JP3230247B2 - Data recording / 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 recording / reproducing method for controlling the rotation of a disk at a speed higher than a required transfer rate.

[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 is traced from the start position of the first sector of each track to the end position of the last sector. The process of returning to the start position of the sector is repeated. For example, as shown in FIG.
Are traced from the sector S0 of the track T _n to S7,
And track jump back to the beginning of the sector S0 of the track T _n, again, the process as traced from the sector S0 of the track T _n until sectors S7 is repeated.

[0003]

However, in practice,
As shown by the arrow C, since a track jump time is required, a reproduced signal of a sector traced immediately after the track jump cannot be obtained. Therefore, as described above, tracing is performed from the start position of the first sector S0 of each track to the end of the last sector S7. Is repeated, the signal of the first sector S0 of each track cannot always be obtained. When the disk is rotated at n times speed, it is conceivable to perform a process of tracing the number of tracks n and then returning to the original state.
However, in such a process, time alignment cannot be performed properly due to the relationship between the original transfer rate and the rotational speed of the disk.

Accordingly, an object of the present invention is to provide a data recording / reproducing method which can improve the reliability of data in all sectors and easily perform time alignment when a disk is rotated at high speed. .

[0005]

SUMMARY OF THE INVENTION According to the present invention, an original rotation
Rotate the disk at a constant angular speed at a speed faster than the speed,
A track made of a plurality of sectors as a predetermined unit, and to record / reproduce repeated several times scanning of a predetermined unit
A data recording / reproducing method in which a disc makes one revolution
The time required for the disc is u,
The time required for one revolution is v, the time required for track jump
T, the number of unit tracks i, and the number of scan repetitions
N, select t = ju (j is a positive integer), and from the end
Let w be the time to move to the start end, and make [w / u] greater than w / u
T = ju, j = [w / u]
And the number of scanning repetitions N and the number of unit tracks i satisfying u (i + j) N-uj = vi ,
Data recording / reproducing method for recording / reproducing disks
Is the law .

According to the present invention, a disk is rotated at a constant angular velocity at a speed higher than a required transfer rate, and scanning of a predetermined unit is repeated a plurality of times with a plurality of sectors as a predetermined unit, and recording and confirmation of a recording state are performed. This is a data recording method in which the scanning of a unit is repeatedly performed so that the scanning comes to the head of the next predetermined unit.

[0007]

The control is performed such that the scanning of the predetermined unit i-track is repeated N times and the scanning of the predetermined unit i-track is repeated N times, and then the scanning returns to the head of the next predetermined unit.
This eliminates the need for time alignment and facilitates control when rotating the disk at high speed.

[0008]

An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, in one embodiment of the present invention, the original rotation speed is b (b is rpm (rotation /
The optical disk 1 represented by) in minutes), which from the high rotational speed a (a is rotated at rpm (represented by rev / min)), the scanning unit of the track number i to repeat N times Control. With this control, when the scanning of the unit of the number of tracks i is completed N times, it is possible to return to the head of the unit of the next track i.

The conditions at this time will be considered. Now, when the optical disk 1 is rotated at the rotation speed a, the time u required for the optical disk 1 to make one rotation is as follows: u = 60 / a seconds (1)

Assuming that the optical disk 1 is rotated at the original rotational speed b of the target optical disk 1, the optical disk 1
The time v required to make one rotation is: v = 60 / b seconds (2)

When the optical disk 1 is rotated at the rotation speed a, the time required for scanning by the unit track number i is as follows.
From the equation (1), the time required for rotating the optical disc 1 once is u, so that ui... (3) is obtained.

Assuming that the time required for the track jump is t, when the optical disk 1 is rotated at the rotational speed a and the scanning of the unit track number i is repeated N times, the time required is (ui + t) (N−1) + ui. (4) That is, when the optical disk 1 is rotated at the rotation speed a and the scanning of the unit track number i is performed N times, the track jumps to the first track every time the scanning is repeated up to (N-1) th time. Since the track N does not return to the first track, the time (ui + t) (N-1) required until the (N-1) th time and the time u required for the Nth time
× i.

On the other hand, from equation (2), the time required to scan the unit track number i at the original data rate is the time required for the optical disk 1 to make one rotation when the optical disk 1 is rotated at the original rotation speed b. Since the time is v, vi... (5) is obtained.

When the optical disk 1 is rotated at the rotation speed a and the scanning of the unit track number i is repeated N times, the optical disk 1 as a target represented by the formula (5) is required to position the pickup at the head of the unit. The time when scanning is performed by the unit number of tracks i while rotating at the original rotation speed b,
It is necessary to match the time when the scanning of the unit track number i is repeated N times at the rotation speed a shown in the equation (4). That is, the conditions at this time are as follows. (Ui + t) (N-1) + ui = vi (6) u: time required for the optical disk 1 to make one rotation v: time required for the optical disk 1 to make one rotation at the original rotation speed of the target optical disk 1 Time t: Time required for track jump i: Number of unit tracks N: Number of scanning repetitions

Therefore, the number i of unit tracks and the number N of scanning repetitions satisfying the equation (6) may be set.

Here, the time t required for the track jump is t
Depends on the number of unit tracks i and the rotation speed a of the optical disc 1. In one embodiment of the present invention, t = ju (j is a positive integer) is selected. Assuming that the time required to move from the end to the start track (or the immediately preceding track) is w, [w
/ U] is the smallest integer larger than w / u, and t = ju, j = [w / u] (7)

In the equation (7), the equation (8) is rewritten. u (i + j) N- uj = vi ... (8) and that Do not.

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 disk 1, data in ISO format and data in CD format 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 24 into an analog signal is provided. The reproduced audio signal is taken out as a digital signal from the digital output terminal 26 and the analog output terminal 2
7 is output 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 optical disk 1 is controlled to rotate at a high speed and repeat scanning in units of the number of tracks i N times. The control at this time will be described with reference to a flowchart shown in FIG.

First, at the original rotation speed, the optical disk 1
It is determined whether the time v required for one rotation of the optical disk 1 is equal to the time u required for the optical disk 1 to make one rotation (step 51). Optical disc 1 at the original rotation speed
If the time v required for one rotation of the optical disk 1 is equal to the time u required for the optical disk 1 to make one rotation, normal recording / reproduction is performed (step 52).

If the time v required for the optical disk 1 to make one rotation at the original rotational speed is not equal to the time u required for the optical disk 1 to make one rotation, the number of unit tracks i and the number of scanning repetitions N are read ( Step 53).
Then, the current track number i _A and the current scan repetition number N _A are initialized to 0 (step 54).

The current track number i _A is equal to the unit track number i.
Is determined (step 55). If the current track number i _A does not reach the unit track number i, the current track number i is calculated every time the track is scanned.
_A is incremented (step 56).

If it is determined in step 55 that the current track number i _A has reached the unit track number i, it is determined whether the current scan repetition number N _A has reached the scan repetition number N (step 57). ). If the current number of scan repetitions N _A does not reach the number of scan repetitions N, the current number of scan repetitions N _A is incremented and the current number of tracks i _A is set to 0 each time a unit scan is performed. Is performed (step 58). Then, a track jump is made to the head (step 59), and the process returns to step 55.

Such a control is repeated. When the scanning of the unit track number i is repeated N times, it is determined in step 57 that the current scanning repetition number N _A has reached the scanning repetition number N. Then, scanning for the next unit track number i is performed (step 60).

[0030]

Effects of the Invention According to this invention, the disc is rotated at a high speed, by repeating N times the scan unit track number i, have access to the next unit, there is no need for time alignment. Further, according to the present invention, control of a track jump position and control of a buffer memory can be easily performed.

[Brief description of the drawings]

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

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

[Explanation of symbols]

 1 optical disk 18 RAM 28 controller

Claims (1)

(57) [Claims] Rotating the disk at a constant angular velocity at 1. A faster than the original speed speed, the track comprising a plurality of sectors as a predetermined unit, as repeatedly recorded / reproduced several times scanning of the predetermined unit
A time required for the disk to make one revolution is u,
The time required for the disc to make one revolution at the speed of rotation
The interval is v, the time required for the track jump is t,
The number of checks is i, the number of scan repetitions is N, and t = ju (j is
Positive integer), and the time from the end to the start is w and
And let [w / u] be the smallest integer greater than w / u, and t
= Ju, j = [w / u], the number of scan repetitions N and the number of unit tracks i that satisfy u (i + j) N-uj = vi
Record / reproduce data on / from a disc
Raw method.