JP2002237056A - Optical recording medium and optical recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical recording medium which can record more user data with the same recording medium size by reducing the redundancy in the optical recording medium used for header parts, attached parts, etc., other than actual user data. SOLUTION: Three different 1-bit codes are allocated to discriminate codes of a PID part according to the lengths of prepits which are arranged zigzag and addresses are dispersed and arranged over multiple identification information parts to shorten a header part of conventionally 128 bytes to about 39 bytes.

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 is recorded in a pit shape at the time of manufacturing the optical disk, and includes a non-rewritable header section 906 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”.
3456 "is recorded. The position information is 4 bytes long, but a 2-byte error detection code is added to confirm whether the position information has been correctly reproduced. In addition, since the position information signal is recorded at the same density as the data recorded in the recording unit, it is necessary to reproduce the signal using a PLL as in the case of the data, and a VFO is provided. In order to strengthen the reliability as a peripheral device application, it is quadruple recorded and has a total length of 128 bytes.

[0006]

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 portion, 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, 4.7G
When recording the capacity of B, when the format efficiency is 100% and when the format efficiency is 75.9% as described above, in the latter case where the format efficiency is low, a lot of information must be packed around a unit area. Therefore, 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 problems, and an object of the present invention is to create a disk format having a 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.

[0009]

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. Is composed of at least one or two pre-pits, and is composed of a first pre-pit, a second pre-pit following the first pre-pit and a space, and has a length P1 of the first pre-pit and the second pre-pit. Are compared, and a plurality of codes are represented according to the comparison result of the lengths of the prepits, 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 a concentric or continuous spiral groove and an inter-groove portion, and stores information in one of the groove portion and the inter-groove portion or in both of the groove portion and the inter-groove portion. In an optical recording medium having a recording / reproducing section for recording, the recording / reproducing section is divided into sectors by an identification information section at regular intervals, and the identification information section has a pre-pit area and a non-pre-pit area alternately at regular intervals. The pre-pit area includes at least one pre-pit, represents a plurality of codes according to the length of the pre-pit, and is used as address information by combining the plurality of codes. I do.

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 prepit. 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, wherein 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 periphery 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 disposed at the head of the identification information portion, and the address mark portion is located on the inner peripheral side and on the track center line of the groove portion and the inter-groove portion, respectively. It is characterized by including a pre-pit region provided at a predetermined distance on the outer peripheral side, and arranged so as not to be 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, in the optical recording medium of the present invention, the identification information section has a substantially constant length on a track line, and an identification information area is provided on inner and outer tracks adjacent to the identification information section. The identification information section exists, and is arranged 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 the present invention is characterized in that the address information includes 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 for prepits having 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.

[0021]

(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,
102 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
A PID part 105 recording address information, and an address mark part 107 provided beforehand at the head of the identification information part
It is composed of

The PID portion shown in FIG. 1 has 106 prepit areas each representing 1-bit information by a combination of a prepit and space pattern shown in FIG. It is formed repeatedly. 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. Are arranged as shown in FIG.

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. 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 of the present invention. Reference numeral 705 denotes an optical disk, and reference numeral 703 denotes 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. Also, ZCL
In the case of the V 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.

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, the block address can be determined in several quarters of the sector, 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, the code "S" has a pit length different from 8Tw and 14Tw used for the codes "0" 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 as code "S", and codes "0" and "1" can be determined.
Can be easily distinguished from each other, and the detection accuracy of the code “S” can be improved. Here, the lengths of 8 Tw, 14 Tw, and 30 Tw are used as the pit lengths of P1 and P2. However, the pit length does not need to be limited to the above numerical values. It can be determined according to ease. In the reproduced signal, the difference in the pit length between P1 and P2 is determined from the reproduced waveform to identify the code.

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. For the length of the prepit in the address mark portion, for example, a combination of the prepit and the space of the code “S” in the PID portion is used. In order to increase the detection accuracy, the address mark portion is preferably formed of a 30 Tw prepit having a prepit length sufficiently longer than the light spot as shown in FIG. 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 as 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 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 of the physical structure of the pre-pit area, the codes are assigned to the codes "0", "1" and "S" 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, three kinds of 1s are identified by using two pits P1, P2, and S1 and one space in the pre-pit area arranged in a staggered manner for identifying the code of the PID portion.
By allocating a bit code and distributing and arranging the addresses over a plurality of identification information sections, the identification information section, which used to be 128 bytes in the past, can be shortened to 39 bytes. It is possible to perform formatting with a reduced degree, which has the effect of dramatically increasing the recording capacity of the optical disk.

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 comprises 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 represents 1-bit information by a combination of patterns composed of pre-pits and spaces shown in FIGS. 11 and 12 described later.
06 pre-pit area is set to 8 at regular intervals (4 bytes).
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, and the prepit area of the groove track and the prepit area of the land track are arranged complementarily. 6, the pre-pit region is prevented from overlapping the same position in the radial direction.

The ending point of the groove track of the recording / reproducing section is arranged to be skewed every time the track is moved. As shown in FIG. 6, the ending position of the next groove track is shifted by 4 bytes. 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 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 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, 11
01 is a light spot, 1102 is a groove (groove) track formed in advance on the optical disk, and 1103 is an inter-groove (land) track interposed between grooves.

In the schematic diagram of the optical disk structure shown in FIG. 11A, an identification information section 1106 is provided at the head of a groove track or land track, and is located on the inner or outer circumference side from the groove track center line or land track center line. 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, a part (1 bit) of the address information of the land sector in the staggered pre-pits is used as the pre-pit area 1 and a part (1 bit) of the address information 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 according to 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.

The 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, three types of codes are assigned as follows.
Codes “0”, “1”,
Although “S” is allocated, the code allocation method does not need to be limited to the above-described allocation method, and the codes “0”, “1”, and “S” may be allocated in ascending order of the prepit detection window width. The symbol “S” is a block address or P
This is a code representing the head of the ID block, and it is preferable that the reliability be higher than other codes. The modulation method of data to be recorded on the recording / reproducing unit is used in DVDs and the like.
In the case of the -16 modulation method, the longest run of the recording data is 14T.
Since it is w, the ID code “S” used for the identification information section can use 16 Tw or 24 Tw which does not comply with the 8-16 modulation rule, thereby improving the ID detection capability of the identification information section.

As described above, three 1-bit codes are assigned to the codes of the PID portion according to the length of the prepits arranged in a staggered manner, and the addresses are distributed over a plurality of identification information portions. This arrangement makes it possible to shorten the header part, which used to be 128 bytes in the past, to about 39 bytes, to enable formatting with reduced redundancy by the header part, and to dramatically increase the recording capacity of the optical disk. effective.

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". Identified by
This has the effect of improving the read reliability of the address information.

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 sign is “0” when the detection time width is 8 Tw, the sign is “1” when the detection time width is 16 Tw, and the sign is “S” when the detection time width is 24 Tw.

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

In the case of the difference signal, the reproduced waveform is vertically symmetric with respect to the 0 level in the pre-pit area 1 and the pre-pit area 2 due to the configuration of the pits arranged in a staggered manner. The rising / falling of the detection reference edge in the pre-pit area 1 and the pre-pit area 2 is reversed. Further, by using the difference signal, it is possible to detect the identification information region by using 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. Therefore, when the light spot crosses the prepit shifted half a track, a very large difference signal (TE signal) is generated. Then, the identification information part is detected by using this, and a gate signal is generated so that the address information can be read with high reliability.

Further, in the embodiment of the present invention, the end edge of the pre-pit is arranged at 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 is applied to the collimator lens 803 and the beam splitter 8.
04, condensed on the optical disk 801 through the convergence means 805. The condensed light spot is
The light is then reflected and diffracted on the light detecting means 80 through a converging means 805, a beam splitter 804, and a condenser lens 806.
The light is condensed on 7. 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. The TE signal output from the reproduction signal calculation means is transmitted to the tracking control means 810. R which is the output of the reproduction signal calculation means
The F signal and the TE signal 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 drives the actuator 811 by the voltage output according to the TE signal, and controls the tracking position of the light spot to a desired track position on the surface of the optical disk 801.

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 having different reflectivities of the phase-change optical disk by the light spot subjected to the focus control and the tracking control.

The address detecting means 812 outputs the codes "0", "1", "1", "2" according to the pulse width and pulse pattern of the RF signal and 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.

[0075]

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

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takashi Ishida 1006 Kazuma Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. F-term (reference) 5D029 KB03 WA28 WA31 5D044 DE38 DE57 DE58 DE70 5D090 AA01 CC12 CC14 DD03 FF12 FF17 GG10 GG17 GG28 GG36

Claims (15)

[Claims] 1. A light having a concentric or continuous spiral groove and an inter-groove portion and a recording / reproducing portion for recording information in one of the groove portion and the inter-groove portion or both of the groove portion and the inter-groove portion. In the recording medium, the recording / reproducing unit is divided into sectors at regular intervals by an identification information unit,
The identification information section includes an area in which pre-pit areas and non-pre-pit areas are alternately arranged at regular intervals, and one pre-pit area includes at least one or two pre-pits; The first pre-pit is composed of a second pre-pit that continues across a space, and the length P1 of the first pre-pit is compared with the length P2 of the second pre-pit. An optical recording medium, wherein a plurality of codes are represented in accordance with each other, and address information is represented by combining the plurality of codes. 2. The code is a first code "0" when the prepit length is P1> P2, a second code "1" when P1 <P2, and a third code when P2 = 0. 2. The optical recording medium according to claim 1, wherein 1-bit information represented by an identification code "S" is represented as address information by combining the 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 of the groove and the groove. In the recording medium, the recording / reproducing unit is divided into sectors at regular intervals by an identification information unit,
The identification information section includes an area in which pre-pit areas and non-pre-pit areas are alternately arranged at regular intervals, and the pre-pit area includes at least one pre-pit,
An optical recording medium, wherein a plurality of codes are represented according to the length of the pre-pits, and address information is obtained by combining the plurality of codes. 4. The method according to claim 1, wherein the code is based on a prepit length.
A 1-bit information represented by a first code "0", a second code "1", and a third identification code "S", and address information is obtained by combining the three codes. Item 4. The optical recording medium according to Item 3. 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 groove, and the pre-pit area is simultaneously formed on the inner circumferential side and the outer circumferential side of the same location on the track center line of the groove and the groove. 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. An apparatus according to claim 1, wherein an address mark section is disposed at a leading portion of said identification information section, and said address mark section is a mirror surface section. The optical recording medium according to item 1. 9. An address mark portion is disposed at a leading portion of the identification information portion, and the address mark portion is provided at predetermined positions on an inner peripheral side and an outer peripheral side from the track center line of the groove and the groove, respectively. 2. A pre-pit region which is provided at a distance and which is 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. Item 8. The optical recording medium according to any one of items 7. 10. The identification information section has a substantially constant length on a track line, and identification information areas are present on inner and outer tracks adjacent to the identification information section. The light according to any one of claims 1 to 9, wherein the light is arranged 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. recoding media. 11. The apparatus according to claim 1, wherein the address information includes an error detection code (parity).
The optical recording medium according to any one of the above items. 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. A pre-pit in the pre-pit area,
3. The optical recording medium according to claim 2, wherein the starting position or the ending position of the prepit is the same for prepits having different lengths. 15. Address information is constituted by combining three kinds of codes, a first code "0" representing one bit, a second code "1", and a third identification code "S", The address information is an optical recording medium composed of one or more prepits, an optical head that irradiates a light spot with a light beam focused on the optical recording medium to record and reproduce a signal, and a reflected light from the optical head. Detecting means for receiving light by a plurality of light receiving elements, a focus controlling means for controlling a focal position of the light spot on a recording surface, a tracking controlling means for controlling a position of the light spot on a track, and the light detecting means An optical recording / reproducing apparatus comprising an address detecting means for detecting the address information from an output of the optical recording / reproducing apparatus.