JP2007183669A - Method for adjusting condensing lens device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for adjusting a condensing lens device used in a laser beam machining device to perform scanning with a laser beam by a beam scanning mechanism, and the method for adjusting the condensing lens device stably and accurately assembled, and to make lenses the surface shape of which is all aspherical and the material of which is all germanium usable so as to obtain high laser beam machining quality. <P>SOLUTION: In the condensing lens device comprising a plurality of lenses, the axis of a lens is adjusted so that beam intensity distribution may be symmetric in upper and lower and right and left regions of an area which can be scanned with respect to the center of the area by using a lens holder 15 equipped with a mechanism for parallel displacing a second lens 12 in a two-dimensional direction orthogonal to an optical axis and fixing it. By using the lens holder equipped with a lens interval adjusting mechanism 19 capable of parallel displacing the lens in the optical axis direction and fixing it, and a mechanism capable of rotating the lens with the optical axis as the axis of rotation, the interval and the rotational angle of the lens are adjusted, whereby more homogeneous machining quality is obtained all over the area which can be scanned. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for adjusting a condensing lens device for scanning used in a laser processing apparatus that scans a laser beam with a beam scanning mechanism.

A condensing lens for scanning used in a laser processing apparatus equipped with a beam scanning mechanism is usually composed of a plurality of lenses, and the lens material is zinc selenide, germanium, potassium chloride, etc. that can transmit an infrared laser beam. Is used.
However, potassium chloride is rarely used due to the brittleness and deliquescence of the material itself, and germanium due to the high absorption rate of the material itself with respect to the infrared laser beam. It also helps to transmit visible light for adjusting the optical axis, and zinc selenide is often used in spite of dramatic poison.

  However, as described in Japanese Patent Laid-Open No. 2001-51191 “fθ lens” (hereinafter referred to as Patent Document 1), for example, germanium has a refractive index of 4. at an infrared laser beam wavelength of 10.6 μm. 0, which is higher than the refractive index of zinc selenide, 2.4. Compared to the case of using a lens material having a low refractive index, the use of a lens material having a high refractive index is effective in reducing the number of lenses and reducing the thickness of each component lens, because the generated aberration can be reduced. It is effective in reducing the lens material cost. In the case of germanium, if the laser oscillator has a laser output of 500 W or less, the temperature rises, but it does not melt and can be used depending on the application.

Similarly, as described in Patent Document 1, it is effective to use an aspheric surface for the lens surface shape in order to increase the degree of freedom in design. The high degree of design freedom means that the target performance can be reached even with a small number of lenses and thin lenses, and the use of an aspheric surface is also effective in reducing the lens material cost.
However, when using an aspherical surface, the processing and assembling accuracy of the lens becomes stricter than when using a spherical surface. In particular, in the case of using an aspherical surface in a high refractive index material such as germanium, the processing and assembly accuracy becomes more severe.

  In Patent Document 1, among the six examples, germanium, which is a high refractive index material, is used, but only one is used, and an aspheric surface is also used only on one side of each component lens. The reason for not using germanium as the material of each constituent lens and not using aspheric surfaces on both the front and back surfaces is not clearly described, but is due to the strict manufacturing accuracy described above.

For this reason, in a scanning condensing lens composed of a plurality of lenses, if the lens has a focal length of 100 mm, the number of lenses increases from 3 to 4 as in Patent Document 1, and the lens material cost is increased. Becomes higher.
Further, only about one germanium of a high refractive index material is used, and as described in JP-A-11-254172 “Laser processing apparatus” (hereinafter referred to as Patent Document 2), an expensive zinc selenide is used. Therefore, the lens material cost is further increased.

  In Patent Document 2, it is described that germanium is used as a condensing lens for scanning of a laser processing apparatus that scans an infrared laser beam with a beam scanning mechanism. However, the configuration and structure of the lens itself, and the present invention are described. There is no description about the manufacturing method of the lens to be solved.

Further, in the condensing lens for scanning consisting of a single-sided aspheric surface containing zinc selenide as in Patent Document 1 described above, the number of lenses is large and the thickness of each component lens is also thick. The total lens length (distance from the uppermost surface to the lowermost surface of the condensing lens for scanning) is as long as 65 to 88 mm.
As a result, the distance from the lowermost surface of the condensing lens for scanning to the workpiece (hereinafter referred to as work distance) becomes as short as 72 to 102 mm.
As a result, the contamination by the scattered processing on the lowermost surface of the condensing lens for scanning is accelerated, and the lens life is shortened. This problem becomes more prominent in the case of a lens having a shorter focal length because the work distance is further shortened.

JP 2001-51191 A Japanese Patent Laid-Open No. 11-254172

  Lens materials for laser beam transmission, such as zinc selenide and germanium, are very expensive, so the lens material cost has the highest specific gravity in the manufacturing cost of the above-described condensing lens for scanning. In order to keep the lens material cost low and manufacture a lens at a lower cost, it is desirable to use only germanium having a higher refractive index as the lens material and to use an aspherical surface on the entire lens surface.

  Furthermore, since it is a scanning condensing lens used in a laser processing apparatus, it is desirable to use a full-aspherical and all-germanium lens that can further shorten the entire lens length in order to extend the life of the lens.

  However, as described above, there is a problem that the processing and assembling accuracy of the lens becomes very strict and the yield becomes very bad.

  The present invention has been made to solve the above-mentioned problems, and since the lens surface shape is an entire aspherical surface and the lens material is all germanium, the assembly accuracy is not the lens processing accuracy. In view of the above, an object of the present invention is to provide a structure and an assembling method of a condensing lens device that can be stably and highly accurately assembled, and to be able to supply a cheaper and longer-life lens.

According to the method for adjusting a condensing lens device according to the present invention, at least one lens is arranged so that the beam intensity distribution is symmetrical in the upper, lower, left, and right areas of the area in the scanable area of the workpiece. Adjusting the position in a two-dimensional direction perpendicular to the axis, and at least one lens so that the difference in height in the optical axis direction of the condensing point group of the beam in the scannable area is reduced. It consists of the step of adjusting the position in the axial direction.
Further, at least one lens is constituted by a step of adjusting the angle with the optical axis as the rotation axis so that the beam intensity distribution is symmetric in the upper, lower, left, and right areas of the scannable area with respect to the center.

  As described above, according to the present invention, the lens axis adjustment mechanism capable of adjusting the position by translation in the two-dimensional direction orthogonal to the optical axis, and the lens capable of adjusting the position by translation in the optical axis direction. An adjustment method for a condensing lens device having an interval adjustment mechanism and a lens rotation angle adjustment mechanism capable of rotating about an optical axis as a rotation axis, wherein at least one lens is placed in a scanable area of a workpiece A step of adjusting the position in a two-dimensional direction orthogonal to the optical axis so that the beam intensity distribution is symmetric in the upper, lower, left, and right areas of the area with respect to the center; An aspherical gel that requires high assembly accuracy by comprising a step of adjusting the position in the optical axis direction so as to reduce the difference in height in the optical axis direction of the condensing point group Can be configured only by lens bromide lens, there is an effect that can provide long lifetime lens than less expensive.

  In addition, a rotationally asymmetric cylindrical surface or toroidal surface can be used for the two-dimensional scanning condensing lens, which is effective in obtaining high laser processing quality.

Embodiment 1 FIG.
1 is a block diagram showing a laser processing apparatus according to Embodiment 1 of the present invention, and particularly shows an optical system of a laser processing apparatus provided with a beam scanning mechanism.

  In FIG. 1, this laser processing apparatus irradiates a workpiece 5 placed on an XY table (not shown) with a laser beam to burn, melt, sublimate, or discolor the workpiece 5. Laser oscillator 1 that generates a single-pulse, multiple-pulse, or continuous-wave laser beam (infrared laser beam, etc.) 2 for the purpose of processing such as cutting, drilling, welding, heat treatment, or marking And galvanometer mirrors 3a and 3b for reflecting the laser beam 2 at an arbitrary angle, galvanometer scanners 4a and 4b for rotating the galvanometer mirrors 3a and 3b in response to a command from a control device (not shown), and a laser reflected by the galvanometer mirror 3b. It is mainly composed of a condensing lens device 10 that irradiates a workpiece 5 with a beam.

  Here, the galvanometer mirror 3a and the galvanometer scanner 4a that drives the galvanometer mirror 3b and the galvanometer mirror 3b and the galvanometer scanner 4b that drives the galvanometer are respectively called galvanometers. This is expressed by a functional surface that reflects and scans the laser beam to be incident on the condenser lens device 10 at an arbitrary angle, and is referred to as a beam scanning mechanism.

  Next, the processing operation by the laser processing apparatus of FIG. 1 will be described. A laser beam 2 output from the laser oscillator 1 in accordance with a frequency and output value set by a control device (not shown) is guided to galvanometer mirrors 3a and 3b which are beam scanning mechanisms, and at an arbitrary angle by galvanometer scanners 4a and 4b. The light is reflected by the held galvanometer mirrors 3 a and 3 b and enters the condenser lens device 10. The laser beam incident on the condenser lens device 10 is focused on the workpiece 5. By controlling the oscillation timing of the laser beam 2 output from the laser oscillator 1 and the angles of the galvanometer mirrors 3a and 3b with a control device (not shown), the shape input in advance to the control device can be processed.

  In FIG. 1, a dotted square on the workpiece 5 is a scannable area 6 limited by the galvanometer mirrors 3 a and 3 b and the condenser lens device 10. In FIG. 1, a pair of galvanometers are used as the beam scanning mechanism and a two-axis orthogonal two-dimensional scanning optical system is employed. However, a one-dimensional scanning optical system having only one galvanometer may be used. .

  FIG. 2 shows a cross-sectional view of a condensing lens device used in the laser processing apparatus according to Embodiment 1 of the present invention. With the configuration of the condensing lens device, it is possible to stably assemble an aspheric germanium lens with high accuracy.

  As shown in FIG. 2, the condensing lens device 10 of the present embodiment includes a first lens 11 located on the galvanometer side, a second lens 12 located on the workpiece side, and the first and first lenses. A lens barrel 16 for mounting the second lenses 11 and 12, a lens holder 15 for holding the second lens 12, and a micrometer 17 for parallelly moving the lens holder 15 in a plane perpendicular to the optical axis direction. Is the main component.

  As the first and second lenses 11 and 12, aspherical germanium lenses are used for both the front and back surfaces, their surface accuracy is 0.5 μm PV or less, surface roughness is 0.1 μm Rmax or less, and the coaxiality of the front and back surfaces is 2 μm. Hereinafter, the parallelism is processed with very high accuracy such as 50 μrad or less. A laser beam 13 scanned by a galvanometer (not shown in FIG. 2) is incident on the first lens 11 and is emitted from the second lens 12 to be processed (not shown in FIG. 2). ).

  The first lens 11 is fixed to the lens barrel 16 by screwing a ring-shaped fixing screw 14 a into the inner cylinder portion 16 a of the lens barrel 16. On the other hand, the second lens 12 is held by a lens holder 15. A micrometer 17 for translating the lens holder 15 with high accuracy is provided on one side of the lens holder 15, and a lens holder is provided on the opposite side of the micrometer 17. A spring 18 that pushes back 15 is provided. As a result, the second lens 12 can be translated in a plane orthogonal to the optical axis in accordance with the projecting or retracting operation of the tip of the micrometer 17, and the second lens can be moved with respect to the first lens 11. 12 can be positioned with an accuracy of 1 μm level.

  In actual positioning, the micrometer 17 is rotated and adjusted so that the beam intensity distribution on the workpiece of the laser beam 13a that has passed through the left side of the lens and the laser beam 13b that has passed through the right side of the lens is symmetrical. The position of the axis 11a of the second lens and the axis 12a of the second lens are adjusted. Thereafter, the second lens 12 is fixed to the lens barrel 16 together with the lens holder 15 by screwing a ring-shaped fixing screw 14 b into the inner cylinder portion 16 b of the lens barrel 16.

  Since FIG. 2 is a cross-sectional view, only one set of the micrometer 17 and the spring 18 is shown, but actually, the first lens axis 11a and the second lens axis 12a are also connected in the vertical direction of FIG. It is necessary to match. Therefore, as shown in the schematic diagram of the periphery of the second lens 12 in FIG. 3, two sets of micrometers 17 and springs 18 are arranged around the second lens 12 and the lens holder 15 so as to be orthogonal to each other. The By providing such a mechanism, it is possible to adjust the position of the second lens axis 12a with respect to the first lens axis 11a in a plane perpendicular to the optical axis with high accuracy. Symmetric processing quality can be obtained in the XY region of the scannable area 6 of the optical lens device 10.

  FIG. 4 is a partial sectional view showing another example of the condensing lens device according to Embodiment 1 of the present invention. Here, as shown in FIG. 4, it is possible to adjust the distance between the first lens 11 and the second lens 12 by providing a mechanism capable of translating the second lens 12 also in the optical axis direction. And

  In FIG. 4, an annular flat spring 18 a is inserted between the upper surface of the second lens 12 and the lens barrel 16, and a lens interval adjusting mechanism 19 having the same concept as the collet chuck is used at the lower end of the lens barrel 16. did. The lower outer peripheral portion of the lens barrel 16 is cut in the optical axis direction similar to the collet chuck (not shown). Then, by tightening the ring-shaped taper screw 19a, slip occurs between the tapered surface 19b provided on the lens barrel 16 and the annular plate 19c provided between the lens barrel 16 and the lens holder 16 and having a tapered surface. The lens holder 15 can be translated upward in the optical axis direction.

  The adjustment accuracy of the lens interval adjusting mechanism 19 is roughly determined by the outer diameter of the taper screw 19a, the screw pitch, the taper angle, and the taper angle of the taper surface 19b. For example, if the screw pitch is 1 mm and the two taper angles are both 10 °, the taper screw 19a rotates by 1/8 and the second lens 12 feeds about 4 μm in the optical axis direction. If it is φ200 mm, this corresponds to a rotation of about 80 mm in the outer circumferential direction. With a feed of 1 μm, it is possible to adjust the position with high accuracy by rotating about 20 mm.

  In this way, by adjusting the distance between the first lens 11 and the second lens 12 by the lens interval adjusting mechanism 19, the inside of the scanable area on the workpiece 24 as shown in FIG. The difference in the height in the optical axis direction of the condensing point group 22 of the laser beam group 21 irradiated to can be reduced as shown in FIG. A curved surface connecting the condensing point group 22 is called an image plane 23 of the condensing lens device 10, and an aberration that does not become a plane is called a field curvature. A lens interval adjusting mechanism 19 shown in FIG. 4 is for correcting this curvature of field. Thus, not only the position of the axis 11a of the first lens and the axis 12a of the second lens is adjusted, but also the distance between the first lens 11 and the second lens 12 is adjusted, thereby condensing light. A uniform processing quality can be obtained over the entire scanable area of the lens apparatus 10.

  As described above, by adopting the mechanism according to the first embodiment of the present invention, the condensing lens device 10 can be constituted by the lens surface shape entirely aspherical surface and the entire lens material germanium. As a result, compared with the above-mentioned Patent Document 1 (Japanese Patent Laid-Open No. 2001-51191), the number of lenses having a focal length of 100 mm, which was 3 to 4 lenses, could be reduced to 2. Further, the lens total length 65 to 88 mm was as short as 56 mm, and the work distance 72 to 102 mm was as long as 118 mm. Since the lens life is approximately proportional to the square of the work distance, the life can be increased by about 1.3 times compared to the case of 102 mm.

In the description of the first embodiment, the second lens 12 is translated with respect to the first lens 11 in a two-dimensional direction orthogonal to the optical axis or in a three-dimensional direction including the optical axis direction to perform position adjustment. However, the first lens 11 may be translated with respect to the second lens 12 in a two-dimensional direction orthogonal to the optical axis or in a three-dimensional direction including the optical axis direction.
In addition, the first lens 11 and the second lens 12 may be translated from each other in a two-dimensional direction orthogonal to the optical axis or a three-dimensional direction including the optical axis direction.

  In the description of the first embodiment, the position adjustment is performed using the micrometer 17 and the lens interval adjustment mechanism 19, but thin metal pieces are attached to the first lens 11, the second lens 12, and the lens barrel 16. The same effect can be obtained by pasting or inserting the first lens 11 or the second lens 12 between the lens holder 15 or the lens barrel 16. However, with a micrometer, adjustment is possible at the 1 μm level, but with a metal piece, adjustment accuracy is slightly deteriorated to 5 μm level.

  Furthermore, in the first embodiment, the condensing lens device 10 composed of two lenses, the first lens 11 and the second lens 12, has been described, but the same mechanism can be applied to a lens composed of three or more lenses. By using it, it is possible to obtain uniform processing quality in the entire scannable area by adjusting the axis of one or more lenses and adjusting the lens interval.

Embodiment 2. FIG.
6 is a partial plan sectional view showing a condensing lens device according to Embodiment 2 of the present invention. With the configuration of the condensing lens device according to the second embodiment, it is possible to assemble the aspheric germanium lens more stably and with higher accuracy than in the first embodiment.

In the condensing lens device according to the second embodiment, a lens rotation mechanism using a worm 31 and a worm wheel 32 is provided between the lens holder 15 of the second lens 12 and the lens barrel 16 in the configuration of the first embodiment. It is a thing. The outer periphery of the lens holder 15 is subjected to gear processing on the worm wheel 32, and the second lens 12 is disposed at the center thereof. However, the part to be subjected to gear machining should avoid a part where the micrometer 17 or the spring 18 contacts in the optical axis direction.
A worm 31 that meshes with the worm wheel 32 is provided between the lens holder 15 and the lens barrel 16. Then, by rotating the worm 31, the second lens 12 can be rotated with the optical axis as the rotation axis.

The aspherical lens is processed with high accuracy, but both the front and back surfaces of the aspherical lens should be originally rotationally symmetric, but are actually processed to be slightly asymmetrically about 0.4 μm.
Further, as described above, there is a slight deviation between the front and back surfaces in the same axis or parallel. If such an asymmetric distortion of the lens surface, a coaxial deviation of the front and back surfaces, and an asymmetry of the parallel deviation exist, even if the lens translation mechanism of the first embodiment is used, the processing is completely uniform over the entire scanable area. You can't get quality.

In order to minimize the influence of this asymmetry, the rotation angles of the two lenses are adjusted so that the asymmetry of the first lens 11 and the asymmetry of the second lens 12 cancel each other as much as possible. There is a need.
Therefore, by using the lens rotation mechanism shown in FIG. 6, the second lens 12 can be rotated with respect to the first lens 11 so that a more uniform processing quality can be obtained over the entire scanable area. It becomes possible.

  In the description of the second embodiment, the angle adjustment is performed by rotating the second lens 12 with respect to the first lens 11, but the first lens 11 is rotated with respect to the second lens 12. May be.

In the second embodiment, an example using an aspherical germanium lens that is inherently rotationally symmetric in the lens surface shape has been described. However, when an originally rotationally asymmetric cylindrical surface or toroidal surface is used, the optical axis in FIG. 6 is rotated. The lens rotation mechanism using the shaft is a more effective means.
As shown in FIG. 1 described above, an optical system of a laser processing apparatus having a beam scanning mechanism is often a two-dimensional orthogonal two-dimensional scan. For this reason, it is possible to obtain higher processing quality when the condensing lens device 10 also uses a cylindrical surface or a toroidal surface having a different cross-sectional shape in the scan biaxial direction.

However, in a condensing lens device composed of a plurality of rotationally asymmetric lenses, the directions of two axes perpendicular to the optical axis of each constituent lens must be matched between the constituent lenses.
For example, in the case where the two lenses shown in FIG. 2 are both rotationally asymmetric lenses, it is necessary to first align the two axes of the first lens 11 in the axial direction of the scanning mechanism. Next, it is necessary for the second lens 12 to have two axes aligned in both the axial direction of the scanning mechanism and the two axial directions of the first lens 11.

  As described above, by providing a lens rotation mechanism with the optical axis shown in FIG. 6 as the rotation axis in each constituent lens, a rotationally asymmetric cylindrical surface or toroidal surface can be used for the condensing lens device for two-dimensional scanning. And high processing quality can be obtained.

Embodiment 3 FIG.
FIG. 7 is a flowchart showing a method for adjusting a condensing lens device according to Embodiment 3 of the present invention, and represents a lens adjustment procedure using the condensing lens devices of Embodiments 1 and 2.

  First, in step 701, the first lens 11 and the second lens 12 are mounted on the lens barrel 16. For example, as shown in FIG. 2, the first lens 11 is mounted on the lens barrel 16 by screwing a ring-shaped fixing screw 14 a into the inner cylinder portion 16 a of the lens barrel 16. On the other hand, the second lens 12 is held by the lens holder 15 and temporarily fixed to the lens barrel 16.

Next, in step 702, the axes of the first lens 11 and the second lens 12 are adjusted.
That is, as shown in FIGS. 2 and 3, the micrometer 17 is rotationally adjusted to adjust the position of the first lens axis 11a and the second lens axis 12a. This lens axis adjustment is performed while checking whether or not the beam intensity distribution is symmetric in the vertical and horizontal areas with respect to the center of the scannable area 6 (step 703).

  Next, in step 704, the distance between the first lens 11 and the second lens 12 is adjusted. For example, as shown in FIG. 4, the interval between the first lens 11 and the second lens 12 is adjusted using a lens interval adjusting mechanism 19. This adjustment of the lens interval is performed while confirming that the difference in height in the optical axis direction of the condensing points in the scannable area 6 is reduced (step 705).

Next, in step 706, the angles of the first lens 11 and the second lens 12 are adjusted with the optical axis as the rotation axis.
For example, as shown in FIG. 6, by rotating the worm 31, the second lens 12 is rotated about the optical axis as a rotation axis to adjust the angle. The adjustment of the lens rotation angle is performed while confirming whether or not the beam intensity distribution is symmetric in the vertical and horizontal areas with respect to the center of the scannable area 6 (step 707).

In other words, the lens adjustment method according to the present embodiment is performed in the order of steps of lens axis adjustment (step 702), lens interval adjustment (step 704), and lens rotation angle adjustment (step 706). After each adjustment, a processing quality check is performed, and if the entire scannable area is uniform, the performance is achieved (steps 703, 705, and 707).
The reason why the adjustment is performed in this process order is that the process quality is greatly affected in this process order. That is, adjusting the lens axis most improves the performance of the condenser lens device.

As a result, as indicated by the broken line in the flowchart of FIG. 7, after the lens interval adjustment (steps 704 and 705) and the lens rotation angle adjustment (steps 706 and 707), the lens axis adjustment (step) is performed again. 702 and 703) may be required.
In particular, since the adjustment of the lens rotation angle is a cancellation of the asymmetry of the lens, it has a close relationship with the adjustment of the axis of the lens that is also adjusting to increase the symmetry. For this reason, it may be necessary to make three adjustment cycles.

As a fixing means after the achievement of the performance in step 709, the ring-shaped fixing screw 14b is shown in FIG. 2, but the illustration is omitted in FIGS.
For example, in FIG. 4, it is conceivable to fix the rotation of the ring-shaped taper screw 19a with a small set screw. Similarly, the rotation of the worm 31 may be fixed in FIG. In addition, there are fixing means such as pouring resin into the gaps between the second lens 12 and the lens holder 15 and the lens barrel 16 to cure.

It is a block diagram which shows the laser processing apparatus by Embodiment 1 of this invention. It is sectional drawing which shows the condensing lens apparatus by Embodiment 1 of this invention. It is a plane sectional view showing the circumference of the 2nd lens of the condensing lens device by Embodiment 1 of this invention. It is a fragmentary sectional view which shows the other Example of the condensing lens apparatus by Embodiment 1 of this invention. It is a figure for demonstrating correction | amendment of the field curvature of the condensing lens apparatus by Embodiment 1 of this invention, and the field curvature by a lens space | interval adjustment mechanism. It is a partial plane sectional view which shows the condensing lens apparatus by Embodiment 2 of this invention. It is a flowchart which shows the adjustment method of the condensing lens apparatus by Embodiment 3 of this invention.

Explanation of symbols

1 laser oscillator, 2 laser beam, 3a, 3b galvanometer mirror,
4a, 4b Galvano scanner, 5 workpiece, 6 scanable area,
10 condensing lens device, 11 first lens, 12 second lens,
13 laser beam, 15 lens holder, 16 lens barrel, 17 micrometer,
18, 18a Spring, 19 Lens interval adjustment mechanism, 21 Laser beam group,
22 condensing point group, 23 image plane of condensing lens device, 24 work piece, 31 worm,
32 Worm wheel.

Claims (2)

A lens axis composed of a plurality of lenses for condensing a laser beam scanned by a beam scanning mechanism and capable of adjusting the position by translating at least one lens in a two-dimensional direction orthogonal to the optical axis An adjusting mechanism, a method for adjusting a condensing lens device provided with a lens interval adjusting mechanism capable of adjusting the position by translation in the optical axis direction,
The position of the at least one lens is adjusted in a two-dimensional direction orthogonal to the optical axis so that the beam intensity distribution is symmetric in the upper, lower, left, and right areas of the area in the scanable area of the workpiece. Steps,
The step of adjusting the position of the at least one lens in the optical axis direction so as to reduce the difference in height in the optical axis direction of the condensing point group of the beam in the scannable area. A method for adjusting a condensing lens device. A lens axis composed of a plurality of lenses for condensing a laser beam scanned by a beam scanning mechanism and capable of adjusting the position by translating at least one lens in a two-dimensional direction orthogonal to the optical axis This is a method for adjusting a condensing lens device having an adjustment mechanism, a lens interval adjustment mechanism that can be moved in parallel in the optical axis direction, and a lens rotation angle adjustment mechanism that can be rotated around the optical axis. And
The position of the at least one lens is adjusted in a two-dimensional direction orthogonal to the optical axis so that the beam intensity distribution is symmetric in the upper, lower, left, and right areas of the area in the scanable area of the workpiece. Steps,
Adjusting the position of the at least one lens in the optical axis direction so as to reduce a difference in height in the optical axis direction of a collection point group of beams in a scannable area;
The at least one lens includes a step of adjusting an angle about an optical axis as a rotation axis so that a beam intensity distribution is symmetric in the upper, lower, left, and right areas of the area in a scannable area. A method for adjusting a condensing lens device.

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