JPH1065242A - Gas laser oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stop a discharge, when a disturbance due to atmospheric leak is present by counting the time when a value, obtained by amplifying a laser light detection signal from a photodetector with a specified amplification factor, drops below a set ratio of a command output and stopping a DC high-voltage source, when the time thus counted exceeds a set time of a timer. SOLUTION: A command output is set by a signal P1 attenuator 11 at a set ratio. When an arc-like discharge takes place due to a disturbance, discharge excitation is hardly performed. Since a laser output light detection signal P2 is substantially Ow, a timer 13 performs counting, if the result of comparison with the set ratio from a comparator 12, i.e., a laser light detection signal P2 ×b, is lower than the set ratio of a command output signal P1 . If it exceeds a set time, a DC high-voltage source 2 is turned OFF to interrupt the discharge. More specifically, the DC high-voltage source 2 is turned off by detecting an unstable discharge due to atmospheric leak or the like, and the discharge is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas laser oscillating device for safe protection from abnormal discharge due to disturbance.

[0002]

2. Description of the Related Art A conventional gas laser device will be described with reference to FIG. In FIG. 3, 1 is a gas laser medium, 2 is a DC high-voltage power supply, 3a and 3b are discharge electrodes respectively connected to the DC high-voltage power supply 2, 4 is a partially transmitting reflection mirror for amplifying light and taking out laser light, Reference numeral 5 denotes a partially transmitting reflection mirror for extracting minute laser light incident on the photodetector 6, reference numeral 7 denotes a laser tube, reference numeral 8 denotes an amplifier for amplifying the laser light detection signal from the photodetector 6, and reference numeral 9 outputs a command output signal. Command output setting device,
Reference numeral 10 designates a laser output detection signal from the photodetector 6 as an amplifier 8
Is a control device that compares the amplified signal with the command output and feeds back the DC high-voltage power supply 2.

Next, the operation of the conventional gas laser oscillation device will be described. First, discharge is performed from the discharge electrodes 3a and 3b connected to the DC high-voltage power supply 2. As a result, the gas laser medium 1 is excited by obtaining discharge energy, and the excited gas laser medium is brought into a resonance state by the optical resonator formed by the partial transmission reflection mirrors 4 and 5, and the laser is transmitted from the partial transmission reflection type mirror 4. Light is output. This laser light is used for processing such as welding and cutting. Further, a minute laser beam is extracted by the partial transmission type mirror 5, detected by the photodetector 7, and the laser output signal is compared with the command output signal from the command output setting device by the control device to obtain a predetermined laser output. The power feedback control is performed as follows.

[0004]

In the gas laser oscillation device having the above-mentioned conventional configuration, the state of the laser medium changes due to disturbances such as atmospheric leak, connection of a laser gas cylinder, and mistakes, and the discharge state becomes unstable. There was a problem of maintaining a stable state.

An object of the present invention is to solve the above-mentioned conventional problems.

[0006]

In order to achieve this object, the present invention provides a photodetector for detecting the output of a laser beam, and a value obtained by amplifying a laser beam detection signal of the photodetector at a predetermined amplification factor. The timer includes a timer that counts the time when the value becomes equal to or less than the set ratio of the command output, and a control device that stops the DC high-voltage power supply when the time exceeds the timer set time.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS With the above configuration, the gas laser oscillation device of the present invention has a function of detecting when the state of the laser medium changes due to disturbance and making the discharge unstable, and stopping the discharge. . Hereinafter, embodiments of the present invention will be described with reference to FIG. 1 and FIG. In FIG.
Reference numerals 1 to 10 are the same as those in the related art, and a description thereof will be omitted.

Reference numeral 11 denotes an attenuator for attenuating the command output signal P1 from the command output setter 9 to a set ratio a. Reference numeral 12 denotes a command output signal (P1 × a) from the attenuator 11 and a laser beam detection signal P2. A comparator for comparing the laser light detection signal (P2 × b) amplified by the amplifier 8 with a predetermined amplification ratio b,
(A) P1 × a ≧ P2 × b or (B) P1 × a <P2
× b is output as one of the comparison output signals. A timer 13 counts a set time t (for example, 3 seconds) to prevent malfunction due to noise. When P1 × a ≧ P2 × b is longer than (c) the set time t, or (d) is shorter than the set time t. Is output. Reference numeral 14 denotes a device for controlling the DC high-voltage power supply 2 based on the comparison output signal (b) from the comparator 12 or the comparison output signals (c) and (d) from the timer 13. In the case of the control output signal (c), The DC high voltage power supply 2 is turned off, and the comparison output signal (b), (d)
In this case, the DC high-voltage power supply 2 is kept ON.

Next, the operation will be described with reference to FIG. First, the command output is set to a set ratio a (for example, 1/10) by the signal P1 (for example, 1 kW) attenuator 11. When the discharge becomes an arc due to disturbance, the discharge is hardly excited, and the laser output light detection signal P2 (for example, 20w) becomes about 0w. If the laser light detection signal P2 × b is 1/10 or more of the command output signal P1, the DC high voltage power supply 2
Is maintained in the ON state, and if less than 1/10, the timer 1
The counting is performed by 3, and when the set time t or more (for example, 3 seconds) or more is reached, the DC high-voltage power supply 2 is turned off to stop the discharge.

With the above operation, it is possible to detect that the discharge has become unstable due to air leakage or the like, and to turn off the DC high-voltage power supply 2 to stop the discharge.

[0011]

According to the present invention, there is provided a gas laser oscillating device, comprising: a photodetector for detecting an output of a laser beam; and a value obtained by amplifying a laser beam detection signal of the detector at a predetermined amplification ratio to a set ratio of a designated output. A timer that counts the time when the time has elapsed and a control device that stops the DC high-voltage power supply when the time exceeds the timer set time. Since the discharge can be stopped, an excellent effect of preventing damage to components of the gas laser oscillation device can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a gas laser oscillation device according to an embodiment of the present invention.

FIG. 2 is a flowchart according to the embodiment;

FIG. 3 is a schematic block diagram of a conventional gas laser oscillation device.

[Explanation of symbols]

 Reference Signs List 6 photodetector 8 amplifier 9 command output setter 11 attenuator 12 comparator 13 timer 14 controller

Claims (1)

[Claims] 1. A gas laser oscillating device which discharges and excites a gas laser medium with a high-voltage DC power supply to generate laser light in a continuous or pulsed manner, wherein the photodetector detects an output of the laser light, and the photodetector. A timer that counts the time when the value obtained by amplifying the laser light detection signal at a predetermined amplification rate falls below the set ratio of the command output signal, and stops the DC high-voltage power supply when the time exceeds the timer set time Gas oscillation device provided with a control device for performing the operation.