JPH0466114B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a gas laser device having a plurality of discharge paths that is effective in ensuring discharge and non-discharge and stabilizing discharge for processing and medical purposes.

Structure of a conventional example and its problems A conventional gas laser oscillation device of this type is shown in FIGS. 1 and 2. FIG. 1 shows a configuration diagram of a conventional laser device with a plurality of laser tubes, and FIG. 2 shows a configuration diagram of a conventional laser device with a single laser tube.

As shown in FIG. 2, the output end of the high voltage DC power supply 1 is connected to the cathode 6 through the anode 3 and resistor 4 of the laser tube 2, and the cathode 6 is grounded through the resistor 5 and fixed to the cathode 6 of the laser tube 2. A current control circuit 7 was connected. The constant current control circuit 7 includes, for example, a high voltage vacuum tube 8, a current adjustment transistor 9, base and emitter current adjustment signal circuits 10A and 10B, and a constant voltage element 11. It was connected between the base and collector of the adjustment transistor 9.

In such a conventional constant current control circuit 7, the high voltage of the high voltage DC power supply 1 is shared between the resistor 4 and the resistor 5 before the start of discharge for laser oscillation in the discharge path. Since a low voltage is applied and the discharge voltage is not reached, no discharge occurs. However, when a signal is input from the base current adjustment signal circuit 10A to the base of the current adjustment transistor 9 and the current adjustment transistor 9 is turned on,
The cathode potential of the high-voltage vacuum tube 8 decreases, and the anode potential decreases due to an apparent increase in the lattice potential, resulting in a high voltage between the anode 3 and cathode 6 of the laser tube 2, which applies a discharge voltage to the laser tube 2 and starts discharging. be done. At this time, the constant voltage element 11 connected between the base and collector of the current adjustment transistor 9 is within the rated value of the constant voltage element due to the anode current of the high voltage vacuum tube 8 and the impedance between the collector and ground of the current adjustment transistor 9. The voltage becomes constant, and the anode potential is controlled by adjusting the lattice voltage of the high-voltage vacuum tube 8. However, if there are multiple discharge paths connected in parallel to the high-voltage DC power supply 1, the voltage will be constant due to variations in each element. This has the disadvantage that a difference occurs in the lattice voltage of each discharge path, which causes a difference in the discharge state of each discharge path, and that some discharge paths have incomplete discharge. In particular, when performing pulse oscillation, if the difference between the high voltage power supply 1 and the discharge starting voltage is small, the discharge will be incomplete and the pulse oscillation cannot be performed reliably. In addition, since the constant voltage element 11 is connected to the base side of the current adjustment transistor 9, leakage current to the constant voltage element 11 is prevented from flowing through the current adjustment transistor 9.
This caused noise to the base signal of the oscillator, and caused disturbances in discharge and uncertainty in pulse oscillation, especially during pulse oscillation.

OBJECT OF THE INVENTION The present invention provides a gas laser device which eliminates the above-mentioned drawbacks and also ensures flashing of discharge when discharging a plurality of discharge paths, and in particular stabilizes discharge during pulse oscillation to ensure laser oscillation. With the goal.

Structure of the Invention The gas laser device of the present invention is provided with a high-voltage DC power supply that supplies a discharge current, at least one discharge path is connected to the high-voltage DC power supply, and a constant current control circuit is provided on the cathode side of each discharge path. The constant current control circuit is connected to the cathode of a high-voltage vacuum tube for pulse generation that supplies a pulse signal to the discharge path, and the collector of a discharge current control transistor is connected to the base of the transistor, and the current adjustment signal circuit is connected to the base of the transistor. A constant voltage element and a voltage supply power source for supplying power to the constant voltage element are connected to the collector of the transistor.

The present invention reliably regulates and adjusts the anode voltage of the high voltage vacuum tube before the start of discharge with the above configuration, and
In particular, there is no effect on the base signal entering the transistor during pulse oscillation, making it possible to stabilize the discharge and ensure laser oscillation.

Description of examples The present invention will be explained based on the drawings.

FIG. 3 shows a circuit diagram of a discharge circuit including a constant current control circuit in an embodiment of the present invention.

In FIG. 3, the same reference numerals as in FIG. 2 represent the same parts, and 12 represents a voltage supply power source to the constant voltage element 11.

As shown in FIG. 3, in the embodiment of the present invention, a constant voltage element 11 is connected between the cathode of the high voltage vacuum tube 8 of the conventional constant current adjustment circuit 7 and the collector of the current adjustment transistor 9, and a voltage is supplied thereto. The configuration is such that a voltage supply power source 12 is connected, and one end thereof is grounded.

Therefore, a constant voltage is supplied from the voltage supply power supply 12 to the constant voltage element 11, and the lattice potential of the high voltage vacuum tube 8 in the constant current control circuit 7 provided in each discharge path is set to the negative side by the constant voltage element 11. The anode potential is made large and configured to maintain a high anode potential before the start of discharge. Therefore, the no-load state before the start of discharge can be ensured. In particular, during pulse oscillation, discharge and non-discharge are repeated, so in addition to ensuring a no-load state, one end of the constant voltage element 11 is grounded, and the current adjustment signal circuit 10A of the current adjustment transistor 9 is By configuring a separate circuit, it is possible to separate the noise caused by the leakage current that enters from the current adjustment signal circuit 10A through the constant voltage element 11.

As explained above, the present invention provides a constant current control circuit that keeps the discharge current of a laser tube constant, in which a constant voltage element having a voltage supply power source is connected between a high voltage vacuum tube and the collector of a current adjustment transistor. Since one end is grounded, the discharge voltage is more stable than the conventional configuration in which a constant voltage element is connected between the base and collector of the current adjustment transistor, and the no-load condition is ensured. This makes it possible to reliably regulate and adjust the anode voltage of the high-voltage vacuum tube before the start of discharge, ensuring laser oscillation. In addition, the current adjustment signal circuit of the current adjustment transistor and the constant voltage element are configured as separate circuits, which separates noise caused by leakage current that enters the current adjustment signal circuit through the constant voltage element. can do. As a result, it is possible to eliminate the influence on the base signal entering the constant current adjustment transistor during pulse oscillation.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of a gas laser device including a conventional constant current control circuit, Fig. 2 is a configuration diagram of a conventional single laser tube laser device, and Fig. 3 is an embodiment of the present invention with constant current control. 1 shows a circuit diagram of a gas laser device including a circuit. 1... High voltage DC power supply, 2... Laser tube, 3...
Anode of laser tube 2, 4, 5...Resistor, 6...
Cathode of laser tube 2, 7...constant current control circuit,
8...High voltage vacuum tube, 9...Transistor for current adjustment, 10A, 10B...Signal circuit for current adjustment,
11... Constant voltage element, 12... Voltage supply power to the constant voltage element 11.

Claims (1)

[Claims] 1. A high voltage DC power supply that supplies a discharge current is provided, at least one discharge path is connected to the high voltage DC power supply, a constant current control circuit is provided on the cathode side of each discharge path, and the constant current control circuit is The collector of a discharge current control transistor is connected to the cathode of a high voltage vacuum tube for pulse generation that supplies pulse signals to the discharge path, a current adjustment signal circuit is connected to the base of the transistor, and a current adjustment signal circuit is connected to the collector of the transistor. A gas laser device characterized in that it is configured by connecting a voltage element and a voltage supply power source that supplies power to the constant voltage element.