JP2006085863A - Optical disk and recording and reproducing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk in which a medium can be recognized at high speed by a recording and reproducing apparatus of a different generation even when it is a medium of a different generation by unifying format structure recorded in a control zone. <P>SOLUTION: The optical disk is provided with a user data zone which is a region in which clock information is previously fixed-recorded at fixed interval and which can record and reproduce user information, and a control zone in which control information specifying a medium is recorded, and has track structure formed in helical form or concentric circular form, wherein one track in the control zone is constituted of one physical address segment region and a plurality of control unit regions, each control unit region is a region in which no clock information is included and control information and synchronism information for reproducing the control information are previously fixed-recorded. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical disk and an apparatus for recording and reproducing an optical disk, and more particularly to a format structure of information recorded on an optical disk and a recording / reproducing apparatus capable of recognizing an optical disk having the format structure.

Currently, optical discs having various format structures have been developed and used.
For example, as commercially available optical disks, there are a phase change medium capable of writing information, a magneto-optical medium and a dye medium, and a preformat medium dedicated to reading information.

There are various types of phase change media having different data structures, such as CD-RW, DVD + RW, DVD-RW, DVD-RAM, and Blu-ray.
The magneto-optical medium includes MO and MD, and the dye medium includes CD-R, DVD + R, and DVD-R.
Further, examples of the preformat medium include a CD-ROM and a DVD-ROM.
Many of these types of media are incompatible because of different recording capacities, format structures of recorded data, recording / reproducing methods, and the like.

For example, in a DVD-RAM dedicated recording / reproducing apparatus, a DVD-RW belonging to the same phase change medium cannot be recorded / reproduced even though the DVD-RAM can be recorded / reproduced.
Further, many CD-ROM playback devices built in many personal computers can play CD-ROMs and CD-Rs but cannot play DVD-ROMs with higher recording density.
Further, a 130 MB MO dedicated recording / reproducing apparatus cannot record and reproduce a 230 MB MO having the same format structure and the same recording / reproducing method.

Thus, the existence of a large number of media that are incompatible with each other causes confusion for users and is not preferable for manufacturing and development manufacturers.
Therefore, a recording / reproducing apparatus capable of recording / reproducing with respect to a large number of incompatible media (for example, CD-ROM, DVD-ROM, CD-R, DVD-R, DVD-RAM) with one apparatus is commercially available. However, it is desirable that a high recording density medium expected to be sold in the future can be recorded and reproduced by the same single device.
In general, an apparatus for recording / reproducing a high recording density medium that will be developed in the future is desired to be able to perform recording / reproducing of a low recording density medium that has been circulated at present and in the past. That is, backward compatibility is required.

On the other hand, a recording / reproducing apparatus that has been developed and marketed in the past is capable of recording / reproducing a medium that was commercially available at the time of its sale, but of course a high recording density medium that did not even have a standard at the time of its sale. Recording and playback are not possible.
That is, the previous generation recording / reproducing apparatus cannot ensure the upward compatibility of recording / reproducing the medium of the next generation high recording density.
One of the factors hindering such upward compatibility is a format structure for recording data on an optical disk medium.

Hereinafter, an example of a format structure of a conventional optical disc will be described.
FIG. 9 is a schematic configuration diagram of an embodiment of a conventional optical disc format structure, and FIG. 10 is an explanatory diagram of the contents of each block of the conventional optical disc format structure.
In the recording area of the conventional optical disk shown in FIG. 9, a large number of tracks are concentrically formed, the lead-in zone 10 is in the outermost area and the lead-out zone 30 is in the innermost area. A user data zone 20 in which the user can record and reproduce is provided in the area. The lead-in zone 10 is on the side where the optical disk starts to be used, and is disposed on the side close to the outer periphery of the medium. The lead-out zone 30 is arranged on the center side of the medium.

Each of the lead-in zone 10 and the lead-out zone 30 includes three zones as shown in FIG.
In the lead-in zone 10, a buffer zone 11, a control zone 12, and a test zone 13 are arranged in order from the side closer to the outer periphery of the medium.
In the lead-out zone 30, a buffer zone 31, a control zone 32, and a test zone 33 are arranged in order from the side closer to the center (inner circumference) of the medium.
The test zone (13, 33) is an area used for confirming the recording / reproducing operation condition.

In the control zone (12, 32), information for identifying the medium is stored in advance.
For example, information indicating the format structure of the medium, vendor information, substrate lot information, information on recording and reproducing power, and the like are stored in the control zone.
The information stored in the control zone (12, 32) is data that is fixedly stored so that it cannot be rewritten in advance before shipment in the form of pits or wobbles, and is so-called preformatted data.
Such a control zone (12, 32) is not an area where a general user who purchases and uses a medium can store and reproduce his / her own data.

In general, a magneto-optical disk has a “spiral structure” in which grooves (grooves) and lands (projections) are alternately arranged in a spiral from the outer periphery to the inner periphery of a medium.
The groove is a guide groove for tracking, and a convex land is disposed between adjacent grooves.
In addition, the pre-formatting of the magneto-optical disk is performed on a stamper for forming a substrate. Laser light is irradiated on the stamper surface in a spiral shape, and pits indicating grooves and physical addresses are formed by exposure processing. .
A groove or land for recording and reproduction is called a track, but one cycle is one track.
User information is recorded on a land or a groove, and there are a method of recording only on a land or a groove, and a method of recording on both a land and a groove.

FIG. 11 is an explanatory diagram of a data structure per track of a conventional optical disc.
One track is composed of a plurality of “physical blocks” (Bo to B _n−1 ), and one physical block includes one physical address segment BA and a plurality of data segments (DS _{0 to} DS ₃₇ ). It consists of.
In one track in the user data zone 20, the track address is recorded in the first segment BA, and user data is stored in the data segment (DS _{0 to} DS ₃₇ ).

FIG. 12 is an explanatory diagram of the data structure of one data segment.
The data segment (DSn) is composed of four areas: a clock mark area A1, a prewrite area A2, a data area A3, and a postwrite area A4.
The clock mark area A1 is an area for generating an external clock serving as a recording / reproduction reference timing, and is an area having a length of 12 DCB. Here, one DCB (Data Channel Bit) means one data channel bit length, that is, one clock width.

Clock information is written in the clock mark area A1 with 4DCB as one unit. As shown in FIG. 12, the clock information is alternately written in the adjacent groove G1 and land L1 every 4DCB.
In this conventional recording / reproducing apparatus for recording / reproducing an optical disk, the clock information recorded in the clock mark area A1 is read in advance and multiplied by using a PLL (Phase Locked Loop) so as to equally divide the data segment area. To generate an external clock. The user data is recorded / reproduced with respect to the data area A3 with reference to the external clock.

FIG. 12 shows a data structure in which one data segment DSn has a length of 532 DCB as an example of a conventional optical disc. In one data segment DSn, a 4DCB prewrite area A2, a 512DCB data area A3, and a 4DCB postwrite area A4 are arranged behind the 12DCB clock mark area A1.
When there are 37 data segments DSn in one physical block as shown in FIG. 11, the data length of the entire data segment is 20216 DCB.

FIG. 13 shows an explanatory diagram of the data structure of one track in the control zone (12, 32).
Also in the control zone, as shown in FIG. 11, one track is composed of a plurality of physical tracks (B _{0 to} B _n-1 ), and a physical address segment BA is arranged at the head of one physical block. Is done.
However, in the control zone (12, 32), a plurality of control segments (CS _{0 to} CS ₃₇ ) are arranged instead of the data segment shown in FIG.
In the control segment CSn, information for identifying the optical disc (referred to as control data) is written in advance.
The information written in the control segment CSn is fixedly prewritten at the time of substrate generation so that the user cannot rewrite the information.
In FIG. 13, the physical address segment BA and the control segment CSn are both 532 DCB.

FIG. 14 is an explanatory diagram of the data structure of one control segment.
One control segment CSn includes a clock mark area C1, a pre-buffer area C2, a synchronization area C3, a control data area C4, and a post-buffer area C5.
Here, the clock mark area C1, the pre-buffer area C2, and the post-buffer area C5 are the same as those in FIG.
In the synchronization area SYNC (C3), a synchronization pattern for synchronization is read in advance for reading the data recorded in the control data area C4.
One unit of control data is recorded in one control data area C4. One unit includes a plurality of predetermined management information.

The control data is a set of several units and forms one set of control information.
For example, when one set of control information is formed by three units, one unit is recorded in each of three consecutive control segments, and one set of control information is recorded in the three control segments.
If one set of control information is composed of 10 pieces of management information, the first unit has 3 pieces of management information, the second unit has 5 pieces of management information, and the third unit has 3 pieces of management information. Two pieces of management information are recorded. As shown in FIG. 13, when the control segment CS has 37 blocks, the same control information constituting one set of 3 units is repeatedly recorded at least 12 times.
In FIG. 14, a 510 DCB area composed of a synchronization area C3 and a control data area C4 is formed in a wobble shape.
The 1-bit data of the control information stored in the control data area is configured by converting into a plurality of bit length data having two types of phases. In other words, 1-bit data of control information is formed by bi-phase modulation and making the groove wall meander.

FIG. 15 is an explanatory diagram of the biphase modulation rule.
One bit of control information recorded in the control data area C4 is defined as having a length of 1 CDB (Control Data Bit). In FIG. 15, the length of 1 CDB is 6 DCB. That is, the modulation data that is 1 bit (1 CDB) of the control information has a length (1CDB = 6DCB) corresponding to six clock lengths.
In FIG. 15, the modulation data representing “0” having a length of 1 CDB is defined as “111000”, and the modulation data representing “1” having a length of 1 CDB is defined as “000111”.
In this case, control data having the number of bits corresponding to a length of 510 DCB = 85 CDB is stored in the areas (C3, C4) in the control segment CS shown in FIG.

As described above, the control data formed by making the side wall portion of the groove into a wobble shape is detected by a push-pull signal detection method.
FIG. 16 is an explanatory diagram for detecting control data by the push-pull signal detection method.
When light is irradiated to the groove portion where the wobble is formed, the diffracted light is condensed by the objective lens 51 and received by the two-divided photodetector (PD) 52.

The received diffracted light is converted into electrical signals (I ₁ , I ₂ ), and a push-pull signal (I ₁ -I ₂ ) is output by the differential amplifier 53.
Control data is reproduced using this push-pull signal.
The push-pull signal is input to the converter 54, compared with a predetermined slice level, and converted into a binary signal.
Thereafter, the synchronization detection circuit 55 first detects a synchronization signal SYNC (Synchronization) from the synchronization data recorded in the synchronization area C3.
Thereafter, in the biphase demodulation circuit 56, using the synchronization signal SYNC as a trigger, the push-pull signal is phase-synchronized to perform biphase demodulation, and the control data is reproduced.
As shown in FIG. 15, since 1 bit of control information is formed as modulated data with redundancy, it is correct even when the phase of the channel clock and the control data are not completely synchronized during bi-phase demodulation. Control data can be played back.
When data is recorded by pits, the control data of the control data is obtained by using a signal (SUM = I ₁ + I ₂ ) obtained by summing _two output signals (I ₁ , I ₂ ) from the photodetector. Playback is performed.

An optical disc has been proposed in which the type of optical disc to be reproduced can be identified regardless of the type of drive device (see Patent Document 1).
JP-A-9-231578

The recording capacity of optical discs has increased with technological progress, but standards have been established for each era. Then, an optical disc medium is manufactured so as to conform to the standard, and a recording / reproducing apparatus is developed so that data can be recorded and reproduced on the optical disc medium conforming to the standard.
For example, in the ISO standard MO, discs having different recording capacities such as 130 MB, 230 MB, 1.3 GB, and 2.3 GB have been manufactured in order of generation.
In the situation where there are several generations of optical disc media in this way, when developing an apparatus capable of recording / reproducing for a medium having a large recording capacity of the next generation, it is considered that a medium having a small recording capacity of the previous generation can usually be recorded / reproduced. Is done.

That is, a recording / reproducing apparatus compatible with the next generation optical disc is developed that maintains backward compatibility and is compatible with the previous generation optical disc.
On the other hand, the recording / reproducing apparatus developed in the era when only the previous generation optical disc existed cannot recognize the next generation optical disc. For example, when a later-generation optical disc is inserted into a previous-generation recording / reproducing apparatus, after a retry is repeated for a few dozen seconds to several minutes, an unreadable error is displayed.
Further, there may be a problem that a personal computer or the like to which the recording / reproducing apparatus is connected becomes inoperable without giving an unreadable error display.

One cause of this phenomenon is that the density of the format structure of the area in which the control data is recorded differs between the previous generation and the next generation media.
In general, the format of a later generation optical disc medium is formulated so as to maintain backward compatibility and increase the recording capacity. That is, the format of each area of the block structure as shown in FIGS. 11, 12, 13, and 14 is maintained, and the physical length of each area is reduced.

FIG. 17 shows a comparison diagram of data structures of data segments of two generations of optical disks.
FIG. 17A shows a data structure of a previous generation medium using a light source with a red wavelength (640 nm). Here, one bit has a length of 0.265 μm, and one data segment is composed of 532 DCB (= bit). Therefore, the length of one data segment is about 141.0 μm.

On the other hand, FIG. 17B shows a data structure of a medium of the next generation that uses a light source having a blue wavelength (405 nm).
In this case, since high-density recording can be performed, one bit has a length of 0.133 μm, which is about half the length of the previous generation medium.
Therefore, in the next generation medium, even if the length of one data segment is the same 532 DCB (= bit), it is about 70.8 μm, and the physical length is reduced.

Such a situation is the same for a control segment having a similar block structure.
The recording / reproducing apparatus for the previous generation has been developed on the assumption that the previous generation medium having relatively long data length and control data as shown in FIG. When a generation medium is inserted after recording long data and control data, the data and control data cannot be reproduced accurately.
This is because the previous generation apparatus cannot obtain a sufficiently large push-pull signal conforming to the specifications when data of a physically reduced size is reproduced.
FIG. 18 is an explanatory diagram of the relationship between the wobble length and the data bit length.

18A shows the wobble length of the previous generation optical disc, and FIG. 18B shows the wobble length of the next generation optical disc.
In FIG. 18A, 1DCB = 1 bit = 0.265 μm, and 1 wobble length is 1CDB = 6DCB = 0.265 × 6 = 1.59 μm.
When such a previous generation optical disc is reproduced by a previous generation recording / reproducing apparatus, a push-pull signal having a good amplitude can be obtained.
On the other hand, in the next generation optical disc shown in FIG. 18B, 1DCB = 1 bit = 0.133 μm, and 1 wobble length is 1CDB = 6DCB = 0.133 μm × 6 = 0.798 μm.

When such a later generation optical disc is reproduced by a later generation recording / reproducing apparatus having a relatively small light beam spot, a push-pull signal having a sufficiently large amplitude as shown by a dotted line can be obtained. However, when reproduction is performed by a previous generation recording / reproducing apparatus having a large light beam spot, only a push-pull signal having a small amplitude can be obtained as shown by a solid line.
The small amplitude of the push-pull signal means that the resolution is poor and the data cannot be read accurately.

  In particular, when the information in the control data area is recorded in a physically reduced size, the previous generation device cannot recognize the medium at all, and the above-described trouble occurs. become.

FIG. 19 shows the relationship between the pit length and the data bit length when pits are used as the preformat data.
In the case of the optical disk of the previous generation shown in FIG. 19A, 1DCB = 1 bit = 0.265 μm and 1 pit length = 1 CDB = 6 DCB = 1.59 μm.
In the case of the optical disk of the next generation in FIG. 19B, 1DCB = 1 bit = 0.133 μm, and 1 pit length = 1 CDB = 0.798 μm.

In this case as well, as in the case shown in FIG. 18B, when the next generation optical disc is reproduced by the previous generation recording / reproducing apparatus, a SUM signal having an appropriate amplitude cannot be obtained. So the same trouble occurs.
As described above, the data format structure such as the control zone in the conventional optical disc remains the same, and when the physical length of each data is reduced to increase the density, the recording / reproducing apparatus for the previous generation Generation optical discs cannot be recognized, causing troubles such as inoperability.

  In addition, when high density is achieved by changing the layer structure of the medium itself (for example, magnetic super-resolution media, magnetic domain expansion media), the next generation that only supports media that have been densified by other methods Even a recording / reproducing apparatus for recording / reproducing cannot be used for recording / reproducing.

  Therefore, the present invention has been made in consideration of the above circumstances, and has been devised in the format structure of the control zone, and can be inserted into the recording / reproducing apparatus regardless of the previous generation and the next generation optical discs having different recording capacities. It is an object of the present invention to provide an optical disc capable of recognizing a recorded medium and a recording / reproducing apparatus for recording / reproducing the optical disc.

  The present invention is an area in which clock information is fixedly recorded in advance at fixed intervals, and includes a user data zone in which user information can be recorded and reproduced, and a control zone in which control information for specifying a medium is recorded. An optical disk having a track structure formed in a spiral shape or a concentric shape, wherein one track in the control zone is composed of one physical address segment area and a plurality of control unit areas. It is an object of the present invention to provide an optical disc characterized in that the unit area is an area in which control information and synchronization information for reproducing the control information are fixedly recorded in advance without including clock information.

  Here, the control information includes at least generation specifying information, medium type, and error check data, and the set of control information is divided and recorded in a plurality of control unit areas, and is recorded in one track of the control zone. The same control information may be repeatedly arranged.

  The information formed in each control unit area is fixedly recorded in advance by a wobble formed by making the wall surface of a groove separating each track into a meandering shape, or has a predetermined data length on each track. It is preliminarily recorded in a fixed manner by pits formed as concavo-convex shapes.

  Further, even if the physical data length of each control unit area is changed in the unit recording length of data recorded in the user data zone, the physical data length of the control unit area designed during the development of the previous generation is changed. The synchronization information and the control information may be repeatedly fixed and recorded in the control unit area so as to be the same.

  Further, the optical disc of the present invention may be a medium in which the user information is recorded only in one of a land portion or a guide groove separated by a guide groove formed in a spiral shape or a concentric shape.

  Furthermore, the optical disk of the present invention may be a medium in which the user information is recorded in both a guide groove formed in a spiral shape or a concentric shape and a land portion separated by the guide groove.

The present invention also provides a recording / reproducing apparatus capable of recording / reproducing user information on / from an optical disc having the above characteristics.
Further, for any one of the optical discs, a detection unit for detecting control information included in the control zone, and whether the optical disc is a medium capable of recording and reproducing user information from the detected control information. The recording / reproducing apparatus provided with the medium recognition part which recognizes is provided.

According to the present invention, the control unit area in the control zone is fixedly recorded in advance with a structure that includes control information and synchronization information and does not include clock information. Even a recording / reproducing apparatus for use can recognize different generations of optical disks.
Further, the recognition of the medium of different generation optical discs can be made faster than before, and the utilization efficiency when the user reproduces the medium can be improved.

Hereinafter, the present invention will be described in detail based on the embodiments shown in the drawings. In addition, this invention is not limited by this.
<Example 1>
FIG. 1 shows an embodiment of the format structure of the control zone of the optical disk according to the present invention.
Here, the numerical values such as the physical length of each area indicate the media (previous generation medium) developed in the previous generation among the optical disks of the present invention.
The global disk format structure of the optical disk of the present invention is the same as the conventional structure shown in FIG. 10, and the test zone, buffer zone, and user data zone have the same format structure as the conventional one. That is, the format structure of the user data zone is provided with a plurality of physical blocks for each track, and each block (B _{O to} B _n-1 ) has the format structure shown in FIGS. .

In the present invention, the control zone (12, 32) has a characteristic format structure as shown in FIG.
In FIG. 1, the control zone of the optical disk of the present invention is composed of a physical address segment (BA) and a plurality of control unit areas in one track.
One control unit area includes a synchronization area SY and a control data area CD.
Further, dummy data is arranged in the fractional area after the control unit is arranged. The dummy data is data obtained by patterning data such as “0000...”, For example. The fractional area may be a straight area in which no information is recorded.
The portion of the physical address segment BA in FIG. 1 occupies a length of 532 DCB, and preformat information similar to the conventional one is recorded in this area.

Information recorded in the control unit area is prewritten by wobbles or pits.
One control unit has a data length of 510 DCB. If 1DCB of the previous generation medium is 0.265 μm, the data length of one control unit is 0.265 × 510 = 135.15 μm.

FIG. 2 is an explanatory diagram of a structure example of the control zone of the medium of the present invention.
One set of control information (CD1, CD2, CD3) recorded in the control zone is recorded in several control data areas.
1 and 2 show a case where control information for one set is recorded in three control data areas, that is, three control unit areas (U00, U01, U02).

  In addition, a large number of control units are arranged in one track. For example, as shown in FIG. 2, the same control information (CD1, CD2, CD3) recorded in set 1 (SO1) is stored. N sets are recorded in the rear area. That is, the same control information (CD1, CD2, CD3) is repeatedly recorded in set k (S0k) and set n (S0n).

FIG. 3 shows a specific example of information contents recorded in the control data area of the present invention.
In the control data area of unit 0 (U00), a standard version, a vendor code, a recording / reproducing method, a medium type, and error check data are recorded.
Here, the standard version is information for specifying the generation of the medium. The medium type is information indicating the type of reading and writing of the medium, and indicates a difference such as write-once or rewritable.

In units (U01) and unit 2 (U02), bytes 0 to 6 are areas (vendor free areas) that can be used freely by the vendor of the medium, and byte 7 stores error check data. The
In this embodiment, the case where information for one set is divided and recorded in three areas is shown, but the present invention is not limited to this. Generally, n pieces of information for one set (n = 1, 2,. ...)) May be recorded separately.

FIG. 4 shows an explanatory diagram of an embodiment of the format structure of the previous generation medium in the optical disc of the present invention.
FIG. 4 shows the relationship between the structure of the data zone 20, the test zone 13 and the control zone 12 in the medium.
FIG. 4 shows the structure of a land / groove recording medium for recording information on both the land and the groove.
Here, the data zone 20 and the test zone 13 have the same structure as the conventional medium. As shown in FIGS. 11 and 12, the physical address segment BA and the subsequent data segments (DS0 to D37) Consists of That is, the user data is divided into units called data segments, and information such as the clock mark A1 shown in FIG. 12 is arranged in each data segment.

One data segment is composed of 532 DCB, and if 1DCB = 0.265 μm, the physical length of one data segment is 532 DCB = about 141 μm.
On the other hand, the control zone 12 has a structure as shown in FIG. 1, and includes a physical address segment BA and a plurality of control units. Here, the physical address segment BA has the same configuration as the data zone 20 and has a data length of 532 DCB.

In addition, as shown in FIG. 1, one control unit has a data length of 510 DCB = about 135 μm.
As shown in FIG. 1, one control unit is composed of a synchronization area (SYNC) and a control data area (CD), but a clock mark area C1 and a prebuffer area C2 as shown in FIG. There is no post-buffer area C5. That is, clock information is not included.

Therefore, when data is reproduced from the medium of the present invention, an external clock generated with reference to the clock mark C1 is not used.
Instead, the information is reproduced by a fixed clock having a frequency close to that of the external clock, and as shown in FIG. 4, information in the control unit area (synchronization area SYNC and control data area) redundant immediately after the physical address segment BA is redundant. The phase-synchronized reproduction is performed using the characteristics.
In FIG. 4, the physical address segment BA of all the zones and the information of the synchronization area SYNC and the control data area of the control zone are information that is formed in advance as wobbles and cannot be rewritten.
As described above, since the area where the information such as the clock mark is conventionally recorded is eliminated, the area where the control information itself is recorded can be used effectively.

FIG. 5 shows an embodiment of the format structure of the control zone of the next generation medium of the optical disk according to the present invention.
Here, the arrangement order of the areas (BA, SY, CD) is the same as that of the previous generation medium of FIG.
In this embodiment, as an example of a medium developed in a later generation, a case where the data recording density is doubled is shown.
That is, 1DCB = 0.265 μm in the previous generation medium, whereas 1DCB = 0.132 μm is shown in the subsequent generation medium in FIG.
However, in order to make the data length of each region the same so that the next generation medium can be reproduced even in the recording / reproducing apparatus for the previous generation, in this next generation medium, 1 CDB = 12 DCB = 0.132 × It is defined as 12.

In this case, as shown in FIG. 5, the physical address segment BA is 1064 DCB.
One control unit is 1020 DCB (= 85 CDB), and its physical data length is 1020 × 0.132 = about 135 μm, which is the same length as the previous generation medium shown in FIG.
That is, the physical data length of one control unit in the control zone is the same for the previous generation medium (FIG. 1) and the next generation medium (FIG. 5).

FIG. 6 shows an explanatory diagram of one embodiment of the format structure of the next generation medium in the optical disc of the present invention.
Here, in the data zone 20 and the test zone 13, it is shown that the physical data length of one data segment is 70 μm (= 532 DCB). This is half the length of the previous generation medium in FIG. 4 and indicates that the recording density is doubled.
On the other hand, the physical length of each control unit in the control zone 12 is 135 μm as described above, which is the same as the previous generation medium of FIG.
Note that the physical length of the physical address segment BA is the same as that in FIG. 4, but is composed of two areas in order to increase the density twice.

  As described above, the format structure of the control zone is defined, and the physical length of each control unit of the control zone is made constant, so even when the previous generation medium is inserted into the recording / reproducing device for the next generation, Control data recorded in the control zone can be reproduced, and even when a later generation medium is inserted into a previous generation recording / reproducing apparatus, a sufficiently large reproduction signal can be obtained from wobble format information. Control data can be read accurately.

Since the control data area has a density and structure that does not depend on the generation, when the previous generation medium is inserted into the recording / reproducing apparatus for the subsequent generation, the recognition that the previous generation medium has been inserted can be speeded up.
Furthermore, when a later-generation medium is inserted into a previous-generation recording / reproducing apparatus, user data on the medium cannot be reproduced, but since control information in the control zone can be reproduced, the time required for medium recognition is reduced, The medium recognition that the inserted medium is a later generation medium can be made faster than before.

As the recording / reproducing apparatus for recording / reproducing with respect to the optical disc of the present invention, an apparatus having a circuit configuration for realizing the push-pull signal detection method shown in FIG. 16 can be used.
When the control unit area of the optical disk of the present invention is formed by wobble, the control information can be reproduced by detecting the push-pull signal (I ₁ -I ₂ ).
That is, the push-pull signal (I ₁ -I ₂ ) is input to the comparator 54, compared with a predetermined slice level, and converted into a binary signal.
This binarized signal corresponds to the information recorded in the synchronization area (SYNC) formed by wobble and the control data area (CD).
The synchronization detection circuit 55 detects a synchronization signal (SYNC) from the binarized signal.
Thereafter, the bi-phase demodulation circuit 56 bi-phase demodulates the phase-synchronized push-pull signal using this synchronization signal (SYNC) as a trigger, and extracts control information recorded in the control data area.
When the control unit area is formed of pits, the control information can be reproduced by detecting the SUM output signal (I ₁ + I ₂ ).

The block configuration shown in FIG. 16 corresponds to a detection unit that detects control information. Although not shown, the part that receives the output signal of the biphase circuit 56 and recognizes the medium corresponds to the medium recognition unit.
The medium recognizing unit confirms the contents of the control information (units 0, 1, and 2 in FIG. 3) detected by the biphase demodulation, for example, collates the contents of the standard version and medium type, and the inserted optical disk It recognizes (determines) whether the device itself is a medium that can be recorded and reproduced.
The medium recognition unit can be realized by a microcomputer including a CPU, a ROM, a RAM, an I / O controller, and the like.

<Example 2>
Here, an embodiment of a land recording medium for recording information only on a land will be described.
FIG. 7 shows an explanatory diagram of an embodiment of the format structure of the previous generation medium of the land recording system in the optical disc of the present invention.
Here, the data structure of each zone and the physical data length of each area are the same as those shown in FIG.
That is, the control zone is composed of a synchronization area (SYNC) and a control data area, and is formed of wobbles and has no clock information such as the clock mark C1.
Further, the beam spot of the recording / reproducing apparatus for the previous generation made for reproducing the previous generation medium is large enough not to receive interference when reading information on the adjacent land as shown in FIG. (Diameter) is used.

FIG. 8 is an explanatory diagram showing an embodiment of the format structure of the next generation medium of the land recording system in the optical disk of the present invention.
Here, the data structure of each zone and the physical data length of each area are the same as those shown in FIG. However, in a medium in which only the land is recorded and the distance between adjacent lands is designed to be narrower than the diameter of the beam spot, the reproduction signal is read from the two adjacent lands when reproducing the control zone information. Therefore, the control data cannot be read accurately due to signal interference.

Therefore, in such a so-called narrow track medium, as shown in FIG. 8, it is preferable that the control information is recorded in advance only on the even tracks and the control information is not recorded on the odd tracks.
In this case, the control information is formed in an even track in the wobble format, and the odd track is a straight area in which no wobble is formed.
Conversely, the area for recording the control information may be an odd track, and the even track may be a straight area where no information is recorded.

Also in the second embodiment, as in the first embodiment, the control unit having a constant data length is formed in the synchronization area and the control data area without providing a clock mark in the control zone. The player can recognize at high speed that the previous generation medium has been inserted.
Further, even when a next generation medium is inserted into the previous generation recording / reproducing apparatus, it is possible to recognize the medium as having been inserted. In addition, since medium recognition of this next-generation medium can be performed at high speed, it is possible to prompt the user to notice that the medium has been incorrectly inserted, and to improve the usage rate of the user. Can do.

In the optical disk of this invention, it is explanatory drawing of one Example of the format structure of a control zone. It is explanatory drawing of the structural example of the control zone of the optical disk of this invention. It is explanatory drawing of the content of the concrete control information recorded on the control data area | region of this invention. In the optical disk of this invention, it is explanatory drawing of one Example of the format structure of a previous generation medium. In the optical disk of this invention, it is explanatory drawing of one Example of the format structure of the control zone of a next generation medium. In the optical disc of this invention, it is explanatory drawing of one Example of the format structure of a next generation medium. FIG. 4 is an explanatory diagram of an example of a format structure of a previous generation medium of a land recording system in the optical disc of the present invention. In the optical disc of this invention, it is explanatory drawing of one Example of the format structure of the next generation medium of a land recording system. It is a schematic block diagram of one Example of the format structure of the conventional optical disk. It is explanatory drawing of the block content of the format structure of the conventional optical disk. It is explanatory drawing of the data structure per track of the conventional optical disk. It is explanatory drawing of the data structure of one data segment in the conventional optical disk. In the conventional optical disc, it is explanatory drawing of the data structure of one track | truck in a control zone. It is explanatory drawing of the data structure of one control segment of the conventional optical disk. It is explanatory drawing of a biphase modulation rule. It is explanatory drawing of the detection of the control data by a push pull signal detection method. It is a comparison figure of the data structure of the data segment of the conventional two generations of optical disks. It is explanatory drawing of the wobble length of the conventional previous generation medium and a next generation medium. FIG. 10 is an explanatory diagram of a relationship between a pit length and a data bit length when a pit is used as preformat data in a conventional optical disc.

Explanation of symbols

10 Lead-in zone 11 Buffer zone 12 Control zone 13 Test zone 20 User data zone 30 Lead-out zone 31 Test zone 32 Control zone 33 Buffer zone BA Physical address segment CD Control data area SY Synchronization area (SYNC)

Claims (8)

An area in which clock information is fixedly recorded in advance at regular intervals, and includes a user data zone in which user information can be recorded and reproduced, and a control zone in which control information for specifying a medium is recorded. An optical disc having a track structure formed concentrically,
One track in the control zone is composed of one physical address segment area and a plurality of control unit areas, and each control unit area reproduces control information and its control information without including clock information. An optical disc characterized in that it is an area in which synchronization information for recording is fixedly recorded in advance.   The control information includes at least generation specifying information, medium type and error check data, and a set of control information is divided and recorded in a plurality of control unit areas, and the same control is recorded in one track of the control zone. 2. The optical disk according to claim 1, wherein information is repeatedly arranged.   The information formed in each control unit area is fixedly recorded in advance by a wobble formed by making the wall surface of the groove separating each track into a meandering shape, or has a predetermined data length on each track 2. The optical disk according to claim 1, wherein the optical disk is fixedly recorded in advance by pits formed in an uneven shape.   The physical data length of each control unit area is the same as the physical data length of the control unit area designed during the development of the previous generation, even if the unit recording length of data recorded in the user data zone is changed. The optical disc according to claim 1, wherein the synchronization information and the control information are repeatedly fixedly recorded in the control unit area.   5. The optical disc according to claim 1, wherein the user information is recorded only on one of a land portion or a guide groove separated by a guide groove formed in a spiral shape or a concentric shape.   5. The optical disc according to claim 1, wherein the user information is recorded in both a guide groove formed in a spiral shape or a concentric shape and a land portion separated by the guide groove.   7. A recording / reproducing apparatus for recording / reproducing user information on / from the optical disc according to claim 1.   A detection unit that detects control information included in the control zone of the optical disk according to any one of claims 1 to 6, and the optical disk records and reproduces user information from the detected control information. The recording / reproducing apparatus provided with the medium recognition part which recognizes whether it is a possible medium.

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