JPS6325989A - Gas laser - Google Patents

Abstract

PURPOSE:To generate discharge in a gas laser tube, whose starting voltage has become high due to operation for a long time, readily at a relatively low voltage, by winding a trigger coil in a spiral form around the outer surface of an outer container on the side of the cathode of the laser tube, and applying the same potential as that of an anode. CONSTITUTION:A piece of wire 7 for triggering is wound in a spiral form around the outer surface of an outer container 16 on the side of the cathode of a laser tube 1 and connected to an anode 3. When a power source is operated and a high voltage is applied between the cathode 2 and the anode 3 through a coaxial cord 5, the high voltage is simultaneously applied between the spiral shaped trigger coil 7 and the cathode 2. A gas in the tube between the trigger coil 7 and the cathode 2 is excited and ionized through the outer wall of the outer container. Since the high voltage applied between the spiral-shaped trigger coil 7 and the cathode 2 is applied to the outer wall of the outer container, main discharge is not generated in this section. Meanwhile, since the same high voltage is applied between the cathode 2 and the anode 3, the main discharge is immediately generated, and laser light 12 can be obtained.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to improvements in gas laser devices.

[Conventional technology and its problems]

A gas laser device generates a laser by filling a laser tube with a gas that serves as a laser medium, applying a high voltage between an anode and a cathode to generate a discharge, and appropriately adjusting the relative angular position of mirrors installed at both ends of the laser tube. Causes oscillation. However, in order to discharge a gas laser tube, some kind of trigger means is required in addition to the voltage for maintaining discharge. A commonly used method is to superimpose a triggering high voltage sufficient to start a discharge on the anode in addition to a discharge sustaining voltage to cause the gas laser tube to discharge. Converter-type power supplies have come into widespread use because they have many advantages, such as being easy to start because of their steep voltage rise speed, and being compact and easy to remove. By the way, when a gas laser tube is used for a long time, a phenomenon occurs in which the starting voltage increases and no discharge occurs. For this reason, the start voltage is designed with a margin of about 1.5 to 2 times the start voltage required for the initial state, but even then, a phenomenon occurs in which the start voltage becomes insufficient and no discharge occurs. It is possible to give the start voltage 3 or 4 times more margin than the initial state, but
The disadvantage was that the higher the voltage, the more difficult the insulation process, and the larger the entire power supply.

An object of the present invention is to provide a gas laser device that eliminates these drawbacks and is equipped with a means for easily causing discharge at a relatively low voltage in a gas laser tube whose starting voltage has increased due to long-term use. That's true.

[Means for solving problems]

The gas laser device of the present invention is characterized in that a trigger coil is spirally wound around the outer periphery of the cathode-side envelope of the laser tube and the same potential as that of the anode is applied.

In the gas laser device of the present invention, the same voltage as between the anode and cathode is applied between the cathode and the trigger coil spirally wound around the outer periphery of the cathode side envelope. Since the discharge distance in the tube between the spirally wound trigger coil and the cathode is shorter than that between the anode and the cathode, the gas in the tube between the spirally wound trigger coil and the cathode is ionized. starts at a lower voltage than the discharge between the anode and cathode.

However, the ionization of the gas in the tube between the trigger coil wound spirally around the outer circumference of the cathode side envelope and the cathode cannot become a main discharge because it is via the outer circumference of the cathode side envelope, that is, the insulator. This pre-ionizes the gas inside the tube to facilitate the main discharge between the anode and cathode. Therefore, when the high-voltage power supply is operated and a high voltage is applied between the anode and the cathode, the trigger coil wound around the outer circumference of the cathode-side envelope and the cathode are first passed through the outer wall of the cathode-side envelope into the tube. Gas pre-ionization begins,
At the same time, a discharge between the anode and cathode starts, which immediately becomes the main discharge.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a diagram showing one embodiment of the present invention. The laser tube is housed in a cylindrical case 8 and fixed by laser tube fixing screws 9 provided at eight locations on the cylindrical case 8. A high voltage is supplied to the laser tube 1 from a power source (not shown) via a coaxial cord 5.A positive potential is applied to the inner conductor of the coaxial cord 5 via a stabilizing resistor 13 to the anode 3 of the laser tube 1.
A negative potential is connected to the outer conductor of the coaxial cord 5 to the cathode 2 of the laser tube 1, and at the same time, the outer conductor of the coaxial cord 5 is connected to the cathode 2 of the laser tube 1.
It is connected to a ground terminal 4 provided in the section.

A front plate 10 provided with an output window 11 on the front side of the cylinder case 8
is attached to the rear surface of the cylindrical case 8, and a rear plate 15 is attached to the rear surface of the cylindrical case 8. A coaxial cord 5 is fixed to the rear plate 15 via a cord stopper 6. A trigger wire 7 is spirally wound around the outer periphery of the cathode side envelope 16 of the laser tube 1 and connected to the anode 3.

Operate the power supply and connect the Yin 8i via the coaxial cord 5! 2 and the anode 3, a high voltage is simultaneously applied between the spiral trigger coil 7 and the cathode 2, and the voltage between the trigger coil 7 and the cathode 2 is increased through the outer wall of the envelope. The gas inside the tube becomes excited and ionized. However, since the high voltage applied between the spiral trigger coil 7 and the cathode 2 passes through the outer wall of the envelope, a main discharge does not occur between the spiral trigger coil 7 and the cathode 2. Since this high voltage is applied, the main discharge immediately occurs and the laser beam 12 can be obtained.

In this example, in the conventional gas laser device, the starting voltage was approximately 5 to 6 KV at the initial stage, and the starting voltage increased to 1 KV after being used for a long time.
What used to require 8KV to 20KV can be stably and reliably discharged at IIKV to 12KV, which is approximately 40% lower, by wrapping the trigger coil 7 around the outer circumference of the cathode side envelope 16 and making it the same potential as the anode 3. It became so.

〔Effect of the invention〕

According to this invention, even in a laser tube whose starting voltage has increased after being used for a long time, it is possible to sufficiently discharge the laser tube even if the supply voltage from the power supply is low, which not only simplifies the insulation process but also This has the effect of keeping the shape small without increasing the number of parts needed to increase the starting voltage.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing one embodiment of the present invention. 1... Laser tube, 2... Cathode, 3... Anode, 7...
...Trigger coil, 8...Cylindrical case, 13...
stable resistance.

Claims (1)

[Claims] A gas laser device characterized in that a trigger wire is wound around the outer periphery of the cathode-side envelope of the laser tube to have the same potential as the anode.