JPH0337248Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a laser beam correction device for focusing a laser beam in parallel, and particularly to a device for preventing curvature of its output window.

[Conventional technology]

FIG. 2 is a schematic explanatory diagram showing a conventional laser beam correction device. In the figure, 1 is an oscillator, and 3 is between a correction device 2 provided on the output side of the oscillator 1 (on the right side of the drawing) and the oscillator 1. 4 is a first bend mirror that reflects the laser beam 5a transmitted through the output window 3 downward;
6 is a concave mirror that focuses the laser beam 5b reflected from the first bend mirror 4 in parallel and reflects it upward; 7 is a concave mirror that directs the laser beam 5c that has been reflected from the concave mirror 6 in the direction of a processing head (not shown). This is a second bend mirror that reflects the light toward the right side of the drawing, and the inside of the oscillator 1 is in a vacuum, and the inside of the correction device 2 is at atmospheric pressure.

The conventional laser beam correction device is configured as described above, and the laser beam 5 output from the oscillator 1
The light a is transmitted through the output window 3 and reflected downward by the first bend mirror 4. Since the laser beam 5a outputted from the oscillator 1 is slightly diffused, it is reflected by the first bend mirror 4 and then reflected upward by the concave mirror 6 while being corrected to be parallel. The laser beam 5c reflected by the concave mirror 6 is reflected and output by the second bend mirror 7 in the direction of a processing head (not shown) (to the right in the drawing).

[Problem that the invention attempts to solve]

In the conventional laser beam correction device as described above, the inside of the oscillator 1 is a vacuum and the inside of the correction device 2 is at atmospheric pressure, so if the window absorbs a part of the laser beam and the temperature rises, the output will decrease. There was a problem in that the window 3 was curved in the direction of the oscillator 1, as shown by the two-dot chain line 3a, and the output window 3 became a lens, causing the output laser beam 5a to be distorted.

This invention was made in order to solve these problems, and aims to provide a laser beam correction device that can output a laser beam without curving the output window and without distorting the laser beam.

[Means for solving problems]

The laser beam correction device according to this invention includes a condensing lens facing an output window of an oscillator, a buffer chamber is formed between the output window and the condensing lens, and the pressure in the buffer chamber is adjusted to the desired level. The pressure is intermediate between the pressure inside the oscillator and atmospheric pressure.

[Effect]

In this invention, the atmospheric pressure is weakened by the condensing lens and acts on the output window, thereby suppressing the curvature of the output window.

〔Example〕

FIG. 1 is a schematic explanatory diagram showing one embodiment of this invention, and 1 to 5 are completely the same as the conventional device described above, and their explanation will be omitted. 8 is a condensing lens provided facing the output window 3, and a buffer chamber 9 is formed between the output window 3 and the condensing lens 8. The condenser lens 8 is made of KC, like the output window 3, in order to reduce absorption of the laser beam.
Further, the pressure in the buffer chamber 9 is set to be between the pressure inside the oscillator 1 and the atmospheric pressure. For example, when the pressure inside the oscillator 1 is 70 Torr and the atmospheric pressure is 760 Torr, the pressure in the buffer chamber 9 is set to about 200 to 500 Torr.

In the laser beam correction device configured as described above, the atmospheric pressure is weakened by the condenser lens 8 and acts on the output window 3, so that the curvature of the output window 3 is suppressed.

[Effect of idea]

As explained above, this idea is to provide a condenser lens facing the output window of the oscillator, form a buffer chamber between the output window and the condenser lens, and control the pressure in the buffer chamber within the oscillator. By setting the pressure to be intermediate between the pressure of 1 and the atmospheric pressure, there is an effect of suppressing the curvature of the output window due to the atmospheric pressure and eliminating distortion of the laser beam.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing an embodiment of this invention, and FIG. 2 is a schematic explanatory diagram of a conventional laser beam correction device. In the figure, 1 is an oscillator, 2 is a correction device, 3 is an output window, 4 is a bend mirror, 5 is a laser beam, 8 is a condenser lens, and 9 is a buffer chamber. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims for Utility Model Registration] (1) In a laser beam correction device for collimating and correcting a laser beam output from an oscillator, a condensing lens is provided opposite to the output window of the oscillator, and the output window and A laser beam correction device characterized in that a buffer chamber is formed between the condenser lens and the pressure in the buffer chamber is set to an intermediate pressure between the pressure inside the oscillator and atmospheric pressure. (2) The laser beam correction device according to claim 1, wherein the pressure of the buffer chamber is 200 to 500 Torr, and the pressure of the oscillator is 70 Torr.