JPH0622064B2 - Optical recording / reproducing device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording / reproducing apparatus for recording, reproducing and erasing by irradiating a recording medium with a light beam generated from a light source.

2. Description of the Related Art As a record carrier used in the above-described device, a thin film containing tellurium low oxide TeO _x (x is a value smaller than a chemical equivalent value) as a main component is provided on a base material having concave and convex grooves, and is formed on the base material. Some have a protective layer. This recording material has two stable states, an amorphous state and a crystalline state, and the states can be mutually changed by the thermal action of light (JP-A-59-18).
No. 5048).

As a device using this kind of record carrier, two light sources for recording and reproducing and for erasing are provided, and a light beam generated from the light source for recording and reproducing on the record carrier is generated from the light source for erasing in a substantially circular shape. It has been proposed that the light beams are configured to be converged into elliptical shapes that are long in the track direction (Japanese Patent Laid-Open No. 59-172167).

In this proposal, tracking control is performed so that a recording / reproducing light beam scans an uneven groove-shaped track (hereinafter referred to as an information track), and at the time of recording, the light amount of the light beam generated from the recording / reproducing light source is recorded. The signal is recorded by modulating the intensity according to the signal, the light beam generated from the recording / reproducing light source is adjusted to a weak constant amount during reproduction, and the signal is reproduced by receiving the reflected light from the record carrier. , At the time of erasing, the light beam generated from the recording / reproducing light source is set to the light amount at the time of reproducing, the light beam generated from the erasing light source is set to a predetermined light amount, and the material whose state has been changed by recording is returned to the original state. Was being done.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the above-mentioned conventional apparatus, the recording / reproducing light beam and the erasing light beam on the record carrier have a predetermined interval, and at the time of erasing, the recording / reproducing light beam is an information beam. Since the signal was erased by the erasing light beam while performing tracking control so as to scan over the track, the erasing light beam did not accurately scan the information track, and the erasure residue might occur. .

Means for Solving the Problems The present invention is intended to eliminate the above-mentioned conventional drawbacks, and an erasing light beam for detecting a track shift between an erasing light beam on a record carrier and an information track. Track deviation detecting means, scanning moving means for scanning an erasing light beam on the record carrier in a direction perpendicular to the information track direction,
There is provided an erasing beam tracking means for driving the scanning moving means in response to the signal of the erasing light beam track deviation detecting means and tracking so that the erasing beam on the record carrier always scans the information track. The erasing beam is configured to perform erasing while performing tracking control so that the erasing beam always scans the information track.

According to the present invention having the above-described configuration, the erase beam on the record carrier during erasure is controlled so as to always scan over the information track, so that no erase residue occurs.
When a new signal is recorded on the erased information track, a high quality signal can be recorded.

Working Example Hereinafter, the present invention will be described in detail with reference to the drawings. The same numbers are used for the same numbers in the description of the drawings.

FIG. 1 shows an embodiment of the present invention. A light beam 2 generated from a recording / reproducing light source 1 passes through an optical filter 3 and is reflected by a polarization beam splitter 4 to produce a λ / 4 plate 5
(Where λ is the wavelength of the light beam 2) and is converged on the record carrier 7 by the converging lens 6. A spiral groove track (hereinafter referred to as an information track) is provided on the record carrier 7, and the record carrier 7 is attached to a rotation shaft of a disk motor 8 and is rotated at a predetermined rotation speed. The light beam 2 reflected by the record carrier 7 passes through the converging lens 6 and the λ / 4 plate 5 again, and further passes through the polarization beam splitter 4 and is irradiated onto the photodetector 9.

Further, the light beam 11 generated from the erasing light source 10 is reflected by the total reflection mirror 12 and the optical filter 3, is reflected by the polarization beam splitter 4 similarly to the light beam 2, passes through the λ / 4 plate 5, and is converged by the converging lens. It is converged on the record carrier 7 by 6. The light beam 11 reflected by the record carrier 7 passes through the converging lens 6, the λ / 4 plate 5 and the polarization beam splitter 4, and is irradiated onto the photodetector 9.

The wavelength of the light beam 2 generated from the light source 1 and the wavelength of the light beam 11 generated from the light source 10 are different. For example, the wavelength of the light beam 2 is 780 nm and the wavelength of the light beam 11 is 83 nm.
It is 0 nm. The optical filter 3 is configured to pass the light beam 2 and reflect the light beam 11.

The converging lens 6 is separated by the first control element 13, and the first control element 13 can move the converging lens 6 in a direction substantially perpendicular to the information track direction on the record carrier 7 according to the input signal. Is configured. That is, the first control element 13 can move the light beams 2 and 11 focused on the record carrier 7 in a direction substantially perpendicular to the information track direction. Further, the total reflection mirror 12 is attached to the second control element 14, and the second control element 14
Is configured so that the light beam 11 focused on the record carrier 7 can be moved in a direction substantially perpendicular to the information track direction on the record carrier 7 by rotating or translating the total reflection mirror 12.

The light sources 1 and 10, the optical filter 3, the polarization beam splitter 4, the λ / 4 plate 5, the photodetector 9, the total reflection mirror 12, the first control element 13 and the second control element 14 are the transfer table 15
The transfer table 15 is configured to be integrally moved by a third control element 16 such as a linear motor in a direction substantially perpendicular to the information track direction on the record carrier 7.

Recording, reproduction and erasing of signals will be briefly described. The light source 1 is for performing recording and reproduction, and when reproducing a signal recorded on the record carrier 7, the light beam 2 generated from the light source 1 is set to a relatively small constant light amount, for example, the photodetector 9 The reproduction signal is obtained from the output of. When a signal is recorded on the record carrier 7, the intensity of the light beam 2 generated from the light source 1 is modulated according to the signal to be recorded. The light source 10 is used for erasing the signal recorded on the record carrier 7, but is modulated at a higher frequency than the signal recorded on the record carrier 7. The oscillator 17 generates this modulated signal, and sends the signal to the drive circuit 18 that drives the light source 10. An erasing gate signal is input to the input end 19, and when an erasing gate signal, for example, a signal in the HIGH state is input to the input end 19, the light amount of the light beam 11 increases.
The signal recorded on the record carrier 7 is erased. The light beam 11 is modulated according to the signal of the oscillator 17, but there is no problem if it is made sufficiently higher than the signal recorded on the record carrier 7. Furthermore, when the light beam 11 on the record carrier 7 has a shape elongated in the information track direction, even if the light source 10 is modulated at a frequency slightly higher than the signal recorded on the record carrier 7, no erasure spots occur. . Input terminal 19 is L
In the OW state, the light beam 11 has a weak light intensity that does not affect the record carrier 7.

The tracking control for controlling the light beams 2 and 11 focused on the record carrier 7 to scan the information track will be described.

The photodetector 7 has two light receiving areas, and the direction of the dividing line thereof coincides with the information track direction on the record carrier 7. Further, the dividing line of the photodetector 7 is installed so as to divide the light beams 2 and 11 irradiated on the surface thereof into two. One output of the photodetector 9 is a bandpass filter 20.
And the low-pass filter 21, and the other output is input to the band-pass filter 22 and the low-pass filter 23, respectively. The low-pass filters 21 and 23 are for removing unnecessary band noise included in the signal of the photodetector 9 and the modulation component of the light beam 11, and the bandpass filters 20 and 22 are the photodetectors. The oscillating frequency component of the oscillator 17 included in the signal 9 is extracted. The photodetector 9 outputs a signal corresponding to the sum of the light amounts of the light beam 2 and the light beam 11 with which the surface thereof is irradiated.
Only the signal corresponding to the light quantity of the light beam 11 modulated by is output. The bandpass filters 20 and 22 may be simply high-pass filters. The signals of the band pass filters 20 and 22 are input to the rectifiers 24 and 25 for envelope detection, and the signals of the rectifier 24 are input to the differential amplifiers 26 and 27 and the addition circuit 28, and the rectifier 25.
Signal is input to the differential amplifiers 26 and 29 and the adder circuit 28, respectively. The differential amplifier 26 includes rectifiers 24 and 2
The signal corresponding to the difference of the signals of 5 is output, and the adding circuit 28 outputs the signal corresponding to the sum of the signals of the rectifiers 24 and 25.

The signal of the low pass filter 21 is input to the differential amplifier 27, and the differential amplifier 27 outputs a signal corresponding to the difference between the signal of the rectifier 24 and the signal of the low pass filter 21. The signal of the low pass filter 23 is the differential amplifier 2
9 is inputted to the differential amplifier 29, and the differential amplifier 29 outputs a signal corresponding to the difference between the signal of the rectifier 25 and the signal of the low pass filter 23.

The signals of the differential amplifiers 27 and 29 are input to the differential amplifier 30 and the addition circuit 31, respectively, and the differential amplifier 30 outputs a signal corresponding to the difference between the signals of the differential amplifiers 27 and 29, and the addition circuit 31. Outputs a signal corresponding to the sum of the signals of the differential amplifiers 27 and 29.

As will be described in detail later, the differential amplifier 26 outputs a signal indicating the positional deviation between the light beam 11 on the record carrier 7 and the information track, and the differential amplifier 30 outputs the position of the light beam 2 on the record carrier 7 and the information track. A signal indicating the deviation is output.

The signals of the differential amplifier 30 and the adder circuit 31 are respectively input to the divider 32, and the divider 32 outputs the differential amplifier 30.
A signal corresponding to a value obtained by dividing the signal of 1 by the signal of the adding circuit 31 is output. The signal of the divider 32 is applied to the first control element 13 via the switch 33, the phase compensation circuit 34, and the drive circuit 35 for power amplification, and the switch 3
When 3 is short-circuited, the light beam 2 on the record carrier 7 is controlled so as to always scan the information track (this control is called the first tracking control). The phase compensation circuit 34 is for compensating the phase of the first tracking control system.

The signal of the divider 32 is applied to the third control element via the phase compensation circuit 36 and the drive circuit 37 for power amplification. Therefore, when the switch 33 is short-circuited, the third control element 16 controls the current flowing through the first control element 13 to be zero on average, that is, the first control element 13 is centered around the natural state. It is controlled to move (this control is called transfer control). The phase compensation circuit 36 is for compensating the phase of the transfer control system. The switch 33 is for disabling the first tracking control and the transfer control.

The operation of the divider 32 will be described. When the light quantity of the light beam 2 generated from the light source 1 becomes N times, the output of the differential amplifier 30 with respect to the unit track deviation between the light beam 2 on the record carrier 7 and the information track (this is called track deviation detection sensitivity). ) And the output of the adder circuit 31 are also multiplied by N. Therefore, even if the light quantity of the light beam 2 changes, the output of the divider 32 with respect to the unit track deviation between the light beam 2 on the record carrier 7 and the information track does not change, and the loop gain is kept constant. The tracking control of is extremely stable.

The second tracking control for controlling the light beam 11 on the record carrier 7 to scan the information track will be described.

The signal of the differential amplifier 26 and the signal of the adder circuit 28 are respectively input to the divider 38, and the divider 38 outputs a signal corresponding to a value obtained by dividing the signal of the differential amplifier 26 by the signal of the adder circuit 28. Output. This signal is passed through the switch 39 for disabling the second tracking control, the phase compensation circuit 40 for compensating the phase of the second tracking control system, and the drive circuit 41 for power amplification to the second It is added to the control element 14. Therefore, the second control element 14
Are controlled so that the light beam 11 on the record carrier 7 always scans the information tracks. The operation of the divider 38 is the same as that of the divider 32, and therefore its explanation is omitted. Four
2 is an input terminal for a signal for opening and closing the switch 32, 4
Reference numeral 3 is an input terminal for a signal for opening and closing the switch 39.

The reason why the second tracking control is necessary
It will be described with reference to the drawings.

FIG. 2 is a view showing the states of the light beams 2 and 11 on the recording medium 7 in a slightly exaggerated manner. FIG. A is a sectional view when the record carrier 7 is cut in the radial direction, FIG. C shows the spot state of the light beams 2 and 11 on the record carrier 7 when viewed from the direction in which the light beam is irradiated.

The record carrier 7 is formed by forming a recording material layer 52 on a base material 51 having a groove-shaped information track 54 having a depth d on the surface by means such as vapor deposition, and providing a protective layer 53 thereon.
If the refractive index of the base material 51 is n and the wavelength of the light beam 2 is λ, the groove depth d is approximately d = λ / 8n.

FIG. B shows a state in which the axis 55 connecting the central rays of the light beam 2 and the light beam 11 on the record carrier 7 and the direction of the information track 54 are parallel, and therefore the first tracking control is activated. If the beam 2 is controlled to scan on the information track 54, the light beam 11 inevitably scans on the information track 54.

FIG. C shows a state in which the axis 55 and the information track 54 are not parallel to each other and have a minute angle θ. In such a case, the first tracking control is operated to cause the light beam 2 to transmit information. Even if the light beam 11 is controlled to scan on the track 54, the light beam 11 does not accurately scan on the information track 54 and a track shift occurs.

Since the first control element 13 moves the light beams 2 and 11 in a direction perpendicular to the direction of the information track 54, if the axis 55 and the direction of the information track 54 are adjusted to be parallel as shown in FIG. The second tracking control described above is unnecessary. However, if the pitch of the information tracks 54 is 1.6 μm and the width is 0.6 μm, the light beam 11
The deviation between the central ray of light and the center of the information track 54 is ± 0.0
It is necessary to be 5 μm or less, and since there is an angular variation due to eccentricity of the record carrier 7, play of the transfer table 15, etc., the direction of the axis 55 and the information track 54 is not parallel as shown in FIG. Even if the light beam 2 is controlled to scan the information track 54 by operating the first tracking control, the phenomenon that the light beam 11 does not accurately scan the information track 54 occurs.

For example, in FIG. C, if the distance 1 between the centers of the light beam 2 and the light beam 11 is 40 μm, the light beam 2 accurately scans the information track 54, and the center of the light beam 11 is 0.05 μm from the information track 54. The shift angle θ ₀ is θ ₀ = sin ⁻¹ (0.05 / 40) = 1.25 mrad (0.07 °).

Assuming that the eccentricity of the record carrier 7 is a sine wave based on the rotation frequency, the eccentricity amount of the information track 54 located at a radius r from the center of the record carrier 7 is Δr, and the disc motor 8 is in the plane of the record carrier 7. When a line perpendicular to the straight line passing through the center of rotation of the maximum angle between the tangent at the intersection of the straight line and the information track 54 and ^{_{θ 1 θ 1 = tan -1 (}} Δr / r) , and becomes at least θ ₁ ≦ θ ₀ Therefore, if r = 25 mm, the allowable eccentricity Δr must be 30 μm or less.

However, as described above, there is a change in angle due to play of the transfer table 15 and a change in temperature with time due to thermal expansion of the optical head, etc., and without the second tracking control, not only the record carrier and the device become expensive, but also However, the reliability of the device also decreases.

Detection of track deviation in the embodiment of FIG. 1 will be described with reference to FIG.

In FIG. 3, FIG. A is an enlarged view of the record carrier 7, and FIGS. B and C are the signal level on the vertical axis and the position of the light beam on the horizontal axis. It shows both signals of the photodetector which are output when the information track 54 is crossed in a state where a predetermined amount of erasing light is set.

Reference numeral 61 is a reference level of the output signal of the photodetector 9, 62 is a signal output to the photodetector 9 when the light beam 2 crosses the information track 54, and 63 is a light beam 11 of the information track 5.
The signals output to the photodetector 9 when crossing 4 are shown.

Since the bandpass filters 20 and 22 of FIG. 1 pass only the signal 63, the differential amplifier 26, which outputs the difference between the signals of the bandpass filters 20 and 22 rectified by the rectifiers 24 and 25, is provided on the record carrier 7. A signal representing the positional deviation between the light beam 11 and the information track 54 is output.

Also, the low pass filters 21 and 23 have signals 62 and 63.
Since the low-frequency component of the composite signal of FIG.
And a signal such as the signal 64 shown by the alternate long and short dash line in FIG.

The differential amplifier 27 is configured to take the difference between the signal of the low pass filter 21 and the signal of the rectifier 24 and output a signal corresponding to only the light beam 2. In addition, the differential amplifier 2
Similarly, the signal of the low pass filter 23 and the rectifier 2
The signal of 5 is taken out, and the signal corresponding to only the light beam 2 is output.

Therefore, the differential amplifier 30 outputs a signal indicating the positional deviation between the light beam 2 on the record carrier 7 and the information track 54, and the adder circuit 31 outputs a signal corresponding to the light quantity of the light beam 2 on the photodetector 9. .

The reason why the light source 10 outputs a weak light amount that does not affect the record carrier 7 when the input end 19 is in the LOW state in the embodiment of FIG. 1 will be described.

When the second tracking control is operated, it takes time for the control system to stabilize, and it is necessary to start the erasing at least after the second tracking control stabilizes. Therefore, in order to stabilize the second tracking control, the light source 10 is driven so as to emit a weak light amount that does not affect the record carrier 7, and a predetermined light amount is emitted after the second tracking control is stabilized. Light source 10
Must be driven to erase the signal recorded on the desired information track.

The need for erasure cannot be predicted. Therefore, in a normal state, the amount of light emitted from the light source 10 is set to zero, and the second
If the tracking control of No. 2 is set in the inactive state, it takes a long time to pull in the above-mentioned second tracking control when there is a need to erase it, and thus a waiting time for rotation may occur, resulting in a long processing time. . In the embodiment of FIG. 1, the light source 10 is driven so as to output a weak light amount regardless of whether the second tracking control is performed, and the second tracking control is also activated when the first tracking control is activated. With this configuration, the above-mentioned drawbacks can be eliminated.

Further, when the second tracking control is operated in the inoperative state of the first tracking control, the second control element is damaged, so that the second tracking control is performed in the inoperative state of the first tracking control. It is desirable to configure so that does not work.

The relationship between the first and second tracking controls in the embodiment shown in FIG. 1 will be described below.

Since the first tracking control is performed by moving the converging lens 6 so that the light beam 2 on the record carrier 7 always scans the information track, the light beam 11 on the record carrier 7 is also of course approximately the same. Scan over information tracks.

However, as described above, although the light beam 11 may be deviated from the information track due to various reasons, the second control element 14 is driven so that the light beam 11 accurately scans the information track. Thus, the second tracking control is performed.

Therefore, the first control element 13 controls the light beam 2 on the record carrier 7.
And 11 are moved so that the second control element 14 moves only the light beam 11 on the record carrier 7.

Since both the light beams 2 and 11 need to accurately follow the eccentricity of the information track, the first control element 13
Has a large moving range, and requires, for example, about ± 300 μm. However, since the amount of deviation of the light beam 11 with respect to the information track in the state where the light beam 2 accurately scans the information track is small, the movement range of the second control element 14 may be small.

Since both the light beams 2 and 11 need to scan the same track, the moving range of the second control element 14 should be small, and the information track different from the information track being scanned by the light beam 2 (for example, adjacent tracks). In order to prevent the light beam 11 from scanning on the information track), the moving range of the light beam 11 on the record carrier 7 moved by the second control element 14 may be ± P / 2 or less. desirable. Where P is the pitch of the information tracks on the record carrier 7.

The track deviation that must be corrected by the second tracking control is almost DC-like and has a rotational component of the record carrier 7. Therefore, the response of the second tracking control system is better than that of the first tracking control system. It is desirable to make it low and to not respond to a dropout or the like on the record carrier 7.

Further, when the characteristic vibration frequency of the second control element 14 is made higher than the characteristic vibration frequency of the first control element 13 and the response band of the second tracking control system is taken as much as necessary, the record carrier 7 It is desirable that the loop gain at the rotation frequency of is smaller than the loop gain of the first tracking control system so that it does not sensitively respond to a dropout or the like on the record carrier 7. When the moving range of the second control element 14 is configured to be limited to a very small range, if the loop gain in the low range is increased, the pull-in becomes unstable. It is desirable not to excessively increase the loop gain in the low frequency range.

To explain this in more detail, for example, the record carrier 7
The pitch of the upper information track is 1.6 μm and the width is 0.6 μm.
m, the maximum movement range of the second control element is ± 0.8 μm, and the loop gain of the low frequency band of the second tracking control system is 40 d.
When the second tracking control is operated in the state where the light beam 11 on the record carrier 7 and the information track have a track deviation of 0.3 μm, the second control element 14 momentarily records 30 μm. A signal is applied which causes the light beam 11 on the carrier 7 to move, which signal causes the second control element 14 to generate an overshoot and the second control element 14
The second tracking control system may become unstable due to collision with the limiting means that limits the moving range of. Therefore the second
If the loop gain of the tracking control system is not excessively increased, and the loop gain is reduced when pulling in, and the loop gain is increased after the second tracking control stabilizes, pulling in becomes more stable. To do.

Further, when the light beam 11 on the record carrier 7 is located in the vicinity of just above the information track, it is detected from the signal of the differential amplifier 26 or the divider 38, and the second tracking control is activated at this moment. With this configuration, the pull-in of the second tracking control can be further stabilized. If the detection that the light beam 11 on the record carrier 7 is located near the information track is detected from the level of the signal of the divider 38, the detection level varies depending on the light amount of the light beam 11. Can be prevented.

When operating the first tracking control, the second tracking control, and the second tracking control, first the first tracking control is operated, and then the second tracking control is operated after the first tracking control is stabilized. With this configuration, the second tracking control can be more stably and surely drawn into the desired information track.

Further, if the signal level of the differential amplifier 26 or the divider 38 detects that the positional deviation between the light beam 11 and the information track on the record carrier 7 becomes a predetermined value or less, the erasure is performed. Sexuality goes up.

Further, it is detected from the signal level of the differential amplifier 26 or the divider 30 that the light beam 11 on the record carrier 7 has a track shift exceeding a predetermined value during erasing, and the erasing is immediately stopped, and the second erasing is performed. If the erasing is performed again after the tracking control of (1) is stabilized, the signal recorded on another track is not erased, and the reliability is remarkably improved.

Further, it is detected from the signal level of the differential amplifier 30 or the divider 32 that the light beam 2 on the record carrier 7 causes a track shift exceeding a predetermined value and the first tracking control becomes unstable. If the second tracking control is immediately disabled and the erasing is stopped during the erasing and the erasing is performed again after the erasing is stabilized, the second tracking control and the erasing can be performed with high reliability. it can.

The reason why the wavelength of the light beam 11 generated from the light source 10 is shorter than the wavelength of the light beam 2 generated from the light source 1 in the first embodiment will be described.

Generally, the longer wavelengths are more difficult to focus than the shorter wavelengths, and the light beams 2 and 1 converged by the converging lens 6
It is known that assuming that the diaphragm diameter of ₁ is φ ₁ and φ ₂ , φ ₁ = K · λ ₁ / NA and φ ₂ = K · λ ₂ / NA. Where K is the constant, λ ₁ is the wavelength of the light beam 2, λ ₂ is the wavelength of the light beam 11, and NA is the numerical aperture of the converging lens 6.

Therefore, the light beam 2 having the same beam diameter is converged on the converging lens 6.
When 11 and 11 are made incident, the wavelength of the light beam 2 is shorter than the wavelength of the light beam 11, so that the light beam 2 is narrowed better. For recording or reproducing a signal, it is preferable that the beam diameter is small, and for erasing, erasing a little wider than the recorded signal width enables more stable erasing.

Therefore, if the wavelength of the light beam 2 is set shorter than the wavelength of the light beam 11 as in the embodiment of the present invention, high-quality recording / reproducing and erasing can be performed.

Although the present invention has been described in detail above, the present invention is not limited to the embodiments.

For example, the present invention can be applied to an apparatus configured so that a recording light beam and a reproducing light beam are converged on a record carrier and whether or not a signal is accurately recorded on the record carrier can be simultaneously recorded. Can be adapted.

Further, an apparatus configured so that three or more light beams, for example, an erasing light beam, a recording light beam and a reproducing light beam are converged on the record carrier so that erasing, recording and confirmation of recording can be simultaneously performed. The present invention can also be applied to.

EFFECTS OF THE INVENTION According to the present invention, erasing is performed while controlling the erasing beam on the record carrier so as to always scan over the information track, so that the signal recorded on the desired information track is erased accurately and reliably. Therefore, the reliability of the device can be significantly improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention, and FIG. 2 is a diagram showing a light beam on a record carrier for explaining the reason why the erase beam causes a track shift in the absence of the second tracking control. FIG. 3 is a diagram showing the output signal of the photodetector for explaining the track deviation detection. 1, 10 ... Light source, 2, 11 ... Light beam, 3 ... Optical filter, 6 ... Converging lens, 7 ... Record carrier, 9 ...
... Photodetector, 12 ... Total reflection mirror, 13 ... First control element, 14 ... Second control element, 17 ... Oscillator, 18,
35,41 ... Driving circuit, 20, 22 ... Band pass filter, 21, 23 ... Low pass filter, 24, 2
5 ... Rectifier, 26, 27, 29, 30 ... Differential amplifier, 28, 31 ... Adder circuit, 32, 38 ... Divider,
33, 39 ... Switches 34, 40 ... Phase compensation circuit.

Claims (22)

[Claims] 1. A first light source for generating a first light beam, a second light source for generating a second light beam, and the first and second light beams on a record carrier. Means for converging and irradiating on the record carrier, and first moving means for moving the first and second light beams on the record carrier in a direction substantially perpendicular to the direction of the information track on the record carrier. And second moving means for moving the second light beam on the record carrier in a direction substantially perpendicular to the information track direction on the record carrier, and the first light beam and information on the record carrier. A first track deviation detecting means for detecting a track position deviation; a second track deviation detecting means for detecting a position deviation between the second light beam and the information track on the record carrier; and the first track deviation. The first moving means is driven in response to a signal from the detecting means, First control means for serial first light beam is controlled to always scans on the information track,
The second moving means is driven in response to the signal of the second track deviation detecting means, and the second light beam on the record carrier is controlled so as to always scan the information track. An optical recording / reproducing apparatus comprising: a control means, wherein the first control means is configured so that the second control means does not operate when the first control means is in an inoperative state. 2. The optical recording / reproducing apparatus according to claim 1, wherein the light quantity of the second light beam is set to a weak light quantity which does not affect the record carrier in a normal state. 3. The optical recording / reproducing apparatus according to claim 1, wherein the second control means operates after the first control means operates. 4. An optical recording / reproducing apparatus according to claim 3, wherein the second control means operates after the first control means stabilizes. 5. The second control means is operated by setting the light amount of the second light beam to a weak light amount which does not affect the record carrier,
5. The optical recording / reproducing apparatus according to claim 4, wherein the second control means is configured to set the light quantity of the second light beam to a predetermined light quantity that affects the record carrier after the second control means is stabilized. apparatus. 6. The second control means is considered to be stable when the signal level of the second track deviation detecting means falls within a predetermined value range, and the light quantity of the second light beam is recorded on the record carrier. The optical recording / reproducing apparatus according to claim 5, wherein the optical recording / reproducing apparatus is configured so as to have a predetermined amount of light that has an influence. 7. A structure in which the first control means is regarded as stable and the second control means operates when the signal level of the first track deviation detection means falls within a predetermined value range. The optical recording / reproducing apparatus according to claim 4, characterized in that. 8. An optical recording / reproducing apparatus according to claim 1, wherein the second control means is made inoperative when the first control means becomes unstable. . 9. When the signal level of the first track deviation detecting means exceeds a predetermined value, it is considered that the first control means has become unstable, and the second control means is made inoperative. The optical recording / reproducing apparatus according to claim 8, wherein the optical recording / reproducing apparatus is configured. 10. The light quantity of the second light beam immediately when the first control means becomes unstable in a state where the light quantity of the second light beam is a predetermined light quantity affecting the record carrier. The optical recording / reproducing apparatus according to claim 1, wherein the optical recording / reproducing apparatus is configured so as to have a weak light amount that does not affect the record carrier. 11. When the signal level of the first track deviation detecting means exceeds a predetermined value, it is considered that the first control means becomes unstable, and the light quantity of the second light beam is applied to the record carrier. 11. The optical recording / reproducing apparatus according to claim 10, wherein the optical recording / reproducing apparatus is configured so as to have a weak light amount that does not affect. 12. The light quantity of the second light beam immediately when the second control means becomes unstable in a state where the light quantity of the second light beam is a predetermined light quantity affecting the record carrier. The optical recording / reproducing apparatus according to claim 1, wherein the optical recording / reproducing apparatus is configured so as to have a weak light amount that does not affect the record carrier. 13. When the signal level of the second track deviation detecting means exceeds a predetermined value, it is considered that the second control means has become unstable, and the light quantity of the second light beam is applied to the record carrier. 13. The optical recording / reproducing apparatus according to claim 12, wherein the optical recording / reproducing apparatus is configured to have a weak light amount that does not affect the light intensity. 14. The device according to claim 1, wherein the second control means is operated in a state where the second light beam on the record carrier scans the vicinity of directly above the information track. The optical recording / reproducing apparatus according to item 1. 15. The second control means is operated by detecting from the signal level of the second track deviation detecting means that the second light beam on the record carrier is scanning in the vicinity of just above the information track. The optical recording / reproducing apparatus according to claim 14, wherein the optical recording / reproducing apparatus is configured as described above. 16. An optical recording / reproducing apparatus according to claim 1, wherein the low-pass loop gain of the second control means is smaller than the low-pass loop gain of the first control means. . 17. An optical recording / reproducing apparatus according to claim 1, wherein the responsiveness of the second control means is lower than that of the first control means. 18. The characteristic vibration frequency of the second moving means is set to the first
The optical recording / reproducing apparatus according to claim 1, wherein the moving means is higher than the moving means. 19. The first control means is operated while the loop gain of the second control means is lowered, and then the loop gain is increased. An optical recording / reproducing apparatus as described in the item. 20. An optical recording / reproducing apparatus according to claim 19, wherein the loop gain is increased after the second control means is stabilized. 21. When the signal level of the second track deviation detecting means falls within a predetermined value range, the second control means is considered to be stable, and the loop gain is increased. The optical recording / reproducing apparatus according to claim 20, which is characterized. 22. When the wavelength of the first light beam wavelength lambda ₁ second light beam and lambda _2, lambda _{1 <optics} lambda ₂ and the possible features and claims ranging claim 1 wherein the Recording / playback device.