JPH0643866U - Optical disc and optical disc device - Google Patents

Abstract

(57) [Summary] [Purpose] Track number (TN) and sector number (S)
Even if there is an error in either one of N), the number with no error can be detected. An optical disc of the present invention has a plurality of tracks, the tracks are divided into a plurality of sectors, and each of the sectors has a TN and a first error detection code for detecting an error of the TN. And an SN and a second error detecting code for detecting the error detecting code of the SN are recorded. With such a configuration, when performing recording / reproducing with respect to the optical disc in the optical disc device, the T
The N error detection can be detected by the first error detection code, and the SN error detection can be detected by the second error detection code. Therefore, even if either TN or SN has an error,
The other can be detected.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an optical disc recording / reproducing apparatus using an optical disc.

[0002]

[Prior art]

 A conventional optical disc of this type has a structure as shown in FIG. In FIG. 6, tracks 16 are engraved on the disk 15. In FIG. 6, only tracks engraved on the inner circumference are shown for the sake of simplicity, but in reality, the tracks 16 are engraved to the outer peripheral side of the disk 15. The track 16 has one track for one round of the disk, and each track is given a unique track number as described later. Further, in FIG. 6, the track 16 is engraved in a spiral shape, but it may be engraved in a concentric shape.

FIG. 7 is a diagram showing a format in a track. The track 16 is divided into a plurality of sectors as shown in FIG. 7, and each sector is divided into an SM section, an ID section and a DATA section. The SM section is an area indicating the beginning of a sector, and the DATA section is an area for writing user data. The ID section is further divided into a VFO section, an AM section, a TN section, an SN section and a CRC section. The AM section is an area indicating the read start position of the code data. The TN section is an area showing a track number (hereinafter referred to as TN), and the SN section is a area showing a sector number (hereinafter referred to as SN). The VFO section is an area in which a continuous repetitive pattern for surely reproducing TN and SN is recorded even if the rotation of the disk changes. The CRC section is an area in which an error detection code CRC (Cycle Redundancy Check) for detecting whether or not the read address is correct is recorded.

An optical disc apparatus for recording or reproducing data on such a disc moves a head to seek a desired track, reproduces a sector in the track, and The TN and SN are read from the ID section to access the target sector, and the data is read and written from the sector.

[0005]

[Problems to be solved by the device]

 In the conventional technique as described above, if there is an error in either the read TN or SN, both TN and SN cannot be detected. This is because the error detection of TN and SN is detected by one CRC recorded in the CRC section. Therefore, it is an object of the present invention to provide an optical disc and an optical disc device that can detect the error-free number even if one of the track number (TN) and the sector number (SN) has an error.

[0006]

[Means for Solving the Problems]

 In order to solve the above problems, the optical disc of the present invention has a plurality of tracks, the tracks are divided into a plurality of sectors, and a track number and an error of the track number are detected in each of the sectors. The first error detection code, the sector number, and the second error detection code for detecting the error detection code of the sector number are recorded.

In addition, the optical disk device of the present invention has “a plurality of tracks, the tracks are divided into a plurality of sectors, and a track number and an error of the track number are detected in each of the sectors. Of the optical disc recorded with the first error detection code, the sector number, and the second error detection code for detecting the error detection code of the sector number. , A track number detection circuit for inputting the reproduction signal and the track number and the first error detection code, and the reproduction signal for inputting the sector number and the second error signal. A sector number detection circuit for detecting an error detection code is provided.

[0008]

[Action]

 In the present invention, since the detection of the error of the track number can be detected by the first error detection code and the detection of the error of the sector number can be detected by the second error detection code, either the track number or the sector number can be detected. Even if there is an error in one, the other can be detected.

[0009]

【Example】

 FIG. 1 is a diagram showing a sector format of an optical disc according to a first embodiment of the present invention. Also in this embodiment, the track is carved on the optical disk and the track is divided into a plurality of sectors, as in the conventional optical disk. In FIG. 1, each sector is divided into an SM section, an ID section and a DATA section. Up to this point, the process is the same as in FIG. 7. The ID section is further divided into a VFO section, an AM section, a TN section, an SN section, and two CRC sections. A CRC1 part is provided after the TN part, and a CRC2 part is provided after the SN part. An error detection code (CRC1) for detecting a read TN error is recorded in the CRC1 section, and an error detection code (CRC2) for detecting a read SN error in the CRC2 section. Is recorded. That is, two error detection codes for TN and SN error detection are provided independently.

FIG. 2 is a block diagram of an optical disk device for recording or reproducing information on the optical disk according to the first embodiment of the present invention. The optical disc 1 is the optical disc of the first embodiment described above, and has tracks 2 engraved on it. The optical disc 1 is rotationally driven by a spin drum motor (not shown). The head 3 irradiates a track of the optical disc 1 with laser light, receives the reflected light, converts it into an electric signal, and outputs it. The head 3 can be moved in the radial direction of the optical disc 1 by a control signal from the servo circuit 11. The signal read from the disk 1 by the head 3 is amplified by the main amplifier 4 and converted into 1 and 0 signals (binary signal) by the binarizing circuit 5. This binary signal is output to the VFO circuit 14. The VFO circuit 14 is for taking out a clock (synchronous clock) synchronized with the binary signal, and produces a synchronous clock by the signal pattern read from the VFO section in the sector. The binary signal from the binarization circuit 5 and the synchronous clock from the VFO circuit 14 are input to the AM detection circuit 6, the TN detection circuit 7, the SN detection circuit 8 and the DATA read circuit 9.

The AM detection circuit 6 detects an address mark (AM) from the binary signal and outputs a detection signal. The detection signal from the AM detection circuit 6 is input to the TN detection circuit 7 and the SN detection circuit 8. The TN detection circuit 7 and the SN detection circuit 8 respectively detect TN and CRC1 and SN and CRC2 from the binary signal by using the detection signal as a trigger.

The TN detection circuit 7 detects an error in the read TN by the CRC 1, and outputs the TN to the control circuit 10 if there is no error. Further, the SN detection circuit 8 detects the error of the read SN by the CRC2, and outputs the SN to the control circuit 10 if there is no error. The DATA read circuit 9 uses the signal from the control circuit 10 as a trigger to detect and output the signal read from the DATA section of the sector using a binary signal.

The control circuit 10 inputs the TN from the TN detection circuit 7 and the SN from the SN detection circuit 8, and the seek operation of the head 3 by the servo circuit 11 and the DATA read circuit 9 are performed. The detection of the signal read from the DATA section of the sector is controlled. The servo circuit 11 controls the head 3 to move to a designated track based on a control signal from the control circuit 10.

At the time of seeking, the track number of the track to be sought is designated by a controller (not shown) or the like and set in the control circuit 10. If the TN detected by the TN detection circuit 7 does not match the track number of the designated track, the control circuit 10 outputs a control signal to the servo circuit 11 to move the head 3 to the designated track. Let In the seek operation as described above, if the TN detected by the TN detection circuit 7 matches the track number of the specified track, it means that the head 3 has come to the specified track, and the seek is performed. Has been completed. In such a seek operation, the TN in the reproduced signal is detected and compared with the track number of the designated track. Therefore, it is important to detect the TN by the TN detection circuit 7. However, the seek operation is possible even if the SN cannot be detected. In other words, even if the SN detection circuit 8 detects an error in the read SN and SN is not output to the control circuit 10, if the TN detection circuit 7 correctly detects TN, the specified track The head 3 can be moved.

Next, after the head 3 moves to the designated track, the head 3 is made to follow the track. This tracking control can be realized by using the servo circuit 11 by a known tracking servo technique. Then, the ID portion of the sector in the track being followed is sequentially read to search for the designated sector. At this time, since the SN in the read reproduced signal is compared with the designated sector number, it is important for the SN detection circuit 8 to detect the SN. However, since it continues to follow a predetermined track, the track number is known and the sector can be searched even if TN cannot be detected. That is, even if an error is detected in the read TN in the TN detection circuit 7 and TN is not output to the control circuit 10, if the SN is correctly detected in the SN detection circuit 7, the designated sector Can be searched for. Once the specified sector has been located (ie, the head is at the specified sector), the data can be read from the DATA portion of that sector.

FIG. 3 is a diagram showing a sector format of an optical disc according to a second embodiment of the present invention. An AM1 section is provided in front of the TN section, and an AM2 section is provided in front of the SN section. That is, an address mark for detecting TN and SN is provided independently. FIG. 4 is a block diagram of an optical disk device for recording or reproducing information on the optical disk according to the second embodiment of the present invention. Those given the same reference numerals as those in FIG. 2 are the same as those in FIG. The AM1 detection circuit 12 detects AM1 from the binary signal and outputs a detection signal. Further, the AM2 detection circuit 13 detects AM2 from the binary signal and outputs a detection signal.

In the above-described first embodiment, the TN detection circuit 7 detects the TN and the SN detection circuit 8 detects the SN by using the AM detection signal from the AM detection circuit 6 as a trigger. Therefore, if AM cannot be detected, TN and SN cannot be detected. Therefore, in the present embodiment, the TN detection circuit 7 detects TN using the AM1 detection circuit 12's AM1 detection signal as a trigger, and the SN detection circuit 7's SN detection uses the AM2 detection circuit 13's AM2 detection signal. We decided to do it as a trigger.

With the above configuration, SN can be detected if AM2 can be detected even if AM1 cannot be detected, and TN can be detected if AM1 can be detected even if AM2 cannot be detected. It will be possible. Further, even if a bit slip due to a medium defect or the like occurs during TN detection, SN can be detected by detecting AM2.

FIG. 5 is a diagram showing a sector format of an optical disc according to a third embodiment of the present invention. The VFO1 section is provided in front of the AM1 section, and the VFO2 section is provided in front of the AM2 section. That is, a VFO section for producing a synchronous clock for AM1 or TN detection and a VFO section for producing a synchronous clock for AM2 or SN detection are independently provided.

In the above-described first or second embodiment, when the signal pattern of the VFO portion cannot be read normally due to the medium defect in the VFO portion, the VFO circuit 14 generates the synchronous clock. As a result, the AM, TN, SN, etc. after that cannot be read. According to this embodiment, even if the VFO1 section is not normally read and synchronization is not achieved, the VFO2 section reads the synchronization clock again to detect the AM2, SN, etc. after the VFO2 section. be able to. Further, even if the VFO2 section cannot be read normally, if the VFO1 section is read, AM 1, TN, etc. can be detected. The effect when one of SN and TN cannot be detected but the other one can be detected is the same as in the first and second embodiments.

[0021]

[Effect of device]

 As described above, according to the present invention, if one of the track number and the sector number has an error, the other can be detected, so the track number of a certain sector is detected once while following a certain track. For example, even if the track number of the sector to be read later has an error and cannot be detected, if the sector number can be detected, the desired sector can be searched for and the data can be read from that sector.

Further, when the target track is searched, there is an effect that the target track can be searched if the track number can be detected even if the sector number cannot be detected.

[Brief description of drawings]

FIG. 1 is a diagram showing a format of an optical disc according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of an optical disc device that records and reproduces information on the optical disc of FIG.

FIG. 3 is a diagram showing a format of an optical disc according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of an optical disc device that records and reproduces information on the optical disc of FIG.

FIG. 5 is a diagram showing a format of an optical disc according to a third embodiment of the present invention.

FIG. 6 is a diagram showing a conventional optical disc.

FIG. 7 is a diagram showing a format of a conventional optical disc.

[Explanation of symbols]

 1 optical disk 2 track 3 head 5 binarization circuit 7 track number detection circuit 8 sector number detection circuit

Claims (2)

[Scope of utility model registration request] 1. A plurality of tracks, the tracks are divided into a plurality of sectors, and a track number and a first error detection code for detecting an error of the track number are provided in each of the sectors. An optical disc having a sector number and a second error detection code for detecting an error detection code of the sector number recorded therein. 2. A plurality of tracks, the tracks are divided into a plurality of sectors, and a track number and a first error detection code for detecting an error of the track number are provided in each of the sectors. A head for reading a signal recorded in the sector of the optical disc on which a sector number and a second error detection code for detecting an error detection code of the sector number are recorded and outputting a reproduction signal, and the reproduction signal. Enter the track number and the first
2. An optical disk device comprising: a track number detecting circuit for detecting the error detecting code, and a sector number detecting circuit for inputting the reproduction signal and detecting the sector number and the second error detecting code.