JPS62209776A - Track format system for recording medium - Google Patents

Abstract

PURPOSE:To contrive a quick response in an error processing time, and to suppress reduction in user bytes at the minimum level, by allocating variably the number of alternate sectors in one track on a recording medium corresponding to the number of sectors in one track. CONSTITUTION:Track groups N1, N2, N3, and N4 in a data recording part on a disk plane has different number of sectors respectively, for example, they have 50 sectors, 45 sectors, 38 sectors, and 33 sectors per track group respectively. In the track group N1, two sectors, Sn-1, and Sn out of 50 sectors, are used as alternate sectors. In the track group N2, two sectors shown in figure out of 45 sectors are used as the alternate sectors. And in the track group N3, one sector shown in figure out of 38 sectors is used, and in the innermost peripheral track group N4, one sector shown in figure out of 33 sectors is used respectively. Thus, it is possible to perform the quick response in the error processing time, and also, to suppress the reduction in the user bytes at the minimum level.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a track disk of a storage medium used in an information storage device,
It relates to formatting, and in particular to alternate sector allocation for disks having different track formats on the disk.

[Prior Art] Conventionally, there are devices of this type that use magnetic disks, optical disks, magneto-optical disks, etc. An optical disk device will be described below as an example.

When recording information on an optical disk that rotates at a constant angular velocity, the minimum pit diameter is limited by the beam diameter of the laser beam used for recording and reproduction. The conditions are most severe at the inner circumference, and the transfer rate of recorded data is determined by the pit diameter and rotational speed at the innermost circumference of the disk. In this case, efficiency deteriorates toward the outer periphery of the disk when recording density is considered, and as a result, in the constant angular velocity disk, the recording capacity per surface of the disk is not optimized.

On the other hand, as a way to prevent this, the recording density can be increased by optimizing the linear velocity considering the pit diameter and rotating the disc-shaped recording medium so that the linear velocity in the track direction is constant on the disc surface. The so-called C, L, and V
(Constant Linear Velocity) method.

However, in this method, the rotation speed of the disk must be changed in the radial direction of the disk so that the linear velocity in the track direction is constant. It takes a lot of time to control the rotation of the disk, and the disadvantage is that the access time is longer than in the constant angular velocity (C, A, V) system.

Therefore, the high-speed accessibility of the C, A, V method and the C, L
, V. A system having the large capacity characteristics of the systems is described in Japanese Patent Application No. 1982-23327 by Mizu Applicant. According to this method, C, A, V.

The above-mentioned high-speed access and large capacity can be achieved by rotating the disk in the radial direction of the disk, dividing one rack into hands in the radial direction of the disk, and recording by changing the recording frequency in each track group.

According to an example of this new method, four track groups N1. N2. The data recording areas for each track group are f1 and t', respectively.
2. f3. Recording is performed at a clock rate of f4. For some pre-formatted Verata, N...
For both track groups of N2, at f2 clock rate,
N3. Both track groups of N4 are recorded at f4 clock rate 1.

In the above case, the number of sectors per each track IY N1 to N4 is, for example, 50 sectors, 45 sectors, 38 sectors, respectively on a 20 cm diameter disk.
There are 33 sectors (the derivation of this number is detailed in the above-mentioned Japanese Patent Application No. 60-23327).

Now, regarding spare sectors, C, A, and V type disks usually have a fixed track format on the disk, and for example, when one track has 64 sectors, two sectors are allocated as spare sectors. On the other hand, in a C, L, V type disk, a fixed number of replacement sectors are allocated for each fixed number of sectors.

[Purpose] The present invention has been made in view of the above points, and includes C, A, V,
The purpose of this invention is to provide a new method for allocating replacement sectors that does not rely on the replacement sector allocation method in the C, L, and V methods.

[Example] An example of the present invention will be described below with reference to FIG.

FIG. 1 shows an example of a track and sector format on a disk surface.

N1. N2. N3. N4 indicates a track group of the data recording section. Within each track group, the data recording section of each sector is recorded at the same clock rate, and therefore reproduction is also sampled and recorded by the reproduction clock approximately at that clock rate. The data is played back.

For example, the N1 track signal on the outer circumference of the disk is recorded at the f1 clock rate, the N2 track group is recorded at the f2 clock rate, N3 is recorded at the f3 clock rate, and the innermost track group N4 is recorded at the f4 clock rate.

Of course, fl>f2>f3>f4, and by doing so, the recording density on the disk surface can be roughly optimized.

The first header portion of each sector indicated by diagonal lines in FIG. 1 is composed of an M1 bunt including recording track groups N, , N2 in the radial direction, and an N3 band, as shown on the disk surface. It consists of N2 bands including N4 recording tracks. M,,N2
Parts of both headers are preformatted on optical discs, etc., and the recording clock rates therein are f2. Therefore, the read clock rate is also near f2.f4. With f4? ,<ru.

By the way, N,,N2. The N3 and N4 recording track groups each have a different number of sectors; for example, in the case of a disk format with a diameter of 20 cm, the user's by 1- is set to 512 B (bytes)/sector, and each track in each track group has 50 sectors; 45 sectors,
There are 38 sectors and 33 sectors (details can be found in the patent application filed in 1986).
-233, No. 27). The number of sectors mentioned above varies greatly depending on the format, modulation method, error correction method, etc., and is of course not fixed.

In FIG. 1, the outermost track group N, or So.

Sl +-5n-2+ 5n-1, (n+1) sectors/tracks of Sn are schematically illustrated.

” In the double example, (n+1)=50 sectors.

Therefore, regarding the allocation of replacement sectors to each track group,
For example, as shown in Figure 1, N, in the track group, S,
, , So are treated as alternate sectors. For example, in the above example of 50 sectors, 2 sectors (2150:4%) are used as replacement sectors.

Similarly, in the N2 track group, 2 sectors out of 45 sectors, 2/45Z4.4% as shown, are used as replacement sectors. In the N3 track group, one sector out of 38 sectors is used as an alternate sector as shown in the figure, and in the innermost N4 track group, one sector out of 33 sectors is used as an alternate sector as shown in the figure. N3. N4
The proportions of replacement sectors are 26% and 3%, respectively.

As shown in FIG. 1, the number of alternate sectors is 1 to 2 depending on the number of sectors in each track group, but the optimum value for this number is determined by the system design of the information record t@*B. However, in general, outer tracks have a large number of sectors, and therefore there will be a large number of defective sectors that cannot be corrected due to probability, so replacement sectors are allocated according to the number of sectors on one track. It turns out.

In the above embodiment, the number of spare sectors is allocated according to the number of sectors in one track. (If the number of defective sectors is not proportional to the number of sectors on one track on the innermost circumference, you may flexibly allocate replacement sectors according to the actual situation. For example, in the innermost circumference and the outermost circumference, For example, increasing the number of replacement sectors.

[Effect] As explained above, in a track format in which the number of sectors of a track on a recording medium is different, the replacement sector can be changed according to the number of track sectors.
``The following effects can be obtained by using J.

(1) Considering the sector error probability after disk error correction, sector defects occur according to the number of track sectors, so by allocating replacement sectors accordingly, it is possible to quickly respond to error IA filling. (Error processing can be done quickly within the same track).

(2) Almost uniform alternate sector allocation across the front surface of the disk makes it possible to minimize the decrease in user bytes.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the track format of a disc.

Claims (1)

[Claims] In a recording medium having a track format in which the number of sectors in one track is different on the recording medium, a track formatting method for a recording medium is characterized in that the number of alternate sectors in one track is variably allocated according to the number of sectors in one track. .