JPH02289978A - Information recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent a deadlock and to promote the throughput of a system in total by deciding that a head is positioned in a different zone from a zone which an objective track belongs to when an index data of a track of destination cannot be detected and moving the head to other track again. CONSTITUTION:For example, when the head positioned on a track A in a zone 22 is moved to a track B in the same zone, and if the index data of the track B cannot be detected, the head is moved again toward the objective track B by deciding that the head is positioned in different zones 23 and 24 from the zone 22 which the track B belongs to. Consequently, even when the head is erroneously moved to the other zones 23 and 24, the head can be moved again to the objective track. By this method, a deadlock is prevented, and the throughput of the whole system can be promoted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an information recording and reproducing apparatus that records and/or reproduces information on a recording medium whose recording surface is divided into a plurality of zones.

[Prior Art] An optical disc has a plurality of tracks arranged concentrically or spirally. In order to record variable length data and to speed up access, each track is divided into a plurality of sectors, and recording or reproduction is performed sector by sector. Information is recorded by focusing laser light emitted from a semiconductor laser onto the recording layer on the disk, and forming recording pits by punching holes in the recording layer or changing reflectance and transmittance. .

Data recording methods are roughly divided into two types: the CLV method, in which recording bits are recorded on a disk at a constant linear velocity, and the CAV method, in which recording bits are recorded at a constant angular velocity. CA
In the V method, since data is recorded at a constant angular velocity, the outer circumference of the disk has a lower data recording density per unit length than the inner circumference, and is inferior in terms of efficient use of storage capacity. or,
In the CLV method, sectors are not radial, and
Since the rotation speed varies depending on the position, data cannot be reproduced until the disk rotation speed reaches a target value during access, resulting in a long access time.

Therefore, the MCAV system or Japanese Patent Laid-Open No. 167874/1983 has been proposed, which has both the easy access of the CAV system and the advantages of the recording density of the CLV system. In this method, a disk is divided into a plurality of concentric zones in the direction of the rotation radius, and recording or reproduction is performed by rotating the disk at a constant angular velocity within the zone and a lower angular velocity toward the outer zone. Furthermore, as an MCAV method that provides similar effects, a method is known in which recording or reproduction is performed by keeping the rotational speed constant and increasing the recording/reproducing frequency toward the outer zone.

On the other hand, in the information recording/reproducing apparatus using the optical disc, a track search mechanism is provided in order to perform recording or reproduction in an arbitrary sector.

Usually, such a track search is performed as follows. First, the index data (including 1 to rack address, etc.) of the track currently being scanned by the light beam is read out. Then, based on the difference between the address of the target track and the read track address, the optical head is moved in a direction closer to the target track. Then read the track address of the destination track, and if this does not match the address of the destination track,
The optical head is moved again, or the optical head is moved in a direction across the track (so-called kicking) using a lens actuator built into the optical head. Then, the destination track address is confirmed, and the above operation is repeated until the track addresses match.

[Problem to be solved by the invention] However, in the information recording and reproducing device as described above, the MCA
When the V method is applied, the following disadvantages occur.

That is, upon receiving an access command to the target track, the apparatus first rotates the disk at the angular velocity of the zone to which the target track belongs. Then, after moving the optical head,
Reading of index data is started as described above.

However, if the destination track belongs to a different zone from the target track, the index data cannot be read out because the angular velocity for reading is different. Then, the device falls into a state where it cannot proceed to the next operation, a so-called deadlock. Such a problem also occurred in the MCAV system in which the recording/reproducing frequency is varied for each zone.

[Thousand Steps to Solve the Problems] The purpose of the present invention is to solve the above-mentioned problems of the prior art, and to prevent deadlock even when the head accesses a zone different from the target track. An object of the present invention is to provide an information recording and reproducing device.

The following objectives are to divide a recording medium into a plurality of zones each including a plurality of tracks, and to record and reproduce information at a constant angular velocity or recording/playback frequency in each zone, but different in different zones. /or a reproducing head;
means for moving the head toward a target track;
In an information recording/reproducing apparatus equipped with means for identifying index data of a track to which the head is moving, if the index data of the track to which the head is moving cannot be detected, the head is in a zone different from the zone to which the target track belongs. This is achieved by an information recording/reproducing apparatus characterized in that the head is moved toward another track again when the head is determined to be on the other track.

[Function] According to the present invention, if index data cannot be detected after the head has moved, the head is moved again towards another track, and if the head is moved to another zone by mistake, However, it is also possible to move the head toward the target track again, thereby preventing deadlock of the device itself, and as a result, it is possible to improve the throughput of the entire system.

[Embodiment] FIG. 1 is a block diagram showing an embodiment of an information recording/reproducing apparatus of the present invention. In the figure, first, the basic functions of each part will be explained.

The main control circuit 1 sends the write data from the host device 9 to the modulation circuit 2, and also instructs the drive control circuit 4 about the write destination track address. Drive control circuit 4
Instructs the optical disc device 5 to move the optical head to the write destination track, and after receiving status information from the optical disc device 5 indicating that tracking has started, the index data (ID
) Activate the confirmation counter 4l and wait for detection data from the sector mark detection circuit 6 and ID detection circuit 7.

The sector mark detection circuit 6 detects a sector mark from the reproduced data from the optical disc device 5, and if it is detected,
The ID detection circuit 7, the synchronization circuit 8, the drive control circuit 4, and the modulation circuit 2 are each notified of this fact. ID detection circuit 7,
After detecting the sector mark, the synchronization circuit 8 sends preformatted ID data on the optical disc and a synchronization pulse to the drive control circuit 4 and the demodulation circuit 3, respectively. The demodulation circuit 3 demodulates the data sent from the optical disk device 5 and the ID data sent from the ID detection circuit 7 using the synchronization pulse sent from the synchronization circuit 8, and sends each data to the main control circuit l. Send the data.

After receiving the detection data from the sector mark detection circuit 6, the modulation circuit 2 sends the modulated data to the optical disc device 5. At this time, the modulation circuit 2 sends data after receiving the write command from the main control circuit l. Furthermore, the modulation circuit 2 may be configured to send data after a certain period of time after sector mark detection.

The main control circuit 1 receives demodulated data from the demodulation circuit 3, sends the data to the host device 9, and uses the ID data for instructions to the drive control circuit 4 and modulation circuit 2. For example, if the target track is the target sector, the modulation circuit 2 is notified of this, and if it is not the target track, the target track address is instructed to the drive control circuit 4.

The ID confirmation counter 41 in the drive control circuit 4
Reset after receiving detection data.

FIG. 2 is a schematic diagram showing a specific example of the configuration of the optical disc device shown in FIG. 1. In Figure 2, the optical disk IO
is rotated by a spindle motor 11. This spindle motor l1 rotates at an angular velocity corresponding to the zone to which the target track belongs, in accordance with commands from the drive control circuit 4 described above.

Recording or reproduction of information on the optical disc 10 is performed using an optical head l.
This is done by 2. This optical head 12 is moved in the radial direction of the optical disc 10 by a linear motor l3. The linear motor l3 is driven by a drive control circuit 4.
controlled by The optical head l2 includes a semiconductor laser 1
It has 4 built-in. This semiconductor laser 14 emits a light beam in accordance with a signal input from the modulation circuit 2 described above. The light beam emitted from the semiconductor laser l4 passes through a collimator lens 15 and a beam splitter l6, and is focused onto the optical disc 10 by an objective lens 17.

The light beam reflected by the optical disk 10 passes through the objective lens 17 again, is deflected by the beam splitter 16, and is received by the photodetector 20 via the sensor lens 19.

The photodetector 20 reproduces data based on the received reflected light and sends this data to the demodulation circuit 3 described above. Further, the tracking control circuit 21 detects a tracking signal from the output signal of the photodetector 20. Then, in accordance with this tracking signal, the objective lens 17 is moved in the radial direction of the disk 1' by the lens actuator 18, thereby performing auto-tracking. Also, track access (
At the time of seek), the racking control circuit 21 sends a pulse {M number} to the lens actuator l8 based on a command from the drive control circuit 4 to cause it to perform the kicking operation described in 111j.

FIG. 3 is a flowchart showing the track access operation in the recording device. In addition, FIG. 4 shows a schematic 31 of an optical disk for explaining this 1. rack access operation.
It is a side view. In FIG. 4, the black square points are the optical head, Δ. B. F: indicates a track within the first zone 22, C indicates a track within the prohibited area 23, and D indicates a track within the second zone 24.

Next, the track access method in the apparatus of the present invention will be explained in detail with reference to FIGS. 3 and 4.

In FIG. 4, when moving the head located on A track 1- in the first zone 22 to the 13th track in the same zone, the head is moved by seek using a set search. Sl). L: Since there is a seek error in this seek operation, it is not always possible to go to the desired track, so after tragging is removed (YES in step S2). +D recognition counter (41 in Fig. 1) is operated (step S3>. sector mark and 11) is read (step S4). ．． If a sector mark is detected (YL=:S in step S5)
)． I1) The confirmation counter is reset (step S9), and the seek operation is terminated as it is assumed that the desired B{- rack has been sought.

However, due to the defect 40 shown in FIG. If this occurs, the sector mark cannot be read, and steps 84 to S7 are repeated. If this loop continues for the time it takes for the head to scan l1-rack, the counter will become one bar (step S7).
YES) The head is moved to the first zone 22 and a seek to the 13th track is performed again. (Step S8) Also, during the operation of steps 84 to S7, 1.
If the racking is removed too much (step 86)
Yes), reset the counter and TI1
Tragging is then pulled into the destination track (step S2).

FIG. 5 is a flow chart showing a modification of the track access method described in 111J. This flow-7-v
Step S8 of the flow chart shown in FIG. 73 can be replaced with step S8 of the flow chart shown in FIG.

In step S7 of the third figure, the count value is set to l((), and in this embodiment, the process moves to the sub-IO. Indicates the number of degrees of head movement, and the child 1 is manually operated at step SL 111 in Figure 3. m is a predetermined number, and When the limit value has been set, that is, the number of times the track movement has been repeated has reached m+3, it is determined that the device is not operating normally, and the process proceeds to step S.
15, an error message is displayed and the operation ends.

In step S10, if the number of retries has not reached m (No). Proceed to step Sll.

In step S11, if the retry is the first time (No), the process advances to step S12. Then, among the zones adjacent to the zone where the target track exists, the target track is moved further in the direction away from the closest zone. This is to increase the probability that the direction of movement will be toward the target track. This will be explained using FIG.

FIG. 6 is a schematic plan view of an optical disc recorded using the MCAV method. Here, the recording surface of the optical disc IO is divided into zones 27, 28, and 29. Track access target track or track 25 in zone 28
In this case, there is a high possibility that the optical head will access a track in zone 29 by mistake. Therefore, the destination ID
If the head cannot be read out, the head is moved in a direction away from the zone 29 that is closer to the track 25, that is, in the direction a. If the target track is the track 26, the head is moved in the direction away from the zone 27, that is, in the b direction.

After moving the head with SDEPP SI2,
At I3, the number of pardons is counted up, and the process returns to step S2 in FIG. If the ID cannot be read again, the process goes to step S11 via step S7 and step SIO. At this time, the degree is 2, so (
YF. S) Proceed to step SI4. Sudep S
In l4, the head is moved in the opposite direction to the previous movement. After the head is moved, the frequency is counted up in step S13, and the process returns to step S2. In this way, I.D.
The operation in -11 is repeated until it can be read or the frequency reaches m.

The present invention can be applied in various ways in addition to the embodiments described above.

For example, in FIG. 4, defect 40 is located in first zone 22.
If the defect 40 is located near the center of the zone, the child can make a track jump to the defect 40 from outside or inside the zone, recognize the size of the defect 40, and record the fact on the recording medium.

Further, as a matter of course, the effects of the present invention can be obtained even if the ID confirmation counter 41 is not provided in the circuit and the same processing is performed using the timer of the main control circuit 1.

Furthermore, although the example using an optical disk has been described in the second embodiment, the present invention is not limited to this, and can be applied to other information recording and/or reproducing apparatuses such as magnetic disks.

[Effects of the Invention] As explained above, according to the information recording and reproducing apparatus of the present invention, if index data cannot be detected after the head has moved, the head is moved again toward another track. This prevents the device from deadlocking itself,
This has the effect of improving the throughput of the entire system.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of the configuration of an information recording/reproducing apparatus according to the present invention. FIG. 2 is a schematic diagram showing a specific example of the configuration of the optical disc device shown in FIG. 1. FIG. 3 is a flowchart for explaining the operation in one embodiment of the present invention. FIG. 4 shows a disc format of an optical disc medium in an embodiment of the present invention. FIG. 5 is a flowchart showing a modification of the operation of the apparatus shown in FIG. 6 is a schematic plan view of the optical disc for explaining the operation shown in FIG. 5. FIG. 1: Main control circuit, 2: Modulation circuit, 3: Demodulation circuit, 4: Drive control circuit, 5: Optical disk device, 6: Sector mark detection circuit, 7: ID detection circuit, 8: Synchronization circuit, 9: Host device, 41: ID confirmation counter. Agent Patent Attorney Johei Yamashita

Claims (3)

[Claims] (1) A head that divides a recording medium into a plurality of zones each including a plurality of tracks, and records and/or reproduces information at a constant angular velocity or recording/reproducing frequency in each zone but different in different zones. , an information recording/reproducing apparatus comprising means for moving the head toward a target track and means for identifying index data of the track to which the head is moving, wherein the index data of the track to which the head is moving cannot be detected. If the head is located in a zone different from the zone to which the target track belongs, the head is determined to be in a zone different from the zone to which the target track belongs, and the head is moved again toward another track. (2) If the index data of the destination track cannot be detected, the head is moved in a direction away from a zone adjacent to the zone where the destination track exists. The information recording and reproducing device described in Section 1. (3) The information recording and reproducing apparatus according to claim 1, wherein if the index data of the destination track cannot be detected, the head is moved in the opposite direction to the previous movement.