JPH0799362A - Laser output control device - Google Patents

Abstract

PURPOSE:To definitely control the control device for a 'long time by a method wherein the control device comparing the output signals from the first and second detection sensors is provided while amplifiers fluctuating the amplification factor of one signal out of the output signal from the first detector sensor or specific laser output command signal at the command of the control device are also provided. CONSTITUTION:The output signals from the first detection sensor 8 and the second detection sensor 16 are transmitted to a control device 13 during the operation time of the second detection sensor 16 to be compared and stored. Next, the stored amplification factor command signals are transmitted to amplifiers 17, 18. Besides, the output signal and the laser output command signal from the first detection sensor 8 are transmitted respectively to the amplifiers 17 and 18 to be compared with each other by a comparator 12. Next, the deviation signal is amplified by the other amplifier 14 to control the voltage and output current of a power supply 2. Through these procedures, the laser output can be almost definitely controlled for a long time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser output controller for a gas laser oscillator mainly used for sheet metal working.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIG. FIG. 2 is a schematic configuration diagram showing a laser output control device of a laser oscillator. The vacuum container 1 is filled with the laser medium gas, and the power source 2 supplies the electrodes 3A. A high voltage is applied between 3B to generate discharge 4. The laser medium gas excited by the discharge 4 emits a laser beam, and the emitted laser beam is amplified by the partial reflection mirror 5 and the total reflection mirror 6 having a slight transmittance, and the laser oscillation is generated from the partial reflection mirror 5. Output to the outside of the device. On the other hand, the first detection sensor 8 is irradiated with a minute detection beam 7 of several W to several tens W output from the total reflection mirror 6 having a slight transmittance. The output signal from the first detection sensor 8 is amplified by the amplifier 9 at a predetermined amplification rate, and the signal is compared with the laser output command signal 10 amplified by the amplifier 11 at a predetermined amplification rate by the comparator 12. Then, the deviation signal is amplified by the amplifier 14 to control the output voltage or the output current of the power supply 2 to control the output of the laser beam 15 to be constant.

[0003]

The amplification factors of the amplifiers 9 and 11 of the above-mentioned conventional laser output control device are P2 = K · P1 where P1 is the output of the detection beam 7 and P2 is the output of the laser beam 15. That is, it was obtained on the assumption that there is a fixed proportional relationship. Therefore, it is effective for monitoring the output fluctuation in a short time, but when the laser oscillation device is used for a long time and the reflecting mirrors 5, 6 are deteriorated,
Since the proportional coefficient K changes, there is a problem that the set laser beam output and the actual laser beam output differ. The present invention has been made under the circumstances described above, and an object of the present invention is to provide a laser output control device capable of controlling the laser output substantially constant over a long period of time.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a laser output control device for a laser oscillation device which amplifies a laser beam between a partial reflecting mirror and a total reflecting mirror having a small transmittance. The first object of the present invention is to provide a first detection sensor for detecting a weak detection beam that has passed through the total reflection mirror, and a second detection sensor that can be put in and taken out on the optical path of the laser beam that has passed through the partial reflection mirror. A detection sensor, a control device that compares the output signal from the first detection sensor and the output signal from the second detection sensor,
This is achieved by including an amplifier capable of changing the amplification factor of at least one of the output signal from the first detection sensor or a predetermined laser output command signal in response to a command from the control device.

[0005]

In the present invention, the second detection sensor for directly detecting the laser output is provided on the optical path of the output laser beam so that it can be taken in and out, and the output signals from the first detection sensor and the second detection sensor are compared. By obtaining the proportional coefficient K, the amplification factor of at least one of the amplifiers for amplifying the output signal of the first detection sensor or the laser output command signal is changed, so that the laser output is controlled to be substantially constant for a long period of time. can do.

[0006]

FIG. 1 is a diagram showing an embodiment of a laser output control device of the present invention, in which 16 is a second detection sensor which is provided so as to be able to be taken in and out, 17 and 18 are amplifiers whose gains can be changed, and 13 Is a control device for comparing and calculating the output signal of the first detection sensor 8 and the output signal of the second detection sensor 16,
Other reference numerals are the same as those in FIG. Next, the operation of this embodiment will be described with reference to FIG. Second detection sensor 1
At the time of the operation of 6, the output signal V1 of the first detection sensor 8 and the output signal V2 of the second detection sensor 16 are sent to the control device 13, converted into a proportional coefficient K = (V2 / V1) and stored,
The amplification factor Q = X × K is multiplied by a coefficient X determined for each of the amplifiers 17 and 18, and the amplifier 1 is used as an amplification factor command signal.
Send to 7,18. Output signal V from the first detection sensor 8
1 and the laser output command signal 10 are supplied to the amplifier 17,
It is sent to 18 and amplified by the amplification factor Q, and then compared by the comparator 12. Then, the deviation signal is amplified by the amplifier 14 and the output voltage or output current of the power supply 2 is controlled, so that the laser output is controlled to be substantially constant for a long period of time. Although the laser output control device according to the present invention does not always operate, output fluctuations in a short time are dealt with by the same control as the conventional laser output control device, and the long-term output fluctuations due to deterioration of the reflecting mirrors 5 and 6 are caused. Since the output fluctuation progresses very slowly,
For example, when the amount of change in the proportionality coefficient exceeds a specified value, the laser output can be controlled to be substantially constant even if it is operated intermittently. Also, of the amplifiers 17 and 18,
Even if the amplification factor of one of the amplifiers is fixed, the output control similar to that of the above embodiment can be performed by appropriately selecting the coefficient X.

[0007]

As described above, according to the laser output control device of the present invention, at least one of the output signal amplification factor of the first detection sensor and the laser output command signal amplification factor is changed. The laser output can be controlled to be substantially constant over the period, and the processing accuracy can be improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a laser output control device of the present invention.

FIG. 2 is a schematic configuration diagram showing a conventional laser output control device.

[Explanation of reference numerals] 1 vacuum container 2 power supply 3A, 3B electrode 4 discharge 5 partial reflection mirror 6 total reflection mirror 7 detection beam 8 first detection sensor 9, 11, 14, 17, 18 amplifier 10 output command signal 12 comparator 13 Control device 15 Laser beam 16 Second detection sensor

Claims (1)

[Claims] 1. A laser output control device of a laser oscillation device, wherein a laser beam is amplified between a facing partial reflection mirror and a total reflection mirror having a slight transmittance, and a weak laser beam transmitted through the total reflection mirror is used. A first detection sensor for detecting the detection beam, a second detection sensor provided so as to be able to be taken in and out on the optical path of the laser beam transmitted through the partial reflection mirror, an output signal from the first detection sensor and the second A control device that compares output signals from the detection sensor, and an amplifier that changes the amplification factor of at least one of the output signal from the first detection sensor or a predetermined laser output command signal according to a command from the control device A laser output control device characterized by the above.