JPS616619A - Chopper mirror - Google Patents

Abstract

PURPOSE:To obtain the chopper mirror which has high precision and long life and generates no noise by forming a material which reflects laser light on part of a surface of a substrate where laser light is transmitted. CONSTITUTION:When a CO2 laser is used for laser light with respect to a chopper mirror used for a laser working machine, etc., ZnSe where the CO2 laser is not transmitted is used for the substrate 4, and the surface is polished to prevent damage when the laser light is transmitted. Then, gold is vapor-deposited on part of the surface as a reflecting part 5, and the area where no gold is vapor-deposited is a transmission part 6. The laser light 7 is reflected by the reflecting part 5 to obtain laser light 7-1, but transmitted at the transmission part 6 to travel as laser light 7-2. Thus, hole work for a window on the substrate 4 is not necessary, so the smoothness of the surface is improved and when this is used while rotated, its dynamic balance is good, so high-precision rotation is realized, so that the precision of the chopper mirror is high. Further, there is no strain because of the work, so there is no aging change in smoothness.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a chopper mirror used in a laser processing machine that performs processing using laser light.

Conventional configuration and problems thereof A chopper mirror is composed of a portion through which laser light is transmitted or reflected, and is used to split one laser beam into two or more parts. Here, FIG. 1 shows a conventional example of a chopper mirror. The same figure (-) is a front view, the same figure (b)
is a cross-sectional view taken along line A-A' in the same figure (→). A hole 2 for transmission is made on the substrate 1. The surface of the substrate 1 is mirror-finished to have a reflectance of 98 cm or higher. .Center 3
It rotates around the axis and chops the laser beam. This chopper mirror has the following problems. First, since holes are formed in the substrate 1, the flatness of the substrate 1 cannot be improved, and deterioration occurs over time.

Second, when the chopper mirror is rotated and used, wind noise is generated due to the presence of the holes 2, resulting in noise.

Also, since air is drawn in, the air hits the reflective surface and dust in the air damages the mirror surface. Thirdly, the thickness of the substrate 1 causes the beam to be distorted, so the hole shape becomes larger than necessary, and the shape of the chopper mirror becomes large.

OBJECTS OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and provide a chopper mirror that is highly accurate, has a long life, and does not generate noise.

Constituent Structure of the Invention The object of the present invention is to provide a chopper mirror that achieves the above object by forming a material that reflects laser light on a portion of the surface of a substrate that transmits laser light.

DESCRIPTION OF EMBODIMENTS FIG. 2 shows a general view of a chopper mirror in an embodiment of the present invention. This embodiment is a chopper mirror in which a C02 laser is used as the laser beam. The material of the substrate 4 is Zn5e, which transmits C02 laser light.

The surface is polished so that it will not be damaged when laser light passes through it. Gold is vapor-deposited on a part of its surface as a reflective part 6.

The region on which gold is not vapor-deposited becomes a transparent section 6. FIG. 3 shows an example in which the chopper mirror of this embodiment splits laser light. The laser beam 7 is reflected by the reflecting section 5 and becomes a laser beam 7-1, while it travels through the transmitting section 6 as a laser beam 7-2. Since the chopper mirror configured in this way does not require drilling holes for windows on the substrate 4, it is possible to improve the flatness of the surface, and it also has good dynamic balance when used in rotation, so it can be used in high Accurate rotation is possible, making it a highly accurate chopper mirror. Also, since there is no distortion due to processing, there is no change in flatness over time. Since the substrate 4 transmits the laser beam, the diameter of the chopper mirror can be determined without changing the thickness of the substrate 4, which allows miniaturization.

Furthermore, since the chopper mirror surface of this embodiment has no irregularities, no wind noise is generated when the chopper mirror rotates at high speed, and there is no noise problem. Also, since the amount of air drawn in during rotation is small, the surface is less likely to be damaged by dust in the air.

It goes without saying that the substrate of the present invention may be made of any other material as long as it transmits the laser beam used.

Effects of the Invention In summary, the present invention provides a chopper mirror characterized by forming a material that reflects laser light on a part of the surface of a substrate made of a material that transmits laser light, and which is highly accurate. can be maintained for a long time, and can also suppress the generation of noise.

[Brief explanation of the drawing]

Fig. 1(a) is a front view of a conventional chopper mirror, Fig. 1(b) is a sectional view at p, -A' in Fig. 1(a),
The figure is a front view of a chopper mirror in one embodiment of the present invention, and FIG. 3 is a diagram illustrating an example of dividing laser light according to the present embodiment. 4...Substrate, 5...Reflector, 6...
...Transparent part. Name of agent Patent attorney Toshio Nakao and 1 other person Construction drawing ((1,)
<b Figure 2 Figure 3

Claims (1)

[Claims] A chopper mirror characterized in that a substance that reflects laser light is formed on a part of the surface of a substrate that transmits laser light.