JP2002260238A - Optical recording medium and optical recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical recording medium to which more user data can be recorded compared with a same-sized optical recording medium by reducing redundancy spent for all but user data such as the header and accessory parts of the optical recording medium. SOLUTION: In order to identify the code of a PID part, three different kinds of one-bit codes are allocated in accordance with the length of a prepit arranged in staggered form, and addresses are distributed and located over identification information parts, and thereby usual 128 bites used for the header part are reduced to 39 bites.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium (optical recording medium) for reproducing information by irradiating a converged light beam onto a recording medium and detecting reflected light from the recording medium. is there.

[0002]

2. Description of the Related Art In recent years, there has been a great demand for optical discs for video applications, and higher densities and higher speeds have been desired so that higher picture quality and longer time video recording can be performed. for that purpose,
It is important to develop a recording medium capable of recording finer information, but it is essential to reduce a portion that does not directly contribute to the information capacity, for example, a so-called overhead area such as an address area.

FIG. 9 is a diagram showing the configuration of a track on which a light beam of a conventional optical disk tracks (for example,
"Nikkei Electronics" October 20, 1997 Issue 1
DVD-RAM format optical disk described on pages 67-186). In FIG. 9, reference numeral 901 denotes a sector which is an information unit; 902, an identification information portion which is recorded in a pit shape at the time of manufacturing an optical disc and indicates non-rewritable address information; and 903, a recording / reproducing portion capable of recording / reproducing information. The recording / reproducing unit includes a groove track 904 and a land track 9 sandwiched between the groove tracks.
Reference numeral 05 denotes an optical disk capable of recording signals on both the land track and the groove track. The identification information section includes a header section 906 which is recorded in a pit shape when the optical disc is manufactured and cannot be rewritten, and a mirror section 907.

[0004] The arrangement in one sector of a conventional optical disk will be described with reference to FIG. It is constituted by a series of sectors 1001 which is the minimum unit of recording and reproduction. The sector has a header portion 1004 having a length of 128 bytes, and 2
The recording / reproducing unit 1003 of 567 bytes and the mirror unit 1005 of 2 bytes have a total of 2697 bytes. The recording / reproducing section is a data section 1007 in which user data is recorded, a VFO (Variable Frequency Oscillator) for pulling in a PLL (Phase Looked Loop) necessary for reproducing a recorded signal, and a margin area. The buffer is included in the appendix 1 of 1006 and the appendix 2 of 1008.

In a conventional optical disk, position information is provided in a header section 1004 in order to recognize which sector of which part of the disk the light beam follows. Here, the position information provided in the header section 1004 indicates the position information of the sector constituting the header section. That is, as shown in FIG.
The header of the sector 901 specified by “56” is “12”.
Position information "3456" is recorded.

The position information has a length of 4 bytes, but a 2-byte error detection code is added to confirm whether the position information has been correctly reproduced. In addition, since the signal of the position information is recorded at the same density as the data recorded in the recording unit, it is necessary to reproduce the position information by using the PLL similarly to the data, and the VFO is provided. Furthermore, in order to strengthen the reliability as a peripheral device of a computer, the data is recorded four times and has a total length of 128 bytes.

[0007]

However, the above-mentioned prior art has the following problems. That is, in the case of a conventional optical disc, for example, when recording 2048 bytes of user data in one sector, a 128-byte header section is used to recognize which part of the disc the light beam is following. And a 2-byte mirror section indicating a boundary between the header section and the recording / reproducing section;
68 bytes of the auxiliary part 1 and 81 bytes of the auxiliary part 2 which are used for recording in the recording / reproducing unit, pulling in the PLL, or used as a margin area for recording data are required. In the data section, in the case of a DVD, the recording data itself is modulated for error correction. 8
When performing -16 modulation, a 2418-byte data portion is required. In order to record 2048 bytes of user data on the disk in this manner, a total of 2697 bytes of sector length is required. That is, the format efficiency is 2048/2697 = 0.759, and the disk use efficiency (format efficiency) when recording a signal on the disk is 75.9%. That is, the format includes redundancy of 24.1%.

For example, when recording a capacity of 4.7 GB,
Format efficiency of 100% and 75.
In the case of the format efficiency of 9%, in the latter case where the format efficiency is low, a lot of information has to be packed per unit area, so that there is a problem that the quality of the recording / reproducing signal is deteriorated as compared with the former.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to create a disk format having high format efficiency, thereby spending a header part and an auxiliary part. An object of the present invention is to provide an optical disk capable of recording more data on an optical disk of the same size by reducing redundancy.

[0010]

In order to solve the above-mentioned problems, an optical recording medium according to the present invention has concentric or continuous spiral grooves and inter-groove portions. An optical recording medium having a recording / reproducing portion for recording information in one or both of the groove portion and the inter-groove portion,
The recording / reproducing section is divided into sectors by an identification information section at regular intervals, and the identification information section includes an area in which pre-pit areas and non-pre-pit areas are alternately arranged at regular intervals. The region is composed of at least one or two pre-pits, and is composed of a first pre-pit, a second pre-pit that continues across the first pre-pit and a space, and has a length P1 of the first pre-pit and the second pre-pit. Compare the length P2 of the two pre-pits,
A plurality of codes are represented according to the comparison result of the lengths of the pre-pits, and address information is represented by combining the plurality of codes.

In the optical recording medium of the present invention, the code is a first code "0" when the pre-pit length is P1> P2, and a second code "1" when P1 <P2, A case where P2 = 0 is represented as 1-bit information with a third identification code “S”, and address information is obtained by combining the three codes.

Further, the optical recording medium of the present invention has concentric or continuous spiral grooves and inter-grooves, and information is written in one of the grooves or inter-grooves or in both the grooves and inter-grooves. In an optical recording medium having a recording / reproducing unit for recording, the recording / reproducing unit is divided into sectors by an identification information unit at regular intervals, and the identification information unit includes:
A prepit area including a prepit area and a non-prepit area alternately arranged at regular intervals, wherein the prepit area includes at least one prepit, and represents a plurality of codes according to a length of the prepit; Are combined into address information.

Also, in the optical recording medium of the present invention, the codes are a first code "0", a second code "1", and a third identification code "S" according to the length of the pre-pit. 1 bit information, and the address information is obtained by combining the three codes.

Further, the optical recording medium of the present invention assigns address information to a block address unit composed of a plurality of continuous sectors, and the address information is a plurality of continuous identification information sections in the block address. And a combination of codes in a plurality of pre-pit areas in the identification information section.

Further, in the optical recording medium of the present invention, the pre-pit region is provided on a track center line of the groove portion and the inter-groove portion, and an inner circumference of the same location on the track center line of the groove portion and the inter-groove portion. It is characterized in that the pre-pit areas are arranged so as not to exist simultaneously on the side and the outer peripheral side.

Further, in the optical recording medium of the present invention, the pre-pit region is provided at a predetermined distance from the track center line of the groove portion and the inter-groove portion to an inner peripheral side and an outer peripheral side, respectively, and It is characterized in that the prepit area is not simultaneously present on the inner peripheral side and the outer peripheral side of the groove portion and the inter-groove portion on the track center line.

Further, the optical recording medium of the present invention is characterized in that an address mark portion is arranged at the head of the identification information portion, and the address mark portion is a mirror surface portion.

Further, in the optical recording medium of the present invention, an address mark portion is arranged at a leading portion of the identification information portion, and the address mark portion is formed inside the groove portion and the inter-groove portion from above a track center line. A pre-pit region which is provided at a predetermined distance on the circumferential side and the outer circumferential side, and which is arranged so as not to be simultaneously present on the inner circumferential side and the outer circumferential side on the track center line of the groove portion and the inter-groove portion. Features.

Further, in the optical recording medium of the present invention, the identification information section has a substantially constant length on a track line, and identification information areas are provided on inner and outer tracks adjacent to the identification information area. The identification information area exists, and is arranged so as to move in the track direction at a constant interval shorter than the length of the identification information area from the inner peripheral side to the outer peripheral side.

Further, the optical recording medium of the present invention is characterized in that the address information contains an error detection code (parity). The optical recording medium according to the present invention is characterized in that the address information includes a sector number. An optical recording medium according to the present invention is an optical recording medium having a plurality of information surfaces, wherein address information includes a number (layer number) indicating the information surface.

Further, the optical recording medium of the present invention is characterized in that the prepits in the prepit area have the same start or end position as prepits of different lengths.

Further, the optical recording / reproducing apparatus of the present invention uses three kinds of codes of a first code "0" representing one bit, a second code "1", and a third identification code "S". Address information is constituted by combining the optical information, the address information is constituted by one or more pre-pits, and an optical head for recording and reproducing a signal by irradiating a light spot with a light beam focused on the optical recording medium. Light detecting means for receiving reflected light from the optical head with a plurality of light receiving elements; focus controlling means for controlling a focal position of the light spot on a recording surface; and controlling the position of the light spot on a track. It is characterized by having tracking control means and address detection means for detecting the address information from the output of the light detection means.

[0023]

(Embodiment 1) Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration diagram of an optical disc (optical recording medium) according to Embodiment 1 of the present invention. FIG. 1 shows a part of a configuration diagram of a track formed concentrically or spirally on an optical disk. 101 is a groove track, 1
02 is a land track. Here, the groove track is a guide groove formed in a spiral shape in advance, and the land track is a track between grooves sandwiched between the groove tracks. The groove track and the land track are wobbled in the radial direction in advance, the phase difference between the land track and the groove track is 0, and the track has a ZCLV structure.

The tracks are separated by the identification information section 103. The recording / reproducing section 104 is provided between the identification information sections, and the tracks are divided into sectors by the identification information section. The recording / reproducing section records and reproduces rewritable user data, and the identification information section pre-records address information and the like.

Further, the identification information section comprises a PID section 105 on which address information is recorded, and an address mark section 107 provided beforehand at the head of the identification information section. The PID part of FIG. 1 further includes a pre-pit area 106 that represents 1-bit information by a combination of patterns composed of pre-pits and spaces shown in FIG.
Are repeatedly formed eight times at regular intervals (4 bytes). The prepits in the prepit area are on the center line of the land track or groove track, and the prepit area of the groove track and the prepit area of the land track are arranged complementarily, and the prepit area overlaps the same position in the radial direction. Figure 1 avoiding
It is arranged like. The end point of the groove track of the recording / reproducing unit is arranged to be skewed every time the track is moved, and the end position of the next groove track is shifted by 4 bytes as shown in FIG. With this, ZCL
Conventional optical disk (DVD-RAM) in V format
In this configuration, the identification information sections are not arranged in a straight line in the radial direction of the track, but are skewed for each track.

FIG. 7 shows an overall view of the optical disk of the present invention. 705 is an optical disk and 703 is an identification information section. Although not shown, the identification information section includes a pre-pit area as shown in FIG. The identification information section is arranged so as to draw an arc while skewing at a constant interval from the inner circumference to the outer circumference on the optical disc. In the case of the ZCLV format, the identification information section is skewed for each zone. Since the identification information portion occupies a larger area of the mirror surface (mirror surface portion) than the recording / reproducing portion,
The amount of light diffraction at this portion is smaller than the amount of light diffraction at the recording / reproducing unit. Therefore, in the case of an optical disc (a two-layer disc) having a plurality of information surfaces, a light spot is formed on the second layer. During reproduction, when the light spot passing through the first layer includes a plurality of identification information areas, the amount of light reaching the second layer increases, so that crosstalk relatively increases between layers. . In order to reduce crosstalk between layers, the length of the identification information section is shortened, and the identification information area is skewed for each track as shown in FIG. To reduce crosstalk.

Next, a method of inserting address information of the optical disk of the present invention will be described with reference to FIG. In the optical disc of the present invention, one ECC block recorded in the recording / reproducing area is recorded with a minimum unit of 64 Kbytes. One ECC block is recorded in sectors of 2 Kbytes. Therefore, one ECC block is composed of 32 sectors.

As with the user data to be recorded in the recording / reproducing area, one piece of address information (block address) is assigned to each ECC block.
However, unlike the conventional method in which one address is completed for each sector (the method used in DVD-RAM),
The address information is distributed and arranged in a plurality of continuous sectors. For example, by reading the identification information part of eight sectors, the block address information is decoded.

Reference numeral 202 in FIG. 2 indicates that 32 sectors are consecutively formed in the minimum unit of the block address. 32 sectors are divided into four PID blocks, and one PID block
The ID, for example, PID0 includes eight consecutive sectors (sector # 0 to sector # 7). 20 PID blocks
The configuration shown in FIG. In the PID block, a parity-added block address (201) of 8 bits per sector, that is, a total of 8 × 8 = 64 bits is repeatedly arranged.

As shown in FIG.
The address information is decoded by reading the entire block address of 32 sectors in the prior art.
By dividing the ID block into four, it is possible to determine the block address with 1/4 of the number of sectors, and the access capability is improved. Also, reading the PID block four times is effective in improving the reliability in reading one block address.

Next, the structure of the address information will be described with reference to FIG. 8-bit information of “S1001101” is assigned to the PID portion of sector # 0 as address information. By reading the identification code "S", PI
It is identified that it is the start position of the D block (the head position of the address). Next, a code “00110101” is assigned as information of the first PID portion of the sector # 1. Similarly, the address information of the PID portion of sector # 2 to sector # 7 is read. In the case of FIG. 2, the block address is composed of eight sectors, and “S100110100” is read in order from sector # 0 to sector # 7.
110101... 1001101 ”and a total of 64 bits of information, and these 64 bits of information are block address information with parity.

Next, the physical configuration of the pre-pit area 106 will be described with reference to FIG. In FIG. 3, reference numeral 301 denotes a light spot, which is scanned from left to right in the figure. Reference numeral 302 denotes a pattern of a pre-pit area formed on a disk representing a code “0”, 303 denotes a pattern of a pre-pit area formed on a disk representing a code “1”, and 304 denotes a pattern on a disk representing a code “S”. 5 is a pattern of a pre-pit area formed in the first embodiment.

The pattern "0" at 302 is composed of two pits P1, P2 and a space S1 sandwiched between P1, P2. The pit length of P1 is a mark length corresponding to 14 times the length of Tw when the channel clock is Tw, the mark length P2 is a mark length equivalent to 8 times the length of Tw,
S1 is a space length equivalent to eight times Tw. Here, the magnitude relationship between the lengths of P1 and P2 is P1> P
It is 2. S1 = P2.

The pattern "1" at 303 is composed of two pits P1, P2 and a space S1 sandwiched between P1, P2. The pit length of P1 is a mark length corresponding to eight times the length of Tw when the channel clock is Tw, P2 is a mark length corresponding to 14 times the length of Tw,
S1 is a space length equivalent to eight times Tw. Here, the magnitude relationship between the lengths of P1 and P2 is P1 <P
It is 2. S1 = P1.

The pattern "S" 304 is composed of one pit P1. The pit length of P1 is a mark length corresponding to 30 times the length of Tw assuming that the channel clock is Tw. S1 = P1.

Code "0", code "1", code "S" is P
1, P2 is assigned as follows according to the magnitude relation.

(1) P1> P2: code “0” (2) P1 <P2: code “1” (3) Only P1 (P2 = 0): code “S” Here, code “S” is changed to code “0”. The pit length is different from 8Tw and 14Tw used in “1” and “1” and longer than 14Tw. By doing so, the case where a prepit having a length equal to or more than a certain value is detected can be determined to be the code "S", which can be easily distinguished from the codes "0" and "1", and the detection of the code "S" It is possible to improve accuracy.

Here, the pit length of P1 and P2 is 8T.
Although the lengths of w, 14 Tw, and 30 Tw were used, the pit length does not need to be limited to the above values, and can be determined according to the size of the light spot irradiated on the disk and the ease of signal detection. is there. In the reproduced signal, the P
The code is identified by determining the difference in pit length between 1 and P2 from the reproduced waveform.

Next, the sector structure of the block address will be described with reference to FIG. A block address is formed by a series of sectors 401, which is the minimum unit for recording and reproduction. The sector 401 includes an identification information section 402 and a recording / reproducing section 403. The identification information section 402 includes a PID section having a length of 32 bytes and an address mark section (AM section) having a length of 7 bytes. (The length per byte here is a byte unit of user data. In the case of 8-15 modulation, one byte is 15 Tw).

The address mark portion has a mirror surface as shown in FIG. The address mark part is arranged at the head of the identification information part, and has the purpose of detecting the head of the identification information part. When the address mark portion is detected, the signal processing circuit generates a gate signal for reading the PID portion, and can accurately read the address information of the PID portion.

Here, in addition to the case where the address mark portion is formed on the mirror surface shown in FIG. 1, as shown in FIG. 5, the pre-pits are staggered at a predetermined distance from the center line of the land track and the groove track. May be arranged. As the length of the prepit in the address mark portion, for example, a combination of the prepit and the space of code “S” in the PID portion is used. The address mark portion is preferably formed of a 30 Tw pre-pit having a pre-pit length sufficiently longer than the light spot as shown in FIG. 3 in order to increase the detection accuracy. Further, by using the prepits arranged in a zigzag pattern as address marks, the address mark portion can be detected using the differential signal of the two-segment photodetector, and the detection accuracy of the address mark portion can be further improved. It is.

The recording / reproducing unit 403 performs 8-16 modulation, 8-
241 to which modulation such as 15 modulation and (1, 7) modulation is applied
A data portion having a length of 8 bytes (including ECC), and a PLL required to reproduce a signal recorded in the data portion
(Varia (Varia) to pull in (Phase Looked Loop)
ble Frequency Oscillator) area, a 12-byte auxiliary part 1 including a buffer or the like which is a margin area, and a 12-byte auxiliary part 2. The appendix 1 is arranged before the data section, and the appendix 2 is arranged after the data section.

When recording 2048 bytes of user data, the above-mentioned identification information section of 39 bytes and the recording / reproducing section 24
A total of 2481 bytes of sector length is required including 42 bytes. That is, the format efficiency is 2048/2
481 = 0.825, and the disc use efficiency (format efficiency) when recording a signal on the disc is 82.81.
5%. In other words, the format includes 17.5% redundancy. This is because conventional optical disks (eg, DVDs)
−RAM) format is much smaller than the redundancy of 24.1%.

In the first embodiment, as an example, the physical configuration of the pre-pit area has been described in which the codes "0", "1" and "S" are assigned by combining two pits and one space. It goes without saying that the same result can be obtained by replacing the pits and spaces with a combination of two spaces and one pit as the physical configuration of the pre-pit area.

As described above, the three types of P1s, P2, and S1 in the pre-pit area arranged in a staggered manner and one space are used to identify the code of the PID portion.
By allocating a bit code and distributing addresses across a plurality of identification information sections, it is possible to shorten the identification information section, which used to be 128 bytes conventionally, to 39 bytes. Thus, it is possible to achieve a format in which the recording capacity of the optical disc is reduced, and the recording capacity of the optical disc is drastically increased.

Embodiment 2 Hereinafter, Embodiment 2 of the present invention will be described with reference to the drawings. FIG. 6 shows a configuration diagram of an optical disc (optical recording medium) according to Embodiment 2 of the present invention. FIG. 6 shows a part of a configuration diagram of a track formed concentrically or spirally on an optical disk. 601 is a groove track, and 602 is a land track. Here, the groove track is
The land track is a guide groove formed in a spiral shape in advance, and the land track refers to a track between the grooves, which is sandwiched between the groove tracks. The groove track and the land track are wobbled in the radial direction in advance, and the phase difference between the wobble of the land track and the groove track is 0, thereby forming a ZCLV structure.

The tracks are separated by an identification information section 603. A recording / reproducing section 604 is provided between the identification information sections, and the tracks are divided into sectors by the identification information section. The recording / reproducing section records and reproduces rewritable user data, and the identification information section pre-records address information and the like.

Further, the identification information section 603 includes a PID section 605 in which address information is recorded, and an address mark section 607 provided at the head of the identification information section. The PID portion in FIG. 6 has a pre-pit area 606 representing 1-bit information by a combination of patterns composed of pre-pits and spaces shown in FIG. 11 and FIG. It is formed repeatedly. The prepits in the prepit area are arranged in a staggered manner at a predetermined distance from the center line of the land track or the groove track.
The pre-pit area of the groove track and the pre-pit area of the land track are arranged complementarily, and are arranged as shown in FIG. 6 in which the pre-pit area is prevented from overlapping at the same position in the radial direction.

The end point of the groove track of the recording / reproducing section is arranged to be skewed every time the track is moved, and the end position of the next groove track is shifted by 4 bytes as shown in FIG. Thus, unlike the conventional optical disk (DVD-RAM) in the ZCLV format, the identification information sections are not aligned in a line in the radial direction of the track, but are skewed for each track.

FIG. 7 shows an overall view of the optical disk. 705
Is an optical disk, and 703 is an identification information section. Although not shown, the identification information section includes a pre-pit area as shown in FIG. The identification information section is arranged so as to draw an arc while skewing at a constant interval from the inner circumference to the outer circumference on the optical disc. In the case of the ZCLV format, the identification information section is skewed for each zone.

Since the identification information portion has a larger area occupied by the mirror surface (mirror surface portion) than the recording / reproducing portion, the amount of light diffraction at this portion is smaller than the amount of light diffraction at the recording / reproducing portion. Therefore, in the case of an optical disk (a two-layer disk) having a plurality of information surfaces, when a light spot is being reproduced on the second layer, the light spot passing through the first layer includes a plurality of identification information areas. In such a case, since the amount of light reaching the second layer increases, crosstalk relatively increases between the layers. In order to reduce crosstalk between layers, the length of the identification information section is shortened, and the identification information area is skewed for each track as shown in FIG. To reduce crosstalk.

The method of inserting address information and the configuration are the same as those described in the first embodiment and FIG.

Next, the physical configuration of the pre-pit area 606 will be described with reference to FIG. In FIG. 11, 110
Reference numeral 1 denotes an optical spot, 1102 denotes a groove (groove) track formed on the optical disk in advance, and 1103 denotes an inter-groove (land) track interposed between the grooves.

In the schematic diagram of the optical disk configuration shown in FIG. 11A, an identification information section 1106 is provided at the head of a groove track or a land track, and is located on the inner or outer circumference from the center of the groove track or the center of the land track. There is a pre-pit 1104 which is arranged with a half track shift. The identification information part is divided into two parts according to the arrangement position of the staggered pre-pits.
One is a pre-pit area 1 (1108) and the other is a pre-pit area 2 (1109). Reference numeral 1107 denotes a recording / reproducing unit, which is an area for recording / reproducing data. The recording data is recorded on both the land track and the groove track.

Here, part (1 bit) of the address information of the land sector in the staggered prepits is used as part of the prepit area 1 and part of the address information (1 bit) of the groove sector.
Bit) is allocated to the pre-pit area 2. Here, a part of the land sector address information is stored in the pre-pit area 2,
A part of the address information of the groove sector may be assigned to the pre-pit area 1.

In FIG. 11A, the length of the prepit in the prepit area differs depending on the information of each bit. Prepit length is 8T according to 1-bit information
It is possible to take different lengths of w, 16 Tw and 24 Tw. However, the end edge positions of the pre-pits substantially coincide with each other for all pre-pit lengths. Matching the end edge positions has the effect of increasing the detection accuracy. It is also possible to accurately detect the length of the pit by synchronizing with the PLL at the trailing edge.

A method of assigning codes will be described. Three 1-bit codes are assigned according to the length of the prepits arranged in a staggered manner. For example, when the pre-pit length is 8 Tw, the code is “0”, and the pre-pit length is 16 Tw.
The length code is "1", and the prepit length is 24 Tw, and the code is "S". Here, as the three types of codes, codes “0”, “1”, and “S” are allocated in ascending order of the detection window width of the pre-pit, but it is necessary to stick to the above-mentioned allocation method. , The codes “0”, “1”,
“S” may be assigned.

The code "S" is a code indicating the block address or the head of the PID block, and it is preferable that the reliability be higher than other codes. In the case where the modulation method of the data to be recorded in the recording / reproducing unit is the 8-16 modulation method used in DVDs and the like, the longest run of the recording data is 14 Tw, so the code “S” of the ID used in the identification information unit is 8 -16Tw or 24T not in -16 modulation rule
By using w, the ability to detect the ID of the identification information section can be improved.

As described above, three 1-bit codes are assigned to the codes of the PID portion in accordance with the length of the prepits arranged in a staggered manner, and the addresses are distributed over a plurality of identification information portions. By arranging the header portion, it is possible to shorten the header portion, which used to be 128 bytes, to about 39 bytes, thereby enabling a format in which the redundancy by the header portion is reduced, and dramatically increasing the recording capacity of the optical disk. There is.

In the present invention in which the address information is constructed by combining not only the codes "0" and "1" but also three codes including the code "S", the start position of the PID block or the block address is indicated by the code "S". Thus, there is an effect that the reading reliability of the address information can be improved by the identification.

Next, a detection method will be described. When detecting using the sum signal (sum signal of the divided photodetector),
A reproduced waveform as shown in FIG. 11B is obtained. Assuming that the reference position is the first falling edge, detection is performed by measuring a time interval from the reference position to the next rising edge. In this case, the code is “0” when the detection time width is 8 Tw, the code is “1” when the detection time width is 16 Tw, and the detection time width is 24 T.
At the time of w, the symbol is "S".

When the detection is performed using the difference signal (the difference signal of the photodetector divided in the track direction), a reproduced waveform as shown in FIG. 11B is obtained. If the reference position is the first falling / rising edge, then the next rising /
It is detected by measuring the time interval until the falling edge.
In this case, the code is “0” when the detection time width is 8 Tw, the code is “1” when the detection time width is 16 Tw, and the detection time width is 24.
At the time of Tw, the sign is “S”.

In the case of the difference signal, due to the configuration of the pits arranged in a zigzag pattern, the reproduced waveform is vertically symmetric with respect to the 0 level in the pre-pit area 1 and the pre-pit area 2. The rising and falling of the detection reference edge in the pre-pit area 1 and the pre-pit area 2 are reversed.

Further, by using the difference signal, it is possible to detect the identification information area by the envelope of the difference signal by using the prepits arranged in a staggered manner. Even when data is recorded or unrecorded in the recording / reproducing area, the difference signal is substantially at the 0 level, so that when the light spot crosses the prepit shifted half a track, a very large difference signal (TE signal) is obtained. By using this, the identification information section is detected, and a gate signal is generated, so that the address information can be read with high reliability.

In the embodiment of the present invention, the ending edge of the pre-pit is set to the same position with respect to all the pre-pit lengths. However, as shown in FIG. The position may be set to be the same for all the pre-pit lengths.

(Embodiment 3) Embodiment 3 of the present invention will be described below with reference to the drawings. FIG. 8 shows a configuration diagram of an optical disk device according to Embodiment 3 of the present invention. 8, reference numeral 801 denotes an optical disk, 802 denotes a semiconductor laser, 803 denotes a collimating lens, 804 denotes a beam splitter, 805 denotes a converging unit, 805 denotes a converging lens, 806 denotes a light detecting unit, 807 denotes a light detecting unit, 808 denotes a reproduction signal calculating unit,
Reference numeral 809 denotes a focus control unit, 810 denotes a tracking control unit, 811 denotes an actuator, 812 denotes an address detection unit, and 813 denotes a laser driving unit.

Next, the reproducing operation will be described. The optical disk 801 is, for example, the optical disk described in the first embodiment, and the light spot is converged on a recording / reproducing unit, an identification information unit, and the like of the optical disk 801 to read information. The light beam emitted from the semiconductor laser 802 passes through a collimator lens 803, a beam splitter 804, and a converging unit 805, and is focused on an optical disk 801. The condensed light spot is reflected and diffracted on the optical disk 801, and converges 805, a beam splitter 804, and a condensing lens 80.
After passing through 6, the light is condensed on the light detecting means 807.

The condensed light outputs a voltage signal corresponding to the light amount of each of the light receiving elements A, B, C, and D on the light detecting means, and the reproduction signal calculating means 808 performs four arithmetic operations on the voltage signal. . The FE signal output from the reproduction signal calculation means is transmitted to the focus control means 809. Reproduction signal calculation means 8
08 is output from the tracking control unit 81.
Sent to 0. The RF signal and the TE signal output from the reproduction signal calculation means 808 are transmitted to the address detection means 812.

The focus control means 809 drives the actuator 811 by the voltage output according to the FE signal, and controls the focus position of the light spot on the optical disk 801 surface. When performing recording and reproduction on an optical disk having a plurality of information surfaces such as a two-layer disk, the focus control means controls the focus surface to control the focal position of the light spot on a predetermined recording layer. The tracking control means 810 outputs a voltage to the actuator 8 according to the TE signal.
11 to control the tracking position of the light spot to a desired track position on the optical disk 801 surface.

The information recorded on the optical disk is read by reading the uneven pre-pits on the optical disk or the dark and light marks and spaces of the phase change optical disk having different reflectivities by the light spot subjected to the focus control and the tracking control.

The address detecting means 812 outputs the codes "0", "1", and "0" in accordance with the pulse width and the pulse pattern of the RF signal and the TE signal at the portion corresponding to the identification information section in the output of the reproduction signal calculating means. S "is detected and temporarily stored in the memory as a part of the address information in sector units.
When the parity-added block address information (64 bits) of all the sectors in the block is read, the read 6 bits are read.
The block address number is calculated from the 4 bits, and the corresponding block address number is recognized. After recognizing the block address number, desired data is reproduced or recorded in ECC block units.

In the first to third embodiments of the present invention, the length of the identification information portion is, for example, 39 bytes. However, the numerical value is a design matter and is not limited to 39 bytes. However, wobbles of the guide grooves in the recording / reproducing section existing between the guide grooves and the guide grooves of the groove track and the land track are intermittent in the identification information section. Therefore, a wobble phase error may occur before and after the identification information section. In the present invention, it is desirable to select the frequency or cycle of the wobble at a frequency or cycle that does not cause a phase error before and after the phase of the wobble is before and after the identification information section. For example, by setting the wobble cycle to a unit of 13 bytes, there can be virtually three wobbles between the 39-byte identification information section, and no wobble phase error occurs before and after the identification information section. It is. Conversely, it is possible to determine the length of the identification information section to be an integer multiple of the frequency of the wobble for the same reason. As described above, by setting the length of the identification information section to an integral multiple of the wobble period, there is no phase error of the wobble before and after the identification information section, and extra time such as PLL re-locking before and after the identification information section is obtained. This makes it possible to record and reproduce data without spending time, thereby improving the reading reliability of the optical disk.

Further, in Embodiments 1 to 3 of the present invention, the reference numerals in FIG. 3 are changed to three types. However, the pits and spaces of the three reference numerals "0", "1" and "S" shown in FIG. There is no need to stick to a combination of lengths.
It is also possible to use a combination of three groove tracks. For example, in FIG. 3, 14 Tw-8 Tw-
The 8 Tw pit-space-pit combination is denoted by code "0", but the 12 Tw-9 Tw-9 tw pit-
The combination of space and pit may be set to code “0”.

The land track code “0” is changed to 14
The combination of a pit-space-pit of Tw-8Tw-8Tw, and the code “0” of the groove track is set to 12
A pit-space-pit combination of Tw-9Tw-9Tw may be used. As described above, PI
By differentiating the combination of the pits and spaces in the D section between the land track and the groove track, it is possible to easily distinguish the address information of the land track or the groove track when reading the code of the PID section, This has the effect of improving the reliability of reading address information.

Further, it becomes easy to distinguish a crosstalk signal from an adjacent track, for example, a crosstalk signal in an area between the prepit areas arranged in a zigzag pattern, thereby improving the reliability of reading address information. It is possible to improve. Further, by making the combination of the land track and the groove track different for not only the code “0” but also the codes “1” and “S”, it is possible to further improve the reliability of reading the address information.

In the first to third embodiments of the present invention, the length of the pre-pit area is set to 2 bytes (30 Tw in 8-15 modulation), but the end of 2 bytes of the pre-pit area has a space of about 1 Tw or 2 Tw. An area may be included. For example, in FIG. 3, 14 Tw-8 Tw-
The 8 Tw pit-space-pit combination is denoted by code "0", but the 12 Tw-8Tw-8Tw-2Tw pit-space-pit-space combination obtained by adding a 2 Tw space to the end is denoted by code "0". ".

Similarly, in FIG. 3, 8Tw-8Tw-14T
The pit-space-pit combination of w is denoted by reference numeral “1”, and the 8Tw-8Tw-12Tw-2Tw pit-space-pit-space combination obtained by adding a 2Tw space to the end is denoted by reference numeral “1”. ". Similarly, in FIG. 3, the 30 Tw pit is denoted by the symbol “S”, but a 28 Tw−2 Tw pit-space combination with a 2 Tw space added to the end portion is denoted by “S”.

By providing a space area at the end of the pre-pit area of about 2 Tw as described above, when cutting pits arranged in a staggered pattern as shown in FIG. Can have a margin for the response time, and the staggered pre-pits can be easily created.

[0079]

As described above, there are three types of 1 in accordance with the length of the prepits arranged in a staggered manner for identifying the code of the PID portion.
By allocating a bit code and distributing and arranging addresses over a plurality of identification information sections, it is possible to shorten the header section, which used to be 128 bytes in the past, to about 39 bytes. Thus, it is possible to achieve a format in which the recording capacity of the optical disc is reduced, and the recording capacity of the optical disc is drastically increased.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an optical disk (optical recording medium) according to Embodiment 1 of the present invention.

FIG. 2 is a diagram for explaining how to insert address information of the optical disc according to the first embodiment of the present invention;

FIG. 3 is a diagram for explaining a physical configuration of a pre-pit area of the optical disc according to the first embodiment of the present invention;

FIG. 4 is a view for explaining a sector structure of a block address of the optical disc in the first embodiment of the present invention;

FIG. 5 is a configuration diagram of an optical disc (optical recording medium) according to the first embodiment of the present invention.

FIG. 6 is a configuration diagram of an optical disc (optical recording medium) according to Embodiment 2 of the present invention.

FIG. 7 is an overall view of an optical disc according to the first and second embodiments of the present invention.

FIG. 8 is a configuration diagram of an optical disc device according to a third embodiment of the present invention.

FIG. 9 is a configuration diagram of a conventional optical disk.

FIG. 10 is a diagram for explaining a sector structure of a conventional optical disc.

FIG. 11 is a configuration diagram of an optical disc in Embodiment 2 of the present invention.

FIG. 12 is a configuration diagram of an optical disc in Embodiment 2 of the present invention.

[Explanation of symbols]

 Reference Signs List 101 groove track 102 land track 103 identification information section 104 recording / reproducing section 105 PID section 106 prepit area 107 address mark section

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takashi Ishida 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd. 5D029 WA31 5D090 AA01 BB04 CC12 DD01 EE15 FF17 FF25 GG02 GG07 GG10 GG17

Claims (15)

[Claims] 1. A light having a concentric or continuous spiral groove and a groove, and a recording / reproducing unit for recording information in either the groove or the groove or both the groove and the groove. In the recording medium, the recording / reproducing unit is divided into sectors by an identification information unit at regular intervals, and the identification information unit includes an area in which pre-pit areas and non-pre-pit areas are alternately arranged at regular intervals, 1
One of the pre-pit areas is composed of at least one or two pre-pits, and is composed of a first pre-pit, a second pre-pit that continues across the first pre-pit and a space, and has a length P1 of the first pre-pit. And a length P2 of the second pre-pit, and a plurality of codes are represented according to a comparison result of the length of the pre-pit, and address information is represented by combining the plurality of codes. recoding media. 2. The code has a prepit length of P1> P2.
Is a first code “0”, a case where P1 <P2 is a second code “1”, and a case where P2 = 0 is a third identification code “S”. 2. The optical recording medium according to claim 1, wherein address information is obtained by combining three codes. 3. A light having a concentric or continuous spiral groove and a groove, and a recording / reproducing unit for recording information in either the groove or the groove or both the groove and the groove. In the recording medium, the recording / reproducing unit is divided into sectors by an identification information unit at regular intervals, and the identification information unit includes an area in which pre-pit areas and non-pre-pit areas are alternately arranged at regular intervals, The optical recording medium according to claim 1, wherein the prepit area includes at least one prepit, represents a plurality of codes according to a length of the prepit, and combines the plurality of codes to obtain address information. 4. The code represents 1-bit information having a first code “0”, a second code “1”, and a third identification code “S” according to the length of a prepit. 4. The optical recording medium according to claim 3, wherein address information is obtained by combining three codes. 5. Address information is assigned to a block address unit composed of a plurality of continuous sectors, wherein the address information includes a plurality of continuous identification information sections in the block address and a plurality of identification information sections in the identification information section. The optical recording medium according to any one of claims 1 to 4, wherein the optical recording medium is configured by combining codes in the pre-pit area of (1). 6. The pre-pit area is provided on the track center line of the groove and the inter-groove portion, and the pre-pit area is simultaneously formed on the inner peripheral side and the outer peripheral side of the same location on the track center line of the groove and the inter-groove section. The optical recording medium according to any one of claims 1 to 5, wherein the optical recording medium is arranged so that no area exists. 7. The pre-pit region is provided at a predetermined distance from the track center line of the groove portion and the inter-groove portion to the inner peripheral side and the outer peripheral side, respectively, and the center of the track of the groove portion and the inter-groove portion is provided. The optical recording medium according to any one of claims 1 to 5, wherein a pre-pit area does not exist simultaneously on an inner peripheral side and an outer peripheral side on the line. 8. The apparatus according to claim 1, wherein an address mark section is disposed at a head of the identification information section, and the address mark section is a mirror surface section. The optical recording medium according to the paragraph. 9. An address mark portion is arranged at a leading portion of the identification information portion, and the address mark portion is provided at predetermined positions on an inner circumferential side and an outer circumferential side from a track center line of the groove and the groove, respectively. Provided at a distance, and
8. The pre-pit region according to claim 1, further comprising a pre-pit region arranged so as not to be simultaneously present on an inner peripheral side and an outer peripheral side of the groove portion and the inter-groove portion on the track center line. Optical recording medium. 10. The identification information section has a substantially constant length on a track line, and has identification information areas on inner and outer tracks adjacent to the identification information area. 10. The optical disc apparatus according to claim 1, wherein the optical discs are arranged so as to move in the track direction at a constant interval shorter than the length of the identification information area from the inner circumference to the outer circumference.
The optical recording medium according to any one of the above items. 11. The optical recording medium according to claim 1, wherein the address information includes an error detection code (parity). 12. The optical recording medium according to claim 1, wherein the address information includes a sector number. 13. An optical recording medium having a plurality of information surfaces, wherein the address information includes a number (layer number) representing the information surface. Item 2. The optical recording medium according to item 1. 14. The pre-pit in the pre-pit area, wherein the start or end position of the pre-pit is the same for pre-pits of different lengths.
The optical recording medium according to the above. 15. A first code “0” representing one bit,
Address information is configured by combining three types of codes, a second code “1” and a third identification code “S”, wherein the address information is an optical recording medium composed of one or more pre-pits; An optical head that irradiates a light spot with a light beam focused on the optical recording medium to record and reproduce a signal, light detection means that receives reflected light from the optical head with a plurality of light receiving elements, and Focus control means for controlling a focal position on a recording surface, tracking control means for controlling the position of the light spot on a track, and address detection means for detecting the address information from an output of the light detection means, Optical recording and reproducing device.