JPH04209330A - Optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent runaway of a head by restarting seeking, reading and writing after standing by until drifting of a mobile part of a lens becomes the level not generating the head runaway. CONSTITUTION:The commands of seek, read, write, etc., from a host computer 22 are received by a control part 24, and the driving part 23 is controlled to carry out seeking, reading, and writing operations. Head runaway error signal from the head runaway detection circuit 25 is fed to the control part 24. When the signal (i) is received by the control part 24, control signal to interrupt reading and/or writing is fed to a drive part 23 and the reading and/or writing is restarted immediately after the specified waiting time, or the control signal (j) is fed to the driving part to restart reading and/or writing after carrying out seeking. This transfer wait is set to be the period of time the drifting of the mobile part of the lens becomes a level where running away does not occur after the head has ran away.

Description

[Detailed description of the invention]

[00011

[Industrial Application Field] The present invention uses an optical head to
The present invention relates to an optical information recording and reproducing apparatus that records information on a recording medium or reproduces information that has already been recorded, and particularly relates to an optical information recording and reproducing apparatus that can reduce the probability that an optical head will run out of control. [0002] [Prior Art] In recent years, instead of using a magnetic head, it has become possible to optically write information and read recorded information by focusing laser light and irradiating it onto a recording medium. Optical information recording and reproducing devices that can perform this function have been put into practical use. [0003] This optical information recording/reproducing apparatus generally performs tracking control in order to move a light spot of a laser beam to a predetermined track on a recording medium, for example, a card using light. Means for performing this tracking control include fine movement adjustment means and coarse movement adjustment means. In the fine adjustment means, the tracking actuator is driven to
By slightly moving the objective lens, the light spot of the laser beam is moved to the center of a predetermined track on the optical disk. In addition, the coarse movement adjustment means drives voice coil motors (hereinafter referred to as V, C, and M) to move the optical head composed of the objective lens, tracking actuator, etc., and directs the light spot to a predetermined track. It is designed to perform a seek operation to move it. [0004] By the way, the range of displacement of the light spot by the fine adjustment means is minute, and if the coarse adjustment means is controlled independently, even if the position of the light spot is controlled by the fine adjustment means, it will not be possible to reach a predetermined position. In some cases, it may not be possible to direct the light spot to the target. Furthermore, if the positioning of the objective lens is not reflected in the positioning of the optical head, the track jump of the light spot may be unstable or the light spot may not be able to reach the target track. [0005] In order to solve these problems, the displacement caused by the tracking actuator is detected using a flag,
The detection signal is input to the V, C, M control circuit and V is adjusted so that the displacement of the tracking actuator becomes small. There is a device that controls C and M. This type of control is called two-stage servo. In devices using two-stage servos, if there are defects such as dust or scratches on the card,
A detection signal with a higher level than usual is generated from the flag,
The lens movable section including the objective lens swings significantly via the tracking actuator. As a result, V, C,
The M control circuit sends control signals to V, C, and M so that the lens movable part comes to the neutral position. Then, V, C, M
becomes an excitation source, and the lens movable part shakes even more, causing V
,C. It causes M to go out of control. Therefore, in a device using a two-stage servo, when this runaway occurs, the two-stage servo is temporarily canceled by a head runaway control means. [00061 FIG. 6 is a block diagram showing such a conventional optical information recording/reproducing apparatus. [0007] In this figure, reference numeral 1 denotes an optical head, and this optical head 1 has a lens movable part 3 disposed on V, C, and M2 in a state that it can be shifted in the tracking direction of arrow 91. It has a structure. The reflected light from the light spot 41 on the card 4 enters the detector 6 via the objective lens 5 within the lens movable section 3. Thereby, the detector 6 detects a track position error signal indicating the relative position (shift) of the optical spot 2 with respect to the tracking guide groove provided on the surface of the recording medium of the card 4, and converts this track position error signal into a track position error signal. It is applied to the servo circuit 7. The output terminal of the track servo circuit 7 is connected to a tracking actuator 9 via an amplifier 8, and the track servo circuit 7 is connected to a tracking actuator 9 through an amplifier 8.
In the mode in which the actuator follows the tracking guide groove, the tracking actuator 9
is driven in the tracking direction of arrow 91, and positioning control of the lens movable portion 3 including the objective lens 5 is performed so that the track position error signal becomes 0°, thereby positioning the light spot 41 in the tracking guide groove. At this time, the position of the lens movable part 3 including the objective lens 5 in the tracking direction with respect to V, C, M2 in the optical head 1 is V, C, M.
Detected by a flag 10 fixed to 2. The flag 10 applies the detection result to the terminal a of the switching circuit 11 as a lens position signal. [0008] On the other hand, a linear scale 12 is provided for V, C, and M2, and the positions of V, C, and M2 are detected by this linear scale 12. The linear scale 12 supplies the detection result to the controller 13 as a linear scale signal, and also to the terminal of the switching circuit 11. The output from the common terminal C of the switching circuit 11 is given to the V, C, M control circuit 14. In addition, the controller 13 counts the pulses of the linear scale signal and monitors the amount of movement of the optical head 1 using the value, and if it exceeds a predetermined range (movement range in normal control state), a "head runaway" is detected. I judge that. Alternatively, the speed is detected by differentiating the amount of movement with respect to time, and if this speed exceeds the speed that occurs in normal operation by a certain amount or more, it is determined that the head is running out of control. The switching circuit 11 is given a switching signal from the controller 13, and the controller 13
If the controller 13 does not determine that the head is out of control, terminal a is selected, and if the controller 13 determines that the head is out of control, terminal A is selected. [0009] The V, C, M control circuit 14 is controlled by the controller 13, and when the switching circuit 11 selects terminal a, that is, when the controller 13 does not determine that "head runaway" occurs, V, C, M control circuit 14 is controlled by controller 13. Drive C and M2 to perform two-stage servo. In this two-stage servo, the position where the lens position signal, which is the output of the flag 10, becomes 0 is set as the center position of the spring for supporting the lens movable part 3, so that the tracking guide groove can be adjusted to prevent curvature of the card 4. Even if the lens movable part 3 including the objective lens 5 moves due to the large displacement, the optical head 1 follows the movement of the lens movable part 3, and the lens movable part 3 is always located at the center position of the support spring. Therefore, position offset due to spring force can be prevented. [00101 On the other hand, when the switching circuit 11 selects the terminal, that is, when the controller 13 determines that "head runaway" occurs, the V, C, M control circuit 14 outputs the output according to the scale pitch from the linear scale 12. After binarizing the linear scale signal, the V, C, M control circuit 1
Input it to the counter in 4. This counter is reset to 011 by a reset signal output when the controller 12 determines that the head is out of control.
The C, M control circuit 14 controls the V, C, and M controls so that the count value of this counter is always "0", that is, to return the optical head 1 to the position at which it was determined that the "head runaway" occurred.
It controls M2. [0011] According to such a device, when there is a defect such as dust or scratches on the card during reading and/or writing, the controller 13 determines that the head is out of control and stops the card 4 from adjusting in the track direction. Stop reading and/or writing by the optical head while continuing to move at high speed, and perform V. The C, M control circuit 14 performs control to return the head to the position at which it was determined that the "head runaway" occurred. After this, the controller 13 no longer determines that the head is running out of control, and if the light spot 41 is not off the track, it immediately resumes reading and/or writing, and if the light spot 41 is off the track, it performs seek. read and/or write again. [0012]

[Problems to be Solved by the Invention] In conventional optical information recording and reproducing devices, after the controller determines that the head is running out of control and interrupts reading and/or writing, the controller no longer determines that the head is running out of control. At the time of performing a seek or restarting a read and/or write, the lens movable part may still be at a high level of wobbling due to the head running out of control.
Furthermore, even defects such as dirt or scratches that would not cause runaway in a light can cause the head to run out of control again, increasing the probability that the optical head will run out of control. [001,31 The present invention has been made in view of these circumstances, and the present invention has been made in view of the above circumstances. Wait until the fluctuation of the lens movable part at the time of restarting writing is at a level that will not cause head runaway, and then immediately resume reading and/or writing or seek. An object of the present invention is to provide an optical information recording/reproducing device that can resume reading and/or writing after performing the following steps. [0014]

[Means for Solving the Problems] The optical information recording/reproducing apparatus according to the present invention as set forth in claim 1 temporarily interrupts reading and/or writing of the optical head by means of head runaway control means to prevent wobbling of the lens movable part. Wait until the head is at a level that does not cause runaway, and immediately resume reading and/or writing, or perform seek before reading and/or
or have configured the lights to resume. [0015]

[Operation] In the present invention, seek is performed and read and/or write is restarted after waiting until the fluctuation of the lens movable part reaches a level that does not cause head runaway. and/or to reduce the wobbling of the lens movable part to a level that does not cause the head to run out of control when the light is restarted. [0016]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. [00171 FIGS. 1 and 2 show a first embodiment of an optical information recording/reproducing apparatus according to the present invention, FIG. 1 is a flowchart showing the operation of the apparatus, and FIG. 2 is a configuration diagram. [00181 In FIG. 2, 21 is an optical information recording/reproducing device, and this optical information recording/reproducing device 21 is operated by commands such as seek, read, and/or write from the host computer 22. The optical information recording/reproducing device 21 includes the optical head 1. shown in FIG. card 4
A drive section 23 consisting of mechanical parts such as a support section, and the drive section 23 shown in FIG.
Track servo circuit shown in 7. A control management section 24 that includes electronic components such as a controller 13 and controls the drive section 23; and a head runaway detection circuit that is provided in the controller 13 shown in FIG. 6 and that detects head runaway of the drive section 23. It consists of 25. The control management unit 24 performs seek from the host computer 22. It receives commands such as read and/or write, and controls the drive section 23 to perform seek, read, and/or write operations. Head runaway detection circuit 25
A head runaway error signal i (a reset signal for the controller 13 in the conventional example) is supplied to the control management section 24. When the control management unit 24 receives the head runaway error signal, it supplies the drive unit 23 with a control signal to interrupt reading and/or writing, and immediately starts reading and/or writing after a predetermined waiting time (transfer wait). A control signal j is supplied to the drive unit 23 to restart the read and/or write after resuming the search or seeking. In addition, as a means for providing the above-mentioned transfer weight,
Software means such as a timer in the control management section 24 are used. This transfer weight is set to the time from when the head runs out of control until the wobbling of the lens movable section 3 shown in FIG. 6 reaches a level that does not cause the head to run out of control. [0019] The optical information recording/reproducing apparatus 21 having the above configuration performs operations of interrupting and resuming reading and/or writing in the steps shown in FIG.

[0O20] The control management section 24 is the host computer 22
When a read and/or write command is received, in step S1, the control management unit 24 determines whether the optical head is stopped due to head runaway or not. If the optical head has not stopped due to head runaway, the read and/or write operation in step S3 is performed as usual (seek if the light spot 41 in FIG. 6 is not deviated from the track), but the head If the head is stopped due to runaway, by setting a transfer weight in software in step S2, the head is brought from the state where the lens movable part is wandering due to runaway to a level that does not cause head runaway. After returning, step S3
The read and/or write operation is immediately resumed or the read and/or write operation is performed after seeking. [00211] In this way, in the above embodiment, when the optical head is stopped due to runaway, the lens movable part is prevented by providing a wait time for the execution of seek and/or read and/or write commands using software. Read and/or write is resumed immediately after the wobbling reaches a level that does not cause head runaway, or seek is performed and then read and/or write is resumed, so seek or read and/or write is resumed. This prevents the head from running out of control. FIG. 3 is a block diagram showing a second embodiment of the optical information recording/reproducing apparatus according to the present invention. [00221 In FIG. 3, the host computer 22,
The drive section 23 is similar to the embodiment shown in FIG. The difference in this embodiment is that instead of using software means as a means of setting transfer weights,
This is because hardware means using the delay circuit 35 is used. That is, in the optical information recording/reproducing device 31, by supplying a control signal for performing seek, read, and/or write from the control management section 34 to the drive section 23 via the delay circuit 35, the optical information recording/reproducing device 31 can prevent the head from running out of control. A waiting time is provided until the wobbling of the lens movable section 3 reaches a level that does not cause head runaway. [0023] According to such a configuration, it is possible to prevent the head runaway caused by the wobbling of the head movable part as in the embodiment of FIG. 1, and since it is only necessary to provide the delay circuit 35, it is possible to prevent The design is shown in Figure 1.
This is easier than the example above. [0024] FIG. 4 is a configuration diagram showing a third embodiment of the optical information recording/reproducing apparatus according to the present invention. In Figure 4,
The same components as in FIG. 6 are given the same reference numerals. [0025] Optical head 1, V, C, M2, movable part 3
, card 4, objective lens 5, detector 6, track servo circuit 7, amplifier 8, tracking actuator 9
, flag 10, switching circuit 11, linear scale 12,
The V, C, M control circuit 14 is the same as the conventional example shown in FIG. [00261 In this embodiment, the flag output comparison circuit 100 compares and determines the output signal m of the detection result of the flag 10, and the amplitude is set to a predetermined threshold (the maximum value of the output signal m at which the optical head 1 does not cause head runaway). ) or less, and the detection result is given to the controller 113 as an output signal n. In addition, this controller 11
3 is given a linear scale signal which is the detection result of the linear scale 12. The controller 113 selects the terminal a of the switching circuit 11 when it determines that "head runaway" occurs in response to the linear scale signal. In addition, the controller 113 responds to the linear scale signal by
If it is not determined that "head runaway" has occurred, and the flag output comparison circuit 100 determines that the output is equal to or greater than the threshold value, the switching circuit 11 does not perform terminal switching and continues the current terminal connection. Further, the controller 113 selects the terminal of the switching circuit 11 when the flag output comparison circuit 100 determines that the output voltage is less than or equal to the threshold value. [0027] The operation of such an embodiment will be explained with reference to the waveform diagram of FIG. 5(a) shows the output signal m of the flag 10, and FIG. 5(b) shows the output signal n of the flag output comparison circuit 100. [0028] To explain the operation of this embodiment, when there is a defect such as dust or scratches on the card 4 during reading and/or writing, the controller 113 controls the linear scale 12.
It is determined that the head is running out of control based on the linear scale signal from the controller, selects the terminal of the switching circuit 11, continues to move the card 4 at a constant speed in the track direction, and then stops reading and/or writing by the optical head. The V, C, M control circuit 14 controls the internally provided counter so that the count value is always "0'°," that is, returns the optical head 1 to the position at which it was determined that the "head runaway" occurred. multiply. After this, the flag output comparison circuit 100
As shown in FIG. 5(a), when the output signal m of the flag 10 is compared and determined to be below a predetermined threshold value, as shown in FIG. 5(b), the output signal n of the flag output comparison circuit 100 is low. The controller 113 rises from the level "L" to the high level "HIT", causes the switching circuit 11 to select the terminal a, and immediately resumes reading and/or writing, or resumes reading and/or writing after performing a seek. [0029] According to such an embodiment, seek is performed and read and/or write is restarted after the fluctuation of the lens movable portion 3 reaches a level that does not cause head runaway. lead and/or
Alternatively, it is possible to prevent head runaway when writing is restarted, and the threshold value of the flag output comparison circuit 100 is set to the maximum value of the output signal m at which the optical head 1 does not cause head runaway. Compared to the embodiment described above, wasted time until restarting reading and/or writing can be reduced. [00301Although in the embodiments shown in FIGS. 15, 3, and 4, an optical card is used as the recording medium, it may also be applied to an optical disk as the recording medium. Well, even magneto-optical type discs. It may also be applied to things that use cards. [00311] [Effects of the Invention] As described above, according to the present invention, after the controller determines that "head runaway" has occurred and interrupts the read and/or write, the timing of the read and/or write is Wait until the fluctuation of the lens movable part at the time of restarting is at a level that will not cause head runaway, and then immediately resume read and/or write or seek. reading and/or writing can be resumed.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing a first embodiment of an optical information recording/reproducing apparatus according to the present invention.

FIG. 2 is a configuration diagram of the optical information recording/reproducing apparatus shown in FIG. 1;

FIG. 3 is a configuration diagram of an optical information recording/reproducing apparatus showing a second embodiment of the present invention.

FIG. 4 is a configuration diagram of an optical information recording/reproducing apparatus showing a third embodiment of the present invention.

FIG. 5 is a waveform diagram illustrating the operation of the embodiment in FIG. 4;

FIG. 6 is a configuration diagram showing a conventional optical information recording/reproducing device.

[Explanation of symbols]

21 Optical information recording and reproducing device 23 Drive part 24 Control management department 25 Head runaway detection circuit

[Figure 1]

Claims (1)

[Claims] 1. An optical head having a movable range in the tracking direction of an optical information recording medium, a lens movable part that fixes an objective lens and is driven by a tracking actuator inside the optical head, and this lens movable part. head position control means for detecting the position of and driving the optical head to follow the movement of the lens movable section;
head runaway detection means for detecting head runaway of the optical head caused by the head position control means; An optical information recording/reproducing apparatus comprising: a head runaway control means that interrupts and immediately resumes reading and/or writing, or resumes reading and/or writing after performing a seek, wherein the head runaway control means When the optical head detects head runaway, it temporarily suspends reading and/or writing of the optical head, waits until the fluctuation of the lens movable part is at a level that does not cause head runaway, and immediately starts reading and/or writing. Alternatively, an optical information recording/reproducing device characterized in that reading and/or writing is restarted after restarting writing or after performing seek.