JPH0253227A - Optical information recording and reproducing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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 movable in the radial direction of the optical disk over 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.

[Prior Art] In general, in optical disk storage, information is recorded on a concentric or circular information recording track formed on an optical disk, or on a track at an arbitrary position. In order to read information, a desired track position is searched by a slider with an external scale that is movable within a predetermined movable range in the radial direction of the optical disc, and a recording/playback head mounted on the slider is positioned at this search position. Access control is in place.

For example, as described in Japanese Patent Application Laid-Open No. 61-68781, the access control operation of a conventional head is performed by using a slider that can move within a predetermined movable range in the radial direction of the disk and using a near motor or the like; This is performed by controlling the movement of both the recording/reproducing head mounted on the top and capable of relative movement in the radial direction, and can be roughly divided into coarse search, which roughly approximates the target track position by moving a slider using the external scale, and After the hunting of the slider at the target track position due to this coarse search has subsided, the head is moved based on the detection of track information to find and position the target track.This is a two-step control. .

The slider has the property of sensitively responding to external vibrations during its movement. For this reason, during high-speed movement for coarse search during random access, the slider may collide with a fixed part of the device due to the influence of external vibrations, which can lead to a serious situation. This could damage the head (pickup), which is the core of this type of recording/reproducing device and is mounted on the slider. For example, a comb damper is provided near the innermost circumference and near the outermost circumference, and the damper absorbs the shock at the time of a collision.Furthermore, a limit switch detects a collision of the slider and cuts off the slider drive current, thereby controlling the operation of the device. was stopped.

[Problems to be Solved by the Invention] According to the conventional system, there are the following problems in the operation for returning the optical disk device to normal operation after the slider has collided.

Firstly, if the slider collides, the device will stop, so the series of startup operations must be repeated from the beginning each time. There is a drawback that it takes time to start the rotation of the disk at the time of startup.

Secondly, considering the case where a slider collision occurs during a series of data access operations, it would take time to restart the access operation from the beginning after restarting the device. If the state is to be returned to the state before the slider collision after the collision, a function is required to store the state of the device at the time of an accident and reproduce this stored state after restarting. In this case, the information to remember is:
The amount of accessed data, its addresses, etc. is enormous. Should this feature be addressed in hardware or software? It will be complicated and large-scale, and there will be an unavoidable disadvantage in terms of cost.

The present invention has been made in order to improve such problems, and even if a slider collides, the device does not stop and the access operation is restarted with as little wasted time as possible while the disk is rotating, thereby eliminating the slider collision. An object of the present invention is to provide an optical information recording/reproducing device that can suppress the loss of access time due to the occurrence of the error.

[Means for Solving the Problems] In the present invention, a reading or recording head is mounted on a 6L slider movable in the radial direction of an optical disk over a predetermined movable range, and the above-mentioned head is moved by moving the slider. In an optical information recording and reproducing device that performs an access operation to a target track position within a movable range, a collision detection means detects that the slider reaches its movement limit position during the access operation; a retracting means for forcibly moving the slider to a predetermined retracting position within the movable range, preferably a substantially central position of the movable range based on a detection output of the detecting means; The above-mentioned problem is achieved by including a recovery means for restarting the operation from the retreated position.

[Function] In the optical information recording/reproducing apparatus of the present invention, when the slider collides with a damper or the like during a rough search, the collision detection means generates a detection signal, and the evacuation means temporarily stops the slider by a control operation by a microprocessor or the like. The disk is forcibly evacuated to a preset evacuation position within the movable range in the radial direction of the disk.

During this time, the disk continues to rotate t11, 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 forcible movement is performed, the address of the evacuation position can be moved from the evacuation position to the target track position by a control operation by the recovery means or a microprocessor or the like. Resumes slider access operation.

In this way, in the present invention, there is no need to stop the device even after a slider collision, so it does not take time to stop and restart the device.

In addition, if the slider retraction position is set at approximately the center of the disk's radial movable range, the time it takes for the slider to move to the retraction position will be longer than the disk's This is approximately half the time it takes to move from the first track position to the last track position. 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 the time the slider collides 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 access 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 the flow of its operation.

In FIG. 1, a slider 2 mounted with an optical information recording/reproducing head 2a faces one side of an optical disc 1 rotated by a drive device (not shown) and is movable relative to the disc 1 in the radial direction. The slider 2 is provided with an external scale 5 for position reading such as an encoder. The movable range of the slider 2 is set corresponding to the positions of the innermost track and the outermost track of the disk 1 by a pair of dampers 3a and 3b on the inner and outer circumferential sides, which are spaced apart in the disk radial direction. has been done. Each damper has a limit switch 4a.
, 4b are attached, and when the slider 2 collides with each damper, the corresponding limit switch generates a collision detection signal.

The movement control system for the slider 2 is mainly composed of a control unit (CPU) 6 including a microprocessor. The position reading signal of the slider 2 by the scale 5 is A/D.
The data is digitized by a converter 9 and provided to the CPU 6. Collision detection signals from the limit switches 4a and 4b are also provided to the CPU 6, respectively. CPU6
includes a random access memory (for temporarily storing target track position information for track search by slider 2).
RAM) 10 and one-only memory (ROM) 11 for storing preset disc center track position information.
and the data human power device 12 are connected, and the slider drive control unit 8 is connected from the CPU 6 via the D/A converter 7.
A slider speed voltage command is given to

Now, when the device is started, disk 1 rotates at a constant speed, and C
PU6 starts a coarse search operation. In this case, the CPU 6 controls the slider 2 via the D/A converter 7 based on the target track position information provided from the input device 12 and the current position information of the slider 2 provided from the scale 5 via the A/D converter 9. A speed voltage command is sent to the drive control unit 8 to move the slider 2 to the target track position.

In this way, the access operation for moving the slider 2 to the target position is performed, but if the slider 5 collides with the damper 38 or 3b during this rough search, the CPU 6
performs a series of re-access controls according to the operational flow shown in FIG.

For example, if the slider 2 collides with the inner damper 38 during the coarse search access operation, the corresponding limit switch 4a is turned ON, and this collision detection signal is transmitted to the CPL 16.
The CPU 6 executes the program with the following operational flow shown in FIG.

That is, when the CPUA receives the collision detection signal, it stores the target track position information at that time in the RAM10. Also,
The CPU 6 reads the disk center track position information from the ROM II, and while sequentially reading the current position information from the scale 5 via the A/D converter 9, drives the slider via the D/A converter 7 so as to eliminate the difference between the two. A slider speed voltage is applied to the control section 8, and the slider 2 is retracted to the disk center track position determined by the 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 unit 8 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. .

[Effects of the Invention] As described above, according to the present invention, even if the slider collides with the damper, the disk device can continue its operation, so the wasted time that was conventionally required can be significantly reduced. This method has the advantage that a large increase in cost can be avoided because the device configuration can be realized using a simple microprocessor and memory.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a main part of an embodiment of the present invention, and FIG. 2 is a flowchart showing a main part of control in the embodiment of FIG. [Explanation of symbols of main parts] 1...Disc, 2...Slider, 3a, 3b...
・Damper, 4a, 4b river limit switch, 5...
External scale, 6... Control unit (CPU), 7.
...D/A converter, 8...Slider drive control section,
9...A/D converter, RAM for 10, 11・R
OM12...Input device.

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. In an optical information recording and reproducing device that performs an access operation to a position, a collision detection means detects that the slider reaches its movement limit position during the access operation, and a detection output of the collision detection means is provided. a retracting means for forcibly moving the slider to a predetermined retracted position within the movable range based on the movement of the slider, and a recovery means for restarting the access operation from the retracted position after the forcible movement by the retracting means. Optical information recording and reproducing device with special features. 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.