JPS63248589A - Laser beam machining method - Google Patents

Abstract

PURPOSE:To facilitate alignment between a laser machining head and a work by constituting visible ray so as to be possible to irradiate from the laser machining head and aligning the laser machining head by using a spot of the visible radiation projected on the surface of the work as the standard. CONSTITUTION:The laser machining head 30 constitutes by a dichroic mirror 36 transmitting the laser bean radiated from a CO2 laser beam source 35 to the work 28 side and a reflection mirror 38 reflecting the visible ray radiated from an He-Ne laser beam source 37 to the dichroic mirror 36 side. The dichroic mirror 36 reflects the visible ray to the work 28 with the same beam axis as the CO2 laser beam. Before the laser machining, the CO2 laser beam source 35 is turned off, and the visible ray from the He-Ne laser beam source 37 is radiated on the work 28 and them, the light spot can be recognized on the surface of the work 28. Therefore, by adjusting this light spot so as to fall to the presetting point on the work 28, the alignment between the work 28 and the laser beam machining head 30 can be accurately executed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention aims to improve the surface of a workpiece by irradiating the workpiece with a laser beam, which is invisible light, from a laser processing head that moves relative to the workpiece. The present invention relates to a laser processing method for performing desired processing on a workpiece, and more particularly, to a laser processing method for properly and quickly aligning a laser processing head and a workpiece.

2. Description of the Related Art When a laser beam is used to perform a required process such as engraving on the surface of a workpiece such as wood, it is common to use a CO2 laser light source that can produce a high-output laser beam. Conventionally, in laser processing using this CO2 laser light source, trial processing is performed by irradiating laser processing without accurately positioning the laser processing head, and the position is corrected based on the result.

Problems to be Solved by the Invention Conventionally, it is wasteful in terms of time and cost to perform post-processing such as cutting and cutting on a workpiece after laser processing for adjustment. Further, as processing technology advances in recent years, it has become advantageous to manufacture a workpiece with accurate dimensions and accurately perform laser processing at a predetermined position on the surface of this workpiece. Furthermore, when engraving fine details and clear outlines on multiple workpieces and combining them into one product, even if there is a slight positional deviation in each engraving pattern, the overall Disharmony occurs and the product value decreases. For this reason, there is a need to develop a technique that can accurately position a laser processing head with respect to a workpiece before starting laser processing.

Purpose of the Invention The present invention has been proposed in order to suitably solve the problems inherent in the prior art described above. The object of the present invention is to provide a laser processing method that allows accurate positioning.

Means for Solving the Problems In order to suitably achieve the above object, the present invention irradiates the workpiece with a laser beam of invisible light from a laser processing head that moves relative to the workpiece. In a laser processing method for performing desired processing on the surface of a workpiece, the laser processing head is configured to be able to irradiate visible light emitted from a required optical device as a light emission source from the laser processing head with its optical axis aligned with the laser beam. Then, before the laser processing head starts moving,
The present invention is characterized in that the visible light beam is irradiated toward the workpiece, and the laser processing head is aligned based on a spot of the visible light projected onto the surface of the workpiece.

Action Before starting laser processing, visible light is irradiated from the laser processing head, and this visible light spot formed on the workpiece is
The positional relationship between the laser processing head and the workpiece is adjusted so that the laser processing head and the workpiece overlap with a point indicating the processing start position on the workpiece. The smaller the light spot projected onto the workpiece at this time, the more accurate positioning becomes possible. For this reason, as the visible light, it is preferable to use light with good convergence, such as laser light.

Embodiments Next, the laser processing method according to the present invention will be described using preferred embodiments with reference to the drawings.

FIG. 2 shows a schematic configuration of a laser processing apparatus to which a laser processing method according to an embodiment of the present invention is applied,
On the XY table 18 shown in the figure, a white pattern sheet 22 on which a desired treated pattern 20 to be subjected to the engraving method is depicted in black is placed. This pattern sheet 2
A detection head 24 of a pattern sensor relatively scans and moves on 2. A workpiece 28 made of, for example, a wooden board is placed on another XY table 26, and a laser processing head 30 is disposed above this workpiece 28 so as to be able to scan relative to the workpiece 28. has been done.

Both XY tables 18, 26 can be moved synchronously in the X and Y directions under the action of a drive mechanism (not shown). Note that the electric control circuit 32 is
An instruction signal corresponding to the detection signal sent from the detection head 24 is sent to the processing head 30, thereby controlling on/off of laser beam irradiation.

Inside the laser processing head 30, as shown in FIG.
A dichroic mirror 36 that transmits a laser beam (invisible light) with a wavelength of 10.6 μm outputted from the O2 laser light source 35 to the workpiece 28, and a dichroic mirror 36 that transmits a laser beam (invisible light) with a wavelength of 10.6 μm output from the He-N e laser light source 37 and An optical device including a reflecting mirror 38 that reflects the laser beam (visible light) toward the dichroic mirror 36 is provided. This dichroic mirror 36 has a wavelength of 632.8
The laser beam having a wavelength of 100 nm is reflected toward the workpiece 28 along the same optical axis as the Co2 laser beam.

The detection head 24 of the pattern sensor includes a light emitting diode 3
A visible laser beam outputted from 9 is emitted onto the pattern sheet 22, the presence or absence of reflected light is detected, and a detection signal of the engraving pattern 20 is sent to the electric control circuit 32.

In the laser beam engraving device having such a configuration, before laser processing, the laser processing head 30 and the workpiece 28 are
and the detection head 24 and the pattern sheet 22, respectively. In this case CO2
When the laser light source 35 is turned off and the workpiece 28 is irradiated with a laser beam from the He-Na laser light source 37, a light spot condensed and formed on the surface of the workpiece 28 can be visually recognized. Therefore, by adjusting the light spot so that it overlaps with a point previously provided on the workpiece 28 for alignment, the workpiece 28 and the laser processing head 30 can be easily and precisely aligned. Further, the pattern sheet 22 is also aligned so that the light spot emitted from the detection head 24 and condensed and formed on the pattern sheet 22 overlaps the positioning points struck on the pattern sheet 22.

After the above-mentioned positioning is completed, both xy tables 18.
26 start moving synchronously and the detection head 24 is scanning the black engraving pattern 20, a CO2 laser beam is emitted from the laser processing head 30 to the workpiece 28, and the CO2 laser beam is emitted to the workpiece 28. The surface is engraved. Furthermore, when the detection head 24 is scanning the white portion of the pattern sheet 22, the laser beam emitted from the laser processing head 30 is blocked. Both XY table 18.26
As a result of this movement, the detection head 24 scans the entire range of the engraving pattern 20, so that a pattern having the same or similar shape to the engraving pattern 20 is engraved on the surface of the workpiece 28. In this embodiment, the laser processing head 30 and the workpiece 28 and the detection head 24 and the pattern sheet 22 are precisely aligned before the engraving process, so that the engraved image is placed on the predetermined position of the workpiece 28. formed in position.

In the embodiment, the configuration is such that the XY table side is moved, but it goes without saying that the laser processing head and the detection head side may be moved. Also, He-
Instead of using the Ne laser light source, other light sources, such as a laser diode, may be used to irradiate the workpiece with visible light.

Effects of the Invention As explained above, according to the present invention, accurate alignment between the laser processing head and the workpiece can be easily achieved, and laser processing products such as engravings with high commercial value can be obtained at low cost. It has the effect of being able to.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a configuration for performing alignment in a laser processing method according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of a laser processing apparatus that executes a laser processing method according to an embodiment of the present invention. FIG. 18.26... XY table 20... Engraving pattern 22... Pattern sheet 24... Pattern sensor detection head 28...
・Workpiece 30...Laser processing head 35...CO2 laser light source 36...Dichroic mirror 37...He-Ne laser light source 38...Reflector 39...Laser diode 7-door special opening rjG3-248589 (4)° l C-toe 1°

Claims (1)

[Scope of Claims] [1] A laser processing head that moves relative to the workpiece irradiates the workpiece with a laser beam of invisible light to perform desired processing on the surface of the workpiece. In the laser processing method to be carried out, visible light emitted from a required optical device as a light emitting source is configured to be irradiated from the laser processing head with its optical axis aligned with the laser beam, and before the start of movement of the laser processing head. A laser processing method, comprising: irradiating the visible light beam toward the workpiece, and aligning the laser processing head with reference to a spot of the visible light projected onto the surface of the workpiece. [2] The laser processing method according to claim 1, wherein the optical device includes a dichroic mirror that transmits the laser beam of invisible light and allows reflection of the visible light. [3] The laser processing method according to claim 1 or 2, wherein the laser beam of the invisible light is a CO_2 laser, and the visible light is a He-Ne laser.