JPH0411315B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laser beam output control device in a laser processing device.

[Conventional technology]

FIG. 3 is a configuration diagram showing a conventional laser output control device, in which a container 1 is filled with a laser medium gas 2,
The output voltage of the power source 4 causes a discharge between the electrodes 3A and 3B to excite the laser medium gas 2, and the total reflection mirror 5
Laser oscillation is generated between the partially transmitting mirror 6 and the partially transmitting mirror 6, and a laser beam 7 is output from the partially transmitting mirror 6.

This laser beam 7 is transmitted to bend mirrors 8A, 8B, 8
The light is transmitted to an arbitrary position by C, and is focused by a lens 10 attached to the processing head 9, and the workpiece 11 is processed near the focal position. In this case, a partially transmitting mirror 12 is inserted in the optical path of the laser beam 7, and the laser beam 7 is
A part of it is taken out and made incident on the integrating sphere 13. The inner surface of this integrating sphere 13 is made of a reflective material, and the beam becomes uniform by repeating reflections inside, so the laser light detector 14 detects a portion of the laser light 7 that has been uniformly attenuated. is compared with the output signal of the laser output setting device 15, and the deviation is determined by the amplifier 1.
6 and sends the signal to the power source 4, and feedback control is performed to keep the intensity of the laser beam 7 constant.

[Problem that the invention seeks to solve]

Since the conventional laser output control device is configured as described above, the reflected light 17 from the partially transmitting mirror 12 enters the integrating sphere 13 and is repeatedly reflected inside, as shown in FIG. 19 if the entrance 18 is large
Laser detector 1
4 cannot measure accurate laser intensity. Further, even if the laser beam 17 is attenuated when the bend mirrors 8A, 8B, and 8C after the monitor become dirty, there is a problem that the attenuation of the laser beam 7 in the optical path after the partially transmitting mirror 12 cannot be detected.

This invention was made in order to solve the above-mentioned problems, and it is an object of the present invention to obtain a laser output control device that can perform processing with accurate laser output without light leakage from the inlet of the integrating sphere. With the goal.

[Means for solving problems]

The laser output control device according to the present invention transmits light using a bend mirror, in which the bend mirror is a partially transmitting mirror, and the light intake port of the integrating sphere is brought into close contact with the transmitting side of the bend mirror, so that the laser beam can be transmitted. The intensity is detected and compared with the output of the laser output setting device, and the deviation signal is fed back to control the laser output.

[Effect]

In this invention, the light intake port of the integrating sphere is closely attached to the transmission side of the bend mirror closest to the processing lens, so there is no leakage of laser light from the integrating sphere intake port, and the laser power used for processing is reduced. accurately detect and control.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, numerals 1 to 6 are the same or corresponding parts as those with the same symbols in FIG. It is becoming more transparent.

FIG. 2 is an enlarged view of the detection section, and 20 is a partial reflection mirror, which is attached so that the light intake port of the integrating sphere 13 is in close contact with the transmission side. 21 is reflected light within the integrating sphere 13, 22 is an incident laser beam, and 23 is a total reflection coating.

Next, the operation will be explained. In Figure 2,
Most of the incident laser beam 22 is reflected by the total reflection coating 23 of the partially transmitting mirror 20, but only 1 to 2%.
Transparent. The transmitted laser beam hits the inner surface of the integrating sphere 13, and since the inner surface is made of a reflective material such as gold, it is repeatedly reflected. In addition, the part of the partially transmitting mirror 20 becomes the light inlet of the integrating sphere 13, but the reflected light 21
The light that tries to leak outside like this is partially transmitted by the partially transmitting mirror 2.
Since it is reflected by the total reflection coating 23 of 0, it does not leak to the outside. Therefore, the intensity of the laser light hitting the inner surface of the integrating sphere 13 is averaged, and a portion of the uniform laser light can be accurately detected by the laser light detector.

The accurately detected laser output signal is used to amplify the deviation from the signal from the laser output setting device 15 using an amplifier 16 and feed it back to the power source 4, thereby changing the discharge intensity between the electrodes 3A and 3B and changing the excitation intensity. The laser oscillation intensity can be controlled by If the laser oscillation efficiency decreases,
Even if the bend mirrors 8A and 8B are dirty, the laser intensity at the detection section is controlled to be constant, so the excitation output of the power source 4 can be increased to always provide accurate laser power at the detection section. , it has become possible to perform stable laser processing.

In the above embodiment, the detection mechanism using an integrating sphere is provided on the bend mirror closest to the lens, but other bend mirrors may be used and the same effects as in the above embodiment can be achieved.

〔Effect of the invention〕

As described above, according to the present invention, since the integrating sphere is closely attached to the bend mirror and the laser power is detected to control the laser output, the laser light does not leak from the integrating sphere inlet, and the laser There is no effect on fluctuations in oscillation efficiency, and stable laser processing can be performed.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an integrating sphere laser output control device according to an embodiment of the present invention, FIG. 2 is an enlarged view of the detection portion in FIG. 1, and FIG. 3 is a block diagram of a conventional laser output control device. FIG. 4 is an enlarged view of the detection portion in FIG. 3. In the figure, 2 is a laser medium gas, 5 is a total reflection mirror, 6 is a partial transmission mirror, 7 is a laser beam, 8A, 8B
is a bend mirror, 10 is a lens, 13 is an integrating sphere,
20 is a partially transmitting mirror. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A laser processing device that transmits a laser beam output from a laser oscillator to an arbitrary position using a bend mirror, focuses it on a processing lens, and performs laser processing near the focal position, wherein the bend mirror is partially 1. A laser output control device comprising a transmitting mirror, and a light inlet of an integrating sphere that outputs a laser beam to be compared with the output of a laser output setting device is closely attached to the transmitting side of the bend mirror.