JP2003085845A - Magneto-optical recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magneto-optical recording and reproducing device of a pulse drive magnetic modulation overwrite system emitting a laser beam without mitigation vibration by light emission of recording power. SOLUTION: The magneto-optical recording and reproducing device 10 of the pulse drive magnetic modulation overwrite system is provided with a laser 35, a driving means supplying a driving current to the laser 35 and a control means 19 controlling the driving current by outputting control signals to the driving means successively in one channel clock when recording data to a zero level of not making the laser 35 emit light, a first level of making the laser 35 emit the light with an emitted light intensity not making a direction of a magnetic field on a recording film of a recording medium changeable by an applied magnetic field and a second level of making the laser 35 emit the light with the emitted light intensity making the direction of the magnetic field on the recording film changeable by the applied magnetic field.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse drive magnetic modulation overwrite type magneto-optical recording / reproducing apparatus capable of supplying a driving current to a laser at three levels of current values during one channel clock.

[0002]

2. Description of the Related Art Recording systems for magneto-optical disks include optical modulation systems and magnetic modulation systems. The optical modulation method first irradiates a high-power laser beam while applying a constant magnetic force to align the recording film with a constant magnetic force, and then applies a magnetic force opposite to the previous one, and modulates the laser beam according to the information to be recorded. This is a method for recording information by (light emission, extinction). On the other hand, the magnetic modulation method is a method for recording information by irradiating a high-power laser and modulating the magnetic force according to the information to be recorded. The magnetic modulation method provides a recording mark (recording pattern) that contrasts S and N, and since the boundary between S and N also has a clean bow shape, it is a minute recording mark with less jitter than the optical modulation method. Can be accurately recorded.

This magnetic field modulation system further includes a simple magnetic field modulation overwrite system and a pulse drive magnetic field modulation overwrite system. The simple magnetic field modulation overwrite method is
This is the method described above. The pulse drive magnetic field modulation overwrite method is a method of recording information by irradiating a high-power laser in a pulse shape and modulating magnetic force according to information to be recorded. The pulse drive magnetic field modulation overwrite method is
Compared with the simple magnetic field modulation overwrite method, the shape of the recording mark on the magneto-optical disk becomes closer to a perfect circle and the edge of the recording mark becomes clear, so that there is an advantage that the density can be easily increased.

FIG. 6 is a diagram showing the relationship between the recording speed and the laser emission waveform in the pulse drive magnetic field modulation overwrite method.

6A and 6B show the drive current and the laser emission waveform in the low speed recording, respectively, and FIGS. 6C and 6D show the drive current and the laser emission waveform in the high speed recording, respectively. In addition, the horizontal axis of each figure of FIG. 6 is time, and the horizontal axis of FIG.
The vertical axis of C represents current value, and the vertical axes of FIGS. 6B and 6D represent emission intensity.

In the pulse drive magnetic field modulation overwrite system, the one-channel clock is used for fixing the formed recording mark and the time for which the laser emits light to heat the recording film of the magneto-optical disk to form the recording mark. And the time to turn off the laser. Therefore, as shown in FIGS. 6A and 6C, the drive current for making the laser emit light rises from a zero level for a certain period of time to a predetermined level (recording drive level) in a one-channel clock, and is maintained for a certain period of time and then returns to a zero level. It is a falling rectangular pulse. The laser is driven by such a rectangular pulse, but the laser emission waveform is known to be a relaxation oscillation that overshoots and vibrates at the rising edge of the pulse, as shown in FIGS. 6B and 6D. . This overshoot is a phenomenon that occurs when the photon density rises at a speed much higher than the injected carrier density when the injected carriers of the drive current continue to increase beyond the threshold value at which the laser emission state is reached. The amount is very difficult to control.

Recording power P due to this overshoot
1 is the error of the recording power. In the case of low speed recording, the recording power P1 due to overshoot is a few percent of the total recording power and is within the recording power margin, so it can be ignored.

[0008]

By the way, there is a tendency that the channel clock becomes faster and the pulse time becomes shorter due to the recent demand for higher speed recording / reproducing of a magneto-optical disk. In such a case, the recording power P1 due to overshoot becomes 10% or more of the total recording power, and the recording power margin tends to decrease due to the recent increase in density, so that the recording power P1 is out of the recording power margin. . For this reason, there is a problem in that stable recording cannot be performed due to cross write and jitter in which recording marks overlap between adjacent tracks.

On the other hand, in order to solve this problem, a method of monitoring each pulse waveform and controlling at the same response speed as the pulse can be considered. This method requires all the control circuits to operate at high speed, requires a light-receiving element with a small electric capacity, requires an extra component such as a lens to focus light on the small light-receiving element, and requires feedback. It is necessary to shorten the route of. Therefore, it is necessary to mount extra parts, control circuits, and the like on the optical pickup, which causes a problem that the miniaturization of the optical pickup is hindered. Then, there is a problem that the temperature of the optical pickup rises due to the heat generation of the circuit. Furthermore, as high-speed operation requires special parts that are not general-purpose products,
There is also the problem of increased costs.

Therefore, an object of the present invention is to provide a magneto-optical recording / reproducing apparatus capable of controlling the recording power in the pulse drive magnetic field modulation overwrite system.

[0011]

According to a first means of the present invention, in a magneto-optical recording / reproducing apparatus of a pulse drive magnetic modulation overwrite type, a laser for emitting a laser beam and a drive for supplying a drive current to the laser are provided. Means, a zero level for not emitting the laser, a first level for emitting the laser with an emission intensity that does not change the direction of the magnetic field in the recording film of the recording medium by the applied magnetic field, and a magnetic field in the recording film. The driving is performed by sequentially outputting a control signal to the driving means during a one-channel clock at the time of recording data to a second level that causes the laser to emit light with an emission intensity that makes the direction changeable by the applied magnetic field. And a control means for controlling the current.

According to a second aspect of the present invention, in a magneto-optical recording / reproducing apparatus of the pulse drive magnetic modulation overwrite type, a laser emitting a laser beam, a drive means for supplying a drive current to the laser, A detection unit that detects the emission intensity of the laser beam emitted by the laser and a control unit that controls the drive current by outputting a control signal to the drive unit are provided, and the control unit is reproducing data from a recording medium. Is adjusting the control signal on the basis of the output of the detecting means so as to have a light emission intensity for reproducing the data of the recording medium, and holding the adjusted control signal after the reproduction is finished, and recording the data on the recording medium. Is a control signal that is a drive current that does not cause the laser to emit light, the held control signal, and the emission intensity for recording data on the recording medium. Constructed by controlling the drive current control signal adjusted based on the output of sea urchin said detection means by outputting to the drive unit in order during one channel clock.

In such a magneto-optical recording / reproducing apparatus, since the laser emits a laser beam, the laser beam is preliminarily emitted before raising the emission intensity of the laser beam to the recording power level in a range that does not affect the recording film of the recording medium. When the emission intensity is raised to the recording power level, it never overshoots the recording power level.

Therefore, the emission intensity of the laser can be appropriately controlled to the specified recording power level.
The recording mark can be stably formed by pulse driving.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. In each figure, the same components are designated by the same reference numerals and the description thereof will be omitted.

FIG. 1 is a diagram showing the structure of a recording / reproducing apparatus.

In FIG. 1, a recording / reproducing apparatus 10 includes a chuck plate 11, a turntable 12, a spindle motor 13, a spindle motor driver 14, a guide rail 15, a magnetic field modulation driver 16, a magnetic field modulation head 17,
The optical pickup 18, a laser drive control circuit 19, a biaxial mechanism driver 20, a sled motor 21, a sled motor driver 22, a signal processing circuit 24, an RF amplifier 25, and a system control circuit 26 are provided.

The disk-shaped recording medium 101 is chucked by a turntable 12 and a chuck plate 11 which are connected to a rotary shaft of a spindle motor 13.

The recording medium 101 is, for example, a magneto-optical disk. The recording surface has a plurality of concentrically arranged tracks and a plurality of sector addresses in the radial direction. The sector address is information indicating the position of the recording area when one track is divided into a plurality of recording areas in the circumferential direction. The recording / reproducing device 10 specifies a recording area from the track number and sector address assigned to each track, and reads / writes data in the recording area.

The spindle motor 13 receives the spindle servo of the system control circuit 26 via the spindle motor driver 14, and the rotation speed is constant (CAV, constant a).
The recording medium 101 is rotationally driven at a predetermined angular velocity by the ngular velocity method. The present invention is directed to the recording medium 10.
Since it can be applied regardless of the rotation speed of 1,
A constant linear velocity (CLV) method or the like may be used.

The optical pickup 18 uses a laser beam from a semiconductor laser (hereinafter abbreviated as "LD") 35 described later to access a track of the recording medium 101 to read / write data. The laser drive control circuit 19 controls ON / OFF of the LD 35. Regarding the optical pickup 18 and the laser drive control circuit 19,
It will be described later.

When recording data on the recording medium 101, the magnetic field modulation head 17 applies a magnetic field of a predetermined intensity to the recording medium 1.
01, magnetism is generated. The direction of the magnetic field follows the data to be recorded on the recording medium 101,
It is controlled by the signal processing circuit 24 via the magnetic field modulation driver 16. The magnetic field modulation head 17 is arranged so that the recording medium 101 is present between the objective lens of the optical pickup 18 and the magnetic field modulation head 17.

The sled motor 21 is driven and controlled by the system control circuit 26 via the sled motor driver 22, and the optical pickup 18 together with the magnetic field modulation head 17 is driven.
Are transported in the horizontal direction (radial direction) of the recording medium 101 along the guide rails 15. The thread motor 21 is preferably a stepping motor, for example, from the viewpoint that the relationship between the amount of movement of the optical pickup 18 itself and the amount of drive of the thread motor 21 can be easily measured without using a special detector. It is also possible to use a normal motor by using a detector that determines the relationship between the transfer amount of the optical pickup 18 itself and the drive amount of the sled motor 21.

The laser light emitted from the optical pickup 18 moves in the horizontal direction (radial direction) of the recording medium 101 using the tracking coil and / or the sled motor 21 in the optical pickup 18.

The system control circuit 26 is a microprocessor (MPU) having a memory, and controls the operation of the entire recording / reproducing apparatus 10 such as information reading / writing, focus servo, tracking servo, and spindle servo, and each section.

Next, the configurations of the optical pickup 18 and the laser drive control circuit 19 will be described.

FIG. 2 is a diagram showing the configuration of the optical pickup and the laser drive control circuit.

The optical pickup 18 includes an objective lens 31,
The rising mirror 32, the beam splitter 33, the collimator lens 34, the LD 35, the substrate 36, the light receiving element 37, a tracking coil (not shown), a focus coil (not shown), and the like are included.

The tracking coil and the focus coil constitute a biaxial mechanism capable of moving the objective lens 31 in two orthogonal directions. The tracking coil is
Move the objective lens 31 in the horizontal direction of the recording medium 101,
The focus coil connects the objective lens 31 to the recording medium 101.
In the vertical direction (direction in which the surface of the recording medium 101 comes close to and away from). The tracking coil and the focus coil are drive-controlled by the system control circuit 26 via the biaxial mechanism driver 20 to perform tracking and focusing.

The LD 35 is a light source for recording and reproducing data on the recording medium 101, and emits laser light having a predetermined wavelength. The emitted laser light is collimated by the collimator lens 34, and then the beam splitter 3
At 3, a part of the light is incident on the light receiving element 37, and at the other part, most of the other light is reflected by the rising mirror 32 toward the recording medium 51 side by 90 degrees, focused by the objective lens 31, and incident on the recording medium 101.

The light receiving element 37 converts the received laser light into an electric signal according to its intensity, and the laser drive control circuit 19
Low pass filter (hereinafter abbreviated as "LPF").
It outputs to 49. For example, a photodiode.

On the other hand, the incident laser light raises the temperature of the recording medium 101 when recording data on the recording medium 101. The heated recording area of the recording medium 101 is magnetized according to the direction of the magnetic field applied at that time, and data is recorded. In addition, the incident laser beam is used for recording data on the recording medium 1.
In the case of reading from 01, the plane of polarization is changed according to the data recorded on the recording medium 101 and reflected. The reflected light is incident on a photo detector IC (not shown) via the objective lens 31 and the like, the reflected light is detected, and an electric signal is output.

The electrical signal from the photo detector IC is
The focus signal, the tracking signal, and the reproduction data signal are input to the RF amplifier 25. The focus signal is generated by, for example, the astigmatism method or the Foucault method. The tracking signal is, for example, a beam method, push-pull method, DPD (differential phase det).
section) method, DPP (differential push-pull) method, or the like.

The focus signal and the tracking signal are input to the system control circuit 26 and used for the focus servo and the tracking servo. The reproduced data signal is input to the signal processing circuit 24. The signal processing circuit 24 performs necessary signal processing such as decoding and error correction on the reproduced data signal, and outputs the data recorded on the recording medium 101.

The board 36 is a circuit board on which the LD 35 and a current drive circuit for driving the LD 35 are arranged. The current drive circuit supplies a drive current to the LD 35 as described later according to the control signal from the laser drive control circuit 19.

The optical pickup 18 and the laser drive control circuit 19 are connected by a flexible cable. As described above, the optical pickup 18 and the laser drive control circuit 19 can be separately arranged in the recording / reproducing apparatus 10, so that the movable optical pickup 18 can be made compact and lightweight.

The laser drive control circuit 19 comprises a timing generation circuit 41, switches 42, 45, 47, an A level setting circuit 46, a B level setting circuit 48, a control circuit 43 and an LPF 49.

The LPF 49 is a filter for averaging the electric signal of the light receiving element 37, and its output is input to the A level setting circuit 46 and the B level setting circuit 38.

The cutoff frequency of the LPF 49 is, for example, about 1/100 of the channel clock. Therefore, even if the LD 35 is pulse-driven, the electric signal smoothed by the LPF 49 can be obtained, so that the emission level can be monitored at a response speed of about 1/100 of the channel clock.

Here, the adjustment of the A level (reproducing power level) and the B level (recording power level) of the LD 35 depends on the influence of the reflected light of the recording medium 101, the variation of the emission level due to the temperature change, and the change over time. Since it is originally performed to absorb the fluctuation of the light emission level,
It is a variation factor of about Hz. For example, when the channel clock is 20 MHz, the response speed is 200 kHz, which is 1/100 of 20 MHz, and the light emission level of the LD 35 can be controlled at a sufficient response speed.

The LPF is composed of the capacitance of the light receiving element 37 itself and the resistor for converting the current value of the light receiving element 37 into a voltage value.
Therefore, the LPF 49 may be omitted if the response speed is a cutoff frequency similar to that of the LPF 49.

The A level setting circuit 46 receives the signal b from the control circuit 43 and the output of the LPF 49 as the A level target value a, and eliminates the difference between them.
Of the switch 3 and the A-level control signal is held by a sample hold circuit or the like.
5 is output.

The A-level control signal has a reproduction power level L required for reproducing data from the recording medium 101.
This is a control signal for causing the drive circuit of the substrate 36 to generate a drive current for causing the D35 to emit light. The reproduction power level is a power level that does not substantially change the state of the recording film on the recording medium 101. Then, as will be described later, the A-level control signal supplies a drive current for causing the LD 35 to emit light at the preliminary light emission level necessary for preliminary light emission.
It is also a control signal generated by the driving circuit of No. 6. LD35
By preliminarily emitting light, the relaxation oscillation is prevented when the LD 35 is caused to emit light at the recording power level.

The B level setting circuit 48 receives the signal d from the control circuit 43 and the output of the LPF 49 as the B level target value b and eliminates the difference between them.
The control signal of the B level is held and output to the switch 37.

The B-level control signal is the LD at the recording power level necessary for recording data on the recording medium 101.
This is a control signal for causing the drive circuit of the substrate 36 to generate a drive current for causing the light emission of the light source 35.

A zero-level control signal is input to the switch 32, and according to the timing generated by the timing generation circuit 31 together with the switches 35 and 37,
Turns on (closed) and off (open). The zero-level control signal is not limited to the voltage of 0 V (zero volt), and may be in the range in which the LD 35 does not emit light.

The control signals of each level from the switch 32, the switch 35 and the switch 37 are input to the substrate 36, and the drive current circuit generates a drive current according to each level according to these control signals. The LD 35 emits 0 level light (that is, a state in which it does not emit light) according to the drive current,
Light is emitted at either the reproduction power level (preliminary light emission level) or the recording power level.

Next, the operation of the LD 35 when recording data on the recording medium 101 will be described.

FIG. 3 is a diagram showing a control timing chart of each level setting circuit.

FIG. 4 is a diagram showing a laser drive current and a laser emission waveform during reproduction.

FIG. 5 is a diagram showing a laser drive current and a laser emission waveform during recording.

The horizontal axis of FIG. 3 is time. The vertical axis of the laser drive current in FIGS. 4 and 5 is the current value, and the horizontal axis is time. The vertical axis of the laser emission waveform in FIGS. 4 and 5 is the amount of light emission, and the horizontal axis is time.

3 to 5, the recording / reproducing apparatus 1
When recording data on the recording medium 101, 0 needs to reproduce the sector address in order to record the data in a predetermined recording area. Therefore, as shown in FIG. 3A, reproduction, recording, reproduction, and recording are performed. , ... operates like.

During reproduction, the signal a becomes high level as shown in FIG. 3B, and the signal c becomes low level as shown in FIG. 3C. Therefore, during reproduction, the A level setting circuit 46 operates and the B level setting circuit 48 does not operate. Then, during reproduction, the timing generation circuit 41
A control signal is output to the switch 32, the switch 35, and the switch 37 so that only the switch 35 is turned on by the control signal from the control circuit.

Therefore, a feedback loop consisting of the PD 37, the LPF 49, the A level setting circuit 46, the switch 35, the substrate 36, the LD 35, the collimator lens 34 and the beam splitter 33 is formed. With this feedback loop, the A level setting circuit 46 generates an A level control signal using the signal b as a reference signal. This A
The level control signal is input to the current drive circuit of the substrate 36, and the current drive circuit generates a reproduction drive level current as shown in FIG. 4A. This reproduction drive level current is LD
Then, the LD 35 starts to emit light at the reproduction power level as shown in FIG. 4B. Here, since the reproduction drive level current is input to the LD 35 stepwise as shown in FIG. 4A, the LD 35 causes relaxation oscillation as shown in FIG. 4B, but the reproduction time is longer than the relaxation oscillation time. Since it is long enough, the light emission in the relaxation oscillation state can be ignored.

For example, the reproduction time is on the order of 100 microseconds and the relaxation oscillation is on the order of 1-2 nanoseconds.

On the other hand, during recording, the signal a becomes low level as shown in FIG. 3B, and the signal c becomes high level as shown in FIG. 3C. Therefore, during reproduction, the B level setting circuit 48 operates and the A level setting circuit 46 does not operate. Here, the A level setting circuit 36 controls the LPF 4
Although the comparison between the output of 9 and the signal b is interrupted, the control signal of A level is held.

Then, during recording, the timing generation circuit 41 switches the switch 32, the switch 35, and the switch 37 to turn on sequentially in response to a control signal from the control circuit at the time when one channel clock is divided into three. A control signal is output to the switch 32, the switch 35, and the switch 37. That is, the timing generation circuit 41
At the first time when the one-channel clock is divided into three, the switch 32 is turned on to turn on the switch 35 and the switch 37.
In the second time when the 1-channel clock is divided into three, the switch 35 is turned on and the switch 32 is turned off.
And a control signal to the switch 32, the switch 35, and the switch 37 so that the switch 37 is turned on and the switch 32 and the switch 35 are turned off at the third time when one channel clock is divided into three so as to turn off the switch 37. Is output. The first time to the third time do not have to be equally divided, but the second time needs to be longer than the time when the first one cycle of relaxation oscillation ends.

During the first time of the 1-channel clock, a zero level control signal is input to the current drive circuit of the substrate 36 via the switch 32, the drive current becomes zero level, and the LD 35 does not emit light. That is, the recording medium 10
The recording film of No. 1 is cooled.

At the second time of the 1-channel clock, A
The A-level control signal held by the level setting circuit 36 is input to the current drive circuit of the substrate 36 via the switch 35, the drive current becomes the preliminary drive level, and the LD3
5 emits light at the preliminary light emission level. The preliminary drive level is
The level exceeds a threshold value that is the limit value of the drive current at which the LD 35 starts to emit light, and is a level at which the recording film of the recording medium 101 does not enter the recording state when the LD 35 emits light by the drive current at the preliminary drive level. In the present embodiment, the pre-driving level is matched with the reproduction driving level from the viewpoint of reducing the number of circuit components and reducing the circuit size and weight.

The LD 35 emits light by causing relaxation oscillation by the drive current of the preliminary drive level, but the preliminary light emission level is sufficiently smaller than the recording power level, so that the recording film does not enter the recording state.

At the third time of the 1-channel clock, P
A feedback loop including the D37, the LPF 49, the B level setting circuit 48, the switch 37, the substrate 36, the LD 35, the collimator lens 34, and the beam splitter 33 is formed. With this feedback loop, the B level setting circuit 48 generates a B level control signal using the signal d as a reference signal. This B-level control signal is input to the current drive circuit of the substrate 36, and the current drive circuit operates as shown in FIG.
As shown in A, a recording drive level current is generated. This recording drive level current is input to the LD 35, and the LD 35
Starts to emit light at the reproduction power level as shown in FIG. 5B. Here, the current of the recording drive level is input to the LD 35 stepwise as shown in FIG. 5A. However, since the relaxation current is generated by the drive current of the preliminary drive level, L
As shown in FIG. 5B, D35 does not cause relaxation oscillation in light emission at the recording power level.

Therefore, the recording film of the recording medium 101 is
Since the temperature is raised at an appropriately controlled recording power level,
Recording marks are formed within a predetermined range. Therefore, the recording / reproducing apparatus 10 can suppress cross write and jitter, and can perform stable recording.

In the pulse drive magnetic field modulation overwrite method, as shown in FIG. 5, since the duty of the recording pulse is constant with respect to the channel clock, only the recording pulses are collected and averaged, and all the light emission is performed. The same value can be obtained by monitoring the levels (zero level, preliminary light emission level and recording power level) and multiplying the duty.

Even in the case of continuous recording, as shown in FIG. 3, since the sector address is reproduced in order to specify the recording area, the preliminary drive level (reproduction drive level) is adjusted.

[0066]

As described above, in the recording / reproducing apparatus according to the present invention, before the laser is emitted at the recording power level,
Preliminary light emission is performed at a level that exceeds the light emission threshold and does not affect the recording film, so that relaxation oscillation does not occur during light emission at the recording power level. Therefore, the recording / reproducing apparatus according to the present invention can control the formation of recording marks. Therefore, the recording / reproducing apparatus according to the present invention can suppress cross write and jitter, and can perform stable recording.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a recording / reproducing apparatus.

FIG. 2 is a diagram showing a configuration of an optical pickup and a laser drive circuit.

FIG. 3 is a diagram showing a control timing chart of each level setting circuit.

FIG. 4 is a diagram showing a laser drive current and a laser emission waveform during reproduction.

FIG. 5 is a diagram showing a laser drive current and a laser emission waveform during recording.

FIG. 6 is a diagram showing a relationship between a recording speed and a laser emission waveform in a pulse drive magnetic field modulation overwrite system.

[Explanation of symbols]

18 Optical pickup 19 Laser drive control circuit 35 Semiconductor laser 36 board 37 Light receiving element 41 Timing generation circuit 42, 45, 47 switch 43 Control circuit 46 A level setting circuit 48 B level setting circuit 49 low-pass filter

Claims (4)

[Claims] 1. A magneto-optical recording / reproducing apparatus of a pulse drive magnetic modulation overwrite system, comprising: a laser for emitting a laser beam; a drive means for supplying a drive current to the laser; a zero level for not emitting the laser; A first level for emitting the laser with an emission intensity that does not make the direction of the magnetic field in the recording film changeable by the applied magnetic field, and light emission making the direction of the magnetic field in the recording film changeable by the applied magnetic field A control unit for controlling the drive current by outputting a control signal to the drive unit in order during a 1-channel clock at the time of recording data to a second level for emitting the laser with high intensity. Magneto-optical recording / reproducing device. 2. In a magneto-optical recording / reproducing apparatus of a pulse drive magnetic modulation overwrite system, a laser for emitting a laser beam, a driving means for supplying a drive current to the laser, and an emission intensity of the laser beam emitted by the laser. And a control means for controlling the drive current by outputting a control signal to the drive means, wherein the control means reproduces the data of the recording medium while reproducing the data from the recording medium. The control signal is adjusted based on the output of the detection means so that the emission intensity is set to be equal to, and the adjusted control signal is retained after the reproduction is finished, and the laser is not emitted while the data is being recorded on the recording medium. The output of the detection means is controlled so that the control signal is a current, the held control signal, and the emission intensity for recording data on the recording medium. Magneto-optical recording and reproducing apparatus characterized by controlling the drive current control signal adjusted Zui by outputting to the drive unit in order during one channel clock. 3. The magneto-optical device according to claim 1, wherein the laser and the driving unit are mounted on an optical pickup, and the driving unit and the control unit of the optical pickup are connected by a cable. Recording / playback device. 4. The laser, the driving means and the detecting means are mounted on an optical pickup, and the driving means, the detecting means and the control means of the optical pickup are connected by a cable. The magneto-optical recording / reproducing apparatus according to claim 2.