JP2889714B2 - Optical recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus capable of recording / reproducing information on / from an optical disk in which areas having different recording formats are mixed.

[0002]

2. Description of the Related Art In recent years, as a new recording medium, an optical disk for recording and reproducing information by using a light beam such as a laser beam has attracted attention. This optical disk has different functions
There are a reproduction-only type, a so-called write-once type in which recording by a user can be performed only once, and a rewritable type in which recording and erasing can be repeated. In such an optical disc, it is conceivable to mix different recording formats on one disc. For example, it is conceivable to mix a read-only area formed by a pit row and a rewritable area formed by a magneto-optical recording layer. In the case of such a disc, for example, when shifting from the read-only area to the rewritable area, the tracking operation or the like may become unstable due to a different recording format.

[0003]

In this kind of optical disc, an address indicating the head position of each piece of information recorded on the disc may be recorded at the beginning of the disc as table of contents information. For example, on a compact disk, this part is called TOC (Table of Content). Therefore, the address of the boundary can also be recorded as the table of contents information. According to the present invention, when recording / reproducing an optical disc in which areas having different recording formats coexist, it is possible to detect in advance that the vicinity of the boundary portion has been reached by using the address of the boundary portion recorded in the table of contents. The recording / reproducing operation in the portion is controlled stably.

[0004]

Therefore, according to the present invention, in an optical disk recording / reproducing apparatus in which areas having different recording formats are mixed and in which address information of a boundary between the areas is recorded, the present invention is applied. A memory for storing an address of a boundary portion of the output region; a boundary detection means for detecting that a difference between a current reproduction address and a boundary portion address stored in the memory has reached a predetermined value; A track jump means for jumping the irradiation point of the light beam according to the detection output of the means is provided.

[0005]

According to the above arrangement, the boundary portion is detected in advance,
A track jump can be performed so as not to scan this boundary portion. Therefore, the recording / reproducing operation at the boundary does not become unstable.

[0006]

FIG. 2 is a schematic view of a disc 1 in which areas of different recording formats are mixed. This disc 1 has a read-only area 1a (for example, information is previously recorded in a pit row like a compact disc). Portion) and a rewritable area 1b (for example, a magneto-optical recording area). In addition, 1e
Is the center hole of disk 1.

Data information is recorded in the read-only area 1a. At the beginning of the data information, the head address of each data information recorded in the read-only area 1a is recorded as in the conventional compact disk. The addresses of the boundary portions 1c and 1d of the area are also recorded.

The rewritable area 1b is of a so-called pre-groove type, and a magneto-optical recording layer is formed in a groove. This groove meanders at a predetermined cycle, and by modulating this cycle according to the address, the rewritable area 1 is changed.
The address can be recorded in advance for b.
Therefore, the address can be reproduced at the same time as recording information in the rewritable area 1b.

FIG. 1 shows a block diagram of an apparatus according to the present invention. The disk 1 is driven to rotate at a constant linear velocity by a spindle motor 2 having a spindle shaft. The optical head 3 records or reproduces information on the disk 1. At the time of recording, information to be written is applied to the optical head 3. At the time of reproduction, the signal picked up by the optical head 3 is subjected to waveform shaping by the waveform shaping circuit 4 and then demodulated by the demodulation circuit 5. The signal thus demodulated includes data information and address information. The spindle motor 2 is controlled by a servo circuit 6 so as to have a constant linear velocity. Also, the optical head 3
In the same manner, tracking control and focus control are performed by the servo circuit 6. Since the above configuration is a conventionally known configuration, it is simplified in FIG.

The configuration of the main part of the present invention is as follows. Prior to the recording / reproducing operation of the disk, first, the first part of the reproduction-only area 1a is reproduced.
The address information among the signals output from the above is detected by the address detecting means 7 and stored in the memory 8.

[0011] Of the address information stored in the memory 8, an address indicating the boundary of the area is read and applied to the address comparing means 9. On the other hand, the reproduction-only area 1
The current reproduction address output from the address detection means 7 during reproduction of a or the current reproduction address output from the address detection means 7 during recording or reproduction of the rewritable area 1b is also compared with the address comparison means. 9 is applied. Then, the boundary comparing unit 9 detects whether or not the difference between the current reproduction address and the boundary address has reached a predetermined value (for example, one track).

On a disk with a constant linear velocity, the difference between the address of the boundary portion and the address of a portion one track before this portion does not become a constant value, but the position of the boundary portion in the disk radial direction, that is, the boundary address. Will be different depending on the size of. Therefore, the boundary detecting means 10 determines whether or not the difference between the two addresses has reached a predetermined value determined in consideration of the size of the boundary address.

When the boundary detecting means 10 detects that the irradiation point of the light beam, that is, the recording or reproducing point is one track before the boundary, the control circuit 11 responds to this.
Further, a track jump pulse for two tracks is supplied to the optical head 3 via the servo circuit 6, and a two-track jump is performed. In this way, recording or reproduction of the track at the boundary can be avoided.

For example, when a so-called three-beam tracking control system is used, the tracking control sub-beam is affected by tracks having different recording formats at the boundary between the regions, and the tracking control signal becomes unstable. It is possible. Therefore, by making the light beam track jump so as not to scan the track at the boundary portion, stable tracking control can be expected, and good recording and reproduction can be performed.

At the boundary, a track jump is performed by the control circuit 11, and when the reproduction operation shifts to an area different from the one before, the characteristic of the waveform shaping circuit 4 is switched to the characteristic according to the recording format of the area after the shift. And good. A signal for this switching is output from the control circuit 11 at the same timing as the track jump pulse.

Further, as the optical head 3, for example,
The one described in "Radio Science", February 1985, page 101, can be used, but in this case, the method of creating an information signal from a photosensor differs depending on the recording format. Therefore, the signal for switching for this is also
Output from the control circuit 11.

[0017]

According to the present invention described above, when recording / reproducing is performed on an optical disc in which areas having different recording formats are mixed, the boundary portion is configured to jump the track. The recording / reproducing operation does not become unstable.

[Brief description of the drawings]

FIG. 1 is a block diagram of a magneto-optical recording / reproducing apparatus according to the present invention.

FIG. 2 is a schematic diagram of a disk in which areas of different recording formats are mixed.

[Explanation of symbols]

 Reference Signs List 8 memory 9 address comparing means 10 boundary detecting means 11 control circuit (track jumping means)

Claims (1)

(57) [Claims] An area having a different recording format is mixed.
An optical disk recording / reproducing apparatus in which address information of a boundary portion of an area is recorded, wherein a memory for storing an address of a boundary portion of the area read in advance, a current reproduction address and a memory stored in the memory are provided. Boundary detection means for detecting that a difference from the boundary part address becomes a predetermined value, and track jump means for jumping the irradiation point of the light beam according to the detection output of the boundary detection means. Optical recording and reproducing device.