JPH07201048A - Optical information recording / reproducing device - Google Patents

Abstract

(57) [Summary] [Object] To provide an optical information recording / reproducing apparatus capable of detecting tracking deviation with high accuracy without being affected by defects or the like on an optical recording medium. [Structure] When information is recorded on the tracking guide of the optical disc 1 by a light beam, a reflected light beam from the optical disc 1 is detected by a detector 13 having two detection areas. The difference between the detection signals from the two detection areas is generated in the tracking servo circuit 29 as a tracking signal.
This tracking signal is compared with two reference levels of positive and negative after the noise component is removed by the off-track detection circuit 30, and it is confirmed whether the comparison values are continuous. When the comparison signals are continuously output, an off-track signal is generated from the off-track detection circuit 30, the supply of the recording signal signal is blocked, and the information recording on the optical disc by the light beam is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording / reproducing apparatus for recording information on an optical recording medium, and in particular,
The present invention relates to an optical information recording / reproducing apparatus equipped with a tracking circuit for detecting a track deviation of a light beam on an optical information recording medium on which information is already recorded on a tracking guide.

[0002]

2. Description of the Related Art A conventional optical recording / reproducing apparatus, for example, an optical recording medium such as a write-once or an erasable optical disc is used for optically recording information to or from the optical recording medium. In an optical information recording / reproducing apparatus such as an optical disk apparatus for reproducing, a tracking guide is usually formed on an information recording medium, that is, an optical disk, and information is recorded on the tracking guide. This tracking guide is formed in a spiral or concentrically protruding strip-shaped region, in a groove-shaped region, or as a pit row.

Normally, while the tracking guide is being detected, the light beam focused on the tracking guide is irradiated to reproduce information, and by the light beam on which the information is focused while detecting the tracking. It is recorded on the recording layer of the tracking guide. Generally, when the condensed light beam crosses the tracking guide, the reflected light beam has its light intensity level changed because the light beam is diffracted by the tracking guide. Utilizing this, the signal from the detector that detects the reflected light beam is processed to generate the tracking signal. That is, 2
The light beam is guided to a detector having one detection area, and a difference between detection signals from the two detection areas is generated as a tracking signal. This tracking signal shows that when the light beam is tracking the tracking guide,
It is maintained at zero level and is changed to minus or plus level as the light beam deviates in either direction across the tracking guide. Therefore, when the light beam crosses the tracking guide, the tracking signal becomes a positive level or a negative level as a part of the light beam is irradiated to the tracking guide from the zero level where the light beam is completely deviated from the tracking guide. It will be changed to the level. The tracking signal is changed from the positive level or the negative level to the zero level as the light beam crosses the tracking guide, reaches the negative level or the positive level, and the light beam is again deviated from the tracking guide. It will reach zero level.

In the conventional optical information recording / reproducing apparatus, a tracking servo for tracking a tracking guide with a light beam is executed by using this tracking signal, and it is detected that the light beam has deviated from the tracking guide to detect the information. A control for stopping recording or reproduction is executed. In particular, with respect to the tracking error, since the tracking signal has the characteristics of rising and falling, the tracking signal is simply binarized and the occurrence of the binarized signal is detected as the tracking error.

[0005]

However, in the conventional apparatus, the tracking signal fluctuates depending on the defect area generated at the time of manufacturing on the optical disk, that is, the information recording medium, or the scratch area generated later, and the tracking signal changes. It has been pointed out that the tracking signal changes even when the track is being tracked, and the tracking error is detected. Moreover, it has been pointed out that the recording operation is prohibited when such mistracking is detected.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical information recording / reproducing apparatus capable of detecting tracking error with high accuracy without being affected by defects on the optical recording medium. .

According to the present invention, the recording signal generating means for generating the signal to be recorded and the recording light beam modulated in response to the recording signal are generated, and the recording light beam is provided with the optical guide having the tracking guide. Means for directing the reflected light beam from the optical recording medium to a tracking signal, and the tracking signal is compared with predetermined first and second levels, and a level component equal to or higher than a predetermined level Comparing means for generating the first and second comparison signals corresponding to, and comparing the second and second comparison signals with each other to detect a unique signal component generated when the signal deviates from the tracking guide to generate an off-tracking signal. An optical information recording / reproducing apparatus is provided, which comprises: a detecting unit.

Further, according to the present invention, recording signal generating means for generating a signal to be recorded and a recording light beam modulated in response to the recording signal are generated, and the recording light beam is used as a tracking guide. Optical means for directing to the optical recording medium, a means for converting a reflected light beam from the optical recording medium into a tracking signal, and comparing the tracking signal with predetermined first and second levels, and comparing them with a predetermined level or more. Comparing means for generating the first and second comparison signals corresponding to the level component and the first and second comparison signals are compared to detect a unique signal component generated when the recording guide deviates from the tracking guide, and a recording prohibition signal is generated. There is provided an optical information recording / reproducing apparatus, comprising: a detecting unit that generates the signal; and a prohibiting unit that prohibits the supply of the recording signal to the optical unit in response to the recording prohibiting signal. That.

Further, according to the present invention, a recording signal generating means for generating a signal to be recorded and a recording light beam modulated in response to the recording signal are generated, and the recording light beam is used as a tracking guide. Optical means directed to the optical recording medium, a detecting means for detecting a reflected light beam from the optical recording medium in two detection areas, and a tracking signal generating means for outputting a difference between the two detection signals as a tracking signal. And comparing the tracking signal with predetermined first and second levels and comparing the second and second comparison signals with a comparison means for generating first and second comparison signals corresponding to level components equal to or higher than the predetermined level. Then, a detection means for detecting a peculiar signal component generated when it deviates from the tracking guide to generate an out-of-tracking signal and a reference signal by adding two detection signals. In comparison, a double writing detection signal generating means for generating a double writing detection signal and a prohibiting means for prohibiting the supply of the recording signal to the optical means in response to the tracking error signal and the double writing detection signal are provided. An optical information recording / reproducing apparatus is provided.

[0010]

When traversing the tracking guide, a substantially S-shaped or inverted S-shaped positive and negative waveform continuously appears in the tracking signal. Therefore, the tracking signal is compared with the first and second reference levels, and if the comparison values are continuously generated, the device determines that the tracking guide has been crossed, and the off-track signal is generated.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a schematic structure of an optical disk device as an optical information recording / reproducing device according to an embodiment of the present invention. In FIG. 1, an optical recording medium, that is, an optical disk 1, is a doughnut-shaped metal coating layer such as tellurium or bismuth on the surface of a substrate molded in a circle, for example, glass or plastics. -Formed and formed. The optical disc 1 is rotated by a spindle motor 2. The spindle motor 2 is controlled by a control device 26 that operates in response to a control command from the optical disk controller 3 to start, stop, or rotate the rotation. The optical disk controller 3 is composed of, for example, a microcomputer, and the spindle motor 2
It controls the rotation control and so on.

An optical head 4 is arranged below the optical disc 1. By the optical head 4, a light beam is focused on the optical disc 1 to optically record information on the optical disc 1, or information is optically reproduced from the optical disc 1. The optical head 4 includes a semiconductor laser 5,
Collimator lens 6, polarizing beam splitter 7, objective lens 8, and beam splitter 1 for splitting a light beam into two systems.
4, a well-known astigmatic optical system 11 including a cylindrical lens 9 and a convex lens 10, a photodetector 12 for focus detection having a detection area divided into four, and a convex lens 1.
5, and a photodetector 13 for tracking detection having at least two detection regions and the like.

The optical head 4 is arranged so as to be movable in the radial direction of the optical disk 1 by a linear actuator 16 composed of, for example, a linear motor.
The linear actuator 16 is driven by a linear motor servo circuit 20 that generates a drive signal according to an instruction from the optical disc controller 3. That is, the optical head 4 is moved by the linear actuator 16 so as to trace a target track for recording / recording or reproduction with a light beam. The linear actuator 16 includes a position detector 16 for detecting the position of the optical head 4 moved by the linear actuator 16.
A is provided, and the position signal from the position detector 16A is fed back to the linear motor servo circuit 20.

The semiconductor laser 5 includes a laser servo circuit 17
A divergent laser beam is generated by being energized by a drive signal generated from the. When the information is recorded on the recording layer of the optical disc 1, the drive signal is modulated corresponding to the recording signal supplied from the optical disc controller 3 through the interface circuit 24 and the AND gate 32. Depending on the semiconductor laser 5
Generates a strong laser beam whose light intensity is modulated. Further, when the semiconductor laser 5 reads information from the recording layer of the optical disc 1 and reproduces it, a weak laser beam having a constant light intensity is generated from the semiconductor laser 5. The polarization beam splitter 7, which will be described later, includes a photodetector 7A.
Is provided, and a part of the laser beam generated by the semiconductor laser 5 is partially reflected by the polarization beam splitter 7,
This is detected by the detector 7A. The detection signal from the detector 7A is fed back to the laser servo circuit 17, the semiconductor laser 5 is controlled based on this signal, and a stable laser beam is generated from the semiconductor laser 5.

The divergent laser light beam generated from the semiconductor laser 5 is converted into a parallel light beam by the collimator lens 6 and guided to the polarization beam splitter 7.
The laser beam guided to the polarization beam splitter 7 is reflected by the polarization beam splitter 7 and the objective lens 8
And is focused by the objective lens 8 toward the recording layer of the optical disc 1.

The objective lens 8 is moved by the lens actuator 18 as a lens driving mechanism in the optical axis direction, that is,
It is movably supported in a direction orthogonal to the focus direction and substantially the optical axis, that is, in the tracking direction. Then,
The objective lens 8 is kept in focus by being moved in the optical axis direction by the servo signal S2 from the focus servo circuit 19. While the objective lens 8 is kept in focus, the laser beam from the objective lens 8 is focused on the surface of the recording layer of the optical disc 1, and the minimum beam spot of the optical disc 1 is It is formed on the surface of the recording layer.

The objective lens 8 is a lens actuator.
The lens 18 is movably supported in a direction perpendicular to the optical axis, and the objective lens 8 is moved in a direction orthogonal to the optical axis by a tracking servo signal from the tracking servo circuit 19. , Is maintained in the combined track state. In this combined track state, the objective lens 8
The light beam focused on the surface of the recording layer of the optical disc 1 traces the recording track formed on the surface of the recording layer of the optical disc 1. The objective lens 8 is maintained in the in-focus state and the in-track state so that information can be written in and read from the optical disc 1.

The position of the objective lens 8 is detected by the lens position detector 8A, and the detection signal is supplied to the lens position sensor servo circuit 21. With this detection signal, the lens position sensor servo circuit 21 can control the lens actuator 18 to position the lens at a predetermined position, for example, the home position.

The divergent laser light reflected from the recording layer of the optical disk 1 is converted into a parallel beam by the objective lens 8 at the time of focusing, and is returned to the polarization beam splitter 7 again. Then, the light passes through the polarization beam splitter 7 and is split into two laser beams by the beam splitter 14. One of the separated laser beams is guided to a photodetector 12 having a detection region divided into four by an astigmatism optical system 11 composed of a cylindrical lens 9 and a convex lens 10, and depending on a defocus state. The shape of the light beam spot formed on the detector 12 is changed by the light beam. The focus servo circuit 19 processes the two sets of signals output from the two photodetection areas diagonally arranged of the detector 12 to generate a focus signal, and the lens actuator according to the focus signal. 18 is actuated to keep the objective lens 8 in focus.

The other laser beam reflected by the polarization beam splitter 7 and separated by the beam splitter 14 is
It is focused by the convex lens 15 and detected by the detector 13. The detector 13 has two detection areas, and the tracking servo signal is obtained by the tracking servo circuit 29 by taking the difference between the detection signals from the detection areas.
As described above, the lens actuator 18 is differentiated according to this tracking signal, and the objective lens 8 is maintained in the combined track state.

The detection signals from the two detection areas of the detector 13 are added and amplified by the video signal amplification circuit 22 to be converted into a reproduction signal, which is supplied to the optical disk controller 3 through the interface circuit 24. This playback signal is
The information is processed by the optical disk controller 3 and displayed as information on a display device (not shown). The reproduction signal is supplied from the video signal amplifier circuit 22 to the binarization circuit 34,
The binarized signal is supplied to the optical disc controller 3 through the interface circuit 24, converted into code information, and used for detecting double writing and the like.

In the circuit shown in FIG. 1, a control device 26 including a CPU, a ROM, a RAM and an I / O for controlling each part of the circuit based on a control command from the optical disk controller 3 and its control. A D / A converter 28 for D / A converting the control signal from the device 26 is provided. Control commands from the optical disk controller 3 are given to the main controller 26, and these various control commands are decoded to give necessary control signals to each circuit.

In the information recording / reproducing apparatus of the present invention,
Further, a tracking servo signal is supplied, and a detection circuit 30 for detecting an off-track is provided. When the detector 30 detects an off-track, a low-level off-track signal is generated from the detector 30. This off-track signal is supplied to the AND gate 32, where
The ND gate 32 will be closed. Therefore, from the optical disk controller 3 to the interface circuit 24 and A
The recording signal supplied via the ND gate 32 is no longer supplied to the laser servo circuit 17, and the laser servo circuit 1
From 7, the drive signal corresponding to the recording signal is not generated.

The track off detection circuit 30 is specifically constructed as shown in FIG. That is, the eccentric frequency component as a low frequency component generated by the eccentric rotation of the optical disc 1 and the groove noise frequency component as a high frequency component generated based on the non-uniformity of the tracking guide are used as the tracking signal S1.
A bandpass filter 42 for removing from the frequency is connected to the tracking servo circuit 29. The band pass filter 42 extracts only the frequency component generated during the track jump from the tracking signal S1,
The track jump signal S2 is the bandpass filter 4
It is output from 2. The bandpass filter 42 includes an inverting input terminal of the comparator 43A and a comparator 43B.
Connected to the non-inverting input of. This comparator 4
The non-inverting input terminal of 3A is supplied with a threshold signal Ref1 having a certain positive side threshold level (+ Th1), and the inverting input terminal of the comparator 43B has a negative side threshold level (-Th2). The signal Ref2 is supplied. Therefore, when the track jump signal S2 becomes larger than the positive threshold level (+ Th1), the high level comparison signal S3 is output from the comparator 43A.
Further, when the track jump signal S2 becomes smaller than the negative threshold level (−Th2), in other words, when the absolute value of the track jump signal S2 becomes larger than the absolute value of the threshold level (−Th2), the high level comparison signal S4 is output from this comparator 43A. The comparator 43A and the comparator 43B
The output side of is connected to flip-flops 44A and 44B which become active when the comparison signals S3 and S4 become high level. The output side of the flip-flops 44A and 44B is the output S5 of the flip-flops 44A and 44B.
It is connected to an AND gate 45 which outputs the coincidence of S5. The AND gate 45 is connected to the input S of a flip-flop 46 that latches the output of the AND gate 45. The flip-flop 46 is used in the control device 2
When the recording mode signal is not input from 6, it is reset. Further, when the output of the AND gate 45 becomes high level, the flip-flop 46 outputs the high level output from its output terminal Q to the AND gate 32. Therefore, while the output of this flip-flop 46 is at a high level,
The recording signal is supplied to the laser servo circuit 17 via the AND gate 32.

Next, in the optical recording / reproducing apparatus configured as described above, the operation for suppressing the recording of information when the track is off will be described with reference to FIGS.
This will be described with reference to the timing chart shown in FIGS. 5A to 5G.

First, prior to the recording operation, an initial operation for checking the level of the emission beam of the semiconductor laser 5 is started. Then, the lens position sensor servo circuit 21 is operated by a signal from the control device 26, and a pull-in signal for forcibly moving the objective lens 8 from the lens position sensor servo circuit 21 to the lens actuator 18 is given to the lens actuator 18. Is supplied to. As a result, the objective lens 8 is forcibly moved to the home position detected by the lens position detector 8A, and the objective lens 8 is maintained in the defocused state. In this defocused state, power is supplied to the laser servo circuit 17 to energize the semiconductor laser 5, and a reproducing and monitor laser beam is output from the semiconductor laser 5. As a result, the semiconductor laser
The monitor light beam generated from the beam 5 is converted into a current corresponding to the light beam by the photodetector 7A and output as a light beam monitor signal. The monitor signal is compared with the reference level by the laser servo circuit 17, and a drive signal is generated according to the difference. Therefore, the light beam of the semiconductor laser 5 is kept constant.

Next, when a forward signal of the objective lens 8 is generated from the control device 26, the lens position sensor servo circuit 21 drives the actuator 18 to move the objective lens 8 in the focusing position direction. When the objective lens 8 is moved to the vicinity of the in-focus position, the focus servo loop including the focus servo circuit 19 and the lens actuator 18 based on the detection signal detected by the detector 12 is operated. After the completion of the initial operation, the automatic focus control by the focus servo is executed and the objective lens 8 is maintained in the in-focus state. While the objective lens 8 is kept in focus, information is read from the optical disc 1, or normal operation such as writing information on the optical disc is started.

In such a state, the optical disc controller 3 starts outputting a pulsed recording signal. When a high-level recording mode signal is supplied to the detection circuit 30 via the interface circuit 24, the detection circuit 3
The high level signal is supplied from 0 to the AND gate 32, and the recording signal is also supplied to the AND gate 32 via the interface circuit 24. Therefore, the recording signal is supplied to the laser servo circuit 17 via the AND gate 32. In this laser servo circuit 17,
A drive signal corresponding to the recording signal is generated and given to the semiconductor laser 5. As a result, the semiconductor laser 5
An intermittent high-intensity laser light beam is emitted according to the recording signal. The laser light beam is converted into a parallel light beam by the collimator lens 6 and guided to the polarization beam splitter 7. The laser light guided to the polarization beam splitter 7 is reflected by the polarization beam splitter 7 and is incident on the objective lens 8, which is focused by the objective lens 8 toward the recording layer of the optical disc 1. . As a result, a recording portion, for example, a pit is formed on the recording layer to record information.

The divergent laser light beam reflected from the recording layer of the optical disc 1 is converted into a parallel light beam by the objective lens 8 which is kept in focus, and is returned to the polarization beam splitter 7 again. . Then, the light passes through the polarization beam splitter 7 and is split into two light beams by the beam splitter 14. One of the reflected light beams is imaged on the photodetector 12 by the astigmatism optical system 11 including the cylindrical lens 9 and the convex lens 10. The detection signal from the detector 12 is supplied to the focus servo circuit 19 as already described.

The other light beam transmitted through the beam splitter 14 is projected onto the detector 13 by the convex lens 15.
The detection signal from the detector 13 is added by the video signal amplification circuit 22 and supplied to the optical disk controller 3 via the interface circuit 24, and is also binarized by the binarization circuit 34 to be similarly subjected to the interface circuit 24.
Is supplied to the optical disk controller 3 via. The difference between the detection signal from the detector 13 is obtained as a tracking signal by the tracking servo circuit 29,
Off-track detection circuit 30 and lens actuator 1
8 are supplied.

While the laser beam is normally tracking the tracking guide by the action of the tracking servo circuit 20 and the lens actuator 18, the output of the detection circuit 30 is at a high level, indicating that no track deviation has occurred. Signal is AND gate 32
And the recording signal is continuously supplied to the laser servo circuit 17. However, as shown in FIG. 3, the laser beam Ls1 tracking the certain tracking guide Tr1 causes a track jump to an adjacent tracking guide, particularly an already recorded adjacent tracking guide Tr2 due to some cause, and the tracking guide Tr2 is moved. When tracking is started as indicated by the reference symbol Ls2, the off-track detection circuit 30 supplies a low-level off-track signal to the AND gate 32 because the off-track has occurred, the AND gate 32 is closed, and the recording signal is emitted from the laser. It is no longer supplied to the servo circuit 17.

Generally, when the light beam crosses the tracking guides Tr1 and Tr2, that is, at the time of a track jump, the tracking servo signal is displaced to the plus side as shown in FIG.
It is positive or negative with an S-shape or an inverted S-shape with two level fluctuations such that it is displaced to the zero level again or to the negative side, then is zero-crossed and then displaced to the positive side, again to the zero level. The waveform of will appear continuously. The track deviation detection circuit 30 detects the track deviation by detecting these two positive and negative level fluctuations. Therefore, it is possible to prevent the tracking servo signal from fluctuating due to a defective area such as a scratch on the optical recording medium, that is, the optical disc 1 and being erroneously detected as an off-track.

FIG. 5A shows the tracking servo circuit 2
9 shows the waveform of the tracking signal S1 supplied from 9 to the detector 30. The tracking signal S1 contains an eccentricity frequency component and a groove noise frequency component, but these components are removed by the bandpass filter 42, and the track jump signal components J1, J2, J3 as shown in FIG. , J4 and defective components D1 and D2 generated by the defective area on the optical disc 1 are supplied to the comparators 43A and 43B. The track jump signal components J1, J2, J3, J4 and the defect components D1, D2 have threshold levels Th1, Th2.
Since its absolute value is larger than that of the comparator 43A,
A binary signal as shown in FIGS. 5C and 5D is generated from 43B. 5 (c) and FIG.
The binarized signal shown in (d) is the flip-flop 44.
When input to A and 44B, its output is as shown in FIG.
As shown in (f), the pulse width will be extended. Therefore, the track jump signal components J1, J2,
Regarding J3 and J4, there will always be overlapping timings,
In addition, the components D1 and D2 of the defect signal hardly overlap in timing. Therefore, from the AND gate 45 to which the signals shown in FIGS.
As shown in (g), the component J1 of the track jump signal,
High level signals corresponding to J2, J3 and J4 are generated. When this high-level signal is input to the input S of the flip-flop 46, the flip-flop 46 is set to switch its output Q, and the low-level signal is supplied to the AND gate 32 as an off-track signal. Therefore, the recording signal is not supplied to the laser servo circuit 17.

In the optical recording / reproducing apparatus shown in FIGS. 1 and 2, it is possible to reliably detect the off-track without being affected by defects on the optical disk 1, and to reliably detect the information when the off-track occurs. Can be suppressed from being recorded on the optical disc 1.

Next, another embodiment of the optical recording / reproducing apparatus having the track deviation detecting circuit 30 will be described with reference to FIG. In the circuit of FIG. 6, the same parts as those of FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. In the circuit of FIG. 6, the off-track detection circuit 30 includes the NAND gate 50.
One input of the NAND gate 50 and the other input of the NAND gate 50 are connected to the double writing detection circuit 52. Therefore, a low-level off-track signal is generated from the off-track detection circuit 30, and the light beam is used to re-record in the area of the tracking guide in which information has already been recorded.
When a low level double write signal is output from the double write detection circuit 52 that detects double writing, a high level write inhibit signal is output from the NAND gate 50, and this signal is output via the interface circuit 24 to the optical disk controller. 3 and the supply of the recording signal is stopped.

The double writing detection circuit 52, when a recording light beam is applied to an already recorded area where information has already been recorded,
Utilizing the fact that the reflected light level from the recorded area is lower than the light intensity level reflected from the unrecorded area, the detection signals from the detector 13 are added and compared with the reference value.
It can be composed of a digitization circuit. Also, instead of immediately determining that the amount of reflected light from the optical disc 1 is small, it is determined that the writing is double writing. You may. An example of the former double writing is Japanese Patent Application No. 60-1009.
76, and the latter example is disclosed in Japanese Patent Application No. 1-110.
105 and 1-110106 (corresponding US Pat. No. 5,161,
144).

[0037]

As described in detail above, according to the present invention,
By detecting the signal component peculiar to the off-track, it is possible to be sure without being affected by the defect on the optical recording medium.
Moreover, it is possible to provide an optical information recording / reproducing apparatus capable of detecting the tracking deviation with high accuracy.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an optical information recording / reproducing apparatus according to an embodiment of the present invention.

2 is a block diagram showing an off-track detection circuit shown in FIG. 1. FIG.

FIG. 3 is a plan view for explaining an off-track state in which a light beam deviates from a tracking guide on an information recording medium.

FIG. 4 is a waveform diagram showing a tracking signal output from the tracking servo circuit shown in FIG.

5 is a waveform chart showing signals supplied to respective parts of the circuit shown in FIG.

FIG. 6 is a block diagram showing a schematic configuration of an optical information recording / reproducing apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 1 ... Optical disc 2 ... Spindle motor 3 ... Optical disc controller 4 ... Optical head 5 ... Semiconductor laser 12, 13 ... Photodetector 16 ... Linear actuator 26 ... Control device 30 ... Track off detection circuit 32 ... AND gate 42 ... Bandpass filter 43A , 43B ... Comparator

Claims (5)

[Claims] 1. A recording signal generating means for generating a signal to be recorded, and a recording optical beam modulated in response to the recording signal,
Optical means for directing the recording light beam to an optical recording medium having a tracking guide, means for converting a reflected light beam from the optical recording medium into a tracking signal, and the tracking signal having predetermined first and second levels. And a comparison means for generating first and second comparison signals corresponding to level components equal to or higher than a predetermined level, and a unique signal component generated when the second and second comparison signals are compared to deviate from the tracking guide. An optical information recording / reproducing apparatus, comprising: a detecting unit that detects a signal and generates an out-of-tracking signal. 2. A recording signal generating means for generating a signal to be recorded, and a recording optical beam modulated in response to the recording signal,
Optical means for directing the recording light beam to an optical recording medium having a tracking guide, means for converting a reflected light beam from the optical recording medium into a tracking signal, and the tracking signal having predetermined first and second levels. And comparing means for generating first and second comparison signals corresponding to level components equal to or higher than a predetermined level, and a unique signal component generated when the first and second comparison signals are compared to deviate from the tracking guide. An optical information recording / reproducing apparatus, comprising: a detection unit that detects a recording prohibition signal to generate a recording prohibition signal; and a prohibition unit that prohibits the supply of the recording signal to the optical unit in response to the recording prohibition signal. . 3. A recording signal generating means for generating a signal to be recorded, and a recording optical beam modulated in response to the recording signal,
Optical means for directing the recording light beam to an optical recording medium having a tracking guide, detecting means for detecting a reflected light beam from the optical recording medium in two detection areas, and tracking a difference between the two detection signals Tracking signal generating means for outputting as a signal, comparing means for comparing the tracking signal with predetermined first and second levels, and generating first and second comparison signals corresponding to level components of a predetermined level or higher, 2 and the second comparison signal are compared to detect a unique signal component generated when the signal is out of the tracking guide to generate an out-of-tracking signal; and two detection signals are added and compared with a reference signal. Double writing detection signal generating means for generating a double writing detection signal, and an optical recording signal in response to the off tracking signal and the double writing detection signal. The optical information recording and reproducing apparatus characterized by comprising a prohibiting means for prohibiting the supply of the stage, the. 4. The detecting means includes means for extending the pulse widths of the first and second comparison signals, and means for comparing the first and second comparison signals having the extended pulse widths. 2. The optical information recording / reproducing device according to any one of 2 and 3. 5. The optical information recording / reproducing apparatus according to claim 1, wherein the comparing means includes a filter means for removing noise from the tracking signal.