JP2009160859A - Optical shaping apparatus, optical shaping method, and optically shaped article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shape a high accuracy shaped article at high strength. <P>SOLUTION: A package exposure optical system 12 and a beam scanning optical system 13 expose an ultraviolet curable resin 51 every small work domain which is a division of a whole work domain wherein optical shaping work is carried out into a plurality of domains. A control part 17 controls the package exposure optical system 12 and the beam scanning optical system 13 every rank of a curing layer. In relation to the boundary between the small work domains in a prescribed curing layer, the boundary between the small work domains in the next curing layer to be laminated on a prescribed curing layer is made a dislocated position seen in the lamination direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical modeling apparatus, an optical modeling method, and an optical modeling object, and in particular, relates to an optical modeling apparatus, an optical modeling method, and an optical modeling object that are capable of modeling a highly accurate modeling object with high strength. .

  Conventionally, when creating a three-dimensional model (modeled object) using three-dimensional shape data created by CAD (Computer Aided Design), for example, a numerically controlled machining machine or the like is used. Is created.

  In recent years, a technique called rapid prototyping (RP: Rapid Prototyping) for creating a three-dimensional model without machining has attracted attention in many manufacturing sites. Rapid prototyping is called additive manufacturing, in which a thin plate with a cross-sectional shape obtained by slicing a three-dimensional model is created based on the three-dimensional shape data of the three-dimensional model, and a three-dimensional model is created by stacking the thin plates with the cross-sectional shape. Manufacturing techniques are used.

  Rapid prototyping is based on the method of creating a thin plate having a cross-sectional shape, such as stereolithography using an ultraviolet curable resin, extrusion lamination of thermoplastic resin (FDM), powder melt adhesion lamination (SLS), paper Are classified into a thin film stacking method (LOM), a method of discharging powder and a curing catalyst and laminating (Ink-Jet method).

  For example, in stereolithography, 3D shape data of a stereo model created by CAD is converted into STL (Stereo Lithography), which is a format in which the surface of the stereo model is represented by a small triangular surface, and the stereolithography device Is input.

  The stereolithography apparatus creates cross-sectional shape data obtained by slicing a three-dimensional model from the three-dimensional shape data, for example, at regular intervals of about 0.1 to 0.2 mm, and the surface of the liquid photo-curing resin according to the cross-sectional shape data. The irradiation area of the light to be irradiated is determined. The stereolithography apparatus irradiates the surface of the liquid photocurable resin with light of the irradiation region corresponding to the cross sectional shape data for each layer of the cross sectional shape data, and a moving gantry in the liquid photocurable resin. The three-dimensional model is moved vertically downward according to the sliced thickness. Then, the stereolithography apparatus generates a three-dimensional model by repeating the light irradiation and the movement of the movable frame from the lowermost layer to the uppermost layer of the cross-sectional shape data.

  In stereolithography equipment, the light curable resin surface is irradiated with light using a beam scanning system that scans the light beam or a spatial light modulator (SLM: Spatial Light Modulator) such as a liquid crystal panel. There are SLM projection methods that irradiate the light, and a combination of a beam scan method and an SLM projection method.

  In the method combining the beam scan method and the SLM projection method, a spatial light modulator is used to collectively irradiate light onto the exposure area of the surface of the photocuring resin, and then the light beam is applied to the contour line of the cross-sectional shape data. By scanning along, it is possible to form a three-dimensional model in which the contour is formed cleanly in a short time.

  Here, Patent Literature 1 discloses an optical modeling apparatus that can adjust the distance between a mirror for scanning a light beam and the surface of a photo-curing resin in accordance with the size of a three-dimensional model.

Japanese Patent Laid-Open No. 5-77323

  Although the optical modeling apparatus is configured as described above, there has been a demand for modeling a model with higher accuracy than before with high strength.

  This invention is made | formed in view of such a condition, and enables it to model a highly accurate molded article with high intensity | strength.

  The optical modeling apparatus according to one aspect of the present invention is configured to form the cured layer by irradiating the surface of the photocurable resin with light according to the cross-sectional shape data of the optical modeled object, and stack the cured layer to form the optical modeling. An optical modeling apparatus for modeling an object, wherein an exposure unit that exposes the photocurable resin for each small work area obtained by dividing an entire work area in which optical modeling work is performed into a plurality of areas, and the exposure means Control for each layer of the hardened layer, with respect to the boundary between the work small areas in the predetermined hardened layer, the boundary between the work small areas in the next hardened layer laminated on the predetermined hardened layer, Exposure control means for making the position shifted from the stacking direction.

  The optical modeling method according to one aspect of the present invention is such that the optical modeling is performed by irradiating the surface of the photocurable resin with light according to the cross-sectional shape data of the optical modeling object to form a cured layer, and laminating the cured layer. An optical modeling method for modeling an object, exposing the photocurable resin for each work small area obtained by dividing an entire work area in which an optical modeling work is performed into a plurality of areas, and in the predetermined cured layer The step of setting the boundary between the small work areas in the next hardened layer laminated on the predetermined hardened layer to a position shifted from the stacking direction with respect to the boundary between the small work areas.

  An optically shaped object according to one aspect of the present invention is an optically shaped object that is shaped by irradiating the surface of the photocurable resin with light according to cross-sectional shape data to form a cured layer and laminating the cured layer. The photocurable resin is exposed for each work small region obtained by dividing the entire work region where the optical modeling work is performed into a plurality of regions, and the boundary between the work small regions in the predetermined hardened layer Thus, the boundary between the small work areas in the next hardened layer laminated on the predetermined hardened layer is formed at a position shifted from the stacking direction.

  In one aspect of the present invention, the photocurable resin is exposed for each work small area obtained by dividing the entire work area in which the optical modeling work is performed into a plurality of areas, and at a boundary between the work small areas in a predetermined hardened layer. On the other hand, the boundary between the small work areas in the next hardened layer laminated on the predetermined hardened layer is set to a position shifted from the stacking direction.

  According to one aspect of the present invention, a highly accurate model can be modeled with high strength.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.

  First, with reference to FIG. 1, the tiling method which is the method of optical modeling in the optical modeling apparatus to which this invention is applied is demonstrated.

  Generally, in stereolithography, the contour of a three-dimensional model can be formed with high accuracy by reducing the range of scanning a light beam or the range of irradiating light using a spatial light modulator. The dimensional accuracy of the three-dimensional model can be improved. Therefore, for example, a tiling method has been proposed in which the entire work area, which is the entire area where the optical modeling work is performed, is divided into a plurality of small work areas, and batch exposure and beam scanning are performed for each small work area.

  FIG. 1A shows the entire work area, and FIG. 1B shows a small work area that is a part of the entire work area.

  In FIG. 1, the vertical and horizontal dimensions of the entire work area are 10 cm × 10 cm, and the vertical and horizontal dimensions of the small work area are 1 cm × 1 cm. That is, the entire work area is divided into 10 × 10 small work areas in the vertical and horizontal directions.

  As shown in FIG. 1A, the hatched area near the center of the entire work area is the exposure area corresponding to the cross-sectional shape data of the three-dimensional model, and is the second line from the bottom of the entire work area. The work small area in the third column from the left is enlarged and shown in FIG. 1B.

  Here, in the batch exposure, assuming that a spatial light modulator having 1000 pixels × 1000 pixels in the vertical and horizontal directions is used, as shown in FIG. Accordingly, the vertical × horizontal is divided into 1000 × 1000 unit regions (that is, a region corresponding to one pixel of the spatial light modulator). Since the vertical and horizontal dimensions of the work small area are 1 cm × 1 cm, the vertical and horizontal dimensions of the unit area are 10 μm × 10 μm.

  In FIG. 1B, the contour line of the cross-sectional shape data is represented by a two-dot chain line, and the unit area exposed by the batch exposure is hatched. That is, in the batch exposure, the unit region inside the contour line is exposed, and the unit region where the contour line of the cross-sectional shape data overlaps and the unit region outside the contour line of the cross-sectional shape data are not exposed. .

  After the collective exposure is performed, a beam scan is performed along the inside of the contour line of the cross-sectional shape data, and an area inside the contour line that is not exposed by the collective exposure is exposed.

  Here, generally, the strength of the hardened layer decreases at the boundary of the work small region. That is, the strength at the bonding position where the ultraviolet curable resin (hereinafter, appropriately referred to as a tile) of the size of the workpiece small region cured by exposing the workpiece small region is joined to the strength of the tile. Lower. In particular, when the boundaries of the work subregions coincide with each other in each hardened layer, that is, when the joining positions of tiles are continuous in the stacking direction of each hardened layer, the overall strength of the shaped article may be reduced. is there. For example, it becomes easy to produce the crack which goes to a lamination direction in a junction position.

  With reference to FIG. 2, a description will be given of a decrease in strength of a shaped object due to continuous joining positions of tiles in the stacking direction.

  FIG. 2 shows a modeled object viewed from the Y direction when the plane along the hardened layer is the XY plane and the direction in which the hardened layer is laminated is the Z direction. The modeled object shown in FIG. 2 is configured by laminating four layers in the Z direction, which are formed by bonding four tiles in the X direction.

  As shown in FIG. 2, in the molded object, the bonding positions of the tiles are continuous in the Z direction in the first to fourth hardened layers. That is, the joint positions of the tiles of the first to fourth hardened layers overlap each other when viewed from the Z direction. In such a modeled object, for example, in the region surrounded by a broken line, the joining position of each tile is continuous from the upper surface to the bottom surface, so that a crack is generated at the bonding position and the modeled object is damaged. .

  Therefore, in the stereolithography apparatus to which the present invention is applied, the joining positions of the tiles of the respective hardened layers are shifted from the Z direction so that such damage does not occur.

  FIG. 3 is a block diagram showing a configuration example of an embodiment of an optical modeling apparatus to which the present invention is applied.

  In FIG. 3, the optical modeling apparatus 11 includes a batch exposure optical system 12, a beam scan optical system 13, a polarization beam splitter 14, an objective lens 15, a work unit 16, and a control unit 17, and is an ultraviolet ray that is a photocurable resin. Stereolithography is performed by irradiating the cured resin 51 with light (ultraviolet rays). In FIG. 3, illustration of a part of lines representing that the control unit 17 controls each block constituting the optical modeling apparatus 11 is omitted because the figure becomes complicated.

  The collective exposure optical system 12 is an optical system for performing collective exposure to collectively expose the surface of the ultraviolet curable resin 51 in the work part 16, and includes a light source 21, a shutter 22, a polarizing plate 23, a beam integrator 24, and a mirror. 25, a spatial light modulator 26, and a condenser lens 27.

  As the light source 21, for example, a high-power blue LED arranged in an array can be used, and the light source 21 emits light for performing batch exposure. As the light source 21, it is not necessary to use a coherent laser light source.

  The shutter 22 controls the passage or shielding of the light emitted from the light source 21 according to the control of the control unit 17, and controls on / off of the exposure by the collective exposure optical system 12.

  The polarizing plate 23 uses light that has passed through the shutter 22 as predetermined polarized light. That is, the polarizing plate 23 polarizes the light so that the spatial light modulator 26 composed of a transmissive liquid crystal panel can spatially modulate the light from the light source 21.

  The beam integrator 24 makes the light polarized by the polarizing plate 23 uniform. As the beam integrator 24, a general type such as a fly-eye type in which a plurality of lens elements are arranged, or a light rod type in which the inside of a columnar rod lens such as a square column is totally reflected is used.

  The mirror 25 reflects the light uniformed by the beam integrator 24 toward the spatial light modulator 26.

  The spatial light modulator 26 is composed of, for example, a transmissive liquid crystal panel, and the light reflected by the mirror 25 exposes an irradiation area corresponding to the cross-sectional shape data on the ultraviolet curable resin 51. According to the control, a part of the light is spatially modulated.

  That is, a drive signal for driving each pixel of the liquid crystal panel is supplied from the control unit 17 to the spatial light modulator 26 according to the cross-sectional shape data, and the spatial light modulator 26 performs irradiation based on the drive signal. The direction of polarized light to be transmitted is changed by changing the arrangement of the liquid crystal molecules of the pixel corresponding to the region. As a result, the spatial light modulator 26 spatially modulates the light passing through the liquid crystal panel, and uses the region corresponding to one pixel of the liquid crystal panel as a unit region for exposure, and converts light having a shape corresponding to the cross-sectional shape data to ultraviolet light. Projected onto the cured resin 51.

  The condenser lens 27 is composed of a lens group for correcting distortion when the light spatially modulated by the spatial light modulator 26 passes through the objective lens 15, and the light spatially modulated by the spatial light modulator 26. Is focused on the front focal point of the objective lens 15 on the reflection / transmission surface of the polarization beam splitter 14. For example, the distortion can be reduced by configuring each lens group so that the condenser lens 27 and the objective lens 15 are symmetrical optical systems.

  The beam scan optical system 13 is an optical system for performing a beam scan exposure by scanning the surface of the ultraviolet curable resin 51 of the work part 16 with a laser beam, and includes a light source 31, a collimator lens 32, an anamorphic lens 33, a beam. An expander 34, a beam splitter 35, a shutter 36, galvanometer mirrors 37 and 38, relay lenses 39 and 40, and a reflected light monitor unit 41 are included.

  The light source 31 is, for example, a semiconductor laser that emits a laser beam having a relatively short wavelength in the blue to ultraviolet range, and emits a light beam for performing a beam scan by the beam scan optical system 13. As the light source 31, a gas laser or the like may be used in addition to the semiconductor laser.

  The collimator lens 32 converts the divergence angle of the light beam emitted from the light source 31 into substantially parallel light. The anamorphic lens 33 shapes the elliptical light beam that has been made substantially parallel light by the collimator lens 32 into a substantially circular shape.

  The beam expander 34 changes the beam diameter (beam diameter) of the light beam formed into a substantially circular shape by the anamorphic lens 33 to a desired beam diameter suitable for the aperture, NA (numerical aperture), and the like of the objective lens 15. Convert to adjust the beam size.

  The beam splitter 35 transmits the light beam emitted from the light source 31 and directs it toward the ultraviolet curable resin 51 in the work part 16, and is reflected by the ultraviolet curable resin 51 and returns to each optical system. Is reflected toward the reflected light monitor unit 41.

  The shutter 36 controls the passage or shielding of the light beam transmitted through the beam splitter 35 according to the control of the control unit 17, and controls on / off of the beam scan exposure by the beam scan optical system 13. When the light source 31 is a semiconductor laser, it is possible to control the on / off of the beam scan exposure by directly modulating the radiation of the light beam in the semiconductor laser, so that the beam scan optical system without providing the shutter 36. 13 may be configured.

  The galvanometer mirrors 37 and 38 have reflecting means that can rotate in a predetermined direction, and adjusting means that adjusts the angle of the rotating direction of the reflecting means in accordance with an electric signal. The adjusting means adjusts the angle of the reflecting means. By adjusting, the light beam reflected by the reflecting means is scanned in a predetermined direction.

  That is, the galvanometer mirror 37 reflects the light beam that has passed through the shutter 36 toward the galvanometer mirror 38, and in the X direction that is a predetermined direction in a plane parallel to the liquid surface that is the surface of the ultraviolet curable resin 51. To scan. The galvanometer mirror 38 reflects the light beam reflected by the galvanometer mirror 37 toward the polarization beam splitter 14 and is a direction orthogonal to the X direction in a plane parallel to the liquid surface that is the surface of the ultraviolet curable resin 51. Scan in the Y direction.

  The relay lenses 39 and 40 are formed of a lens group having one or a plurality of lenses, and emit parallel incident light beams in parallel over a scan angle at which the light beams are scanned by the galvanometer mirrors 37 and 38. In other words, the relay lens 39 forms an image of the light beam reflected by the galvano mirror 37 on the galvano mirror 38, and the relay lens 40 reflects the light beam reflected by the galvano mirror 38 by the polarization beam splitter 14. The image is formed on the surface.

  As described above, the relay lens 39 is provided between the galvanometer mirror 37 and the galvanometer mirror 38, and the relay lens 40 is provided between the galvanometer mirror 38 and the polarization beam splitter 14. Even if the light beam is scanned by the mirror 37 and the galvanometer mirror 38, the light beam can be imaged on the reflection / transmission surface of the polarization beam splitter 14 and combined with the light from the collective exposure optical system 12.

  The reflected light monitor unit 41 detects the return light reflected by the surface of the ultraviolet curable resin 51 using, for example, an astigmatism method or a triangulation method. The return light detected by the reflected light monitor unit 41 is used for focus adjustment of a light beam irradiated from the beam scan optical system 13 to the ultraviolet curable resin 51. For example, based on the return light detected by the reflected light monitor unit 41, the plurality of lenses included in the beam expander 34 are driven to adjust the size of the beam diameter, or the parallel of the light beam transmitted through the beam expander 34. A lens for adjusting the degree can be provided, and the size of the beam diameter can be adjusted by the lens. Further, by moving the spatial light modulator 26 and the objective lens 15 in the optical axis direction based on the return light detected by the reflected light monitor unit 41, the light imaged on the ultraviolet curable resin 51 in the batch exposure is displayed. The focus can be adjusted.

  The polarization beam splitter 14 combines the light from the collective exposure optical system 12 and the light beam from the beam scan optical system 13 and guides the light to the ultraviolet curable resin 51. The polarizing beam splitter 14 is disposed such that its reflection / transmission surface coincides with the front focal position of the objective lens 15.

  The objective lens 15 includes a lens group having one or a plurality of lenses. The light from the batch exposure optical system 12 is imaged on the surface of the ultraviolet curable resin 51 and the light beam from the beam scan optical system 13 is condensed. To do.

  Further, the objective lens 15 is arranged so that the light beam deflected by the galvanometer mirrors 37 and 38 of the beam scanning optical system 13 is scanned at a constant speed on the surface of the ultraviolet curable resin 51, that is, the surface of the ultraviolet curable resin 51. The scanning is performed at a uniform scanning line speed.

  For example, the objective lens 15 has a so-called fθ having an image height Y proportional to the incident angle θ and a product (Y = f × θ) where the product of the focal length f and the incident angle θ becomes the image height Y. A lens is used. In other words, the fθ lens is a lens designed so that the scanning speed of the scanned light beam is always constant regardless of the incident position on the lens. By using such an objective lens 15, it is possible to prevent a difference between the design shape due to the variation in the scanning linear velocity and the actual shape of the hardened layer, thereby realizing high-definition modeling.

  The work unit 16 includes a storage container 52, a stage 53, and a drive unit 54.

  The storage container 52 stores the liquid ultraviolet curable resin 51.

  The stage 53 is immersed in the ultraviolet curable resin 51 of the storage container 52, and is perpendicular to the liquid surface, which is the surface of the ultraviolet curable resin 51 (in the direction of arrow Z in FIG. 2), and the direction along the liquid surface. That is, it can move in the XY direction perpendicular to the direction of the arrow Z.

  The drive unit 54 drives the storage container 52 and the stage 53 according to the control of the control unit 17. For example, the drive unit 54 moves the stage 53 in the XY direction for each small work area (FIG. 1) where exposure is performed, and the stage 53 is stepped one step each time one hard layer of the three-dimensional model is formed. Is moved downward in the Z direction according to the thickness of the hardened layer (thickness d in FIGS. 2 and 4). The drive unit 54 drives the container 52 in the vertical direction so that the surface of the ultraviolet curable resin 51 coincides with the rear focal position of the objective lens 15.

  The control unit 17 controls the light source 21 to turn on / off light emission from the light source 21, controls the shutter 22 to turn on / off the exposure of the ultraviolet curable resin 51, and controls the drive unit 54. The container 52 and the stage 53 are driven by controlling. Further, the control unit 17 drives each pixel of the spatial light modulator 26 so that the pixel of the spatial light modulator 26 corresponding to the irradiation area transmits light based on the cross-sectional shape data of the three-dimensional model. Is supplied to the spatial light modulator 26.

  Here, when the control unit 17 generates the work small area data by dividing the cross-sectional shape data of the three-dimensional model for each work small area (FIG. 1), the work small area of the solid layer is directly stacked. The work small area data is generated so that the boundary does not coincide, that is, the tile joining position is shifted from the stacking direction. Then, each part of the optical modeling apparatus 11 is controlled so that the ultraviolet curable resin 51 is exposed for each work small region based on the work small region data generated as described above.

  With reference to FIG. 4 and FIG. 5, the example of the optical modeling thing shape | molded so that the joining position of a tile may become a position shifted from the lamination direction is demonstrated.

  FIG. 4 shows a modeled object viewed from the Y direction as in FIG.

  4, the first and third hardened layers are formed by joining four tiles in the X direction, and the second and fourth hardened layers are in the X direction. Three tiles are bonded, and half-length tiles are bonded to both ends thereof. That is, if the length of the tile in the X direction is Lx, the second and fourth hardened layers are provided with tiles having a length Lx / 2 at both ends.

  In the modeled object formed in this way, the first to fourth hardened layers are each half of the tile position (joint position between the tiles) of the tiles in the directly laminated hardened layers. The position is shifted by this amount.

  Therefore, in the region surrounded by the broken line as in FIG. 2, the joint position of the tile does not continue in the shaped object of FIG. 4, and in this region, the tile is formed with the first and third hardened layers. The decrease in strength due to the joining position is reinforced by the tiles of the second and fourth hardened layers, and cracks in the Z direction are less likely to occur in this region than in the case of FIG. That is, the strength of the modeled object of FIG. 4 is improved in the same manner as the effect of improving the strength by alternately stacking bricks in a general building or the like.

  FIG. 5 shows the hardened layer viewed from the Z direction.

  FIG. 5A shows the first and third hardened layers, and FIG. 5B shows the second and fourth hardened layers. As shown in FIG. 5, the tiles of the first and third hardened layers and the tiles of the second and fourth hardened layers are shifted by Lx / 2 in the X direction and in the Y direction. Ly / 2 (where Ly is the length of the tile in the Y direction) is shifted.

  Further, the point P and the point P ′ shown in FIG. 5 are generated when the control unit 17 (FIG. 3) generates the work small area data by dividing the cross-sectional shape data of the three-dimensional model for each work small area. The point P and the point P ′ are deviated from each other by Lx / 2 in the X direction and Ly / 2 in the Y direction. Further, the point P is set so as to coincide with the lower left vertex of the entire work area (in FIG. 5, the hardened layer is formed on the entire work area).

  Then, in the first and third layers, the control unit 17 generates work small area data using the point P, which is the lower left vertex of the entire work area, as a reference point, and in the second and fourth layers, the entire work area is generated. Work small area data is generated with a point P ′ shifted from the lower left apex of the area by a half of one side of the tile as a reference point. Further, the control unit 17 controls the driving unit 54 when performing the exposure process so that the exposure based on the work small area data based on the point P is performed in the first layer and the third layer. The stage 53 is driven, and in the second and fourth layers, the stage 53 is driven so that exposure based on the work small area data with reference to the point P ′ is performed.

  Next, FIG. 6 is a flowchart illustrating a process for performing optical modeling by the optical modeling apparatus 11.

  For example, when the three-dimensional shape data of the three-dimensional model created by CAD is input to the optical modeling apparatus 11 and an operation for starting the optical modeling is performed, in step S11, the control unit 17 causes the three-dimensional model created by CAD. A program for converting the three-dimensional shape data of the model into STL is executed, and the three-dimensional shape data of the stereo model is converted into STL.

  After the process of step S11, the process proceeds to step S12, and the control unit 17 creates cross-sectional shape data of the three-dimensional model from the three-dimensional shape data converted into STL, and the process proceeds to step S13. Further, when creating the cross-sectional shape data of the three-dimensional model, for example, the posture and orientation of the three-dimensional model are determined, and data for modeling a member for preventing the falling of the three-dimensional model during modeling is created. .

  In step S13, the control unit 17 sets 1 as an initial value to the number n of layers indicating the layer of the cured layer to be processed, and the process proceeds to step S14.

  In step S14, the control unit 17 performs processing for creating work small area data (processing in step S15) and processing for exposing the work small area (processing in step S16) for a point P that coincides with the lower left vertex of the entire work area. In the processing), the reference point is set as a reference, and the processing proceeds to step S15.

  In step S15, the control unit 17 sets the n-th layer cross-sectional shape data to be processed as the reference point set in step S14 (or the point P set as the reference point in step S20 described later). ') Is used as a reference to create (generate) work small area data, and the process proceeds to step S16.

  In step S16, the control unit 17 sequentially exposes the work small regions based on the points set as the reference points according to the work small region data generated in step S15, and all the workpieces in the nth layer cross-sectional shape data are exposed. When exposure is performed according to the small area data, the process proceeds to step S17.

  In step S17, the control unit 17 determines whether or not exposure based on all the cross-sectional shape data created in step S12 has been performed.

  If the control unit 17 determines in step S17 that exposure based on all cross-sectional shape data has not been performed, the process proceeds to step S18.

  In step S <b> 18, the control unit 17 increments the number n of layers by 1 and sets the next hardened layer as a processing target.

  After the process of step S18, the process proceeds to step S19, where the reference point of the (n-1) th layer is the point P that coincides with the vertex or the point P ′ that is shifted from the vertex by half the length of one side of the tile. Determine which was.

  In step S19, when the control unit 17 determines that the reference point of the (n-1) th layer is the point P, the process proceeds to step S20. In step S20, the control unit 17 sets the point P ′ as a reference point which becomes a reference in the process of creating the work small area data and the process of exposing the work small area, and the process proceeds to step S15. Similar processing is repeated.

  On the other hand, when the control unit 17 determines in step S19 that the reference point of the (n−1) th layer is the point P ′, the process proceeds to step S14, and the same process is repeated thereafter.

  On the other hand, when the control unit 17 determines in step S17 that the exposure based on all the cross-sectional shape data has been performed, the three-dimensional model is completed, and the process ends.

  As described above, in the stereolithography apparatus 11, the reference point for creating the work small area data and the reference point for exposing the work small area are the point P and the point P ′ for each layer of the hardened layer. By alternately setting at, the boundaries between the small work areas are shifted from each other as seen from the Z direction. As a result, as described with reference to FIG. 4, since the tile joining position is shifted, the strength of the modeled object can be improved.

  In stereolithography, the photocuring resin shrinks when it is cured, and the shrinkage causes warping at the end of the tile, which may distort the modeled object, but the tile joining position is shifted. Thus, the end of the tile is held down by the upper and lower tiles, so that such warpage is suppressed. Therefore, distortion of a modeled object is suppressed and it can model with high precision.

  By using such an optical modeling apparatus 11, prototypes of microchips, connectors, microcapsules, etc., or various fine parts can be modeled. And, for example, since the modeled object modeled using the optical modeling apparatus 11 is modeled with high strength, when plating with nickel or the like and transferring the mold, cracks are generated in the stacking direction. There is no.

  In this embodiment, an fθ lens is used as the objective lens 15, but a lens having a normal condensing function can be used as the objective lens 15. In this case, the beam scanning optical system 13 is configured to scan the light beam at a uniform scanning line speed by controlling the rotational speed of the galvanometer mirrors 37 and 38. In addition to the galvanometer mirrors 37 and 38, a polygon mirror or the like may be used as means for scanning the light beam.

  Furthermore, as the spatial light modulator 26, in addition to a transmissive liquid crystal panel, a digital micromirror device (DMD) formed by arranging a plurality of minute reflecting mirrors whose inclination angle changes according to an input signal, Alternatively, a reflective liquid crystal element (LCOS: Liquid Crystal On Silicon) or the like may be used. When a digital micromirror device is used, each micromirror corresponds to one unit region, and the collective exposure optical system 12 can be configured without providing the polarizing plate 23.

  Further, the amount of shifting the tile joining position for each hardened layer is not limited to 1/2 of the length of one side of the tile. For example, the joining position is shifted by 1/3 of the length of one side of the tile. It can also be done. In addition, the direction of shifting the tile joining position is not only shifted alternately in the X direction and the Y direction, but for example, with respect to the reference cured layer, the next cured layer is shifted only in the X direction, and the next cured layer. Then, it may be shifted only in the Y direction, and the next hardened layer may be repeatedly matched with the hardened layer serving as a reference.

  Needless to say, the workpiece small region is not limited to a square, and the dimension in the X direction may be different from the dimension in the Y direction.

  In addition to the optical modeling apparatus 11 that performs optical modeling by the free liquid surface method, which is a method of irradiating the light spatially modulated by the spatial light modulator 17 from above the ultraviolet curable resin 51, for example, the space It can be applied to an optical modeling apparatus that performs optical modeling by a regulated liquid surface method, which is a method of irradiating the light spatially modulated by the light modulator 26 to the interface between the ultraviolet curable resin 51 and the container 52.

  For example, the bottom surface of the storage container 52 is made of a material that transmits light, such as glass, and the light spatially modulated by the spatial light modulator 26 at the interface between the glass and the ultraviolet curable resin 51 is below the ultraviolet curable resin 51. Irradiated from. That is, the surface of the ultraviolet curable resin 51 to which light corresponding to the cross-sectional shape data of the three-dimensional model is irradiated includes glass, the ultraviolet curable resin 51 and the interface.

  In the regulated liquid level method, the stage 53 is arranged so that the distance between the storage container 52 and the stage 53 is equal to the thickness of the cured layer for one layer, and the ultraviolet curable resin 51 is irradiated through the glass on the bottom surface of the storage container 52. By repeating the process of driving the stage 53 upward in the vertical direction so that the thickness of the hardened layer for one layer is formed step by step as the hardened layer of the three-dimensional model is formed by the applied light. A three-dimensional model is formed.

  Thus, by regulating the surface (interface) of the ultraviolet curable resin 51 irradiated with light with glass, the thickness of one layer of the cured layer is accurately modeled, so that the lamination accuracy can be improved. Thus, the three-dimensional model can be formed with high accuracy.

  The series of processes performed by the control unit 17 described above can be executed by hardware or can be executed by software. When a series of processing is executed by software, a program constituting the software executes various functions by installing a computer incorporated in dedicated hardware or various programs. For example, it is installed from a program recording medium in a general-purpose personal computer or the like.

  FIG. 7 is a block diagram showing an example of the hardware configuration of a computer that executes the above-described series of processing by a program.

  In a computer, a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, and a RAM (Random Access Memory) 103 are connected to each other via a bus 104.

  An input / output interface 105 is further connected to the bus 104. The input / output interface 105 includes an input unit 106 including a keyboard, a mouse, and a microphone, an output unit 107 including a display and a speaker, a storage unit 108 including a hard disk and nonvolatile memory, and a communication unit 109 including a network interface. A drive 110 for driving a removable medium 111 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory is connected.

  In the computer configured as described above, the CPU 101 loads, for example, the program stored in the storage unit 108 to the RAM 103 via the input / output interface 105 and the bus 104 and executes the program. Is performed.

  The program executed by the computer (CPU 101) is, for example, a magnetic disk (including a flexible disk), an optical disk (CD-ROM (Compact Disc-Read Only Memory), DVD (Digital Versatile Disc), etc.), a magneto-optical disk, or a semiconductor. The program is recorded on a removable medium 111 that is a package medium including a memory or the like, or is provided via a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting.

  The program can be installed in the storage unit 108 via the input / output interface 105 by attaching the removable medium 111 to the drive 110. Further, the program can be received by the communication unit 109 via a wired or wireless transmission medium and installed in the storage unit 108. In addition, the program can be installed in the ROM 102 or the storage unit 108 in advance.

  The program executed by the computer may be a program that is processed in time series in the order described in this specification, or in parallel or at a necessary timing such as when a call is made. It may be a program for processing. Further, the program may be processed by a single CPU, or may be processed in a distributed manner by a plurality of CPUs.

  The embodiment of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

It is a figure explaining a tiling system. It is a figure explaining the fall of the intensity | strength of a molded article. It is a block diagram which shows the structural example of one Embodiment of the optical modeling apparatus to which this invention is applied. It is a figure which shows the example of the optical modeling thing shape | molded so that the joining position of a tile may turn into a position which seeed from the lamination direction. It is a figure which shows the example of the optical modeling thing shape | molded so that the joining position of a tile may turn into a position which seeed from the lamination direction. 5 is a flowchart for explaining processing for performing optical modeling by the optical modeling apparatus 11. It is a block diagram which shows the structural example of a computer.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 Stereolithography apparatus, 12 Collective exposure optical system, 13 Beam scanning optical system, 14 Polarization beam splitter, 15 Objective lens, 16 Work part, 17 Control part, 21 Light source, 22 Shutter, 23 Polarizing plate, 24 Beam integrator, 25 Mirror , 26 Spatial light modulator, 27 Condensing lens, 28 Drive unit, 31 Light source, 32 Collimator lens, 33 Anamorphic lens, 34 Beam expander, 35 Beam splitter, 36 Shutter, 37 and 38 Galvano mirror, 39 and 40 Relay lens, 41 reflected light monitor, 51 UV curable resin, 52 container, 53 drive unit

Claims (5)

In the optical modeling apparatus for modeling the optical modeling object by irradiating the surface of the photocurable resin with light according to the cross-sectional shape data of the optical modeling object, forming a cured layer, and laminating the cured layer,
An exposure unit that exposes the photocurable resin for each work small area obtained by dividing the entire work area where the optical modeling work is performed into a plurality of areas;
The exposure means is controlled for each layer of the hardened layer, and the work subregions in the next hardened layer stacked on the predetermined hardened layer with respect to the boundary between the work subregions in the predetermined hardened layer. An optical shaping apparatus comprising: an exposure control unit that causes the boundary of the position to be shifted from the stacking direction. The entire work area is divided into a grid by the rectangular work small areas,
The exposure control means is an abbreviation of a length of one side of the work small area, indicating a deviation between a boundary between the work small areas in the predetermined hardened layer and a boundary between the work small areas in the next hardened layer. The optical modeling apparatus according to claim 1, wherein the optical modeling apparatus is half. The exposure control means includes a boundary between the small work areas in the predetermined hardened layer and a boundary between the small work areas in the next hardened layer along two orthogonal sides of the small work area. The optical modeling apparatus according to claim 2, wherein the optical modeling apparatus is shifted in two directions. In the optical modeling method of modeling the optical modeling object by irradiating the surface of the photocurable resin with light according to the cross-sectional shape data of the optical modeling object to form a cured layer and laminating the cured layer,
Exposing the photocurable resin for each work small area obtained by dividing the entire work area where the optical modeling work is performed into a plurality of areas,
The step of setting the boundary between the work small regions in the next hardened layer laminated on the predetermined hardened layer to a position shifted from the stacking direction with respect to the boundary between the work small regions in the predetermined hardened layer Stereolithography method including In an optical modeling object that is shaped by irradiating the surface of the photocurable resin with light according to the cross-sectional shape data to form a cured layer and laminating the cured layer,
The photocurable resin is exposed for each work small area obtained by dividing the entire work area where the optical modeling work is performed into a plurality of areas,
The boundary between the work subregions in the next hardened layer to be laminated on the predetermined hardened layer is deviated from the stacking direction with respect to the boundary between the work subregions in the predetermined hardened layer. Modeled stereolithography.

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