JP2004223774A - Thin film curing type optical shaping method and apparatus thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical shaping method capable of extremely reducing the thickness of each of the cured material layers formed on the surface of a shaping base plate to form an extremely thin layer with a thickness of 20 μm or below and capable of easily shaping an optically shaped article of high precision for a relatively short time, and an apparatus for the method. <P>SOLUTION: A lens group wherein a large number of fine lenses each of which has a focus at a position extremely near to the surface of the lens is used and the light from a light source is condensed and applied to the lens group corresponding to a desired shape desired to be cured to cure a photo-setting resin in a spotted state. The spot of the light is successively moved in an X- or Y-direction to connect spot-like cured parts in a planar state to form a thin film corresponding to one layer. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical molding method and apparatus of a regulated liquid level method for thinly curing a photocurable resin and laminating molding.
[0002]
[Prior art]
An optical molding method and device using a regulated liquid surface method that irradiates light energy to the photocurable resin in the resin tank from below the resin tank and forms a resin cured layer on the lower surface of the molding base plate placed in the resin liquid is proposed. Have been.
This stereolithography device uses a liquid crystal panel driven based on shape data according to a target shape as an optical shutter, and passes light from a surface light source into a parallel light through a light transmitting portion of the liquid crystal panel to a photocurable resin. Irradiation, curing the divided pattern portion of the irradiated surface shape to form a first-layer molded object having a desired shape, and then moving the liquid crystal panel to the next predetermined position by a moving means, and performing a similar process. It is trying to obtain a multilayered object repeatedly.
[0003]
However, in this prior art, since the entire liquid crystal panel is irradiated with the light of the surface light source at one time, the entire liquid crystal panel is constantly exposed to heat rays and overheated, and the molding accuracy is reduced due to deformation or malfunction of the liquid crystal mask. Since the light from the surface light source passes through the light-transmitting part of the liquid crystal panel from all directions, the light transmitted obliquely through the light-transmitting part illuminates parts that should not be illuminated. There was a problem that it could not be obtained.
Further, since the surface light source also irradiates the periphery of the liquid crystal mask, the light utilization efficiency of the light source is extremely low. Therefore, a large amount of power is required to maintain a predetermined illuminance on the irradiation surface of the photocurable resin. There was a problem.
[0004]
Further, the prior art irradiates the photocurable resin with light that is close to a parallel light beam. Therefore, the control of the thickness of the cured layer mainly depends on the sensitivity of the photocurable resin. Since the sensitivity of the photocurable resin is adjusted so that it does not cure even if some light hits the resin, in the prior art, the thickness of the cured layer of each layer is about 1000 microns, and at least about 100 microns even if it is thin. However, since a thin cured layer having a thickness less than this could not be obtained, a step was generated in the optically molded article, and the precision was deteriorated.
[0005]
In addition, the thickness of the cured layer is easily determined to be controllable by the amount of movement of the modeling base plate. However, since the light used is close to a parallel ray, the size of the modeling object for an effective depth of one layer is hardened. When the thickness was larger than the layer, the thickness of the cured layer was as large as about 100 μm due to the characteristics of the resin, and it was not possible to perform the additive manufacturing.
[0006]
It is also known to irradiate a photocurable resin with a laser beam based on shape data as another optical molding method or apparatus, but there is a disadvantage that it takes a long time to form one molded object. Was. Further, the lamination pitch is usually 100 microns, and it has been difficult to make it thinner.
[0007]
[Problems to be solved by the invention]
The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to reduce the thickness of a cured product layer of each layer formed on the surface of a modeling base plate to, for example, 20 μm or less. It is an object of the present invention to provide a stereolithography method and apparatus capable of easily modeling a stereolithographic object with high accuracy in a relatively short time.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the thin-film curing type optical shaping method of the present invention irradiates light energy to a photocurable resin in a resin tank from below the resin tank, and cures the resin on a lower surface of a molding base plate arranged in a resin liquid. An optical shaping method based on a regulated liquid surface method for forming an object layer, using a lens group in which a large number of fine lenses having a focal point very close to the lens surface are arranged, and a shape from which light from a light source is desired to be cured. The light-curable resin is cured in the form of a spot by condensing and irradiating the lens group corresponding to, and the spot-shaped cured portion is connected in a plane by sequentially moving the light spot in the X direction or the Y direction, thereby forming one layer. It is characterized by forming a thin film.
[0009]
Further, in the thin film curing type stereolithography method of the present invention, the thin film is formed by connecting the spot-shaped cured portions in a plane, and then the thin film is moved upward, and the photocurable resin under the thin film is gathered into a lens group. Irradiate light to cure the photo-curable resin into spots, and move the light spots sequentially in the X or Y direction to connect the spot-shaped cured portions in a plane to create the next layer of film. Is repeated one or more times.
Preferably, a fine lens having a focal point very close to the lens surface having a diameter of 300 microns or less and a light focal length of 20 microns or less from the surface of the transparent plate in contact with the photocurable resin is used. .
[0010]
Also, preferably, a digital micromirror device is used as a means for irradiating light to a lens group in which a large number of fine lenses having a focal point very close to the lens surface are arranged, and ON / OFF of the micromirror group is selected. Then, a plurality of photocurable resins are cured in a spot with a focal point corresponding to the number of lenses, and then the focal point is moved in parallel by the lens pitch to form a thin film.
[0011]
In order to achieve the above object, the thin-film curing type optical shaping apparatus of the present invention stores a photocurable resin in a resin tank having a transparent plate on the bottom surface, and moves a modeling base plate arranged in the resin tank close to the transparent plate. An optical shaping apparatus using a regulated liquid level method, wherein a resin in the resin tank is irradiated with light from below the resin tank to form a hardened material layer having a predetermined thickness on a lower surface of the modeling base plate. A main optical system composed of a multi-point condensing spot lens using a fine lens having a focal point in the vicinity, and a digital optical system that irradiates light from a light source as parallel light corresponding to the fine lens constituting the main optical system. A micromirror device, means for sequentially moving the optical system in the X or Y direction, and means for moving the modeling base plate in the vertical direction.
[0012]
Preferably, the thin-film curing type optical shaping apparatus according to the present invention, wherein the lens of the main optical system has a diameter of 300 μm or less and a focal length of light of 20 μm or less from the surface of the transparent plate in contact with the photocurable resin. It is.
[0013]
[Action]
The present invention irradiates the photocurable resin in the tank in a spot-like manner with light through a group of finer lenses below the resin tank to form a spot-like cured layer on the lower surface of the modeling base plate. Since a lens group in which a number of fine lenses having a focal point are arranged very close to the lens surface is used, the thickness of the hardened layer can be 20 μm or less. However, the hardened layer is scattered in an island shape and does not become a plane as it is. Therefore, the lens group and the cured layer are relatively moved in the horizontal direction, whereby the uncured photo-curable resin is sequentially cured, connected to a planar shape, and an extremely thin film is formed.
[0014]
In order to obtain a three-dimensional molded product, when the first layer is cured, the base plate is moved in the Z-axis direction by a predetermined amount by the Z-axis direction elevating device. Since the uncured photocurable resin is under the first layer, the above process forms a second layer integrated therewith under the first layer. By repeating the required number of times, a three-dimensional stereolithographic object is created with high accuracy.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
1 to 9 show an example of a thin-film curing type optical shaping apparatus according to the present invention.
In FIG. 1, reference numeral 1 denotes a resin molding tank, which is composed of a side wall plate 1a having no light transmittance and a transparent bottom plate 1b made of quartz glass or the like, and is entirely supported by a support (not shown). The photocurable resin 2 is stored with the bottom plate 1b as the bottom. The inner surface of the bottom plate 1b, that is, the surface in contact with the photocurable resin 2, is coated with a transparent release thin film 10, such as Teflon or diamond-like carbon, so that the cured layer and the final molded product can be easily removed. ing.
[0016]
Reference numeral 3 denotes a modeling base plate which is immersed in the photocurable resin 2 in the resin modeling tank 1, which is a light-shielding face plate larger than the maximum dimension of the modeled object to be modeled. The modeling base plate 3 is provided integrally and moves up and down at an arbitrary pitch by moving the Z-axis stage 4.
[0017]
Reference numeral 5 denotes an airframe located below the resin molding tank 1, which has an XY-axis stage 6 movable in two horizontal directions and a mount 7 fixed to the stage, and the mount 7 is a bottom plate of the resin molding tank 1. 1b is provided with a rigid base 7a opposed to 1b.
The drive controllers 4c and 6c of the Z-axis stage 4 and the XY-axis stage 6 are connected to a controller 8 including an external CPU. CAD data is input to the controller 8, and signals are sent to the drive control units 4c and 6c of the Z-axis stage 4 and the XY-axis stage 6 according to the information, so that the moving direction and the moving amount are automatically controlled. Has become.
[0018]
Reference numeral 9 denotes a main optical system mounted on a hard and transparent base 7a such as quartz glass of the gantry 7. The main optical system 9 includes a lens group that can form a multifocal light spot SP from parallel light.
Specifically, as shown in FIG. 3, an array of many fine lenses 90 having a focal point near the lens surface, such as a hemispherical lens or a ball lens, or a microlens array is used.
[0019]
The reason why the fine lens 90 is used in the present invention is to control the thickness of one hardened layer to 20 microns or less, and it is preferable that the unit lens has a diameter of about 300 microns or less. This makes it possible to control the focal length from the lens surface to 20 microns or less from the surface of the bottom plate 1b when a parallel light beam is irradiated. The focal length can be finely adjusted by changing the lens material, that is, the refractive index. It is also possible to similarly decrease the focal length by reducing the diameter of the lens.
[0020]
The fine lenses 90 are arranged directly on the base 7a or on another transparent plate in a zigzag pattern as shown in FIG. 3 (a) or in a parallel pattern as shown in FIG. 3 (b). Are fixed by a fixing medium. The lens group is arranged such that the surface is close to or in contact with the lower surface of the bottom plate 1b.
[0021]
Reference numeral 11 denotes an intermediate optical system disposed behind the third optical system 9, and reference numeral 12 denotes a source optical system including a mirror device 14 disposed on the optical axis of the intermediate optical system 11 behind. Each optical system is mounted on the gantry 7 and is moved together with the gantry 7.
The source optical system 12 includes an arbitrary light source 12a having a wavelength of, for example, 350 to 450 mm, such as a metal halide lamp, and a lens 12b for irradiating the mirror device 14 with light from the light source. As the lens 12b, a collimating lens or the like can be used.
The intermediate optical system 11 includes lenses 11a and 11b that expand the parallel light from the mirror device 14 in accordance with the pitch of the fine lens 90 in the main optical system 9 and output the parallel light. The lenses 11a and 11b are optional such as a Kepler beam expander as shown in FIGS. 4 and 5, a Galileo beam expander as shown in FIGS.
[0022]
As the mirror device 14, a normal mirror can be used, but a digital micromirror device is preferably used. The digital micromirror device is a light-modulating semiconductor chip composed of a very small mirror (micromirror) 14a of, for example, 16 × 16 μm. That is, the micromirror 14a is a MEMS element (general term for a microsystem in which micro-sized sensors, actuators, and control circuits are integrated) laid on the base 14b at fine intervals as schematically shown in FIG. The micromirrors 14a are electromechanically controlled by a digital signal from now on, and can be tilted so that they do not hit each other at angles of +10 degrees (on) and -10 degrees (off). Has become. Each of the micromirrors 14a can be switched on / off at an extremely high speed of several thousand times or more per second.
Although FIG. 2 shows only 3 × 3 mirrors, actually the same number of fine lenses 90 as, for example, 1280 × 1024 are used.
[0023]
When light is applied, the light hitting the micromirror 14a 'in the off state goes outward, is absorbed by a light absorbing plate (not shown), and only the light hitting the micromirror 14a in the on state passes through the intermediate optical system 11. The light is sent to the fine lens 90 in the main optical system 9. Accordingly, even when the planar shape of the modeled object A is a ring shape having a space a in an appropriate place or a shape with irregularities in the periphery as shown in FIG. By doing so, it is possible to respond freely.
[0024]
Note that the intermediate optical system 11 may be omitted and the main optical system 9 may be directly irradiated with parallel light from the mirror device 14 depending on the type of the fine lens 90 used.
FIGS. 9 and 10 show examples of such a case. FIG. 9 shows a case where the reflected light is sent to each one micro lens 90 for each mirror of the mirror device 14 as parallel light without being enlarged. Is shown. In FIG. 10, reflected light from a plurality of micromirrors is transmitted to each microlens 90.
[0025]
However, when the fine lens 90 of the main optical system 9 is almost the same as the size of the micromirror, the focal length is too short. Therefore, the fine lens 90 having a size larger than the micromirror is used, and one micromirror is used. In order to adjust the reflected light to the size of one lens, it is preferable to use the intermediate optical system 11.
FIG. 11 and FIG. 12 show an example thereof. FIG. 11 enlarges the reflected light by the intermediate optical system 11 in accordance with the size of each micro lens 90 for one micro mirror. FIG. 12 enlarges the reflected light of a plurality of micromirrors in the intermediate optical system 11 according to the size of one microlens 90.
In FIGS. 9, 10 and 11, one micromirror is turned off and the light is not incident on the microlens 90. This is because it is possible to cope with the above-described molded shape.
[0026]
In another embodiment of the present invention, instead of moving the optical system, the film side, that is, the resin molding tank 1 may be moved in the XY axes. In this case, the gantry 7 is fixed in position, the resin molding tank 1 is mounted on the outer frame-shaped XY-axis stage, and driven by the controller 8.
[0027]
The thin-film curing type optical shaping method of the present invention will be described. First, the shape and dimensions to be formed are converted into data by CAD, and the data is input to the controller 8. The controller 8 determines the number and position of the micromirrors of the mirror device 14 to be turned off according to the shape and dimensions to be formed, and determines the amount of movement in the XY axis direction, the amount of movement in the Z axis direction, and the light amount of the light source. I do. .
Photocurable resin 2 is arbitrary, for example, as the epoxy, the critical exposure Ec is SCR9120 of SCR710,10.9J / cm ² of SCR7001,13mJ / cm ² of 33 mJ / cm ² is used, a resin molded tank Stored in 1.
[0028]
When a signal from the controller 8 is sent to the mirror device 14, the micro mirror 14a at a position corresponding to the shape and size to be formed is turned on / off. The micromirror in the molding contour is turned on when the shaping shape has no unevenness in the plane or when there is no void, but when the shaping shape has no unevenness in the plane or as illustrated in FIG. If there is a space a, the micro mirror at the position corresponding to the space a is turned off. Of course, the micromirrors outside the contour are also turned off.
The signal from the controller 8 is also sent to the drive control section 4c of the Z-axis stage 4, whereby the Z-axis stage 4 is lowered and the modeling base plate 3 is held at a position close to the bottom plate 1b of the resin modeling tank 1. Further, a signal from the controller 8 is sent to the light source 12a, and light is irradiated with an appropriate amount of light.
[0029]
The light from the light source 12a is applied to the mirror device 14, and the parallel light is reflected by each micro mirror. The parallel light from the on-state micromirror 14a is enlarged by the intermediate optical system 11 in accordance with the size and pitch of the fine lens 90 of the main optical system 9, and is incident on the main optical system 9 as parallel light. Since the main optical system 9 is composed of a lens group in which a number of fine lenses 90 having a focal point near the lens surface are arranged, at the moment when the light is irradiated, light is applied as shown in FIGS. 13 (a) and 14 (a). The curable resin 2 is cured at a time with multiple spots condensed so as to have a critical exposure amount or more. SP is a condensing spot, and 20 is a spot-shaped (island-shaped) hardened portion.
[0030]
In surface exposure, it is necessary to irradiate the resin with light larger than the critical exposure amount of the photocurable resin, so a strong light source is required, but this light must be sharply condensed by a multi-point lens. Thereby, it becomes possible to cure only the resin in the portion where the energy density of light is increased. By making the angle acute, the curing depth is shallow, and it is possible to cure as thin as 20 microns or less. That is, the curing depth can be reliably controlled. Since the light that is more than the critical exposure amount is produced by condensing with a lens and the resin is cured, even if the resin is irradiated with the light that has passed through the gaps between the fine lenses, that portion is not cured.
[0031]
Next, the signal from the controller 8 is sent to the drive unit 6c of the XY-axis stage 6, whereby the XY-axis stage 6 and the optical system mounted thereon move horizontally. As a result, the condensed spot SP from the lens group in which a large number of fine lenses 90 having a focal point near the lens surface are arranged continuously translates in the X direction or the Y direction by one lens group pitch.
FIG. 13B shows a state during the movement, and FIGS. 13C and 14B show a state in which the lens has moved by the distance between the lenses. In this example, the condensed spot SP moves rightward to connect the spot-shaped cured portions 20 and 20 ′ to form a surface 200 having a predetermined width of 20 μm or less.
[0032]
FIGS. 15A to 15D show a state in which one layer is formed. As shown in FIG. 15A, the light spot is moved in the X direction to form a predetermined surface 200, and then the Y direction is formed. After moving to the spot diameter or appropriately less than the spot diameter, move to the left and connect to the surface 200 'in the second row as shown in (b). Then, after moving in the Y direction by an amount equal to or smaller than the spot diameter and moving to the right, the surface is moved to the right and connected as the surface 200 "in the third row, as shown in (d). The necessary surface is formed, and the first cured layer A is completed.
In order to obtain the center space a in FIG. 15, the micromirror 14a paired with the fine lens 90 corresponding to the space a may be turned off, so that it is easy to cope with it.
[0033]
FIG. 16A schematically shows a state in which the first hardened layer A is formed. The first hardened layer A having a thickness t of 20 μm or less is adhered to the lower surface of the formed base plate 3. ing.
Next, the irradiation of the light from the light source 12a is temporarily stopped, and the Z-axis stage 4 is raised by a predetermined amount according to a signal from the controller 8. Since the lower surface of the first hardened layer A is in contact with the transparent peeling thin film 10, it is easily peeled off and rises together with the modeling base plate 3 as shown in FIG.
[0034]
After confirming this state, light is again emitted from the light source 12a. Thus, the lower surface of the first cured layer A is used as a modeling base plate to form a spot-shaped cured portion with the condensed spot SP in the same manner as in the case of the first layer, and the condensed spot SP is formed in the XY axis directions. By moving and connecting the spot-shaped cured portions, a second cured layer is formed. The second cured layer is adhered and laminated to the first cured layer A. By repeating the above steps the required number of times, a high-precision stereolithographic object having a desired shape can be obtained.
[0035]
In the present invention, the plurality of cured layers are not limited to an embodiment in which all of the cured layers are formed to have the same thickness and laminated. Films having different thicknesses may be formed and laminated. This includes, for example, a part that requires precision of the optically formed object and a part that does not.
This is because, under the condition that the focal point of the lens is fixed, the moving distance of the modeling base plate 3 in the Z-axis direction, that is, the pitch of the stacking interval may be changed, and a signal may be sent from the controller 8 to the light source 12a to control the light amount. What is necessary is just to change the critical exposure amount to resin.
FIG. 17 schematically shows this. When a layer corresponding to a portion requiring accuracy is formed, the moving distance of the forming base plate 3 in the Z-axis direction is reduced, and light energy is irradiated at an appropriate critical exposure amount. Then, a thin first cured layer A is formed. When the next layer is a layer corresponding to a portion that does not require accuracy, the Z-axis direction moving distance of the modeling base plate 3 to which the first hardened layer A is bonded is relatively large as shown in FIG. At the same time, the amount of light from the light source 12a is increased to irradiate a large amount of light energy (intensity), thereby changing the critical exposure amount to the resin. As a result, the solidification depth is increased, and a thick cured layer A2 is laminated as shown in FIG. When the thickness of the third layer is also increased, the movement distance of the modeling base plate 3 in the Z-axis direction may be increased as illustrated.
[0036]
In the case where the irregularities or voids have a shape that does not penetrate in the thickness direction of the optical structure, the micromirror of the mirror device 14 is turned on at the stage of forming the corresponding layer, and the light source 12a Irradiate light and collect it with a fine lens 90. Therefore, a complicated shape can be easily formed by stereolithography.
When a thin sheet-shaped stereolithographic object is obtained, the first layer may be used as a completed product.
[0037]
The present invention uses a mirror device 14, such as a digital micromirror device, and does not use a liquid crystal mask. For this reason, since all the light is reflected, the light is hardly heated, and the generation of heat due to the absorption of the light by the liquid crystal as in the case of a liquid crystal mask and the failure due to the heat can be prevented.
[0038]
【The invention's effect】
According to the first and fourth aspects of the present invention described above, an excellent effect is obtained that an extremely thin optical molded article having a thickness of, for example, 20 μm or less can be easily formed in a short time.
According to the second aspect, an excellent effect is obtained that it is possible to easily form a three-dimensionally stacked high-precision optically formed object having a small thickness in a short time.
According to the third aspect, when there is a portion having low accuracy and a portion requiring high accuracy in one modeled product, an excellent effect that it can be efficiently created in a short time is obtained.
[0039]
According to claim 5, since the digital micromirror device is used, all the light is reflected and less heated, and the heat is absorbed by the liquid crystal as in the case of the liquid crystal mask. An excellent effect is obtained in that generation and failure due to the occurrence can be avoided, and a shape to be formed by turning on / off the micromirror can be freely created.
According to the sixth and seventh aspects, it is possible to provide an apparatus capable of easily forming a three-dimensionally stacked high-precision optically shaped object with a relatively small size and a simple structure in a short time. Excellent effect can be obtained.
According to the eighth aspect, an excellent effect is obtained in that the cured product for lamination is easily peeled off.
[Brief description of the drawings]
FIG. 1 is a vertical sectional side view showing an example of a thin-film curing type stereolithography method and apparatus according to the present invention.
FIG. 2 is a perspective view of a molding state.
FIGS. 3A and 3B are plan views each showing an example of a main optical system.
FIG. 4 is a side view of a state in which modeling is performed using a Kepler beam expander as an intermediate optical system.
FIG. 5 is a partially enlarged view of FIG. 4;
FIG. 6 is a side view of a state in which modeling is performed using a Galileo beam expander as an intermediate optical system.
FIG. 7 is a partially enlarged view of FIG. 6;
FIG. 8 is a perspective view showing an outline of a digital micromirror device.
FIG. 9 is a side view showing a first example of a mode of forming a condensed spot.
FIG. 10 is a side view showing a second example of a mode of forming a condensed spot.
FIG. 11 is a side view showing a third example of a mode of forming a condensed spot.
FIG. 12 is a side view showing a fourth example of a mode of forming a condensed spot.
13 (a), (b) and (c) are schematic sectional views showing stepwise a thin film forming process in the present invention.
14 (a) and (b) are schematic plan views showing step by step the thin film forming process in the present invention.
FIGS. 15 (a), (b), (c) and (d) are schematic plan views showing stepwise a thin film forming process in the present invention.
FIGS. 16A and 16B are schematic cross-sectional views showing the lamination method in the present invention step by step.
17A and 17B are schematic cross-sectional views showing stepwise examples of the lamination method in the present invention.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 resin molding tank 2 photo-curable resin 3 molding base plate 4 Z-axis stage 6 YY-axis stage 9 main optical system 90 micro lens 11 intermediate optical system 14 mirror device

Claims (9)

A light shaping method by a regulated liquid level method of irradiating light energy to the photocurable resin in the tank from below the resin tank, and forming a resin cured material layer on the lower surface of the shaping base plate arranged in the resin liquid, Using a lens group in which a large number of fine lenses having a focal point very close to the lens surface are arranged, the light from the light source is condensed and irradiated on the lens group corresponding to a desired shape to be cured, and the light-curable resin is spot-shaped. A thin film curing type optical shaping method characterized in that a light spot is sequentially moved in an X direction or a Y direction to connect the spot-shaped cured portions in a plane to form a one-layer thin film. After forming the thin film by connecting the spot-shaped cured parts in a plane, the thin film is moved upward, and the light-curable resin under the thin film is focused and irradiated on the lens group to cure the light-curable resin into a spot shape The thin film curing according to claim 1, wherein the step of connecting the spot-shaped cured portions in a plane by sequentially moving the light spot in the X direction or the Y direction to form and laminate the next layer film is repeated one or more times. Mold stereolithography. 3. The thin-film curing type stereolithography method according to claim 2, including a case where the thickness of the lamination is changed. 2. A fine lens having a focal point very close to the lens surface and having a diameter of 300 microns or less and a light focal length of 20 microns or less from the surface of the transparent plate in contact with the photocurable resin. Thin film curing type stereolithography method. A digital micromirror device is used as a means of irradiating light to a lens group in which a large number of fine lenses having a focal point very close to the lens surface are arranged, and on / off of the micromirror group is selected to reduce the number of lenses. 5. The thin-film curing type optical shaping method according to claim 1, wherein a plurality of photo-curable resins are spot-cured by the corresponding focal points, and then the focal points are moved in parallel by a pitch of the lens to form a thin film. The bottom is made to store the photocurable resin in a resin tank made of a transparent plate, the modeling base plate placed in the resin tank is brought close to the transparent plate, and light is applied to the resin in the resin tank from below the resin tank. A light shaping apparatus using a regulated liquid surface method for irradiating and shaping a cured layer having a predetermined thickness on the lower surface of the shaping base plate, wherein a multi-point condensing spot lens using a fine lens having a focal point near the lens surface And a digital micromirror device for irradiating light from a light source as parallel light corresponding to a fine lens constituting the main optical system, and the optical system sequentially in the X direction or the Y direction. A thin-film curing type optical shaping apparatus comprising: means for moving; and means for moving a modeling base plate in a vertical direction. 7. The thin-film curing type optical shaping apparatus according to claim 6, wherein the lens of the main optical system has a diameter of 300 microns or less and a focal length of light of 20 microns or less from the surface of the transparent plate in contact with the photocurable resin. An intermediate optical system comprising a lens between the digital micromirror device and the main optical system, wherein the intermediate optical system includes a lens that outputs parallel light from the mirror device as parallel light expanded according to the pitch of the main optical system. 7. The thin film curing type stereolithography apparatus according to 6. 7. The thin-film curing type optical shaping apparatus according to claim 6, wherein a thin film such as Teflon or diamond-like carbon is stretched on a transparent plate as a release film.

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