JP3430104B2 - Optical disc and master disc mastering method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a master disc mastering method for an optical disc having both a read-only area and a rewritable area, and both areas having different track formats.

[0002]

2. Description of the Related Art When an optical disk has both a read-only area and a rewritable area, the problem is how to set the boundary portion. At the boundary between the read-only area and the rewritable area, if both areas are too close to each other, data will be confused, while if both areas are separated, the utilization efficiency of the optical disk recording surface will be reduced.

As a conventional example, for example, JP-A-62-18
Japanese Patent No. 4630 discloses an example in which both a read-only area and a rewritable area are provided on an optical disc as shown in FIG. In this example, both the read-only area and the rewritable area are provided on the rewritable recording film, and the CAV (Consta
The recording sectors are arranged in a sector layout of the nt Angular Velocity) system. The sectors in both areas have the same sector format in which the sector ID is added by pre-formatting, and the boundaries between both areas are continuous. The difference is that in the rewritable area, the data recording area is on a flat groove, whereas in the read-only area, preformatted data has pits on the land surface, that is, pits with intermittent grooves. The points are shown in columns.

Further, Japanese Patent Application Laid-Open No. 62-285232 discloses an example in which a guard area is provided at the boundary between the read-only area and the rewritable area provided on the optical disk as shown in FIG. This example is described in JP-A-62-18463.
At the boundary between the read-only area and the rewritable area having the same shape as shown in Japanese Patent Publication No. 0, the areas called guard areas are set on both sides to protect the data by not using it for actual data recording / reproduction. The technology is disclosed.

In both of the examples, the groove in the rewritable area and the pit in the read-only area have substantially the same width, and the same beam can be used for cutting when mastering an optical disk master. Therefore, no special operation is required at the boundary between the rewritable area and the reproduction-only area, and the groove and pit can be formed with a predetermined size by simply blinking the power of the cutting beam.

[0006]

SUMMARY OF THE INVENTION According to the present invention, in an optical disc having both a read-only area and a rewritable area, and both areas having different track formats, the track arrangement condition at the boundary portion thereof is defined. To provide a new optical disc that prevents confusion of data in both regions and that prevents the use efficiency of the optical disc recording surface from being lowered by arranging both regions as close as possible. The aim is to get a way to master the master.

It is another object of the present invention to reduce the manufacturing cost and improve the master disk manufacturing yield by relaxing the adjustment setting accuracy of the mastering device when mastering an optical disk master.

It is another object of the present invention to provide a method of mastering a master for providing an optical disc in which discontinuity of sector addresses does not occur at the boundary between the read-only area and the rewritable area.

[0009]

An optical disk according to claim 1
Click has both a reproduction-only area and the rewritable area, chromatic Then together the track format of the two regions have different
In addition, the read-only area is the same for different types of optical disks.
Includes a control data area with one format
In the optical disc , the last sector of the read-only area
The beginning of the first sector of the end and the rewritable area in contact on the same radial line are arranged, when the track pitch of the track pitch of the read only area the rewritable region is different
Come, greater or the track center spacing of the first track of the last track and the rewritable area of the reproduction-only area
If you arrange it so that it is more than twice the track pitch of one
Together, characterized in that the address of the head sector address and the rewritable area of the end sector of the read-only region is numbered so as to continue communication.

A master disc mastering method for an optical disc according to a third aspect of the present invention has both a read-only area and a rewritable area, a track consisting of recording pits is formed in the read-only area, and a groove track is provided in the rewritable area. Both areas have different track formats by forming
In addition, the read-only area has different types of optical disks.
But the control data area with the same format
A method for mastering an optical disc master including an area ,
The track pitch of the read-only area and the track pitch of the rewritable area are different from each other so that the end portions or start edges of both tracks at the boundary between the read-only area and the rewritable area are in contact with each other on the same radial line. when, as the track center spacing at the boundary portion of the track of the track and the rewritable area of the reproduction only area is more than twice the larger one track pitch
Formed on the address and the address of the rewritable area of the playback only area is characterized by being numbered so as to be continuous at the boundary.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the drawings.

Embodiment 1. FIG. 1 shows an area layout of a disk surface of an optical disk to which the present invention is applied. This is an optical disc having both a read-only area and a rewritable area, and both areas having different track formats. A read-only area is arranged on the inner circumference side of the disc, and a rewritable area is arranged on the outer circumference side. Recording sectors are arranged in a CAV sector layout in both areas. The present invention has a so-called ZCAV (Zoned CAV) format format in which at least one of the read-only area and the rewritable area is divided into a plurality of zones in the radial direction to make the recording density in each zone substantially constant. Although it can be applied to optical discs in general, the following description will be given by taking the CAV method as an example for simplification of the description, considering that the present invention relates to the shape of the boundary between the read-only area and the rewritable area. Each sector has an ID area for accommodating a sector address or the like at the head portion, and is followed by a data area for accommodating rewritable data or reproduction-only data. In the example shown in FIG. 1, one track of the reproduction-only area is composed of, for example, 16 sectors, and one track of the rewritable area is composed of, for example, 12 sectors. Since the number of sectors per track is different, it goes without saying that the ID area of the reproduction-only area and the ID of the rewritable area at the boundary between the reproduction-only area and the rewritable area.
Some areas will not line up next to each other.

FIG. 2 shows an enlarged part of the boundary portion of such an optical disk. The track pitch of the read-only area and the track pitch of the rewritable area are almost the same. At this time, let us consider a case where a so-called land / groove recording method is used as a recording method of the rewritable area, in which both the groove as a guide groove and the land corresponding to the groove are used as recording tracks. Information is represented on the recording film in the form of recording marks. This is shown in the upper half of FIG. In order to record both the land and the groove with the same performance, the land width and the groove width are generally set to be almost the same. When a phase change material such as GeSbTe is used for the recording film, the recording mark is represented by the difference in reflectance.
When a magneto-optical material such as o is used, the recording mark is represented by the direction of magnetization perpendicular to the recording surface. In any case, the presence of the recording mark is detected by the change of the light amount of the reflected light or the change of the polarization component, and the recorded information is reproduced.

The reproduction-only area is a CD (Compact D
The same recording as that used for isc) is performed by the concave pit row. This is shown in the lower half of FIG. The presence of recording pits is detected by the change in the amount of reflected light,
The recorded information is reproduced. The recording pit is formed together with the groove in the rewritable area when mastering the optical disc master. The track pitch is the center interval between adjacent pit rows. Therefore, when the track pitch of the read-only area and the track pitch of the rewritable area are set to be substantially the same, the recording pit width is about half the groove width. With regard to the pit width, if this is made too large,
The signal quality is deteriorated due to an increase in so-called crosstalk, in which signals from adjacent tracks are mixed during reproduction. On the other hand, if it is too small, the reproduction signal level will be insufficient, and cutting of the master and molding of the disk will be difficult.

The diameter d of the spot of the light beam used for recording / reproducing on / from the optical disk is determined to be approximately d = (λ / NA) from the light wavelength λ and the numerical aperture NA of the condenser lens. λ = 63
When 5 nm and NA = 0.6, d = 1.06 μm. If the track pitch is narrowed to the crosstalk allowable limit in order to increase the capacity of the disk, for example, 0.74 μm, the light spot will reach a part of adjacent tracks on both sides of the target track. In the read-only area, the left and right ends of the spot are 0.16 μm each, and are projected to the adjacent tracks. Recording pit width 0.4 μm
Then, the recording pit is 0.2μ from the center of the recording track.
In other words, the recording pits exist in the area within m, that is, the recording pits exist only in the areas near the center of 0.17 μm or more from both ends of the recording track. Therefore, the skirts of the spots of 0.16 μm each protruding to the tracks on the left and right sides do not have to hang on the recording pits of the adjacent tracks. When the groove width of the groove track in the rewritable area is 0.74 μm, the left and right skirts of the spot are each 0.16 μm apart and protrude to the adjacent land track. Here, if recording is performed by limiting the recording mark width to some extent, or if a method of making the groove depth about 1/6 of the light wavelength, which is known as a crosstalk canceling condition, is adopted. Crosstalk can be canceled. The same applies to land trucks.

However, in order to apply the crosstalk cancel condition, there must be lands on both sides for a groove track and grooves on both sides for a land track.
Since the land track at the boundary between the read-only area and the rewritable area cannot sufficiently cancel the crosstalk, it is not suitable for use as an information recording track. The land track included in the track interval at the boundary in the center of FIG. 2 indicates this unusable portion. FIG. 2 shows a case where the reproduction-only area and the rewritable area are arranged closest to each other. If the lower part of the figure is the inner circumference of the disc and the upper part is the outer circumference of the disc, the distance between the track at the outer edge of the read-only area and the track at the inner edge of the rewritable area is
As shown in the track spacing at the boundary, it is twice the track pitch of other parts. This distance is 1.48 μm when the track pitch is 0.74 μm.

Now, consider a master mastering process when manufacturing such an optical disk. As described above, the recording pits and the grooves are continuously cut during mastering of the master. When the groove width and the pit width are different,
The light beam for cutting needs to be set thin when cutting the pit and thick when cutting the groove. Since the cutting device adjusts the optical beam shape by adjusting the optical system with extremely high precision in order to precisely cut pits and grooves, it is difficult to change the setting of the optical system during cutting. Therefore,
When trying to cut pits or grooves of two different widths, it is convenient to use two light beams with the beam diameter adjusted and set optimally to cut the pits or grooves of each width. . The problem at this time is the accuracy of the alignment of the two beams. As described above, in order to adjust the track interval at the boundary between the track on the outer edge of the read-only area and the track on the inner edge of the rewritable area to 1.48 μm, the two beams are aligned with sub-micron accuracy. There is a need to. This adjustment, or the maintenance of its accuracy, generally requires a lot of work each time it is manufactured. This causes a reduction in yield of the cut master and an increase in manufacturing cost.

FIG. 3 shows an embodiment in which the track interval at the boundary is enlarged as a means for relaxing the precision of alignment of the two beams. In this figure, two unused tracks are provided at the boundary. It is advisable to increase the allowable width of the track interval itself at the boundary after adopting such a configuration. In this example, the positional accuracy can be up to 0.74 μm for about one track. If the track interval at the boundary is further increased, the allowable width is increased accordingly. However, since the utilization efficiency of the recording surface of the optical disk is reduced by the amount of expansion of the track interval at the boundary portion, the upper limit is set to a range where there is no problem in beam alignment accuracy. 2 above for mastering master
Although a cutting device having two beams is assumed, the optical system can be variously configured even with the same two-beam device as is known. When setting the track layout of the optical disc as described in this embodiment, it is preferable to loosely define the beam position accuracy so that the optical system can be configured as freely as possible.

When considering the maximum width of the track interval at the boundary, another point to be considered is the seek operation in the radial direction in the optical disk device that drives this optical disk.
It is necessary to estimate or measure the amount of movement of the light spot during the seek operation in the radial direction. It is common to count the number of track crossings from the waveform of the track crossing signal to obtain this movement amount. At this time, if there is a boundary where no track exists, an error occurs in the track crossing count number. When the crossing signal waveform suddenly disappears in the track crossing signal, it is often judged that the signal is crushed due to a medium defect or dust, and the crossing count number is often corrected. In this case, the track crossing count may be erroneously corrected at the boundary that forms the mirror surface, so it is necessary to ensure that the track interval at the boundary falls within the allowable error range of the crossing count. There is. For this purpose, it is desirable that the error can be recovered by one micro seek even if the count is wrong. Here, if the track count error is 20 or less, the purpose can be achieved in almost all optical disk devices. Normally, it takes about 1ms to jump one track.
ec takes about 20mse to jump 20
c takes time. This time of about 20 msec corresponds to the rotation waiting of one rotation of the disk when the disk rotation speed is 50 Hz. If the time required to recover the track crossing number miscount is less than or equal to this rotation waiting time, it can be set within the allowable range.

In summary, the track interval at the boundary, which is the interval between the track centers of the last track of the reproduction-only area and the first track of the rewritable area, is within a predetermined range of not less than 2 times and not more than 20 times the track pitch. This means that they should be arranged so that any value within the range is acceptable.
For example, in the above example in which the track pitch is 0.74 μm, the track interval at the boundary is set to 2 of the track pitch.
If the distance is doubled to 20 times, the distance becomes 1.48 μm to 1
The allowable range is 4.8 μm. That is, the relative position of the two beams of the master cutting device is set to 8.14 +/− 6.6.
The setting error may be up to 6.66 μm. This is a condition that adjustment accuracy is sufficiently loose.
This width may be further limited within a range that fits the above purpose. For example, in the same example in which the track pitch is 0.74 μm, if the track interval at the boundary portion is 2 to 8 times the track pitch, the allowable range is 1.48 μm to 5.92 μm in distance. That is, the relative position of the two beams of the master cutting device is 3.7 +/- 2.2.
It may be set to 2 μm, and a setting error of up to 2.22 μm can be allowed. This is also a sufficient condition for adjustment accuracy.

Embodiment 2. An example in which the present invention is applied to a specific format of each sector of the reproduction-only area and the rewritable area will be shown. It is assumed that the entire optical disc has the track layout shown in FIG. FIG. 4 shows a sector shape near the boundary. The lower side of FIG. 4 corresponds to the inner peripheral side of the disc, and the track is shown in FIG.
From left to right inside. In this figure, a portion of one track where the end of each track and the beginning of the next track are connected is mainly shown. The sector of the read-only area has an ID area at the beginning and a data area in which read-only data is recorded behind the ID area. The recording is the pit string recording described in the first embodiment. Since the recording tracks run on one spiral, one disk
When you go around, you will come to the outside position. The radius line shown in FIG. 4 is a radius in a certain direction assuming only one on the disc, and the heads of the recording tracks are arranged on this radius.
Of course, the head portion of the head sector of each track and its ID area are also arranged.

The structure of the tracks and sectors of the rewritable area is as follows: Japanese Patent Application No. 8-687 filed by the present inventors.
According to the single spiral land / group recording format disclosed in No. 33, etc. In this format,
Similar to the normal land / groove recording described in the first embodiment, data is recorded on both the land track and the groove track, but there are two features. The first point is
It is how to connect the groove track and the land track. Groove tracks and land tracks are alternately connected one by one to form one spiral. In other words, when the track starts from the radius line and goes around the disk once, the groove is connected to the land and the land is connected to the groove. The second point is the arrangement of preformat signals in the ID area. The ID area is divided into two parts, which are located on the boundary line between the land track and the groove track, but when viewed with reference to the groove track, the first half part is displaced by half track pitch to the outer peripheral side, and the second half part is It is arranged with a half track pitch displacement on the inner peripheral side.
The sector address of the groove track following the track shifted by a half track pitch is stored in the latter half part, and the sector address of the land track adjacent to the outer periphery of the groove track is stored in the first half part. By doing so, the tracks in the rewritable area are connected in a spiral shape as a whole, and the sector addresses can be numbered in the order placed on the spiral.

FIG. 4 shows a case where the boundary between the reproduction-only area and the rewritable area is arranged closest to each other, as in the case shown in FIG. At the boundary between the read-only area and the rewritable area, the end of the last sector of the read-only area and the head of the first sector of the rewritable area are arranged on the same radius.
Since the head portions of the head sectors of the tracks in the read-only area and the rewritable area are aligned, even if the track interval at the boundary is the smallest, in any part of the track circumference,
There is no possibility that a part of the track in the reproduction-only area and a part of the rewritable area overlap with each other will result in a collapsed portion of the track, or the tracks will be too close to each other and data will be confused with each other.

FIG. 5 shows a case where the boundary between the reproduction-only area and the rewritable area is arranged with a certain distance, as in the case shown in FIG. As in the example of FIG. 4, the end of the last sector of the read-only area and the head of the first sector of the rewritable area are arranged in contact with the same radius line. The boundary between the read-only area and the rewritable area is a ring-shaped mirror area on the disc. This mirror area is a boundary area, and its width is set as described in the first embodiment.

FIG. 6 shows a method of assigning sector addresses to the sectors of the read-only area and the rewritable area thus arranged on the disk. Similar to FIG. 4 and FIG.
Also in FIG. 6, the lower side corresponds to the inner peripheral side of the disk, and the tracks are continuous from the left side to the right side of the drawing. When the addresses are sequentially assigned from the inner circumference side of the disc, the sector in the read-only area is assigned a younger address than the sector in the rewritable area. As shown in FIG. 6, the numbering is performed such that the sector address of the last sector of the reproduction-only area and the address of the first sector of the rewritable area are continuous. In this example, a sector address of 30,000H is assigned to the first sector of the rewritable area. The sector address of the last sector of the read-only area is set to 2FFFFH, and the sectors before the sector address are sequentially assigned young addresses. By doing so, it is possible to prevent the discontinuity of the sector addresses from occurring at the boundary between the read-only area and the rewritable area. In the example of the address numbering method, one track is composed of 17 sectors in the rewritable area, and one track is composed of 18 sectors in the reproduction-only area. In FIG. 1, one track is composed of 12 sectors in the rewritable area and one track is composed of 16 sectors in the reproduction-only area. However, the number of sectors can be appropriately set within the allowable range of the recording density. Of course, one track in both areas can be composed of the same number of sectors.

In this way, even if the boundary between the reproduction-only area and the rewritable area is physically separated by a distance corresponding to several tracks, the sector addresses indicating the logical order of the sectors are continuous. It will be. If the sector addresses are not continuous in the continuous sector address space, a problem occurs in the optical disk device that drives this optical disk. An error may occur in the calculation of the number of seek tracks at the time of access, the access time may be extended, or an attempt may be made to access a sector that does not actually exist on the disk, resulting in a device failure. In addition, the access control program for the target sector becomes complicated, and a malfunction due to a program mistake is likely to occur. It has become possible to avoid these points.

Embodiment 3. In an optical disc in which a reproduction-only area and a rewritable area are mixed, the reproduction-only area is often used as a control data area in which information regarding the format of the optical disk is stored. When the optical disk device starts the optical disk, it first accesses this track to read the parameters for servo control and signal recording / reproduction,
Set the control parameters of the device. This is to enable information recording / reproduction in an optimum state thereafter. When the capacity of optical discs increases or the number of types increases, in order to ensure the compatibility of handling one type of disc with another type of optical disc device, the control data area must be readable by all optical disc devices. It is desirable to put it. Therefore, the read-only area having the control data area has the same format on different types of optical disks, and the format is changed only in the rewritable area. For example, the track pitch and the linear recording density are increased to increase the density. Can be considered. The logical format of the sector including the ID area and the data area may be the same or different between the read-only area and the rewritable area. In the rewritable area, a data pattern for ensuring synchronization of recording signals, a buffer area for ensuring a margin for disk rotation fluctuation, and the like, which are not necessarily read-only areas, are required. By using the sector format dedicated to the read-only area, the recording capacity of the read-only area can be maximized.

7 and 8 show the case where the track pitch is different between the reproduction-only area and the rewritable area. Figure 7
In the same manner as shown in FIG. 3, shows a part of the boundary part enlarged when the boundary between the reproduction-only area and the rewritable area is arranged with a certain distance. An example in which the track pitch in the read-only area is 0.74 μm as described in the first and second embodiments, and the track pitch in the rewritable area is smaller than the track pitch in the read-only area, for example, 0.37 μm. Is. Similar to FIG. 5, FIG. 8 shows a sector shape in the vicinity of the boundary when the boundary between the reproduction-only area and the rewritable area is arranged with some distance therebetween.

In such a case, the track interval at the boundary between the reproduction-only area and the rewritable area is set to be twice the track pitch of the larger of the track pitches and 2 or more.
One method is to define the arrangement within a predetermined range included in the range of 0 times or less. By doing so, even if the track interval at the boundary is minimized, the crosstalk from the adjacent track can be suppressed within the allowable range.

This also has an advantage when the mastering process of the master is taken into consideration. Usually, when cutting the master, a light beam for cutting is sent in the radial direction while rotating the master to form recording tracks, that is, grooves and pit rows. When the track pitch is different between the read-only area and the rewritable area of the disc, it is necessary to switch the beam sending speed in the radial direction at the boundary between the two areas. Here, if the track intervals on the boundary are wider than necessary for switching the feed speed, switching can be performed while passing through this part, so cut the tracks in each area accurately at the specified track pitch. You can As described above, the track interval at the boundary between the read-only area and the rewritable area is positioned within a predetermined range of 2 times or more and 20 times or less of the larger value of the respective track pitches. If there is a margin as described above, it is possible to secure the time required for switching the feed rate.

Fourth Embodiment In the third embodiment, an example in which the read-only area has a track pitch of 0.74 μm and the track pitch is increased only in the rewritable area for higher density in an optical disc in which the read-only area and the rewritable area are mixed However, as a similar example, the track pitch of the rewritable area is set to 0.
A case of 6 μm is shown. In this case, the groove width is 0.
It is 6 μm. Here, if the pit width of the read-only area is set to 0.5 μm, which is slightly wider than approximately half the track pitch, the difference from the groove width of 0.6 μm in the rewritable area is reduced. Since the groove width is about 1.2 times the pit width, it is possible to cut with one beam depending on the performance of the master cutting device. When cutting with one beam, there is no problem with the alignment accuracy of the two beams.
I want to place the read-only area and the rewritable area as close as possible. This is because it is more advantageous for avoiding a miscount when seeking.

Even in such a case, the allowable range of the track interval at the boundary between the read-only area and the rewritable area is included in the range of not less than 2 times and not more than 20 times the larger track pitch of the respective track pitches. In the 1-beam cutting apparatus that provides the best cutting accuracy, it is possible to minimize the track interval at the boundary in the same manner as shown in FIGS. 2 and 4. it can. In this way, crosstalk from adjacent tracks can be suppressed within the allowable range, and the effect of the continuity of sector addresses can be utilized without degrading access performance.
It is of course possible to use a two-beam cutting device within the allowable range of cutting accuracy.

[0033]

Since the present invention is constructed as described above, the optical disk produced by using the master prepared by the mastering method according to the present invention has the following effects. At the boundary of the reproduction-only area and the rewritable area, by the radial spacing of the first track of the last track and the rewritable area of the reproduction-only area, defined to place more than doubled the value of the track pitch, It has become possible to avoid that the tracks in the reproduction-only area and the rewritable area are too close to each other to form a crushed portion of the tracks, or confusion of data with each other occurs .

Further, in the mastering device for mastering the master of this optical disc, it is possible to relax the setting accuracy of the relative positions of the beam for cutting the read-only area and the beam for cutting the rewritable area. The load on the adjustment for setting is reduced, and the manufacturing cost can be reduced. Alternatively, the master can be cut as long as the relative positions of the two beams can be adjusted within the predetermined range, so that the master mastering device can be more freely and easily configured. Along with this, it has become possible to improve the production yield of the master.

Further, by arranging the sector of the read-only area and the sector of the rewritable area on the same radius at the boundary between the read-only area and the rewritable area, the read-only area and the rewritable area are closest to each other. Then, when mastering is performed, it becomes possible to continue smooth tracking from the sector of the read-only area to the sector of the rewritable area without moving in the radial direction. At this time, it is also possible to avoid the occurrence of a crushed portion of the track due to the overlapping of only a part of the track of the reproduction-only area and the rewritable area.

Further, since the sector address of the reproduction-only area and the sector address of the rewritable area are consecutively numbered, a sector that does not actually exist on the disk may appear in the continuous sector address space. I was able to avoid it. As a result, in the optical disk device that drives this optical disk, it becomes easy to simplify the access control program to the target sector and to avoid malfunction due to a program error.

An optical disc having a rewritable area of a single spiral land / group recording format has a feature that the array sequence of sectors is physically and logically continuous even though it is land / group recording. Have By applying the present invention when a read-only area is additionally provided on a disc of this format, it has become possible to maintain the feature that the sector arrangement order is logically continuous.

In the future, in an optical disc that uses the reproduction-only area as a control data storage area,
When creating a disc with different track pitches in the rewritable area and the read-only area by reducing the track pitch in the rewritable area for higher capacity, tracks with different track pitches in both areas during mastering of the master disc. It has become possible to accurately secure the track pitch in each region while manufacturing the.

In the above description, the reproduction-only area is arranged on the inner circumference side, the rewritable area is arranged on the outer circumference side, and the sectors are arranged in the order from the inner circumference side to the outer circumference side. Needless to say, the purpose of is not limited to this form. The same method can be applied to an optical disc in which the rewritable area is arranged on the inner circumference side and the read-only area is arranged on the outer circumference side in an optical disc in which the sectors are arranged from the inner circumference side to the outer circumference side, and the same function and effect are obtained. Is to demonstrate. Also, in an optical disc in which sectors are arranged in an order from the outer circumference side to the inner circumference side, the read-only area is set to the outer circumference side,
The same method can be applied to various modifications such as the one in which the rewritable area is arranged on the inner peripheral side, and the same function and effect are exhibited. Furthermore, the present invention is a reproduction-only area, or
At least one of the rewritable areas is divided into a plurality of zones in the radial direction to make the recording density in each zone substantially constant,
In general optical discs having a so-called ZCAV (Zoned CAV) format, the present invention can be applied to the boundary between the read-only region and the rewritable region on the disc,
It goes without saying that the same effect is exhibited.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a region layout of an optical disc according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a track shape of the optical disc according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram of a track shape of the optical disc according to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram of sector arrangement of the optical disc according to the second embodiment of the present invention.

FIG. 5 is an explanatory diagram of sector arrangement of the optical disc according to the second embodiment of the present invention.

FIG. 6 is an explanatory diagram of a sector address numbering method for an optical disc according to a second embodiment of the present invention.

FIG. 7 is an explanatory diagram of a track shape of the optical disc according to the third embodiment of the present invention.

FIG. 8 is an explanatory diagram of sector arrangement of the optical disc according to the third embodiment of the present invention.

FIG. 9 is an explanatory diagram of a region layout of a conventional optical disc.

FIG. 10 is an explanatory diagram of a region layout of a conventional optical disc.

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-10-105977 (JP, A) JP-A-8-161749 (JP, A) JP-A-8-22640 (JP, A) JP-A-5- 159295 (JP, A) JP-A-63-298717 (JP, A) Patent 3063641 (JP, B2) Patent 3073746 (JP, B2) International Publication 97/50082 (WO, A1) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B ^7/ 00-7/013 G11B 7/24 G11B 7/30 G11B 20/12

Claims (4)

(57) [Claims] 1. A have both read only area and the rewritable area, to have a track format in which the two regions are different
In addition, the read-only area has different types of optical disks.
But the control data area with the same format
An optical disk comprising a band, the final of the reproduction-only area
And contacting the head of the first sector of the sector end and the rewritable area on <br/> same radial line disposed, the track pitch of the track pitch of the read only area the rewritable area is different
Rutoki, track center distance or large the first track of the last track and the rewritable area of the reproduction-only area
Arrange so that it is more than twice the track pitch of your choice .
Rutotomoni, optical disks that address of the head sector address and the rewritable area of the last sector of the reproduction-only area is characterized by being numbered to continue communicating. 2. The reproduction-only area or rewritable area
Of at least one of the
Characterized by making the recording density in each zone almost constant
The optical disc according to claim 1, wherein 3. A track format having both a read-only area and a rewritable area, a track consisting of recording pits being formed in the read-only area, and a groove track being formed in the rewritable area so that both areas have different track formats. Have
In addition, the read-only area has different types of optical disks.
But the control data area with the same format
A method for mastering an optical disc master including an area ,
The track pitch of the read-only area and the track pitch of the rewritable area are different from each other so that the ends or the start ends of both tracks at the boundary between the read-only area and the rewritable area are in contact with each other on the same radial line. when, as the track center spacing at the boundary portion of the track of the track and the rewritable area of the reproduction only area is more than twice the larger one track pitch
Master mastering method for an optical disc formed, the address and the address of the rewritable area of the playback only area is characterized by being numbered so as to be continuous at the boundary portion. 4. The formation of the recording pit and the glue
The formation of the track is performed using two light beams.
The optical disc master according to claim 3, wherein
Mastering method.