JPH0444380A - gas laser device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a gas laser device such as a carbon dioxide laser, and more particularly to a laser device which aims to downsize a high voltage power supply, stabilize output power, and increase output power. .

BACKGROUND OF THE INVENTION In conventional gas laser devices, the gas laser medium is
The laser beam is supplied through a supply duct by an air blower into a laser resonator equipped with an output mirror and a total reflection mirror, and is excited by discharge from a discharge electrode to output laser light.

The high voltage for generating laser light is, for example, 200V.
A commercial power supply is rectified and smoothed to produce a low-voltage DC power supply, the output of which is intermittent by a semiconductor switch element to create a high-frequency AC voltage, which is boosted by a step-up transformer, rectified by a rectifier circuit, and smoothed by a smoothing capacitor. It is applied to the discharge electrode of the laser resonator. Such a power supply configuration has the advantage that the device can be miniaturized.

Problems to be Solved by the Invention In gas laser devices, it is necessary to generate a voltage of 30 to 50 kV in order to maintain the discharge of the gas laser medium, and this voltage needs to be further increased in order to achieve high output. There is. In addition, in the rectifier circuit for rectifying the boosted high-frequency voltage, the rectifier diodes are connected in a full bridge in order to reduce the current ripple after smoothing, but in order to increase the output, As the voltage is increased, the output voltage is at a higher frequency, which tends to cause dielectric breakdown between the output terminals, making the output of the high-voltage power supply unstable and resulting in poor reliability.

The present invention provides a gas laser device that can miniaturize the high-voltage power supply of the gas laser device by increasing the frequency of the DC voltage, and increase the output by increasing the voltage to increase the laser light output. The purpose is to

Means for Solving the Problems In order to achieve the above object, the present invention provides a high voltage power supply that
It is configured to include a low-voltage AC power supply that can change the effective voltage, a step-up transformer, and a rectifier circuit, and the rectifier circuit is connected in a full-bridge manner with two sets of rectifier diodes, and the intermediate connection point of each set is connected to the secondary of the step-up transformer. In addition to being connected to the output terminal of the coil, two sets of rectifier diodes are mounted on separate members and placed on both sides of the secondary coil of the step-up transformer inside the transformer container.

Effect of the present invention With the above configuration, the secondary coil output terminals of the step-up transformer are separated from each other on both sides of the secondary coil, and two sets of rectifier diodes connected in a full bridge are connected to the two separated output terminals. Therefore, dielectric breakdown between the rectifier diodes is less likely to occur, and as a result, dielectric breakdown of the rectifier diodes can be prevented and the output of the high voltage power supply can be increased.

EXAMPLES Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 3 shows a schematic configuration of a gas laser device in an embodiment of the present invention. In FIG. 3, 1 is a laser resonator, 2 is an output mirror, and 3 is a total reflection mirror. 4a, 4b
5 is a discharge electrode, 5 is a discharge part of the gas laser medium in the laser resonator l, 6 is a blower, 7 is a cooler, 8 is a supply air duct, 9
is the exhaust duct. In addition, 10 is a low voltage DC power supply, 1
Reference numeral 1 denotes an inverter circuit that serves as a low-voltage AC power source, and is composed of four full-bridge connected semiconductor switching elements. Reference numeral 12 denotes a step-up transformer having an insulated structure in which a primary coil and a secondary coil are coaxially wound, and an inverter circuit 11 is connected to the primary side of the step-up transformer. A rectifier circuit 13 is connected to the secondary side of the step-up transformer 12, and is composed of four full-bridge connected rectifier diodes 132 to 13d.

14 is a smoothing capacitor connected in parallel to the rectifier circuit 13, and both ends 14a and 14b of the smoothing capacitor 14 are connected to discharge electrodes 4a and 4b, respectively.

As shown in FIGS. 1 and 2, the step-up lance 12 includes a transformer coil 16 in which a ferrite core 15 and a primary/secondary coil are coaxially wound around one leg 15a.
The legs 15 are placed in a transformer container 18 filled with insulating oil 17.
It is fixed to a transformer mounting base 21 with its both sides sandwiched between a pair of core holders 19° and 20 made of an insulating material, with the axis a in the horizontal direction. A capacitor holder 22 is attached to the upper part of the ferrite core 15, passing between the core holders 19 and 20, and the smoothing capacitor 14 is fixed thereon. Furthermore, two sets of rectifier diodes 132 to 13d are mounted on the outer surface of each of the core holders 19 and 20.

One core holder 19 has a set of rectifier diodes 13.
a, 13b are attached and connected to each other at their intermediate connection point 23. This intermediate connection point 23 is connected to one end 12a of the secondary output terminal of the transformer coil 16, and the other ends 24 and 25 of the rectifier diodes 13a and 13b are connected to the positive and negative terminals 14a and 14b of the smoothing capacitor 14, respectively. There is. Similarly, in the rectifier diodes 13c and 13d installed on the other core holder 20,
The intermediate connection point 26 between the two is connected to the other end 12b of the secondary coil output terminal of the transformer coil 16, and the rectifier diode 1
The other ends 27 and 28 of 3c and 13d are smoothing capacitors 14
It is connected to the positive and negative terminals 14a and 14b of. The positive and negative terminals 14a and 14b of the smoothing capacitor 14 are connected to ceramic high-voltage insulators 30 and 31 provided on the top plate 29 of the transformer container 18, respectively, and the primary side of the transformer coil 16 is connected to the input terminal 32. has been done.

Next, the operation of the above embodiment will be explained. In FIG. 3, a gas laser medium is introduced into the laser resonator 1 by a blower 6.
is supplied through the air supply duct 8 to the discharge electrodes 4a,
The laser beam is excited by causing a glow discharge between the electrodes 4b and generates a laser beam. The generated laser light goes back and forth between the output mirror 2 and the total reflection mirror 3, is amplified, and finally reaches the output mirror 2.
taken out from the The gas laser medium whose temperature has increased in the laser resonator 1 is recovered through the exhaust duct 9,
The air is cooled by the cooler 7 and sent into the laser resonator 1 again by the blower 6 through the air supply duct 8.

The output of the low-voltage DC power supply 10 generates an AC voltage by alternately turning on and off the semiconductor switching elements of the inverter circuit 11, and changing the AC frequency depending on the period of the connection and connection.
The effective voltage is changed depending on the connection time. The alternating current boosted to high voltage by the step-up transformer 12 is passed through the rectifier circuit 13.
It is rectified by the rectifier diode 1" 132~13d,
It is smoothed by the smoothing capacitor 14 to become a high voltage direct current, which is applied to the discharge electrodes 4a and 4b in the laser resonator 1.

In FIGS. 1 and 2, among the AC voltages inside the transformer container 18, the secondary coil output terminals 122, 12b of the transformer coil 16 have the highest voltage. A rectifier diode 13 connected to the secondary coil output terminals 12a and 12b.
Since the coils 2 to 13'd are distributed one set each to both the left and right ends of the transformer coil 16, the high frequency output voltage from the secondary coil output terminals 12a and 12b can be isolated. As a result, when the output of the transformer coil 16 is increased, it is possible to prevent damage to the rectifier diodes 132 to 13d due to dielectric breakdown that occurs between the secondary coil terminals 12a and 12b. Step-up transformer 1 by increasing the output frequency of circuit 11
2 can be miniaturized, and a highly reliable high voltage power supply with large output can be obtained.

Effects of the Invention As described above, according to the gas laser device of the present invention, the rectifier circuit for rectifying high frequency voltage is connected by full bridge connection of two sets of rectifier diodes, and the intermediate connection point of each set is connected to two sets of rectifier diodes. In addition to connecting to the output terminal of the secondary coil, two sets of rectifiers are mounted on separate members and placed on both sides of the secondary coil of the step-up transformer inside the transformer container, making it possible to miniaturize the high voltage power supply and By increasing the voltage, the output can be increased and the laser light output can be increased.

[Brief Description of the Drawings] Fig. 1 is a schematic configuration diagram showing a step-up transformer according to an embodiment of the present invention, Fig. 2 is a partial side view showing a rectifier diode mounting part in the step-up transformer, and Fig. 3 is a schematic diagram showing the step-up transformer according to an embodiment of the present invention. 1 is a schematic configuration diagram of a gas laser device showing an example. Laser resonator, 2... output mirror, 3... total reflection mirror,
4a, 4b...Discharge electrode, 5...Discharge part of gas laser medium, 6...Blower, 7...Cooler, 8...Air supply duct, 9...Exhaust duct, 10. ...Low voltage DC power supply, 11...Inverter circuit (low voltage AC power supply),
12... Step-up transformer, 12a, 12b... Step-up transformer output terminal, 13... Rectifier circuit, 13a-13d...
... Rectifier guioto, 14 ... Smoothing capacitor, 14
a. 14b... Capacitor terminal, 15... Ferrite core, 16... Transformer coil, 17... Insulating oil, 1
8... Transformer container, 19.20... Core holder,
21...Transformer mounting base, 22...Capacitor holder, 23.26...Intermediate connection point, 24, 25, 27.
28...Other end of rectifier diode, 29...Top plate, 3
0゜31...High voltage insulator, 32...Input terminal. Name of agent Patent attorney Masahiro Kura Go Figure 3

Claims (1)

[Claims] In a gas laser device that generates laser light by exciting a gas laser medium in a laser resonator by discharging a discharge electrode connected to a high voltage power supply, the high voltage power supply is a low voltage AC power supply that can change the effective voltage. , a step-up transformer, and a rectifier circuit, the rectifier circuit has two sets of rectifier diodes connected in a full bridge manner, and an intermediate connection point of each set is connected to an output terminal of a secondary coil of the step-up transformer;
A gas laser device characterized in that a set of rectifying diodes is mounted on separate members and arranged on both sides of a secondary coil of a step-up transformer in a transformer container.