JP3036114B2 - Data playback 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 data reproducing method in which the rotational speed of a disk is made faster than the original data transfer speed to improve data reliability.

[0002]

2. Description of the Related Art There is known a data recording / reproducing apparatus in which data reliability is improved by rotating a disk at a high speed. As described above, when the disk is rotated at a high speed, conventionally, the track from the start position of the first sector of each track to the end position of the last sector is traced. The process of returning to the start position of the first sector is repeated. For example, as shown in FIG. 4, 1 if the track is playing a disc of 8 sectors is rotated at a high speed is first traced from the sector S0 of the track T _n to sectors S7, it is traced to the last sector S7 Once, jumping over the tracks, back to the beginning of the sector S0 of the track T _n, sector S of the track T _n again
The process of tracing from 0 to sector S7 is repeated. When the speed of the disk is 8 times, such processing is repeated eight times. For this reason, in principle, each of the sectors S 0 to S 7 on the same track is traced eight times, and the reliability of the reproduced data is improved.

[0003]

However, in practice,
As indicated by the arrow C, since a time is required for the track jump, a reproduced signal of a sector traced immediately after the track jump cannot be obtained. Therefore, as described above, when the process of tracing the track and returning to the start position of the first sector S0 of the previous track when the last sector S7 is traced is repeated, the first sector of each track is always obtained. The signal of S0 cannot be obtained.

Accordingly, an object of the present invention is to provide a data reproducing method capable of improving the reliability of data for all sectors when a disk is rotated at high speed and the same track is traced a plurality of times.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a disk is rotated at a speed higher than a rotation speed for realizing a transfer rate of recorded data, and when a predetermined track is scanned, a track jump is performed to make the same track as the predetermined track. In a data reproducing method in which a track is scanned a plurality of times,
This is a data reproducing method characterized in that a position of a track jump is made different when a predetermined track is scanned a plurality of times.

[0006]

By making the track jump positions different sequentially, sectors that are not reproduced are dispersed, and the reliability of data can be improved for all sectors.

[0007]

An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, tracks T _n , T _{n + 1} ,... Are formed on the optical disc 1 in a spiral shape, for example. Each track T _n , T _{n + 1} ,.
It is divided into two sectors S0 to S7. This disk 1
Is rotated at, for example, eight times the original rotation speed. At this time, the position of the track jump is sequentially shifted as follows.

[0008] First, be traced to the sector S0~S7 track T _n, reaches the sector S0 of the T _{n + 1} of the next track, as indicated by the arrow B0, is a track jump to the sector S1 of the track T _n . At this time, since there is a need for time of track jump, it can not be sector S0 mother playback of the track T _n.

[0009] Next, be traced to the sector S1~S7 track T _n, further reaches the T _{n + 1} of the sector S1 of the next track, as indicated by the arrow B1, the track T _n
A track jump is made to sector S2. In this case, since time is required for the track jump, the sector S1 of the track T _n can not be regenerated.

[0010] Next, be traced to the sector S2~S7 track T _n, further, the next track T _{n + 1} sector S
Until 0~S1 traced, reaches the T _{n + 1} of the sector S2 of the next track, as indicated by arrow B2, is a track jump to the sector S3 in the track T _n. At this time,
Since track jump time is required, track T
The sector S2 of _n cannot be reproduced.

[0011] Next, be traced to the sector S3~S7 track T _n, further, the next track T _{n + 1} sector S
Until 0~S2 traced, reaches the T _{n + 1} of the sector S3 in the next track is a track jump to the sector S4 in the track T _n. In this case, since time is required for the track jump, the sector S3 in the track T _n can not be regenerated.

[0012] Next, be traced to the sector S4~S7 track T _n, further, the next track T _{n + 1} of the sector S
0~S3 is traced to the, reaches the T _{n + 1} of the sector S4 in the next track, as indicated by the arrow B4, is a track jump to the sector S5 in the track T _n. At this time, since there is a need for time of track jump, sector S4 of track T _n can not be regenerated.

[0013] Next, be traced to the sector S5~S7 track T _n, further, the next track T _{n + 1} sector S
0~S4 is traced to the, reaches the T _{n + 1} of the sector S5 in the next track, as indicated by the arrow B5, is a track jump to the sector S6 in the track T _n. In this case, since time is required for the track jump, the sector S5 in the track T _n can not be regenerated.

[0014] Next, be traced to the sector S6~S7 track T _n, further, the next track T _{n + 1} sector S
0~S5 is traced to the, reaches the sector S6 in T _{n + 1} of the next track, as indicated by arrow B6, is a track jump to the sector S7 in the track T _n. In this case, since time is required for the track jump, the sector S6 in the track T _n can not be regenerated.

[0015] In this manner, when sequentially shifting the position of the track jump, the sector can not play the track T _n the sector S0, S1, S2, S3, ... 'll move to the order of,
There are no sectors that cannot always be obtained by multiple traces. Therefore, the reliability can be improved over all the sectors.

FIG. 2 shows an example of a disk recording / reproducing apparatus for recording / reproducing the optical disk 1. This optical disk recording / reproducing apparatus is provided with a SCSI interface 21. SCSI interface 21
By connecting the optical disk recording / reproducing apparatus to a computer via the PC, the optical disk recording / reproducing apparatus can be operated as a peripheral storage device of the computer. A SCSI controller 22 is provided so that data can be input / output using the SCSI interface 21.

On this optical disc 1, ISO format data and CD format data are recorded / reproduced. A CD and CD-ROM encoder / decoder 24 are provided so that data can be recorded / reproduced on the optical disc 1 in a CD format. Further, a D / A converter 25 for converting an audio signal decoded by the CD-ROM decoder / encoder 24 into an analog signal is provided. The reproduced audio signal is extracted from the digital output terminal 26 as a digital signal, and is output from the analog output terminal 27 as an analog signal.

The rotation of the optical disk 1 is controlled by a spindle motor 11. The optical disc 1 is rotated at a speed higher than the speed at which a normal data transfer rate is achieved in order to improve data reliability and the like. For this reason, the data transfer rate for recording / reproducing data on the optical disc 1 is different from the data transfer rate for input / output. A RAM 18 is provided to match the data transfer rate for recording / reproducing data on the optical disc 1 with the data transfer rate for input / output. This RAM1
8 is controlled by the RAM controller 23. The control of the entire recording / reproducing apparatus is performed by the controller 28.

The magnetic head 12 faces the optical disk 1.
And the optical head 13 are provided so as to face each other.
The magnetic head 12 is driven by a magnetic head drive circuit 14. A reproduction signal of the servo area of the optical disk is supplied to the servo circuit 17 via the reproduction amplifier 19. The rotation of the spindle motor 11 is controlled by a servo circuit 17. In addition, tracking control is performed by the servo circuit 17.

At the time of data recording, data from the SCSI interface 21 or from the CD / CD-ROM encoder / decoder 24 is stored in the RAM 18,
The output of the RAM 18 is supplied to the modulation / demodulation circuit 15.
In the modulation / demodulation circuit 15, data is modulated by a predetermined modulation method. The output of the modulation / demodulation circuit 15 is supplied to the magnetic head drive circuit 14. A modulation magnetic field is generated from the magnetic head 12 by the output of the modulation / demodulation circuit 15. This modulation magnetic field is applied to the optical disc 1. At the same time, a laser beam is emitted from the optical head 13 according to the output of the laser drive circuit 16. This laser beam is applied to the optical disc 1. Thus, data is recorded on the optical disc 1 in the form of the magnetization direction of the perpendicular magnetization film.

At the time of reproduction, a laser beam from the optical head 13 is irradiated on the optical disk 1, and reflected light of the laser beam is detected. The rotation angle of the reflected light of the laser beam differs depending on the magnetization direction of the perpendicular time film of the optical disc 1. The recorded data on the optical disc 1 is reproduced according to the rotation angle of the reflected light of the laser beam. The reproduction signal of the optical disk 1 is supplied to the modulation / demodulation circuit 15 via the reproduction amplifier 19. The modulation / demodulation circuit 15 demodulates the data. The output of the modulation / demodulation circuit 15 is stored in the RAM 18
Supplied to The output of the RAM 18 is decoded via the SCSI interface 21 or by the CD and CD-ROM encoder / decoder 24 and output.

As described above, in the optical disk recording / reproducing apparatus to which the present invention is applied, the track jump position is shifted when rotating the optical disk 1 at high speed.
FIG. 3 shows an example of the control at this time.

As shown in FIG. 2, each sector of the optical disk 1, the sector S ₀ of the track T _n, S _1, S _2, ...,
S _7, the sector S ₀ of the track _{T n + 1, S 1,} S 2, ...,
In response to S _7, the address _{A n, 0, A n,} 1, A n, 2,
..., _{An, 7} , addresses _{An + 1,0} , _{An + 1,1} , _{An + 1,2} ,
.., _{An + 1,7} are provided.

First, the address of the sector is read (step 51). It is determined whether the read sector is the last sector of the read sector (step 52).

If the read sector is not the last sector, j is first set to 0 (step 53). Then, it is determined whether the current address of the read sector has reached An _{+ 1, j} (step 54). First, since j is set to 0, it is first determined whether the current address has reached A _{n + 1,0} , that is, whether the current address has reached the first sector S ₀ of the next track.

Then, the sectors S ₀ , S ₁ , S ₂ ,... Are sequentially accessed, and the addresses _{An, 0} , _{An, 1} , _{An, 2} ,.
Are sequentially read (step 55). Eventually, the first sector S _{0 of} the next track T _{n + 1} is accessed. Therefore, the current address to be read reaches _{An + 1,0} .

When the current address to be read reaches A _{n + 1,0} , the track jumps to the sector at the address A _{n, j + 1} , that is, the sector S ₁ of the track T _n (step 56). .

It is determined whether or not j has reached 6 (step 57). If j has not reached 6, j is incremented. That is, at this time, j is set to 1 (step 58).

Then, the address of the sector is read (step 55), and whether the current address of the read sector has reached A _{n + 1,1} , that is, has reached sector S ₁ of the next track. It is determined whether or not it is (step 54).

Then, the sectors S ₁ , S ₂ , S _3, ... Are sequentially accessed, and the addresses _{An, 1} , _{An, 2} , _{An, 3} ,. Eventually, the sector S1 of the next track _{Tn + 1} is accessed. Therefore, the current address to be read reaches _{An + 1,1} .

[0031] In step 54, the current address to be read, reaches the A n _{+ 1, 1,} made address A _n, and _{j + 1} section
Data, i.e., at this time, the track T _n sectors S ₂
Is jumped to the track (step 56)

Thereafter, the same control is repeated. When j becomes 6 in step 57, n is incremented (step 59). Then, the process returns to step 51.

By performing such control, as described above, a process of shifting the track jump position can be realized.

[0034]

According to the present invention, when the same track is traced a plurality of times by rotating the optical disc at a high speed,
The positions of the track jumps are sequentially changed. For this reason, the sectors that are not reproduced are dispersed, and all the sectors can be traced a plurality of times, thereby improving the data reliability.

[Brief description of the drawings]

FIG. 1 is a plan view used for describing an optical disc in a data reproducing method to which the present invention is applied.

FIG. 2 is a block diagram of an example of a data recording / reproducing apparatus to which the present invention is applied.

FIG. 3 is a flowchart used to explain an embodiment of the present invention.

FIG. 4 is a plan view used to explain a conventional data reproducing method.

[Explanation of symbols]

 1 optical disk 28 RAM 18 controller

Claims (1)

(57) [Claims] A disk is rotated at a speed higher than a rotation speed for realizing a transfer rate of recorded data, and when a predetermined track is scanned, a track jump is performed so that the same track as the predetermined track is scanned a plurality of times. In the data reproducing method described above, the position of a track jump is made different when scanning the predetermined track a plurality of times.