JPH06150566A - Disk-shaped information recording medium - Google Patents

Abstract

PURPOSE:To provide the disk-shaped information recording medium capable of increasing a storage capacity. CONSTITUTION:This recording medium has plural tracks which are concentrically or spirally formed. The plural tracks are divided to plural zones which are formatted in such sector disposition that the number of the sectors in one track increases nearer the outer zones from the inner side. The sector length of the innermost peripheral track of the zones exclusive of the first zone from the inner side is determined on the basis of the mark length smaller than the mark length of the innermost peripheral track of the first zone from the above- mentioned inner side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc-shaped information recording medium formatted in a sector arrangement such that the number of sectors in one track increases from an inner zone including a plurality of tracks to an outer zone. is there.

[0002]

2. Description of the Related Art Various recording formats have been proposed in order to obtain a large storage capacity and to record information at a target address and reproduce it with high reliability.

As a method of arranging the sectors, several methods have been proposed in correspondence with the speed control method of the spindle motor. FIG. 1 is an explanatory diagram showing a conventional typical recording format and a sector arrangement method. As shown in the figure, C
3 shows three systems of LV, CAV and MCAV.

The CLV (Constant Linear Velocit) shown in the figure
The y) method is the method that can maximize the storage capacity of the disc, and the linear velocity of the track for recording and reproducing is constant anywhere on the disc by controlling the rotation motor so that the rotation speed is inversely proportional to the track radius. Are controlled.

For this reason, assuming that sectors of a fixed length are continuously formed from the inside to the outside on a spiral track, data can be recorded in synchronization with a fixed clock. Therefore, when the data recorded by this method is reproduced, the data having a constant frequency is reproduced.

Further, this system has an advantage that the recording / reproducing conditions (for example, recording laser power) may be almost the same at any position on the disc.

Next, CAV (Constant Angular Velocit)
The y) method is a method in which the rotation of the spindle motor and the recording / reproducing frequency are constant, and has the advantage that the circuit system of the recording / reproducing device is simple and the rotating motor becomes compact.

However, since the storage capacity per track is determined by the number of recordable marks on the innermost circumference of the disc recording area, there is a drawback that the total storage capacity becomes small.

For this reason, the MCAV (Modified CAV) system takes advantage of the ease of rotation control of the CAV system and improves the disadvantage that the storage capacity is smaller than that of the CLV system. That is, this method is a method in which the number of sectors in one track is increased stepwise for each zone from the inner circumference to the outer circumference, and is characterized in that the recording frequency becomes higher toward the outer circumference. Although the track is formed in a spiral shape in the example of FIG. 1, the track may be formed in a concentric shape.

By the way, a conventional example of the format of a magneto-optical disk manufactured by adopting the MCAV system is shown in Table 1.
Shown in.

[0011]

[Table 1]

In the conventional example shown in Table 1, the disk and format were set to the following conditions.

Data area Radius 30 to 60 mm Track pitch 1.5 μm Number of bytes in one sector 1360 bytes Number of user data bytes 1024 bytes Modulation method (2,7) Recording between marks

As can be seen from Table 1, the width of each zone is uniform and the number of tracks in each zone is the same.
The minimum sector length in Table 1 is the length of one sector in the innermost track of each zone, and the minimum mark length is the mark length of the innermost track of each zone.

Further, the division of the zone is performed from the track length L _n1 of the innermost track in the zone to the track length L
_nn is the length S ₁₁ of one sector in the innermost track of the first zone (zone 0 in Table 1) from the inside of the disc.
The zone is changing when the number increases. That is,
The zone is changed when (1) is satisfied. L _nn = L _n1 + S ₁₁ (1)

Further, as can be seen from the comparison of the sector lengths in Table 1, in the conventional MCAV system, the minimum sector length S _n1 of each zone is the same for all zones.

[0017]

The MCAV system uses CL
Compared with the V method, the rotation control is easier, and the storage capacity can be increased compared with the CAV method.
This is a useful method. However, it is expected that the demand for increasing the storage capacity in the MCAV system will further increase.

Therefore, an object of the present invention is to obtain a disk-shaped recording medium capable of increasing the storage capacity.

[0019]

As described above, in the format of Table 1, the minimum sector length of each zone is the same for all zones. From a different point of view, it can be considered that the minimum sector length of each zone is equal to the one sector length of the innermost track of the first zone from the inside of the disc. The inventor came to the present invention by paying attention to this point and changing the idea.

The invention according to claim 1 has a plurality of tracks formed concentrically or spirally, and divides the plurality of tracks into a plurality of zones, and the number of sectors in one track is from the inner side to the outer side. In a disk-shaped information recording medium formatted with a sector arrangement that increases as the number of sectors increases, the sector length of the innermost track of zones other than the first zone from the inside is the innermost zone of the first zone from the inside. It is determined based on a mark length smaller than the track mark length.

[0021] According to a second aspect of the invention, in the disc-shaped information recording medium according to the first aspect, the sector length of the innermost track of the first zone from the inside is:
The sector length is equal to or longer than the minimum mark length that can be formed, and the maximum number of sectors is obtained with respect to the track length of the innermost track.

[0022]

In the present invention, in the MCAV disc-shaped information recording medium, the sector length of the innermost track of the zones other than the first zone from the inside is 1 from the inside.
It is determined based on a mark length smaller than the mark length of the innermost track of the second zone.

Here, how to obtain the length S ₁₁ of one sector in the innermost track of the first zone from the inside will be described.

Each of them is set as follows and the following equation (2)
Ask by.・ Minimum sector length based on the minimum mark length that can be formed =
S ・ Track length of innermost track of the first zone from the inner side = L ₁₁・ Number of sectors in one track of the first zone from the inner side =
N

L ₁₁ / S = N (2)

However, since the number of sectors N is an integer, S is changed so that N becomes an integer, and S is changed so that N becomes an integer.
Becomes the length S ₁₁ of one sector in the innermost track of the first zone from the inside. To change S, the number of bytes in the sector may be changed or the mark length may be changed.

In order to maintain compatibility, it is preferable to change the mark length rather than changing the number of bytes in the sector. The mark length cannot be made smaller than the minimum mark length that can be formed, so the mark length is changed to be larger. At this time, S also becomes large. Therefore, S ₁₁ is larger than S. Here, the mark length when the sector length is S ₁₁ is M _11, and the minimum mark length that can be formed is M.

In the present invention, the sector length of the innermost track of the zones other than the first zone from the inner side is determined on the basis of the mark length smaller than M ₁₁ in S ₁₁ obtained as described above.

Specifically, conventionally, it was necessary to change the minimum sector length S based on the minimum mark length M that can be formed in the equation (2) so that the number of sectors N becomes an integer. Then, this is done only in the first zone from the inside, and the sector length in the other zones is the mark length M ₁₁ in S ₁₁ .
Is set as a standard.

That is, the length S ₁₁ of one sector in the innermost track of the first zone from the inside is used as a reference for the minimum mark length M that can be formed in the innermost track length L ₁₁ . Maximum sector number N with minimum sector length S or more
(N is an integer) is the minimum sector length S ₁₁ .

[0031]

EXAMPLES In the examples of the present invention, the disk and format were set under the following conditions. Incidentally, this condition is the same as that of the conventional example shown in Table 1 above.

Data area Radius 30 to 60 mm Track pitch 1.5 μm Number of bytes in one sector 1360 bytes Number of user data bytes 1024 bytes Modulation method (2,7) Recording between marks

Under the above conditions, the sector length based on the mark length smaller than the mark length (0.76 μm) of the innermost track of the first zone from the inside of the disc is divided into zones and 1 from the inside of the disc. Table 2 shows the format when the sector length of the innermost track in each zone except the second zone is used as a reference.

[0034]

[Table 2]

As can be seen from Table 2, in this embodiment, the minimum mark length of the zones other than the first zone from the inside of the disc (the mark length of the innermost track of the zone) is 0.73 μm.
m. The zone cut divides the, S ₁₁ the mark length (1 sector length of the innermost track of the first zone from the inside of the disk) of the formula (1) shown in the prior art
The zone is changed when the equation replaced with the sector length (0.0106 m) based on 0.73 μm is satisfied. As a result, the number of zones is larger than in the past.

From Table 2, the storage capacity of the format using the method of the present invention is 536.9 Mbytes, and the storage capacity of the format using the conventional method shown in Table 1 above is 512.2 Mbytes. is there. Therefore, by using the present invention, the storage capacity can be increased by 4.8%.

Further, as can be seen from Table 2 and Table 1 described above, the disc of the present invention is different only in the division of the zones of the conventional disc, and other configurations (data area, track pitch, etc.) No need to change. Further, regarding the drive device, there is also an advantage that it is not necessary to change the hardware of the electric circuit or the like only by changing the software of the sector ID table in which the zone is switched.

[0038]

As described above, the present invention has an effect that it is possible to obtain a disc-shaped information recording medium capable of efficiently dividing a zone and increasing the recording capacity.

Further, in the present invention, only the division of zones of the conventional disk is changed, and there is no need to change other configurations (data area, track pitch, etc.). In addition, regarding the drive device, simply by changing the software of the sector ID table that switches the zone,
There is no need to change hardware such as electric circuits. Therefore,
It has the effect that it can be easily realized from conventional products.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a conventional typical recording format and a sector arrangement method.

Claims (2)

[Claims] 1. A plurality of tracks formed concentrically or spirally, the plurality of tracks are divided into a plurality of zones, and the number of sectors in one track increases from the inner zone to the outer zone. In the disc-shaped information recording medium formatted with the sector arrangement, the sector length of the innermost track of zones other than the first zone from the inside is smaller than the mark length of the innermost track of the first zone from the inside. A disc-shaped information recording medium characterized by being defined based on a length. 2. The disc-shaped information recording medium according to claim 1, wherein the sector length of the innermost track of the first zone from the inside is not less than the sector length based on the minimum mark length that can be formed. A disk-shaped information recording medium, wherein the sector length is such that the maximum number of sectors can be obtained with respect to the track length of the innermost track.