JPH06216444A - Laser oscillator - Google Patents

Abstract

PURPOSE:To make automatic adjustment of the optical axis in a laser oscillator. CONSTITUTION:Four through-holes 14 are provided on a circle whose center is the center of a laser beam 8 directed to a light receiving part 11 having the function of an external shutter, and a temperature sensor 15 to receive a beam passing through the through-holes 14 is provided. Each mirror is so adjusted that the temperature of the temperature sensor 15 becomes uniform.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser oscillator mainly used in the field of sheet metal cutting.

[0002]

2. Description of the Related Art To improve the stability of a laser oscillator,
Both the laser output and the transverse beam mode must be controlled to be constant. As shown in FIG. 4, the NC device 3 controls the laser output in the oscillating state by the total reflection mirror 1 having a slight transmittance.
While monitoring the signal from the output detection sensor 2 arranged at the rear of the discharge current, the discharge current flowing from the high-voltage power supply 5 to the discharge electrode 6 is controlled by controlling the discharge current so as to reach a preset output. . The control of the beam transverse mode is performed by the operator adjusting the optical axis by manually operating the angle adjusting knob 4 of each mirror constituting the resonator. That is, the laser beam 8 transmitted through the partial reflecting mirror 7 may be adjusted so as to be in the transverse mode having the beam intensity as shown in FIG.

[0003]

The above-described conventional laser oscillator has a problem that the beam transverse mode cannot be controlled when the optical axis is displaced due to vibration or stress applied to the laser optical system. The present invention has been made under the circumstances described above, and an object of the present invention is to provide a laser oscillation device capable of automatically adjusting the deviation of the optical axis.

[0004]

The present invention relates to a laser oscillating device for oscillating a laser beam in an excited laser medium, and the above object of the present invention is to shield an emitted laser beam arbitrarily. An optical axis adjusting device having a light receiving section for receiving a laser beam passing through at least three or more through holes formed concentrically from the center of the laser beam with a temperature sensor is provided. This is achieved by adjusting the optical axis of the laser optical system.

[0005]

In the present invention, focusing on the fact that the beam transverse modes of the laser beam have almost the same beam intensity on the concentric circle, a means for measuring the beam intensity at each point on the concentric circle of the laser beam is provided. Since it is installed in the light receiving portion having the function of the external shutter, the deviation of the optical axis can be automatically adjusted.

[0006]

1 is a diagram showing an example of an optical axis adjusting device provided in a laser oscillator according to the present invention. FIG. 1A is a plan view, FIG. 1B is a side view, and FIG. (C) is a rear view of the main part. The light receiving unit 11 is a rotary solenoid 1
It is provided so as to be swingable by 2 and has a function of an external shutter. In the state of the light receiving unit 11 indicated by the chain double-dashed line in FIG. 7A, that is, in the state where the external shutter is open, the laser beam 8 is output toward the processing machine not shown, and the light receiving unit 11 is in the solid line in FIG. In this state, that is, when the external shutter is closed, the laser beam 8 is emitted from the light receiving unit
To be shielded by. At this time, the light receiving unit 11 is cooled by cooling water (not shown) passing through the inside. The light receiving unit 11 is provided with four through holes 14 concentrically from the center of the irradiated laser beam 8. When the temperature sensor 15 is irradiated with the laser beam that has passed through the through hole 14, the output signal from the temperature sensor 15 is sent to the NC device.

FIG. 2 is a perspective view showing an example of a mirror angle adjusting device provided in the laser oscillator of the present invention. The mirror mounting plate 22 to which the total reflection mirror 1 or the partial reflection mirror 7 is attached is provided with one fixed fulcrum 23, two movable fulcrums 24 with a built-in motor, and a pressing spring 25. By doing so, the angle of the total reflection mirror 1 or the partial reflection mirror 7 can be freely changed. FIG. 3 is a schematic view of the entire laser oscillator of the present invention. The NC device 31 monitors the temperature difference between the four temperature sensors 15 with the external shutter closed. When the temperature difference exceeds the predetermined set range, the mirror mounting plate 22 is set so that the temperature difference returns to the set range while monitoring the signal from the output detection sensor 2 so as not to drop suddenly. The movable fulcrum 24 is operated to adjust the angle of the total reflection mirror 1 or the partial reflection mirror 7. As a result, a laser beam having a constant beam transverse mode can be output. In the above-described embodiment, the through holes 14 provided in the light receiving portion 11 are provided at four concentric circles, but the number is not limited to this. For example, the through holes 14 may be provided at three concentric circles or four.
Even if the number and the position are different, for example, by providing two diagonal positions on different concentric circles, the same effect as above can be obtained. Although the optical axis adjustment is automated by providing the mirror angle adjusting device, the optical axis adjustment can be performed by manually adjusting the mirror angle.

[0008]

As described above, according to the laser oscillator of the present invention, the deviation of the optical axis can be automatically adjusted.
The number of man-hours and costs required for maintenance can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of an optical axis adjusting device provided in a laser oscillator of the present invention.

FIG. 2 is a perspective view showing an example of a mirror angle adjusting device provided in the laser oscillating device of the present invention.

FIG. 3 is a schematic view of the entire laser oscillator of the present invention.

FIG. 4 is a schematic view of an entire conventional laser oscillation device.

FIG. 5 is a diagram showing a beam transverse mode of a general laser beam.

[Explanation of symbols]

 1 Total Reflector 2 Output Detection Sensor 3,31 NC Device 4 Manual Mirror Angle Adjustment Knob 5 High Voltage Power Supply 6 Discharge Electrode 7 Partial Reflector 8 Laser Beam 11 Light Receiver 12 Rotary Solenoid 14 Through Hole 15 Temperature Sensor 22 Mirror Mounting Plate 23 Fixed Fulcrum 24 movable fulcrum 25 spring

Claims (1)

[Claims] 1. A laser oscillating device for oscillating a laser beam in an excited laser medium, wherein at least three emitted laser beams are shielded in a concentric circle from the center of the laser beam. A laser characterized by comprising an optical axis adjusting device having a light receiving section for receiving a laser beam passing through the above through hole with a temperature sensor, and adjusting the optical axis of the laser optical system by the output of the temperature sensor. Oscillator.