JP2003317249A - Device and method for automatically controlling quantity of laser beam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To cope with a high transfer rate of an optical disk drive unit. <P>SOLUTION: A detecting signal of inputted laser beams is inputted to a ternary level detecting circuit 2 by a preamplifier 1, and ternary level signals corresponding to a peak power, erase power and cooling power of the laser beams are produced from the above detected signal. Then, the difference of this ternary level signal from the set value is obtained and the difference signal is inputted to a waveform generating circuit 8. In the waveform generating circuit 8, the adding/non-adding operations of the difference signal are executed in accordance with data for recording, and a laser control signal for data recording is produced and outputted to a laser driver. Also, when the data are erased, the laser control signal for data erase is produced in the waveform generating circuit 8 by using an output of the ternary level detecting circuit 2, but when the data are reproduced, the detected signal is inputted to the waveform generating circuit 8 through the route different from the ternary level detecting circuit 2 to produce the laser control signal for data reproduction. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser light amount automatic control device for an optical disk drive which records, reproduces, and erases various information on, for example, a phase change optical disk.

[0002]

2. Description of the Related Art In recent years, an optical disk drive apparatus using a phase change optical disk has been provided as a writable optical recording system. In recent years, in particular, a high transfer rate of such an optical disk drive has been drastically attracting attention, and its needs are increasing. However, when the transfer rate of the phase-change type optical disk drive device is increased, the channel clock becomes higher and the required pulse width of the laser light source is becoming shorter. For example, in the conventional case, this channel clock is about 70 MHz, and the required minimum pulse width of the laser light source is about several nanoseconds at most, so a peak hold circuit or sample hold circuit composed of a capacitor and a diode is used. If a circuit is used, the peak level can be detected sufficiently.

[0003]

However, at the high transfer rate required in the future, the minimum pulse width of the laser light source is assumed to be about several hundred picoseconds, and the peak level is detected by the method as described above. If you do, the error may be large. For example, when using a peak hold circuit consisting of a diode and a capacitor, if the capacity of the capacitor is increased, the original peak voltage will not be reached,
On the contrary, if the capacity is reduced, the holding performance is deteriorated.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a laser light amount automatic control device and method capable of coping with a high transfer rate of an optical disk drive. It is a thing.

[0005]

In order to achieve the above object, the present invention achieves the above object by automatically irradiating a writable optical disc with a laser beam to record, reproduce, and erase data. In the control device, a detection signal input means for inputting a detection signal corresponding to the reflected light of the laser light applied to the writable optical disc, and the peak power of the laser light and the erase from the detection signal input to the detection signal input means. A ternary level detecting means for generating a ternary level signal corresponding to power and cooling power, and a waveform for generating at least a laser control signal for data recording using the ternary level signal detected by the ternary level detecting means. And generating means.

Further, according to the present invention, in the laser light amount automatic control method of an optical disk driving device for recording, reproducing and erasing data by irradiating a writable optical disk with laser light, the writable optical disk is irradiated. A detection signal corresponding to the reflected light of the laser light is input, a three-value level signal corresponding to the peak power, erase power, and cooling power of the laser light is generated from the detection signal, and at least the three-value level signal is used. It is characterized in that a laser control signal for data recording is generated.

In the laser light amount automatic control apparatus of the present invention, a three-value level signal corresponding to the peak power, erase power, and cooling power of the laser light is generated from the detection signal of the laser light, and the laser is detected using this three-value level signal. Since the control signal is generated, it is possible to generate a laser control signal having an appropriate waveform with a simple circuit configuration without requiring a control signal from the outside.

Further, in the laser light amount automatic control method of the present invention, the peak power of the laser light from the detection signal of the laser light,
Since a ternary level signal corresponding to erase power and cooling power is generated and a laser control signal is generated using this ternary level signal, a simple circuit without the need for an external control signal. Depending on the configuration
It is possible to generate a laser control signal having an appropriate waveform.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a laser light amount automatic control apparatus and method according to the present invention will be described below. FIG. 1 is a block diagram showing a configuration example of a laser light amount automatic control device according to an embodiment of the present invention. Also, FIG.
3 is a timing chart showing an operation at the time of reproduction and recording of the laser light amount automatic control device shown in FIG. 1, and FIG. 3 is a timing chart showing an operation at the time of reproduction and erasing of the laser light amount automatic control device shown in FIG. FIG. 4 is a block diagram showing a configuration example of a ternary level detection circuit provided in the laser light amount automatic control device shown in FIG. 5 is a timing chart showing operation waveforms of the ternary level detection circuit shown in FIG. 4, FIG. 5 (A) shows operation waveforms when the duty ratio of the input signal is minimum, and FIG. ) Indicates an operation waveform when the duty ratio of the input signal is 50%.

As shown in FIG. 1, the laser light amount automatic control system of the present embodiment comprises a preamplifier 1 and a ternary level detection circuit 2.
And a plurality of (four in the illustrated example) subtraction circuits 3, 4, 5,
6 and a plurality (4 in the illustrated example) of high gain amplifiers 3A,
4A, 5A, 6A, a multiplexer 7, a waveform generation circuit 8, a status controller 9, a MECL buffer 10, and ECL logic gates 11 and 12. The preamplifier (detection signal input means) 1 inputs the detection signal S0 ′ output from the amplification section (PDAmp) of the photodiode (PD) which is a laser light source, and performs impedance conversion, and is a three-value level detection circuit. The (three-value level detecting means) 2 detects a three-value level signal of peak power (Write), erase power (Erase), and cooling power (Cooling) from the output signal S0 of the preamplifier 1.

The subtraction circuits (difference means) 3, 4, 5, 6 are
The output signals of the preamplifier 1 and the ternary level detection circuit 2 and the preset peak power setting value (Write se
t), erase power set value (Erase set), cooling power set value (Cooling set), read power set value (Read set) (S40, S41, S42, S4)
3), and the high gain amplifiers 3A to 6A amplify the differential outputs of the subtraction circuits 3 to 6 (S5).
0, S51, S52, S53). The multiplexer 7 is
The outputs (S52, S53) of the subtraction circuits 5A and 6A are selected based on the instruction (S55) from the status controller 9. Waveform generation circuit (waveform generation means) 8
Are subtraction circuits 3A, 4A, multiplexer 7, status controller 9, and ECL logic gates 11, 12.
Based on the input from the control signal (S
60) is waveform-shaped.

The status controller 9 uses LD Enable
Signal, Write Mode signal, Erase Mode signal (S5, S6,
Based on S7), various status signals are output to the multiplexer 7, the waveform generation circuit 8, the ECL logic gates 11 and 12, and the laser driver. MEC
The L buffer 10 waveform-shapes a pulse signal having a blunt edge into a pulse having a sharp edge by a transmission line and transmits the signal to the logic gate at the next stage. This MECL buffer 10
Are shown together as one in the figure, but actually 2
The system is prepared. The ECL logic gates 11 and 12 are
Status controller 9 and MECL buffer 10
Based on the signals (S44, S45, S46, S47) from the ON / OFF control signals S56, S5.
7 is output.

Next, such an operation will be described in the order of data reproduction, data recording, data erasing, and mode switching control. (A) Operation during data reproduction The data reproduction operation is as shown in the timing chart of FIG. 2 or 3. First, a signal S obtained by photoelectrically converting laser light in a photodetector (PD) not shown
0'is impedance converted by the preamplifier 1,
It is input to the subtraction circuit 6, a difference signal between the voltage and the read power setting voltage (S4) is generated, and this signal is amplified by the amplifier 6A. The output (S53) of the amplifier 6A is input to the waveform generation circuit 8 via the multiplexer 7.

At this time, since the output of the multiplexer 7 selects the signal S53 in the data read mode (Read mode), S54 becomes S53. Further, in the waveform generation circuit 8, since S56 and S57 are in the off state, S50
And S51 are not added, and S53 is output as it is (S
60). The signal S60 thus obtained is transmitted to the laser diode drive circuit (LDD). That is, this data reproducing operation is performed using the feedback circuit of the system (reproduction processing system) which is separated from the system of recording and erasing (recording processing system) by the ternary level detection circuit 2.

(B) Operation during data recording The data recording operation is as shown in the timing chart of FIG. First, a signal S0 ′ obtained by photoelectrically converting laser light in a photodetector (PD) (not shown) is impedance-converted by the preamplifier 1 and then input to the ternary level detection circuit 2. The three-value level detection circuit 2 detects three levels (S30, S31 or S32, S33) of Write, Erase, and Cooling power.
Here, the signal S30 is input to the subtraction circuit 3, and a difference signal S40 from the set value (S1) of the write power is generated,
The difference signal S40 is amplified by the amplifier 3A. And
The output S50 of the amplifier 3A is input to the waveform generation circuit 8. Similarly, the signal S31 (or S32) is input to the subtraction circuit 4, a difference signal S41 with respect to the set value (S2) of the Erase power is generated, and the difference signal S41 is amplified by the amplifier 4A. Then, the output S51 of this amplifier 4A
Is input to the waveform generation circuit 8.

Further, the signal S33 is input to the subtraction circuit 5, and the difference signal S4 from the setting value (S3) of the cooling power is set.
2 is generated, and the difference signal S42 is amplified by the amplifier 5A. This output (S52) is input to the waveform generation circuit 8 via the multiplexer 7. The output S54 of the multiplexer 7 selects the signal S52 in the data write mode (Write mode), and S54 becomes S52. And
The waveform generation circuit 8 performs addition / non-addition control of S50 and S51 with respect to S54 (S60). This addition / non-addition control is performed by the signals S50, S5 by the signals S56, S57.
1 is turned on / off, S50 is added only when S56 is on, and S51 is added only when S57 is on. The signal S60 thus obtained is transmitted to the laser diode drive circuit (LDD).

(C) Operation when erasing data The data erasing operation is as shown in the timing chart of FIG. First, a signal S0 ′ obtained by photoelectrically converting laser light in a photodetector (PD) (not shown) is impedance-converted by the preamplifier 1 and then input to the ternary level detection circuit 2. The ternary level detection circuit 2 detects three levels of Write, Erase, and Cooling power (S30, S31 or S32, S33). In the data erasing mode (Erase mode), the laser power has only one value (DC Since the light is emitted, all of the outputs of S30, S31 (or S32), and S33 have the same value. Signal S30 from ternary level detection circuit 2
Is input to the subtraction circuit 3, and the set value of the write power (S
A difference signal S40 from 1) is generated. This difference signal S
40 is amplified by the amplifier 3A. And this amplifier 3A
Output S50 is input to the waveform generation circuit 8.

Similarly, the signal S31 or S32 is input to the subtraction circuit 4, and a difference signal S41 from the set value (S2) of the Erase power is generated. This signal S41 is amplified by the amplifier 4A. Then, the output S5 of this amplifier 4A
1 is input to the waveform generation circuit 8. Similarly, the signal S
33 is input to the subtraction circuit 5, and a difference signal S42 from the set value (S3) of Cooling power is generated. The difference signal S42 is amplified by the amplifier 5A. This output S52 is input to the waveform generation circuit 8 via the multiplexer 7.
The output S54 of the multiplexer 7 becomes the signal S52 in the data write mode. On the other hand, S56 at the time of erasing data is always in the off state, and
57 is always on. Further, since the output of the multiplexer 7 outputs the same level as S52, the output signal S60 of the waveform generation circuit 8 is the signal S51 and the signal S5.
It becomes the sum signal of 2. And the signal S obtained by this
60 is transmitted to the laser diode drive circuit (LDD).

(D) Operation of mode switching control The status controller 9 controls the switching of each mode of turning on / off the laser (LD), data reading, writing, and erasing in this example. First, turn on / off LD
The enable signal (S5) turns on / off the laser diode drive circuit (LDD) and the waveform generation circuit 8.
Specifically, the power supply of the waveform generation circuit 8 and the power supply and signals of the laser diode drive circuit (LDD) are shut off. In addition, data read / write / erase mode switching is performed by the Write Mode signal S6 and Erase Mode signal S7.
It controls the logic gates 11 and 12.

That is, when reading data, Write Mo
The de signal S6 is off, the Erase Mode signal S7 is off, and the control signals S56 and S57 for the logic gates 11 and 12 are off. When writing data, the Write Mode signal S6 is in the ON state, the Erase Mode signal S7 is in the OFF state, the control signal S56 of the logic gate 11 becomes S44, and the logic gate 12
The control signal S57 of becomes S45. In addition, at the time of erasing data, the Write Mode signal S6 is in the ON state and the Erase
The Mode signal S7 is on, the control signal S56 of the logic gate 11 is off, and the control signal S57 of the logic gate 12 is on.

Next, the ternary level detection circuit 2 in this example
Will be described. This ternary level detection circuit 2 is shown in FIG.
, The buffer amplifier unit 21, the multistage delay circuit 2
2A, 22B, detectors 24A, 24B, pulse generator 2
6A, 26B and peak / bottom detection units 28A, 28B. The buffer amplifier unit 21 includes three preamplifiers 2
1A, 21B, and 21C, which receives the output signal S0 of the preamplifier 1 at the previous stage, and receives the multistage delay circuits 22A and 22B.
Output to. The multi-stage delay circuits 22A and 22B are formed by cascade-connecting delay elements 221 each having a delay time of td, and sequentially delay the input signal from the buffer amplifier section 21 to obtain delay amounts (td, 2td, 3td).
) Different types of delayed signals are generated.

The detectors 24A and 24B respectively include a plurality of amplifiers 241, diodes 242, and resistors R1 and R.
The detection unit 24A outputs the highest voltage signal among the output signal S0 from the preamplifier 1 and the delay signals S10, S11, S12, and S13 by the multistage delay circuit 22A. Part 24B
Is an output signal S0 from the preamplifier 1 and delay signals S10 ', S11', S1 from the multistage delay circuit 22B.
It outputs the highest voltage signal of 2'and S13 '. The multi-stage delay circuits 22A and 22B and the detectors 24A and 24B constitute pulse width expansion means,
The peak of the short pulse is made easy to detect, and the one-valued three-valued pulse is separated into the two-valued binary pulse.

The peak / bottom detector 28A includes an amplifier 261 and a diode 281 connected to its output terminal.
And 282, resistors R3 and R4 connected downstream thereof, and capacitors C1 and C2. From the pulse signal binarized by the detection unit 24A in the preceding paragraph, the peak ((Write) signal (S3
0) is erased by the bottom hold circuit.
Each signal (S31) is detected. Furthermore, peak /
The bottom detection unit 28B includes an amplifier 262, diodes 283 and 284 connected to the output terminal thereof, resistors R5 and R6 connected downstream thereof, and a capacitor C3.
And C4. The peak hold circuit detects the erase signal (S32) and the bottom hold circuit detects the cooling signal (S33) from the pulse signal binarized by the detection unit 24B. In addition, these peak / bottom detection units 28
A and 28B detect the maximum level and the minimum level of the binarized pulse signal generated by the detection units 24A and 24B,
It is a means for separating a binary signal level into voltage signals of two systems.

Next, the operation of the ternary level detecting circuit 2 will be described. First, the waveform of the ternary level detection circuit 2 is premised on that the above-mentioned input signal S0 has a burst-like waveform such as S10 shown in FIG. The input signal S0 is output to the 2 via the buffer amplifier unit 21.
It is input to two multi-stage delay circuits 22A and 22B. The multi-stage delay circuits 22A and 22B are provided with nodes at every delay time td, and td, 2 from the input signals S10 and S10 '.
Signals S11, S11 'and S1 delayed by td and 3td
2 · S12 ′ and S13 · S13 ′ are generated. These signals S10 to S13 and S10 'to S13' are sent to the amplifier 24.
The signal is detected by the diode 242 via 1. And
The system of signals S10 to S13 detects the highest voltage among them, and the system of signals S10 'to S13' detects the lowest voltage among them. As a result, from the waveform having three levels as shown in FIG. 5, a binary pulse having amplitudes of the Write and Erase levels for the former and the Erase and Cooling levels for the latter is generated (S21, S22). .

When the signal S21 is input to both the peak hold circuit and the bottom hold circuit of the peak / bottom detector 28A, the output S30 of the peak hold circuit is output.
Is the write level and the output S31 of the bottom hold circuit.
Outputs Erase level respectively. On the other hand, when the signal S22 is similarly input to both the peak hold circuit and the bottom hold circuit of the peak / bottom detection unit 28B, the output S32 of the peak hold circuit is the Erase level and the output S33 of the bottom hold circuit is the Cooling level. Output.

In such a configuration, the multi-stage delay circuit 2
The delay time and the number of stages due to 2A and 22B are such that, when the shortest pulse width is Tmin and the pulse period is T, the delay time td per stage and the number of stages (necessary number of delay elements) N are td = Tmin (1 ) N = (T-Tmin) / Tmin (2) If the value calculated by the above equation (2) has a fractional part, the fractional part is rounded up.

As described above, in the laser light amount automatic control device according to the present embodiment, the ternary level detection circuit 2 as described above is employed, so that the laser light source of the laser light source can be controlled without using a control signal from the outside. The waveform required for control can be appropriately generated with a simple structure, and the timing of the control signal need not be taken into consideration. Further, since the ternary level detection circuit 2 adopts the method of lengthening only the pulse width without changing the peak value, the peak hold (or the bottom hold) can be performed remarkably easily.

By separating the feedback circuit from the laser photometer (PD) into a recording processing system including the ternary level detecting circuit 2 and a reproducing processing system not including the ternary level detecting circuit 2. It is possible to design the optimum loop characteristics during reproduction and during recording or erasing. Further, by mounting the waveform generating circuit 8, the semiconductor laser drive circuit can be simplified, and the heat generation amount can be reduced and the size can be reduced. Furthermore, since there is only one signal transmission line that connects the semiconductor laser drive circuit (laser driver; LDD) and the laser light amount automatic control device shown in FIG. 1, during this time, data due to differences in wiring length at high transfer rates There is no delay of pulse (Write, Erase). As a result, if the wiring length is controlled only inside the laser light amount automatic control device shown in FIG. 1, it is possible to easily increase the transfer rate.

Next, a modification of the present invention will be described. FIG. 6 is a block diagram showing a modified example of the laser light amount automatic control device shown in FIG. In addition to the configuration shown in FIG. 1, this automatic laser light amount control apparatus includes sample-hold circuits (S / H) 2A, 2B at the output stage of the ternary level detection circuit 2.
2C is inserted and high gain amplifiers 3A, 4A, 5
Sample and hold circuits (S / H) 3B and 4 are provided at the output stage of A.
B and 5B are inserted. Three-level level detection circuit 2
Output signal from S30, S31 or S32, S33
Are sample and hold circuits (S / H) 2A, 2
The samples are held by B and 2C, and the held values are output to the subtraction circuits 3, 4, and 5. Also, the output signals S50, S51, S5 of the high gain amplifiers 3A, 4A, 5A.
2 is a sample hold circuit (S / H) 3B,
The sample is held by 4B and 5B. And
The hold values of the sample hold circuits (S / H) 3B and 4B are input to the waveform generation circuit 8, and the hold values of the sample hold circuit (S / H) 5B are input to the multiplexer 7. Since the other points are the same as those in the example of FIG. 1 described above, description thereof will be omitted.

FIG. 7 is a block diagram showing a modification of the ternary level detection circuit shown in FIG. In the above example, the multistage delay circuits 22A and 22B in which the delay elements 221 having the same delay amount (td) are cascade-connected are used, but in the example shown in FIG. 7, three types of delay amounts (td, 2td) are used.
3td) of the delay elements 221A, 221B, 2
21C multi-stage delay circuits 22AA and 22B connected in parallel
B is used. Since the other points are the same as those in the example of FIG. 4 described above, description thereof will be omitted.

FIGS. 8 to 10 are timing charts showing three applicable waveform examples of the ternary level detecting circuit, where (A) is an input waveform to the ternary level detecting circuit, and (B) is a waveform chart. ) Indicates a pulse generation waveform, and (C) indicates an output waveform. Figure 8 shows the write pulse and erase (Era)
se) shows the case where the phases of the pulses are aligned and the duty ratio and amplitude are different. Further, FIG. 9 shows a case where the phases of the write pulse and the erase pulse are aligned, the duty ratios are the same, and only the amplitude is different. Further, FIG. 10 shows that the write pulse and the erase pulse are periodically repeated and only the amplitude changes, and the peak detection is performed in real time even when the peak power is changed and used. ing. The ternary level detection circuit according to the present embodiment can handle any of the input signals having these waveforms.

[0032]

As described above, according to the laser light amount automatic control apparatus of the present invention, a three-value level signal corresponding to the peak power, erase power, and cooling power of the laser light is generated from the detection signal of the laser light, Since the laser control signal is generated using this ternary level signal, a laser control signal having an appropriate waveform can be generated at high speed with a simple circuit configuration without requiring a control signal from the outside. It is possible to cope with high transfer rate.

Further, according to the laser light amount automatic control method of the present invention, a three-value level signal corresponding to the peak power, erase power, and cooling power of the laser light is generated from the detection signal of the laser light, and the three-value level signal is generated. Since the laser control signal is generated by using, it is possible to generate a laser control signal of an appropriate waveform at high speed with a simple circuit configuration without requiring a control signal from the outside. There is an effect that it can correspond to the transfer rate.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration example of a laser light amount automatic control device according to an embodiment of the present invention.

FIG. 2 is a timing chart showing operations during reproduction and recording of the laser light amount automatic control device shown in FIG.

FIG. 3 is a timing chart showing operations during reproduction and erasing of the laser light amount automatic control device shown in FIG.

4 is a block diagram showing a configuration example of a ternary level detection circuit provided in the laser light amount automatic control device shown in FIG.

5 is a timing chart showing operation waveforms in the ternary level detection circuit shown in FIG.

FIG. 6 is a block diagram showing a modification of the laser light amount automatic control device shown in FIG. 1.

7 is a block diagram showing a modification of the ternary level detection circuit shown in FIG.

FIG. 8 is a timing chart showing a first example of applicable waveforms of the ternary level detection circuit shown in FIGS. 4 and 7.

9 is a timing chart showing a second example of applicable waveforms of the ternary level detection circuit shown in FIGS. 4 and 7. FIG.

FIG. 10 is a timing chart showing a third example of applicable waveforms of the ternary level detection circuit shown in FIGS. 4 and 7.

[Explanation of symbols]

1 ... Preamplifier, 2 ... Tri-level detection circuit, 3,
4, 5, 6 ... Subtraction circuit, 3A, 4A, 5A, 6A ...
High gain amplifier, 7 ... Multiplexer, 8 ... Waveform generation circuit, 9 ... Status controller, 10 ... MEC
L buffer, 11, 12 ... ECL logic gate.

Continued front page    F term (reference) 5D090 AA01 BB04 CC01 CC04 FF21                       KK03                 5D119 AA10 AA24 BA01 BB04 HA16                       HA45 HA54 HA62                 5D789 AA10 AA24 BA01 BB04 HA16                       HA45 HA54 HA62

Claims (17)

[Claims] 1. A laser light amount automatic control device of an optical disk drive device for recording, reproducing and erasing data by irradiating a writable optical disk with laser light, wherein the writable optical disk is irradiated with laser light. Detection signal input means for inputting a detection signal corresponding to the reflected light, and a ternary level signal corresponding to the peak power, erase power, and cooling power of the laser light is generated from the detection signal input to the detection signal input means. A laser light amount automatic device comprising: a three-value level detecting means; and a waveform generating means for generating at least a laser control signal for data recording using the three-value level signal detected by the three-value level detecting means. Control device. 2. The laser light amount automatic control device according to claim 1, wherein the writable optical disk is a phase change optical disk. 3. A reproduction processing system different from the recording processing system including the three-value level detecting means is provided as a feedback circuit for the detection signal inputting means, and the reproduction processing system is based on each of the recording, reproducing and erasing mode designating signals. 2. The laser light amount automatic control device according to claim 1, further comprising state control means for controlling the waveform generating means and selecting processing of the recording processing system and the reproduction processing system. 4. A difference means for calculating a difference between a ternary level signal detected by the ternary level detecting means and a ternary level set value set for the peak power, erase power and cooling power. 2. The laser light amount automatic apparatus according to claim 1, wherein the waveform generating means generates a laser control signal for recording data and a laser control signal for erasing data using the difference signal obtained by the difference means. Control device. 5. A laser for data recording, comprising data input means for inputting recording data, wherein said waveform generating means performs addition / non-addition processing of said ternary level signal using said recording data. The laser light amount automatic control device according to claim 4, wherein a control signal is generated. 6. A laser control signal for data reproduction is generated by inputting a detection signal from the detection signal input means to the waveform generation means without passing through the three-value level detection means. 3. The laser light amount automatic control device described in 3. 7. A difference means for calculating a difference between a detection signal from said detection signal input means and a read level set value set for read power, said waveform generating means being obtained by said difference means. 7. The laser light amount automatic control device according to claim 6, wherein a laser control signal for data reproduction is generated using the differential signal. 8. The laser light amount according to claim 1, wherein the ternary level detection means has a peak detection circuit including a pulse width expansion means for expanding the pulse width while maintaining the peak value of the input pulse. Automatic control device. 9. The pulse width expansion means has a multistage delay circuit configured by cascade-connecting a plurality of delay elements having the same delay time, and a plurality of delays output from nodes of each delay element of the multistage delay circuit. 9. The laser light amount automatic control device according to claim 8, which outputs a maximum level or a minimum level of a signal. 10. The pulse width extending means has a multistage delay circuit configured by connecting a plurality of delay elements having different delay times in parallel, and a plurality of delay signals output from each delay element of the multistage delay circuit. 9. The laser light amount automatic control device according to claim 8, wherein the maximum level or the minimum level is output. 11. The ternary level detecting means includes a plurality of the pulse width expanding means, and a peak power is used as a process for separating a ternary level signal corresponding to the peak power, erase power and cooling power of the laser light. A binary pulse signal having a level corresponding to the erase power,
9. The laser light amount automatic control device according to claim 8, further comprising pulse generation means for generating a binary pulse signal having a level corresponding to the erase power and the cooling power. 12. The ternary level detecting means includes means for detecting a maximum level and a minimum level of the binary pulse signal generated by the pulse generating means, and separating the binary level pulse signal into a multilevel signal level. The automatic laser light amount control device according to claim 11. 13. A method for automatically controlling a laser light amount of an optical disk drive device, which records, reproduces, and erases data by irradiating a writable optical disk with laser light, wherein the laser light is irradiated onto the writable optical disk. Inputting a detection signal corresponding to the reflected light of the laser beam, generating a ternary level signal corresponding to the peak power, erase power, and cooling power of the laser beam from the detection signal, and using the ternary level signal for at least data recording. The laser light amount automatic control method is characterized in that: 14. The method for automatically controlling a laser light amount according to claim 13, wherein the writable optical disk is a phase change optical disk. 15. A laser control for data recording using a difference between the ternary level signal and a ternary level setting value set for the peak power, erase power and cooling power. 14. The laser light amount automatic control method according to claim 13, wherein a laser control signal for erasing a signal and data is generated. 16. The recording data is input, and the addition / non-addition processing of the ternary level signal is performed using the recording data to generate a laser control signal for data recording. 15. The automatic laser light amount control method according to item 15. 17. A difference between the detection signal and a read level set value set for the read power is calculated, and a laser control signal for data reproduction is generated using this difference signal. Item 14. A laser light amount automatic control method according to item 13.