KR101657700B1

KR101657700B1 - optical beam irradiation apparatus of 3D printer

Info

Publication number: KR101657700B1
Application number: KR1020150076696A
Authority: KR
Inventors: 박종복; 한수욱; 임정운; 김윤현; 임영은; 김종섭
Original assignee: 한국광기술원
Priority date: 2015-05-29
Filing date: 2015-05-29
Publication date: 2016-09-20

Abstract

The present invention relates to a laser light irradiating apparatus for a 3D printer, and more particularly, to a laser light irradiating apparatus of a 3D printer, which comprises a laser light source for emitting laser light so as to be formed by irradiating laser light to a molding material, a main collimating lens for converting light emitted from the laser light source into parallel light A beam size adjusting unit provided on a light output path of light emitted through the main collimating lens to adjust a cross sectional area size of the light beam, and a beam scanning unit scanning the light traveling through the beam size adjusting unit to a predetermined target position Respectively. According to such a light irradiation apparatus of the 3D printer, the contour portion of the area to be formed can be reduced and the size of the light beam is reduced, and the contour area can be enlarged and the size of the light beam can be enlarged so as to be formed while being irradiated, Thereby providing an advantage that the molding speed can be improved.

Description

[0001] The present invention relates to an optical beam irradiation apparatus of a 3D printer,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a light irradiation apparatus for a 3D printer, and more particularly, to a light irradiation apparatus for a 3D printer capable of varying the size of a light beam to be three-

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

In recent years, a so-called three-dimensional printing method has been introduced in which product designers and designers generate 3D modeling data using CAD or CAM, and produce prototypes of three-dimensional shapes using the generated data. In various fields such as industry, life, and medicine.

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

That is, in the 3D printer method, SLA (Stereolithography Apparatus) using the principle that the scanned portion is cured by injecting a laser beam to the photo-curable resin and a laser beam using a functional polymer or metal powder instead of the photo- SLS (Selective Laser Sintering), IM (Inkjet modeling) using a thermoplastic resin, and 3DP (3D Dimension Printing) using a lime powder are the principles of forming a functional polymer or a metal powder by injection by injection.

The conventional SLA method is disclosed in U.S. Patent No. 4,575,330 by using a photo-curable resin.

On the other hand, when molding the photocurable resin while irradiating the same beam size, the shaping speed is influenced by the beam size.

That is, if the beam size is small, the forming precision can be increased, but the forming speed is low, and if the beam size is large, the forming accuracy is lowered, but the forming speed can be improved.

Therefore, a light irradiation method capable of increasing both the molding precision and the molding speed is required.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a method of forming a light beam, which can reduce the size of a light beam in a molding part requiring high precision, It is an object of the present invention to provide a light irradiation apparatus for a 3D printer.

According to an aspect of the present invention, there is provided a laser irradiation apparatus for a 3D printer, the laser irradiation apparatus comprising: a laser light source for emitting laser light; A main collimating lens for converting light emitted from the laser light source into parallel light; A beam size adjusting unit installed on a light output path of light emitted through the main collimating lens to adjust a size of a sectional area of the light beam; And a beam scanning unit for scanning the light traveling through the beam size adjusting unit to be irradiated to a predetermined target position.

According to an aspect of the present invention, the beam size adjusting unit includes: a first convex lens disposed in front of the main collimating lens and having a focal length variable according to an outer diameter of a beam incident on the optical axis; And a second collimating lens which is provided so as to be able to enter and exit the optical path between the main collimating lens and the first convex lens and enters the optical path between the main collimating lens and the first convex lens, A first retractable lens for reducing an outer diameter of a light beam to be projected; And a forward / backward driving unit that adjusts entry / exit between the main collimating lens and the first convex lens of the first retractable lens.

According to another aspect of the present invention, the beam size adjusting unit includes: a housing capable of receiving parallel light traveling through the main collimating lens through an incident window; A diffusion lens mounted in the housing and diffusing the light incident from the laser light source so as to expand the outer diameter; A subcollimating lens for converting light propagating from the diffusion lens into parallel light in the housing and outputting the parallel light; And a spacing distance adjusting unit coupled to the subcollimating lens to adjust a distance between the subcollimating lens and the diffusing lens to adjust a cross-sectional size of a parallel beam emitted from the subcollimating lens.

Wherein the distance adjustment unit comprises: at least one linear shaft extending in a direction parallel to an optical axis of the diffusion lens in the housing; An advancing / retracting bracket coupled to the linear shaft so as to be retractably engaged with the sub-collimating lens; A linear screw provided in the housing in parallel with the linear shaft so as to be rotated by a motor; And a forward / backward screw portion threadedly coupled to the linear screw, the forward / outward screw portion of which the outside is engaged with the forward / backward bracket so as to be advanced / retreated in accordance with forward and reverse rotation of the linear screw.

According to another aspect of the present invention, there is provided a method of forming a 3D printer including a laser light source for emitting laser light, a main collimating lens for converting light emitted from the laser light source into parallel light, And a beam scanning unit which is provided on the exit path and adjusts the cross sectional area size of the light beam, and a beam scanning unit which scans the light traveling through the beam size adjusting unit to be irradiated to a predetermined target position and irradiates the light- A method of irradiating a photocurable material with a laser beam using an irradiation device, the method comprising: irradiating a contour portion of a region to be formed with a first light beam, the contour region having a beam size whose outer diameter is wider than the first light beam While being irradiated with the second light beam.

According to the light irradiation apparatus of the 3D printer according to the present invention, the contour portion of the area to be molded can be reduced and the size of the light beam can be reduced, It offers the advantage of improving the molding speed without cutting.

1 is a view showing a light irradiation device of a 3D printer according to the present invention,
FIG. 2 is a view showing a first embodiment of the beam size adjusting unit of FIG. 1,
Fig. 3 is a view showing a state in which the first retractable lens of Fig. 2 is deviated from the optical path as compared with Fig. 2,
Fig. 4 is a view for explaining a light irradiation pattern for molding using the light irradiation apparatus of Fig. 1,
5 is a cross-sectional view showing a second embodiment of the beam size adjusting unit of FIG. 1,
FIG. 6 is a diagram showing an example of the beam scanning unit of FIG. 1. FIG.

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

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

1, a 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 130, a beam scanning unit 140, and a forming unit 150, Respectively.

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 130 is disposed on the light output path of the light emitted from the laser light source 110 and then through the main collimating lens 120 to adjust the size of the sectional area of the light beam.

In the illustrated example, the beam size adjusting unit 130 is provided on the light output path of the light traveling through the main collimating lens 120 to adjust the size of the beam.

The detailed structure of the beam size adjusting unit 130 will be described later.

The beam scanning unit 140 adjusts the traveling direction of light so that light traveling through the beam size adjusting unit 130 is directed to a set target position.

As shown in FIG. 6, the beam scanning unit 140 may be configured such that the irradiation direction with respect to the first direction is referred to as a first direction with respect to the shaping surface with respect to light traveling through the beam size adjustment unit 130, A first direction adjuster 143 for adjusting the angle of the reflector 141 and a second reflector 142 for a second direction orthogonal to the first direction with respect to light traveling through the first reflector 141, And a second direction adjuster 145 for adjusting and adjusting the angle of the second direction adjuster.

Reference numeral 147 denotes an f-theta lens.

The forming unit 150 is configured such that molding can be performed by a laser beam irradiated while supplying a molding material.

In the illustrated example, the base platform 153, which is raised and lowered in the water tank 151 in which the photocurable resin is stored as a molding material, is gradually lowered through the lifting and lowering rod 154, As shown in Fig.

It is needless to say that the molding part 150 may be formed by an SLS molding part other than the illustrated method.

Hereinafter, the beam size adjusting unit 130 will be described with reference to FIG.

The beam size adjusting unit 130 includes a first convex lens 135 disposed in front of the main collimating lens 120 and having a focal length variable depending on an outer diameter of a beam incident on the optical axis, The first convex lens 133 and the first convex lens 133 are provided so as to be in and out of the optical path between the first convex lens 120 and the first convex lens 135, 135 for regulating the entrance and exit of the inside and outside of the vehicle.

Here, the first retractable lens 133 is configured to reduce the outer diameter of the light beam emitted from the main collimating lens 120 in a state in which the first retractable lens 133 enters the optical path between the main collimating lens 120 and the first convex lens 135 A material having a convex surface is applied.

3, it can be seen that the condition of FIG. 2 is larger than that of FIG. 3 in the beam size formed on the basis of the arbitrary image forming surface 139 at the same distance with respect to the main collimating lens 120 have.

Here, the image-forming surface can be a molding surface on which the molding material of the molding part is exposed.

The advance / retreat drive unit 138 may be a cylinder or other actuator coupled to move the first retractable lens 133 in the direction perpendicular to the path of the light beam.

An example of a process of forming using the beam size adjustment unit 130 will be described with reference to FIG.

4, the portion corresponding to the contour line 161 is formed by the light beam 161a having a reduced size of the light beam by causing the first retractable lens 133 to enter the optical path, And since the inside portion 163 of the contour 161 is irrelevant to the accuracy, the size of the light beam may be irradiated with the enlarged light beam 163a.

Another structure of the beam size adjusting unit will be described with reference to FIG.

5, the beam size adjusting unit 230 includes a housing 231, a diffusion lens 241, a subcollimating lens 243, and a distance adjustment unit 250.

The housing 231 can receive the parallel light traveling from the laser light source 110 through the main collimating lens 120 through the incident window 232 and can be mounted with an element for adjusting the size of the light beam inside And has an internal space and is configured to emit a light beam through an emission window 233.

The incident window 232 is preferably AR coated.

The diffusion lens 241 is a concave lens that is mounted in the housing 231 and diffuses the light incident from the laser light source 110 through the main collimating lens 120 so as to expand the cross-sectional outer diameter.

The subcollimating lens 243 is coupled to the advancing / retracting bracket 261, and converts the light propagating in the housing 231 from the diffusion lens 241 into parallel light.

The spacing distance adjusting unit 250 is coupled with the subcollimating lens 243 to adjust the spacing distance between the subcollimating lens 243 and the diffusing lens 241 to adjust the spacing of the parallel beams emitted from the subcollimating lens 243 Adjust the size.

The spacing distance adjusting unit 250 includes a linear shaft 253, a forward and backward bracket 261, a linear screw 263, a motor 265, and a forward / backward screw portion 267.

The linear shaft 253 is provided in the housing 231 so as to extend in the upper and lower portions in parallel with the optical axis of the diffusion lens 241.

The advancing / retracting bracket 261 is engaged with the upper and lower sides of the subcollimating lens 243 so as to be moved forward and outward along the linear shaft 253.

The linear screw 263 is arranged in parallel with the linear shaft 253 in the housing 231 so as to be rotated by the motor 265.

The forward and backward screw portions 267 are formed in the form of a nut and are screwed to the linear screws 263 and coupled to the forward and backward brackets 261 so as to advance and retreat in accordance with the forward and reverse rotation of the linear screws 263.

Reference numerals 271 and 272 are limit switches provided so as to be able to respectively contact the linear shaft 253 and the advancing screw portion 267 so as to limit the moving distance of the diffusion lens 243, respectively.

The control unit (not shown) of the light irradiation apparatus 100 receives the light scanning pattern data corresponding to the shape to be molded and drives the laser light source 110. As described above, The beam size adjusting unit 130 is adjusted so that the beam size is adjusted according to the inner area, and the beam scanning unit 140 is controlled so that the beam is irradiated in the desired irradiation direction.

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

Claims

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A laser irradiation apparatus of a 3D printer capable of forming a molding material by laser irradiation,
A laser light source for emitting laser light;
A main collimating lens for converting light emitted from the laser light source into parallel light;
A beam size adjusting unit installed on a light output path of light emitted through the main collimating lens to adjust a size of a sectional area of the light beam;
And a beam scanning unit for scanning the light traveling through the beam size adjusting unit to be irradiated to a predetermined target position,
The beam size adjusting unit
A housing capable of receiving parallel light traveling through the main collimating lens through an incident window;
A diffusion lens mounted in the housing and diffusing the light incident from the laser light source so as to expand the outer diameter;
A subcollimating lens for converting light propagating from the diffusion lens into parallel light in the housing and outputting the parallel light;
And a separation distance adjusting unit coupled to the subcollimating lens to adjust a distance between the subcollimating lens and the diffusing lens to adjust a cross-sectional size of a parallel beam emitted from the subcollimating lens,
The distance-
At least one linear shaft extending in a direction parallel to an optical axis of the diffusion lens in the housing;
An advancing / retracting bracket coupled to the linear shaft so as to be retractably engaged with the sub-collimating lens;
A linear screw provided in the housing in parallel with the linear shaft so as to be rotated by a motor;
And a forward / backward threaded portion threadedly coupled to the linear screw and having an outer side engaged with the forward / backward bracket so as to be advanced / retreated in accordance with forward and reverse rotation of the linear screw.