JPS58154479A - Laser machining device - Google Patents

Abstract

PURPOSE:To make the focusing positions of an invisible laser beam and a visible one coincident, in a laser machining device wherein the latter beam is superposed on the former, by providing a divergent lens which diverges only the visible laser beam. CONSTITUTION:The visible laser beam 3 superposed around the axis 5 of an invisible laser (CO2 laser) beam 1 is reflected by a plane reflection mirror 11 and is conducted to a condenser lens 12 of which the axis is aligned to the axis 5. Since the laser 3 is diverged by the peripheral convex of a divergent lens 16, the focal position past the lens 12 can be made longer. The focal length of the lens 16 is so selected as to extend the beam 3 to the surface of the work 8, whereby the beam 1 and the beam 3 are both focused at the point 9.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cutting device using a non-RJT laser such as a CO2 laser.

Conventional non-town vision lasers such as C02 lasers have a beam output power of 50 δvy to 5 KVV and a high hoe density of 106 to 10' vV/cm, so they are suitable for cutting metal and insulating materials, welding, hardening, etc. Widely used. However, if the wavelength range is YAG laser, 1
．． 06μm, 10.6μm for CO2 laser, l
! : Since it is outside the visible range, handling the laser beam is extremely dangerous, and it can be dangerous not only to the laser equipment but also to the human body. Therefore, we set the laser device to pass through the same optical path as the non-town visibility laser beam, t(e −
A method of superimposing a visible light beam such as an rJ e laser so that the optical path along the way is visible, guiding the invisible laser beam emitted from the laser resonator to the processing point, and directing irradiation of the distorted processing point with the visible light beam. is being carried out.

Figure 1 shows C superimposed on Me -rJe L/-the beam.
1 is a partial view of a conventional laser processing apparatus in which an O2 laser beam is focused onto a workpiece with a concave mirror; FIG. The CO2 laser beam is indicated by a dotted line 1, and is usually a beam whose distribution is symmetrical about the axis 5 of the laser beam.

rie-NefX, which visible laser beam 3 is CO2
It is arranged coaxially with the axis 6 of the laser. The visible light laser beam 3 may be annular, or may be discretely distributed as a line or point beam on the circumference about the axis 5. The laser beam is focused onto the surface 9 of the workpiece 8 using a concave mirror 6 .

By using the concave mirror 6, the C
O2 laser beams 1 and 2 and He-Ne laser beam 3,
4 is focused on substantially the same point 9 on the workpiece 8 regardless of the material of the concave mirror 6. However, since the angle formed by the axis 7 of the concave mirror 6 and the axis 6 of the laser beam cannot be 0 degrees, the focused spot will include coma aberration, making it impossible to obtain a good quality spot for laser processing.

FIG. 2 shows a condensing system of a conventional laser processing apparatus designed to reduce coma aberration, using a flat reflecting mirror 11 and a condensing lens 12.

The CO2 laser beam 1.2 and the i(e-N e laser beam 3.4, which share the same axis 6 and are incident parallel to each other, are focused by the plane reflector 11 and reflected toward the /z 12.1
2 is a condensing lens, and since the condensing lens 12 is a transparent optical component, the axis of the Y7 lens 12 and the axis 6 of the laser beam can be precisely aligned. Therefore, the comatic aberration of the spot 9 on the workpiece 8 can be extremely reduced. At this time, the focal length f of the lens 12 is: where n is the refractive index and r 1. r2 is the curvature of the lens surface. However, in general, the refractive index n is a function of the wavelength of light. For example, in the case of Zn5e, a material used in the optical components of a CO2 laser, the refractive index n is a function of the wavelength t of 0.633 μm (for an e-Ne laser beam, n ” = 2.
6. Since n=2.4 for a CO2 laser beam with a wavelength of 10.6 pm, there is a difference in focal length between the CO2 laser beam and the r(e-N o laser beam in the case of FIG. 2). That is, fHe−N8:fco2=
1.4: 1.6. Therefore, when the C02 laser beam 1.2 is focused on a point 9 on the workpiece 8, J(e
-Ne The laser beam spreads out as shown in 13.14, making it impossible to accurately indicate the processing point.
1. The present invention solves the above-mentioned conventional drawbacks and provides a laser machining T device in which a non-i'T viewing laser beam for processing and a guiding laser beam are focused on the same point. It is something.

FIG. 3 shows a laser T-apparatus according to an embodiment of the present invention. In this embodiment, the visible light beam 3 superimposed around the axis 5 of the C02 laser beam 1 is reflected by a plane reflecting mirror 11 and guided to a converging lens 12 aligned with the axis 6.

In the case of the present invention, a non-OT optical laser (C02 laser) beam 1 is present in the center of the axis 6, and a visible laser beam 3 is provided in the outer region of the non-visible laser beam 1. The visible laser beam 3 may be ring-shaped or may be spot-shaped discretely along the outer periphery of the non-visible laser beam 1.

The condensing lens 12 is supported by a holder 15, and
In order to align the axis of the lens 12 and the optical axis 5, it has an adjustment mechanism that can be slightly moved. 16 condenses light with the flat reflecting mirror 11/Z1
2, this diverging lens 1
Reference numeral 6 has an opening in the center, through which the invisible laser beam 1 passes. - Since the optical laser 3 is diverged by the peripheral concave portion of the lens 16, the focal position after passing through the condenser lens 12 can be made longer. 4 and 6 show the specific structure of the diverging lens 16. Figure 4 shows a lens with a concave surface and an opening in the center, and Figure 6 shows a lens with a concave surface and a width equal to the diameter of the invisible laser beams 1 and 2. It was removed in strips.

In either case, by selecting a focal length of divergence/z 16, the visible laser beam 3 can be extended to the surface of the workpiece 8, and the invisible laser beam 1 and the visible laser beam 3 can be The focal points 9 can be made coincident. When a CO2 laser beam and a tie-1" Je laser beam are combined and Zn5e is used as the condensing lens 12, fde-No"fC○-1,4: 1.
The focal length of the diverging lens 16 may be determined so as to compensate for the relationship e.

17 is a holder for the diverging lens 16 that diverges the visible light laser beam for superimposition, and can be moved slightly in the vertical and horizontal directions so as to align the optical axis 5 with the I-pongee of the diverging lens.
].

Although we have described the case where the diverging lens 16 is installed between the focusing lens 11 and the condensing lens 12, the same effect can be obtained even if the diverging lens 16 is inserted between the condensing lens 12 and the workpiece 8. has.

According to the present invention, it is possible to match the irradiation points of the visible laser beam and the non-visible laser beam, thereby improving the accuracy of laser processing.

As described in [2] above, the present invention provides a laser processing device in which a visible laser beam is superimposed on an invisible laser beam for processing, by providing a divergence/splash that causes only the visible laser beam to diverge. Since the laser beams are focused at the same position, the position of the laser processing point can be accurately specified and highly accurate laser processing can be performed.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of a conventional laser processing device using a concave mirror, Fig. 2 is a schematic diagram of a conventional laser processing device using a combination of a concave mirror and a lens, and Fig. 3 is an embodiment of the present invention. FIGS. 4 and 5 are perspective views showing an example of the configuration of a diverging lens used in the present invention. 1...-CO laser beam for processing, 3...
・Visible laser beam, 5... Central axis of laser beam, 6... Concave mirror, 7... Axis of concave mirror, 8... Workpiece, 9...Focal length of laser beam, 11...-Reflector, 12...
---Focusing lens, 1314 ---He-11e
Laser irradiation point on workpiece, 15...Lens holder, 16...Divergent lens for visible light beam, 17
・・・・・・−Divergent lens holder for visible light beam. Name of agent: Patent attorney Toshio Nakao and 1 other person11
111゜Figure 1Figure 2Figure 3Figure 4Figure 5

Claims (1)

[Claims] It is configured to condense a non-visible laser beam on which a ρ1 visible laser beam is superimposed through a condenser lens, and the visible laser beam is coaxial with the non-visible laser beam, and the non-visible laser beam is coaxial with the non-visible laser beam. It is provided on the outer periphery of the beam,
A laser processing device characterized in that a diverging lens having a concave surface and having a cutout portion that penetrates a non-town vision laser beam region is provided at the front or rear of the condensing lens.