JPS5837073B2 - Laser Sosa Souchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for processing a workpiece by linearly scanning it in one direction while irradiating the workpiece with laser light at right angles.

Conventionally, in this type of device, which processes the workpiece by scanning the workpiece with laser light without moving it, if the laser oscillator is installed so that the laser light irradiates the workpiece in a direction perpendicular to the workpiece,
A mechanism in which at least two reflecting mirrors (mainly dichroic mirrors are used) tilted at an angle of 5° are arranged, and one of these reflecting mirrors, which is located farthest from the laser oscillator, is moved linearly, or In the case of focusing, a mechanism is known in which a condensing lens that moves in synchronization with one of the reflecting mirrors is combined.

However, in all of the above devices, the movement of the reflecting mirror affects the linearity of laser beam scanning and the straightness of the laser beam to the workpiece, which impairs the accuracy of laser beam irradiation to the workpiece, which is inconvenient for laser processing. was there.

In particular, when a reflecting mirror and a condensing lens are combined, there is a problem in the accuracy of synchronous movement, and the mechanism must also be complicated.

This invention was made in order to eliminate the above-mentioned disadvantages.The optical axis of the laser beam is shifted and rotated, and the rotated laser beam is transmitted through a cylindrical lens. This allows processing to be performed under scanning with a laser beam.

Hereinafter, the present invention will be explained based on drawings showing embodiments.

In FIG. 1, a laser oscillator 1 is provided which is arranged to oscillate a laser beam 1a in the horizontal direction, and the laser beam 1a is disposed in a horizontal direction.
On the optical path a, there is disposed a mirror 2 tilted at 45° with its reflective surface facing downward.

Furthermore, a scanning optical system 4 consisting of a first semi-cylindrical lens 3a with its flat side facing downward and a parallel prism tilted at a constant angle is placed on the optical path of the reflected laser beam 1b reflected by the above-mentioned Guikroitsuk mirror 2; A second semi-cylindrical lens 3b is sequentially disposed so that its plane side faces the plane side of the first semi-cylindrical lens 3a and extends in an axial direction perpendicular to the first semi-cylindrical lens 3a.

Incidentally, the scanning optical system 4 is held by a holder 5 which is rotated coaxially with the reflected laser beam 1b by a drive mechanism (not shown).

Laser beam scanning will be explained using the above configuration.

A laser beam 1a emitted from a laser oscillator 1 is reflected by a dichroic mirror 2 into a vertically directed downward reflected laser beam 1b.

The laser beam 1b passes through the first semi-cylindrical lens 3a, and the transmitted light enters the scanning optical system 4 in the convergence direction of the semi-cylindrical lens 3a.

The optical axis of the reflected laser beam 1b is shifted by a certain distance according to the above-mentioned inclination angle of the scanning optical system 4.

By the way, since the scanning optical system 4 is rotating coaxially with the reflected laser beam 1b as shown by arrow A, the scanning optical system 4 rotates coaxially with the reflected laser beam 1b.
is incident on the second semi-cylindrical lens 3b by the scanning optical system 4 while drawing a circular locus having the radius of the above-mentioned shifted distance.

Therefore, each spot transmitted through the second semi-cylindrical lens is focused at each position on a straight line by the focusing action of this lens and collected as a point, thereby forming a straight line locus.

As described above, this invention rotates the optical path of the laser beam while optically shifting it, and optically converts it into a linear trajectory with excellent straightness and straightness that allows reciprocating movement. Not only can the linear scanning speed of the optical spot be increased with high precision, but mechanical fluctuations such as minute rotational irregularities in the scanning optical system can be eliminated by straight lines in the linear trajectory of the laser beam spot obtained by passing through a semi-cylindrical lens. Since it does not affect the degree or straightness, machining efficiency has improved and machining accuracy has been significantly improved.

In the above embodiment, a semi-cylindrical lens is used, but it goes without saying that the effects produced by a cylindrical lens are the same.

FIGS. 2 and 3 show other embodiments in which the parts of the scanning optical system in the above embodiment are changed. First, the one shown in FIG. A pair of reflecting mirrors 4m and 4n are arranged facing each other at a predetermined interval and inclined at 45°.

Therefore, the optical axis of the reflected laser beam 1b is shifted and rotated by the distance between the reflecting mirrors.

Moreover, what is shown in FIG. 3 is a pair of triangular prisms 4o,
4p is used, and the tops of the prisms are arranged in opposite directions and are slightly shifted to face each other, and these other embodiments also produce the same effect as the embodiment in which the parallel prisms are tilted. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing one embodiment of the invention, and FIGS. 2 and 3 are schematic diagrams showing other embodiments of the invention. 1... Laser oscillator, 3a... First semi-cylindrical lens, 3b... Second semi-cylindrical lens,
4... Scanning optical system, 5... Holder.

Claims (1)

[Claims] 1 A laser oscillator, a first cylindrical lens into which the laser beam oscillated from the laser oscillator is incident, and a laser beam transmitted through this first cylindrical lens is incident, and the optical axis of the laser beam is parallel to the incident optical axis. an optical system that rotates the optical system to cause the laser beam to draw a circular trajectory whose radius is the distance by which the optical axis is shifted; and an axial direction perpendicular to the axis of the first cylindrical lens. and a second cylindrical lens into which the laser beam that is directed and draws the circular locus is incident.