JPH1146033A - Gas laser oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease variation rate of laser output for providing stable processing by applying high voltage under identical condition with processing in waiting, generating laser beam and absorbing the laser beam with an absorber so that the laser beam is not released to the outside. SOLUTION: A direct current high-voltage source 2 controlled by a control device 7 is discharged from discharging electrodes 3a and 3b by applying high voltage to the discharging electrodes 3a and 3b. Thus, a gas laser medium 1 is excited, which is filled in a laser tube 6 and resonated with an optical cavity comprising a partial transmission reflecting mirror 4 and a total reflection mirror 5, and a laser beam 11 is radiated from the partial transmission reflection mirror 4. An absorber 8 is in a closing position during waiting and in opening position at the processing start. While waiting, a high voltage which is identical to that at the processing start is applied to the discharging electrodes 3a and 3b by a processing start indication 12 input to a control device 10, and the laser beam 11 is not released to the outside during the waiting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas laser oscillator capable of generating a stable laser beam by reducing the fluctuation rate of a pulsed laser beam.

[0002]

2. Description of the Related Art FIG. 1 is a block diagram showing a configuration of a gas laser oscillation device to which the present invention is applied.

In FIG. 1, 1 is a gas laser medium, 2 is a DC high voltage power supply, 3a and 3b are discharge electrodes connected to the DC high voltage power supply 2 and 4 is a partially transmissive reflection light for amplifying light and extracting a laser beam 11. Mirror 5, a total reflection mirror for amplifying light, 6
Is a laser tube, 7 is a control device for controlling the DC high-voltage power supply 2, 8 is an absorber, 9 is a driving device of the absorber 8, 10
Is a control device of the driving device 9.

First, a DC high-voltage power supply 2 controlled by a control device 7 shown in FIG. 1 applies a high voltage to discharge electrodes 3a and 3b connected to the high-voltage power supply, so that the discharge electrodes 3
Discharged from a and 3b. As a result, the gas laser medium 1 filled in the laser tube 6 is excited by obtaining discharge energy, and the excited gas laser medium 1 is an optical resonator formed by the partial transmission type reflection mirror 4 and the total reflection mirror 5. , And the laser beam 11 is output from the partial transmission mirror 4. During the standby time when the processing is not performed, the absorber 8 is located in front of the partial transmission type reflecting mirror 4 so that the laser beam does not leak outside. In addition, the discharge of an arbitrary output is performed during the standby time when the processing is not performed.

FIGS. 6A and 6B show a machining start command 12 input to a conventional control device 10 and an external emission state of a laser beam 11. During processing standby (A), the absorber 8 is closed and the laser beam 11 is not emitted to the outside, but at the start of processing (B)
As a result, the absorber 8 is opened, and the laser beam 11 is emitted to the outside. This laser beam is used for processing such as drilling of a printed board (not shown).

[0006]

However, in the control by the conventional control device 10 described above, the discharge state during the machining standby and the discharge state during the actual machining are different, so that the dissociation state of both laser gases is different and the machining is started. From time to time, it takes time for the dissociation of the laser gas to stabilize, and the laser output fluctuates greatly and processing is unstable.
In addition, it takes time to stabilize the partial transmission type reflector and the total reflection mirror due to the thermal influence and to stabilize the electrode surface state.
There is a problem that the fluctuation of the laser output becomes large and the processing becomes unstable.

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

[0008]

To achieve this object, a gas laser oscillator according to the present invention comprises an absorber for receiving a laser beam, a driving device for driving the absorber, and a control device for controlling the driving device. A control device that, even during standby when laser processing is not performed, applies a high voltage under the same conditions as during processing, generates a laser beam, and controls absorption by an absorber so that the laser beam is not emitted to the outside Having.

With the above configuration, the gas laser oscillation device of the present invention has an operation of reducing the fluctuation rate of a pulsed laser beam and generating a stable laser beam.

[0010]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIG.

(Embodiment) FIG. 1 is a block diagram showing the configuration of a gas laser oscillation apparatus to which the present invention is applied, as described above. As shown in the machining operation of the oscillator, the discharge state during machining standby (A) is equivalent to the condition at the time of machining start (B).

That is, the operation of the absorber 8 is in the closed state during processing standby (A) and in the open state at the start of processing (B), as in the prior art. The same high voltage is applied during the processing standby (A) and at the start of processing (B) by the processing start command 12 input to the control device 10, and the laser beam 11 is in the processing standby
(A) is not emitted to the outside, but is emitted to the outside at the start of processing (B).

FIGS. 3, 4 and 5 show the fluctuation rate of the laser output under each condition. FIG. 3 shows the fluctuation rate (%) between the command output (horizontal axis) and the laser peak output (vertical axis). As a result, during processing (FIG. 2A) during processing standby (FIG. 2A).
It can be seen that when a high voltage is applied with the command output of (B)), the fluctuation rate of the laser peak output is reduced.

FIG. 4 shows the fluctuation rate (%) of the pulse ON time (horizontal axis) and the laser peak output (vertical axis). From this, it can be seen that the fluctuation rate of the laser peak output is reduced when a high voltage is applied during the processing ON (FIG. 2B) during the processing standby (FIG. 2A) during the pulse ON time.

FIG. 5 shows the fluctuation rate (%) of the pulse frequency (horizontal axis) and the laser peak output (vertical axis). Thus, it can be seen that the fluctuation rate of the laser peak output is reduced when a high voltage is applied at the pulse frequency during processing during the processing standby.

[0016]

As described above, the present invention comprises an absorber for receiving the laser beam, a driving device for driving the absorber, and a control device for controlling the driving device. Even during processing, the laser output fluctuation rate is reduced by applying a high voltage under the same conditions as during processing, generating a pulsed laser beam, and absorbing the laser beam with an absorber so as not to emit it to the outside. Thus, an excellent gas laser oscillation device capable of performing more stable processing can be realized.

[Brief description of the drawings]

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

FIG. 2 is a diagram illustrating a processing operation of the gas laser oscillation device according to the embodiment of the present invention.

FIG. 3 is a diagram showing a correlation between a command output and a fluctuation rate of a laser peak output in the embodiment of the present invention.

FIG. 4 is a diagram showing a correlation between a pulse ON time and a fluctuation rate of a laser peak output in the embodiment of the present invention.

FIG. 5 is a diagram showing a correlation between a pulse frequency and a fluctuation rate of a laser peak output in the embodiment of the present invention.

FIG. 6 is a diagram showing a processing operation of a conventional gas laser oscillation device.

[Explanation of symbols]

8 ... absorber, 9 ... drive device, 7,10 ... control device.

Claims (1)

[Claims] 1. A pulse-like high voltage is applied between electrodes provided at both ends of a discharge tube filled with a laser gas to generate a discharge in the discharge tube, and a total reflection mirror and a partial reflection mirror are provided at both ends of the discharge tube. Respectively, a gas laser oscillator that generates a laser beam in the axial direction of the discharge tube by optical amplification, an absorber that receives the laser beam, a driving device that drives the absorber, and a Equipped with a control device that performs control, even during standby when laser processing is not being performed, a high voltage under the same conditions as during processing is applied to generate a laser beam, and the laser beam is absorbed by the absorber so as not to emit it to the outside A gas laser oscillation device, comprising: a control device that performs control to perform the control.