JP2009137230A - Optical shaping apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately shape a precision three-dimensional model. <P>SOLUTION: A package exposure optical system 12 and a beam scanning optical system 13, according to three-dimensional model cross section shape data, irradiate the surface of an ultraviolet curing resin 51 with light per unit of an exposure small domain which is a prescribed rectangular domain. A driving part 54, when the x direction parallel to the surface of the ultraviolet curing resin 51 is different from the direction of one side of the exposure small domain, moves the exposure small domain in the x direction by a first distance and in the y direction parallel to the surface of the ultraviolet curing resin 51 by a second distance to scan the exposure small domain in the direction of one side of the exposure small domain. The present invention, for example, can be applied to an optical shaping apparatus. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical modeling apparatus, and more particularly to an optical modeling apparatus capable of modeling a higher-definition three-dimensional model with high accuracy.

  For example, there are a beam scanning method and a batch exposure method as an optical modeling method of a conventional optical modeling device using a photocurable resin.

  A beam scanning stereolithography apparatus has a beam scanning optical system that scans a light beam such as a laser beam emitted from a light source, and slices a three-dimensional shape of a three-dimensional model into a predetermined thickness in a stacking direction. Based on the data of the cross-sectional shape (hereinafter referred to as cross-sectional shape data), each cured layer is formed by drawing while scanning the photocurable resin layer by layer, and a three-dimensional model is formed by laminating them .

  The beam scanning stereolithography system can increase the definition of a three-dimensional model that can be modeled by changing the wavelength used and the lens system configuration and reducing the spot diameter. However, there is a limit to reducing the spot diameter. Therefore, the definition could not be increased sufficiently.

  In addition, the batch exposure optical modeling apparatus has a batch exposure optical system having a spatial light modulator (SLM (Spatial Light Modulator)) such as a liquid crystal panel or DMD (Digital Micromirror Device), and is based on cross-sectional shape data. The pattern of each layer displayed on the spatial light modulator is projected onto the photocurable resin to form each cured layer, and a three-dimensional model is formed by laminating them.

  In batch exposure system stereolithography equipment, it is possible to increase the definition of a stereo model that can be modeled by reducing the pixel size of the spatial light modulator, but the pixel size is limited. The degree could not be increased sufficiently.

Conventionally, there is an image recording apparatus that has an SLM and records an image on the PS plate by irradiating the PS plate with ultraviolet light modulated by the SLM (see, for example, Patent Document 1).
JP-A-6-95257

  As described above, the precision of a three-dimensional model that can be modeled cannot be sufficiently increased in a beam scanning type or batch exposure type optical modeling apparatus. Therefore, there has been a demand for an optical modeling apparatus that models a higher-definition three-dimensional model with high accuracy.

  The present invention has been made in view of such a situation, and makes it possible to form a higher-definition three-dimensional model with high accuracy.

  The stereolithography apparatus according to one aspect of the present invention is configured to irradiate the surface of the photocurable resin with light according to the cross-sectional shape data of the three-dimensional model to form a hardened layer, and stack the hardened layer, so In the optical modeling apparatus for modeling, an exposure means for irradiating light on the surface of the photocurable resin in units of a predetermined rectangular area according to the cross-sectional shape data, and a first parallel to the surface of the photocurable resin Moving means for moving the rectangular region in at least one of the first direction and the second direction, and the moving means moves in the first direction when the first direction is different from the one side direction. The rectangular region is scanned in the direction of the one side by moving the rectangular region by a first distance and moving the rectangular region by a second distance in the second direction.

  In the stereolithography apparatus according to one aspect of the present invention, when the first direction and the second direction are orthogonal to each other, the first distance and the second distance are set in the rectangular area by the collective exposure unit. Can be determined in accordance with the direction of one side of the test stereo model formed by irradiating and the angle between the first direction.

  In the optical modeling apparatus according to one aspect of the present invention, when the first direction and the second direction are not orthogonal, the light is applied to the rectangular region by the batch exposure unit for the first distance. And the second distance is determined according to an angle between the direction of the one side and the first direction, and the angle between the direction of the one side and the first direction, and , And can be determined according to an angle between the first direction and the second direction.

  In one aspect of the present invention, light is irradiated on the surface of the photocurable resin in units of a predetermined rectangular area according to the cross-sectional shape data, and the first direction parallel to the surface of the photocurable resin and the rectangular area When the direction of one side is different, the rectangular area is moved by the first distance in the first direction, and the rectangular area is moved by the second distance in the second direction parallel to the surface of the photocurable resin. Thus, the rectangular area is scanned in the direction of one side of the rectangular area.

  As described above, according to one aspect of the present invention, a higher-definition three-dimensional model can be formed. Further, according to one aspect of the present invention, a high-definition three-dimensional model can be modeled with high accuracy.

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

  FIG. 1 shows a configuration example of an embodiment of an optical modeling apparatus to which the present invention is applied.

  1 includes a batch exposure optical system 12, a beam scanning optical system 13, a polarization beam splitter 14, an objective lens 15, a drive unit 15A, and a work unit 16, and a workpiece according to the cross-sectional shape data. Stereolithography is performed by irradiating the ultraviolet curable resin 51, which is a liquid ultraviolet curable resin in the portion 16, with ultraviolet light.

  The batch exposure optical system 12 is an optical system for performing batch exposure that collectively exposes a predetermined rectangular region on the surface of the ultraviolet curable resin 51 in the work unit 16. The light source 21, the shutter 22, the polarizing plate 23, A beam integrator 24, a mirror 25, a spatial light modulator 26, a condenser lens 27, and a drive unit 28 are included.

  As the light source 21, for example, a high-power blue LED (Light Emitting Diode) arranged in an array can be used. Unlike the light source 31 for beam scanning described later, the light source 21 does not need to be a coherent laser light source. The light source 21 emits ultraviolet light for performing batch exposure under the control of the control device 100 (FIG. 7) described later.

  The shutter 22 controls on / off of exposure by the batch exposure optical system 12 by controlling the passage or shielding of the ultraviolet light emitted from the light source 21 under the control of the control device 100.

  The polarizing plate 23 converts the ultraviolet light that has passed through the shutter 22 into predetermined polarized light. That is, the polarizing plate 23 polarizes the light so that the spatial light modulator 26 can spatially modulate the ultraviolet light from the light source 21.

  The beam integrator 24 makes the ultraviolet 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 that totally reflects the inside of a columnar rod lens such as a square column is used.

  The mirror 25 reflects the ultraviolet light made uniform 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 ultraviolet light reflected by the mirror 25 is projected on the surface of the ultraviolet curable resin 51 in a predetermined rectangular area unit in a shape corresponding to the cross-sectional shape data. As described above, a part of the ultraviolet light is spatially modulated.

  That is, the spatial light modulator 26 is an image having a shape in a predetermined rectangular area unit according to the cross-sectional shape data to be projected based on the drive signal for controlling each pixel of the liquid crystal panel input from the control device 100. Corresponding to the above, the ultraviolet light passing therethrough is spatially modulated by changing the polarization direction of the transmitted light by changing the arrangement of liquid crystal molecules for each pixel.

  As a result, the irradiation of the ultraviolet light to the predetermined rectangular region on the surface of the ultraviolet curable resin 51 corresponds to the shape of the predetermined rectangular region unit corresponding to the cross-sectional shape data, and the rectangular shape corresponding to one pixel of the liquid crystal panel. Each region (hereinafter referred to as an exposure unit region) is turned on / off, and ultraviolet light is collectively irradiated to an exposure unit region in which irradiation of ultraviolet light in a predetermined rectangular region is turned on. Thereby, the predetermined rectangular area on the surface of the ultraviolet curable resin 51 is irradiated with ultraviolet light having a predetermined rectangular area unit according to the cross-sectional shape data.

  Note that the spatial light modulator 26 is not a transmissive liquid crystal panel, but a DMD or reflective liquid crystal element (DMD) configured by arranging minute reflective mirrors whose inclination angle changes according to an input signal for each pixel. LCOS (Liquid crystal on silicon)) may be used.

  The condensing lens 27 is provided between the spatial light modulator 26 and the polarization beam splitter 14, and images the ultraviolet light spatially modulated by the spatial light modulator 26 on the ultraviolet curable resin 51 together with the objective lens 15. Function as a projection optical system.

  The condensing lens 27 is composed of a lens group for correcting distortion when the ultraviolet light spatially modulated by the spatial light modulator 26 passes through the objective lens 15, and functions as a projection optical system. Can be reduced.

  For example, the condensing lens 27 constitutes each lens group so that the condensing lens 27 and the objective lens 15 are symmetric optical systems, so that the ultraviolet light spatially modulated by the spatial light modulator 26 is obtained. The light is condensed at the front focal position of the objective lens 15 on the reflection / transmission surface 14A of the polarization beam splitter 14, thereby reducing distortion.

  The drive unit 28 rotates the spatial light modulator 26 in a direction perpendicular to the optical axis direction under the control of the control device 100, and two orthogonal sides of the rectangular region of the ultraviolet light imaged on the ultraviolet curable resin 51. And a shift between two orthogonal directions of movement of the stage 53, which will be described later, are corrected.

  In the following, the optical axis direction perpendicular to the liquid surface of the ultraviolet curable resin 51 is defined as the z direction, and the moving directions of the stage 53 perpendicular to the z direction and perpendicular to each other are defined as the x direction and the y direction.

  The drive unit 28 drives the spatial light modulator 26 in the z direction under the control of the control device 100 based on the return light detected by the reflected light monitor unit 41 of the beam scan optical system 13 to be described later, and collective exposure optics. The focus of the ultraviolet light irradiated from the system 12 onto the surface of the ultraviolet curable resin 51 is adjusted.

  The beam scan optical system 13 is an optical system for performing a beam scan exposure by scanning a laser beam within a predetermined rectangular region on the surface of the ultraviolet curable resin 51 of the work unit 16. The light source 31, the collimator lens 32, It comprises an anamorphic lens 33, a beam 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.

  The light source 31 is constituted by, for example, a semiconductor laser that emits laser light having a relatively short wavelength in the blue to ultraviolet range. The light source 31 emits a light beam of laser light for performing beam scanning by the beam scanning optical system 13 under the control of the control device 100. The light source 31 may be a gas laser instead of a 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 has a plurality of lenses, and the beam diameter, which is the diameter of the light beam made into a substantially circular shape by the anamorphic lens 33, is set to the aperture of the objective lens 15, NA (numerical aperture), or the like. The beam diameter is adjusted by converting to a suitable desired beam diameter.

  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 under the control of the control device 100, and controls on / off of the beam scan exposure by the beam scan optical system 13. A shutter 36 is provided to control the on / off of the beam scan exposure by controlling the passage or blocking of the light beam, and to control the direct modulation of the light beam radiation at the light source 31 to perform the beam scan. You may make it control on / off of exposure.

  The galvanometer mirrors 37 and 38 include a reflection unit (not shown) such as a mirror that can rotate in a predetermined direction, and an adjustment unit (not shown) that adjusts the angle in the rotation direction of the reflection unit under the control of the control device 100. ), And the adjustment unit adjusts the angle of the reflection unit so that the light beam reflected by the reflection unit is scanned in the x direction or the y direction within a predetermined rectangular region on the surface of the ultraviolet curable resin 51. .

  Specifically, the galvanometer mirror 37 reflects the light beam transmitted through the shutter 36 toward the galvanometer mirror 38 and scans in the x direction within a predetermined rectangular area on the surface of the ultraviolet curable resin 51. The galvanometer mirror 38 reflects the light beam reflected by the galvanometer mirror 37 toward the polarization beam splitter 14 and scans in the y direction within a predetermined rectangular area on the surface of the ultraviolet curable resin 51.

  In the optical modeling apparatus 11, a polygon mirror or the like may be provided instead of the galvanometer mirrors 37 and 38.

  The relay lenses 39 and 40 are formed of a lens group having one or a plurality of lenses. The relay lens 39 emits a parallel incident light beam in parallel over the scan angle at which the light beam is scanned by the galvanometer mirror 37, and forms an image of the light beam reflected by the galvanometer mirror 37 on the galvanometer mirror 38. The relay lens 40 emits a parallel incident light beam in parallel over the scanning angle at which the light beam is scanned by the galvanometer mirror 38, and reflects the light beam reflected by the galvanometer mirror 38 on the reflection / transmission surface 14 </ b> A of the polarization beam splitter 14. To form an image.

  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, so that the galvanometer mirror 37 and the galvanometer mirror 38 are close to each other. Even when the light beam is not disposed at the position, the light beam can be imaged on the reflection / transmission surface 14 </ b> A of the polarization beam splitter 14.

  The reflected light monitor unit 41 detects return light reflected by the surface of the ultraviolet curable resin 51 using, for example, an astigmatism method or a triangulation method, and inputs the detected light to the control device 100.

  The polarization beam splitter 14 combines the ultraviolet light from the batch 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 arranged such that its reflection / transmission surface 14A coincides with the front focal position of the objective lens 15.

  The objective lens 15 is composed of a lens group having one or a plurality of lenses, and forms an image of the ultraviolet light from the batch exposure optical system 12 on the surface of the ultraviolet curable resin 51 and collects the light beam from the beam scanning optical system 13. Shine.

  Further, the objective lens 15 is configured so that the light beam polarized by the galvanometer mirrors 37 and 38 of the beam scanning optical system 13 is scanned at a constant speed within a predetermined rectangular region on the surface of the ultraviolet curable resin 51, that is, The surface of the ultraviolet curable resin 51 is configured to be scanned at a uniform scanning speed.

  For example, the objective lens 15 has an image height Y proportional to the incident angle θ, and has a relationship (Y = f × θ) such that the product of the focal length f and the incident angle θ becomes the image height Y. A so-called fθ lens is used. In this case, since the scanning speed of the light beam is always constant regardless of the incident position on the objective lens 15, it is possible to prevent a difference between the design shape and the actual shape of the hardened layer due to the variation in the scanning speed. In addition, high-precision modeling can be performed.

  The drive unit 15A drives the objective lens 15 in the z direction under the control of the control device 100 based on the return light detected by the reflected light monitor unit 41 of the beam scan optical system 13, and the UV scan resin from the beam scan optical system 13 The focus of the light beam irradiated on the surface of 51 is adjusted. Specifically, the drive unit 15 </ b> A drives the objective lens 15 in the z direction so that the rear focal position of the objective lens 15 coincides with the surface of the ultraviolet curable resin 51 on the stage 53.

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

  The storage container 52 stores the ultraviolet curable resin 51. The stage 53 is immersed in the ultraviolet curable resin 51 of the storage container 52, and moves in the x direction, the y direction, and the z direction under the control of the drive unit 54.

  The driving unit 54 sequentially moves the stage 53 by a predetermined distance in the x direction under the control of the control device 100, so that a predetermined rectangular region (hereinafter, referred to as a rectangular area exposed by the collective exposure optical system 12 or the beam scanning optical system 13). The exposure small area is scanned in the direction of one side of the small exposure area. When the x direction and the direction of one side of the small exposure area are different, the drive unit 54 moves the stage 53 not only in the x direction but also in the y direction under the control of the control device 100. The small exposure area is scanned in the direction of one side of the small exposure area.

  Thereafter, the drive unit 54 moves the stage 53 by a predetermined distance in the x direction and the y direction under the control of the control device 100, thereby arranging the next in the direction of one side of the small exposure region perpendicular to the scanning direction. The small exposure area is moved to the start position of the scanning line. Then, the drive unit 54 scans the small exposure area again in the direction of one side of the small exposure area under the control of the control device 100.

  By repeating the above process and exposing a work area composed of a small number of exposed small areas arranged in the direction of two orthogonal sides of the small exposed area, one layer of the ultraviolet curable resin 51 is exposed. A region having a shape corresponding to the cross-sectional shape data is exposed, and one hardened layer is formed on the stage 53.

  In this manner, the optical modeling apparatus 11 exposes the work area by laying the exposure small areas like tiles in the directions of two sides orthogonal to each other. Accordingly, here, the stereolithography method of the stereolithography apparatus 11 is referred to as a tiling method in order to distinguish it from a beam scan method or a batch exposure method in which the exposure small area and the work area are the same.

  The size of the small exposure area is determined by the rotation angle of the galvanometer mirrors 37 and 38, the diameter and configuration of the objective lens 15, the size of the spatial light modulator 26, and the like.

  Further, the drive unit 54 moves the stage 53 in the z direction by the thickness of one layer every time exposure corresponding to the cross-sectional shape data for one layer is completed under the control of the control device 100. Thereby, a some hardened layer is laminated | stacked and a solid model is modeled.

  Further, the drive unit 54 drives the housing container 52 in the z direction under the control of the control device 100 based on the return light detected by the reflected light monitor unit 41 of the beam scan optical system 13, and the ultraviolet light is emitted from the collective exposure optical system 12. The focus of the ultraviolet light irradiated on the surface of the curable resin 51 and the focus of the light beam irradiated on the surface of the ultraviolet curable resin 51 from the beam scanning optical system 13 are adjusted.

  Next, with reference to FIG. 2, the optical modeling by the optical modeling apparatus 11 will be described.

  In the example of FIG. 2, as shown in FIG. 2A, the work area 70 is a square having a length of 10 cm in the x direction and the y direction, and the exposure small area 71 has a length in the x direction and the y direction. It shall be a 1cm square. Accordingly, the work area 70 is configured by arranging 10 exposure small areas 71 in the x direction and the y direction, respectively.

  In FIG. 2A, assuming that the central area 73 of the work area 70 is an area having a shape corresponding to the cross-sectional shape data, when the stereolithography apparatus 11 performs exposure using only the batch exposure optical system 12, the work area 70 is FIG. 2B shows an enlarged view of the second small exposure region 71A from the bottom and the third small exposure region 71A from the left among the small exposure regions 71 that constitute the image.

  That is, assuming that the number of pixels in the x direction and y direction of the spatial light modulator 26 is 1000 pixels, as shown in FIG. 2B, there are 1000 exposure unit areas in the x direction and y direction of the small exposure area 71A. Thus, the length of each exposure unit area in the small exposure area 71A in the x and y directions is 10 μm.

  On the other hand, in the conventional batch exposure method, since the exposure small area and the work area are the same, the length of each exposure unit area in the exposure small area in the x direction and the y direction is 100 μm (= 10 cm / 1000). Pieces). Therefore, in the tiling method batch exposure by the stereolithography apparatus 11, the batch exposure can be performed with higher definition than the batch exposure method batch exposure. As a result, the optical modeling apparatus 11 can perform high-definition modeling.

  In FIG. 2B, a hatched area is an exposure unit area that is collectively exposed by the batch exposure optical system 12 in the small exposure area 71A, and a two-dot chain line indicates a contour line corresponding to the cross-sectional shape data. Represents. As shown in FIG. 2B, when exposure is performed using only the collective exposure optical system 12, only the exposure unit area inside the outline is exposed, and the exposure unit area and the outline overlap. The exposure unit area located outside is not exposed.

  On the other hand, when the stereolithography apparatus 11 performs exposure using both the batch exposure optical system 12 and the beam scan optical system 13, when the exposure small area 71A is enlarged, the result is as shown in FIG. 2C.

  In FIG. 2C, the hatched area is the exposure unit area that is collectively exposed by the batch exposure optical system 12 in the small exposure area 71A, and the two-dot chain line indicates the contour line of the shape corresponding to the cross-sectional shape data. Represents.

  As shown in FIG. 2C, when the stereolithography apparatus 11 performs exposure using both the batch exposure optical system 12 and the beam scan optical system 13, the contour is formed by the batch exposure optical system 12 as in the case shown in FIG. 2B. After the exposure unit area inside the line is exposed, as shown in FIG. 2C, the beam scan optical system 13 performs vector scanning or raster scanning, and the exposure is overlapped with contour lines that cannot be collectively exposed. An area inside the outline of the unit area is exposed. A vector scan is a curved scan, and a raster scan is a scan that reciprocates in one direction.

  As described above, when the stereolithography apparatus 11 performs exposure using both the batch exposure optical system 12 and the beam scan optical system 13, the contour line of the exposure unit region where the contour lines that cannot be collectively exposed overlap. Since the inner region can be subjected to beam scan exposure, the shape corresponding to the cross-sectional shape data can be exposed with high definition as compared with the case where exposure is performed using only the batch exposure optical system 12. As a result, a high-definition three-dimensional model can be formed.

  Further, in the stereolithography apparatus 11, since the beam scan exposure is also performed by the tiling method, the beam scan range becomes smaller than the beam scan exposure of the conventional beam scan method in which the exposure small area and the work area are the same, Beam scan exposure can be performed with high definition.

  In FIG. 2, the directions of two orthogonal sides of the square in the small exposure area 71 coincide with the x direction and the y direction, which are the movement directions of the stage 53, but in reality, they often do not coincide.

  In this case, as shown in FIG. 3, the directions of two orthogonal sides of each small exposure area 91 are inclined with respect to the x direction and the y direction, so that the drive unit 54 moves the stage 53 when scanning the small exposure area 91. When moved in the x direction, the scanning direction and the direction of one side of the small exposure area 91 are different, and an overlap 92 occurs in the adjacent small exposure area 91. As a result, there arises a problem that a desired shape cannot be exposed.

  As a method for solving this problem, for example, a method of rotating the spatial light modulator 26 or the stage 53 so that the directions of two orthogonal sides of the small exposure area 91 coincide with the x direction and the y direction can be considered. It is done. However, since it is difficult to slightly rotate the spatial light modulator 26 or the stage 53, it is difficult to make the directions of two orthogonal sides of the small exposure region 91 coincide with the x direction and the y direction in units of microns.

  Therefore, the optical modeling apparatus 11 moves the stage 53 not only in the x direction but also in the y direction when scanning the exposure small area 91 so that the scanning direction and the direction of one side of the exposure small area 91 coincide with each other. The small exposure areas 91 to be overlapped are not overlapped.

  Specifically, the user first moves the stage 53 only in the x direction when scanning the small exposure area 91, for example, exposes the entire two small exposure areas 91, and creates a test three-dimensional model. Model.

  In this case, as shown in FIG. 4, the small exposure area 91 is a square having a length of one side L, and the inclination angles of the two orthogonal directions of the small exposure area 91 with respect to the x direction and the y direction are If θ, an overlap 92 occurs in the adjacent small exposure area 91, so that the cross-sectional shape of the test three-dimensional model is the shape of the area 93.

Next, the user measures the lengths a and b in FIG. 4 of the cross section of the test three-dimensional model and inputs them to the control device 100. Using the input lengths a and b, the control device 100 converts Lsin θ (= Lb / a) into a single x-direction movement amount (hereinafter referred to as x-direction) when scanning the exposure small area 91 in the x-direction. Lcosθ (= L√ (1−b ² / a ² )) is obtained as a movement amount during scanning in the x direction of the exposure small area 91 (hereinafter referred to as the y direction). It is calculated as a movement amount during scanning. That is, the x-direction scanning movement amount and the y-direction scanning movement amount are determined according to the angle θ.

  Then, the control device 100 sequentially controls the stage 53 by Lcosθ in the x direction when scanning the small exposure area 91 by controlling the driving unit 54 based on the movement amount during the x direction scanning and the movement amount during the y direction scanning. In addition to moving, sequentially move in the y direction by Lsinθ. Thereby, the scanning direction and the direction of one side of the small exposure area 91 coincide.

  As a result, as shown in FIG. 5, adjacent small exposure areas 91 do not overlap each other, and a desired shape can be exposed.

  3 to 5, the x direction and the y direction, which are the moving directions of the stage 53, are orthogonal to each other, but in reality, the orthogonality accuracy may be poor.

  In this case, when the angle between the x direction and the y direction is α, when scanning the small exposure area 91, the stage 53 is sequentially moved by Lcosθ in the x direction, and even if the stage 53 is sequentially moved by Lsinθ, the x direction Since only Lsinθ × sinα moves in the direction perpendicular to the scanning direction, the direction of one side of the small exposure area 91 does not match. As a result, an overlap 92 occurs in the adjacent small exposure areas 91, which causes a problem that a desired shape cannot be exposed.

  Therefore, the user moves the stage 53 sequentially by Lcos θ in the x direction and sequentially moves Lsin θ in the y direction when scanning the exposure small region 91, for example, to expose the entire two exposure small regions 91, Re-model the 3D model for testing. The cross-sectional shape of the test three-dimensional model thus formed is the shape of the region 94 in FIG.

  Next, the user measures the length of the cross section of the test three-dimensional model in FIG. 6 and inputs it to the control device 100. The control device 100 obtains sinα (= c / Lsinθ) using the input length c and Lsinθ, which is the movement amount during the y-direction scanning during the test, and further calculates Lsinθ / sinα during the y-direction scanning. Obtained as the amount of movement. Further, the control device 100 does not change the movement amount during x-direction scanning from the movement amount during x-direction scanning during the test, and keeps Lcosθ. That is, the movement amount during x-direction scanning is determined according to the angle θ, and the movement amount during y-direction scanning is determined according to the angles θ and α.

  Then, the control device 100 sequentially controls the stage 53 by Lcosθ in the x direction when scanning the small exposure area 91 by controlling the driving unit 54 based on the movement amount during the x direction scanning and the movement amount during the y direction scanning. In addition to moving, sequentially move in the y direction by Lsinθ / sinα. As a result, when scanning the small exposure area 91, it moves by Lsinθ in the direction perpendicular to the x direction, and the scanning direction and the direction of one side of the small exposure area 91 coincide. As a result, adjacent small exposure areas 91 do not overlap each other and a desired shape can be exposed.

  As described above, the stereolithography apparatus 11 moves the stage 53 not only in the x direction but also in the y direction when scanning the exposure small area 91, so that the directions of two orthogonal sides of the exposure small area 71 are orthogonal. Even if the x direction and the y direction, which are the moving directions of the stage 53, do not coincide with each other, the scanning direction and the direction of one side of the exposure small area 91 can be made coincident to expose a desired shape. To.

  As shown in FIG. 2C, when the stereolithography apparatus 11 performs exposure using both the batch exposure optical system 12 and the beam scan optical system 13, the exposure small area 91 and the beam in the batch exposure optical system 12 are used. It is conceivable that both of the small exposure areas 91 in the scanning optical system 13 exist, and the directions of two orthogonal sides of each small exposure area 91 do not coincide with the x direction and the y direction.

  Therefore, in this case, for example, the user corrects the deviation between the two orthogonal directions of the small exposure region 91 in the collective exposure optical system 12 and the x and y directions by rotating the spatial light modulator 26. The scanning direction and the direction of one side of the small exposure area 91 in the beam scanning optical system 13 are matched using a test three-dimensional model formed after the correction.

  Note that by making the scanning direction coincide with the direction of one side of the small exposure area 91 in the beam scanning optical system 13, the scanning direction is not the x direction. Although a fine shift occurs in the direction of the side, as shown in FIG. 2C, in the exposure small area in the batch exposure optical system 12, only the exposure unit area inside the outline of the shape corresponding to the cross-sectional shape data is exposed. Since the outside is exposed by the beam scanning optical system 13, the fine deviation is absorbed by the exposure by the beam scanning optical system 13.

  FIG. 7 illustrates a hardware configuration example of the control device 100 that controls each unit of the optical modeling device 11 of FIG. 1.

  In the control device 100 of FIG. 7, a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, and a RAM (Random Access Memory) 103 are connected to each other by 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 a non-volatile memory, and a network interface. A communication unit 109 that communicates with the apparatus 11 and a drive 110 that drives a removable medium 111 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory are connected.

  In the storage unit 108, for example, a program for converting 3D shape data of a 3D model created by CAD into STL (Stereo Lithography), which is a format in which the surface of the 3D model is represented by a small triangular surface, A program for creating the cross-sectional shape data of the three-dimensional model from the three-dimensional shape data converted into, and a program for controlling the batch exposure optical system 12 and the beam scanning optical system 13 based on the cross-sectional shape data of the three-dimensional model are stored. .

  In such a control device 100, for example, the CPU 101 loads a 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, and via the communication unit 109, By controlling each part of the optical modeling apparatus 11, the optical modeling apparatus 11 is made to perform optical modeling.

  For example, the CPU 101 of the control device 100 determines the intensity of the ultraviolet light emitted from the light source 21 or the light beam emitted from the light source 31 in accordance with the input from the input unit 106, and outputs a control signal for controlling it. Then, the light is input to the light source 21 or 31 via the communication unit 109. The CPU 101 inputs a control signal for controlling on / off of exposure to the shutter 22 or 36 via the communication unit 109 in response to an input from the input unit 106.

  In addition, the CPU 101 sends a drive signal for controlling each pixel of the liquid crystal panel via the communication unit 109 so that an image of the shape of the small exposure area corresponding to the cross-sectional shape data is displayed according to the cross-sectional shape data. To the spatial light modulator 26. In response to an input from the input unit 106, the CPU 101 inputs a control signal for rotating the spatial light modulator 26 by a desired angle to the drive unit 28 via the communication unit 109.

  Further, the CPU 101 drives a control signal for driving the spatial light modulator 26 in the z direction via the communication unit 109 based on the return light input from the reflected light monitor unit 41 via the communication unit 109. Input to the unit 28, a control signal for driving the objective lens 15 in the z direction to the driving unit 15A via the communication unit 109, or a control signal for driving the container 52 in the z direction. Or input to the drive unit 54.

  Further, the CPU 101 outputs a control signal for adjusting the angle of the reflecting portion of the galvanometer mirrors 37 and 38 so that the shape of the exposure small area unit corresponding to the cross-sectional shape data is exposed according to the cross-sectional shape data. Input to the galvanometer mirrors 37 and 38 via the communication unit 109.

  Further, the CPU 101, based on the lengths a and b or the lengths a to c input from the input unit 106, as described in FIGS. 3 to 6, moves in the x-direction scanning and movement in the y-direction scanning. Find the amount.

  In addition, the CPU 101 sends a control signal for moving the stage 53 in the x direction by the amount of movement during x-direction scanning and to move in the y direction by the amount of movement during y-direction scanning at a predetermined timing via the communication unit 109. Input to the drive unit 54 to scan the small exposure area in the x direction. When the scanning of the small exposure area in the x direction ends, the CPU 101 inputs a control signal for moving the small exposure area to the start position of the next scanning line via the communication unit 109 to the drive unit 54.

  Further, every time exposure corresponding to the cross-sectional shape data for one layer is completed, the CPU 101 sends a control signal for moving the stage 53 by the thickness of one layer in the z direction via the communication unit 109. 54.

  Next, the stage moving process by the CPU 101 in FIG. 7 will be described with reference to the flowchart in FIG. This stage moving process is started, for example, when the user instructs the start of modeling by operating the input unit 106.

  In step S <b> 11, the CPU 101 obtains an x-direction scanning movement amount and a y-direction scanning movement amount based on the lengths a and b or the lengths a to c input by the input unit 106.

  Specifically, when none of the lengths a to c is input from the input unit 106, the CPU 101 sets the movement amount during x-direction scanning as the length L of one side of the small exposure area, and the movement amount during y-direction scanning. Is 0. On the other hand, when the lengths a and b are input from the input unit 106, the CPU 101 obtains Lcos θ as the movement amount during the x-direction scanning based on the lengths a and b as described with reference to FIGS. , Lsinθ is obtained as the movement amount during the y-direction scanning.

  When the lengths a to c are input from the input unit 106, as described with reference to FIG. 6, the CPU 101 obtains Lcosθ as the movement amount during x-direction scanning based on the lengths a to c, and calculates Lsinθ / Find sin α as the amount of movement during scanning in the y direction.

  In step S <b> 12, the CPU 101 inputs a control signal to the driving unit 54, so that the exposure small area is positioned at the scanning start position of the first scanning line (for example, the upper left position in the work area). Move.

  In step S <b> 13, the CPU 101 inputs a control signal to the drive unit 54, thereby moving the stage 53 in the x direction by the movement amount during x-direction scanning, and moves the stage 53 in the y direction by the movement amount during y-direction scanning.

  In step S14, the CPU 101 determines whether the process in step S13 has been repeated a predetermined number of times (for example, the number of small exposure areas arranged in the x direction in the work area). If it is determined in step S14 that the process in step S13 has not been repeated a predetermined number of times, the process returns to step S13, and the processes in steps S13 and S14 are performed until the process in step S13 is repeated a predetermined number of times. Repeated.

  On the other hand, if it is determined in step S14 that the process of step S13 has been repeated a predetermined number of times, that is, if the scanning of the exposure small area is completed, the CPU 101 inputs a control signal to the drive unit 54 in step S15. Thus, the stage 53 is moved so that the small exposure area is positioned at the scanning start position of the next scanning line.

  In step S <b> 16, the CPU 101 determines whether the process of step S <b> 15 has been repeated a predetermined number of times (for example, the number of small exposure areas arranged in the y direction in the work area). If it is determined in step S16 that the process in step S15 has not been repeated a predetermined number of times, the process returns to step S13, and the processes in steps S13 to S16 are performed until the process in step S15 is repeated a predetermined number of times. Repeated.

  On the other hand, if it is determined in step S16 that the process of step S15 has been repeated a predetermined number of times, that is, if a region having a shape corresponding to the cross-sectional shape data for one layer is exposed, in step S17, the CPU 101 By inputting a control signal to the drive unit 54, the stage 53 is moved in the z direction by the thickness of one layer of the three-dimensional model.

  In step S18, the CPU 101 determines whether the process in step S17 has been repeated a predetermined number of times (for example, the number of layers of the three-dimensional model). If it is determined in step S18 that the process in step S17 has not been repeated a predetermined number of times, the process returns to step S12, and the processes in steps S12 to S18 are performed until the process in step S17 is repeated a predetermined number of times. Repeated.

  On the other hand, if it is determined in step S18 that the process of step S17 has been repeated a predetermined number of times, that is, if a three-dimensional model has been formed, the process ends.

  In the above description, the optical modeling apparatus 11 performs optical modeling using the liquid ultraviolet curable resin 51. However, the state of the ultraviolet curable resin is not limited to liquid, and may be, for example, a film. .

  In the above description, the optical modeling apparatus 11 performs optical modeling by the free liquid surface method in which the ultraviolet curable resin 51 is irradiated with light from above the ultraviolet curable resin 51 to cure the ultraviolet curable resin 51 on the liquid surface, but the bottom surface is transparent. Alternatively, the ultraviolet curable resin contained in the container may be irradiated with light from the lower side of the container, and the optical modeling may be performed by a regulated liquid surface method in which the ultraviolet curable resin is cured on the bottom surface of the container. In this case, the surface of the ultraviolet curable resin refers to the interface between the bottom surface of the container and the ultraviolet curable resin.

  Further, in the present specification, the step of describing the program stored in the program recording medium is not limited to the processing performed in chronological order according to the described order, but is not necessarily performed in chronological order. Or the process performed separately is also included.

  The embodiments of the present invention are not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

It is a figure which shows the structural example of one Embodiment of the optical modeling apparatus to which this invention is applied. It is a figure explaining the optical shaping by the optical shaping apparatus of FIG. It is a figure which shows the overlap of a small exposure area | region. It is a figure which shows the overlap of the exposure small area | region in the three-dimensional model for a test. It is a figure explaining the scanning of the exposure small area | region by the optical modeling apparatus of FIG. It is a figure which shows the overlap of the exposure small area | region in the other three-dimensional model for a test. It is a block diagram which shows the hardware structural example of a control apparatus. It is a flowchart explaining the stage movement process by CPU of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 Stereolithography apparatus, 12 Batch exposure optical system, 13 Beam scan optical system, 51 Ultraviolet curable resin, 53 Stage, 54 Drive part,

Claims (3)

In the optical modeling apparatus for modeling the three-dimensional model by irradiating the surface of the photocurable resin with light according to the cross-sectional shape data of the three-dimensional model to form a cured layer and laminating the cured layer,
In accordance with the cross-sectional shape data, exposure means for irradiating light on the surface of the photocurable resin in units of a predetermined rectangular area;
A moving means for moving the rectangular region in at least one of a first direction and a second direction parallel to the surface of the photocurable resin,
The moving means moves the rectangular area by a first distance in the first direction and the second direction in the second direction when the first direction is different from the direction of one side of the rectangular area. An optical modeling apparatus that scans the rectangular area in the direction of the one side by moving the rectangular area by a distance of 2. When the first direction and the second direction are orthogonal to each other, the first distance and the second distance are used for the test formed by irradiating the rectangular area with the light by the exposure unit. The stereolithography apparatus according to claim 1, which is determined according to a direction of one side of the three-dimensional model and an angle of the first direction. When the first direction and the second direction are not orthogonal, the first distance is one side of a three-dimensional model for testing formed by irradiating the rectangular area with the light by the exposure unit. The second distance is determined in accordance with the direction of the first direction and the angle of the first direction, and the second distance is an angle between the direction of the one side and the first direction, and the first direction and the second direction. The stereolithography apparatus according to claim 1, wherein the stereolithography apparatus is determined according to an angle.

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