KR20200063335A - optical beam irradiation apparatus of 3D printer - Google Patents

Abstract

The present invention relates to an optical beam irradiation apparatus of a 3D printer for irradiating an optical beam to a mold material to mold. The optical beam irradiation apparatus of a 3D printer comprises: a main collimating lens to convert light output from a laser light source into parallel light; a beam size control unit to control a size of a sectional area of optical beam by inputting light output from the main collimating lens to a main light output path; a beam scan unit to scan the light performed by the beam size control unit to be irradiated to a preset target position. The beam size control unit comprises: a diffusion lens having a first focus distance of a negative value to diffuse light entering in the main optical output path; at least one block lens having a focus distance of a positive value to convert the diffused light in the main optical output path by the diffusion lens into the parallel light; and an input/output driving unit to drive the diffusion lens and the block lens to input/output. A distance between the diffusion lens and the block lens on the main optical output path is a sum of the focus distance of the block lens and the first focus distance.

Description

Optical beam irradiation apparatus of 3D printer

The present invention relates to a light irradiation device of a 3D printer, and more particularly, to a light irradiation device of a 3D printer that supports variable size of a light beam to support stereoscopic molding.

3D printer refers to a device capable of forming a three-dimensional shape to be formed by a printing technique.

Recently, a so-called 3D printing method has emerged, in which designers and designers of products generate 3D modeling data using CAD or CAM, and produce prototypes of 3D shape using the generated data. Is used in a wide variety of fields, including industry, life, and medicine.

The basic principle of a typical 3D printer is to create 3D objects by stacking thin 2D layers.

That is, in the 3D printer method, a laser beam is injected into a photocurable resin to form a laser beam using a functional polymer or metal powder instead of the photocurable resin in SLA (StereoLithography Apparatus) using the principle that the injected part is cured. There are SLS (Selective Laser Sintering) using the principle of molding by molding the functional polymer or metal powder by injection, IM (Inkjet modeling) using thermoplastic resin, and 3D (3 Dimension Printing) using lime powder.

The conventional SLA method is disclosed in U.S. Patent 4,575,330 as a method using a photocurable resin.

On the other hand, when molding while irradiating the photocurable resin with the same beam size, the forming speed is affected by the beam size.

That is, when the beam size is small, the molding precision can be increased, but the molding speed is lowered, and when the beam size is large, the molding precision is lowered, but the molding speed can be improved.

Therefore, there is a demand for a light irradiation method capable of increasing both molding precision and molding speed.

On the other hand, when adjusting the size of the light beam by moving the lens in and out on the optical path, it is difficult to variously adjust the size of the light beam when the light generated through the entered lens is not parallel light.

The present invention was devised to solve the above requirements, so that the size of the light beam can be reduced in a molded part that requires high precision, and the size of a light beam can be enlarged in a molded part that does not require high precision. An object of the present invention is to provide a light irradiation apparatus of a 3D printer that supports to adjust the cross-sectional size of the balanced beam while maintaining the state of the balanced beam.

In order to achieve the above object, a 3D printer light irradiation device according to the present invention includes a laser light source for emitting laser light in a laser irradiation device of a 3D printer that can be formed by irradiating a laser to a molding material; A main collimating lens that converts light emitted from the laser light source into parallel light; A beam size adjusting unit for adjusting the cross-sectional area of the light beam while entering and exiting the main light exit path of light emitted through the main collimating lens; And a beam scanning unit configured to scan the light traveling through the beam size adjusting unit to be irradiated to a set target position, and the beam size adjusting unit is inside and outside the main light exit path on the path of light traveling through the main collimating lens. A diffusion lens having a first focal length of a negative value while diffusing the light traveling through the main collimating lens in a state in which it enters and exits the main light exit path; It is installed to enter and exit the main light exit path on the progress path of the light passing through the diffusion lens, and converts the light diffused through the diffusion lens into parallel light while entering the main light exit path. At least one convex lens having a focal length; And an input/output driving unit that drives the diffused lens and the convex lens to enter and exit the main light exit path. It is intended to have a distance corresponding to the sum of the first focal lengths.

Preferably, the beam size adjusting unit is configured to expand the beam diameter of light traveling through the main collimating lens by a first convex lens and the beam diameter of light traveling through the main collimating lens by three times. A second convex lens that can be applied.

In addition, the input and output driving unit supports the diffusion lens and the convex lens, respectively, and a holder having a support ring and a movable bar extending from the support ring; A driving motor coupled to the end of the movable bar to rotate the center of the support ring to enter and exit the main light exit path; When the movable bar reaches the entry position in the main light exit path in a housing that rotatably supports the rotating shaft of the driving motor, a first hyper-movement stopper that interferes with the movable bar to prevent over-movement; and the movable bar is the main When reaching the standby position outside the light exit path, it is preferable to further include a second overtravel stopper that interferes with the movable bar to prevent overtravel.

According to the light irradiation apparatus of the 3D printer according to the present invention, while maintaining the parallel light, it is possible to adjust and provide the size of the light beam to be irradiated to the area to be molded, thereby changing the size and speed of the light beam while changing the size of the light beam to the area to be molded. Provides adjustable benefits.

1 is a view showing a light irradiation device of a 3D printer according to the present invention,
2 is a view schematically showing the beam size adjusting unit of FIG. 1,
3 is a view for explaining the arrangement structure of the lens of FIG. 2,
4 is a view showing a light beam in a state outside the main light emission path of the beam size adjusting unit of FIG. 2 to explain the process of changing the size of the light beam,
FIG. 5 is a view showing a change in a light beam in a state in which a diffusing lens and a first convex lens enter the main light emission path of the beam size adjusting unit of FIG. 2 to explain the process of changing the size of the light beam,
FIG. 6 is a view showing a change in a light beam in a state in which a diffusing lens and a second convex lens enter the main light emission path of the beam size adjusting unit of FIG. 2 to explain the process of changing the size of the light beam,
7 is a view showing the structure of the entry and exit of the beam size adjustment unit,
8 is a view for explaining a light irradiation pattern for molding using a light irradiation device,
9 is a view showing an example of a beam scan unit of FIG. 1.

Hereinafter, a light irradiation apparatus of a 3D printer according to a preferred embodiment of the present invention will be described in more detail with reference to the accompanying drawings.

1 is a view showing a light irradiation device of a 3D printer according to the present invention.

Referring to FIG. 1, the light irradiation apparatus 100 according to the present invention includes a laser light source 110, a main collimating lens 120, a beam size adjusting unit 200, and a beam scanning unit 140.

The laser light source 110 emits laser light.

The main collimating lens 120 converts the light emitted from the laser light source into a parallel beam.

The beam size adjusting unit 200 is configured to be able to adjust the cross-sectional area of the light beam as it enters the main light exit path 120a of light emitted through the main collimating lens 120 after being emitted from the laser light source 110.

The detailed structure of the beam size adjusting unit 200 will be described later.

The beam scan unit 140 adjusts the light traveling direction so that the light traveling through the beam size adjusting unit 200 is irradiated to a set target position.

The beam scan unit 140 may be constructed in a conventional structure, and an irradiation direction with respect to the first direction based on the forming surface 152 for light traveling through the beam size adjusting unit 200 as illustrated in FIG. 9 The first direction adjuster 143 for adjusting and adjusting the angle of the first reflector 141, and the second reflector for the second direction orthogonal to the first direction with respect to the light passing through the first reflector 141 It may be constructed as a second direction adjuster 145 to adjust by adjusting the angle of (142).

Reference numeral 147 is an f-theta (f-θ) lens.

The molding unit 150 is configured to be formed by a laser beam irradiated while supplying a molding material.

In the illustrated example, as the molding material, the base platform 153 provided to be raised and lowered in the water tank 151 in which the photocurable resin is stored is gradually lowered through the elevating rod 154 to the resin cured by the irradiated laser beam. It can be molded by.

Of course, the molding part 150 may be applied to the molding part of the SLS method in addition to the illustrated method.

Hereinafter, the beam size adjusting unit 200 will be described with reference to FIG. 2.

The beam size adjusting unit 200 includes a diffusion lens 210, a first convex lens 220, a second convex lens 220, and an input/output driving unit 250.

The diffusion lens 210 is installed to enter and exit the main light exit path 120a on the progress path of the light passing through the main collimating lens 120.

The diffusing lens 210 is a concave lens that diffuses light traveling through the main collimating lens 120 in the state of entering the main light exit path 120a and has a negative first focal length f1.

The first convex lens 220 is installed to enter and exit the main light exit path 120a on the path of light traveling through the diffusion lens 210.

The first convex lens 220 converts light diffused through the diffusion lens 210 into parallel light while entering the main light exit path 120a, and has a positive focal length f2.

The second convex lens 230 is installed to enter and exit the main light exit path 120a on the path of light traveling through the diffusion lens 210.

The second convex lens 230 converts light diffused through the diffusion lens 210 into parallel light while entering the main light exit path 120a and has a positive focal length f3.

In this optical arrangement structure, the first convex lens 220 has a distance between the first convex lens and the diffusion lens 210 entering the main light exit path 120a in the state in which the main light exit path 120a has entered. It is installed to have a distance corresponding to the sum of the first focal length f1 from the focal length f2 of 220.

In addition, the distance between the second convex lens 230 and the diffusing lens 210 entering the main light exit path 120a in the state in which the main light exit path 120a has entered is the second convex lens 230. It is installed to have a distance corresponding to the sum of the first focal length f1 from the focal length f3 of.

Preferably, the first convex lens 220 is arranged to expand the beam diameter of light traveling through the main collimating lens 120 to twice, and the second convex lens 230 is the main collimating lens 120 It is arranged to be able to expand the beam diameter of light traveling through the triple.

The arrangement structure of the first convex lens 220 and the second convex lens 230 will be described with reference to FIG. 3.

First, for convenience of explanation, the case where the f1 value is -100mm will be described as an example.

The magnification of the first convex lens 220 is -f2/f1, and in order to double the beam diameter of light traveling through the main collimating lens 120 and the diffusing lens 210, the first convex lens 220 The focal length f2 is 200 mm.

Accordingly, the separation distance D2 between the first convex lens 220 and the diffusion lens 210 is the sum of the first focal length f1 from the focal length f2 of the first convex lens 220 (200 mm-). 100mm = 100mm) corresponding to 100mm may be arranged.

In addition, the magnification of the second convex lens 230 is -f3/f1, and the second convex lens 230 is used to expand the beam diameter of light traveling through the main collimating lens 120 and the diffusing lens 210 three times. ) The focal length f2 is 300mm.

In this case, the separation distance D3 between the second convex lens 230 and the diffusion lens 210 is the sum of the first focal length f1 from the focal length f3 of the second convex lens 230 (300 mm) -100mm = 200mm) corresponding to 200mm can be arranged.

According to this optical arrangement structure, as shown in FIG. 4, the diffusion lens 210, the first convex lens 220 and the second convex lens 230 are outside the light beam traveling path of the main light exit path 120a. When in the standby position, the case where the light emitted through the main collimating lens 120 has a beam diameter of Wo corresponds to one magnification.

In addition, in order to expand the diameter of the light beam twice, only the diffusion lens 210 and the first convex lens 220 need to be entered into the main light exit path 120a as shown in FIG. 5.

In addition, in order to expand the diameter of the light beam three times, as shown in FIG. 6, only the diffusion lens 210 and the second convex lens 230 need to enter the main light exit path 120a.

On the other hand, unlike the illustrated example, the diameter of the light beam can be constructed to extend 1.5 times, and in this case, a convex lens corresponding to the above-described condition may be additionally disposed.

The entry/exit driving unit 250 is configured to drive the diffusion lens 210 and each of the first and second convex lenses 220 and 230 to enter and exit the main light exit path 120a, and refer to FIG. 7 together. Explain.

The entry/exit driving unit 250 includes a holder 251, a housing 252, a motor 254, and first and second anti-movement stoppers 261 and 262.

The holder 251 is a support ring 251a formed to receive and support the edges of the diffusion lens 210, the first and second convex lenses 220, 230, and a bar at one side of the support ring 251a. It is formed to have a movable bar 251b extended in the form.

The driving motor 254 is mounted on the housing 252, and the end of the movable bar 251b is coupled to the rotating shaft 254a to rotate the center of the support ring 251a into and out of the main light exit path 120a. Order.

Here, the housing 252 accommodates the driving motor 254, but allows rotation of the movable bar 251b, and may be formed such that the first and second anti-movement stoppers 261 and 262 described later can be installed. .

The housing 252 is fixedly installed to satisfy the conditions described above in an enclosure (not shown) that accommodates the elements of the beam size adjusting unit 200.

The first over-movement stopper 261 when the movable bar 251b reaches the entry position in the main light exit path 120a in the housing 251 rotatably supporting the rotating shaft 254a of the driving motor 254 It is installed to protrude in the housing 252 to enter the rotational path of the movable bar 251b so as to prevent subsequent movement by interfering with the movable bar 251b to prevent over-moving.

In addition, the second over-movement stopper 262 is installed to protrude in the housing 252 to interfere with the movable bar to prevent over-movement when the movable bar 251b reaches a standby position outside the main light exit path 120a. have.

Meanwhile, an example of a molding process using the beam size adjusting unit 200 will be described with reference to FIG. 8.

When the region 152 to be formed is a rectangular region illustrated in FIG. 4, the diffusion lens 210, the first and second convex lenses 220 and 230 are main light exit paths of the portion corresponding to the contour 161. The light beam is irradiated with the light beam 161a at a magnification of 1 to make it into a standby state that does not enter (120a), and the inner portion 163 of the contour 161 is irrelevant to precision, so the size of the light beam is enlarged (163a) ).

Here, the inner portion 163 of the contour 161 is one of the diffusion lens 210 and the first and second convex lenses 220 and 230 to enter the main light exit path 120a, which is 2 times or 3 times. The light beam 161a enlarged at a magnification may be processed to irradiate light.

According to the light irradiation apparatus of the 3D printer described above, it is possible to adjust and provide the size of the light beam to be irradiated to the area to be molded while maintaining parallel light, thereby changing the size and speed of the light beam while changing the size of the light beam to the area to be molded. Provides adjustable benefits.

110: laser light source 120: main collimating lens
140: beam scanning unit 150: forming unit
200: beam size adjustment unit

Claims (5)

In the laser irradiation apparatus of a 3D printer that can be formed by irradiating a laser to the molding material,
A laser light source that emits laser light;
A main collimating lens that converts light emitted from the laser light source into parallel light;
A beam size adjusting unit that adjusts the cross-sectional area of the light beam while entering and exiting the main light exit path of light emitted through the main collimating lens;
And a beam scanning unit configured to scan light traveling through the beam size adjusting unit to be irradiated to a set target position.
The beam size adjustment unit
It is installed to enter and exit the main light exit path on the progress path of the light going through the main collimating lens, and diffuses the light passing through the main collimating lens while entering the main light exit path and has a negative value. A diffusion lens having a first focal length of;
It is installed to enter and exit the main light exit path on the progress path of the light passing through the diffusion lens, and converts light diffused through the diffusion lens into parallel light while entering the main light exit path, and has a positive value. At least one convex lens having a focal length;
It is provided with; and the input and output driving unit to drive in and out of the main light exit path of the diffusion lens and the convex lens.
The distance between the diffusion lens and the convex lens on the main light exit path is a laser light irradiation of a 3D printer, characterized in that it has a distance corresponding to the sum of the first focal length from the focal length of the convex lens. Device. According to claim 1, The beam size adjustment unit
A laser irradiation device of a 3D printer, characterized in that a first convex lens capable of expanding the beam diameter of light traveling through the main collimating lens is doubled. The method of claim 2, wherein the beam size adjustment unit
A laser light irradiation apparatus of a 3D printer, characterized in that a second convex lens capable of expanding the beam diameter of light traveling through the main collimating lens is tripled. The method according to claim 1, wherein the entry and exit driving unit
A holder having a support ring supporting each of the diffusion lens and the convex lens, and a movable bar extending from the support ring;
A driving motor coupled to the end of the movable bar to rotate the center of the support ring to enter and exit the main light exit path;
It characterized in that it comprises a first movement prevention stopper that interferes with the movable bar to prevent over-movement when the movable bar reaches the entry position in the main light exit path in a housing rotatably supporting the rotating shaft of the driving motor. 3D printer laser light irradiation device. The method of claim 4, wherein the housing
And a second over-movement stopper for interfering with the movable bar to prevent over-moving when the movable bar reaches a standby position outside the main light exit path.

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