JPH0793904A - Information recording apparatus, information reproducing apparatus and optical disk - Google Patents

Abstract

PURPOSE:To prevent a data demodulation error per frame as generated by failed detection, erroneous detection or the like of a mark indicating the head of a frame. CONSTITUTION:When information is recorded oh a recording medium, a sector is divided equally into a plurality of frames and a frame mark 7 is arranged at the head of each frame to identify the head of the frame. One or a plurality of frames in the sector are recorded as an ID part 8 and the remaining frames in the sector as data part 9. This allows the arranging of the frame mark 7 as synchronous signal in the demodulation of data at a fixed interval.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording apparatus and an information reproducing apparatus for recording or reproducing information on a recording medium having a sector structure.

[0002]

2. Description of the Related Art When recording digital information on a recording medium such as an optical disk or a magnetic disk, it is general to divide a track into a plurality of sectors and record / reproduce the information in sector units.

FIG. 4 shows an example of a conventional sector structure. Each sector is composed of an ID section for recording a physical position on the recording medium and a data section for recording digital information. The ID part is a sector mark 21 that identifies the beginning of a sector.
And ID8 for recording ID information is triple-written. On the other hand, the data part has a PLL (Phase Lo).
cked Loop) A sync pull-in signal portion (VFO) for pulling in sync, a mark 22 (hereinafter, abbreviated as SYNC) for identifying the head of recording data, and a mark 23 for identifying the head of each data frame. (Less than,
(Abbreviated as RESYNC). here,
The ID part and the data part have completely different structures.

An information reproducing apparatus for reproducing information recorded in such a recording format from a recording medium is generally reproduced by the following method.

First, a sector mark indicating the beginning of a sector is detected, an address mark is detected with reference to this, and an address is read. On the other hand, the data part has a SYNC indicating the beginning of the data part and a RESYNC indicating the beginning of the frame.
C is detected, and word synchronization for data demodulation is taken,
Data is demodulated in frame units. This SYNC, R
If ESYNC cannot be detected and word synchronization for data demodulation cannot be established, all data in that frame will be in error. Therefore, for RESYNC that cannot be detected, an alternative signal is created from the previously detected RESYNC so that word synchronization can be achieved even if RESYNC cannot be detected.

[0006]

However, in the conventional information recording / reproducing apparatus as described above, SYNC, RES
YNC is arranged at a fixed interval in the data part,
Since it is not arranged in the ID part, the signals for word synchronization are not arranged at a constant interval when viewed in sector units. Therefore, if the SYNC indicating the beginning of the very first frame cannot be detected, the substitute signal must be created with reference to the sector mark or the last RESYNC of the immediately preceding sector. If a substitute signal is created based on the sector mark or the RESYNC of the previous sector, the substitute signal cannot be output at the correct position because the interval to SYNC is long, or the SYNC that is detected correctly is erased. There was a problem.

From a circuit perspective, the RESYNC
There is also a problem in that a circuit for creating the alternative signal of 1 and a circuit for creating the alternative signal of SYNC must be separately provided.

The present invention provides an information recording apparatus and an information reproducing apparatus for solving the above-mentioned drawbacks and preventing a data demodulation error in frame units caused by non-detection, erroneous detection, etc. of a mark indicating the beginning of a frame. The purpose is to do.

[0009]

To achieve this object, the present invention provides a frame mark for dividing a sector into a plurality of frames when recording information on a recording medium and identifying the beginning of the frame. Is placed at the beginning of each frame,
One or more frames in the sector are used as the ID part,
By recording the remaining frames in the sector as the data portion, the frame marks that serve as synchronization signals for data demodulation are arranged at regular intervals.

An information reproducing apparatus for reproducing the information recorded in this way has a means for detecting a frame mark, a means for generating an alternative signal from the immediately preceding frame mark when the frame mark cannot be detected, and a frame mark as a reference. And a means for performing data demodulation, and the data is demodulated on a frame-by-frame basis by word synchronization with the frame mark.

[0011]

According to the present invention, the sector is divided into a plurality of frames by arranging the frame mark at the head of each frame for recording, and when the frame mark cannot be detected from the reproduction signal at the time of reproduction, the present invention can It becomes possible to generate an alternative signal from the frame mark and demodulate in synchronization with the word of the data, and the error of the data demodulation due to the influence of the detection accuracy of the frame mark is reduced.

Further, since the frame marks are always arranged at regular intervals, only one circuit can be used to generate the alternative signal, and the circuit scale of the information reproducing apparatus can be reduced.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings. First, the operations of the information recording apparatus and the information reproducing apparatus according to the first embodiment of the present invention will be described in comparison with a conventional apparatus.

FIG. 1 shows a block diagram of the information recording apparatus of the first embodiment, FIG. 2 shows a sector format recorded on a recording medium, and FIG. 3 shows a block diagram of the information reproducing apparatus of the first embodiment. . FIG. 4 shows a conventional sector format, and FIG. 5 shows a block diagram of a conventional information reproducing apparatus.

First, the operation of the information recording apparatus of the first embodiment will be described with reference to FIG. Input data 1 is ID
An ID is added in sector units to the addition circuit 2, and the data modulation circuit 3 is input. Data modulation circuit 3 performs modulation suitable for recording, frame mark addition circuit 4 divides the frame into frames at regular intervals, and a frame mark is added to each frame. The frame mark adding circuit 4 enters the recording processing circuit 5, recording processing is performed according to the recording medium, and recording is performed on the recording medium 6. In the information recorded in this way, as shown in FIG. 2, one sector consists of a plurality of frames, and a frame mark 7 is arranged at the beginning of each frame.

Next, the operation of the information reproducing apparatus of the first embodiment will be described with reference to FIG. The information recorded on the recording medium with the sector structure as shown in FIG. 2 is reproduced from the recording medium 6 and enters the reproduction processing circuit 10. Here, the signal is amplified by a preamplifier or the like and enters the PLL 11. PLL11
At this time, a clock synchronized with the reproduction signal is created and enters the frame mark detection circuit 12 together with the reproduction signal, and the frame mark is detected from the reproduction signal.

The substitute signal generating circuit 13 counts clocks output from the PLL 11 with reference to the frame mark detected by the frame mark detecting circuit 12, and generates a substitute signal when the next frame mark cannot be detected. And outputs a substitute signal to the position where the frame mark should be detected. In this way, frame marks always enter the data demodulation circuit 14 at regular intervals. Here, the data is demodulated in frame units in word synchronization with the frame mark, and the output data 15 is output.

In the conventional sector format, as shown in FIG. 4, SYNC and RESYNC indicating the beginning of a frame are displayed.
The interval (corresponding to the frame mark of the present invention) becomes discontinuous in the ID part. Therefore, as shown in FIG. 5, in the reproducing apparatus, the sector mark detection circuit 16, the SYNC detection circuit 17, the RES
A SYNC alternative signal creation circuit 19 that includes a YNC detection circuit 18 to detect each mark, and if SYNC cannot be detected, creates a replacement signal based on the sector mark or RESYNC of the previous sector, and RE.
The alternative signal has to be created by including the RESYNC alternative signal creation circuit 20 that creates the alternative signal when SYNC cannot be detected.

On the other hand, in the information recording apparatus and the information reproducing apparatus of the first embodiment, the sector is composed of a plurality of equally divided frames at the time of recording, and the frame mark is arranged at the beginning of each frame. Since the frame marks can always be detected at fixed intervals during reproduction, it is possible to easily create an alternative signal from the immediately preceding frame mark when it is not detected.

In the conventional alternative signal generation method, RESYN
Depending on the position in the sector C, the last RESYNC creates a substitute signal for the SYNC of the next sector, and the other RESYNCs create a substitute signal for the next RESYNC. Therefore, when RESYNC is erroneously detected in the data, a substitute signal is created in a completely different place, which may cause a data demodulation error.

However, in the information reproducing apparatus of the first embodiment, since the frame mark always appears in a constant cycle, the substitute signal is not output to a completely different place, the data demodulation error is prevented, and the reliability is high. Playback is possible.

Since only the frame mark detection circuit and the alternative signal generation circuit are required, the information reproducing apparatus can be realized with a circuit configuration simpler than the conventional one.

Next, block diagrams of the information recording apparatus and the information reproducing apparatus of the second embodiment of the present invention are shown in FIGS. 6 and 7. Figure 8
Shows a sector format when recorded by the information recording apparatus shown in FIG.

The operation of the information recording apparatus of the second embodiment is the same as that of the information recording apparatus of the first embodiment up to the data modulation circuit 3. The data modulation circuit 3 enters the ID mark adding circuit 24, and the ID mark is added to the head of the ID portion. Next, a frame mark is added by the frame mark adding circuit 4 on a frame-by-frame basis and is recorded on the recording medium 6 through the recording processing circuit 5. The information thus recorded has a sector format as shown in FIG.

In the information reproducing apparatus, the ID mark detecting circuit 2
5, the ID mark is detected from the reproduced signal, and the ID
The ID is read by the ID decoding circuit 26 using the mark as a reference. The other operations are the same as those of the information reproducing apparatus described in the first embodiment.

By adding this ID mark, I
The frame in which D is recorded can be surely identified, and the ID can be surely read. Further, it is possible to reduce the false detection of the ID mark by opening the effective gate of the ID mark from the frame mark.

Next, as a third embodiment of the present invention, an information recording apparatus and an information reproducing apparatus having separate modulation and demodulation circuits for the ID section and the data section will be described. 9 and 10 are block diagrams of the information recording apparatus and the information reproducing apparatus of the third embodiment.

The input data 1 is modulated by the data modulation circuit 3 and I modulated by the ID adding circuit 2 by the ID modulating circuit 28.
Combined with D data. For the subsequent operation, see the second
This is the same as the information recording apparatus described in the embodiment.

The operation of the information reproducing apparatus for reproducing the information thus recorded is the same as that of the information reproducing apparatus explained in the second embodiment until the ID mark detecting circuit 25 detects the ID mark. The ID is detected by the ID demodulation circuit 29 with reference to the ID mark detected by the ID mark detection circuit 25.

As described above, when different modulation methods are used for the data section and the ID section, the data section uses the modulation having a large recording density ratio in consideration of the high density, and the ID section responds to the time-axis fluctuation of the reproduction signal. It is possible to configure a recording / reproducing apparatus capable of high-density recording and surely reading the ID by using a strong and strong modulation with a small maximum inversion interval.

Although only one PLL 11 is provided in the block diagram of the information reproducing apparatus in FIG. 10, separate PLLs may be provided for the ID part and the data part.

Next, as a fourth embodiment, a case where a pattern which does not exist in the data part is used for the frame mark will be described. FIG. 11 shows a block diagram of the information reproducing apparatus in this case.

The block diagram of the information recording apparatus is the same as the block diagram of the information recording apparatus of the third embodiment, and the operation is I
This is the same except that the D addition circuit 24 and the frame mark addition circuit 4 add an ID mark and a frame mark of a pattern that does not exist in the data portion.

Regarding the operation of the information reproducing apparatus, the data section is subjected to (1, 7) RLL modulation, and the ID section is subjected to PE (Phase).
An example in which Encoding) modulation is applied will be described. FIG. 11 is a block diagram of the information reproducing apparatus.

When the (1, 7) RLL modulation is performed and the mark length recording is performed, the reversal interval of the reproduced waveform is from 2T to 8T.
There are 7 types. T is a channel clock for (1,7) RLL modulation. On the other hand, in PE modulation, there are only two types of reproduction waveform inversion intervals, so these are assigned to 3T and 6T, respectively. Furthermore, the pattern of 11T that does not exist in the data part and the ID part is used as a frame mark, and 12T, 1
A 2T continuous pattern is embedded in the ID mark.

When reproducing information recorded in such a pattern, the signal reproduced from the recording medium 6 first enters the reproduction processing circuit 10, is amplified, and is output. The signal output here enters the frame mark detection circuit 12 and the ID mark detection circuit 25.

Here, the two detection circuits perform detection using the clock of the crystal oscillator 30 without using the clock synchronized with the reproduction signal. This is because the pattern included in the mark is 11T and does not exist in the data part.
This is because if a pattern from T to 12T can be detected, it can be detected as a frame mark. Similarly, the ID mark can be detected.

The frame mark and the ID mark thus detected enter the data demodulation circuit 14 and the ID demodulation circuit 29, respectively. In the data demodulation circuit 14, the PLL 11
Demodulation is performed using a clock synchronized with the reproduced signal output from the crystal oscillator 30 in the ID modulation circuit 29.
Demodulation is performed using the clock of. This is because the PE-modulated signal has only two types of inversion intervals of 3T and 6T, so that it is possible to perform demodulation by regarding 2T to 4T as 3T and 5T to 7T as 6T.

As described above, by using a pattern that does not exist in the data portion for the ID mark and frame mark, the mark can be detected immediately after the jump or seek and before the PLL locks. Since the ID can be read quickly as a reference, the seek time can be shortened.

In the embodiment, (1, 7) RLL modulation and PE modulation have been described as an example, but it goes without saying that the invention is not limited to this.

It is needless to say that the block operating using the crystal oscillator 30 in FIG. 11 may be operated by the clock generated by the PLL 11.

Next, as a fifth embodiment, an effective gate forming circuit for opening a gate from the detected frame mark to the next frame mark and a circuit for forming an alternative signal when the frame mark is not detected. An information reproducing apparatus having both will be described. A block diagram of the information reproducing apparatus of the fifth embodiment of the present invention is shown in FIG.

The effective gate generation circuit 31 counts the clocks output from the PLL 11 with the frame mark detected by the frame mark detection circuit 12 as a reference, and determines the number of clocks before and after the place where the next frame mark should be detected. A frame mark effective gate having a width corresponding to a clock is created, and the frame mark detection circuit 1 is provided while the gate is closed.
The frame mark detected in 2 is regarded as a false detection and is erased. The operation of the circuits other than this is the same as that of the information reproducing apparatus of the first embodiment.

By thus forming an effective gate for the frame mark, erroneous detection of the frame mark can be eliminated and more reliable data demodulation can be performed.

In each of the first to fifth embodiments, the case where the information recording device and the information reproducing device are separately configured has been described as an example. However, it is the same.

Although various circuits have been described in the first to fifth embodiments, it is needless to say that a device formed by combining these circuits can operate similarly.

Next, a sixth embodiment of the present invention will be described with reference to the drawings. An optical disk will be described as a sixth embodiment. As shown in FIG. 2, the optical disc according to the sixth embodiment of the present invention has a sector structure in which one sector is composed of a plurality of equally divided frames, and frame marks are arranged at the head of the sector at regular intervals. It is an optical disc that has.

[0048]

As described above, according to the present invention, when recording information on a recording medium, a sector is divided into a plurality of frames, and a frame mark for identifying the beginning of the frame is provided at the beginning of each frame. By arranging and recording one or more frames in a sector as an ID section for recording a physical address on a recording medium and recording the remaining frames in the sector as a data section for recording data, reproduction is performed. At times, it becomes possible to more reliably detect the frame mark and create an alternative signal with a circuit configuration simpler than the conventional one. As a result, it is possible to prevent a data demodulation error due to the influence of the frame mark detection accuracy, and it is possible to perform highly reliable reproduction.

[Brief description of drawings]

FIG. 1 is a block diagram of an information recording apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a sector format when recorded by the information recording apparatus of the first embodiment.

FIG. 3 is a block diagram of an information reproducing apparatus according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a sector format when recording is performed by a conventional information recording apparatus.

FIG. 5 is a block diagram of a conventional information reproducing apparatus.

FIG. 6 is a block diagram of an information recording apparatus according to a second embodiment of the present invention.

FIG. 7 is a block diagram of an information reproducing apparatus according to a second embodiment of the present invention.

FIG. 8 is a diagram showing a sector format when recorded by the information recording apparatus of the second embodiment.

FIG. 9 is a block diagram of an information recording apparatus according to a third embodiment of the present invention.

FIG. 10 is a block diagram of an information reproducing apparatus according to a third embodiment of the present invention.

FIG. 11 is a block diagram of an information reproducing apparatus according to a fourth embodiment of the present invention.

FIG. 12 is a block diagram of an information reproducing apparatus according to a fifth embodiment of the present invention.

[Explanation of symbols]

 1 Input Data 2 ID Addition Circuit 3 Data Modulation Circuit 4 Frame Mark Addition Circuit 5 Recording Processing Circuit 6 Recording Medium 7 Frame Mark 8 ID 9 Data 10 Reproduction Processing Circuit 11 PLL 12 Frame Mark Detection Circuit 13 Rough Signal Creation Circuit 14 Data Demodulation Circuit 15 output data 16 sector mark detecting circuit 17 SYNC detecting circuit 18 RESYNC detecting circuit 19 SYNC alternative signal creating circuit 20 RESYNC alternative signal creating circuit 21 sector mark 22 SYNC 23 RESYNC 24 ID mark adding circuit 25 ID mark detecting circuit 26 ID decoding circuit 27 ID mark 28 ID modulation circuit 29 ID demodulation circuit 30 Crystal oscillator 31 Effective gate creation circuit

Claims (11)

[Claims] 1. A device for recording information on a recording medium having a sector structure, wherein the sector is equally divided into a plurality of frames, and a frame mark for identifying the beginning of the frame is provided at the beginning of each frame. Place 1 in the sector
One or a plurality of the frames are used as an ID section for recording a physical address on a recording medium, and the remaining frames in the sector are used as a data section for recording data, and the frame marks are arranged at regular intervals. An information recording device for recording. 2. The information recording apparatus according to claim 1, wherein an ID mark for identifying the ID portion is arranged after the frame mark. 3. The information recording apparatus according to claim 1, wherein the information recorded in the ID part and the information recorded in the data part are modulated by different modulation systems and recorded. 4. The information recording apparatus according to claim 1, wherein the frame mark arranged for identifying the head of the frame is formed by a pattern which does not exist in the data section. 5. A frame mark for identifying the head of each frame is arranged at the head of the frame, and an ID section representing a physical address on a recording medium consisting of one or a plurality of the frames, and a plurality of ID sections. A device for reproducing information from a recording medium in which the frame mark is recorded at a constant interval in a sector structure that forms one sector with a data section made up of a plurality of frames, and the frame mark is reproduced from a reproduction signal. An information reproducing apparatus, characterized in that it has a means for detecting a signal and a means for demodulating data with the detected frame mark as a reference. 6. A means for detecting an ID mark for identifying an ID portion from a reproduction signal, and a means for forming a gate for the ID mark based on a frame mark detected from the reproduction signal. 6. The information reproducing apparatus according to claim 5, further comprising means for decoding the ID on the basis of the ID mark. 7. The information reproducing apparatus according to claim 5, further comprising means for demodulating the ID section and means for demodulating data separately. 8. An information reproducing apparatus according to claim 5, further comprising means for detecting a frame mark for identifying a head of a frame without using a clock synchronized with a reproduced signal. 9. The information reproducing apparatus according to claim 5, further comprising means for generating an alternative signal from the previously detected frame mark when the frame mark cannot be detected from the reproduced signal. 10. The information reproducing apparatus according to claim 5, further comprising means for forming a gate for the next frame mark based on a frame mark detected from a reproduction signal. 11. A frame mark for identifying the beginning of each frame is arranged at the beginning of the frame, and an ID portion representing a physical address on the optical disc consisting of one or a plurality of the frames, and a plurality of ID portions. 2. An optical disc in which the frame mark is recorded at a constant interval in a sector structure that forms one sector with the data section consisting of the frame.