JPS62248591A - Laser beam machine - Google Patents

Abstract

PURPOSE:To execute precise processing by providing a beam splitter, extracting part of a laser beam, and determining a laser beam intensity distribution by an image sensor and image signal processor. CONSTITUTION:A splitter 2 and a screen 3 are provided on the optical axis of a condenser lens 1 to conduct the greater part of the incident beam of the laser light onto a surface S to be processed and to conduct part thereof onto the screen 3. Since the distance between the screen 3 and the lens 1 is set equal to the distance between the surface S and the lens 1, the image equal to the irradiation beam on the surface S is obtd. on the screen 3. The laser light intensity distribution proportional to the irradiation light intensity distribution on the surface S is obtd. by the image sensor 5, an A/D converter 6 and the signal processor 7. Processing is executed while the laser light intensity distribution is kept monitored at all times, the precise processing is possible.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a laser processing machine.

<Conventional technology> In conventional laser processing machines, in order to measure the intensity distribution of irradiated light on the surface of a workpiece, a substance such as synthetic resin that absorbs laser light and melts and vaporizes is placed on the workpiece surface. The intensity distribution was determined from the distribution of the depth of holes created by laser beam irradiation.

<Problems to be Solved by the Invention> According to the above-mentioned intensity distribution measurement method, measurement is very time-consuming, and instantaneous intensity distribution measurement is impossible, and the intensity distribution may have fluctuations, vibrations, etc. The problem is that even if there is, it cannot be measured. Furthermore, since the above-mentioned substance is placed on the processed surface for measurement, there is also the problem that measurement cannot be performed during processing.

The present invention has been made to solve the above-mentioned problems all at once. It does not require any effort to measure the irradiation intensity distribution of laser light, it is possible to measure the intensity distribution instantaneously, and it is possible to measure the intensity distribution during processing. The purpose of this invention is to provide a laser processing machine that can also measure distribution.

Means for Solving the Problems> As shown in FIG. 1 corresponding to the drawings of the embodiment, the present invention is characterized by a beam splinter 2 that extracts a part of the laser beam that has passed through the condenser lens l. , an image sensor 5 that reads the image data of the laser beam extracted by the beam splinter 2, and an image that outputs the intensity distribution information of the image formed by the condenser lens 1 by introducing the output signal of the image sensor 5. The reason is that the signal processing device 7 is provided.

Effect> The beam splinter 2 extracts a part of the laser beam that has passed through the condensing lens 1 and forms an image on the image sensor 5, so that the laser beam irradiated onto the surface S to be processed is displayed on the image sensor 5. A laser beam proportional to the beam is irradiated, and by measuring this intensity distribution, the surface to be processed S
This means that the intensity distribution of the above laser beam was indirectly measured.

<Example> Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a block diagram of main parts of an embodiment of the present invention.

A laser beam output from the laser is focused by a condensing lens 1 and enters a beam splitter 2 . The beam splitter 2 directs most of the incident beam to the workpiece surface S.
Lead it up and lead a part onto screen 3. This screen 3 is arranged at a distance equal to the optical path length between the condenser lens 1 and the surface S to be processed with respect to the condenser lens l,
Therefore, an image equal to the irradiation beam distribution on the surface S to be processed is formed on the screen 3.

The bright and dark pattern appearing on the screen 3 is projected onto, for example, a two-dimensional image sensor 5 by an imaging lens 4 at the next stage. The output of the image sensor 5 is digitized by an A-D converter 6 and taken into an image signal processing device 7.

The image signal processing device 7 is a known signal processing device mainly composed of a microcomputer, for example, and stores a part of the imaging signal from the image sensor 5 in a memory, and calculates the intensity of light incident on the image sensor 5 in two dimensions. It can be analyzed into distribution data on the coordinate axes.

According to the above-described embodiment of the present invention, when the laser beam is irradiated, a beam with an intensity distribution proportional to the intensity distribution of the irradiated light onto the surface S to be processed by the condenser lens 1 is always emitted onto the image sensor 5.
By simply operating the image signal processing device 7, the instantaneous value of the laser light intensity distribution on the surface S to be processed can be indirectly measured at any time.

In addition, in the above embodiment, an example was shown in which the screen 3 and the imaging lens 4 were used to form an image of the laser beam on the image sensor 5, but the screen 3 is not necessarily necessary in FIG. In addition, the imaging system is not limited to this (for example, as shown in FIGS. 2 and 3, which are diagrams of main parts of other embodiments of the present invention,
It is also possible to provide a half mirror 21 after the beam splitter 2 so that the reflected light from the screen 3 forms an image on the image sensor 5 using the imaging lens 4. 5 may be provided so that the laser beam that has passed through the condenser lens 1 can be directly focused on the image sensor 5. Furthermore, in each of the above embodiments, it goes without saying that the processing can be performed using the transmitted light of the beam splinter 2 and the intensity distribution can be measured using the reflected light.

<Effects of the Invention> As explained above, according to the present invention, the beam splitter 2 is provided after the condenser lens 1 for condensing the laser beam onto the surface S to be processed, and the condenser lens l A part of the beam that has passed through is guided onto the image sensor 5 to form an image,
Since the configuration is such that the irradiation light intensity distribution on the processing surface S can be indirectly measured from the output signal of the image sensor 5, the irradiation spot position and intensity distribution on the processing surface S of the laser beam can be easily determined. Can be measured in a short time.

In addition, by storing the output of the image sensor 5 in memory, it is not only possible to measure the intensity distribution instantaneously, but also to perform indirect measurement, so measurement can be performed with the workpiece attached. Furthermore, instant measurement is possible even during processing, allowing precise measurement of the relative position between the workpiece and the laser beam irradiation spot, fluctuations in the irradiation spot on the workpiece surface S, and changes in intensity distribution over time. It has also become possible to respond to changes in the precision of processing by, for example, making corrections using a servo mechanism or outputting an i-report signal.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of main parts of an embodiment of the present invention, Figures 2 and 3.
Each figure is a main part configuration diagram of another embodiment of the present invention.

Claims (1)

[Claims] A beam splitter that extracts a part of the laser beam that has passed through the condensing lens, and a beam splitter for extracting a part of the laser beam that has passed through the condensing lens, in a device that processes the workpiece by condensing the output beam from a laser onto the surface of the workpiece using a condensing lens. and an image signal processing device that inputs the output signal of the image sensor and outputs intensity distribution information of the image formed by the condensing lens. Features: Laser processing machine.