JP3653385B2 - Optical modeling method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical modeling method for modeling a desired resin model by scanning and irradiating a light curable resin such as an ultraviolet curable resin, and in particular, a closed region surrounded by a contour line is increased. The present invention relates to an optical modeling method for modeling with accuracy.
[0002]
[Prior art]
For example, a desired resin model can be formed by scanning the surface of a tank containing an ultraviolet curable resin liquid while turning on / off an ultraviolet laser, and sequentially stacking the cured cured layers by this. Has been tried. Since such a resin model is used as a master model of a product, for example, it is necessary to improve modeling accuracy, interlayer adhesion, modeling efficiency, and the like when modeling.
[0003]
The conventional optical modeling method generates ultraviolet rays from an ultraviolet laser, and accommodates an ultraviolet curable resin liquid while controlling ON / OFF of the ultraviolet laser and the scanning direction of the light beam by an optical system having a galvano mirror and a shutter. Irradiate the surface of the tank. An elevator capable of moving up and down while blocking the ultraviolet laser is provided in the tank, and the resin liquid interposed between the resin liquid surface and the elevator is cured by the ultraviolet laser.
[0004]
In the first stage of the modeling process, the elevator is raised, and the resin liquid interposed between the resin liquid surface and the elevator is cured by an ultraviolet laser to form the first scanning cured layer, The elevator is lowered by one layer, and the second scanning hardened layer is formed on the first scanning hardened layer in the same procedure as the first layer. In the same manner, the scanning hardened layer is sequentially laminated (hereinafter also referred to as deposition). When the final scan hardened layer is formed, the elevator is raised and the model is taken out from the resin liquid. In order to perform proper curing, as shown in FIG. 10, the entire model W is irradiated with ultraviolet rays for a long time using an ultraviolet lamp 50 or the like.
[0005]
Hereinafter, in the present specification, a plane within the same movement pitch of the above-described elevator is referred to as a “contour section”, and this one contour section has a resin according to the three-dimensional shape of the target model W. There are areas where the liquid is cured and areas where the resin liquid is not cured.
[0006]
The ultraviolet beam generated from the ultraviolet laser oscillator is scanned along the scanning direction by the optical system. At this time, in the region where the resin liquid is cured, the ultraviolet laser is turned on (actually the shutter AOM is opened), and the resin liquid is turned on. In the region where curing is not performed, the ultraviolet laser is turned off (actually, the shutter AOM is closed). When the scanning of one scanning line is completed, the optical system is controlled to move by the scanning pitch, and the same scanning is performed again along the scanning direction.
[0007]
When the ultraviolet beam is irradiated into the resin liquid, the light energy is gradually reduced by the resin liquid. Therefore, microscopically, a sharp irradiation region (that is, a scanning hardened layer) is formed. Become.
[0008]
In this way, a scanning hardened layer having a constant cross section is formed. When the scanning hardened layer is sequentially laminated, the lower layer is irradiated with an ultraviolet beam when forming the upper scanning hardened layer. The light intensity, that is, the curing depth in the contoured section is controlled to be larger than the lamination thickness so as to enhance the adhesion between the layers.
[0009]
[Problems to be solved by the invention]
By the way, when the shape of the scanning hardened layer in one contour section is a closed region surrounded by the contour line as shown in FIG. 11, the conventional modeling method first recognizes the contour line OL shown in FIG. In addition, as shown in FIG. 12, scanning is performed in parallel along one edge of the contour line starting from the point P0, and scanning is performed up to the end point P1 of the scanning line. The same scanning is performed again from the starting point P2 along the next scanning line.
[0010]
Such a scanning method is referred to as raster scanning. However, in the conventional optical modeling method using such raster scanning, since the ultraviolet beam is microscopically a spot-like light beam, The cured region at the end point, that is, the edges OL2 and OL3 shown in FIG. 12, does not have a shape along the contour line, and there is a problem when a high-accuracy model is formed.
[0011]
Therefore, when modeling a three-dimensional model with high accuracy, it is necessary to reduce the spot diameter of the ultraviolet beam and further reduce the scanning pitch, and the modeling time becomes longer, or position control at the start point and the end point is performed. There was a problem of becoming more severe.
[0012]
The present invention has been made in view of such problems of the prior art, and an object thereof is to form a closed region surrounded by a contour line with high accuracy.
[0013]
[Means for Solving the Problems]
Optical fabricating method of the present invention, applied to the surface of the photocurable resin liquid contained in the photocurable resin liquid tank, a scan pattern based on the scan cured layer information, a light beam at the irradiated surface of the radius of a certain repeated that by curing the photocurable resin liquid to form a scanning hardened layer, scanning the hard layer which is the form is lowered from the surface of the photocurable resin liquid to form the next scan cured layer a optical fabricating method for shaping a predetermined solid resin model by, in the formation of each scan hardened layer, the scanning cured layer information, extracted from the three-dimensional information of the three-dimensional resin model to be shaped, the scanning cured layer Based on the information, information about the first contour line is extracted , information about the second contour line on the inner side by a distance corresponding to the radius from the first contour line is calculated, and the first contour line is calculated. A third inward from the line by a distance corresponding to three times the radius. Calculating information about the contour lines, the light beam to form the outline of vector scanning to scan cured layer so that the irradiation surface center of the light beam is moved along the second contour, from the start point to the end point Raster scanning, in which linear scanning is repeated while sequentially shifting the start point and end point so that the scan lines are parallel to each other, is such that the center of the irradiation surface of the light beam is positioned on the third contour line at the start point and end point executed, the curing the closed region surrounded by the contour, the After shaping the solid resin model, make a final cured by irradiation with light in the whole of the three-dimensional resin model.
[ 0014 ]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, the configuration of an optical modeling apparatus according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing a basic configuration of an optical modeling apparatus according to an embodiment of the present invention.
[ 0015 ]
The optical modeling apparatus according to the present embodiment has a photocurable resin liquid tank 2, and the photocurable resin liquid 1 accommodated in the tank is cured by addition polymerization by irradiation with light. Material. For example, vinyl monomers such as styrene, methyl methacrylate, and vinyl acetate can be polymerized by light irradiation in the absence of a photopolymerization initiator or in the presence of a sensitizer or dye that absorbs ultraviolet rays. cause.
[ 0016 ]
However, the kind of the photocurable resin liquid 1 used in the present invention is not particularly limited as long as it is a resin that is liquid when uncured and is solidified by curing. Moreover, it does not specifically limit about the light LB to irradiate, What is necessary is just to select the light according to the photocurable resin 1 used other than an ultraviolet-ray.
[ 0017 ]
In the photocurable resin liquid tank 2, there is provided an elevator 4a having a pedestal on which the cured resin is placed while blocking the light beam. The elevator 4a is moved by the elevator 4b to the photocurable resin liquid tank. 2 can be moved up and down. The elevator 4b has a function of moving the elevator 4a up and down mechanically and a control function for controlling the lifting operation. The command signal for the elevator 4b is given from the general control unit 5a of the control unit 5, but the general control unit 5a commands the elevator 4b based on information to or from the optical scanning unit 3. Output a signal.
[ 0018 ]
For example, when it is detected from the optical scanning means 3 that the scanning of one contour section has been completed, a command signal is output from the general control unit 5a to the elevator 4b in order to shift to the next contour section scanning. As a result, the elevator 4b lowers the elevator 4a by a predetermined pitch (that is, the pitch becomes the stacking thickness T in the contour section).
[ 0019 ]
On the other hand, the optical scanning unit 3 according to the present embodiment scans a laser oscillator 3a that generates a light beam such as an ultraviolet laser, and the light beam generated by the laser oscillator 3a according to a predetermined locus on the surface of the photocurable resin liquid. And an optical system controller 3c for controlling the optical system 3b. The optical system 3b is provided with, for example, a shutter device (AOM) for passing / blocking the light beam, a voltage applicator for changing the direction of the light beam, a galvanometer mirror, and the like. Has a function of changing the optical path, changing the optical path, controlling the scanning speed of the light beam, and the like. A command signal related to the optical scanning condition corresponding to the previously taught locus is output from the optical system controller 3c to the optical system 3b.
[ 0020 ]
The operation of the optical scanning unit 3 in the present invention is basically based on basic trajectory data input in advance to the general control unit 5a, but a three-dimensional modeling information storage unit 5b, a scanning hardened layer information extraction unit 5c, which will be described later, A command signal is output to the optical system controller 3c via the contour detection unit 5d, contour hardening information extraction unit 5e, and inner area information extraction unit 5f, and the detailed optical scanning conditions are changed.
[ 0021 ]
The control unit 5 according to the present embodiment has a general control unit 5a that controls the elevation unit 4 and the optical scanning unit 3 while correlating them with each other based on data input in advance according to a target resin model. doing. In addition to the general control unit 5a, a three-dimensional modeling information storage unit 5b, a scanning hardened layer information extraction unit 5c, a contour line detection unit 5d, a contour hardening information extraction unit 5e, and an inner area information extraction unit 5f are provided.
[ 0022 ]
In the present embodiment, the information processing apparatuses such as the elevator 4b, the optical system controller 3c, and the control means 5 are shown in FIG. 1 as specific examples configured separately from each other. Of course, the information processing apparatus may be configured by combining these in any combination as long as the functions described above are provided.
[ 0023 ]
Next, each processing procedure in the 3D modeling information storage unit 5b, the scanning hardened layer information extraction unit 5c, the contour line detection unit 5d, the contour hardening information extraction unit 5e, and the inner area information extraction unit 5f according to the present embodiment will be described. In order to facilitate understanding of the basic concept of this processing procedure, a specific example of modeling a modeling region surrounded by a contour line within a certain contour section will be described as shown in FIG.
[ 0024 ]
First, the three-dimensional modeling information storage unit 5b is a memory in which information on the three-dimensional shape of the model W to be modeled is stored, and all the information on the three-dimensional shape of the model W, or at least all of the modeling region surrounded by a contour line Information on the three-dimensional shape of the contour section is stored.
[ 0025 ]
In the scanning hardening layer information extraction part 5c, only the information regarding the scanning hardening layer which is a modeling area | region in a certain contour plane is extracted among the three-dimensional information memorize | stored in the three-dimensional modeling information storage part 5b. That is, the general control unit 5a discriminates a cured region and a non-cured region in one contour section, and thereby controls ON / OFF of light in the optical system. In the scanning cured layer information extraction unit 5c, Only information related to the curing region is selected and read out, and this is used as basic information for the following modeling method.
[ 0026 ]
The contour detection unit 5d reads information on only the hardened region extracted by the scanning hardened layer information extraction unit 5c, and recognizes the contour OL of the hardened region in the same contour section based on this information.
[ 0027 ]
Contour hardening information extraction unit 5e, in addition to the original contour line OL detected by the contour detecting unit 5d, as shown in FIG. 2, spaced inwardly of the area and close the original contour line OL distance r ₁ Another contour line OL _A is calculated and obtained. This other contour line OL _A constitutes the center line of vector scanning along the contour line described later. Therefore, the distance r ₁ is (strictly radius hardening circle by ultraviolet beam) radius of the ultraviolet beam LB to set equal to.
[ 0028 ]
Further, in the inner area information extracting unit 5f, as shown in FIG. 2, in addition to the original contour OL detected by the contour detecting unit 5d and another contour OL _A obtained by the contour hardening information extracting unit 5e. Further, another contour line OL _B separated from the original contour line OL by a distance r ₂ inside the closed region is calculated and obtained. This further contour line OL _B constitutes the start point, end point or center line of the raster scan in the closed region described later. Therefore, the distance r ₂ is the radius of the ultraviolet beam LB (strictly radius hardening circle by ultraviolet beam) to set the distance equal to three times the.
[ 0029 ]
Note that the contour line information obtained by the contour hardening information extraction unit 5e is output to the optical system controller 3c, and the scanning of the light LB based on this information is vector scanning along the contour line. That is, as shown in FIG. 3, the start point / end point position and the scanning direction are not limited at all, but the scanning is performed by tracing the contour line.
[ 0030 ]
On the other hand, information related to the closed area obtained by the inner area information extracting unit 5f is also output to the optical system controller 3c. Scanning of the light LB based on this information is performed in the same direction along a certain contour line (single This means so-called raster scanning, which includes both one-way scanning and reciprocating scanning.
[ 0031 ]
Next, the operation will be described.
2 to 4 are plan views showing a modeling method according to this embodiment, and FIG. 5 is a flowchart showing a processing procedure in the control means of the embodiment.
In the conventional optical modeling method, as shown in FIG. 12, the entire closed region is raster scanned, but in this embodiment, the contour line is vector scanning, and the inner region of the contour line is raster scanning. In particular, in the embodiment shown in FIGS. 2 to 4, the center line of vector scanning is set to another contour line OL _A that is offset from the original contour line OL by a distance r ₁ . In addition, the start point and end point for raster scanning are offset by a distance r ₂ inside the original contour line OL.
[ 0032 ]
First, a light beam LB having a wavelength suitable for curing the photocurable resin liquid 1 is generated by the optical scanning means 3a, 3b, 3c, and the photocurable resin liquid 1 contained in the photocurable resin liquid tank 2 is generated. Is scanned with the light beam LB. When scanning on one contour section is completed, the cured resin 51 generated by the irradiation of the light beam LB is moved up and down by the lifting and lowering means 4a and 4b, and the scanning and hardening layer 51 is sequentially laminated by repeating such a procedure. To do.
[ 0033 ]
At this time, first, scanning hardening formed by scanning and irradiating the light beam LB without operating the elevator 4a from the three-dimensional modeling information storage unit 5b storing at least a part of the three-dimensional modeling information to be three-dimensional modeled. Information regarding the layer 51 is extracted by the scanning hardened layer information extraction unit 5c. At the same time, the offset amounts r ₁ and r ₂ are read (steps 1 and 2).
[ 0034 ]
Next, after detecting the contour position OL of the scanning hardened layer 51 by the contour detecting unit 5d based on the scanning hardened layer information obtained from the scanning hardened layer information extracting unit 5c, the contour detecting unit 5d obtains the contour line position OL. respect are outline position OL, it is calculated by the contour hardening information extractor 5e location OL _a of the inner distance r ₁ to a predetermined as the locus information (step 3, FIG. 2).
This trajectory information is output to the optical system controller 3c (step 6), and vector scanning along the above-described contour line is executed (step 7, FIG. 3), so that the spot diameter and scanning pitch of the light beam are reduced. Even without this, the modeling accuracy near the contour line is greatly improved.
[ 0035 ]
On the other hand, the inner region information extractor 5f, relative to the contour line position OL obtained from contour detector 5d, extracts the information only about the inner enclosed area distance r ₂ previously determined (Step 4, FIG. 2 ). This information is output to the optical system controller 3c (step 8), and as a result, raster scanning in the closed region surrounded by the contour line is executed (step 9, FIG. 4).
[ 0036 ]
In particular, by setting r ₁ <r ₂ , the overlapping region between the scanning cured layer by vector scanning and the scanning cured layer by raster scanning along the contour line becomes small, so that the photocurable resin liquid is cured. The shrinkage rate becomes uniform, and the deformation of the obtained model can be suppressed.
[ 0037 ]
In the optical modeling method according to the invention different from the present invention, the above-described embodiment can be variously modified.
For example, with respect to a photocurable resin liquid having a small volume shrinkage when cured by light irradiation, an offset is applied when raster scanning the inner area of the contour line as in the optical modeling method shown in FIGS. Can be omitted. 6 to 9 are plan views showing a reference example of an optical histological molding method.
[ 0038 ]
In the case of the reference example , the center line of the vector scan is set as another outline OL _A offset from the original outline OL by the distance r _1, and the start point and the end point of the raster scan are also set as the other outline OL _A. We are using.
[ 0039 ]
In this reference example , first, it is formed by scanning and irradiating the light beam LB without operating the elevator 4a from the 3D modeling information storage unit 5b storing at least a part of 3D modeling information to be 3D modeled. information about scanning the hardened layer 51 is extracted by scanning the hardened layer information extractor 5c, at the same time, it reads the offset amount r ₁ (see FIG. 6).
[ 0040 ]
Next, after detecting the contour position OL of the scanning hardened layer 51 by the contour detecting unit 5d based on the scanning hardened layer information obtained from the scanning hardened layer information extracting unit 5c, the contour detecting unit 5d obtains the contour line position OL. is relative to the contour line position OL, is calculated by the contour hardening information extractor 5e location OL _a of the inner distance r ₁ to a predetermined as the locus information (see FIG. 7).
The locus information may be output to the optical system controller 3c, it means that the vector scanning along the contour line is performed in the same procedure as implementation embodiment described above (see FIG. 8), beam spot diameter and the scanning Even if the pitch is not reduced, the modeling accuracy near the contour line is greatly improved.
[ 0041 ]
On the other hand, for the inner area information, the trajectory information obtained from the contour hardening information extraction unit 5e is used as it is, and raster scanning is performed within the closed region surrounded by the contour line (see FIG. 9). In this case, the scanning hardening layer cured by vector scanning along the contour line and the scanning hardening layer by raster scanning partially overlap each other. However, when the light shrinkage rate is small, the deformation of the model due to curing does not cause a problem. Therefore, there is an advantage that the time required for calculating the contour line can be shortened.
[ 0042 ]
The embodiments of the present invention, which has been described to facilitate understanding of the present invention and were not described to limit the present invention. Accordingly, respective elements disclosed in the embodiments of the present invention is deemed to also include all design modifications and equivalents belonging to the technical scope of the present invention.
[ 0043 ]
【The invention's effect】
As described above, in the present invention, in forming the modeling region of the contour section layer, the light beam is scanned and cured along the contour line of the modeling region, and the light beam is raster-scanned to perform the inner scanning of the contour line. Since it forms so that a modeling area | region may be hardened, all the edges of the closed area | region shape | molded will follow the scanning direction of a light ray. Therefore, the modeling accuracy in the same contour section can be improved .
[Brief description of the drawings]
FIG. 1 is a block diagram showing a basic configuration of an optical modeling apparatus according to an embodiment of the present invention.
FIG. 2 is a plan view showing a first step of a modeling method according to an embodiment of the present invention.
FIG. 3 is a plan view showing a second step as in FIG. 2;
4 is a plan view showing a third step, similar to FIGS. 2 and 3. FIG.
FIG. 5 is a flowchart showing a processing procedure in the control means of the embodiment.
FIG. 6 is a plan view showing a first step of a modeling method according to a reference example .
FIG. 7 is a plan view showing a second step of the modeling method according to the reference example .
FIG. 8 is a plan view showing a third step of the modeling method according to the reference example .
FIG. 9 is a plan view showing a fourth step of the modeling method according to the reference example .
FIG. 10 is a side view showing a conventional optical modeling method and a step of performing final curing after laminating a scanning cured layer.
FIG. 11 is a plan view showing a first step of a conventional optical modeling method.
FIG. 12 is a plan view showing the second step in the same manner.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Photocurable resin liquid 2 ... Photocurable resin liquid tank 3 ... Optical scanning means 3a ... Laser oscillator 3b ... Optical system 3c ... Optical system controller 4 ... Elevating means 4a ... Elevator 4b ... Elevator 5 ... Control means 5a ... General control unit 5b ... Solid modeling information storage unit 5c ... Scanning hardening layer information extraction unit 5d ... Contour line detection unit 5e ... Contour hardening information extraction unit 5f ... Inner region information extraction unit 6 ... Scanning hardening layer LB ... Ray T ... Lamination thickness

Claims (1)

Curing the surface of the photocurable resin liquid contained in the photocurable resin liquid tank, a scan pattern based on the scan cured layer information, the subsequent light exposure at the irradiated surface of the radius of a certain said photocurable resin liquid forming a scanning hardened layer by, by scanning hard layer which is the form is lowered from the surface of the photocurable resin liquid was repeated to form the next scan cured layer shaping a predetermined solid resin model An optical modeling method to
In forming each scanning hardened layer,
The scanning hardened layer information is extracted from the three-dimensional information of the three-dimensional resin model to be modeled,
Based on the scanning hardened layer information, the information about the first contour line is extracted,
Calculating information about the second contour line on the inner side by a distance corresponding to the radius from the first contour line;
Calculating information about the third contour line on the inner side by a distance corresponding to three times the radius from the first contour line;
The light beam is vector-scanned so that the irradiation surface center of the light beam moves along the second contour line to form the contour of the scanning hardening layer ,
Raster scanning, in which linear scanning from the start point to the end point is repeated while sequentially shifting the start point and end point so that the scan lines are parallel to each other, the center of the irradiation surface of the light beam at the start point and end point is the third contour. Proceed as to be positioned on the line, curing the closed region surrounded by the contour,
An optical modeling method in which, after modeling the three-dimensional resin model, the entire three-dimensional resin model is irradiated with light and finally cured.

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