JPH09219028A - Device and method for recording medium recording and reproducing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the seek time of the optical disk having plural information layers. SOLUTION: When a seek, which includes the movement between information layers of an optical disk 1, is conducted, a system controller 6 first executes the movement among the layers by a focus actuator 11 or the coarse seek by a thread servo motor 8. Then, a fine seek is conducted by a tracking actuator 12 and completes the seek.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium recording / reproducing apparatus and a recording medium recording / reproducing method, and more particularly to a recording medium recording / reproducing apparatus and recording medium for recording or reproducing information on a plurality of information layers of a recording medium. Recording / reproducing method.

[0002]

2. Description of the Related Art When recording or reproducing information on an optical disk, it becomes necessary to move (seek) a light beam to a predetermined position on the optical disk. The optical disk device
Usually, seek is realized by two seek methods. The first method is to move the position of the light beam by moving the objective lens, which is called dense seek. In this dense seek, only the objective lens having a small mass is directly moved by, for example, an actuator for tracking control, so that the light beam can be accurately moved, but the movable distance is limited (short).

The second method is a method of moving the entire optical system including the objective lens and the light source, which is called rough seek. This coarse seek indirectly moves the light beam by moving the entire optical system with a large mass in the radial direction of the optical disk by a seek motor or the like, so that the light beam cannot be moved accurately, but It is possible to move a long distance.

Various kinds of comprehensive seek methods combining these two methods have been proposed, but the following method is general.

FIG. 5 is a flow chart for explaining an example of processing of the conventional seek method. When the seek is started, the current position of the light beam on the optical disc is confirmed in step S1. Then, in step S2, it is determined whether or not the current position (address) of the light beam is equal to the target position (address). As a result, if it is determined that the current position of the light beam is equal to the target position, the process ends (seek end).

Further, the current position and the target position are different (N
O), the process proceeds to step S3, and a value obtained by subtracting the current position from the target position is larger than a threshold value (for example, a value determined based on a distance that can be moved by the dense seek). Is determined. As a result, when it is determined that the value obtained by subtracting the current position from the target position is larger than the threshold value (YES), the process proceeds to step S4, after performing the rough seek, the process returns to step S1 and the same process is repeated. If it is determined that the value obtained by subtracting the current position from the target position is smaller than the threshold value or they are equal to each other (NO), the process proceeds to step S5, after performing the dense seek, the process returns to step S1. The same process is repeated.

According to the above processing, when the seek distance is smaller than a predetermined threshold, only the dense seek is performed, and conversely, when the seek distance is larger than the threshold,
By repeating the coarse seek until the difference between the current position and the target position becomes smaller than the threshold value, and then performing the fine seek,
The light beam can be moved to the target position.

It should be noted that in some optical disk devices pursuing high performance, seek can be completed only by rough seek.
Although some coarse seeks have improved accuracy, in the present specification, coarse seek is defined as a method of moving a light beam having a large moving distance that does not require accuracy.

By the way, in recent years, in order to increase the storage capacity, it has two information layers (hereinafter abbreviated as "layers"),
For example, DVD (Digital Video Disk) (MMCD (Mu
ltimedia Compact Disk)) and other optical disks have been put to practical use. In such an optical disc, it is necessary to move (focus jump) the irradiation position of the light beam not only in the radial direction of the optical disc but also in the layer direction.

In the case of forming an optical disc having such two layers, the tracks of each layer are formed by different stampers at the time of disc production, and then pasting is performed, so that the tracks of each layer are in the same place. Are not formed, resulting in positional errors between the tracks of each layer. Therefore, when the irradiation position of the light beam is moved from the track of one layer (sector on the track) to the track of another layer (sector on the track), the track (or sector) before the movement and the track after the movement are moved. The tracks (or sectors) will shift in response to errors that occur during disk formation. That is, when an address is independently assigned to each layer, and a corresponding (same) address is assigned to a corresponding position of each layer, interlayer movement is performed from a predetermined address of a predetermined layer to another layer. At this time, the address of the track (sector on the track) of the layer after movement does not match the address of the track (sector on the track) of the layer before movement. Therefore, when moving between layers, it is necessary to perform seek processing in consideration of the error in the position originally included in the optical disc.

FIG. 6 is a flow chart for explaining an example of a conventional process for moving the irradiation position of a light beam in an optical disc having two information layers. When the seek is started, the current position in the current layer is confirmed in step S20. Then, in step S21, it is determined whether or not the current position (address) and the target position (address) are equal. As a result, if it is determined that the current position and the target position are different (NO), step S2
Proceed to 3.

In step S23, it is determined whether or not the value obtained by subtracting the current position from the target position is larger than the threshold value.
As a result, if it is determined that the value obtained by subtracting the current position from the target position is larger than the threshold value (YES), step S
After proceeding to 24 and performing a rough seek, the process returns to step S20 and the same processing is repeated. If it is determined in step S23 that the value obtained by subtracting the current position from the target position is smaller than the threshold value or they are equal to each other (NO), the process proceeds to step S25, and after performing a dense seek, The process returns to step S20 and the same processing is repeated.

On the other hand, if it is determined in step S21 that the current position is equal to the target position (YES) (after the irradiation position of the light beam reaches the target position in the same layer), the process proceeds to step S22. It is determined whether movement between layers is necessary. As a result, no movement between layers is required (N
If it is determined to be O), the process is ended (seek end).
If it is determined that movement between layers is necessary (YES), the process proceeds to step S26.

Then, in step S26, the movement of the light beam between the layers (movement from the current layer to the target layer) is performed. Then, in the following step S27, the current position in the layer after movement is confirmed, and further, in step S27.
At 28, it is determined whether the current position and the target position are equal.

If it is determined in step S28 that the current position and the target position are equal (YES), the process ends (seek end). If it is determined that the current position and the target position are not equal (NO), the process proceeds to step S29.

In step S29, it is determined whether or not the value obtained by subtracting the current position from the target position is larger than the threshold value.
As a result, if it is determined that the value obtained by subtracting the current position from the target position is larger than the threshold value (YES), after performing a rough seek in step S30, the process returns to step S27 and the same processing is repeated.

If it is determined in step S29 that the value obtained by subtracting the current position from the target position is smaller than the threshold value or they are equal to each other (NO), the process proceeds to step S31 to perform a dense seek. After that, the process returns to step S27 and the same processing is repeated.

[0018]

As described above, in the conventional seek method, the coarse seek and the dense seek are performed in the layer before the movement (the layer to which the light beam is currently irradiated) to perform the seek in the layer. After moving to the target position address (target position), interlayer movement is performed, and rough seek and fine seek are further performed in the moved layer (target layer) to move the light beam to the target address.

As described above, the tracks (sectors on the track) of each layer are displaced from each other due to an error in manufacturing an optical disk. It may be different from the layer track before moving. Therefore, since it is necessary to confirm the target address before and after the layer is moved, there is a problem that the seek time is extra.

The present invention has been made in view of the above circumstances, and enables high-speed seeking when recording or reproducing information on an optical disc having a plurality of information layers. It is a thing.

[0021]

According to another aspect of the present invention, there is provided a recording medium recording / reproducing apparatus combining a rough seek and a fine seek to perform a seek including a movement between a plurality of information layers from a current address to a target address. To check the target address,
It is characterized in that it is performed after moving between the information layers.

According to a seventh aspect of the present invention, there is provided a recording medium recording / reproducing method, wherein a target address is confirmed when a seek including a movement between a plurality of information layers from a current address to a target address is performed by combining a coarse seek and a fine seek. Is performed after moving between information layers.

In the recording medium recording / reproducing apparatus according to the first aspect, when the seek including the movement between the plurality of information layers from the current address to the target address is performed by combining the coarse seek and the fine seek, The confirmation is performed after moving between the information layers. For example, when moving from a certain sector of one information layer to a certain sector of another information layer, a dense seek is executed only once.

In a recording medium recording / reproducing method according to a seventh aspect of the present invention, when a seek including a movement between a plurality of information layers from a current address to a target address is performed by combining coarse seek and fine seek, The confirmation is performed after moving between the information layers. For example, when moving from a certain sector of one information layer to a certain sector of another information layer, a dense seek is executed only once.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a configuration example of an optical disc device to which the recording medium recording / reproducing device of the present invention is applied will be described, and further, processing executed by the optical disc device will be described.

FIG. 1 is a block diagram showing an example of the configuration of an optical disc device to which the recording medium recording / reproducing device of the present invention is applied. In this figure, an optical disc 1 having two information layers has a constant angular velocity (in the case of a CAV (Constant Angular Velocity) disc) or a linear velocity (CLV (Constant Linear Velocit) by a spindle motor 2.
y) The disc has been rotated to become). The pickup 3 irradiates the optical disc 1 with a light beam to record or reproduce information. The error signal generation circuit 4 generates and outputs a focus error signal, a tracking error signal, and a seek error signal from the signal supplied from the pickup 3.

The servo circuit 5 supplies the focus error signal and the tracking error signal among the error signals output from the error signal generating circuit 4 to the focus actuator 11 and the tracking actuator 12 of the pickup 3, and the objective lens 13 Is controlled in the focus direction and the tracking direction. Further, the servo circuit 5 supplies a seek error signal to the sled servo motor 8 via the selector 7, and causes the pickup 3 to move in the radial direction of the optical disc 1 (direction perpendicular to the track).
It is designed to be moved to.

Further, the servo circuit 5 controls the focusing actuator 11 and the tracking actuator 12 of the pickup 3 in response to a control signal from the system controller 6 so that the irradiation position of the light beam is the target layer. It is designed to be moved to (layer jump) or to be fine seek.

The system controller 6 composed of a microcomputer also controls each part of the system and also controls the sled servo motor 8 when performing a rough seek having a large movement distance. There is.

The selector 7 is controlled by the system controller 6 and selects either the output from the servo circuit 5 or the output from the system controller 6 and supplies it to the sled servo motor 8. In the normal recording or reproducing mode, the selector 7 is connected to the servo circuit 5 side, and the sled servo motor 8 is controlled by the servo circuit 5. Further, in the coarse seek mode, the system controller 6 switches the connection of the selector 7 from the servo circuit 5 to the system controller 6 side and directly controls the sled servo motor 8 to execute a large distance movement.

FIG. 2 is a flow chart for explaining an example of processing executed in the optical disk device shown in FIG. This processing is executed when it is necessary to move the irradiation position of the light beam from the current address to the target address. When the processing is executed, in step S50, the system controller 6 causes the position where the light beam is currently irradiated (addresses of the information layer, the track, and the sector).
Check.

That is, for example, in the reproduction mode, the focus servo, the tracking servo, and the seek servo are turned on, and the pickup 3 irradiates the track of the optical disc 1 with the light beam through the objective lens 13, The information recorded on the track is reproduced from the reflected light. The system controller 6 reads the current address from this reproduction signal.

In the next step S51, the system controller 6 calculates the difference between the current layer and the target layer, and determines whether or not movement between layers is necessary. As a result, when it is determined that the movement between the layers is not necessary (NO), the processes of steps S52 and S53 are skipped, and the process proceeds to step S54. If it is determined that movement between layers is necessary (YES), the process proceeds to step S52.

In step S52, the system controller 6 determines, based on the difference value between the current layer and the target layer,
The servo circuit 5 is controlled to turn off the focus servo, tracking servo, and seek servo. Furthermore, the actuator 1 for focusing the layer jump signal
Output to 1. Then, the focus servo is turned on in a new layer. As a result, the light beam can be moved (focus jump) to the target layer.

Next, in step S53, the system controller 6 confirms the light beam irradiation position (track and sector address) in the new layer (layer after movement), as in step S50. Therefore, the system controller 6 controls the servo circuit 5 to turn on the tracking servo and the seek servo in a new layer.

In the following step S54, the system controller 6 determines whether or not the current position (address) and the target position (address) are equal to each other (YES).
If it is determined that the processing is completed, the processing is ended (seek end). If it is determined that the current position and the target position are not equal (NO), the process proceeds to step S55.

In step S55, the system controller 6 determines whether the value obtained by subtracting the current position from the target position is larger than the threshold value. As a result, when it is determined that the value obtained by subtracting the current position from the target position is larger than the threshold value (YES), the system controller 6 controls the servo circuit 5 to turn off the tracking servo and the mixing servo while proceeding to step S56. A coarse seek control signal is output to the sled servo motor 8 via the selector 7 to move the pickup 3 (coarse seek).

It should be noted that the seek requires a radial distance between two points or the number of tracks, but in the present embodiment, the system controller 6 sets the sector address for each layer and the radial distance (internal Since it has a correspondence table with the number of tracks from the circumference), it is possible to perform seek between different layers.

In addition to this, the address of a certain sector in a certain layer may be converted into the address of a sector in another layer at substantially the same position in the radial direction by a certain formula or the like.

If the system controller 6 determines in step S55 that the value obtained by subtracting the current position from the target position is smaller than the threshold value or they are equal to each other (NO), the process proceeds to step S57, and the system controller 6 proceeds. Reference numeral 6 controls the servo circuit 5 to supply a fine seek control signal to the tracking actuator 12 to move the objective lens 13 of the pickup 3 to perform a fine seek. That is, the operation of jumping one track at a time is repeated to jump a predetermined number of tracks. Then, it returns to step S53 and repeats the same processing.

According to the above processing, it is possible to omit the dense seek in the layer currently irradiated with the light beam (the layer before the movement) at the time of seek accompanied by the interlayer movement.
The seek speed can be improved by the time required for a dense seek.

In the above embodiment, rough seek is performed after the interlayer movement. However, the interlayer movement may be performed after performing the rough seek in the current layer.

FIG. 3 is a flow chart for explaining an example of processing for realizing such a seek. When this process is executed, in step S70, the system controller 6 confirms the position (address of the information layer, track, and sector) where the light beam is currently emitted. That is, for example, if it is now in the reproduction mode, the focus servo, tracking servo, and seek servo are turned on, and the pickup 3 irradiates the track of the optical disc 1 with a light beam through the objective lens 13 and the reflected light thereof. To play the information recorded on the track. The system controller 6 reads the address from this reproduction signal.

Then, in step S71, the system controller 6 determines whether or not the value obtained by subtracting the current position (address) from the target position (address) is larger than the threshold value. As a result, when it is determined that the value obtained by subtracting the current position from the target position is larger than the threshold value (YES), the process proceeds to step S72, where the system controller 6 transfers the sled servo motor 8 to the coarse servo motor 8 via the servo circuit 5 and the selector 7. A seek control signal is output, the irradiation position of the light beam is moved by a value obtained by subtracting the current position from the target position, and rough seek is executed. As a result, the irradiation position of the light beam moves to the track of the current layer that corresponds to the target track of the target layer (the position on the optical disc 1 corresponds).

In the following step S73, the system controller 6 determines whether or not movement between layers is necessary. As a result, if it is determined that movement between layers is necessary (YES), the process proceeds to step S75, and if it is determined that it is not necessary (NO), the process of step S75 is skipped and the process proceeds to step S76.

On the other hand, in step S71, the system controller 6 determines that the value obtained by subtracting the current position from the target position is smaller than the threshold value or they are equal (NO).
If so, the process proceeds to step S74.

In step S74, the system controller 6 determines whether or not movement between layers is necessary. As a result, when it is determined that the movement between the layers is not necessary (NO), the processes of steps S75 and S76 are skipped, and the process proceeds to step S77. If it is determined that movement between layers is necessary (YES), the process proceeds to step S75.

In step S75, the system controller 6 controls the servo circuit 5 to output a layer jump signal to the focus actuator 11. Then, the focus servo is turned on in a new layer. As a result, the irradiation position of the light beam can be moved to the target layer (focus jump).

In a succeeding step S76, the system controller 6 confirms the current position of the light beam on the moved layer, and in a step S77, determines whether or not the current position and the target position are equal. For this purpose, the system controller 6 controls the servo circuit 5 to turn on the tracking servo and the seek servo in a new layer.

In step S77, when the system controller 6 determines that the current position and the target position are equal (YES), the process ends (seek end). If it is determined that the current position and the target position are different (NO), the process proceeds to step S78.

In step S78, the system controller 6 determines whether the value obtained by subtracting the current position from the target position is larger than the threshold value. As a result, when it is determined that the value obtained by subtracting the current position from the target position is larger than the threshold value (YES), the process proceeds to step S79 and the servo circuit 5
Also, the sled servomotor 8 is controlled via the selector 7 to perform rough seek. Then, the process returns to step S76 and the same processing is repeated.

In step S78, the system controller 6 determines that the value obtained by subtracting the current position from the target position is smaller than the threshold value or they are equal (N
If it is determined to be O), the process proceeds to step S80. Then, the system controller 6 controls the servo circuit 5 and drives the tracking actuator 12 to perform a dense seek. Then, the process returns to step S76 and the same processing is repeated.

Since the error caused in the movement between layers (step S75) is usually within a range that can be absorbed by a dense seek, after the movement between layers, in step S78, the value obtained by subtracting the current position from the target position is a threshold value. Smaller than or equal to (NO), a fine seek (step S80) is executed. Then, in the second loop, the current position and the target position are equal (step S7
It is determined to be YES in 7), and the processing ends. Therefore, in a normal case, the dense seek is executed once after the movement between layers, and the processing is ended.

According to the above processing, since it is possible to omit the dense seek in the layer currently irradiated with the light beam (the layer before the movement), it is possible to improve the seek speed accordingly.

In the above embodiment, after the movement between the layers (step S52 and step S75), the current position on the new layer is confirmed (step S53 and step S53).
Then, it is determined whether or not the current position has reached the target position (step S54 and step S54).
77). However, since the coarse seek originally contains a considerable error, the distance moved by the coarse seek is
Even if it is obtained from the address of the current position and the address of the target position before the interlayer movement, there is practically no inconvenience. That is, since the error generated during the movement between layers is generally smaller than the error generated during the rough seek, even if the seek movement distance includes the error due to the interlayer movement, no substantial difference occurs. Therefore, the confirmation of the address immediately after the inter-layer movement can be omitted.

FIG. 4 is a flow chart for explaining an example of processing for realizing such a seek. When this processing is executed, the system controller 6 executes step S9.
0, the same processing as that described above (step S50
Alternatively, the current position is confirmed by the processing of step S70). Then, the system controller 6 determines whether the value obtained by subtracting the current position from the target position is larger than the threshold value (step S91). As a result, when it is determined that the value obtained by subtracting the current position from the target position is larger than the threshold value (YES), the process proceeds to step S92.

In step S92, the system controller 6 determines whether interlayer movement is necessary. As a result, when it is determined that the movement between the layers is necessary (YES), the process proceeds to step S93, the movement between the layers is performed, and the process proceeds to step S94. If it is determined that movement between layers is not necessary, the process of step S93 is skipped,
It proceeds to step S94.

In step S94, the system controller 6 sends a coarse seek control signal to the sled servo motor 8 via the selector 7 to execute a coarse seek. Then, the process proceeds to step S97.

On the other hand, in step S91, when the system controller 6 determines that the value obtained by subtracting the current position from the target position is smaller than the threshold value or they are equal (NO), the process proceeds to step S95, and the interlayer Determine if a move is necessary. As a result, if it is determined that the movement between the layers is necessary (YES), the process proceeds to step S96, the movement between the layers is executed by the same processing as step S93, and the process proceeds to step S97. If it is determined that there is no need to move between layers (NO), the process of step S97 is skipped and the process proceeds to step S98.

In step S97, the current position is confirmed by the same processing as in step S90.
Then, the process proceeds to step S98, and it is determined whether or not the current position and the target position are equal. As a result, if it is determined that the current position and the target position are equal (YES), the process ends (seek end). If it is determined that the current position and the target position are not equal, the process proceeds to step S99.

In step S99, the system controller 6 determines whether the value obtained by subtracting the current position from the target position is larger than the threshold value. As a result, when it is determined that the value obtained by subtracting the current position from the target position is larger than the threshold value (YES), the process proceeds to step S1010, after performing the rough seek, the process returns to step S97 and the same processing is repeated.
If it is determined that the value obtained by subtracting the current position from the target position is smaller than the threshold value or if they are equal (NO), the process proceeds to step S100, the dense seek is executed, and then the process returns to step S97 and the same is performed. Repeat the process.

In the above embodiment, since the confirmation of the address immediately after the inter-layer movement is omitted, the tracking servo and the seek servo are turned on, and the PLL (Phase Locked Loop) for generating the clock necessary for confirming the position is omitted. ) It is possible to omit the servo pull-in (correction of the deviation of the reference signal caused by the interlayer movement). Also, the optical disc 1
In the case of the CLV disk, since the CLV servo pull-in (correction of the deviation of the rotation speed of the spindle motor 2 caused by the interlayer movement) can be omitted, the seek speed can be further improved.

In the above embodiments, the recording medium is an optical disc, but the present invention can be applied to the case of recording or reproducing information on a recording medium other than the optical disc. Further, the number of information layers may be any number as long as it is 2 or more.

[0064]

According to the recording medium recording / reproducing apparatus of the first aspect and the recording medium recording / reproducing method of the seventh aspect, a plurality of coarse seeks and fine seeks are combined to make a plurality of addresses from the current address to the target address. When performing a seek including a movement between information layers, the target address is confirmed after the movement between the information layers, so that the seek time can be shortened.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a configuration of an optical disc device to which a recording medium recording / reproducing device of the present invention is applied.

FIG. 2 is a flowchart illustrating an example of processing executed in the optical disc device of FIG.

FIG. 3 is a flowchart illustrating another example of processing executed in the optical disc device of FIG.

FIG. 4 is a flowchart illustrating still another example of processing executed in the optical disc device of FIG.

FIG. 5 is a flowchart illustrating a conventional seek process.

FIG. 6 is a flowchart illustrating a conventional seek process including movement between information layers.

[Explanation of symbols]

1 optical disk, 2 spindle motor, 3 pickup, 4 error signal generation circuit, 5 servo circuit, 6 system controller, 7 selector,
8-thread servo motor

Claims (7)

[Claims] 1. A recording medium having a plurality of information layers,
In a recording medium recording / reproducing apparatus for recording or reproducing information by a light beam, when performing seek including movement between the plurality of information layers from a current address to a target address by combining coarse seek and fine seek, The recording medium recording / reproducing apparatus, wherein the confirmation of the address is performed after the movement between the information layers. 2. The method according to claim 1, wherein, when the seek including the movement between the plurality of information layers is performed, the movement between the information layers is performed first, and then the rough seek or the dense seek is performed. Recording medium recording / reproducing apparatus. 3. The moving distance of the light beam when performing the rough seek is set to the current address of the current information layer,
The recording medium recording / reproducing apparatus according to claim 2, wherein the calculation is performed from a target address of a target information layer. 4. When the rough seek is performed after the movement between the information layers, the irradiation position of the light beam is after the movement between the information layers and before the rough seek. 3. The recording medium recording / reproducing apparatus according to claim 2, wherein the confirmation of the address is not performed. 5. The seek of the light beam including the movement between the plurality of information layers, the rough seek is performed first, and then the movement between the information layers is performed. Recording medium recording / reproducing apparatus. 6. The address of the irradiation position of the light beam is not confirmed after the rough seek but before the movement between the information layers. Recording medium recording / reproducing apparatus. 7. A recording medium having a plurality of information layers,
In a recording medium recording / reproducing method of recording or reproducing information by a light beam, when a seek including a movement between a plurality of information layers from a current address to a target address is performed by combining coarse seek and fine seek, The recording medium recording / reproducing method, wherein the confirmation of the address is performed after the movement between the information layers.