JP2770882B2 - Information recording / reproducing apparatus and access method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an information recording / reproducing apparatus and an access method for recording and / or reproducing information on a recording medium having a recording surface divided into a plurality of zones. It is.

[Prior Art] In an optical disc, a plurality of tracks are concentric or
It is provided in a spiral shape. Each track is divided into a plurality of sectors in order to record variable-length data and to speed up access, and recording or reproduction is performed in sector units. Recording of information is performed by converging laser light emitted from a semiconductor laser on a recording layer on a disk and forming holes in the recording layer or by changing the reflectance and transmittance to form recording pits. .

Data recording methods are broadly classified into two types: a CLV method in which the recording pits are recorded on a disk at a constant linear velocity, and a CAV method in which the recording pits are recorded at a constant angular velocity. In the CAV method, since recording is performed at a constant angular velocity, the data recording density per unit length is lower at the outer peripheral portion of the disk than at the inner peripheral portion, and is inferior in terms of efficient use of storage capacity. Also, in the CLV method, since sectors do not become radial, and the number of revolutions differs depending on the position, data cannot be reproduced until the number of revolutions of the disk reaches the target value at the time of access, and the access time becomes longer. There is.

The MCAV system, which has both the easy access of the CAV system and the advantage of the recording density of the CLV system, is disclosed in
It is proposed in, for example, Japanese Patent Publication No. 167874. In this method, a disc is divided into a plurality of concentric zones in the direction of the radius of rotation, and recording or reproduction is performed by rotating the disc at a constant angular velocity within the same zone and at a lower angular velocity toward the outer zone. or,
As an MCAV method that provides the same effect, a method is known in which the number of rotations is constant, and the recording / reproducing frequency is increased as the distance from the outer zone increases.

On the other hand, in the information recording / reproducing apparatus using the above-mentioned optical disk, a track search mechanism is provided in order to record or reproduce in an arbitrary sector. Usually, such a track search is performed as follows. First, the index data (including the track address and the like) of the track currently scanned by the light beam is read. Then, the optical head is moved in a direction approaching the target track based on a difference between the address of the target track and the read track address. Then, the track address of the destination track is read out. If this does not match the address of the target track, the optical head is moved again or the light beam is traversed by the lens actuator built in the optical head. In the direction (so-called kick). Then, the destination track address is confirmed, and the above operation is repeated until the track addresses match.

[Problems to be Solved by the Invention] However, the information recording / reproducing apparatus as described above has MCAV
When the method is applied, the following inconveniences occur. That is, upon receiving a command to access 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, the reading of the index data is started as described above.
However, if the destination track belongs to a zone different from the target track, the index data cannot be read because the angular velocity for reading is different. Then, the device is in a state where it cannot proceed to the previous operation, that is, a so-called deadlock occurs. Such a problem similarly occurs in the MCAV system in which the recording / reproducing frequency differs for each zone.

[Means for Solving the Problems] An object of the present invention is to solve the above-mentioned problems of the prior art, and to prevent information from being deadlocked even when a head accesses a zone different from a target track. An object of the present invention is to provide a recording / reproducing device and an access method.

The object as described above is that the recording surface is divided into a plurality of zones in the radial direction, each zone includes a plurality of tracks, and these tracks have a disk-shaped recording medium on which addresses are recorded at different angular velocities or frequencies depending on the zones. In an apparatus that performs at least one of recording and reproduction of information,
Command means for issuing a command indicating an angular velocity or frequency corresponding to a zone to which a target track belongs, a head which scans the track and performs at least one of recording and reproduction of information; and a command from the command means. Address detecting means for detecting an address of a track being scanned by the head based on the detected angular velocity or frequency; moving means for moving the head from the track currently being scanned to another track; and the moving means The head is moved toward the target track, and the address of the destination track is detected by the address detection means based on the angular velocity or frequency commanded by the command means. Access method that terminates the access if When accessing, the head erroneously moves to a track in a zone different from the zone to which the target track belongs, and the angular velocity or frequency instructed by the instruction means and the angular velocity of the address recorded in the destination track Or, if the address of this track cannot be detected due to a difference from the frequency, control means for moving the head toward another zone by a moving means is provided. You.

Further, an object of the present invention is to provide a disk-shaped recording device in which a recording surface is divided into a plurality of zones in a radial direction, each zone includes a plurality of tracks, and addresses are recorded on these tracks at different angular speeds or frequencies depending on the zones. A method for causing a head to access a target track in order to perform at least one of recording and reproduction of information on a medium, comprising: (a) issuing a command indicating an angular velocity or a frequency corresponding to a zone to which the target track belongs; (D) moving the head from the track currently being scanned toward the target track; (c) detecting the address of the track to which the head is moved based on a commanded angular velocity or frequency; ) If it is confirmed that the destination track matches the target track based on the detected address, (E) a step of continuing access if the destination track does not match the target track; and (f) a zone to which the head erroneously belongs to the target track at the time of access. Move to a track in a zone different from that of the head, and if the address of this track cannot be detected due to the difference between the commanded angular velocity or frequency and the angular velocity or frequency of the address recorded on the destination track, the head is moved. Moving to another zone.

[Operation] According to the present invention, after the head is moved, if the index data cannot be detected, the head is moved again to another track, so that even if the head is erroneously moved to another zone. By moving the head toward the target track again, deadlock of the device itself can be prevented, and as a result, the throughput of the entire system can be improved.

Embodiment FIG. 1 is a block diagram showing an embodiment of the information recording / reproducing apparatus of the present invention. In the figure, first, the basic operation of each unit will be described.

The main control circuit 1 sends write data from the host device 9 to the modulation circuit 2 and instructs the drive control circuit 4 on the track address of the write destination. The drive control circuit 4 instructs the optical disk device 5 to move the optical head to the write-destination track, and after receiving status information from the optical disk device 5 indicating that tracking has been performed, the index data in the drive control circuit 4. (I
D) Operate the confirmation counter 41 and wait for detection data from the sector mark detection circuit 6 and the ID detection circuit 7.

The sector mark detection circuit 6 detects a sector mark from the reproduced data from the optical disk device 5 and, if detected, detects an ID detection circuit 7, a synchronization circuit 8, a drive control circuit 4,
The effect is transmitted to the modulation circuits 2 respectively. ID detection circuit 7,
After detecting the sector mark, the synchronization circuit 8 sends the pre-formatted ID data and the synchronization pulse on the optical disk to the drive control circuit 4 and the demodulation circuit 3, respectively. The demodulation circuit 3 receives the data sent from the optical disk device 5 and
The ID data sent from the ID detection circuit 7 is transmitted to the synchronization circuit 8
The data is demodulated using the synchronization pulse sent from the controller 1 and each data is sent to the main control circuit 1.

After receiving the detection data from the sector mark detection circuit 6, the modulation circuit 2 sends the modulated data to the optical disk device 5. At this time, the modulation circuit 2 sends data after receiving the write command from the main control circuit 1. Also, the modulation circuit 2
May be configured to send data after a certain time after detecting the sector mark.

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

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

FIG. 2 is a schematic diagram showing a specific configuration example of the optical disk device shown in FIGS. In FIG.
Is rotated by a spindle motor 11. The spindle motor 11 rotates at an angular velocity corresponding to the zone to which the target track belongs in accordance with a command from the drive control circuit 4 described above.

Recording or reproduction of information on the optical disk 10 is performed by the optical head 12.
Done by This optical head 12 is a linear motor
The optical disk 10 is moved in the radial direction by the optical disk 13. Then, the linear motor 13 is controlled by the drive control circuit 4. The optical head 12 has a built-in semiconductor laser. The semiconductor laser 14 emits a light beam according to the signal input from the modulation circuit 2 described above. The light beam emitted from the semiconductor laser 14 passes through a collimator lens 15 and a beam splitter 16 and passes through an objective lens 17 to the optical disk 10.
Focused on top.

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. Photo detector
20 reproduces data based on the received reflected light and sends the 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 the tracking signal, the objective lens 17 is moved in the disk radial direction by the lens actuator 18 to perform auto tracking. At the time of track access (seek), the tracking control circuit 21 sends a pulse signal to the lens actuator 18 based on a command from the drive control circuit 4,
The kick operation described above is performed.

FIG. 3 is a flowchart showing a track access operation in the above device. FIG. 4 is a schematic plan view of the optical disk for explaining the track access operation. In FIG. 4, the black square points are the optical head,
A, B and E are tracks in the first zone 22, respectively, C
Indicates a track in the prohibited area 23, and D indicates a track in the second zone 24.

Next, the track access method according to the present invention will be described in detail with reference to FIGS.

In FIG. 4, when the head located on the A track in the first zone 22 is moved on the B track in the same zone, the head is moved by a seek by a rough search (step S1 in FIG. 3). However, since this seek operation has a seek error, it is not always possible to accurately reach a desired track.

After tracking is taken there (YE in step S2)
S), the ID recognition counter (41 in FIG. 1) is operated (step S3), and the sector mark and ID are read (step S3).
Four). If a sector mark is detected (YE in step S5)
S), reset the ID confirmation counter (step S9),
The seek operation ends as a result of seeking to the desired B track.

However, when the head 40 moves on the track C in the prohibited area 23 or on the track D in the second zone 24 due to the tracking loss due to the defect 40 shown in FIG. Cannot be read, so steps S4 to S7 are repeated. When this loop continues for the time required for the head to scan one track, the counter is over (YES in step S7), the head is moved to the first zone 22, and the seek to the track B is performed again. (Step S8) Also, if the tracking error occurs again during the operation of steps S4 to S7 (Yes in step S6), the counter is reset and the tracking is pulled into the destination track again (step S8). Step S2).

FIG. 5 is a flowchart showing a modification of the above-described track access method. This flowchart is the third
Step S8 in the flowcharts shown in the drawings can be replaced.

In step S7 shown in FIG. 3, when the count is over, the process proceeds to step 10 in this embodiment. Here, t indicates, for example, the frequency of head movement counted in the main control circuit 1, and 1 is input in advance before step S1 in FIG. m is a predetermined number and is set to the limit value of the retry of the track movement in the normal operation. That is, when the number of track movements reaches m,
It is determined that the device is not operating normally, an error message is displayed in step S15, and the operation ends.

If the number of retries has not reached m in step S10 (NO), the process proceeds to step S11. If the retry is the first retry in step S11 (NO), the process proceeds to step S12. Then, the head is moved in a direction away from the zone closer to the zone where the target track exists. This is to further increase the probability that the direction of movement will be toward the target track. This will be described with reference to FIG.

FIG. 6 is a schematic plan view of an optical disc recorded by the MCAV method. Here, the recording surface of the optical disk 10 is divided into zones 27, 28, and 29. If the target track for the track access is the track 25 in the zone 28, the optical head is likely to erroneously access the track in the zone 29. Therefore, if the ID of the destination cannot be read, the head is moved in a direction away from the zone 29 closer to the track 25, that is, in the direction a. When the target track is the track 26, the head is moved in the direction away from the zone 27, that is, in the direction b.

After moving the head in step S12, step S13
The frequency t is counted up at the step shown in FIG.
Return to S2. If the ID cannot be read again, the process proceeds to step S11 via steps S7 and S10. At this time, since the frequency t is 2 (YES), the process proceeds to step S14. In step S14, the head is moved in a direction opposite to the previous movement. After head movement, step S13
The frequency is counted up with and returns to step S2. Thus, the above operation is repeated until the ID can be read or the frequency t reaches m.

The present invention can be applied to various applications other than the embodiment described above.

For example, in FIG. 4, when the defect 40 is located near the center of the first zone 22 or the like, a track jump is performed from outside or inside the zone to the defect 40 to recognize the size of the defect 40, and the size of the defect 40 is recognized. That fact can also be recorded.

Of course, the effect of the present invention can be obtained even if the same processing is performed using the timer of the main control circuit 1 without providing the ID confirmation counter 41 on the circuit.

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

[Effects of the Invention] As described above, according to the present invention, after the head is moved, if the index data cannot be detected, the head is moved again toward another track. This has the effect of preventing deadlock and improving the throughput of the entire system.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing one configuration example of the information recording / reproducing apparatus of the present invention. FIG. 2 is a schematic diagram showing a specific configuration example of the optical disk device shown in FIGS. FIG. 3 is a flowchart for explaining one embodiment of the access method of the present invention. FIG. 4 shows a disk format of an optical disk medium according to an embodiment of the present invention. FIG. 5 is a flowchart showing a modification of the access method of the present invention. FIG. 6 is a schematic plan view of the optical disc for explaining the operation shown in FIG. 1: main control circuit, 2: modulation circuit, 3: demodulation circuit, 4: drive control circuit, 5: optical disk drive, 6: sector mark detection circuit,
7: ID detection circuit, 8: Synchronization circuit, 9: Host device, 41: ID confirmation counter.

Claims (7)

(57) [Claims] A recording surface is divided into a plurality of zones in a radial direction, each zone includes a plurality of tracks, and these tracks are recorded on a disk-shaped recording medium on which addresses are recorded at different angular velocities or frequencies depending on the zones. In an apparatus for performing at least one of recording and reproduction of information, command means for issuing a command indicating an angular velocity or a frequency corresponding to a zone to which a target track belongs among the tracks, and scanning on the track to record and reproduce information. A head that performs at least one of the following; an address detection unit that detects an address of a track that is being scanned by the head based on an angular velocity or a frequency that is instructed from the instruction unit; and a track that is currently scanning the head. Moving means for moving to another track; and the moving means for directing the head to a target track. Then, based on the angular velocity or frequency commanded by the command means, the address detection means detects the address of the destination track. If the destination track matches the target track, the access is terminated. Access means for continuing access if not performed, and at the time of access, the head erroneously moves to a track in a zone different from the zone to which the target track belongs, and the angular velocity or frequency commanded by the command means. And control means for moving the head toward another zone by moving means if the address of the track cannot be detected due to a difference between the angular velocity or the frequency of the address recorded on the destination track. An information recording / reproducing apparatus characterized by the above-mentioned. 2. The control means moves the head away from a zone closer to a target track among zones adjacent to a zone where a target track exists, if an address cannot be detected. An information recording / reproducing apparatus according to claim 1. 3. The control means, after moving the head toward another zone, if the address cannot be detected even in the track after the movement, moves the head again in the direction opposite to the previous movement. The information recording / reproducing apparatus according to claim 1, which is moved. 4. A disk-shaped recording medium having a recording surface divided into a plurality of zones in a radial direction, each zone including a plurality of tracks, each of which has an address recorded at a different angular velocity or frequency depending on the zone. A method for causing a head to access a target track to perform at least one of recording and reproduction of information, comprising: (a) issuing a command indicating an angular velocity or a frequency corresponding to a zone to which the target track belongs; (b) the head (C) detecting the address of the track to which the head moves based on the commanded angular velocity or frequency; (d) detecting the address of the track to which the head is moved based on the commanded angular velocity or frequency. If it is confirmed based on the address that the destination track matches the target track, the access is terminated. (E) the step of continuing access when the destination track and the target track do not match; and (f) the zone where the head erroneously belongs to the target track at the time of access. If the head is moved to a track in a different zone and the address of this track cannot be detected due to the difference between the commanded angular velocity or frequency and the angular velocity or frequency of the address recorded on the destination track, the head is replaced by another head. Moving the vehicle toward the zone. 5. The head according to claim 4, wherein, in the step (f), the head is moved away from a zone closer to the target track among zones adjacent to a zone to which the target track belongs. Access method. 6. The access method according to claim 4, wherein the steps (c) and (f) are repeated until an address can be detected. 7. The access method according to claim 6, wherein, when the step (f) is performed again by repetition, the head is moved in a direction opposite to the previous movement.