JPS61224381A - Laser output control device - Google Patents

Abstract

PURPOSE:To enable the programmable and variable control of the laser output having the optimum peak value and pulse width for various objects to be CONSTITUTION:When the selection command signal for output switching of the laser composed of two reflection mirrors 1 and 2, a solid laser medium.

Description

DETAILED DESCRIPTION OF THE INVENTION 1.1 The present invention relates to a laser output control device, and more particularly to a pulse-excited solid-state laser output control device suitable for use in a laser processing machine or the like.

Since laser processing has the functional advantage of non-contact processing, it is suitable for improving processing quality and saving labor, and is put to practical use in all industrial fields.

Laser processing using pulse-excited solid-state lasers is often used in the fields of metal welding, drilling, cutting, and heat treatment because of its ability to concentrate and output high energy in a short period of time.

In pulse-pumped solid-state lasers, a waveform shaping circuit (hereinafter referred to as PF
Laser output can be obtained by discharging the electric charge charged in a flash lamp (abbreviated as "N") to a flash lamp serving as an excitation source.

In the conventional device, this laser output is used by uniquely setting the charging voltage and the discharging time of the PFN in advance. However, laser processing requires a laser output having a combination of peak value and pulse width that matches the material, shape, and dimensions of the workpiece.

Therefore, the present invention was made in view of such requirements, and its purpose is to externally command a laser output having the optimum wave height/value and pulse width for various workpieces. An object of the present invention is to provide a laser output control device that can be programmably and variably controlled.

Ordinary! 11. The laser output control device according to the present invention is directed to an output control device for a pulse-excited solid-state laser whose excitation source is a flash lamp inserted in the path of a discharge current from a charging circuit,
Its feature is that it has a charging control means that can freely change the charging voltage of the charging circuit according to an external command, and a discharging control means that can freely change the discharging period of the charging circuit according to an external command.

Tomokodan Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a circuit diagram of an embodiment of the present invention. Reference numerals 1 and 2 are two reflecting mirrors constituting a laser resonator.

3 is a solid laser medium, and 4 is a shutter, and when the shutter is closed, the laser output cannot be extracted to the outside even if the flash lamp 5 is turned on. 5 was an excitation light source. This is the Fludge 1 lamp. 6 is P
FN (waveform shaping circuit), 7 is a commutation circuit for turning off 5CR1 during discharge of the flash lamp 5, 8
is a shutter drive circuit.

9 is a controller, 5CRI and 2 gate G1
The pulse width of the laser output is selected by externally setting the delay time of the gate signal of PFN6 and G2.
It has a function to select the peak value of the laser output by setting the charging voltage externally. Also, when switching the charging voltage of PFN 6 externally, the P
It also has a function of automatically discharging the charged charge of the FN to the flash lamp 5 completely.

5CR2 works together with the commutation circuit 7 to turn off 5CR1, and when a gate signal is applied to its gate G2, it turns on and turns off 5CR1.

Here, when the flash lamp 5, which is the excitation source, is discharged from the PFN 6, a laser output that is almost similar to the magnitude and time waveform of the discharge current is obtained from the laser 3, so the magnitude and time width of the discharge current of the flash lamp are Through control, laser output with arbitrary peak value and pulse width can be obtained. In this case, the peak value of the laser output can be varied by controlling the charging voltage of the PFN 6, and the pulse width can be varied by cutting off the discharge current of the flash lamp at an arbitrary time.

Therefore, when a selection command signal for laser output switching is input to the controller 9, as shown in the waveform (a> in the time chart of FIG. A shutter drive signal as shown in b) is generated, and the shutter 4 in the laser resonator is activated by the shutter drive circuit 8.

After that, the gate signal of gate G1 of 5CR1 becomes (C
), 5CRI turns on, and PF
The charged Ti charge at N6 is discharged through the flash lamp 5. After a predetermined time T1 or T2, the gate signal of the gate G2 of 5CR2 is generated as shown in (d), 5CR2 is turned on, 5CR1 is turned off, and the discharge is stopped.

In other words, the charge stored in PFN6 is discharged by the flash lamp due to the signal (C), and the discharge current is cut off by the signal (d), so that T1 and T1 are respectively A and B with a pulse width of T2
of laser output can be obtained. The peak values of the laser outputs A and 8 are determined by the charging voltage of the PFN 6, respectively.

Laser output waveform C1 indicated by the dotted line in Fig. 2(e)
and 02 are obtained when the shutter is automatically closed when switching the selection from one laser output to the other, and the charge stored in the PFN 6 is completely discharged to the flash lamp 5 during that time. However, during this time, since the shutter 4 is closed, it is not taken out to the outside. This is why it is shown as a dotted line. Both C1 and C2 are automatically obtained when switching the laser output selection.

As shown in Figure 2, when the selection signal in (a) is low level, the laser output has a higher peak value and a shorter pulse width, and when the selection signal is high level, the laser output has a lower peak value and a shorter pulse width. If a long laser output is set in advance by the controller 9 in accordance with an external command, two sets of laser outputs having a certain peak value and a certain pulse width can be automatically extracted based on the high and low logic of the signal (a).

That is, by setting the charging voltage and pulse width (T1 or T2) of the PFN 6 in the controller 9 shown in FIG. Only two sets of laser outputs can be automatically extracted. Therefore, the optimal laser processing for two types of workpieces can be automatically selected, and the processing quality of laser processing can be improved and the labor saving of the production line can be achieved.

For simplicity, the above explanation is based on a laser processing machine that selects two sets of laser outputs, but by expanding this system, it is possible to arbitrarily select laser outputs with three or more sets of peak values and pulse widths, and production A flexible laser processing machine suitable for production lines can be realized.

In addition, in the explanation of Figure 2, the charge stored in the PFN is completely released to the flash lamp every time the laser output selection is switched, but in a system where the charge is completely released only when a lower peak value is selected. This is desirable in terms of extending the life of the flash lamp.

Furthermore, P which should obtain a lower peak value than the next selected
If 5CR1 of FIG. 1 is turned off when the charging voltage of FN is reached, the life of the flash lamp can be further extended because the charge of PFN does not need to be completely discharged to the flash lamp.

As described above, according to the present invention, by utilizing the feature of PFN as a large current supply source, a laser output having an arbitrary pulse width from a low peak value to a sufficiently high peak value can be electrically generated. We can provide the optimal laser processing machine system for all types of laser processing.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an embodiment of the present invention, and FIG. 2 is a time chart explaining the operation of the circuit shown in FIG. 4. Brief explanation of drawings Explanation of symbols of main parts

Claims (1)

[Claims] An output control device for a pulse-excited solid-state laser whose excitation source is a flash lamp inserted in a path of a discharge current from a charging circuit, the charging control means being able to freely vary the charging voltage of the charging circuit by an external command; 1. A laser output control device comprising: discharge control means that can freely vary the discharge period of a charging circuit according to an external command.