JPH09102163A - Optical disk drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hardly disturb a control system by foreign matters, scratches and stains on an optical disk and to perform highly reliable recording and reproduction by comparing the change of reflected light quantity from a recording carrier by two comparison levels and controlling a light spot position. SOLUTION: A digital signal processing circuit 4 is provided with comparator circuits 9 and 10 for comparing the reflected light quantity from the optical disk 1 respectively by a first comparison level and a second comparison level and a holding circuit 11 for controlling an actuator when the reflected light quantity is abnormal. Then, a switching circuit 12 switches output to the actuator from a control arithmetic circuit 14 to the holding circuit 11 by the output of the comparator circuit 9. Further, upon detecting that the reflected light quantity becomes larger than the second comparison level after becoming smaller than the second comparison level by the output of the comparator circuit 10, the switching circuit 12 switches the holding circuit 11 to the control arithmetic circuit 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc device characterized by an optical pickup movement control of a device for recording or reproducing a signal on a record carrier surface using a converged light spot.

[0002]

2. Description of the Related Art Conventionally, Japanese Patent Application Laid-Open No. 60-107749 discloses a technique relating to a device for detecting scratches, foreign matters, and dirt on an optical disk and preventing disturbance of focus and tracking control.
Is described in Japanese Patent Application Publication No.

An optical disk device has an information track of 1.6 μm pitch provided on a record carrier of an optical disk and has a size of about 1 μm.
The optical spot of φ is about ± 0.5μ in the direction perpendicular to the surface of the record carrier
Performs highly accurate focus control that follows with m accuracy. Also, the track deviation between the information track and the light spot is about ±
Performs highly accurate tracking control that follows with 0.1 μm accuracy. If such an optical disc has scratches, foreign matter, or dirt, the control is disturbed and the optical disc is jumped to another information track.
There is no control.

Conventionally, a comparison circuit compares the fact that the amount of reflected light decreases due to scratches, foreign matters, and dirt on an optical disk with a predetermined value.
It was detecting scratches and foreign objects.

[0005]

However, in the conventional configuration, the comparison value of the comparison circuit is set to be sufficiently smaller than the normal reflected light amount in order to detect scratches, foreign matters, and dirt on the optical disk with high reliability. It is necessary, and in this case, a delay in detection of a scratch or the like occurs, and the control system is disturbed.

On the contrary, in order to prevent the detection delay, the comparison level is set to a value slightly smaller than the normal reflected light amount. However, if this is done, even small scratches and foreign matter on the optical disc that do not affect the control system will be detected, and if they are continuously present, the control system will be disturbed and jump to another information track, or control will be lost. It becomes impossible to record or play.

The present invention solves the above problems, and provides an optical disk apparatus capable of reliably following a recording surface or an information track even if the optical disk is slightly scratched, foreign matter, or dirt, and stabilizing recording and reproduction. The purpose is to

[0008]

In order to achieve the above object, the optical disk device of the present invention comprises first comparing means for comparing the amount of light reflected from the record carrier at a first comparing level,
Second comparing means for comparing the reflected light quantity at the second comparison level, abnormal time control means for controlling the light spot moving means when the reflected light quantity is abnormal, and output to the light spot moving means by the output of the first comparing means. The output is switched from the light spot position control means to the abnormal condition control means, and after the reflected light amount becomes smaller than the second comparison level, it is detected from the output of the second comparison means that it becomes larger than the second comparison level. A control signal switching means for switching the abnormal time control means to the light spot position control means.

Further, a light quantity abnormal time measuring means for measuring the time from the detection of the first comparing means to the decrease of the reflected light quantity from the second comparing level by the second comparing means and the light quantity abnormal time measuring means. When the time becomes longer than the predetermined time, a control signal switching means for switching the abnormal time control means to the light spot position control means is provided.

When the abnormal time control means is operated and the abnormal time control means and the light spot position control means are switched, the output of the light spot position control means is not switched to the output of the abnormal time control means for a predetermined time. A control signal switching means is provided.

Further, when the storage means for storing the output data of the light spot position control means for a predetermined time and the abnormal time control means operate, the storage means is stored in a direction opposite to the moving direction of the light spot moving means for the stored predetermined time. Control signal switching means for outputting data to the light spot moving means.

Further, the storage means is operated by the detection of the first comparison means, and when the reflected light amount decreases from the second comparison level by the second comparison means, it moves in the direction opposite to that stored in the storage means. As described above, the data of the storage means is output to the moving means, the output to the light spot moving means is switched from the light spot position control means to the abnormal time control means, and the reflected light amount becomes larger than the second comparison level. Control signal switching means for detecting the output from the comparing means and switching the abnormal time control means to the light spot position control means.

As a result, it is possible to obtain an optical disk device capable of reliably following the recording surface or the information track even if the optical disk is slightly scratched, foreign matter or dirt, and stabilizing recording and reproduction.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is a light spot irradiation means for irradiating a light spot on a recording surface formed on a record carrier, and the recording surface or the recording surface. A positional deviation detecting means for detecting a deviation from the information track, an optical spot moving means for moving the optical spot in a direction substantially perpendicular to the recording surface or a direction substantially orthogonal to the information track, and a signal of the positional deviation detecting means. Accordingly, the light spot position control means for controlling the light spot moving means, the first comparing means for comparing the reflected light quantity of the light spot from the record carrier at the first comparison level, and the reflected light quantity for the second comparison. Second comparing means for comparing at a comparison level, abnormal time controlling means for controlling the light spot moving means when the amount of reflected light is abnormal, and the light spot moving means by the output of the first comparing means. Output from the light spot position control means to the abnormal condition control means, and after the reflected light quantity becomes smaller than the second comparison level, it becomes larger than the second comparison level. And a control signal switching means for switching the abnormal time control means to the light spot position control means by detecting from the output of the optical disc device. The first comparison means detects a decrease in the amount of reflected light, The output to the light spot moving means is switched from the light spot position control means to the abnormal time control means to detect early and reduce the detection delay of the abnormality processing, and the reflected light quantity becomes smaller than the second comparison level. After that, it is detected from the output of the second comparison means that the level is higher than the second comparison level, and the abnormal time control means is controlled by the light spot position control means. By switching the signal switching means has the effect that reduces the influence of the control system due to a scratch or foreign matter of the optical disc, to ensure tracking of the information track of the optical spot optical disk.

According to a second aspect of the present invention, the deviation between the light spot irradiating means for irradiating the light spot on the recording surface formed on the record carrier and the recording surface or the information track formed on the recording surface is detected. Position deviation detecting means, and light spot moving means for moving the light spot in a direction substantially perpendicular to the recording surface or in a direction substantially orthogonal to the information track,
An optical spot position control means for controlling the optical spot moving means in response to a signal from the positional deviation detection means, and a first comparing means for comparing the amount of light reflected from the record carrier of the optical spot at a first comparison level. Second comparison means for comparing the reflected light quantity at a second comparison level, abnormal time control means for controlling the light spot moving means when the reflected light quantity is abnormal, and the second comparison means from the detection of the first comparison means. A light quantity abnormal time measuring means for measuring the time until the reflected light quantity decreases from the second comparison level by the second comparing means;
When the output to the light spot moving means is switched from the light spot position control means to the abnormal time control means by the output of the comparison means, and the measurement time by the light amount abnormal time measuring means becomes longer than a predetermined time, The optical disc device is provided with a control signal switching means for switching the control means to the light spot position control means, and when the measurement time by the light quantity abnormal time measurement means is longer than a predetermined time, the abnormal time control means is changed to the light spot. By providing the control signal switching means for switching to the position control means, it is possible to prevent the operation by detecting scratches, foreign matters, and dirt which are small and have almost no influence on the control system.

According to a third aspect of the invention, when the input to the light spot moving means is switched from the abnormal time control means to the light spot position control means, the output of the light spot position control means is changed to the abnormal time control means. 3. The optical disk device according to claim 1, further comprising a control signal switching unit that does not switch for a predetermined time to output.
When the abnormal time control means is operated and the abnormal time control means and the light spot position control means are switched over, a predetermined time,
In order not to operate the switching from the first comparing means, the light quantity abnormal time measuring means, or the light spot position control means to the abnormal time control means, the control system is operated for continuous small scratches, foreign matters, and dirt. Reduce the effect of.

According to a fourth aspect of the invention, storage means for storing the output data of the light spot position control means for a predetermined time,
When the abnormal time control means operates, it is provided with a control signal switching means for outputting the data of the storage means to the light spot moving means in a direction opposite to the stored moving direction of the light spot moving means for a predetermined time. The optical disk device according to claim 1, 2 or 3, wherein the output data of the light spot position control means is stored in a storage means for a predetermined time, and before the abnormal time control means operates, The light spot moving means is moved in a direction opposite to the direction in which the light spot moving means is moved, based on the data in the storage means, to reduce the influence of scratches or foreign matter on the control system and ensure follow-up.

According to a fifth aspect of the present invention, the deviation between the light spot irradiating means for irradiating the light spot on the recording surface formed on the record carrier and the recording surface or the information track formed on the recording surface is detected. Position deviation detecting means, and light spot moving means for moving the light spot in a direction substantially perpendicular to the recording surface or in a direction substantially perpendicular to the information track,
A light spot position control means for controlling the light spot moving means according to a signal from the position shift detection means, a storage means for storing output data of the light spot position control means for a predetermined time, and a reflected light amount of the light spot. First comparison means for comparing at a first comparison level, second comparison means for comparing the reflected light quantity at a second comparison level, and abnormal time control for controlling the light spot moving means when the reflected light quantity is abnormal Means and the storage means is operated by the detection of the first comparison means, and when the reflected light amount decreases from the second comparison level by the second comparison means, the direction opposite to that when the storage means stores To output the data of the storage means to the moving means, to switch the output to the light spot moving means from the light spot position control means to the abnormal time control means, The control signal switching means for detecting that the reflected light amount becomes larger than the second comparison level from the output of the second comparison means and switching the abnormal time control means to the light spot position control means. And an optical disk device that operates the storage means upon detection by the first comparison means and causes the storage means to operate when the reflected light amount decreases from the second comparison level by the second comparison means. After outputting the data of the storage means so that the moving means moves in the opposite direction to the time of storing, the output to the light spot moving means is switched from the light spot position control means to the abnormal time control means, When the second comparison means detects that the reflected light amount becomes larger than the second comparison level, the abnormal time control means is switched to the light spot position control means, Or to ensure the effect was less follow-up to the control system by foreign objects.

An optical disk device according to an embodiment of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram of an optical disk device according to Embodiment 1 of the present invention. Hereinafter, the optical disc device according to the first embodiment will be described with reference to FIG.

An optical disk 1 as a record carrier is provided with a motor 2
To rotate. In order to follow the optical spot on the recording surface of the optical disc 1 and the information track, the digital signal processing circuit 4 causes the focus actuator and the tracking actuator (not shown as a part of the optical head 3) of the optical head 3 via the drive circuit 5. Make it work.

The light spot radiated from the optical head 3 as the light spot radiating means is reflected by the optical disc 1,
Returning to the optical head 3, the optical head 3 outputs the reflected light amount to the RF amplifier 6 as a light amount signal. The RF amplifier 6 is
Light intensity signal (only the servo error signal is considered here)
Is amplified and output to the digital signal processing circuit 4.

In the digital signal processing circuit 4, the focus error signal or tracking error signal (hereinafter referred to as servo error signal) from the RF amplifier 6 is converted into an analog-digital conversion circuit (hereinafter referred to as AD conversion circuit) 7
The digital-analog conversion circuit (hereinafter referred to as D
It is converted into an analog signal by the A conversion circuit 8) and is output to the drive circuit 5.

In the drive circuit 5, a focus actuator for making the light spot follow the recording surface, a tracking actuator for making the light spot follow the information track, a traverse mechanism 17 for moving the optical head 3 to the inner or outer circumference of the optical disk 1, and the optical disk. A drive signal is output to each of the motors 2 that rotate the. The focus actuator and the tracking actuator as the light spot moving means are collectively referred to as an actuator hereinafter.

If the optical disc 1 has scratches, foreign matter, or dirt,
As shown in FIG. 2, the light amount signal reflected from the optical disc 1 decreases. This light amount signal corresponds to the comparison level 2 shown in FIG.
If it becomes smaller, the servo error signal will not be detected correctly, and the control system will become unstable, requiring control in the event of an abnormality.

Since the servo error signal does not correctly indicate an error between the light spot and the information track of the optical disk 1, it cannot be used as a drive signal for the actuator.

Therefore, the hold circuit 11 as the abnormal time control means holds and outputs the low frequency component of the signal that has been output up to that point.

By doing so, the actuator does not operate abnormally while passing through a scratch, a foreign substance, or a dirty portion.

However, since the follow-up control is not performed, if the hold value is output for a long time, the positions of the recording surface of the optical disc 1 or the information track and the light spot are displaced.

In the present embodiment, the digital signal processing circuit 4 compares the light amount signal with a predetermined level by the first
The comparison circuit 9 as the comparison means and the comparison circuit 10 as the second comparison means.

As shown in FIG. 3, the light quantity signal and the comparison level 1 which is the first comparison level are compared by the comparison circuit 9, and when the comparison level is smaller than 1, the signal to the drive circuit 5 is sent to the inside of the digital signal processing circuit 4. The switching circuit 12, which is the control signal switching means, switches to the output of the hold circuit 11, which is the abnormal state control means performed in step 1.

Further, as shown in FIG. 3, the time after detecting that the light level becomes smaller than the comparison level 1 is measured by the flaw detection timer circuit 13 which is the light quantity abnormal time measuring means, and the light quantity signal is obtained from the comparison level 2. When becomes smaller than the predetermined time a, the signal to the drive circuit 5 of the digital signal processing circuit 4 is switched from the hold circuit 11 to the control arithmetic circuit 14.

Thus, as shown in FIG. 4, scratches continuously smaller than the comparison level 1 but having little influence on the control system,
Stop outputting unnecessary hold signals for foreign matter and dirt.

Further, even if there are continuous pulse-like scratches, foreign matters, and dirt, the waveform as shown in FIG. 3 can be obtained by passing the light amount signal through the low-pass filter.

Therefore, the light spot can follow the recording surface of the optical disc 1 or the information track.

Further, as shown in FIG. 5, when the digital signal processing circuit 4 detects that the light quantity has become smaller than the second comparison level, ie, the comparison level 2, when the digital signal processing circuit 4 becomes larger than the comparison level 2, the hold circuit 11 To the control arithmetic circuit 14.

In this way, at the comparison level 2, the control arithmetic circuit 1
By switching to 4, the control after passing through scratches, foreign substances, and dirt can be performed more quickly and stably than switching at the comparison level 1.

If the light amount decreases from the comparison level 1 and does not reach the comparison level 2 and the light amount returns before the predetermined period a has elapsed (when it becomes larger than the comparison level 1), the hold circuit The output from 11 is switched to the control arithmetic circuit 14. At this time, after switching to the control arithmetic circuit 14, the detection of the comparison level 1 is stopped for a predetermined period b. Alternatively, the switching circuit 12 does not operate for the predetermined period b.

After switching from the hold circuit 11 to the control arithmetic circuit 14, the hold circuit 1 is operated for a predetermined period b.
Not to switch to 1 may also be performed in the cases shown in FIGS. 4 and 5. For example, in FIG. 4, the amount of light becomes smaller than the comparison level 1 and is switched to the hold circuit 11. Since the comparison level 2 is not reached even after the predetermined period a, the control operation circuit 14 is switched to, and thereafter, for a predetermined period b. Comparison level 1 detection is stopped.

In this way, the output of the hold circuit 11 is kept continuous and the control system is not destabilized when the light amount is continuously reduced a little.

Further, by changing the comparison level 1 and the comparison level 2 in accordance with the radial area, position and information track shape of the optical disk 1, it is possible to accurately deal with scratches, foreign matters and dirt.

In this embodiment, the comparison level is 2
Although it is provided and processed, depending on the type of optical disc,
The same effect can be obtained by changing the setting of the comparison level or further increasing the number of setting of the comparison level and switching the settings.

FIG. 6 shows a flow for detecting and processing a foreign substance or the like on the optical disc 1. In step 1, the light amount signal is compared with the comparison level 1. If it is larger, go to the end (END) process. If it is smaller, go to step 2. Step 2
Then, hold the drive signal. That is, it switches to the hold circuit 11. In step 3, the light amount signal is compared with the comparison level 1. If so, go to step 7. If it is smaller, go to step 4. In step 4, if the light quantity signal is less than or equal to the comparison level 2, go to step 6, and if it is greater than the comparison level 2, go to step 5. Step 5
Then, if a predetermined time has elapsed, go to step 7, and if not, go to step 3.

In step 6, if the light quantity signal is equal to or lower than the comparison level 2, the procedure goes to step 6 again, and if it is higher than the comparison level 2, the procedure goes to step 7. In step 7, the hold of the drive signal is released. After step 7, the process goes to the next process as the END process.

In the flow shown in FIG. 6, EN
If this flow is not started for a predetermined time after the D process, the drive signal is not held (or the light level signal is compared with the comparison level 1) regardless of the magnitude of the light level signal.

(Second Embodiment) FIG. 7 is a block diagram showing a configuration of an optical disk device according to a second embodiment of the present invention. Hereinafter, in FIG. 7, differences from the first embodiment will be mainly described.

As shown in FIG. 7, the output of the control arithmetic circuit 14 is continuously stored for a predetermined time in the memory circuit 15 which is a storage means for storing the output data of the light spot position control means for a predetermined time. The comparison circuit 10 detects that the light amount has decreased, and the memory switching circuit 16 switches it to the output of the memory circuit 15 via the scratch detection timer circuit 13, outputs the stored data, and outputs the DA conversion circuit 8 and the drive circuit 5. The focus actuator or the tracking actuator of the optical head 3 is driven via the
The actuator is moved so as to correct the amount moved due to dirt or the like. When the memory for a predetermined time is output, the scratch detection timer circuit 13 causes the switching circuit 12 to hold the hold circuit 1.
Switch to 1 output.

After passing through scratches, foreign matters, and dirt on the optical disk 1,
When the amount of reflected light increases and exceeds the comparison level 2, the switching circuit 12 and the memory switching circuit 16 are switched, and the output of the control arithmetic circuit 14 is added to the DA conversion circuit 8. The memory switching circuit 16 may be switched when the memory circuit 15 outputs a predetermined time.

In FIG. 8, A indicates the amount of light and B indicates the drive voltage of the actuator. Further, c is a period during which data for moving the actuator in the opposite direction is being output from the memory circuit 15 which stores the output of the control arithmetic circuit 14 immediately before the light amount is reduced below the comparison level 2, and d is the hold circuit. This is the period during which the data from 11 is being output.
C indicates the output period from the memory circuit 15.

During a period of the drive voltage B other than c and d, the output data of the control arithmetic circuit 14 is output as the drive voltage.

Further, as shown in FIG. 9, the comparison level 1 and the comparison level 2 are provided for the reflected light quantity, and the comparison level 1
When it is further decreased, the input to the memory circuit 15 is started, and when it is lower than the comparison level 2, the output from the memory circuit 15 is started. By doing so, the operation period of the memory circuit 15 can be shortened.

When the light amount of the input to the memory circuit 15 is smaller than that of the comparison level 1 and longer than that of the comparison level 2, it may be stopped at a predetermined time.

In each of the embodiments, the comparison level 1 or the comparison level 2 is set to reduce the light amount. However, compared with the normal state, the light amount increases in the abnormal state. The same effect can be obtained even if the comparison levels 1 and 2 are set to increase levels.

Further, as the abnormal time control means, the low frequency component of the error signal is fixed and held. However, the differential coefficient of the low frequency component of the error signal is obtained, and the differential coefficient is calculated until the light quantity returns to normal. You may change to.

The same effect can be obtained even if the digital signal processing section of the internal processing circuit of the digital signal processing circuit 4 is processed by software.

[0056]

As described above, according to the present invention, when the record carrier has scratches, foreign matter, or dirt, the amount of reflected light is
Abnormality control means is quickly executed at a first comparison level that detects an abnormality with a slight decrease, and a passage of scratches, foreign matter, or dirt is reliably detected at a second comparison level that is set smaller than the first comparison level. Then, the abnormal time control means is released and returned to the light spot position control means which is the normal control, so that stable control of the light spot position can be performed.

When the amount of reflected light becomes smaller than the first comparison level, storage of the output data of the light spot position control means is started in the storage means, and when it becomes smaller than the second comparison level, it is stored in the storage means. The output data to the optical spot moving means is added so that the moving direction is the opposite direction, and then the control means is switched to the abnormal condition to stabilize the follow-up control to the information track of the record carrier, and the highly reliable optical disc. The device is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram of an optical disc device according to a first embodiment of the present invention.

FIG. 2 is a conceptual diagram showing changes in a light amount signal.

FIG. 3 is a conceptual diagram showing a change in light amount signal and a comparison level 1.

FIG. 4 is a conceptual diagram showing a change in light amount signal and a comparison level 2.

FIG. 5 is a conceptual diagram showing changes in a light amount signal and a hold period.

FIG. 6 is a schematic flow chart for explaining foreign matter detection.

FIG. 7 is a block diagram of an optical disc device according to a second embodiment of the present invention.

FIG. 8 is a conceptual diagram showing a change in light amount signal and a driving voltage.

FIG. 9 is a conceptual diagram showing changes in a light amount signal and memory circuit operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 optical disk 2 motor 3 optical head 4 digital signal processing circuit 5 drive circuit 6 RF amplifier 7 AD conversion circuit 8 DA conversion circuit 9, 10 comparison circuit 11 hold circuit 12 switching circuit 13 flaw detection timer circuit 14 control arithmetic circuit 17 traverse mechanism

Claims (5)

[Claims] 1. A position deviation detecting means for detecting a deviation between a light spot irradiating means for irradiating a recording surface formed on a record carrier with a light spot, and a deviation between the recording surface or an information track formed on the recording surface, Light spot moving means for moving the light spot in a direction substantially perpendicular to the recording surface or in a direction substantially orthogonal to the information track, and light spot position control for controlling the light spot moving means in response to a signal from the position deviation detecting means. Means, first comparing means for comparing the amount of light reflected from the record carrier of the light spot at a first comparison level, second comparing means for comparing the amount of reflected light at a second comparison level, and the reflection An abnormality control means for controlling the light spot moving means when the light quantity is abnormal, and an output to the light spot moving means from the light spot position control means by the output of the first comparing means. The abnormality control is performed by switching to the abnormality control means, detecting that the reflected light amount has become larger than the second comparison level after it becomes smaller than the second comparison level, from the output of the second comparison means. An optical disk device comprising a control signal switching means for switching the means to a light spot position control means. 2. A position deviation detecting means for detecting a deviation between a light spot irradiating means for irradiating a light spot on a recording surface formed on a record carrier and a recording surface or an information track formed on the recording surface. Light spot moving means for moving the light spot in a direction substantially perpendicular to the recording surface or in a direction substantially orthogonal to the information track, and light spot position control for controlling the light spot moving means in response to a signal from the position deviation detecting means. Means, first comparing means for comparing the amount of light reflected from the record carrier of the light spot at a first comparison level, second comparing means for comparing the amount of reflected light at a second comparison level, and the reflection The abnormal light control means for controlling the light spot moving means when the light quantity is abnormal, and the reflected light quantity reduced from the second comparison level by the second comparison means from the detection of the first comparison means. The light quantity abnormal time measuring means for measuring the time until the light quantity decreases and the output to the light spot moving means by the output of the first comparing means are switched from the light spot position control means to the abnormal time control means, and the light quantity is changed. An optical disk device comprising: a control signal switching means for switching the abnormal time control means to a light spot position control means when the time measured by the abnormal time measuring means is longer than a predetermined time. 3. When the input to the light spot moving means is switched from the abnormal time control means to the light spot position control means,
3. The optical disk device according to claim 1, further comprising a control signal switching unit that does not switch the output of the light spot position control unit to the output of the abnormal time control unit for a predetermined time. 4. Storage means for storing output data of the light spot position control means for a predetermined time, and when the abnormal time control means operates, the storage means is in a direction opposite to the stored movement direction of the light spot moving means for the predetermined time. 4. The optical disk device according to claim 1, further comprising a control signal switching means for outputting the data of 1. to the light spot moving means. 5. A position deviation detecting means for detecting a deviation between a light spot irradiating means for irradiating a recording surface formed on a record carrier with a light spot and a recording surface or an information track formed on the recording surface, Light spot moving means for moving the light spot in a direction substantially perpendicular to the recording surface or in a direction substantially orthogonal to the information track, and light spot position control for controlling the light spot moving means in response to a signal from the position deviation detecting means. Means, storage means for storing output data of the light spot position control means for a predetermined time, first comparing means for comparing the amount of light reflected from the record carrier of the light spot at a first comparison level, and the amount of reflected light Of the first comparison means, a second comparison means for comparing the above-mentioned at a second comparison level, an abnormal time control means for controlling the light spot moving means when the reflected light amount is abnormal, Upon detection, the storage means is operated, and when the second comparison means reduces the reflected light amount from the second comparison level, the data of the storage means is moved so as to move in a direction opposite to that stored in the storage means. Is output to the moving means, and the output to the light spot moving means is switched from the light spot position control means to the abnormal time control means, and the reflected light amount becomes larger than the second comparison level. An optical disk device comprising: a control signal switching means for detecting the output from the comparing means and switching the abnormal time control means to the light spot position control means.