JP2005028428A - Laser beam machining device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser beam machining device capable of controlling the inside diameter and/or outside diameter of ring-shaped laser beams. <P>SOLUTION: The laser beam machining device 1 is provided with: an expander 21 and a collimator 22 receiving laser beams 2 output from a laser oscillator 10 and emitting the parallel laser beams 2 with a prescribed size; and a pair of optical elements 23 receiving the laser beams 2 emitted from the collimator 22 and emitting the parallel ring-shaped laser beams 2b as an optical means 20. The distance between the expander 21 and the collimator 22 and/or the distance between the optical elements 23 is optionally controlled. Thus, the inside diameter and/or outside diameter of the ring-shaped laser beams 2b emitted to the surface of a work 30 can be controlled without exchanging a lens or the like. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a laser processing apparatus that performs processing by irradiating a surface of a workpiece with a ring-shaped laser beam.

  Conventionally, there is a laser processing apparatus that performs processing (welding, exposure, drilling, etc.) by irradiating a workpiece with laser light. As such an apparatus, the present applicant has previously filed Japanese Patent Application No. H13-359768.

  This apparatus is equipped with a diffractive optical component (diffractive lens) having an uneven step shape in order to split a single laser beam into a plurality of laser beams, and by making the uneven step shape into a predetermined shape. The single laser beam can be, for example, a ring-shaped laser beam. Therefore, even when the welded portion of the workpiece is ring-shaped, it is possible to perform batch welding by irradiating the welded portion of the workpiece with the ring-shaped laser light through the condenser lens.

  However, in the case of the above-described apparatus, the inner / outer diameter ratio of the ring-shaped laser beam is determined by the uneven step shape of the diffractive optical component. Accordingly, it is conceivable that different processing shapes (inner diameter and / or outer diameter) cannot be dealt with unless the diffractive lens is replaced, for example.

  In view of the above problems, an object of the present invention is to provide a laser processing apparatus capable of controlling the inner diameter and / or outer diameter of a ring-shaped laser beam.

  In order to achieve the above object, a laser processing apparatus according to claim 1 is provided with a laser oscillator that outputs laser light and optical means for making the laser light into a ring shape. The workpiece is processed. At this time, the optical means expands the laser beam output from the laser oscillator and adjusts it to a parallel laser beam with a predetermined diameter, and a pair of parallel laser beams with a predetermined diameter as ring-shaped parallel light. And an inner diameter and / or outer diameter of the ring-shaped laser beam on the workpiece surface by controlling the distance between the expander and the collimator and / or the distance between the optical elements. And

  In the laser processing apparatus of the present invention, the laser light output from the laser oscillator is expanded by the expander and is converted into parallel laser light having a predetermined diameter by the collimator. This laser light is shaped into a ring shape by one optical element, and is made into a ring-shaped parallel light by the other optical element. At this time, the inner diameter of the ring-shaped laser beam on the surface of the workpiece changes depending on the distance between the expander and the collimator (the outer diameter of the parallel laser beam having a predetermined diameter). Further, the inner and outer diameters of the ring-shaped laser light change according to the distance between both optical elements. Therefore, the laser processing apparatus of the present invention controls the inner diameter and / or the ring-shaped laser beam on the surface of the workpiece by controlling the distance between the expander and the collimator and / or the distance between the optical elements constituting the optical means. The outer diameter can be controlled. That is, the inner / outer diameter ratio of the ring-shaped laser beam can be changed so as to correspond to various processed shapes without changing lenses for each processed shape as in the prior art.

  Further, in the laser processing apparatus of the present invention, when the ring-shaped laser beam is formed, the annular opening (aperture) is not used, and the light amount loss can be suppressed, so that the laser beam output from the laser oscillator can be suppressed. Energy can be used effectively.

  The optical element is not particularly limited as long as it is a combination capable of condensing laser light in a ring shape and making it parallel light. As a specific example, a pair of axicon lenses in which conical surfaces are arranged to face each other as described in claim 2 can be given.

  According to a third aspect of the present invention, the optical means preferably has an adjustment lens for converging or expanding the ring-shaped laser beam. By providing an adjustment lens between the pair of optical elements and the workpiece, the ring-shaped laser beam can be converged or enlarged while maintaining the shape and the inner / outer diameter ratio constant, so that the workpiece surface can be irradiated. The processable width can be increased.

Hereinafter, preferred embodiments of the present invention will be described. The laser processing apparatus of the present invention is an apparatus for processing a workpiece by irradiating the surface of the workpiece with a ring-shaped laser beam, for example, cutting a material such as resin, metal, ceramic, It can be used for processing such as drilling, welding and exposure.
(First embodiment)
An embodiment of the laser processing apparatus of the present invention will be described with reference to FIG. 1A and 1B show a laser processing apparatus according to the present embodiment, in which FIG. 1A is a schematic configuration diagram thereof, and FIG. 1B is a plan view of a workpiece surface viewed from a laser beam irradiation side.

  As shown in FIG. 1, the laser processing apparatus 1 according to the present embodiment includes a laser oscillator 10 that outputs a laser beam 2 and an optical unit 20 that receives the laser beam 2 and emits a ring-shaped laser beam. The

The laser beam 2 output from the laser oscillator 10 is not particularly limited, and for example, a YAG laser, a CO ₂ laser, an excimer laser, or the like can be used. In this embodiment, it is assumed that a laser oscillator 10 that oscillates a YAG laser having a wavelength of 1064 nm is used. The laser oscillator 10 includes a laser rod, which is a YAG rod-like crystal body to which an appropriate amount of Nd (not shown) is added, a pumping light source, a mirror, and the like.

  The optical means 20 includes an expander 21, a collimator 22, and a pair of optical elements 23, and is arranged so that each optical axis coincides with the optical axis of the laser light 2.

  The expander 21 is for expanding the laser light 2 output from the laser oscillator 10, and the collimator 22 is for converting the laser light 2 expanded by the expander 21 into parallel laser light 2. . Then, the outer diameter of the laser light 2 emitted from the collimator 22 is controlled by controlling the distance between the expander 21 and the collimator 22. As shown in FIG. 1, the expander 21 and the collimator 22 in the present embodiment have a so-called Kepler type configuration in which two convex lenses are combined. However, any other combination can be used as long as the laser beam 2 can be enlarged to obtain a parallel laser beam 2 having a predetermined diameter. For example, even a so-called Galileo-type configuration combining two concave and convex lenses good.

  The pair of optical elements 23 receive parallel laser light 2 having a predetermined diameter and emit ring-shaped parallel light. In the present embodiment, a pair of axicon lenses 23 a and 23 b are used as an example of the optical element 23. The axicon lenses 23a and 23b are optical devices that create a line image from a point light source along the optical axis, and are frustoconical lenses that do not have a clear focal length. The axicon lenses 23a and 23b are arranged such that the conical axis thereof coincides with the optical axis of the laser light 2 and the conical surfaces thereof face each other.

  When the parallel laser beam 2 having a predetermined diameter is incident from the plane side of the axicon lens 23a, the laser beam 2 is condensed into a ring shape when emitted from the inclined surface and the apex of the conical surface, and the ring-shaped laser beam 2b (hereinafter referred to as ring) is collected. Shaped beam 2b) is formed. Here, in order to make the ring-shaped beam 2b parallel light, the same lens as the axicon lens 23a is used for the axicon lens 23b in the present embodiment. In addition to this, any one having the same inclination angle and refractive index of the conical surfaces of the axicon lenses 23a and 23b can be applied. Accordingly, the ring-shaped beam 2b incident from the conical surface of the axicon lens 23b is emitted from the plane side as a parallel ring-shaped beam 2b, and is irradiated onto the workpiece 30.

  As the optical element 23, any combination other than the axicon lenses 23a and 23b can be applied as long as the laser beam 2 can be converted into a parallel ring beam 2b. For example, the axicon lenses 23a and 23b have conical conical surfaces, but lenses having other conical surfaces (for example, pyramids) may be used.

  Thus, the laser processing apparatus 1 of the present embodiment forms a parallel ring-shaped beam 2b from the laser light 2, and irradiates the surface of the workpiece 30 with the ring-shaped beam 2b as shown in FIG. be able to. Accordingly, even if the single spot laser beam is scanned or the workpiece 30 side is moved relative to the single spot laser beam and the workpiece 30 is not processed into a ring shape, the ring-shaped processing is performed collectively. It can be carried out.

  Next, the inner and outer diameter control of the ring beam 2b, which is a feature of the present invention, will be described with reference to FIG. FIG. 2 is a supplementary diagram for explaining the inner and outer diameter control. (B) The distance control between the expander 21 and the collimator 22 with respect to the reference state of (a), (c) Between the axicon lenses 23a and 23b. It is a figure which shows distance control of. The laser processing apparatus 1 has the same configuration as described above, and the laser oscillator 10 is omitted in FIG. 2 for convenience.

  The laser processing apparatus 1 of the present invention controls the distance between the expander 21 and the collimator 22 and / or the distance between the axicon lenses 23a and 23b (between the optical elements 23), thereby forming a ring shape on the workpiece 30. The inner diameter and / or outer diameter of the beam 2b can be controlled. Therefore, the inner / outer diameter ratio of the ring-shaped beam 2b on the workpiece 30 can be arbitrarily controlled. As shown in FIG. 1B, the inner diameter of the ring-shaped beam 2b is D1, and the outer diameter is a portion D2.

  First, the positional relationship among the expander 21, the collimator 22, the axicon lenses 23a and 23b, and the workpiece 30 shown in FIG.

  When the distance between the expander 21 and the collimator 22 is increased as shown in FIG. 2B, for example, with respect to the reference state of FIG. 2A, the laser light 2 expanded by the expander 21 is further expanded. Therefore, the outer diameter of the parallel laser light 2 emitted from the collimator 22 is larger than that in FIG. Here, when the distance between the axicon lenses 23a and 23b maintains the state of FIG. 2A, the outer peripheral portion of the ring-shaped beam 2b condensed from the apex of the conical surface of the axicon lens 23a is Since the light enters the same position on the conical surface of the axicon lens 23b, the outer diameter of the ring-shaped beam 2b irradiated on the workpiece 30 does not change. However, since the ring width of the ring-shaped beam 2b condensed by the axicon lens 23a is increased by the increase in the outer diameter of the laser light 2 emitted from the collimator 22, the conical surface of the axicon lens 23b is enlarged. The inner diameter of the incident ring beam 2b becomes smaller. Accordingly, the inner diameter of the ring-shaped beam 2b irradiated on the workpiece 30 is reduced. Thus, by controlling the distance between the expander 21 and the collimator 22, the inner diameter of the ring-shaped beam 2b on the workpiece 30 can be controlled. In FIG. 2B, only the collimator 22 is moved to change the distance between the expander 21 and the collimator 22, but only the expander 21 may be moved, or both may be moved together. Also good. Needless to say, the distance may be shorter than the reference state.

  Further, as shown in FIG. 2C, when the distance between the axicon lenses 23a and 23b is shortened with respect to the reference state of FIG. 2A, the parallel ring beam 2b emitted from the axicon lens 23b. The inner and outer diameters of both are smaller than in FIG. In FIG. 2C, only the axicon lens 23b is moved to change the distance between the axicon lenses 23a and 23b. However, only the axicon lens 23a may be moved, or both of them may be moved together. It may be moved. Needless to say, the distance is not only shortened but may be longer than the reference state.

  As described above, the laser processing apparatus 1 of the present invention arbitrarily combines the distance between the expander 21 and the collimator 22 constituting the optical unit 20 and / or the distance between the axicon lenses 23a and 23b (between the optical elements 23). Thus, the inner and / or outer diameter of the irradiated ring-shaped beam 2b on the workpiece 30 can be controlled. That is, it is possible to cope with various processed shapes without exchanging the lens, for example, even if the inner / outer diameter ratio is different. Therefore, it is not necessary to hold various lenses according to the processing shape and to exchange lenses, so that the cost can be reduced and the trouble of adjusting the optical axis can be saved.

  In the laser processing apparatus 1 of the present invention, the ring-shaped beam 2b is formed without using an annular opening (aperture), and the loss of light amount can be suppressed, so that the laser output from the laser oscillator 10 can be suppressed. The energy of light 2 can be used effectively. That is, since it is not necessary to use a high-performance laser oscillator 10 in order to increase the light intensity of the laser beam 2, the cost can be reduced.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made.

  In the present embodiment, an example in which the optical unit 20 includes the expander 21, the collimator 22, and the pair of optical elements 23 is shown. However, in the above configuration, the workpiece 30 is irradiated with the ring-shaped beam 2b as parallel light. Therefore, the optical means 20 may include an adjustment lens 24 for converging or expanding the ring beam 2b. In this case, as shown in FIG. 3, the adjustment lens 24 (in this case, the condenser lens is illustrated) is arranged between the optical element 23 and the workpiece 30 so that the optical axis of the lens coincides with the optical axis of the laser beam 2. Placed in. Therefore, the ring-shaped beam 2b emitted from the optical element 23 is converged or expanded by the adjusting lens 24 while keeping the shape and the inner / outer diameter ratio constant, and is irradiated onto the workpiece 30. At this time, the processable width can be further increased by moving the adjustment lens 24 to change the distance to the workpiece 30.

The laser processing apparatus of this invention is shown, (a) is the schematic block diagram, (b) is the top view which looked at the workpiece surface from the laser beam irradiation side. It is a supplementary figure for demonstrating the inner and outer diameter control of a ring-shaped beam, and is a figure which shows (a) reference | standard state, (b) distance control between an expander and a collimator, and (b) distance control between axicon lenses. . It is a schematic block diagram which shows the modification of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Laser processing apparatus 2 ... Laser beam 2b ... Ring-shaped beam 20 ... Optical means 21 ... Expander 22 ... Collimator 23 ... Optical element 23a, 23b ... Axis Conlens 30 ... Workpiece

Claims (3)

A laser processing apparatus comprising: a laser oscillator that outputs laser light; and optical means for making the laser light into a ring shape, and processing a workpiece with the ring-shaped laser light,
The optical means includes a pair of expanders and collimators that expand the laser light output from the laser oscillator to make parallel laser light with a predetermined diameter, and a pair of parallel laser light with the predetermined diameter used as ring-shaped parallel light. An optical element,
A laser processing apparatus, wherein an inner diameter and / or an outer diameter of the ring-shaped laser beam on the surface of the workpiece is controlled by a distance between the expander and the collimator and / or a distance between the optical elements. The laser processing apparatus according to claim 1, wherein the pair of optical elements are a pair of axicon lenses arranged so that conical surfaces face each other. The laser processing apparatus according to claim 1, wherein the optical unit includes an adjustment lens for converging or enlarging the ring-shaped laser beam.

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