JPS6047482A - Laser irradiating device - Google Patents

Abstract

PURPOSE:To enable to always recognize accurately the irradiating position to the processing point of invisible laser beams by a method wherein visible laser beams are made to pass through the hole of an output coupling mirror and the visible laser beams are made to concentrically superpose on the invisible laser beams. CONSTITUTION:An output coupling mirror 13 is provided in the interior of a first oscillator 10, which outputs CO2 laser beams. The mirror 13 has a hole 14 in the central part thereof, makes infrared laser beams L1 convert into annular beams there and makes the annular beams output from the hole 14, while visible laser beams L2, which are made to output from a second laser oscillator 16, pass through the hole 14 and are superposed, for example concentrically, on the beams L1. The superposed beams L1 and L2 are reflected by a reflector 17 for adjustment, are furthermore reflected by a reflector 18 for transmission and are projected to a matter 20 to be processed. A plural number of transmitting holes 21 have been provided by boring with the reflector 18. The beams L2, which passed through the holes 21, are detected by optical detectors 23a and 23b and if the beams L2 get off from the irradiating point having been set as an object of the beams L2, an output signal is obtained from a differential amplifier 24. By this signal, the reflection angle of the reflector 17 is adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a laser irradiation device, and more particularly to a device for recognizing the irradiation position of invisible light output from a gas laser oscillator such as CO1.

[Technical background of the invention and its problems]

In recent years, high-output CO laser oscillators with several kilowatts or more have been developed, and laser beams that emit powerful energy are used to process metals, inorganic materials, and various other materials.

The laser beam is usually transmitted to the processing point by a transmission optical system that combines a plurality of reflecting mirrors. By the way, since the above laser beam is invisible infrared light, it is necessary to recognize the irradiation position at the processing point, so visible light output from a laser oscillator such as He-He is superimposed on the above laser beam and transmitted. The light is introduced into an optical system. As shown in Fig. 1, the above device includes a high output CO and a laser oscillator (2) on the reflecting surface of a reflecting mirror (1) with a through hole (1a) formed in the center, which is tilted at an angle of 45 degrees. While the invisible laser beam (Ll) from the laser oscillator (3) is incident, the visible laser beam (L2) from the laser oscillator (3) is output toward the through hole (1a) and reflected by the reflecting mirror fl). The optical path of the invisible laser beam (Ll) is usually superimposed coaxially, and the two superimposed laser beams are then directed to the workpiece (6) using a total reflection mirror (4) and a condensing lens (5).
A configuration in which the information is transmitted to the processing point is known. However, with this device, the optical axes of the two laser beams will shift if the holding angle of the superimposing mirror (1) is incorrect.
There was a drawback that the irradiation position of the invisible laser beam at the processing point could not be accurately recognized, and the installation of the visible light laser oscillator (3) that had the role of position recognition became meaningless.

[Purpose of the invention]

An object of the present invention is to provide a laser irradiation device that always accurately recognizes the irradiation position of an invisible laser beam at a processing point.

[Summary of the invention]

A visible laser beam is passed through the hole of the output coupling mirror, which is a component of the unstable resonator, and coaxially superimposed on the invisible laser beam outputted from the output coupling mirror in an annular shape. It is designed to lead to the processing point.

[Embodiments of the invention]

The present invention will be explained based on drawings showing embodiments thereof. In FIG. 2, θ0 is, for example, a first laser oscillator that outputs a high-output C02 laser beam, and inside it is a convex mirror u9 that forms an unstable resonator. concave mirror (
1, an output coupling mirror +13 is provided. The output coupling mirror is an annular mirror having a hole 04 in the center, and outputs an invisible laser beam (Ll), which is infrared light, to the outside through an output window 4 as an annular beam. ae is a visible laser beam (L2) outputted by a second laser oscillator that outputs a visible laser beam (L2) that is visible light, and the visible laser beam (L2) passes through the hole of the output coupling hole 9-(13) and becomes an invisible laser beam ( L + ), for example, so as to coaxially overlap. The above two superimposed laser beams (Lx).

(L2) is reflected by the adjustment reflecting mirror a7), further reflected by the transmission reflecting mirror α barrel, and is irradiated onto the workpiece 4 through the condenser lenses U.

In the above configuration, the invisible laser beam (Ll) and the visible laser beam (Ll) are superimposed before being reflected by the adjusting reflector (17), so even if the angle of the adjusting reflector is changed, the two laser beams (Ls),
(IQ) is maintained in a coaxial state.

By the way, as shown in Figs. 3 and 4, four transmitting mirrors are placed on the transmission reflector a8 at positions pH on the circumference where an intensity that is approximately half of the central intensity of the visible laser beam (L,) can be obtained. Holes 01 are drilled every 90 degrees, and the visible laser beams (L,) that have passed through these transmission holes Qυ are detected by photodetectors (23a) to (23d) each equipped with an infrared light cut filter. , by amplifying in the lateral direction with the corresponding differential amplifiers (24a) and (24b), to obtain an output signal when the superimposed beams (Ll) and (Lt) are deviated from the target irradiation point. be able to. Using this output signal, the adjusting drive device (2!iil) of the adjusting reflector (17) is operated to maintain the coaxiality of the two superimposed laser beams (Ll) and (Lt) at all times. In other words, by detecting the transmitted light from the four transmission holes, the deviation of the optical axis of the second laser beam (L2) during its progress can be detected. , displacements in directions orthogonal to each other, for example, vertical and horizontal directions, can be detected and the adjusting reflector (17) can be kept at the correct angle.As shown in Fig. 5, each has two transmission holes. (25), (2[i)
Two transmission reflectors a? ), and the center of the transmission holes CJ5) and (26) are installed so that one direction of each center intersects orthogonally, so that the function can be made equivalent to that of the transmission reflector (18).

〔Effect of the invention〕

The laser beam for processing and the visible laser beam that recognizes the irradiation position of this beam are coaxially superimposed before entering the transmission optical system, and the configuration is configured so that the irradiation position can be constantly confirmed even during processing. By automatically correcting the deviation of the laser beam, appropriate processing is now possible.

In addition, the effective use of energy has been further improved, and the danger to the human body due to misaligned beams has been prevented.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing a conventional example, Fig. 2 is a schematic diagram showing an embodiment of the present invention, Fig. 3 is a detailed diagram of the visible laser beam detection part, and Fig. 4 is a detailed diagram of the transmission reflector. , FIG. 5 is a perspective view showing another embodiment of the present invention. αe...First laser oscillator (131...Output coupling mirror (LD...Invisible laser beam (16)
...Second laser oscillator (Lll)...Visible laser beam a7)...Reflector for adjustment (Lll)...Reflector for transmission eυ...Transmission hole agent Patent attorney Kensuke Norichika (and others) 1 person) Figure 1 Figure 2 Figure 3 Jie Figure 4 β 5121

Claims (4)

[Claims] (1) A first laser oscillator that has an unstable resonator and outputs infrared light, and a first laser oscillator that outputs visible light and passes this visible light through the hole of the output coupling mirror that is a component of the unstable resonator. A second light source is provided at a position where the infrared light is superimposed on the infrared light.
a laser oscillator, an adjusting reflector that reflects the superimposed infrared light and visible light, and a plurality of transmission mirrors that transmit the infrared light and visible light reflected by the adjusting reflector to the irradiated area. Laser irradiation characterized by comprising a reflecting mirror, a plurality of transmission holes formed in at least one of these transmission reflection mirrors, and a photodetector that detects the intensity of visible light passing through these transmission holes. Device. (2) The laser irradiation device according to claim 1, wherein the photodetector is used to control the adjustment of the reflection angle of the adjustment reflecting mirror based on the detected value. (3) The laser irradiation device according to claim 1, wherein the photodetector includes a filter that blocks infrared light. (4) The laser irradiation device according to claim 1, wherein the transmission holes are provided axially symmetrically.