JPS63166074A - Disk device - Google Patents

Abstract

PURPOSE:To detect a leading sector at each track in real time, by arranging a sector mark at the leading sector of each track differently from the sector mark arranged at another sector. CONSTITUTION:For example, when a track is constituted of eight sectors (sector 0, sector 1, sector 2-sector 7), the sector mark 3 arranged at the forefront of the sector 0 is formed differently from the sector marks 4, 4 arranged at other sectors except the sector 0. For example, the sector mark arranged at the forefront of the sector 0 is constituted in such way that it consists of a part (0) with time width A, a part (1) with time width B, and a part (0) with time width C as shown in figure (a), and the sector marks of the sectors other than the sector 0 are set as shown in figure (g). Thus, since the sector mark of the sector 0 is formed differently from those of other sectors, it is possible to detect the forefront of the track in real time.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a disk device for reading data, or writing and reading data.

BACKGROUND OF THE INVENTION FIG. 6 shows a recording disk used in a conventional optical disk device. In FIG. 6, reference numeral 1 denotes a recording disk, and tracks 2 are formed spirally on this recording disk 1. In FIG. Each track is composed of a plurality of sectors (for example, 16 sectors). In FIG. 6, one track is shown as eight sectors. The black dots in FIG. 6 indicate sector marks placed at the beginning of each sector.

In the above conventional example, the same sector mark is placed at the beginning of each sector.

Problems to be Solved by the Invention However, in the conventional example described above, since all sector marks are the same, it is not possible to accurately detect the 0 sector, which is the beginning of each track, in real time.

The present invention solves the above conventional problems and provides a disk device that can detect the leading sector of each track in real time.

Means for Solving the Problems In order to achieve the above object, the present invention has a sector mark placed in the first sector (0 sector) of each track and a sector mark placed in other sectors (sectors other than 0 sector). This is what makes the difference between the two.

According to the present invention, the beginning of a track can be easily detected in real time by detecting the sector mark of sector 0.

Embodiment FIG. 1 shows a recording disk in one embodiment of the present invention. Reference numeral 1 indicates a recording disk, and reference numeral 2 indicates a spiral track. In FIG. 1, only the first track 2TI and the second track 2T2 are shown.

Each trunk 2T, 2T2, . . . is composed of a plurality of sectors (for example, 16 sectors).

Note that FIG. 1 shows an example in which one track is composed of eight sectors (0 sector, 1 sector, 2 sectors, . . . , 7 sectors). 3 indicates a sector mark placed at the beginning of sector 0, and 4 indicates a sector mark placed at the beginning of a sector other than sector 0. Sector mark 3
and sector mark 4.

FIG. 2 shows the sector format.

In FIG. 2, 6 is a sector mark (sM), e is an ID section for recording addresses, etc., and 7 is a data section.

FIG. 3a shows a sector mark placed at the beginning of the 0 sector, which consists of a 1 time width A00 part, a 1 time width B part, and a time width C 0 part.

FIG. 4 shows a detection circuit for detecting the sector mark of the 0 sector shown in FIG. 3a. In FIG. 4, 8 is an input terminal to which a signal picked up from the recording disk is applied, 9a is a time width A detection circuit that detects time width A,
The time width A detection circuit 9a outputs a detection pulse (FIG. 3b) when the time width A is detected by sampling the signal input to the input terminal 8. Similarly, 9b,
Reference numeral 9c designates a time width B detection circuit 1 and a time width detection circuit 1 which outputs a detection pulse (FIG. 3c, d) when detecting time widths B and C, respectively. 10a is a shift circuit that shifts the detection pulse (FIG. 3b) output from the time width A detection circuit 9a by time (B+C); similarly, 10b is a shift circuit that shifts the detection pulse (Fig. 3b) output from the time width B detection circuit 9b; 11 is a majority circuit,
This majority voting circuit outputs one signal from the output terminal 12 when at least two detection pulses are detected at the timing when the detection pulse (FIG. 3 d) is output from the time width C detection circuit 9C.
Output. In the example shown in FIG. 3, the time width C detection circuit 9
At the timing when the detection pulse (Fig. 3 d) is output from c, the detection pulse (Fig. 3 e, f) and the detection pulse (Fig. 3 d) shifted by the shift circuits 10 a and 10 b
is input, the majority circuit 11 outputs 1. FIG. 3g shows an example of sector marks for sectors other than the 0 sector, and FIG. 5 shows the detection circuit 13 for detecting sector marks other than the 0 sector. This detection circuit 13
When the sector mark shown in FIG. 3g is input to the input terminal 14, 1 is output to the output terminal 15.

In the above embodiment, sector marks having three time widths A, B, and O are used, but sector marks having four or more time widths may be used.

As described above, in the above embodiment, a sector mark that is different from the sector mark placed at the beginning of other sectors is placed at the beginning of the O sector, so the 0 sector, that is, the beginning of the track, is detected in real time. can do.

Further, in the above embodiment, a sector mark can be detected at the end timing of the sector mark, and this timing can be used as a reference timing for data writing or data reading.

Effects of the Invention The present invention has the advantage that the beginning of the 0 sector, that is, the beginning of the track, can be detected in real time because the sector mark of the 0 sector is different from the sector marks of other sectors.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an outline of a disk used in a disk device according to an embodiment of the present invention, FIG. 2 is a diagram showing the sector format of the same disk, and FIG. 3 is a diagram showing a disk device according to an embodiment of the present invention. FIGS. 4 and 6 are block diagrams of a detection circuit for detecting sector marks in the same device, and FIG. 6 is a diagram schematically showing a disk used in a conventional disk device. 1゛°°°°Record 2T1.2T2...Track, 3
, 4... sector mark. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure! Figure 2 Figure 3 □ Fill A B C-=2 ρ E-
F -- Figure 6

Claims (1)

[Claims] A disk having a plurality of tracks, each track consisting of a plurality of sectors, and a first sector mark placed in the first sector of each track different from a second sector mark placed in other sectors. . A disk device comprising: first detection means for detecting the first sector mark from a signal read from the disk; and second detection means for detecting the second sector mark.