JPH0253228A - Optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent a slider from colliding before it happens and to reduce a loss of access time due to the occurrence of the slider collision by resuming an access operation from a withdrawal position after a forced movement by a withdrawal means. CONSTITUTION:When the slider moving speed is extremely fast, the collision of the slider 2 is detected as an abnormal movement of the slider 2 by an abnormal detecting means, such as a microprocessor. When a detecting signal is generated by the abnormal detecting means, the slider 2 is once forcibly withdrawn into the preset withdrawal position within a movable range in the radial direction of a disk 1 by the withdrawal means. An address for the withdrawal position can previously fixedly be stored in a memory of the device, and after performing the forced movement, the access operation of the slider 2 is resumed from the withdrawal position to a target track position by a recovery means with the control operation of the microprocessor, etc. By this method, the slider 2 is prevented from colliding before it happens, and it is not necessary for the device to stop even after the abnormal movement of the slider is detected, thus taking no time required for stopping and starting the device.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical information recording and reproducing device,
In particular, a reading or recording head is mounted on a slider that is movable in the radial direction of the optical disk within a predetermined movable range, and movement of the slider allows access to a target track position within the movable range. The present invention relates to an optical information recording/reproducing device (hereinafter referred to as an optical disk device) of a type that performs the following.

[Conventional technology]

Generally, in an optical disk device, the concentric or spiral information recording tracks formed on the optical disk are
In order to record information on a track at an arbitrary position or read recorded information, a desired track position is determined by a slider with an external scale that is movable within a predetermined movable range in the radial direction of the optical disc. Access control is performed to search for and position a recording/reproducing head mounted on a slider at this search position.

For example, as described in Japanese Unexamined Patent Publication No. 81-18781, the access control operation of the conventional head is performed using a slider that can move within a predetermined movable range in the radial direction of the disk and uses a near motor or the like. This is performed by controlling the movement of both the recording/reproducing head mounted on the slider and movable in the radial direction, and broadly speaking, it is roughly approximated to the target track position by moving the slider using the external scale. A two-stage control is used: search, and fine search in which the target track is found and positioned by moving the head based on the detection of track information after the hunting of the stepper at the target track position due to the rough search has subsided. It is being done.

After the slider detects the target track, tracking ffjJOii is performed to make the head follow the track during data recording/reproducing operations, and the slider also moves in the disk radial direction as necessary to help control the tracking of the head. Move to. As described above, during the data recording/reproducing operation after the target track has been detected, the slider has the property of sensitively responding to external vibrations during its movement. Therefore, during data recording/reproducing operations, the Bg
9 may cause a serious situation in which the slider hits a fixed part of the device 111. This could result in damage to the head (pink-up), which is the core of this type of recording/reproducing device and is marked +=i on the slider. For example, a comb damper is provided near the innermost circumference and outermost circumference of the disk, and these dampers absorb the impact at the time of a collision, and a limit switch detects a slider collision [cutting off the slider drive current]. and stopped the operation of the device.

[Problems to be Solved by the Invention] According to the conventional method, not only could the problem be dealt with only after the slider collided, but the following operations were required to restore the optical disk device to normal operation after the collision. There was a problem.

Firstly, if the slider collides, the device will stop, so each time a collision occurs, the series of start-up operations must be repeated from the beginning, and the disk rotation stop operation that is performed when the device is stopped, as well as the device's operation. There is a drawback that it takes time to start the rotation of the disk at the time of restart.

Second, slider collisions may occur when recording a large amount of data.
Considering the case where this occurs during playback, it would take time to restart the access operation from the beginning after starting up the device again, and it would be a collision if you wanted to return to the state before the slider collision after starting up the device again. It is necessary to have a function to memorize the state of the device and to reproduce this memorized state after restarting the device. In this case, the information to be stored includes accessed data and its addresses, and the amount of information is enormous. Even if this feature is handled by hardware,
Or even if you deal with it with software? 1.It will be complicated and large-scale, and the disadvantage in terms of cost cannot be avoided.

The present invention was made to improve these problems, and it prevents collisions of the sliders, and also rotates the disk without stopping the device when abnormal movement of the slider that would lead to a collision occurs. It is an object of the present invention to provide an optical information recording/reproducing apparatus which can perform a re-access operation with as little wasted time as possible while the slider remains open, and can reduce the loss of access time due to occurrence of slider collision.

[Means for solving the aI problem] In the present invention, a reading or recording head is mounted on a slider movable in the radial direction of an optical disk over a predetermined movable range, and by movement of the slider, the In an optical information recording and reproducing apparatus that performs an access operation to a target track position within a movable range, the slider's sliding condition, for example, speed, is monitored during data recording/reproducing operation to detect abnormal movement of the slider. Based on the abnormality detection means to detect and the detection output of the abnormality detection means, the slider is set to the above-mentioned! an evacuation means for forcibly moving to a predetermined evacuation position within the Jl range, preferably a substantially central position of the movable range; and a recovery means for restarting the access operation from the evacuation position after the forcible movement by the evacuation means. By preparing for this, we have achieved the above-mentioned tasks.

[Operation] In the optical information recording/reproducing apparatus of the present invention, for example, the moving speed of the slider is monitored by a microprocessor or the like during a data access operation during data recording/reproducing. In other words, regarding the movement of the slider, the speed of the slider 8 during data recording/reproduction during normal access operations is not set, and the slider moves in the disk radial direction to help the head follow the track. For example, if a disk rotates at 1800 rpm and its track pitch is 1.6 μm, a reasonable slider movement speed is about 48 μm/sec.

If the slider movement speed is significantly faster than this,
Depending on the direction, it is determined that the slider is about to collide with the inner or outer damper, and this is detected as abnormal movement of the slider by an abnormality detection means such as a microprocessor. When the abnormality detecting means generates a detection signal, the retracting means forcibly retracts the -H slider to a preset retracted position within its movable range in the disk radial direction by a control operation by a microprocessor or the like. During this time, the disk continues to rotate, and there is no need to stop it.The address of the evacuation position can be fixedly stored in the memory of the device in advance, and after the forced movement, The recovery means restarts the access operation of the slider from the retreat position to the target track position by a control operation by a microprocessor or the like.

As described above, in the present invention, slider collisions are prevented and there is no need to stop the device even after abnormal movement of the slider is detected, so it does not take time to stop and restart the device.

In addition, the slider retraction position can be adjusted especially in the disk radial direction.
When set to approximately the center position of the J range, the time it takes for the slider to move to the retracted position is from the first track position to the last track position, regardless of whether the slider collides with the damper on the inner or outer side of the disk. It takes about half the time. Similarly, the time it takes to move from the retreat position to the target track position is approximately half the time it takes to move from the first track position to the last track position in the longest case.

Therefore, the operation from when the abnormal movement of the slider is detected until the end of the re-access operation is completed within approximately the same time as the time it takes for the slider to move from the first track position to the last track position. Therefore, the time required for re-accessing does not become significantly longer due to slider collision.

Embodiments of the present invention will be described below with reference to the drawings.

[Embodiment] FIG. 1 shows the basic configuration of main parts according to an embodiment of the present invention in the form of a block diagram, and FIG. 2 shows its operation.

In FIG. 1, a slider 2 mounted with an optical axis recording/reproducing head 4 is movable relative to the disk 1 in the radial direction, facing one side of an optical disk l rotated by a drive device (not shown). This slider 2 has the digit g! of the encoder, etc. An external scale 5 for reading is provided. The movable range of the slider 2 is set by a pair of dampers 3a and 3b on the inner and outer circumferential sides arranged with an interval in the disk radial direction, corresponding to the positions of the innermost track and the outermost track of the disk l. has been done.

Move slider 2! The llJ monitoring and control system is mainly composed of a control unit (CPU) 6 made up of a microprocessor. The position read signal of the slider 2 by the scale 5 is digitized by the A/D converter 9 and converted to C.
It is given to PU6.

The CPU 6 includes a timer 14 that generates a scale reading request signal at fixed time intervals, an input device 12 for manually inputting target track position information etc. for track search using the slider 2, and temporarily stores this target track position information and performs the above-mentioned A random access memory (RAM) 10 for storing position information of a position read signal from the scale 5 based on a request signal from a timer 14, and a read only memory (ROM) for storing preset disk center track position information. ) 11 are connected,
Furthermore, a slider speed voltage command is given from the CPU 6 to the slider drive control section 8 via the D/A converter 7, and a control command is also given to the head control section 13 which drives and controls the precision search operation of the helad 4. It has become.

Now, when the device is started, disk l rotates at a constant speed, and C
PU6 starts a coarse search operation. In this case, the cpua controls the slider 2 via the D/A converter 7 based on the target track position information given from the input device 12 and the current position information of the slider 2 given from the scale 5 via the A/D converter 9. A speed voltage command for moving the slider 2 to the target track position is output to the drive control section 8.

In this way, the access operation for moving the slider 2 to the target position is performed, and the timer 14 sends a scale reading request signal to the CPU 6 at fixed time intervals during data recording/reproducing after moving to the target position.

The control operation by the CPU 6 will be explained below with reference to FIG.

That is, during data access, CPU 6 starts timer 1.
When the CPU 6 receives the request signal from the scale 5, the CPU 6 converts the current position reading signal of the scale 5 into the A/D converter 9.
, and store it in FtAMlo. In this case, the CPU 6 uses the RAM l0 when receiving the request signal - times before.
Read out the previous scale reading position information that was stored in If the value becomes smaller than a predetermined tolerance value, an abnormality detection signal is generated. That is, when this abnormality detection signal is generated, the CPU 6 determines that the slider 5 is sliding in the inner circumferential direction or the outer circumferential direction and is about to collide with the damper 38 or 3b. As shown in FIG. 2, if the CPU 6 does not generate an abnormality detection signal, it stores the current scale reading position information taken in at that time in RAMl0, and if it generates an abnormality detection signal, it executes the operation flow shown in FIG. Execute a series of re-access control programs according to the following.

For example, if the slider 2 slips during a coarse search access operation and the abnormality detection signal is generated within the CPUB, the CPU
5 stores the target track position information at that time in RAMl0 in response to the abnormality detection signal. Also, CPU6 is R
The disk center track position information is read from the OM 11, while the current position information is sequentially read from the scale 5 via the A/D converter 9, and the difference between the two is eliminated. A slider speed voltage is applied to section 8, and slider 2 is retracted to the disk center track position determined by external scale 5.

Current position information from scale 5 and ROM 11 on CPU 6
When it is confirmed that the disc center track position information matches the disc center track position information, the CPU 6 retrieves the target track position information stored in the RAM 10 and restarts a rough search to move the slider 2 closer to the target track position determined by the external scale 5. In this case as well, the slider speed voltage is applied to the slider drive control section via the D/A converter 7 while sequentially reading out the external scale 5 via the A/D converter 9 as described above, and the slider 2 is moved to the target track position. It goes without saying that it must be moved.

When the access position and the read position of the scale 5 match in this manner, the CPU 6 sends a track following command to the head control section 13, and the head 4 performs a track following operation.

[Effects of the Invention] As described above, according to the present invention, it is possible to prevent the slider from colliding with the damper, and even if the slider moves abnormally, it is possible to restart the disk device while continuing its operation. Because it can be accessed, it has the effect of greatly reducing the wasted time that was previously required, and because the equipment configuration can be realized with a simple microprocessor and memory, a significant increase in costs can be avoided. There is.

[Explanation of symbols of main parts]

Claims (1)

[Claims] 1. A reading or recording head is mounted on a slider movable in the radial direction of the optical disk over a predetermined movable range, and a target track within the movable range is set by moving the slider. An optical information recording/reproducing device configured to perform an access operation to a position, comprising: an abnormality detection means for detecting abnormal movement of the slider by monitoring a movement state of the slider during movement of the slider for the access operation; an evacuation means for forcibly moving the slider to a predetermined evacuation position within the movable range based on a detection output of the abnormality detection means; and resuming the access operation from the evacuation position after the forcible movement by the evacuation means. 1. An optical information recording/reproducing device comprising: recovery means. 2. The optical information recording/reproducing apparatus according to claim 1, wherein the retracted position is set at a substantially central position of the movable range. 3. The optical information recording/reproducing apparatus according to claim 1, wherein the abnormality detection means monitors the moving speed of the slider.