JPH08318574A - Formation of three-dimensional shape - Google Patents

Abstract

PURPOSE: To shape a three-dimensional shape with high accuracy by laser beam. CONSTITUTION: In a method obtaining a shaped article having a desired three- dimensional shape by irradiating the photo-setting resin soln. 15 stored in a resin soln. tank 12 with laser beam to form a photo-set layer 16 and stacking a plurality of the photo-set layers, the irradiation position of laser beam is measured by a sensor 30 at each time when each layer is shaped and a shaped article having a three-dimensional shape is obtained while the fluctuations of the irradiation position of laser beam are corrected on the basis of the measuring result.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a three-dimensional shape, and more particularly to a method for molding and producing an article having a three-dimensional shape using a photocurable resin which is cured by irradiation with light. It is about.

[0002]

2. Description of the Related Art A method of forming a three-dimensional shape using a photo-curable resin can easily and accurately form a complicated three-dimensional shape without using a molding die or a complicated processing tool. As a method, it is considered to use it for manufacturing various product models and three-dimensional models. Specifically, for example, JP-A-63-141724 and JP-A-2-1 can be used.
There is a method disclosed in Japanese Patent No. 88229.

According to the method disclosed in Japanese Patent Laid-Open No. 63-141724, a photocurable resin liquid is stored in a resin liquid tank and a vertically movable molding table is provided. Once the molding table is deeply submerged below the liquid surface, the molding table is raised to a position slightly below the resin surface, and the molding table has a thickness corresponding to the required photocurable layer thickness. A photocurable resin liquid thin layer is naturally formed. The thin resin liquid layer is scanned and irradiated with laser light modulated by shape data by a scanner to be photo-cured. By repeating the process of raising and lowering the molding table to form the thin resin liquid layer and the step of irradiating the laser beam to form the photocurable layer, the photocurable layer is stacked on the molding table. Thus, a molded product having a desired three-dimensional shape is obtained.

In the method disclosed in Japanese Unexamined Patent Publication No. 2-188229, the bottom of the resin liquid tank is formed of a transparent plate, and the molding table is submerged to the extent that there is a slight gap between the transparent plate and the transparent plate. In this state, the laser light modulated with the shape data is scanned from below the transparent plate into the resin liquid tank by the XY moving device (scanner) and irradiated, and the resin liquid between the transparent plate and the molding table is irradiated. Light cure the thin layer. After the photo-curing layer is formed, if the molding table is raised a little, the photo-curing layer is lifted while being attached to the molding table, and new resin liquid is supplied between the photo-curing layer and the transparent plate. . By repeating such steps, the photocurable layer is stacked on the lower surface of the molding table in a state of being attached thereto.

[0005]

According to the above-mentioned conventional forming method, it is possible to perform accurate exposure with a laser beam in the case of modeling in a short time. However, when modeling for a long time, the laser light source shifts in the oscillation point, the deflection of the support member that supports the laser light source and the optical system due to changes in the ambient temperature, and the temperature change of the scanner itself cause factors such as temperature changes. It is difficult to irradiate laser light accurately.

FIG. 14 shows changes in the irradiation position when nine sensors A to I, which are two-dimensional PSDs (position detecting elements) for measuring the irradiation position, are arranged at nine positions on the resin liquid surface. It is a figure. As is clear from FIG. 14, when the laser light is irradiated for a long time, the irradiation position changes with time at each measurement position due to the above factors. If the irradiation position at the resin forming position is displaced by the irradiation of the laser light for a long time and the resin liquid surface cannot be accurately exposed in this way, the shape changes between the photo-curing layers, and it is impossible to perform molding with high accuracy. The problem arises.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for forming a three-dimensional shape that can be formed with high precision when forming a three-dimensional shape with a light beam.

[0008]

A method for forming a three-dimensional shape according to claim 1 of the present invention, which solves the above-mentioned problems, is to irradiate a photocurable resin liquid stored in a resin liquid tank with a light beam. In the method of forming a photocurable layer and stacking a plurality of the photocurable layers to obtain a modeled article having a desired three-dimensional shape, the irradiation position of the light beam is measured, and the irradiation of the light beam is performed based on the measurement result. It is characterized in that the position variation is corrected.

The basic use device and working process may be the same as in the case of the method for forming various three-dimensional shapes in general as disclosed in the above-mentioned prior art, and the material and formation of the photocurable resin to be used. The three-dimensional shape to be used can be freely selected. For example, as the photocurable resin, a photocurable resin such as urethane, urethane-acrylate, epoxy, or epoxy-acrylate resin is used.

A light beam such as a laser beam is usually used as the irradiation light, and such a light beam is scanned to form a photo-cured layer having a predetermined shape. The energy density of light is the oscillation intensity of the laser oscillator, the configuration of the optical system through which the irradiated light passes, the distance from the oscillator to the resin liquid to be irradiated, the scanning speed when scanning light, the light transmission characteristics of the resin liquid. It depends on such conditions. In the case of a light beam, the energy density changes depending on the beam diameter, and at that focus position,
The beam diameter is the smallest and the energy density is the largest,
The beam diameter increases and the energy density decreases as the distance from the focal point increases.

A method of forming a three-dimensional shape according to claim 2 is
The method according to claim 1, wherein the irradiation position is measured by one or a plurality of fixed sensors. The method for forming a three-dimensional shape according to claim 3 is the method according to claim 2,
The irradiation position is measured by a sensor arranged at substantially the same height as the light source of the light beam. A three-dimensional shape forming method according to a fourth aspect is the method according to the third aspect, wherein the light beam is dispersed and the irradiation position of one spectral beam is measured by a sensor.

A method for forming a three-dimensional shape according to claim 5 is
The method according to claim 1, wherein the irradiation position of the light beam at a predetermined position is recognized by using one or a plurality of moving sensors. The method for forming a three-dimensional shape according to claim 6 is the method according to claim 5, wherein the sensor horizontally positions at least a part of the resin liquid layer formed on the molding table or the photo-cured layer formed previously. It is attached to a sweeping member that is swept by movement.

The method for forming a three-dimensional shape according to claim 7 is
The method according to claim 6, wherein the sweeping member is made stationary at the center and the end of the shaping area of the shaping object. Claim 8
The method for forming a three-dimensional shape according to claim 6 is the method according to claim 6 or 7, wherein the light beam is synchronized with the horizontal movement operation of the sweeping member. A method for forming a three-dimensional shape according to a ninth aspect is the method according to any one of the first to eighth aspects, in which variation correction is performed each time each photo-cured layer is obtained.

The method for forming a three-dimensional shape according to a tenth aspect is the method according to any one of the first to eighth aspects, in which the variation correction is performed every constant time and / or every time a constant layer is obtained. The method for forming a three-dimensional shape according to claim 11 is the method according to any one of claims 1 to 10, wherein the focal length and / or the beam diameter of the light beam is measured, and fluctuations in the focal length of the light beam are further measured. to correct.

A method of forming a three-dimensional shape according to claim 12 is the method according to any one of claims 1 to 11,
The output of the light beam is measured and the output of the light source is controlled.

[0016]

In the method for forming a three-dimensional shape according to claim 1,
When irradiating the light beam, the irradiation position of the light beam is measured by a sensor at a predetermined timing, and the variation of the irradiation position of the light beam is corrected based on the measurement result. Then, a light beam is applied to the resin liquid layer stored in the resin liquid tank to form a photocurable layer, and the photocurable layer is moved up and down to contact the photocurable layer to form the resin liquid layer. By repeating this process, a plurality of photocurable layers are stacked to obtain a molded article having a desired three-dimensional shape. Here, since the irradiation position of the light beam is measured and the fluctuation of the irradiation position is corrected based on the measured position, the irradiation position is less likely to change and the modeling can be performed with high accuracy.

In the method for forming a three-dimensional shape according to the second aspect, since the irradiation position is measured by one or a plurality of fixed sensors, the position of the sensor is surely fixed and the measurement accuracy is improved. Highly accurate modeling is possible. In the method for forming a three-dimensional shape according to claim 3, since the irradiation position is measured by the sensor arranged at substantially the same height as the light source of the light beam, it is affected by the deflection of the supporting member of the optical system. In addition, the problem of adhesion of resin liquid does not occur, the measurement accuracy is further improved, and the deterioration of the sensor performance can be prevented.

In the method for forming a three-dimensional shape according to the fourth aspect, since the light beam is dispersed and the irradiation position of one spectral beam is measured by the sensor, the irradiation position of the light beam being irradiated on the resin liquid layer is determined. You can accurately correct fluctuations in real time,
It is possible to perform modeling with higher accuracy. In the method for forming a three-dimensional shape according to claim 5, since the irradiation position of the light beam at a predetermined position is recognized using one or a plurality of moving sensors, the irradiation position of the moving light beam can be accurately measured in a wide range. Can be measured.

In the method for forming a three-dimensional shape according to the sixth aspect, since the irradiation position is measured by the sensor attached to the sweeping member, the sensor can be moved without using another moving member. In the method for forming a three-dimensional shape according to claim 7, since the sweeping member is stationary at the center and the end of the modeling area of the modeled object, not only the correction of the parallel movement on the resin liquid surface (origin correction), but also the The correction (gain correction) can be performed in consideration of the increment of the shift amount due to the distance from the reference point (end portion), and the variation can be corrected with higher accuracy.

In the method for forming a three-dimensional shape according to the eighth aspect, since the light beam moves in synchronization with the horizontal movement operation of the sweeping member, the fluctuation of any irradiation position during irradiation by a plurality of finite sensors. Can be corrected, and modeling can be performed with higher accuracy. In the method for forming a three-dimensional shape according to the ninth aspect, the variation correction is performed each time each photo-cured layer is obtained, so that the modeling accuracy of each photo-cured layer is further improved.

In the three-dimensional shape forming method according to the tenth aspect, since the variation correction is performed every fixed time and / or each time a fixed layer is obtained, the molding accuracy is further improved. Claim 1
In the method for forming a three-dimensional shape according to the first aspect, for example, the focal length and / or the beam diameter of the light beam are measured at a predetermined timing, and in addition to the correction of the variation of the irradiation position, the variation of the focal length of the light beam is further corrected. Therefore, it is possible to make the cured shape, the degree of curing, etc. of the resin at the time of irradiation of the light beam constant, and it is possible to perform modeling with higher accuracy and excellent adhesive force between layers.

In the three-dimensional shape forming method according to the twelfth aspect, for example, the output of the light beam is measured at a predetermined timing, and the output of the light source is controlled based on the measurement result, so that the fluctuation of the output of the light source is suppressed. Therefore, it is possible to make the cured shape, the degree of curing, etc. of the resin during irradiation of the light beam constant, and thus it is possible to perform modeling with higher accuracy and excellent adhesive force between layers.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. Example 1 FIG. 1 shows a stereolithography apparatus used for carrying out Example 1. In FIG. 1, the stereolithography apparatus includes a light source 10 and a light source 1.
Optical scanning unit 1 for scanning the light emitted from 0 on the XY plane
1, a rectangular-frame-shaped resin liquid tank 12 that stores the photocurable resin liquid 15, a horizontal stand-shaped molding base 13 that is submerged in the resin liquid tank 12, and moves horizontally on the resin liquid tank 12. And a doctor blade (sweeping member) 14.

The light source 10 is, for example, a gas laser oscillation source that radiates ultraviolet laser light, and is mounted on the support stage 20. The optical scanning unit 11 is attached to the support stage 20 together with the light source 10. The optical scanning unit 11 includes three fixed mirrors 21, 22 and 23 that reflect the laser light from the light source 10, an X scanning mirror 24 that scans the light reflected by the fixed mirror 23 in the X direction, and an X scanning mirror 24. It has a Y scanning mirror 25 which scans the laser beam scanned in the X direction in the Y direction and irradiates the laser beam toward the resin liquid surface on the molding table 13. The X-scanning mirror 24 and the Y-scanning mirror 25 have respective drive units 26 and 27, and the laser beams are scanned in the respective directions by changing the inclination angle of the drive units 26 and 27. That is,
In the optical scanning unit 11, the laser light 1 projected from the light source 10
7 is deflected in two directions of X and Y by two scanning mirrors 24 and 25, and is irradiated onto the molding table 13.

A rectangular parallelepiped recess 12a is formed at one corner of the resin liquid tank 12, and a sensor 30 for detecting the irradiation position of the laser beam emitted from the light source 10 is provided in the recess 12a. ing. In addition, the sensor 30 is 1
A plurality of pieces may be provided instead of individual pieces. The sensor 30 includes, for example, a two-dimensional position detecting element (PSD),
It is possible to two-dimensionally detect the amount of deviation in the X and Y directions of the irradiation position of the laser light irradiated to the position from a predetermined position (usually the center of the light receiving surface). The sensor 30 is connected to the computer 31.

The computer 31 includes an X, Y drive unit 2
6, 27, the light source 10, the forming table elevating mechanism, and the doctor blade moving mechanism are also connected. The computer 31
The light source 10 and the X, Y drive units 26, 27 are controlled based on the scan data while controlling the movements of the forming table elevating mechanism and the doctor blade moving mechanism. Further, the computer 31 irradiates the sensor 30 with laser light at a predetermined timing, and when the sensor 30 detects the irradiation position, controls the drive units 26 and 27 based on the deviation amount from the predetermined position, and the scanning mirror 24. , 25 are tilted to correct variations in the irradiation position.

The molding table 13 can be moved up and down in the resin liquid 15 by an elevating mechanism (not shown) installed outside the resin liquid tank 12, and supports the formed photocurable layer 16. The doctor blade 14 can be horizontally moved by a horizontal moving mechanism (not shown) installed outside the resin liquid tank 12. The doctor blade 14 sweeps the resin liquid thin film formed on the molding table 13 or the photo-curing layer 16 previously formed by horizontal movement to sweep the resin liquid thin layer to a uniform thickness and smooth the surface. It is a member for.

Next, an example of the procedure for carrying out the first embodiment of the method of the present invention will be described with reference to the flow chart shown in FIG. When the computer 31 is powered on, in step S1 of FIG. 2, a predetermined command value is transmitted to the X, Y drive units 26, 27, the X, Y scanning mirrors 24, 25 are tilted, and the light receiving surface of the sensor 30 is detected. Laser light is radiated toward. In step S2, the laser beam irradiation position of the sensor 30 (X0, Y
0) is read. This irradiation position (X0, Y0) becomes the origin of the subsequent irradiation positions.

In step S3, the light source 10 and X, Y
Scan data is transmitted to the drive units 26 and 27. Step S
In 4, the laser light is scanned in the XY directions on the resin liquid surface. As a result, the exposed portion of the resin liquid 15 on the molding table 13 in the resin liquid tank 12 is cured by one layer into a predetermined shape, and the photo-cured layer 16 is formed. In step S5, the molding table 13 is lowered by a predetermined amount, and then the doctor blade 14 is operated.
As a result, a smooth resin liquid thin film having a constant thickness is formed on the formed photocurable layer 16. In step S6, it is determined whether or not the modeling of all the photo-cured layers 16 has been completed.
When the modeling of all the photo-curable layers 16 is completed, the process is terminated, and when the modeling is not completed, the process proceeds to step S7. In step S7, as in step S1, a predetermined command value is transmitted to the X, Y drive units 26, 27, the X, Y scanning mirrors 24, 25 are tilted and laser light is emitted toward the light receiving surface of the sensor 30. . In step S8, the sensor 30
The laser beam irradiation position (X1, Y1) is read. In step S9, the correction amount (ΔX, ΔY) is obtained from the difference between the irradiation position (X1, Y1) of this time and the origin (X0, Y0). In step S10, the scan data for shaping the next photo-curable layer 16 is corrected. Specifically, X (scan data after correction) = X (scan data before correction) −ΔX, Y
(Scan data after correction) = Y (scan data before correction) −
The data is corrected with ΔY. When the correction in step S10 is completed, the process returns to step S3, the scan data of the next photo-curable layer 16 is transmitted to the light source 10 and the X, Y drive units 26 and 27, and the subsequent operations are repeated until the modeling is completed.

In this embodiment, the sensor 30 corrects the irradiation position every time the layer is formed, and suppresses the fluctuation of the irradiation position. Therefore, the irradiation position is always constant, and the modeling accuracy is improved. Moreover, since the sensor 30 is fixed to one corner of the resin liquid tank 12, the measurement accuracy of the sensor 30 is improved. Embodiment 2 FIG. 3 shows a stereolithography apparatus used for carrying out Embodiment 2. In the following drawings, the same reference numerals are used for the same or corresponding members as in the first embodiment, and the description thereof will be omitted. Of the X, Y mirrors 24, 25 and their drive units 26, 27, the X mirror 24 and the X drive unit 26 are not shown, and the mirror 25 and the drive unit 27 are in the XY position.
The laser beam is scanned in the direction.

In FIG. 3, the sensor 30 is a resin liquid tank 1
It is provided on the support stage 20 to which the light source 10 is attached, instead of one corner. A beam splitter 28 that disperses the laser light from the fixed mirror 22 into two is disposed on the support stage 20. One of the laser beams split by the beam splitter 28 is fixed mirror 23.
The other laser beam is emitted to the center of the light receiving surface of the sensor 30. Since other configurations are similar to those of the first embodiment, description thereof will be omitted.

Next, the procedure for implementing the second embodiment will be described with reference to the flowchart of FIG. In the second embodiment, the processes of step S1 and step S7 are unnecessary. This is because the laser light is always applied to the sensor 30. Therefore, in the second embodiment, the operation starts from step S2. Then, step S3 to step S1
The operation up to 0 (excluding step S7) is repeated until the modeling is completed. The irradiation position may be measured not at each layer but at any timing (for example, every scanning in the X direction).

In the second embodiment, since the irradiation position can be constantly measured, the correction can be performed in real time at an arbitrary timing, and precise control such as feedback control can be performed. Third Embodiment FIG. 4 shows a stereolithography apparatus used for carrying out the third embodiment. Although the sensor is fixed in the first and second embodiments, the sensor is movably arranged in this embodiment.

In FIG. 3, on the doctor blade 14, three sensors 30a,
30b and 30c are arranged. The sensor 30a is arranged at the center of the doctor blade 14, the sensor 30b is arranged on the front side of the doctor blade 14 in FIG. 4, and the sensor 30c is arranged on the rear side of the doctor blade 14 in FIG. The other configurations are similar to those of the first embodiment (FIG. 1), and the description thereof will be omitted.

Next, an example of the procedure for carrying out the third embodiment is shown in FIG.
It will be described according to the flowchart shown in FIG. In step S11 of FIG. 5, the position of the doctor blade 14 is set to the position 1. This position 1 is the end of the resin liquid tank 12 as shown in FIG. In step S12, the command value (X'10, Y'10) to the drive unit 27 is set so that the irradiation position of the laser light coincides with the center position of the area A (light receiving surface of the sensor 30a) shown in FIG. To do. In step S13, the drive unit 27 receives the initial command value (X'10, Y '.
10) is transmitted, the scanning mirror 25 is tilted, and the sensor 30a
The laser light is emitted toward the light receiving surface of. Step S14
Then, it is determined whether or not the irradiation position (X1, Y1) coincides with the predetermined position (X10, Y10) in the area A. If the irradiation position does not match the predetermined position, the process proceeds to step S15. In step S15, the initial command value (X'1
0, Y'10) is corrected. Specifically, the deviation between the irradiation position and the predetermined position is subtracted from the initial command value (X'10 =
X'10- (X1-X10), Y'10 = Y'10-
(Y1-Y10)). When the correction is completed, the process returns to step S13, the corrected new initial command value is transmitted to the drive unit 27, and the step S1 is performed until the irradiation position and the predetermined position match.
The operations of 5 and S13 are repeated to correct the initial command value.

When the irradiation position matches the predetermined position,
The process moves from step S14 to step S16. In step S16, the position of the doctor blade 14 is set to the position 2. This position 2 is substantially the center of the resin liquid tank 12 as shown in FIG. 6, and is the center of the modeling area. In step S17, operations similar to those in steps S12 to S15 are performed in area B and area C, and the sensors 30a and 30b arranged in areas B and C are operated.
Initial command values (X'20, Y'20), (X'30,
Y'30) is calculated.

In step S18, the doctor blade 1
Return position 4 to position 1. In step S19,
Scan data is transmitted to the light source 10 and the drive unit 27, and the laser light is scanned in the XY directions of the resin liquid surface. As a result, the exposed portion of the resin liquid 15 on the molding table 13 in the resin liquid tank 12 is 1
The layer is cured into a predetermined shape, and the photo-cured layer 16 is formed.
In step S20, the molding table 13 is lowered by a predetermined amount, and then the doctor blade 14 is operated. As a result,
A smooth resin liquid thin film having a certain thickness is formed on the formed photocurable layer 16. In step S21, it is determined whether or not modeling of all layers has been completed. If the modeling of all layers is completed, the process is terminated, and if the modeling is not completed, the process proceeds to step S22.

At step S22, the initial command value (X'1
0, Y'10), (X'20, Y'20), (X'3
0, Y'30) is the command value (X'1, Y'1) of the next layer,
(X'2, Y'2), (X'3, Y'3). In step S23, the command values (X'1, Y '
1) is transmitted, the scanning mirror 25 is tilted, and laser light is emitted toward the light receiving surface of the sensor 30a. In step S24, it is determined whether the irradiation position (X1, Y1) coincides with the predetermined position (X10, Y10) in the area A. If the irradiation position does not match the predetermined position, the process proceeds to step S25. In step S25, command values (X'1, Y '
Correct 1). Specifically, the deviation between the irradiation position and the predetermined position is subtracted from the command value (X'1 = X'1- (X1-X
10), Y'1 = Y'1- (Y1-Y10)). When the correction is completed, the process returns to step S23, the corrected command value is transmitted to the drive unit 27, and the operations of steps S25 and S23 are repeated until the irradiation position and the predetermined position match, and the command value is corrected.

When the irradiation position coincides with the predetermined position,
The process moves from step S24 to step S26. In step S26, the position of the doctor blade 14 is set to the position 2. In step S27, operations similar to those in steps S22 to S25 are performed in area B and area C, and the sensors 30a arranged in areas B and C,
Command values (X'2, Y'2) to 30b, (X'3, Y '
Correct 3).

In step S28, each measurement area A,
In B and C, command values (X'1, Y'1), (X'2,
Y'2), (X'3, Y'3) and the initial command value (X'1
0, Y'10), (X'20, Y'20), (X'3
0, Y'30) deviation (ΔX1, ΔY1), (ΔX
2, ΔY2), (ΔX3, ΔY3), respectively.
Here, each deviation is ΔX1 = X'1-X'10, ΔY1 = Y'1-Y'10 ΔX2 = X'2-X'20, ΔY2 = X'2-X'20 ΔX3 = X'3-X. '30, ΔY3 = Y'3-Y'30
Is.

In step S29, the origin correction of the scanning data of the next layer is performed by the following equation. X (scan data after origin correction) = X (before correction) −ΔX2 Y (scan data after origin correction) = Y (before correction) −ΔY2 In step S30, the slope (α, β) of the command value difference is as follows. Calculate by formula. α = (ΔX1−ΔX2) / g β = (ΔY2−ΔY3) / h However, h = X20−X10 g = Y30−Y20 In step S31, the gradient (α,
According to β), the gain correction of the scanning data of the next layer is performed by the following formula.

X (scan data after gain correction) = X (after origin correction) + α (X (after origin correction) -X20) Y (scan data after gain correction) = Y (after origin correction) +
β (Y (after origin correction) -Y20) When the gain correction in step S31 is completed, step S
Returning to 18, the doctor blade 14 is set to the position 1, and the operations of steps S18 to S31 are repeated until the shaping is completed.

Here, the moving doctor blade 14
Since the sensors 30a and 30b are arranged in the above, it is possible to move the sensors 30a and 30b without using a special member. Further, by moving the plurality of sensors 30a and 30b to the end portion and the central portion of the resin liquid tank 12, not only the correction of the parallel movement on the resin liquid surface (origin correction) but also the reference point (end portion) It is also possible to perform correction (gain correction) in consideration of the increment of the shift amount due to the distance, and it is possible to correct fluctuations with higher accuracy and to perform modeling with even higher accuracy.

Fourth Embodiment In the third embodiment, two of the three sensors 30a, 30 are used.
Although the correction is performed in a fixed area by using b, in this embodiment, three sensors 30a to 30c are used and the doctor blade 14 is moved in synchronization with scanning to increase the number of correction points. . Since the structure is the same as that of the third embodiment, the description is omitted.

An example of the procedure for implementing the fourth embodiment will be described with reference to the flowchart shown in FIG. In step S41 of FIG. 7, the scanning mirror 25 of the optical scanning unit 11 and the doctor blade 14 are moved in synchronization with each other, and the sensor 30 is constantly operated.
The irradiation position is measured at a predetermined timing so that the laser light can be received by a, and the irradiation position data at a plurality of measurement points is obtained. The number of measurement points here is preferably as large as possible, but it is preferable to determine the number of measurement points in consideration of the measurement time and the arithmetic processing speed. In step S42, similarly, the sensor 30b is always allowed to receive the laser beam, and the irradiation position is measured at a predetermined timing. Similarly, in step S43, the sensor 30c is always used.
The laser beam can be received by and the irradiation position is measured at a predetermined timing. In this way, the initial values of the irradiation positions of the three sensors 30a to 30c are measured, and the initial position data of the irradiation positions are obtained.

In step S44, scan data is transmitted to the drive unit 27, and laser light is scanned in the XY directions of the resin liquid surface. As a result, the exposed portion of the resin liquid 15 on the molding table 13 in the resin liquid tank 12 is cured into a predetermined shape for one layer, and the photo-cured layer 16 having a predetermined thickness is formed. In step S45, the molding table 13 is lowered by a predetermined amount, and then the doctor blade 14 is operated. As a result, the formed photo-curable layer 16
On top of this, a smooth resin liquid thin film having a constant thickness is formed, which is a next photo-curing layer. In step S46, it is determined whether or not all the photo-cured layers have been formed. If the modeling of all the photo-curable layers is completed, the process is terminated, and if the modeling is not completed, the process proceeds to step S47.

In step S47, similarly to step S41, the scanning mirror 25 of the optical scanning unit 11 and the doctor blade 14 are moved in synchronization with each other so that the laser beam can always be received by the sensor 30a and the same timing as the initial position. Measure the irradiation position with. In step S48, similarly, the sensor 30b is always made to be able to receive the laser beam, and the irradiation position is measured at a predetermined timing. In step S49, similarly, the sensor 30c is always allowed to receive the laser beam, and the irradiation position is measured at the same measurement point at a predetermined timing. In this way three sensors 3
The irradiation position after the layer formation of 0a to 30c is measured.

In step S50, the deviation between the initial value and the irradiation position at each measurement point is obtained. In step S51, it is checked which measurement point the scan data of the next layer is closest to, and correction is performed by subtracting the correction amount (deviation between the initial value and the irradiation position) at that measurement point from the scan data. Then, the process returns to step S44, the scanning data of the next layer is transmitted, and the formation of the layer is repeated until the modeling is completed.

Here, using three sensors (a finite number of sensors), deviations (deviations) at an infinite number (a large number) of measurement points
Can be measured, and more accurate modeling is possible. Fifth Embodiment In the first to fourth embodiments, the correction is performed for each layer forming, but in this embodiment, the correction is performed for each constant layer forming or every constant time. Note that the configuration is similar to that of the above-described embodiment, so description will be omitted.

An example of the procedure for implementing the fifth embodiment will be described with reference to the flowchart shown in FIG. Here, the procedure will be described with the same configuration as that of the first embodiment, that is, the sensor 30 of FIG. 1 is fixed. However, the sensor may be movable. In step S61 of FIG. 7, a predetermined command value is transmitted to the X and Y drive units 26 and 27,
The X, Y scanning mirrors 24, 25 are tilted and laser light is emitted toward the light receiving surface of the sensor 30. In step S62,
The irradiation position (X0, Y0) of the laser light of the sensor 30 is read. This irradiation position (X0, Y0) becomes the origin of the subsequent irradiation positions.

In step S63, a variable i indicating the number of layers is
Is set to "0". In step S64, the scan data is transmitted to the light source 10 and the X, Y drive units 26, 27.
In step S65, the laser light is scanned in the XY directions of the resin surface. As a result, the exposed portion of the resin liquid 15 on the molding table 13 in the resin liquid tank 12 is cured into a predetermined shape for one layer.
In step S66, the variable i is incremented. In step S67, the molding table 13 is lowered by a predetermined amount, and then the doctor blade 14 is operated. Step S6
At 8, it is determined whether or not all layers have been formed.
If the modeling of all layers is completed, the process is terminated, and if the modeling is not completed, the process proceeds to step S69.
In step S69, in order to determine the correction timing, it is determined whether the variable i indicating the number of stacked layers is a number divisible by 10. That is, the correction timing is determined for each 10-layer stack.

When it is determined that the correction timing has been reached, step S6
The process proceeds from step 9 to step S70. In step S70, as in step S61, a predetermined command value is transmitted to the X, Y drive units 26, 27, and the X, Y scanning mirrors 24, 25 are tilted to irradiate the laser light toward the light receiving surface of the sensor 30. . In step S71, the irradiation position (X1, Y1) of the laser light of the sensor 30 is read. In step S72,
The correction amount (ΔX, ΔY) is obtained from the difference between the irradiation position (X1, Y1) at this time and the origin (X0, Y0). Step S
At 73, the scan data for forming the next photo-curing layer is corrected. Specifically, X (corrected scan data) = X
(Scan data before correction) −ΔX, Y (scan data after correction) = Y (scan data before correction) −ΔY to correct the data. When the correction in step S73 is completed, the process returns to step S64, the scan data of the next layer is transmitted to the light source 10 and the X, Y drive units 26, 27, and the subsequent operations are repeated until the modeling is completed. If it is determined in step S69 that it is not the correction timing, the process proceeds to step S73.

In this case, since the correction is performed for each constant layer (10 layers in the embodiment), the modeling can be performed at a higher speed than the correction for each layer. It should be noted that instead of performing correction for each constant layer, correction may be performed for each constant time. In this case, the determination in step S69 may be determined not by the number of layers but by time, and for example, the correction may be performed every 10 minutes from the start of modeling.

Example 6 In Examples 1 to 5, only the irradiation position was corrected, but Example 6
Then, the fluctuation of the focal length is further corrected. FIG. 9 shows a stereolithography apparatus used for carrying out the sixth embodiment. In the figure, in addition to the configuration shown in FIG. 1, the optical modeling apparatus is a concave portion in which a focal length adjuster 29 arranged between the fixed mirror 23 and the scanning mirror 25 and a sensor 30 of the resin liquid tank 12 are arranged. A beam diameter measuring sensor 32 is provided in a concave portion 12b that is symmetrical to 12a, with the light receiving portion facing upward. As shown in FIG. 10, the focal length adjuster 29 has a convex lens 35 and a concave lens 36 whose intervals can be adjusted. The distance L between the lenses 35 and 39 is controlled by a command value from the computer 31. Here, when the distance L is increased, the focal length becomes longer, and when the distance L is decreased, the focal length becomes shorter. The sensor 32 is of a slit type having, for example, a light receiving portion and a slit that moves in front of the light receiving portion, and is connected to the computer 31. The sensor 32 moves the slit at the time of measurement, and the computer 3
1 calculates the beam diameter by measuring the time during which the light receiving portion of the sensor 32 detects light.

Next, an example of the procedure for carrying out the sixth embodiment is shown in FIG.
A description will be given according to the flowchart shown in FIG. Figure 11
In step S81, a predetermined command value is transmitted to the drive unit 27, the scanning mirror 25 is tilted, and laser light is emitted toward the light receiving surface of the sensor 30. In step S82, the irradiation position (X0, Y0) of the laser light of the sensor 30 is read.
This irradiation position (X0, Y0) becomes the origin of the subsequent irradiation positions.

In step S83, the scanning data is transmitted to the light source 10 and the drive unit 27, and the laser light is applied to the XY of the resin liquid surface.
Scan in the direction. As a result, the molding table 1 in the resin liquid tank 12
The exposed portion of the resin liquid 15 on 3 is cured into a predetermined shape for one layer, and a photo-cured layer 16 having a predetermined thickness is formed. In step S84, the molding table 13 is lowered by a predetermined amount, and then the doctor blade 14 is operated. As a result, a resin liquid thin film as a next layer is formed on the photo-curable layer 16. In step S85, it is determined whether or not all the photo-cured layers 16 have been formed. If the modeling of all layers is completed, the process is terminated, and if the modeling is not completed, step S
Move to 86. In step S86, a predetermined command value is transmitted to the drive unit 27, the scanning mirror 25 is tilted, and the sensor 3
The laser light is emitted toward the second light receiving portion. Step S8
In 7, the beam diameter is measured by the output of the sensor 32.
In step S88, it is determined whether or not the measured beam diameter is within a predetermined range. When the beam diameter is smaller than the predetermined range, the process proceeds from step S88 to step S89, the lens distance L of the focal length adjuster 29 is increased by a predetermined length to increase the focal length, the beam diameter is increased, and the process proceeds to step S87. Return and measure the beam diameter again. When the beam diameter is larger than the predetermined range, the process proceeds from step S88 to step S90, the lens distance L of the focal length adjuster 29 is shortened by a predetermined length to shorten the focal length, the beam diameter is reduced, and the process proceeds to step S87. Return and measure the beam diameter again. As a result, the resin liquid 15 is always irradiated with laser light having a beam diameter within a predetermined range.

If the beam diameter is within the predetermined range, step S
The routine proceeds from step 87 to step S91, where a predetermined command value is transmitted to the drive unit 27 as in step S81, and the scanning mirror 2
The laser light is emitted toward the light receiving surface of the sensor 30 by inclining the lens 5. In step S92, the irradiation position (X1, Y1) of the laser light of the sensor 30 is read. In step S93, the irradiation position (X1, Y1) of this time and the origin (X0, Y)
The correction amount (ΔX, ΔY) is calculated from the difference from 0). In step S94, the scan data for forming the next photo-cured layer is corrected. Specifically, X (scan data after correction)
= X (scan data before correction) −ΔX, Y (scan data after correction) = Y (scan data before correction) −ΔY to correct the data. When the correction in step S94 is completed, the process returns to step S83, the scan data of the next layer is transmitted to the light source 10 and the drive unit 27, and the subsequent operations are repeated until the modeling is completed.

Here, not only the deviation of the irradiation position is corrected but also the focal length (beam diameter) is corrected, so that the cured shape, the degree of curing, etc. of the resin at the time of laser light irradiation can be kept constant and higher accuracy can be obtained. With this, it becomes possible to perform modeling with good adhesion between layers. Example 7 In Examples 1 to 5, only the irradiation position was corrected, but Example 7
Then, the output fluctuation of the light source 10 is further corrected.

FIG. 12 shows a stereolithography apparatus used for carrying out the seventh embodiment. In the figure, in addition to the configuration shown in FIG. 1, the stereolithography apparatus is symmetrical to the light source control unit 33 connected between the light source 10 and the computer 31 and the recess 12a in which the sensor 30 of the resin liquid tank 12 is arranged. And a sensor 34 for measuring the beam power, which is arranged in the concave portion 12b with the light receiving portion facing upward. The light source control unit 33 controls the output of the light source 10 according to a command value from the computer 31.
The sensor 34 is, for example, an ordinary optical sensor including a light receiving unit, and outputs a signal according to the amount of received light (beam power) to the computer 31.

Next, an example of the procedure for implementing the seventh embodiment is shown in FIG.
A description will be given according to the flowchart shown in FIG. FIG.
In step S101, a predetermined command value is transmitted to the drive unit 27, the scanning mirror 25 is tilted, and laser light is emitted toward the light receiving surface of the sensor 30. In step S102, the irradiation position (X0, Y0) of the laser light of the sensor 30 is read. This irradiation position (X0, Y0) becomes the origin of the subsequent irradiation positions.

In step S103, the scanning data is transmitted to the light source 10 and the driving unit 27, and the laser light is applied to the X level of the resin surface.
Scan in the Y direction. As a result, the exposed portion of the resin liquid 15 on the molding table 13 in the resin liquid tank 12 is cured into a predetermined shape for one layer, and the photo-cured layer 16 having a predetermined thickness is formed. In step S104, the molding table 13 is lowered by a predetermined amount, and then,
The doctor blade 14 is operated. As a result, a smooth resin liquid thin film having a predetermined thickness is formed on the photocurable layer 16 as the next photocurable layer. In step S105, it is determined whether or not modeling of all layers has been completed. If the modeling of all layers is completed, the process is terminated, and if the modeling is not completed, the process proceeds to step S106. Step S1
In 06, a predetermined command value is transmitted to the drive unit 27, the scanning mirror 25 is tilted, and the laser light is emitted toward the sensor 34. In step S107, the beam power is measured by the output of the sensor 34. In step S108, it is determined whether the measured beam power is within a predetermined range. If the beam power is smaller than the predetermined range, step S108.
Then, the process proceeds to step S109, and a command value for increasing the power of the light source 10 by a predetermined power is output to the light source control unit 33. As a result, the output of the light source 10 is increased by a predetermined power. Then, returning to step S107, the beam power is measured again. If the beam diameter power is larger than the predetermined range, the process proceeds from step S108 to step S11, and a command value for reducing the power of the light source 10 by the predetermined power is output to the light source control unit 33. As a result, the output of the light source 10 is reduced by a predetermined power. Then, returning to step S107, the beam power is measured again. As a result, the resin liquid 15 is always irradiated with laser light having a power within a predetermined range.

If the beam power is within the predetermined range, the process proceeds from step S107 to step S111, and then step S111.
Similar to 101, a predetermined command value is transmitted to the driving unit 27, the scanning mirror 25 is tilted, and laser light is emitted toward the light receiving surface of the sensor 30. In step S112, the irradiation position (X1, Y1) of the laser light of the sensor 30 is read. In step S113, the correction amount (ΔX, ΔY) is obtained from the difference between the irradiation position (X1, Y1) of this time and the origin (X0, Y0). In step S114, the scan data for forming the next photo-cured layer is corrected. Specifically, X (scan data after correction) = X (scan data before correction) −ΔX, Y
(Scan data after correction) = Y (scan data before correction) −
The data is corrected with ΔY. When the correction in step S114 is completed, the process returns to step S103, the scan data of the next layer is transmitted to the light source 10 and the drive unit 27, and the subsequent operations are repeated until the modeling is completed.

In this case, not only the deviation of the irradiation position is corrected but also the beam power is controlled within a predetermined range.
By keeping the cured shape, the degree of curing, etc. of the resin at the time of laser light irradiation constant, it becomes possible to perform modeling with higher accuracy and good adhesive force between layers. Other Examples (a) In the above examples, an ultraviolet beam or another beam may be used instead of the laser beam.

(B) The installation positions of the sensors 30, 32, 34 are merely examples, and may be any positions as long as they can receive laser light.

[0065]

As described above, according to the method for forming a three-dimensional shape according to the first aspect of the present invention, the irradiation position of the light beam is measured, and the irradiation position changes based on the measured position. Since the correction is performed, the irradiation position is less likely to change, and modeling can be performed with high accuracy.

In the three-dimensional shape forming method according to the second aspect, since the irradiation position is measured by one or a plurality of fixed sensors, the position of the sensor is surely fixed and the measurement accuracy is improved. Highly accurate modeling is possible. In the method for forming a three-dimensional shape according to claim 3, since the irradiation position is measured by the sensor arranged at substantially the same height as the light source of the light beam, it is affected by the deflection of the supporting member of the optical system. In addition, the problem of adhesion of resin liquid does not occur, the measurement accuracy is further improved, and the deterioration of the sensor performance can be prevented.

In the method for forming a three-dimensional shape according to the fourth aspect, since the light beam is dispersed and the irradiation position of one spectral beam is measured by the sensor, the irradiation position of the light beam being irradiated on the resin liquid layer is determined. You can accurately correct fluctuations in real time,
It is possible to perform modeling with higher accuracy. In the method for forming a three-dimensional shape according to claim 5, since the irradiation position of the light beam at a predetermined position is recognized using one or a plurality of moving sensors, the irradiation position of the moving light beam can be accurately measured in a wide range. Can be measured.

In the method for forming a three-dimensional shape according to the sixth aspect, since the irradiation position is measured by the sensor attached to the sweeping member, the sensor can be moved without using another moving member. In the method for forming a three-dimensional shape according to claim 7, since the sweeping member is stationary at the center and the end of the modeling area of the modeled object, not only the correction of the parallel movement on the resin liquid surface (origin correction), but also the The correction (gain correction) can be performed in consideration of the increment of the shift amount due to the distance from the reference point (end portion), and the variation can be corrected with higher accuracy.

In the method for forming a three-dimensional shape according to the eighth aspect, since the light beam moves in synchronization with the horizontal movement operation of the sweeping member, fluctuations in arbitrary irradiation position during irradiation by a plurality of finite sensors. Can be corrected, and modeling can be performed with higher accuracy. In the method for forming a three-dimensional shape according to the ninth aspect, the variation correction is performed each time each photo-cured layer is obtained, so that the modeling accuracy of each photo-cured layer is further improved.

In the three-dimensional shape forming method according to the tenth aspect, since the variation correction is performed every fixed time and / or each time a fixed layer is obtained, the modeling accuracy is further improved. Claim 1
In the method for forming a three-dimensional shape according to the first aspect, for example, the focal length and / or the beam diameter of the light beam are measured at a predetermined timing, and in addition to the correction of the variation of the irradiation position, the variation of the focal length of the light beam is further corrected. Therefore, it is possible to make the cured shape, the degree of curing, etc. of the resin at the time of irradiation of the light beam constant, and it is possible to perform modeling with higher accuracy and excellent adhesive force between layers.

In the three-dimensional shape forming method according to the twelfth aspect, for example, the output of the light beam is measured at a predetermined timing, and the output of the light source is controlled based on the measurement result, so that the fluctuation of the output of the light source is suppressed. Therefore, it is possible to make the cured shape, the degree of curing, etc. of the resin during irradiation of the light beam constant, and thus it is possible to perform modeling with higher accuracy and excellent adhesive force between layers.

[Brief description of drawings]

FIG. 1 is a perspective view of a stereolithography apparatus used for carrying out a first embodiment of the present invention.

FIG. 2 is a flowchart showing the implementation procedure.

FIG. 3 is a perspective view of an optical modeling apparatus used for carrying out Example 2.

FIG. 4 is a perspective view of an optical modeling apparatus used for carrying out Example 3.

FIG. 5 is a flowchart showing an implementation procedure thereof.

FIG. 6 is a plan view illustrating a measurement area.

FIG. 7 is a flowchart showing an implementation procedure of the fourth embodiment.

FIG. 8 is a flowchart showing an implementation procedure of the fifth embodiment.

FIG. 9 is a perspective view of an optical modeling apparatus used for carrying out Example 6.

FIG. 10 is a schematic diagram showing a configuration of a focal length adjuster.

FIG. 11 is a flowchart showing an implementation procedure of the sixth embodiment.

FIG. 12 is a perspective view of an optical modeling apparatus used for carrying out Example 7.

FIG. 13 is a flowchart showing an implementation procedure thereof.

FIG. 14 is a graph showing changes over time in irradiation position.

[Explanation of symbols]

 10 Light Source 11 Optical Scanning Section 12 Resin Liquid Tank 13 Molding Table 14 Doctor Blade 15 Photosetting Resin 16 Photocuring Layer 17 Laser Light 24, 25 X, Y Scanning Mirrors 26, 27 X, Y Drive 28 Beam Splitter 29 Focal Length Adjuster 30, 30a to 30c Sensor 31 Computer 32, 34 Sensor 33 Light source controller

Front Page Continuation (72) Inventor Kima Higashi 1048, Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works Co., Ltd.

Claims (12)

[Claims] 1. A molded article having a desired three-dimensional shape by irradiating a light beam on a photocurable resin liquid stored in a resin liquid tank to form a photocurable layer, and stacking a plurality of the photocurable layers. In the method for obtaining a three-dimensional shape, the irradiation position of the light beam is measured, and the variation of the irradiation position of the light beam is corrected based on the measurement result. 2. The method for forming a three-dimensional shape according to claim 1, wherein the irradiation position is measured by one or a plurality of fixed sensors. 3. The irradiation position is measured by a sensor arranged at substantially the same height as the light source of the light beam.
A method for forming a three-dimensional shape as described. 4. The method for forming a three-dimensional shape according to claim 3, wherein the light beam is dispersed, and the irradiation position of one spectral beam is measured by the sensor. 5. The method for forming a three-dimensional shape according to claim 1, wherein the irradiation position of the light beam at a predetermined position is recognized by using one or a plurality of moving sensors. 6. The sensor is attached to a molding table or a sweeping member that sweeps at least a part of the resin liquid layer formed on the photo-cured layer formed previously by horizontal movement. A method for forming a three-dimensional shape as described. 7. The method for forming a three-dimensional shape according to claim 6, wherein the sweeping member is stopped at a central portion and an end portion of a shaping area of the shaping object. 8. The method for forming a three-dimensional shape according to claim 6, wherein the light beam is synchronized with a horizontal movement operation of the sweeping member. 9. The method for forming a three-dimensional shape according to claim 1, wherein the variation correction is performed every time each photocured layer is obtained. 10. The method for forming a three-dimensional shape according to claim 1, wherein the variation correction is performed every constant time and / or every time a constant layer is obtained. 11. The method for forming a three-dimensional shape according to claim 1, wherein the focal length and / or the beam diameter of the light beam is measured to further correct the variation in the focal length of the light beam. 12. The method for forming a three-dimensional shape according to claim 1, wherein the output of the light beam is measured and the output of the light source is controlled.