track, and a plurality of recognition marks formed on a boundary between the land track and the groove track to recognize a position of the error correction block. An optical disk device, comprising: means for writing address information of the sector constituting the error correction block based on information from the detected recognition mark.

As described above, the recognition information of the error correction block is recorded as a recognition mark such as an emboss pit on the optical disk, and based on the recognition information, the data of each sector of the error correction block and the address information of the sector are written. When recording is performed, the actual sector length changes on the disk due to fluctuations in the rotational speed and eccentricity of the disk during data recording and reproduction, and random shift and start / end of the recording position when using the phase change recording method The buffer area for dealing with the degradation may be provided for each error correction block. In other words, the buffer area is smaller than that of a conventional optical disc that records address information in sector units as embossed pits, so that the area for recording original data can be increased by that amount, and the format efficiency is improved. I do.

Further, since the position of the error correction block is predetermined on the optical disk, it is possible to write data to an arbitrary error correction block when recording data. Moreover, the data in the error correction block is subjected to the error correction coding, while the address information of the sector is not subjected to the error correction coding. Therefore, the sector address is decoded in real time without decoding the error correction block. Can be recognized, and it is possible to immediately cope with an address deviating during recording.

Further, the optical disk device according to the present invention comprises:
Land tracks and groove tracks on the optical disk are wobbled with a wobble pattern having a fixed period,
A periodic signal corresponding to the wobble pattern is generated from the output of the photodetector that detects the reflected light from the optical disk, and the rotation of the optical disk is controlled based on the periodic signal.

With this arrangement, a periodic signal necessary for controlling the spindle motor can be always obtained regardless of whether data is written on the optical disk at the time of reproduction. And the time required for recording is reduced.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

First, an optical disc according to an embodiment of the present invention will be described. FIG. 1 is an enlarged view of a part of the optical disk, FIG. 2 shows a track pattern on the optical disk,
FIG. 3 shows an enlarged part of FIG. FIG. 4 shows a spiral format on an optical disk.

As shown in FIG. 1, the optical disk 10 of the present embodiment is formed by forming a recordable / reproducible recording film 12, for example, a phase change film on a disk substrate 11. Land tracks 13 and groove tracks 14 are formed in a spiral shape on the disk substrate 11 as shown in FIGS. Land track 13 and groove track 14
There are two types of arrangement methods, a single spiral format shown in FIG. 4A and a double spiral format shown in FIG. 4B. Single spiral format uses land track 13 on one spiral.
The double spiral format is a method in which land tracks 13 and groove tracks 14 are respectively arranged on two parallel spirals. In both cases, land and groove tracks 14 are arranged along the radial direction of the disk. The grooves are arranged alternately adjacent to each other.
The present invention can be applied to any of these systems.

In this embodiment, as shown in FIGS. 2 and 3, the land track 13 and the groove track 14 are wobbled by a wobble pattern having a constant period. FIGS. 1 and 4 show diagrams without wobbling for simplicity.

As shown in FIGS. 1, 2 and 3,
The groove track 14 is divided on the way, and the divided area is a land portion 15. An emboss pit 16 is formed on the boundary between the land 15 and the land track 13 in the divided area. Here, the emboss pits are formed together with the land / groove tracks by a masking process when forming the disk.

The emboss pit 16 is for giving information for recognizing the position of an error correction block (hereinafter, referred to as an ECC block) in land tracks and groove tracks located on both sides thereof. It represents a boundary and is formed with a period substantially equal to the ECC block length. Further, the emboss pit 16 is composed of a set of a plurality of, preferably three or more pits. Each emboss pit may have the same pit pattern as long as it is used only for simply recognizing the position of the ECC block. Although a circular pit is shown in the figure, the shape of the pit is not limited to this, and may be an ellipse, an ellipse, or a combination thereof.

Since the emboss pit 16 may be provided for recognizing the ECC block, the emboss pit 1 can be provided without providing the division area 15 in the groove track 14.
6 may be provided. Also, instead of embossed pits, marks of other forms (for example, phase change marks) may be formed. That is, pits or marks may be formed in the land track 13 in a semicircular form, and these pits or marks may be used as ECC block recognition information.

As described above, by forming the emboss pit 16 indicating the recognition information of the ECC block for each ECC block, the format efficiency can be increased as will be described later in detail.

FIG. 3 shows specific numerical examples of the land tracks 13, groove tracks 14, emboss pits 16 and light beam spots 17a and 17b on the optical disk 10. This is the current DVD-RA
This is an example of a rewritable optical disk in which M has been further densified.
The track pitch (center line interval between the land track 13 and the groove track 14) is 0.55 μm, and the width of the emboss pit 16 is 0.35 μm. Further, the wavelength λ of the light beam is 650 nm, and the NA of the objective lens is 0.6.
And the light beam spot diameter is φ0.93 μm.

The signal from the emboss pit 16 is detected when the light beam spot 17a is tracing on the land track 13. In this case, the light beam spot 17a corresponds to the land track 13
Since a part of the groove track 14 adjacent to the groove track 14 is also traced, it is necessary to consider the influence from a recording mark such as a phase change mark formed on the groove track 14.

Here, the width of the light beam spot 17a on the groove track 14 is one of the light beam spot diameter.
1/2 of the track pitch from 0.465 μm
0.175 μm obtained by subtracting 0.275 μm, which is a distance of 0.4 μm from the light beam spot 17 a to the groove track 14 adjacent to the land track 13.
m. On the other hand, the width of the emboss pit 16, that is, the dimension in the track width direction is 0.35 μm, and the emboss pit 16 is arranged at a position such that the entire width falls within the light beam spot 17a.

Therefore, considering the size relationship between the size of the portion of the light beam spot 17a on the emboss pit 16 and the size of the portion on the groove track 14, the recording mark formed on the groove track 14 by the light beam spot 17a. It can be seen that the emboss pits 16 can be reliably detected without being greatly affected by the noise.

Further, when the light beam spot 17b traces on the groove track 14, it is necessary to consider the effect of the emboss pit 16 when detecting a recording mark formed on the groove track 14.

Since the emboss pit 16 is formed on the boundary between the land 15 and the land track 13 in the divided area of the groove track 14, the distance between the light beam spot 17b and the emboss pit 16 is equal to the track pitch. 0.185 μm obtained by subtracting 0.465 μm which is 1/2 of the light beam spot diameter and 0.175 μm which is 1 / 2n of the width of the embossed pit 16 from 0.825 μm which is 1.5 times as large as the above. You can see that it is far enough. Therefore, it can be seen that the recording mark formed on the groove track 14 can be reliably detected without being affected by the emboss pits 16.

The emboss pits 16 are provided on the boundaries between the land portions 15 that divide the groove tracks 14 and the land tracks 13 that are adjacent either inside or outside in the disk radial direction. Thereby, the recognition information of the ECC block given by the emboss pit 16 is shared by both the land track 19 and the groove track 13 located on both sides thereof.

As described above, the optical disk 10 is replaced with the current DVD.
-Even if the track pitch is narrowed to achieve a higher density than that of the RAM and the light beam spot size is further narrowed to cope with this, the adjacent groove tracks 14
The signal from the embossed pit 16 can be detected with a sufficient SNR without being affected by the upper recording mark,
Moreover, it is possible to reliably detect a signal from a recording mark on the groove track 14 adjacent to the position where the emboss mark 16 is formed without being affected by the emboss pit 16.

Next, an optical disk apparatus for recording and reproducing data by driving the optical disk 10 described above with reference to FIGS. 5 and 6 will be described.

In FIG. 5, the optical disk 10 is rotated by a spindle motor 21 driven by a motor driver 20, and recording / reproducing on / from the optical disk 10 is performed by an optical head 22 provided opposite to the optical disk 10. The optical head 22 includes, but is not limited to, a laser diode (LD) 23 as a light source,
A collimator lens 24 for converting a light beam emitted from the laser diode 23 into parallel light, a beam splitter 25 for separating light incident on the optical disk 10 and light reflected from the optical disk 10, and a beam splitter 2.
An objective lens 26 for condensing the light beam that has passed through 5 and irradiating the light beam onto the optical disc 10 as a minute light beam spot, and a condensing element for condensing the reflected light reflected by the optical disc 10 and guided by the beam splitter 25 Optical lens 27
And a photodetector 28 for detecting the condensed reflected light, and a lens actuator 29 for moving the objective lens 26 in the optical axis direction (focus direction) and the tracking direction.

The photodetector 28 has a plurality of detection areas, for example, four detection areas.
A multi-segment detector divided into two regions is used. The plurality of output signals output from the photodetector 28 are input to the analog operation circuit 34. The analog operation circuit 33
A reproduction signal corresponding to data recorded on the optical disk 10, a focus error signal and a tracking error signal for focus servo and tracking servo, and a speed control signal for controlling a rotation speed of the spindle motor 21 are generated. The focus servo is a control for making the focus of the objective lens 26 coincide with the recording surface on the optical disk 10, and the tracking servo is a control for the optical disk 1.
This is control for causing the light beam irradiated on the zero to follow the track.

The focus error signal and the tracking error signal are input to the servo circuit 30, and the objective lens 26 is controlled in the focus direction and the tracking direction by the lens actuator 29 under the control of the servo circuit 30. Further, the servo circuit 30 controls the motor driver 20 according to a speed control signal generated based on a later-described periodic signal obtained from the optical disc 10.

Next, an outline of the recording operation and the reproducing operation will be described.

Recording Operation At the time of recording, a recording data sequence D which is data to be recorded is recorded.
After “in” is processed by the recording data processing unit 31, it is input to the LD driver 32, and the LD driver 32 modulates the intensity of the laser diode 23. The light beam thus intensity-modulated is irradiated onto the optical disk 10 via the collimator lens 24, the beam splitter 25, and the objective lens 26, so that data is recorded on the recording film 12 of the optical disk 10, for example, from a crystalline mark to an amorphous mark. , Or as a phase change mark from amorphous to crystalline.

Here, at the time of recording, the reflected light from the optical disk 10 enters the photodetector 28 via the objective lens 26, the beam splitter 25 and the condenser lens 27.
The output of the photodetector 28 is input to the analog arithmetic circuit 33, and the signal corresponding to the emboss pit 16 on the optical disk 10 (hereinafter referred to as emboss pit signal) and the wobble pattern of the land track and the groove track on the optical disk 10 As a result, a periodic signal whose amplitude changes is generated.

The timing generation circuit 34 generates an ECC corresponding to the emboss pit 16 according to the emboss pit signal.
Generate block recognition information and generate a speed control signal according to the periodic signal. The recognition information of the ECC block is used by the recording data processing unit 31 to generate an ECC block and further to generate sector address information. The details of this processing will be described later in detail. The speed control signal is input to the servo circuit 30, and the servo circuit 30 controls the spindle motor 21 to a predetermined rotation speed via the motor driver 20 based on the speed control signal.

At the time of recording, a focus error signal and a tracking error signal are further generated by the analog arithmetic circuit 33, and the lens actuator 29 is controlled by the servo circuit 30 based on these signals. Tracking servo is performed.

Reproduction Operation During reproduction, a light beam having a constant intensity emitted from the laser diode 23 is irradiated onto the optical disk 10 via the collimator lens 24, the beam splitter 25 and the objective lens 26. The reflected light from the optical disk 10 enters the photodetector 28 via the objective lens 26, the beam splitter 25, and the condenser lens 27. The output of the photodetector 28 is input to an analog arithmetic circuit 33, and a change in reflectance depending on the presence or absence of a recording mark on the recording film 12 is output as a reproduction signal.

At the time of this reproduction, the analog arithmetic circuit 33 generates a periodic signal corresponding to the wobble pattern on the optical disk 10, a focus error signal and a tracking error signal. A timing control circuit generates a speed control signal in accordance with the periodic signal, and the servo circuit 30 controls the spindle motor 21 to a predetermined rotation speed via the motor driver 20 based on the speed control signal. Further, the lens actuator 29 is controlled by the servo circuit 30 based on the focus error signal and the tracking error signal, so that focus servo and tracking servo are performed.

The reproduction signal corresponding to the recording mark output from the analog operation circuit 33 is converted into binary data by the binarization circuit 35 and then input to the timing generation circuit 34. The timing generation circuit 34 detects a synchronization pattern in the reproduction signal from the binary data, specifically, detects the position and pattern of the synchronization pattern. Since the reproduction signal includes a bit error generated due to a medium defect of the optical disc 10 or the influence of noise, the synchronization signal cannot be detected at a position where the synchronization pattern should be detected in the timing generation circuit 34 or differs from the original synchronization pattern. A synchronization pattern may be erroneously detected at a position. The timing generation circuit 34 considers these effects,
It has a function of correctly detecting the position of the synchronization pattern, and in addition to the detection position signal of the synchronization pattern, combines a synchronization pattern detection signal indicating which of the synchronization pattern sequences SY0 to SY7 described below is present. The boundary of each of the demodulated symbol, the recording block, and the recording sector after the modulation is determined using the above.

The output of the binarization circuit 35 is input to the reproduction data processing section 36. The reproduction data processing unit 36 includes a demodulation circuit 361, a memory 362, a memory controller 363 for controlling the memory, and an error correction decoding processing unit 366, as shown in FIG. The reproduction data sequence Dout is output by performing a process substantially opposite to that of the recording data processing unit 31.

Next, the recording data processing section 31 will be described in detail. FIG. 7 shows a processing procedure of the recording data processing unit 31.

First, the recording data sequence Din is input from, for example, a host system (not shown) (step S10).
1).

Next, a data frame is generated from the recording data sequence Din input in step S101 (step S102). In the data frame generation step S102, the recording data sequence Din is divided into data sectors in units of 2048 bytes, and 178 × 1
Generate a 2-byte data frame.

FIG. 8 shows the structure of a data frame. As shown in the figure, the data frame is composed of 2064 bytes arranged in a 12-row array with 172 bytes as one row. The first line is 4-byte data identification data (data ID) and a 2-byte ID error detection code (IED) for detecting an error occurring in the data ID.
And 6 bytes of spare bytes (RSV) and 160 bytes of main data D _{0 to} D ₁₅₉ . Main data is an element of a data sector. The second to eleventh lines are 172 bytes of main data D _{160 to} D ₁₆₀ respectively.
₃₃₁ , D _{332 to} D ₅₀₃ ,..., D _{1708 to} D
_The last twelfth line is composed of 168 bytes of main data D _{1880 to} D ₂₀₄₇ and a 4-byte error detection code (EDC) for detecting an error occurring in a data frame.

Hereinafter, the data ID will be described in more detail. As shown in FIG. 9A, the data IDs are sequentially numbered with the least significant bit being b0 and the most significant bit being b31. The meaning of each bit of the data field information consisting of the most significant 1 byte is as shown in FIG. 9B, and is set as follows. Bit b31 (sector format type): set to "1" to indicate a zoned format. Bit b30 (tracking method): Set to "0" indicating pit tracking in an embossed portion in the lead-in zone, and set to "1" indicating groove tracking in other areas. Bit b29 (reflectance of recording film): set to "1",
Indicates that the reflectance is 40% or less. Bit b28 (spare): set to "0" Bits b27 and b26 (zone type): set to "00" in the data zone, "01" in the lead-in zone, and "10" in the lead-out zone. Bit b25 (data type): set to "0" when the data in the data sector is read-only data, and set to "1" when the data is rewritable data.

Bit b24 (layer number): Set to "0", indicating that only one recording film can be accessed from one incident surface.

On the other hand, the data field number consisting of the lower 3 bytes of bits b23 to b0 indicates the sector number in the embossed portion in the lead-in zone, the defect management area, and the spare zone in binary notation. Indicates the data field number after re-initialization, and indicates the sector number in binary in the defect management area and the spare zone in the lead-out zone.

After the data frame is generated in step S102, a scrambling process is performed (step S103).
In this scrambling process, the main data D _k (k = 0 to 2047) in the data frame is replaced with D _k ′ (k = 0 to 2047) scrambled by the following equation.

D _k ′ = D _k XOR S _k , k = 0 to 2047 Here, XOR represents an exclusive OR.

S _k is a random data sequence for scramble processing, for example, an M sequence, and is generated by the following procedure. That is, a 15-bit shift register is prepared, the most significant bit and the output of the fifth bit from the most significant bit are exclusive ORed, and the result is connected to the input of the least significant bit. A register is configured. As the scramble data, the lower 8-bit output of the feedback shift register is used. Each time the scrambled data is taken out, the feedback shift register is shifted upward eight times to take out the next scrambled data.

The scramble process can be performed by taking the exclusive OR of the scramble data generated by the above procedure and the main data for each bit. In this case, the generated scramble data sequence can be switched by changing the initial value of the feedback shift register. The switching of the initial value is performed according to the content of the data ID in the data field.

The ECC block is generated by performing error correction coding on the data frame (referred to as a scrambled frame) after the scramble processing in step S103 (step S104).

FIG. 10 shows the structure of an ECC block.
The ECC block includes a scrambled frame in each row 17.
By arranging 192 rows as 2 bytes, and adding 16 bytes as outer code parity PO to each 172 columns, 208 rows are obtained, and adding 10 bytes as inner code parity PI to each of these rows, 182 bytes in each row The ECC block is composed of 208 rows consisting of Each byte is as follows when i is the number of rows and j is the number of columns and B _{i, j} is set.

B _{i, j} for i = 0-191 and j = 0-171: bytes from the scrambled frame. B for i = 192-207, j = 0-171.
_{i, j} : byte of outer code parity B for i = 0 to 207, j = 172 to 181
_{i, j} : Byte of inner code parity To further explain the generation procedure of the ECC block described above, 16 scrambled frames consisting of 12 rows are stacked, and a set of 16 scrambled frames is used as a data unit for error correction coding. Is performed, error correction coding is performed, a check parity is added, and an ECC block is generated. Here, the error correction code is a Reed-Solomon code 2
Use multiply sign.

That is, encoding (outer encoding) is performed on 192 rows of data of 16 stacked scrambled frames, and an outer code parity P of 16 bytes is obtained.
O is generated. The outer code is (208, 192, 17)
RS code. The same outer coding is repeated for all the columns (172 columns) of the 16 scrambled frames stacked. Next, 172 bytes of data in each row of the 16 scrambled frames of the stack are encoded (inner encoding) to generate an inner code parity PI of 10 bytes. The inner code is (182, 172, 1
1) It is an RS code. Similar inner coding is repeated for all the rows of the 16 scrambled frames stacked, that is, 208 rows including the outer code parity PO.

A recording frame is generated by interleaving one of the 16 outer code parities PO for every 12 rows of the ECC block shown in FIG. 10 generated in step S104. Specifically, the recording frame is generated by rearranging the bytes B _{i, j} of the ECC block as B _{m, n with} respect to the following equation. m = i + int [i / 12] and n = j, i ≦ 191 m = 13 (i−191) −1 and n = j, i ≧ 192 where int [x] represents an integer equal to or less than x.

As a result, 37856 bytes of the ECC block are 16 bytes of 2366 bytes as shown in FIG.
Are rearranged into recording frames. Each recording frame is
Each row forms an array of 13 rows of 182 bytes.

The data of the recording frame generated in step S105 is recorded on the optical disc 10
Then, data conversion in accordance with the signal transmission characteristics of the optical head 22, that is, modulation processing is performed (step S106).
In order to reduce the recording density (linear density) on the optical disk 10 as much as possible, it is desirable that the maximum frequency of the recording signal is low, and from the viewpoint of signal transmission, the recording signal desirably has a low frequency component. In consideration of these two requirements, step S1
As a modulation method in 06, a method in which frequency components are generally concentrated in the middle band is used. As the modulation method, in the present embodiment, for example, a continuous length of “0” is “2” for 8-bit data,
RLL in which the continuous length of "1" is limited to "10" respectively
8/16 modulation is used to convert to a 16-bit codeword consisting of (2,10) codes. This 16-bit codeword is NRZ-I converted into channel bits. The channel bit is an element that expresses binary “1” and “0” after modulation by pits or marks on the optical disc 10.

A data field for recording on the optical disk 10 is generated from the modulated recording frame obtained in step S106. When reproducing data recorded on the optical disk 10, the original data cannot be reconstructed unless boundaries between recording frames can be determined. Therefore,
In step S107, as shown in FIG. 11, a 32-bit synchronization pattern is added to the beginning of 1456 channel bits of each recording frame after the modulation processing to generate a 1488-bit-length synchronization frame, thereby forming a data field. . This data field is composed of 13 rows, each row consisting of two synchronization frames.
The 456 channel bits represent the first and second 91 eight-bit bytes of each one row of the recording frame.
Each row of the data field represents each row of the recording frame.

As the synchronization pattern, it is desirable to select a pattern that can be easily detected from the recorded data sequence and that is not erroneously detected. In FIG. 12, eight types of synchronization patterns SY0 to SY7 are prepared as synchronization pattern sequences used as synchronization patterns. These synchronization pattern sequences SY0
~ SY7, one synchronization pattern is selected according to the position of the recording frame in the data field after the modulation processing.

Finally, an ECC block recording format is generated from the data field generated in step S107. According to the generated recording format, LD
The intensity of the light beam emitted from the laser diode 23 is modulated by the driver 32, thereby recording on the optical disk 10 as described above. The recording format of the ECC block will be described later in detail.

Next, the reproduction data processing section 36 shown in FIG. 6 will be described.

First, the demodulation circuit 361 includes the binarization circuit 35
From the demodulated symbol boundary as 1
After the data is divided into 6-bit data, the divided data is converted into 8-bit data by performing a process reverse to the modulation process, that is, 16/8 demodulation to generate reproduced data. In this case, the relative position of the synchronous frame with respect to the head of the modulated recording frame is determined by determining whether the synchronous pattern of the synchronous frame in the continuously obtained reproduction data is one of the synchronous pattern sequences SY0 to SY7. judge.

Next, the demodulation circuit 361 extracts data identification data (data ID) from the reproduced data with reference to the head of the recording frame, and then extracts the data I
D is checked for errors by an ID error detection code (IED), and in order to further protect the reliability, the memory 3 is sequentially read from the beginning of the recording frame and the data ID.
The reproduction data is written to the block 62.

The memory controller 363 has one EC.
When the reproduction data of the 16 recording frames forming the C block is written into the memory 362, the memory 362
, And transfers the inner code parity to the error correction decoding unit 364. The error correction decoding processing unit 364 receives this, performs error correction of the inner code, and when there is an error exceeding the error correction capability of the inner code, determines that the error cannot be corrected and sets the error flag. Generate. The data after error correction and the error flag are written to the memory 362.

The error correction decoding processing section 364
When error correction of all inner codes in the C block is completed,
Next, the memory controller 363 reads the outer code parity from the memory and transfers the same to the error correction decoding processing unit 364 in the same manner, and the error correction decoding processing unit 364 corrects the error of the outer code. Further, the memory controller 363 reads an error flag generated at the time of error correction of the inner code in parallel with the reading of the outer code parity. Error correction decoding processing unit 3
At 64, erasure correction is performed using this error flag. As in the case of the error correction of the inner code, the data after the error correction and the error flag are written into the memory.

Further, the memory controller 363 reads out the error-corrected data in the memory 362 and performs descrambling processing for restoring the scrambled data when generating the recording data. The descrambling process is performed by taking the exclusive OR of the same random data sequence as in the scrambled process and the data after error correction. The data after the descrambled processing read from the memory 362 in this manner is the reproduced data series Dou
Output as t.

FIG. 13 shows a recording format of an ECC block on the optical disk 10 in the present embodiment. In this figure, the contents of each field of the ECC block are indicated by the upper alphabet, and the byte length is indicated by the lower numeral. As shown in the figure, at the beginning of each sector constituting the ECC block, address fields AD0 to AD1 are provided.
5 (only AD0 is shown in the figure).
The sector address fields AD0 to AD15 are ECC
An area for giving address information of each sector constituting a block, and includes a VFO field, an AM field, and a PID.
Field, an IED field, and a PA field.

Here, the address information recorded in each sector address field is information that has not been subjected to error correction processing, and can be detected without releasing error correction. Therefore, by using this address information, even if the optical head goes off the track, the damage can be minimized and the seek time can be reduced.

Generally, a disk is shipped after performing an initialization operation. Initialization is the work of writing data such as the physical address of each sector using emboss bits provided in units of ECC blocks as a mark. DVD-RAM performs an initial inspection (certify) to detect an initial defect during initialization. And defect management. The above-mentioned address fields AD0 to AD15 are recorded on the disk by an initialization operation. The initialization may be performed by the user using an optical disk device having the function. For example, in the optical disk device shown in FIG. 5, the initialization data including the physical address information is processed by the recording data processing unit, and the light beam intensity-modulated by the laser diode 23 via the LD driver 32 is emitted.
The optical disk is irradiated with the light beam via the collimator lens 24, the beam splitter 25, and the objective lens 26, thereby performing an initialization operation.

When actual recording data is recorded on the initialized disk, a correct address is determined based on the start address information ADO of the first sector constituting each ECC block, and a gap from Gap (described later) to immediately before Buffer is determined. Rewrite all areas up to Guard. Therefore, once the head address information AD0 is written by the initialization work, it is not rewritten unless the initialization work is performed again thereafter. On the other hand, the subsequent address information AD1 to AD15 are rewritten each time the ECC block is rewritten. Therefore, the start address information AD0 is important information for determining the address, and usually, as shown in FIG. 13, a plurality of head addresses, preferably two to four, are provided continuously. As described above, by providing a plurality of pieces of address information, it is possible to increase the address reading accuracy. On the other hand, since AD1 to AD15 can be rewritten every time, it is sufficient to provide 1, 2 ADs.

The head address information AD0 may be formed by the emboss bits described above. In such a disk, data can be recorded from any position without performing initialization work.

At the time of data recording, following the first sector address field AD0, a Gap field and a Gua field
An rd1 field is arranged, and after the Guard1 field, a VFO field, a PS field, a DATA field, a DATA field of the first sector, and a PA field are sequentially recorded as phase change marks. After this,
Following the second sector address field AD1 consisting of a VFO field, an AM field, a PID field, an ID field, and a PA field, a PS field, a DATA field of the second sector, and a PA field are sequentially recorded as phase change marks.

Hereinafter, similarly, the sector address field A
Dn (n = 1, 2,..., 15) and the subsequent PS field, DATA field, and PA field have n = 1
It is recorded five times as a phase change mark.

The sixteenth sector address field AD15
Followed by the PS field, the 16th sector DAT
After the A field and the PA field, a Guard2 field and a Buffer field are formed.
One ECC block is completed.

The contents of each field will be described below.

VFO Field The VFO field is a field for providing synchronization to the variable frequency oscillator of the phase locked loop of the read channel bit. The VFO field is located in the ECC block address field (first sector address field) AD0, and is located after AD0. The VFO field following the Gap field and the Guard1 field has a length of 36 bytes, and the VFO field in the second to sixteenth sector address fields has a length of 12 bytes.

AM (Address Mark) Field The address mark is a field for giving byte synchronization to the optical disk apparatus for the next PID field, and is composed of a mark pattern that cannot be generated by 8/16 modulation and has a length of 3 bytes. Have a

PID (physical identification data) field This is 4-byte data consisting of a spare area, a PID number, a sector type, a layer number, and a sector number.

IED (ID Error Detection Code) Field An IED field for detecting an error occurring in the data ID, and is 2-byte data.

PA (postamble) field Data for completing 8/16 modulation of the last byte of the preceding field (IED field or data field), and has a length of 1 byte (16 channel bit length). .

Gap (gap) field This is a field for obtaining a waiting time until the light beam output from the laser diode 23 as a light source rises to a predetermined power, and is 10 + J / 16 bytes, that is, (1)
60 + J) have a channel bit length. Number J is 0 ≦
It changes randomly between J ≦ 15. Variations in the length of the Gap field are compensated for by the length of the Buffer field described later.

Guard 1 field A field arranged next to the Gap field.
It has a length of (20 + K) bytes and repeats a predetermined 16 channel bit pattern (20 + K) times. The number K is
"0" to "0" to shift the position of the phase change mark formed in the field following the Guard1 field to the field following the Guard2 field.
It changes randomly between “7”. The first 20 bytes of the Guard1 field are for protecting the beginning of the subsequent VFO field from signal degradation after overwriting many times, and the contents are ignored when reading data.

Pre-sync code (PS) field This data is used to cause the optical disk device to perform byte synchronization for the next data field. The pre-sync code (PS) field uses a unique channel bit pattern having a length of 3 bytes (48 channel bits). Become.

DATA (Data) Field This is an area where the data of the data field described above is recorded as a phase change mark, and has a length of 2418 bytes.

Guard 2 field A field provided before the buffer field at the end of the ECC block, has a length of (55-K) bytes, and has the same 16-channel bit pattern as that of the Guard 2 field. -K) times. Number K
Is set so that the total length of the Guard1 field and the Guard2 field is 71 bytes. The last 20 bytes of the Guard2 field are for protecting the end of the DATA field after overwriting many times from signal degradation, and the remaining (5 bytes)
(5-K-20) bytes are for absorbing the fluctuation of the actual length of the data written on the optical disk 10, and the contents thereof are ignored when reading the data.

Buffer field This buffer field is provided at the end of the ECC block and changes the actual sector length caused by fluctuations in the rotation speed of the optical disk 10 during data writing, track eccentricity, and the like, and the recording position during phase change recording. This is a region for absorbing the random shift and the deterioration of the start and end. In this example, the region is 140-J / 16.
It has a length of bytes. The Buffer field is provided for each sector in the current DVD-RAM, but is provided for each ECC block, that is, every 16 sectors in the present embodiment. By doing so, according to the present embodiment, the format efficiency can be increased by the reduced amount of the buffer area as compared with the current DVD-RAM.

Hereinafter, the effect of improving the format efficiency according to the present invention will be described with reference to specific numerical examples. In the present embodiment, the ECC block is a 46-byte ECC block address AD0, (10 + J / 1) as shown in FIG.
6) Gap field of byte, Guard1 field of (20 + K) bytes, VFO field of 36 bytes, PS field of 3 bytes, DA of 2418 bytes
2 consisting of a TA field and a 1-byte PA field
488 bytes of first sector data and 12 bytes of VF
O field, 3 byte PM field, 2418 byte DATA field, 4 byte PID field, 2 byte ID field, 1 byte PA field, 3 byte PS field, 2418 byte D field
ATA field, 2444 bytes each consisting of 1 byte PA field, 36660 bytes in total, 2nd to 16th
It is composed of sector data, a Guard2 field of (55-K) bytes, and a Buffer field of (25-J / 16 bytes), and the ECC block length is 383.
It is 89 bytes.

Therefore, according to the present embodiment, the current DVD
-The ECC block length is 38389 bytes / 43152 bytes = 91% as compared with the RAM. That is, the capacity required to record the same data is the current DVD-RA
M is 91%, and the format efficiency is expected to improve by 9%.

In the above embodiment, the emboss pits 16 are used as recognition information indicating the boundaries (start ends) of the ECC blocks, and by counting the number of the boundaries of the ECC blocks, the ECC blocks to which data is to be written are recognized. be able to.

[0098]

As described above, according to the present invention,
Recognition information indicating the boundary of the error correction block is recorded in advance as an emboss pit on the optical disk, and the data of each sector of the error correction block and the address information of the sector are recorded based on the recognition information. The buffer area on the optical disk may be provided in units of error correction blocks, and the buffer area can be greatly reduced as compared with a conventional optical disk that records address information in sector units as emboss pits, thereby improving the format efficiency. I do.

Further, since the position of the error correction block is predetermined on the optical disk, it is possible to write data to an arbitrary error correction block when recording data.
From this aspect, the space on the disk can be used for the data recording area without waste.

Furthermore, although data is error-coded, the address information of the sector is not error-correction-coded, so that the sector address can be recognized in real time without decoding the error-correction block. Can be easily handled even if the address is off, and it is possible to avoid failures such as recording data at an incorrect address when the address is off, and to obtain address information quickly even during a seek. This has the advantage that the waiting time for reading and writing data can be reduced.

Further, in the optical disk apparatus according to the present invention, the land track and the groove track on the optical disk are wobbled in a wobble pattern having a constant period, so that the wobble is obtained from the output of the photodetector for detecting the reflected light from the optical disk. Since a periodic signal corresponding to the pattern can always be obtained irrespective of whether data is written or not, the rotation of the spindle motor can be controlled using the periodic signal even in the case of the ROM type. The time required for recording can be reduced without the need for a re-processing.

[Brief description of the drawings]

FIG. 1 is an enlarged perspective view showing a part of an optical disk according to an embodiment of the present invention.

FIG. 2 is a plan view showing a track pattern on the optical disc.

FIG. 3 is an enlarged plan view showing a part of FIG. 1;

FIG. 4 is a plan view showing a spiral format on the optical disc.

FIG. 5 is a block diagram showing a configuration of an optical disc device according to an embodiment of the present invention.

FIG. 6 is a block diagram of a reproduction data processing unit in FIG. 5;

FIG. 7 is an exemplary flowchart illustrating a processing procedure of a print data processing unit according to the embodiment.

FIG. 8 is a diagram showing the structure of a data frame.

FIG. 9 is a diagram showing the structure of a data ID and its sector information.

FIG. 10 is a diagram showing a logical structure of an ECC block.

FIG. 11 shows a structure of a recording frame.

FIG. 12 is a diagram showing the structure of a data field.

FIG. 13 is a view showing a recording format of an ECC block on the optical disc in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Optical disk 11 ... Disk substrate 12 ... Recording film 13 ... Land track 14 ... Groove track 15 ... Land part of the division area | region of a groove track 16 ... Emboss pit 17a, 17b ... Light beam spot 20 ... Motor driver 21 ... Spindle motor 22 ... Optical head 23 ... Laser diode 24 ... Collimator lens 25 ... Beam splitter 26 ... Objective lens 27 ... Condenser lens 28 ... Photodetector 30 ... Servo circuit 31 ... Recording data processing unit 32 ... LD driver 33 ... Analog arithmetic circuit 34 ... Timing Extraction circuit 35 Binarization circuit 36 Reproduction data processing unit

Claims (13)

[Claims] 1. An optical disc in which data is recorded and reproduced in units of an error correction block composed of a plurality of sectors using a light beam, land tracks and groove tracks which are alternately arranged adjacent to each other, and An optical disc having a plurality of recognition marks formed on a boundary between the land track and the groove track for recognizing a block position. 2. The apparatus according to claim 1, wherein the recognition mark is constituted by embossed pits. 3. The optical disc according to claim 1, wherein the recognition mark is constituted by an emboss pit pattern which is a combination of a plurality of emboss pits. 4. The recognition mark is formed of an emboss pit pattern which is a combination of a plurality of emboss pits forming head address information of a head sector constituting the error correction block. An optical disk according to claim 1. 5. The optical disk according to claim 1, wherein address information of the sector not subjected to error correction coding is recorded. 6. The optical disc according to claim 5, wherein, among the address information, a plurality of head address information of a head sector constituting the error correction block are provided continuously. 7. The optical disk according to claim 1, wherein the land track and the groove track are wobbled at a constant cycle. 8. The optical disc according to claim 1, wherein the recognition mark is provided at a boundary between a land portion provided by dividing the groove track and the land track. 9. The optical disk according to claim 1, wherein each of the error correction blocks has a buffer area. 10. An optical disk device for recording and reproducing data in units of error correction blocks comprising a plurality of sectors by irradiating a light beam onto an optical disk which is driven to rotate, wherein lands arranged alternately and adjacently. Means for detecting the recognition mark of the optical disc comprising a track, a groove track, and a plurality of recognition marks formed on a boundary between the land track and the groove track to recognize a position of the error correction block. An optical disk device, comprising: a unit for writing address information of the sector forming the error correction block based on information from the detected recognition mark. 11. The optical disk device according to claim 10, wherein a plurality of head address information of a head sector constituting the error correction block in the address information are continuously written. 12. A device for writing data in units of error correction blocks and other address information excluding the head address information based on head address information of a head sector constituting the error correction block in the address information. The optical disk device according to claim 10, wherein: 13. The land track and the groove track are wobbled at a constant cycle, a periodic signal whose amplitude changes in accordance with the wobble pattern is generated, and the rotation of the optical disc is controlled based on the periodic signal. 13. The optical disk device according to claim 10, wherein the optical disk device is operated.