JPH1196559A - Disk medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk medium with which recording and/or reproducing is possible while a defective sector is compensated in real time. SOLUTION: The unit block of a logic zone consists of a user area of 252 sectors and a spare area of 4 sectors. The spare area is arranged at the last tail of the block. The respective sectors have a data quantity of 3K byte. The data quantity per unit logic zone is, therefore, about 8 megabyte. When this quantity is track converted in accordance with DVD-RAM standards, the quantity is about 200 tracks in the physical zone of the innermost periphery. Even if, therefore, a pickup body is not sought, the jump from the user area to the spare area is made possible only by the drive control of an objective lens.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk medium and, more particularly, to a disk medium for real-time recording and reproduction of audio and video information.

[0002]

2. Description of the Related Art DVD-RAM (Digital Video Disc-
FIG. 2 is a conceptual view of the appearance of a random access memory.
Recording tracks are formed spirally on the disk. The disk is divided into 24 physical zones. In the figure, 11 indicates a physical zone. Data is recorded in each physical zone so that each speed is constant. Also, the angular velocity differs for each physical zone. The inner peripheral portion has a large angular velocity, and the closer to the outer peripheral portion, the smaller the angular velocity. This effectively increases the recording capacity of the disc.

FIG. 3 shows a logical format of data recorded in each physical zone. As shown, the unit block is divided into a user area and a spare area. Normally, data is recorded in the user area sequentially from the head (logical address “0”) in sector units. Here, if there is no defective sector in the user area, normally, no data is recorded in the spare area. The spare area is used as a spare sector when a defective sector exists in the user area. That is, only when a defective sector exists in the user area, the spare area is used to compensate for the defective sector.

[0004] The unit block composed of the user area and the spare area is arranged over one physical zone. Such a physical zone has around 2500 recording tracks. Therefore, when the spare area is located at the end as shown in FIG. 7, a gap of about 2500 tracks exists between the user area and the spare area at the maximum.

[0005]

In order to compensate for the defective sector, a slipping replacement is required.
cement: SR and linear replacement
lacement (LR) is used. Among them, SR is a method of skipping defective sectors and recording data in the next sector in order. In this case, the spare area is recorded in such a manner that the trailing sector is shifted by the number of defective sectors in the recording data sequence. On the other hand, LR is a method of replacing a defective sector with a spare area. That is, data to be recorded in the defective sector is recorded in the spare area.

[0006] Among the compensation methods, the SR skips defective sectors and records data in the next sector in order, and thus has the advantage that recording and reproduction in real time can be easily performed. Therefore, usually, at the time of the first data recording on the disc, defect compensation is performed by employing the SR while referring to the defective sector in the table of contents information. However, in the case where new data is rewritten after data is once recorded, in the SR, all the sectors after the defective sector must be appropriately advanced in the trailing direction and re-recorded. Therefore, in such a case, a method is employed in which data of a defective sector is recorded in a spare area by LR.

As described above, in the conventional disk,
Defective sectors are compensated for by appropriately using SR and LR. However, as described above, since there is a gap of about 2500 tracks between the user area and the spare area at the maximum, when performing data recording / reproduction by LR, the seek operation is performed while moving the pickup itself in the disk radial direction. Must be done. Such a seek operation involves a large time loss in recording and reproducing data. Therefore, a large-capacity memory is required to perform recording and reproduction in real time.

Therefore, the present invention solves such a problem,
It is an object to provide a disk medium which can record and / or reproduce in real time.

[0009]

In order to achieve the above object,
The present invention has the following features. 2. The disk medium according to claim 1, wherein a logical format including a user area and a spare area is arranged on a spiral and / or concentric track to form a unit logical zone, and a radial track between the user area and the spare area. The number is set within the beam deflection scanning range of the pickup. According to this feature, for example, a jump from the user area to the spare area can be performed only by beam deflection scanning by driving the objective lens without performing a seek operation for transferring the pickup body. For this reason, even when the LR method is adopted, the time loss of data recording / reproducing with respect to a defective sector can be remarkably limited, so that real-time data recording / reproducing can be performed.

According to a second aspect of the present invention, in the first aspect, when the number of radial tracks between the user area and the spare area is different at a position on the disk, the maximum number of the radial tracks is changed by the beam deflection of the pickup. It is characterized in that it is set within the scanning range. According to such a feature, the effect of claim 1 can be obtained at an arbitrary position on the disk.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a data format of a logical zone according to the embodiment. The unit block of a logical zone is
It consists of a user area of 252 sectors and a spare area of 4 sectors. The spare area is located at the end of the block. Each sector has a data amount of 32 Kbytes. Therefore, the data amount per unit logical zone is about 8
It will be megabytes. When this is converted into a track based on the DVD-RAM standard, it is approximately 2 in the innermost physical zone.
00 tracks.

Here, the recording track on the disk is usually slightly eccentric in the shape of an ellipse, so that the objective lens is displaced from the neutral position by several tens of tracks. Therefore, in order to make the beam jump from the user area to the spare area only by controlling the driving of the objective lens, the beam deflection scanning range ± N by the objective lens, the number of tracks T by the logical zone, and the number of displacements of the objective lens H by the eccentricity are required. , A relationship of N ≧ T + H must be established. Therefore, in the disk according to the present embodiment, if sector defect compensation is performed by LR only by driving the objective lens, it is necessary to set the beam deflection scanning range N of the pickup to N ≧ 200 + H.

Conversely, when the beam deflection scanning range N of the pickup is given, the data capacity of the logical zone may be set so as to satisfy T ≦ N−H. For example, assuming that the number of displacements of the objective lens due to track eccentricity is about 30 tracks, T ≦ N−30 tracks,
Set the data capacity of the logical zone. Such data capacity can be easily calculated based on factors set in the standard, such as angular velocity and data transfer rate.

On the disk, a plurality of the above logical zones are arranged for each physical zone. According to the present embodiment, the number of tracks in the unit logical zone is about 200 tracks, and the number of tracks in each physical zone is about 2500, so that about 22 logical zones are allocated to each physical zone. . Of course, if the disc does not employ the zone CAV like a DVD-RAM, the logical zone may be arranged over the entire disc.

Although the embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to such embodiments. For example, the spare area may be arranged at the center instead of at the end of the block. In this case, user areas are arranged before and after the spare area, and the number of tracks in each user area may be set within the beam deflection scanning range of the pickup. Can almost double the amount of data. However, arranging the spare area in the center in this way makes it difficult to compensate for sector defects by SR. Further, the present invention is not limited to a DVD-RAM, and can be applied to other disk media. Further, the present invention can be applied to not only a recording / reproducing disk medium but also a reproducing-only disk medium.

[Brief description of the drawings]

FIG. 1 is a data format of a logical zone according to an embodiment;

FIG. 2 is a conceptual view of the appearance of a DVD-RAM.

FIG. 3 is a logical format of a DVD-RAM.

Claims (2)

[Claims] 1. A logical format comprising a user area and a spare area is arranged on spiral and / or concentric tracks to form a unit logical zone, and the number of radial tracks between the user area and the spare area is determined by: A disk medium set within a beam deflection scanning range of a pickup. 2. The apparatus according to claim 1, wherein when the number of radial tracks between the user area and the spare area is different at a position on a disk, the maximum number of radial tracks is set within a beam deflection scanning range of a pickup. A disk medium characterized by the following.