JPH0738479B2 - Cross-flow carbon dioxide laser device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lateral flow type carbon dioxide gas laser device, and more particularly to a method for starting discharge.

[0002]

2. Description of the Related Art Conventionally, a cross-flow type carbon dioxide laser device is shown in FIG.
Also, as shown in FIG. 2, a laser wind tunnel 1 in which a predetermined gas is sealed is formed in a substantially annular shape. A discharge unit 2 is provided in the upper part of the laser wind tunnel 1, and a blower 3 is provided in the lower part. In the discharge part 2, one common electrode 4 and a plurality of divided electrodes 5 are arranged so as to face each other, and stabilizing resistors are connected in series to the divided electrodes 5, respectively. The common electrode 4 is connected to the + side of the high voltage power supply 7, and the stabilizing resistor 6 is connected to the − side.

In such a cross-flow carbon dioxide laser device, the discharge is started by setting the pressure of the enclosed gas to the initial value, then causing the discharge, and gradually increasing the discharge current to bring the current level of the discharge to the desired value. . Alternatively, after that, the discharge current is immediately increased to a desired value.

[0004]

When the discharge gas is started after the charged gas pressure is set to a desired value as in the conventional case at the time of starting the discharge, the inter-electrode voltage at the start of the discharge is high and The gas temperature of the part is also cold, and the voltage between the electrodes is getting higher and higher. That is, the discharge is difficult to start. If discharge occurs in this state, there is a high possibility that problems such as arc discharge or abnormal discharge to other metal than between the electrodes occur. Furthermore, when the discharge current is raised to a desired value at the same time as the start of discharge, arc discharge and abnormal discharge are more likely to occur. An object of the present invention is to provide a lateral flow carbon dioxide gas laser device capable of eliminating an unstable state at the time of starting discharge and allowing stable start of discharge.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a cross-flow carbon dioxide gas laser device in which a discharge part is provided in a laser wind tunnel in which a gas containing helium is sealed, and the gas is caused to flow in the discharge part to cause discharge. At the time of starting the discharge, the ratio of helium in the gas mixture ratio is increased to cause a low current level discharge, and then the mixture ratio is gradually set to a predetermined value over a certain period of time, and the discharge current level is gradually increased. The cross-flow carbon dioxide gas laser device is provided with a control unit that raises the discharge current level to a desired value when the mixing ratio reaches the predetermined value.

[0006]

Therefore, according to the present invention, by taking the above means, the control means increases the proportion of helium in the gas mixture ratio to cause a low current level discharge when the discharge is started, and thereafter, The mixing ratio is gradually set to a predetermined value over a certain period of time, the discharge current level is also gradually raised, and the discharge current level is set to a desired value when the mixing ratio reaches the predetermined value. It is possible to eliminate the unstable state and start stable discharge.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to solve the above problems, the structure of the lateral flow carbon dioxide gas laser device of the present invention is almost the same as that of FIGS. 1 and 2, but a control unit for controlling the mixed gas mixture ratio and the discharge current. (Not shown).

That is, at the time of starting the discharge, the control unit increases the gas mixing ratio of He that easily causes the discharge (however, the filled gas pressure is raised to a desired value in advance) to cause the discharge at a low current level. . This discharge may be a so-called symmer discharge (preliminary discharge) such as a pulse laser, or may be a main discharge. Since this discharge has a high mixing ratio of helium, it has a lower inter-electrode voltage than the expected discharge, and is a so-called discharge that is easy to light up. . After that, the control unit gradually changes the mixing ratio to a normal value over a certain period of time, and also gradually increases the discharge current level, and when the gas mixing ratio becomes almost a normal value, the discharge current level is set to a desired value. Value.

[0009]

As described above, according to the present invention, it is possible to cause a discharge in a state in which it is easier to start than in the past, and it is possible to perform a so-called soft start of discharge. As a result,
The conventional problems have been resolved.

[Brief description of drawings]

FIG. 1 is a schematic front view showing a cross-flow type carbon dioxide gas laser device which has been conventionally used.

FIG. 2 is a circuit configuration diagram of a main part of a conventionally used lateral flow carbon dioxide gas laser device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Laser wind tunnel, 2 ... Discharge part, 3 ... Blower, 4 ... Common electrode, 5 ... Divided electrode, 6 ... Stabilization resistance, 7 ... High voltage power supply.

Claims (1)

[Claims] 1. A cross-flow carbon dioxide laser device in which a discharge part is provided in a laser wind tunnel in which a gas containing helium is sealed, and the gas is caused to flow through the discharge part to generate a discharge. Increasing the proportion of helium in the mixing ratio to cause discharge at a low current level, and then gradually setting the mixing ratio to a predetermined value over a certain period of time,
A cross-flow carbon dioxide laser device comprising a control means for gradually increasing the discharge current level and for setting the discharge current level to a desired value when the mixing ratio reaches the predetermined value.