JP2009113294A - Optical modeling apparatus and optical modeling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To carry out accurate optical modeling by detecting an exact focus state and condensing a light beam for drawing in a proper spot diameter on the cured layer forming surface of a photo-curable resin. <P>SOLUTION: An optical molding apparatus 1 forming a shaped article in a desired shape by forming cured layers in turn by irradiating the liquid photo-curable resin with light is equipped with a light source 11 for drawing which radiates the light beam of a prescribed wavelength for forming the cured layers by drawing the photo-curable resin on a cured layer forming surface, a scanning means 12 for scanning the photo-curable resin by the light beam radiated from the light source 11 for drawing, and a focus detecting light source 31 radiating a light beam of a wavelength which is different from that of the light beam radiated from the light source 11 for drawing and does not cure the photo-curable resin. The cured layer forming surface is irradiated with the light beam radiated from the focus detecting light source 31. By detecting the light beam reflected by the cured layer forming surface, the focus state of the light beam which is scanned by the scanning means 12 is adjusted. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical modeling apparatus and an optical modeling method in which a cured layer is formed by irradiating light to a photocurable resin such as an ultraviolet curable resin, and a resin molded article having a desired shape is formed by laminating the cured layer.

  In recent years, a technique called rapid prototyping (RP) that generates a three-dimensional model, which is a target model, without performing machining or the like using three-dimensional shape data input by a CAD apparatus has been used in many manufacturing sites. It attracts attention.

  Conventionally, rapid prototyping methods include stereolithography using UV curable resins, methods of extruding and laminating thermoplastic resins (FDM), powder melt adhesion laminating method (SLS), and thin film laminating methods. (LOM), a method of discharging and laminating powder and an effective catalyst (Ink-Jet method), and the like are known.

  In the conventional three-dimensional modeling, a modeled object having a desired three-dimensional shape is formed by the following flow. Specifically, first, a target three-dimensional shape (three-dimensional shape data) is input and designed by a computer or the like using a CAD device that is a three-dimensional design system.

  Next, the input CAD data is converted into predetermined three-dimensional shape data such as STL format, and the orientation and stacking direction (upright, inverted, rollover, etc.) of the modeled object are determined, and the thickness in the stacking direction is determined. Is sliced in a circular shape of about 0.1 to 0.2 mm, and cross-sectional data for each layer is generated.

  Based on the cross-sectional data for each layer, a three-dimensional solid model is created by changing the properties of materials such as liquid photocurable resin, powder resin, metal powder, and wax from the bottom layer to each layer. Obtainable.

  Specifically, for example, in the case of a liquid photocurable resin, as shown in FIG. 24, the cured layer is irradiated with the light beam B201 from above on the liquid photocurable resin 202 stored in the resin storage tank 203. As shown in FIG. 25, there is further provided a transparent plate that transmits a resin curing light beam, and the transparent plate vibrates the liquid level of the ultraviolet curable resin. There is a stereolithography method in the form of a so-called liquid level regulation method that suppresses swinging and the like.

  The case where this liquid photocurable resin and the free liquid level method are used will be described with reference to FIG. 24. First, a predetermined thickness that is a first layer on the movable frame 204 moved in a direction perpendicular to the liquid level 202b. Next, after moving the movable base 204 downward, a hardened layer having a predetermined thickness is formed on the first hardened layer, and the lamination is further advanced to form an n-1 layer. A three-dimensional shape model can be obtained by forming an nth cured layer on the cured layer of the eye.

  On the other hand, when the liquid level regulation method is used, as shown in FIG. 25A, a transparent plate 205 is added to the liquid level 202b of the free liquid level method described with reference to FIG. A type that regulates the swinging of the surface and the like and irradiates the light beam B201 from the upper side to form on the upper surface of the movable frame 204, and a bottom surface portion of the resin storage tank 213 as shown in FIG. A bottom transmission part 213a formed of a transparent plate such as glass is provided to regulate the swinging of the liquid photocurable resin between the movable base 214 and the bottom transmission part 213a, and from the lower side through the bottom transparent plate. There is a type that is irradiated and shaped on the lower surface of the movable stand 214. The type that irradiates the light beam from the upper side is the same as the above-described free liquid surface method except that the light beam is irradiated to the photo-curable resin through the transparent plate, and the description is omitted here.

  Then, the case of using the liquid photocurable resin and the liquid level regulation method (type of irradiating the light beam from the lower side) will be described with reference to FIG. 25B. First, the movement is moved in the vertical direction. The ultraviolet curable resin 212 between the lower surface of the base 214 and the bottom transmission part 213a of the resin storage tank 213 is irradiated with light B211 from the bottom transmission part 213a side to form a cured layer having a predetermined thickness as the first layer. Next, after moving the movable base upward, a hardened layer having a predetermined thickness is formed on the first hardened layer, that is, on the lower side, and the lamination is further advanced to the n-1 layer. A three-dimensional shape model can be obtained by forming an nth cured layer on the cured layer of the eye.

  The three-dimensional modeling method as described above and the modeling apparatus that realizes the three-dimensional modeling easily produce a three-dimensional shape having a free-form surface or a complicated structure that has been difficult to cut by a three-dimensional object manufacturing method by machining. It is possible to obtain a desired three-dimensional shape (model) by a fully automated process without generation of tool wear, noise, vibration, cutting waste and the like required for machining.

  In order to apply such a useful three-dimensional modeling technique to various fields such as the production of a high-definition resin molding having an accuracy of about several μm, higher-definition and higher-speed modeling is desired.

  However, since there is no conventional three-dimensional modeling method and three-dimensional modeling apparatus that perform accurate focus detection, there is a limit to increasing the precision of stereolithography. That is, in order to improve the precision of stereolithography, it is necessary to focus the light beam. For this purpose, a mechanism such as autofocus is required.

  Specifically, if the beam spot diameter is up to about 50 μm (micron), it is possible to perform focusing from the relationship between the light beam drawing position calculated in advance and the focus state corresponding to each position. In conventional stereolithography apparatuses, focusing is performed by such a method. However, when higher precision is required and the spot diameter of the light beam needs to be on the order of several microns, it is necessary to perform focusing while examining the focus state of the light beam in real time.

  As a method for performing focus detection in real time in stereolithography, for example, it is conceivable to apply an astigmatism method used in a technique such as an optical disc. That is, a detector or the like that receives and detects the reflected light at the cured layer forming surface of the photocurable resin of the light beam for exposure drawn to cure the photocurable resin at the time of stereolithography, A method of detecting the focus state by receiving reflected light with this detector is conceivable.

  However, in any case of the above-described free liquid level method and liquid level regulation method, when performing modeling, it is necessary to switch on and off the light beam for exposure according to the shape to be modeled. There is a problem that a focus signal cannot be obtained during the off state. Since the off period is limited in the above-mentioned optical disc technology, there is a method to solve this problem. However, when this is applied to the field of stereolithography, how long the off period lasts is expected. There is a risk that it will not be possible and will be a big problem.

  In general, in the case of the liquid level regulation method, which is considered to be superior when high definition is required, for example, as shown in FIG. The first reflected light B221 reflected from the lower surface 213b on the incident side of the bottom transmissive part 213a, the bottom transmissive part 213a, the photocurable resin 212, Two reflected lights reflected at at least two places are generated with the second reflected light B222 reflected from the upper surface 213c of the bottom transmitting portion 213a which is the interface of The first reflected light B221 is generated with a reflectance of several percent unless a non-reflective coating or the like is applied due to a difference in refractive index between the glass and air, for example, but the glass ( The second reflected light B222 from the interface between the bottom transmitting portion 213a) and the photocurable resin 212 is generated with a reflectance that is difficult to detect because, for example, the difference in refractive index between glass and the ultraviolet curable resin is small. It becomes. As described above, in the case of the liquid level regulation method, there is a problem regarding the intensity of the return light when trying to detect the focus by the return light generated simply by reflection with the photo-curable resin. There is a problem that it may not be possible to detect the correct focus state.

  As described above, the real-time focus detection cannot be performed accurately in the optical modeling apparatus, and thereby, the light beam for drawing is focused on the cured layer forming surface of the photocurable resin with an appropriate spot diameter. Therefore, high-precision optical modeling was difficult.

Japanese Patent Laid-Open No. 5-77323

  An object of the present invention is to perform accurate optical modeling by detecting an accurate focus state and condensing a drawing light beam on a cured layer forming surface of a photocurable resin with an appropriate spot diameter. It is in providing the optical modeling apparatus and optical modeling method which can be performed.

  Moreover, the objective of this invention is providing the optical modeling apparatus and optical modeling method which can detect a focus detection signal reliably.

  In order to achieve this object, an optical modeling apparatus according to the present invention is an optical modeling apparatus that forms a molded article of a desired shape by sequentially forming a cured layer by irradiating light to a liquid photocurable resin. A drawing light source that emits a light beam having a predetermined wavelength for forming a cured layer by drawing the photo-curable resin on the cured layer forming surface, and a light beam emitted from the drawing light source A scanning means for scanning the curable resin, a focus detection light source that emits a light beam having a wavelength different from that of the light beam emitted from the drawing light source and a wavelength that does not cure the photocurable resin; A detection means for detecting a light beam emitted from the focus detection light source and irradiated on the cured layer forming surface and reflected by the cured layer forming surface, and the detection result detected by the detecting means Zui by adjusting the focus state of the light beam scanned by said scanning means.

  Moreover, in order to achieve this object, the optical modeling method according to the present invention is an optical modeling method in which a liquid photocurable resin is irradiated with light to sequentially form a cured layer to form a modeled object having a desired shape. A drawing light source that emits a light beam having a predetermined wavelength for forming the cured layer by drawing the photocurable resin on the cured layer forming surface; and a light beam emitted from the drawing light source; And a focus detection light source that emits a light beam having a different wavelength and a wavelength that does not cure the photo-curable resin, and radiates a light beam from each of the focus detection light sources and emits the light beam emitted from the focus detection light source. By irradiating the hardened layer forming surface and detecting the light beam reflected by the hardened layer forming surface, the light beam emitted from the drawing light source is detected by the detecting means and detected by the detecting means. Based on the result of detection is scanned over the hardened layer forming surface while adjusting the focus state of the emitted light beam from the drawing light source by the scanning means for scanning the above photocurable resin.

  The present invention accurately detects a focus by using a light beam for drawing for curing a photocurable resin and a light beam for focus detection for detecting a cured layer forming surface of the photocurable resin. And exposure of the photocurable resin with the light beam for drawing allows the light beam for drawing to be focused on the cured layer forming surface of the photocurable resin with an appropriate spot diameter. Improves accuracy and realizes high-resolution stereolithography.

  Hereinafter, an optical modeling apparatus to which the present invention is applied will be described with reference to the drawings.

  As shown in FIG. 1, the optical modeling apparatus 1 to which the present invention is applied is a light that irradiates light on a photocurable resin to sequentially form and laminate a cured layer to form a modeled object having a desired shape. It is a modeling device. In the following description, it is assumed that a liquid ultraviolet curable resin is used as the photocurable resin. However, the present invention is not limited to this. That is, as long as a cured layer is formed by irradiation with light. Good.

  Specifically, as shown in FIG. 1, the optical modeling apparatus 1 includes a resin storage tank 3 that stores a liquid ultraviolet curable resin 2 as a photocurable resin, and a curing that is formed by being immersed in the resin storage tank 3. The movable frame 4 that holds the layer 2a on the lower surface side and is movable at least in the vertical direction Z perpendicular to the liquid surface that is the surface of the ultraviolet curable resin 2, and irradiates the ultraviolet curable resin 2 with light. And an optical system 5 having a beam scanning optical system 10 and a focus detection optical system 30 to be described later.

  At the bottom of the resin reservoir 3, a transmission part 3a for transmitting the curing light from the optical system 5 is provided, and the optical modeling apparatus 1 transmits the light from the optical system 5 through the transmission part 3a. Then, the cured layer is formed by irradiating the cured layer forming surface, which is a region where the cured layer of the ultraviolet curable resin 2 is formed. In other words, a predetermined gap corresponding to the thickness of each cured layer is formed between the lower surface of the movable frame 4 and the upper surface of the transmission portion 3a, and the ultraviolet curable resin 2 existing in the predetermined gap is It becomes the hardened layer formation surface by which it exposes with the light from the optical system 5 and a hardened layer is formed.

  Then, the optical modeling apparatus 1 sequentially repeats the operation of irradiating light by the optical system 5 to form a hardened layer on the lower surface of the movable mount 4 and the operation of moving the movable mount 4 upward in the vertical direction Z. Perform 3D modeling. In addition, after the above-mentioned hardened layer is formed, a region where a predetermined gap is formed between the hardened layer formed on the lower surface of the movable frame 4 and the upper surface of the transmission part 3a is the hardened layer forming surface. Become.

  The transmission part 3a of the above-described resin storage tank 3 forms a gap as a cured layer forming surface between the lower surface of the movable frame 4 or the cured layer formed on the lower surface of the movable frame 4, and an ultraviolet curable resin therebetween. 2 functions as a liquid level regulating plate that regulates or suppresses so as not to generate vibrations 2 or the like. The optical modeling apparatus 1 having the transmission part 3a as a liquid level regulating plate includes a cured layer formed by regulating vibration, swinging, and the like of the ultraviolet curable resin 2 on the cured layer forming surface, and a finally formed solid. The accuracy of the modeled object is increased, that is, high-precision three-dimensional modeling is possible.

  In the optical modeling apparatus 1, the movable gantry 4 will be described as a configuration that can move only in the vertical direction Z. However, a moving unit such as a moving unit 56 of the optical modeling apparatus 51 described below is additionally provided and moved. It is good also as a structure which changes the relative position in the horizontal surface of the mount frame 4 and the optical system 5, and in that case, an area larger than the area | region which can form a hardening layer in the state which fixed the movable mount frame 4 and the optical system 5 It is possible to form a hardened layer, that is, it is possible to form a large shaped article.

  As shown in FIG. 2, the stereolithography apparatus 1 is used as a beam scanning optical system 10 as a drawing light source (beam scanning light source) that emits a light beam for drawing light on the ultraviolet curable resin 2. 1 light source 11 and scanning means 12 for scanning the light beam radiated from the first light source 11 onto the ultraviolet curable resin 2, and radiated from the first light source 11 for the focus detection optical system 30. A focus detection light source 31 that emits a light beam having a wavelength different from that of the light beam to be cured and a wavelength that does not cure the ultraviolet curable resin 2, and further includes a light beam scanned by the scanning unit 12 and focus detection A wavelength-selective mirror 41 is provided as an optical path synthesizing unit that synthesizes the light beam emitted from the light source 31 and guides it to the cured layer forming surface of the ultraviolet curable resin 2.

  The optical modeling apparatus 1 is configured to use the wavelength selective mirror 41 as an optical path synthesizing unit for guiding light from each optical system to the cured layer forming surface of the ultraviolet curable resin 2. However, a wavelength-selective prism, a polarizing beam splitter, or the like may be used as an optical path synthesizing unit constituting the stereolithography apparatus.

  Further, the optical modeling apparatus 1 converts the divergence angle of the light beam emitted from the first light source 11 in order to form the beam scanning optical system 10 together with the first light source 11 and the scanning unit 12 described above. A collimator lens 13 that is substantially parallel light, an anamorphic lens 14 that shapes a substantially elliptical light beam emitted from the collimator lens 13 into a substantially circular shape, and a light beam that is emitted from the anamorphic lens 14 The beam expander 15 converts the beam diameter into a desired beam diameter suitable for the aperture of the objective lens 42 described later, NA (numerical aperture), etc., and adjusts the beam diameter, and the beam expander 15 emits the beam diameter. By adjusting the divergence angle of the light beam and emitting it as a state of convergent light, parallel light, or divergent light, it is applied onto the ultraviolet curable resin 2 by an objective lens 42 described later. To control the focus adjustment lens 16 that adjusts the focus state of the light beam that is emitted, and the passage and shielding of the light beam that irradiates the ultraviolet curable resin 2, that is, to control drawing on / off by the beam scanning optical system 10. The shutter 17 is provided.

  The first light source 11 as a beam scanning light source used in the beam scanning optical system emits a light beam for forming a cured layer by drawing the ultraviolet curable resin 2 on the cured layer forming surface. For example, a semiconductor laser that emits laser light having an oscillation wavelength of about 375 nm. Here, the wavelength is set to 375 nm, but the wavelength is not limited to this, and is capable of curing the photo-curing resin to be used, for example, a laser beam that emits a laser beam having a relatively short wavelength in the blue to ultraviolet range. If it is. Although a semiconductor laser is used here, the present invention is not limited to this, and a gas laser or the like may be used. Here, since a semiconductor laser is used as the first light source 11, a collimator lens 13 for making a substantially parallel light beam after emitting the laser and an analog for making the elliptical light beam a circular light beam. A morphic lens 14 is provided. In this example, the shutter 17 is provided. However, since a semiconductor laser is used as the first light source 11, the light beam is controlled to be turned on / off by directly modulating it. May be.

  The scanning unit 12 of the stereolithography apparatus 1 deflects the incident light beam from the beam expander 15, for example, in the X direction as a first direction in a plane parallel to the liquid surface that is the surface of the ultraviolet curable resin 2. A first galvanometer mirror 21 to be scanned, and a Y direction as a second direction in a plane substantially perpendicular to the X direction and parallel to the liquid surface of the ultraviolet curable resin 2 by deflecting the light beam from the first galvanometer mirror 21 Are provided between the second galvanometer mirror 22 to be scanned, the wavelength selective mirror 41 and the ultraviolet curable resin 2, and collects the light beam from the second galvanometer mirror 22, and the first and second It comprises an objective lens 42 that scans the light beam deflected by the galvanometer mirrors 21 and 22 onto the ultraviolet curable resin 2 at a constant speed.

  Further, the scanning unit 12 includes a first relay lens 23 provided between the first galvanometer mirror 21 and the second galvanometer mirror 22, and a second galvanometer mirror 22 and the wavelength selective mirror 41. And a second relay lens 24 provided.

  The first and second galvanometer mirrors 21 and 22 have reflection means such as a mirror that can be rotated in a predetermined direction, and adjustment means that adjusts the angle of the reflection means in the rotation direction according to an electric signal. In order to scan the light beam in a predetermined direction, the incident light beam is reflected at a predetermined angle, that is, deflected in a desired direction. The region is also referred to as a region). Thus, the first and second galvanometer mirrors 21 and 22 function as beam deflecting means for deflecting the light beam. Here, the first galvanometer mirror 21 is configured to scan the light beam in the X direction, and the second galvanometer mirror 22 is configured to scan the light beam in the Y direction. However, the present invention is not limited to this. What is necessary is just to comprise so that one and the other of the arbitrary two axes | shafts substantially orthogonal may be scanned in the surface parallel to the liquid level of the ultraviolet curable resin 2, ie, the surface which should be scanned on the movable mount frame 4. Further, the beam deflecting means provided in the scanning means 12 for deflecting the light beam in each of predetermined biaxial directions is not limited to the above-described galvanometer mirror, and a polygon mirror or the like may be used.

  The objective lens 42 that scans the light beams deflected by the first and second galvanometer mirrors 21 and 22 onto the ultraviolet curable resin 2 at a constant speed is composed of a lens group having one or a plurality of lenses. The first galvanometer mirrors 21, 22 scan the X direction and the Y direction, reflect the incident light beam reflected by the wavelength selective mirror 41, and form an image by focusing on the ultraviolet curable resin 2. The light beams deflected by the second galvanometer mirrors 21 and 22 are scanned on the ultraviolet curable resin 2 at a uniform scanning linear velocity.

  Here, as the objective lens 42, as shown in FIG. 3, the image height Y is proportional to the incident angle θ, and the product of the focal length f and the incident angle θ becomes the image height Y (Y = A so-called fθ lens having f × θ) 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.

  That is, the fθ lens as the objective lens 42 is scanned by the first and second galvanometer mirrors 21 and 22, for example, with the rotation speeds of the first and second galvanometer mirrors 21 and 22 being equal. It is possible to make the scanning line velocity within the work area imaged by the objective lens 42 constant, and to prevent the difference between the design shape and the actual hardened layer shape due to the variation in the scanning line velocity. To do. That is, for example, when scanning a light beam imaged on a desired straight line inclined with respect to the XY direction, either the scanning linear velocity component in the X direction or the scanning linear velocity component in the Y direction is selected. The objective lens 42 and the first and second galvanometer mirrors 21 and 22 described above can eliminate the fact that the scanned light beam cannot draw a desired straight line when one or both of them vary. . As described above, the objective lens 42, together with the first and second galvanometer mirrors 21 and 22, enables the scanning line speed on the work area to be scanned at a constant speed, thereby realizing high-definition modeling by fine drawing. .

  Note that the objective lens 42 used here is not limited to the fθ lens, and a lens having a normal condensing function is used, and the drive control unit that controls the first and second galvanometer mirrors 21 and 22 is used. The rotational speed is electrically adjusted and controlled, and the light beams deflected by the first and second galvanometer mirrors 21 and 22 are condensed by the objective lens and scanned at a uniform scanning line speed. Good.

  Here, an operation of scanning the light beam emitted from the first light source 11 by the first and second galvanometer mirrors 21 and 22 and the objective lens 42 will be described with reference to FIG. In FIG. 4, the second galvanometer mirror 22, the first and second relay lenses 23 and 24, and the wavelength selective mirror 41 are shown in order to show the operation of the first galvanometer mirror 21 and the objective lens 42. Omitted. Further, the operations of the second galvanometer mirror 22 and the objective lens 42 are the same, and the details are omitted.

  The first galvanometer mirror 21 receives a light beam that has been collimated by the collimator lens 13 and made uniform by the beam expander 15, is scanned in the X direction according to the angle, and is moved by the objective lens 42. Focused on the area.

  As described above, the objective lens 42 allows the light beam scanned in the X direction by the first galvanometer mirror 21 to be incident in a predetermined state, thereby scanning the work area in the X direction and the UV curable resin in the work area. 2 is incident in a vertical direction to form a telecentric image. Similarly, the objective lens 42 allows the light beam scanned in the Y direction by the second galvanometer mirror 22 to enter in a predetermined state, thereby scanning the work area in the Y direction and curing the work area with ultraviolet rays. The light is incident on the resin 2 in the vertical direction to form a telecentric image.

  Incidentally, there is a certain relationship between the scan angle in the scanning direction by the first and second galvanometer mirrors 21 and 22 and the focal length of the objective lens 42. As described above, when the objective lens 42 is an fθ lens, for example, the dimensions of the work area in the X direction and the Y direction are each 1 cm, that is, the work area is about 1 cm × 1 cm, and the first and second galvanometers are used. When the scanning angle of the mirrors 21 and 22 is about ± 10 degrees, the focal length is about 28.65 mm. It is possible to change the size of the work area by changing the scan angle of the first and second galvanometer mirrors 21 and 22 and the configuration of the objective lens 42.

  Thus, the size of the work area is determined by the rotation angle of the first and second galvanometer mirrors 21 and 22, the diameter and configuration of the objective lens 42, the configuration and arrangement of other optical components, and the like. The work area is an area where a hardened layer can be formed in a state in which the positional relationship in the plane parallel to the liquid surface of the optical system 5 and the movable frame 4, that is, in the horizontal plane does not change, and In the vertical direction Z, it is a region on the hardened layer already formed on the movable frame 4 or the movable frame 4. In other words, the work area means an area where a hardened layer is to be formed.

  In the objective lens 42, the object-side focal position that is the front focal position is matched with the reflection / transmission surface 41 a of the wavelength selective mirror 41, and the image-side focal position that is the rear focal position is the work area on the movable frame 4. The ultraviolet curable resin 2 is arranged in conformity with the ultraviolet curable resin 2. Here, the ultraviolet curable resin 2 in the work area refers to the ultraviolet curable resin 2 in a position where a light beam on the movable frame 4 can be scanned and at which a cured layer of the ultraviolet curable resin 2 is to be formed. In many cases, it means the surface, that is, the position near the liquid surface. Here, the object side focal position of the objective lens is arranged so as to coincide with the reflection / transmission surface 41a. However, it is not necessary to exactly coincide, and the wavelength-selective mirror 41 itself does not become too large. In addition, it is only necessary that the object-side focal position be positioned in the vicinity of the reflection / transmission surface 41a. That is, since it is necessary for all the light beams from the beam scanning optical system 10 to pass (reflect) through the reflection / transmission surface 41a, there is no object in the vicinity of the reflection / transmission surface 41a so that the wavelength selective mirror 41 does not become too large. The object-side focal position of the lens 42 may be positioned.

  The first and second relay lenses 23 and 24 can emit parallel incident light beams in parallel over the necessary scan angles by the first and second galvanometer mirrors 21 and 22, and can also be used as first object surfaces. The light beam reflected on the first or second galvanometer mirror 21 or 22 can be imaged on the next galvanometer mirror 22 or the reflection / transmission surface 41 a of the wavelength selective mirror 41.

  That is, the first relay lens 23 includes a lens group having one or a plurality of lenses, and images the light beam reflected by the first galvanometer mirror 21 on the reflection surface on the second galvanometer mirror 22. The second relay lens 24 includes a lens group having one or a plurality of lenses, and forms an image of the light beam reflected by the second galvanometer mirror 22 on the reflection / transmission surface 41 a of the wavelength selective mirror 41.

  The first and second relay lenses 23 and 24 having such a function are configured to be both-side telecentric imaging optical systems. FIG. 5 shows an optical system that is a representative example of an optical system that is a double-sided telecentric imaging optical system, and is also called a “4f optical system”. In the telecentric imaging optical system as shown in FIG. 5, for example, the object plane Po corresponding to the first and second galvanometer mirrors 21 and 22 is arranged at the front focal position of the lens arranged at the most forward position. The image plane Pi corresponding to the second galvanometer mirror 22 or the wavelength-selective mirror 41 is arranged at the rear focal position of the lens arranged at the most rear side position, so that it can be placed at any position on the object plane Po. When the condensed light beam diverges and enters, it is converged to a corresponding position on the image plane Pi side. Then, a light beam incident as parallel light from an arbitrary position on the object plane Po enters the corresponding position on the image plane Pi side as parallel light. In this way, the double-sided telecentric imaging optical system emits parallel light incident in a predetermined position and a predetermined direction from the image plane side to a corresponding position on the image plane side in a corresponding direction. Become.

  The second relay lens 24 guides the light beam deflected by the second galvanometer mirror 22 so that it passes through the object side focal position of the objective lens 42, that is, passes through the center of the reflection / transmission surface 41a. The object side focal position can be passed through at a predetermined angle so as to enter the predetermined position of the objective lens 42. That is, in the second relay lens 24, the optical axis of the light beam deflected by the second galvanometer mirror 22 passes through the front focal point of the objective lens 42 at an angle corresponding to the position scanned in the work area. It can be guided to enter the objective lens 42.

  The first relay lens 23 is deflected by the first galvanometer mirror 21, and the light beam after passing through the second galvanometer mirror 22 and the second relay lens 24 passes through the object side focal position of the objective lens 42. In other words, the object can be guided so as to pass through the center of the reflection / transmission surface 41a and pass through the object-side focal position at a predetermined angle so as to enter the predetermined position of the objective lens. That is, in the first relay lens 23, the optical axis of the light beam deflected by the first galvanometer mirror 21 passes through the front focal point of the objective lens 42 at an angle corresponding to the position scanned in the work area. It can be guided to enter the objective lens 42.

  In other words, the first and second relay lenses 23 and 24 once convert the light beams deflected and scanned in the X direction and the Y direction by the first and second galvanometer mirrors 21 and 22 arranged at different positions, once into the objective lens. 42 front focal positions can be passed.

  The first and second relay lenses 23 and 24 are arranged in the X and Y directions of the light beams that are deflected and scanned in the X and Y directions by the first and second galvanometer mirrors 21 and 22 arranged at different positions. Since the passing position in the direction is adjusted so as to pass once through the front focal position of the objective lens 42 such as the fθ lens, the object side focal point of the fθ lens is scanned with the light beam modulated in two dimensions. The light beam that is collected by the objective lens 42 is projected with respect to the liquid surface of the ultraviolet curable resin 2 regardless of the scanning position. This makes it possible to achieve high-definition modeling by preventing the inclined surface from being formed in each hardened layer by converging the light beam obliquely.

  Further, since the first and second relay lenses 23 and 24 need to synthesize an optical path with a focus detection optical system 30 to be described later, a wavelength selective mirror 41 is disposed, and an ultraviolet ray is emitted from the wavelength selective mirror 41. The first and second galvanometer mirrors 21 and 22 need to be disposed on the first light source 11 side of the wavelength selective mirror 41 and the objective lens 42 needs to be disposed on the cured resin 2 side. The galvanometer mirrors 21 and 22 and the wavelength selective mirror 41 can be prevented from physically colliding with each other due to the rotation of the reflecting means of the galvanometer mirror, that is, the distance is separated from the colliding range. Make it possible.

  Here, the wavelength selective mirror 41 is disposed in order to make the optical paths of the beam scanning optical system 10 and a focus detection optical system 30 to be described later coincide. As a result, the workpiece region is irradiated with a light beam from the vertical direction in the beam scanning optical system 10 and is irradiated from an oblique direction inclined from the vertical direction, whereby an inclined surface is formed in each cured layer. This is for realizing high-definition modeling. Also, the focus detection optical system 30 can perform accurate focus detection by irradiating a focus detection light beam from a predetermined position and direction.

  Further, the objective lens 42 needs to be arranged on the ultraviolet curable resin 2 side from the wavelength selective mirror 41. If the objective lens 42 is arranged in front of the wavelength selective mirror 41, the wavelength selective mirror 41 This is because the distance between the objective lens 42 and the ultraviolet curable resin 2 is increased by disposing the objective lens 42 closer to the ultraviolet curable resin 2 than the wavelength selective mirror 41. This is because it is possible to prevent the occurrence of problems such as errors in the light beam irradiation position.

  As described above, the first light source 11, the first and second galvanometer mirrors 21 and 22, the first and second relay lenses 23 and 24, the scanning unit 12 including the objective lens 42, the collimator lens 13, and the like. The anamorphic lens 14, the beam expander 15, the focus adjustment lens 16, and the shutter 17 constitute a beam scanning optical system 10. The beam scanning optical system 10 of the stereolithography apparatus 1 includes the first The light beam emitted from the light source 11 is made substantially parallel by the collimator lens 13, shaped by the anamorphic lens 14, the beam diameter is adjusted by the beam expander 15, and the focus state is adjusted by the focus adjustment lens 16, The first and second relay lenses 23 and 24 pass the first focal position of the objective lens 42 in the first and second relay lenses 23 and 24. The beam is deflected so as to be scanned in the X and Y directions by the second galvanometer mirrors 21 and 22, guided to the objective lens 42 side by the wavelength selective mirror 41, and desired on the ultraviolet curable resin 2 by the objective lens 42. And is condensed to irradiate and draw a fine region to form a hardened layer.

  At this time, in many conventional beam scanning type optical modeling apparatuses, the galvanometer mirror in the X direction and the galvanometer mirror in the Y direction are arranged close to each other to perform two-dimensional scanning. Since the apparatus 1 needs to be combined with a focus detection optical system 30 to be described later, the light beam deflected by the first galvanometer mirror 21 in the X direction by the first relay lens 23 is placed on the second galvanometer mirror 22. An image is formed, and a light beam deflected by the second galvanometer mirror 22 in the Y direction is imaged on the object side focal point of the objective lens 42 by the second relay lens 24.

  In other words, the objective lens 42 needs to be provided with a wavelength selective mirror 41 for combining with the focus detection optical system 30 described later between the first and second galvanometer mirrors 21 and 22 and the work position. The first and second relay lenses 23 and 24 are provided between the first and second galvanometer mirrors 21 and 22 and the work position. Even when the distance is long, a light beam can be imaged with high accuracy at a predetermined position on the first and second galvanometer mirrors 21 and 22 and the work area, and telecentric imaging can be performed. Here, the workpiece position refers to a workpiece region, that is, a position where the ultraviolet curable resin 2 is provided on the movable frame 4.

  As described above, the optical modeling apparatus 1 enables desired fine drawing on the ultraviolet curable resin 2 by the beam scanning optical system 10 including the scanning unit 12 and the like as described above, and thereby the desired precision can be obtained with high accuracy. A hardened layer having a shape can be obtained, thus realizing high-definition modeling.

  The beam scanning optical system 10 includes a raster scan that reciprocates the cross-sectional shape in a predetermined direction and scans linearly according to desired cross-sectional shape data, as shown in FIG. As shown in Fig. 6 (b), the vector scan that smoothly scans the boundary portion (edge portion) etc. in a curved line is appropriately switched, and the raster / vector combination scan is performed in combination as shown in Fig. 6 (c). Is possible.

  Further, the optical modeling apparatus 1, together with the above-described focus detection light source 31, constitutes a focus detection optical system 30, so that a light beam (hereinafter referred to as “reflection”) is irradiated and reflected on the cured layer forming surface of the ultraviolet curable resin 2. A position sensing device (hereinafter also referred to as “PSD”) 32 is provided as reflected light detecting means for detecting light.

  The focus detection light source 31 emits a light beam having a wavelength different from that of the light beam emitted from the first light source 11 for drawing and a wavelength that does not cure the ultraviolet curable resin 2. For example, the focus detection light source 31 is a semiconductor laser that emits laser light having an oscillation wavelength of about 655 nm, for example. Here, the wavelength is set to 655 nm, but the wavelength is not limited to this. Even if the photocurable resin to be used is irradiated, it is not cured, and at the interface between the transmitting portion 3a and the ultraviolet curable resin 2 described later. Any laser beam may be used as long as the laser beam can be emitted to such an extent that a predetermined reflectance can be obtained. Further, since a light beam having a wavelength that does not cure the ultraviolet curable resin 2 is emitted from the focus detection light source 31 as a focus detection light beam, the total amount of light is not reflected at the above-described interface. Even if a part of the light beam for focus detection is irradiated into the ultraviolet curable resin 2, an unnecessary cured layer can be prevented from being formed.

  By the way, as described above, the resin storage tank 3 is formed of, for example, quartz glass having a thickness of about 1.2 mm, so that the portion corresponding to the work area at the bottom functions as the transmission part 3a. The light beam emitted from the first light source 11 for drawing is transmitted to enable the formation of a hardened layer by the beam scanning optical system 10 described above, and functions as a liquid level regulating plate as described above. That is, the swinging of the cured layer forming surface of the ultraviolet curable resin 2 between the movable base 4 and the like is restricted.

  Here, the entire resin storage tank 3 is formed of quartz glass. However, the present invention is not limited to this. For example, the entire bottom surface or at least the portion corresponding to the work area of the bottom is quartz. It should just be formed with the material which has a certain amount of intensity | strength, such as glass and glass, and has a high transmittance | permeability with respect to the light beam for drawing (for exposure). Further, the thickness of the bottom of the resin reservoir 3 is not limited to the above-described 1.2 mm, but has sufficient strength to store the ultraviolet curable resin 2 and is sufficiently transmitted to the drawing light beam. It is necessary to set the rate to have a rate.

  Further, as shown in FIG. 7, the transmitting portion 3 a serving as the liquid level regulating plate is radiated and guided from the first light source 11 serving as the drawing light source to the ultraviolet curable resin 2 side, that is, the upper surface side. A reflective coating film 7 that transmits most of the light beam and reflects most of the light beam emitted from the focus detection light source 31 is formed.

For example, as shown in FIG. 8, the reflective coating film 7 is formed of a layer 7a made of MgF ₂ (magnesium fluoride) with a thickness t1 = about 125 nm and ZrO ₂ (zirconium oxide) on the quartz glass substrate 3b. The layer 7b having a thickness t2 of about 90 nm is formed by alternately laminating. Here, the reflective coating film 7 is configured to be formed by a laminated structure in which two types of layers made of MgF ₂ and ZrO ₂ are alternately laminated. However, the present invention is not limited to this. For example, A plurality of types of layers such as a dielectric multilayer coating may be laminated and formed, or a single layer structure may be formed. May be used as long as the light is substantially transmitted and at least part of the light beam for focus detection is reflected. It should be noted that if the reflectance of the light beam for focus detection by the reflective coating film 7 is about 0.5% or more, focus detection is possible. However, as described here, most of the reflection is reflected. As a result, it is not necessary to provide the light intensity of the focus detection light beam more than necessary, and it is possible to detect the light beam reliably and accurately.

Here, with respect to the configuration of the reflective coating film 7, specific numerical values are given, and the transmittance with respect to the drawing light beam and the focus detection light beam when the reflective coating film 7 thus configured is applied. This will be described with reference to FIG. Here, a reflective coating film 7 consisting of 10 layers in which five layers of 125 nm of MgF ₂ and 90 nm of ZrO ₂ are alternately stacked is formed on the quartz glass substrate 3 b. It will be explained as a thing. Here, the refractive index of the quartz glass substrate @ 550 nm (representing the refractive index with respect to the light beam having a wavelength of 550 nm) is set to 1.462, the refractive index of Mgf ₂ @ 550 nm is set to 1.379, and ZrO ₂ FIG. 9 shows a change in reflectance with respect to a change in wavelength when the refractive index of 550 nm is 2.1 and the refractive index of the UV curable resin 2 is 550 nm. In FIG. 9, the horizontal axis indicates the wavelength of the light beam (WAVELENGTH IN μm), the vertical axis indicates the reflected light intensity (INTENSITY REFLECTION), and the curve indicates the reflection according to the change in the wavelength of the incident light beam. It shows a change in light intensity. As shown in FIG. 9, the reflective coating film 7 thus formed on the quartz glass has an interface with the ultraviolet curable resin 2 and a reflectance of a light beam having a wavelength of 375 nm (light beam for drawing) is 0. It can be confirmed that the transmittance sufficient for exposure is obtained, and the reflectance of the light beam with a wavelength of 655 nm (light beam for focus detection) is 95%, and sufficient reflectance for focus detection is obtained. Can be confirmed.

  Thus, the transmission part 3a as a liquid level regulating plate transmits the light beam for drawing and guides it to the cured layer forming surface of the ultraviolet curable resin, and the reflective coating film 7 as described above on the ultraviolet curable resin 2 side. The light beam for focus detection can be reflected at the interface between the transmission part 3a and the ultraviolet curable resin 2, and the position of the cured layer forming surface of the ultraviolet curable resin 2 can be accurately determined as described below. It is possible to detect the focus state.

  That is, when the reflective coating film 7 is not provided in the transmission part 3 a provided at the bottom of the resin reservoir 3, the reflected light from the interface between the transmission part 3 a of the focus detection light beam and the ultraviolet curable resin 2. However, since the difference in refractive index between the transmission part 3a and the ultraviolet curable resin 2 is small, the reflection coating film need not be provided if the reflected light can be detected by the reflected light detection means. Further, when the reflective coating film 7 is not provided, focus is achieved by monitoring the reflected light from the interface with the air, which is the lower surface of the transmissive portion 3a, by forming the transmissive portion 3a with a sufficiently uniform thickness. It is also possible to perform detection. On the other hand, the transmissive part 3a having the reflective coating film 7 as described above can reliably reflect the focus detection light beam at a predetermined intensity at the interface with the ultraviolet curable resin 2, and the transmissive part. A more reliable and accurate focus detection is possible regardless of the thickness error of 3a.

  In addition, the transmission part 3a of the resin storage tank 3 demonstrated here is not restricted to what was mentioned above, For example, as shown in FIG. 10, it should provide the peeling coating film 7C further on the upper surface of the reflective coating film 7 Alternatively, the anti-reflection coating film 7D may be provided on the lower surface side that is the incident side of the light beam. The release coating film 7 </ b> C provided here is, for example, a fluorine coating. When the release coating film 7 </ b> C is provided, when the formation of an arbitrary hardened layer is completed, the release coating film 7 </ b> C is formed from the transmission part 3 a that is the bottom thereof. The cured layer can be easily peeled off. Further, the anti-reflection coating film 7D can prevent reflection on the lower surface, which is a surface on the incident side, of the light transmitting portion 3a for drawing and / or focus detection. By providing, the light use efficiency of the light beam for drawing can be increased, and / or the reflected light from the interface between the transmitting portion 3a and the air is reflected on the reflected light from the interface between the transmitting portion 3a and the ultraviolet curable resin 2. It is possible to perform accurate focus detection by preventing mixing. In FIG. 10, the example in which the release coating film 7 </ b> C and the antireflection coating film 7 </ b> D are provided at the same time has been described. However, either one may be provided.

  The PSD 32 as reflected light detection means of the focus detection optical system 30 receives and detects the reflected light that is reflected at the interface between the transmission part 3 a and the ultraviolet curable resin 2 and passes through the wavelength selective mirror 41. The optical modeling apparatus 1 receives the reflected light emitted from the focus detection light source 31 and reflected at the interface with the ultraviolet curable resin 2 by the PSD 32 to detect the focus state, and the focus adjustment lens 16 performs the focus state. The focus correction can be performed by adjusting.

  Specifically, the focus detection optical system 30 including the focus detection light source 31 and the PSD 32 detects a focus correction signal by trigonometry. That is, as shown in FIG. 11 (a), the height of the cured layer forming surface of the ultraviolet curable resin 2, that is, the cured layer forming surface when the focus state is aligned with the interface between the ultraviolet curable resin 2 and the transmitting portion 3a. If the position is L0 and the position of the reflected light from this interface on the light receiving surface of the PSD 32 on the light receiving surface in this case is P0, as shown in FIG. On the other hand, when the height L1 of the hardened layer forming surface is deviated, that is, when the focus state is deviated from the in-focus position, the position P1 of the reflected light from the interface on the light receiving surface of the PSD 32 is aligned. It is detected at a position shifted with respect to the light receiving position P0 in the focused state corresponding to the shift amount from the focused position. FIG. 11 (b) shows the detection position of the return light when reflected at the back position with respect to the just focus state, and reflected at the near side position with respect to the just focus state. Although illustration of the case is omitted, in that case, return light is detected at a position opposite to the position P1 with respect to the position P0. The PSD 32 can detect the focus state according to the detection position of the reflected light as described above. As described above, the focus detection optical system 30 accurately detects the position of the reflected light incident on the PSD 32, thereby accurately detecting the interface between the transmission part 3a and the ultraviolet curable resin 2, that is, the position in the vertical direction of the cured layer forming surface. can do.

  Here, the focus detection is performed using the trigonometric method, but the focus detection may be performed using the astigmatism method or the like. When the astigmatism method is used, an element for providing astigmatism such as a cylindrical lens may be provided, and the generated astigmatism may be detected to detect a focus correction signal.

  As described above, the optical modeling apparatus 1 includes a focus detection light source 31 that emits a light beam having a wavelength different from that of the drawing light beam as the focus detection optical system 30 and that does not cure the ultraviolet curable resin 2; The reflective coating film 7 is formed on the surface of the transmissive part 3a functioning as a liquid level regulating plate on the ultraviolet curable resin side, and the position of the cured layer forming surface is accurately and accurately provided. For example, when the thickness of the transmission part 3a that is the bottom of the resin storage tank 3 is not uniform, or the amount of the ultraviolet curable resin 2 stored in the resin storage tank 3, the transmission part can be detected. Even when the 3a is bent or when the vertical position of the transmitting portion 3a in the horizontal plane is different due to this bending, the position of the hardened layer forming surface is detected by accurately and reliably detecting the position of the interface. It makes it possible to.

  Here, based on the focus detection signal obtained by the focus detection optical system 30, the focus adjustment by the focus adjustment lens 16 of the beam scan optical system 10 will be described in detail.

  The focus adjustment lens 16 provided in the beam scanning optical system 10 includes, for example, a so-called Galileo type beam expander. Specifically, the first adjustment lens 16a is disposed and fixed on the incident side, and is disposed on the emission side. And a second lens 16b provided to be movable in the optical axis direction. The focus adjustment lens 16 is provided with a focus adjustment drive unit 25 that moves the second lens 16b based on the detected focus state.

  The focus adjustment lens 16 adjusts the focus state by being driven by the focus adjustment drive unit 25 based on a focus correction signal generated by the control unit 101 described later based on the focus detection signal obtained by the PSD 32.

  That is, the focus adjustment lens 16 once converges the incident light beam B0 incident on the first lens 16a by the first lens 16a and then passes through the second lens 16b, as shown in FIG. By moving the second lens 16b away from the first lens 16a, as shown in FIG. 12 (a), by the focus adjustment drive unit 25 from the state of emitting in the state of the parallel light B1. The light beam emitted from the focus adjustment lens 16 can be brought into the state of convergent light B2. Further, the focus adjustment lens 16 is moved from the state shown in FIG. 12B by moving the second lens 16b closer to the first lens 16a as shown in FIG. 12C. The light beam emitted from the focus adjustment lens 16 can be in the state of diverging light B3.

  Then, the focus adjustment lens 16 can bring the focusing position (focus) closer to the objective lens 42 by making the convergent light incident on the objective lens 42 as compared with the state in which the parallel light is incident. By making divergent light incident, the focus position can be separated from the objective lens 42 as compared with a state in which parallel light is incident. As described above, the focus adjustment lens 16 adjusts the light beam passing therethrough to converged light, parallel light, and divergent light at a predetermined angle, thereby focusing the light beam focused on the ultraviolet curable resin 2 by the objective lens 42. Can be adjusted.

  As described above, the optical modeling apparatus 1 accurately detects the position of the hardened layer forming surface by the focus detection optical system 30 and focuses by the focus adjustment lens 16 of the beam scan optical system 10 based on the obtained detection signal. By performing the adjustment, the light beam for drawing can be condensed on the cured layer forming surface of the ultraviolet curable resin 2 with an appropriate spot diameter, and high-precision optical modeling can be performed.

  Moreover, since the optical modeling apparatus 1 can detect an accurate focus state in real time by the focus detection optical system 30, it can be configured to change the spot diameter according to the shape of the hardened layer to be formed. To do. In other words, the optical modeling apparatus 1 performs fine modeling by drawing with a reduced spot diameter for a portion that requires fine exposure, such as a contour portion of a target modeling object, by the control unit 101 described later. Thus, the exposure of the central part of the target modeled object may be configured to perform high-speed modeling by drawing with a large spot diameter, thereby enabling high-speed and high-definition optical modeling. Make it possible.

  Note that the focus detection by the PSD 32 as the reflected light detection means and the focus correction by the focus adjustment lens 16 may be performed at all times, and at least every time each cured layer is formed, that is, the movable gantry 4 is provided. You may comprise so that it may carry out whenever it moves to the perpendicular direction Z.

  By the way, the stereolithography apparatus 1 to which the present invention is applied includes a control device 100 having a hard disk in which a database, a program, and the like are stored, a RAM (Random Access Memory) in which data is loaded, a CPU (Central Processing Unit) that performs calculation, and the like. It has.

  As shown in FIG. 13, the control device 100 includes a control unit 101 that controls various data processing, optical components, and the like, and an input unit 102 that inputs three-dimensional shape data and the like to the control unit 101. And an operation unit 103 for operating the control unit 101.

  As shown in FIG. 13, the control unit 101 performs laser control on the first light source 11, controls light beam transmission and shielding on the shutter 17, and performs first and second galvanometer mirrors 21. , 22 to control the rotational drive of the reflecting means, the fine drawing of the beam scanning optical system 10 is controlled.

  Further, when the stacking of the hardened layers having a predetermined height is completed, the control unit 101 controls the moving gantry 4 to raise the moving gantry 4 in the vertical direction Z by a predetermined amount so that the position of the work area in the Z direction is increased. Change and change the formation layer.

  Further, the control unit 101 receives the focus detection signal detected by the PSD 32, generates a focus correction signal for correcting the shift amount when the focus detection signal is shifted from the just focus state based on the focus detection signal, and By outputting to the adjustment drive unit 25, the focus adjustment lens 16 can be moved in the optical axis direction to perform focus correction and the focus state can be adjusted, thereby realizing further high-definition modeling.

  The stereolithography apparatus 1 to which the present invention is applied is a first light source as a drawing light source that emits a light beam having a predetermined wavelength for forming a cured layer by drawing the ultraviolet curable resin 2 on the cured layer forming surface. 11, scanning means 12 for scanning the ultraviolet curable resin 2 with the light beam emitted from the first light source 11, and the ultraviolet curable resin 2 at a wavelength different from that of the light beam emitted from the first light source 11. A focus detection light source 31 that emits a light beam having a wavelength that does not cure, and irradiates the cured layer forming surface with the light beam emitted from the focus detection light source 31 and reflects the light beam reflected by the cured layer formation surface. By adjusting the focus state of the light beam scanned by the scanning means 12 with the light detected by the reflected light detecting means such as PSD 32, the light beam for drawing is hardened by the ultraviolet curable resin 2. In a suitable spot diameter on the layer-forming surface can be condensed, it realizes to make a high-definition optical shaping to improve the molding accuracy. That is, the stereolithography apparatus 1 to which the present invention is applied accurately detects a focus using a light beam for focus detection, and uses a light curable resin with an appropriate spot diameter by a drawing light beam according to the detection result. High-definition 3D modeling is realized by performing this exposure.

  Further, the optical modeling apparatus 1 to which the present invention is applied enables focus detection in real time by performing focus detection using a light beam for focus detection different from the light beam for drawing, that is, modeling is performed. The focus detection can always be performed even when the exposure light beam is turned off according to the shape of the image, that is, when the exposure layer is not irradiated with the exposure light beam. Realize 3D modeling.

  Further, the stereolithography apparatus 1 to which the present invention is applied transmits light as a liquid level regulating plate that suppresses the swing of the ultraviolet curable resin on the cured layer forming surface and transmits the light beam emitted from the first light source 11. The optical modeling apparatus using the so-called liquid level regulation method having the part 3a, and the optical modeling apparatus using the so-called free liquid level method in which the liquid level of the ultraviolet curable resin is exposed in the air, the accuracy of the cured layer during modeling is liquid By placing a liquid level regulating plate on the resin hardened layer forming surface instead of exposing the resin liquid level in the air, compared to the limit to high accuracy because it is determined by the surface accuracy of the surface By improving the smoothness of the liquid level, the accuracy of the cured layer is improved, that is, high-definition three-dimensional modeling is realized. Furthermore, the optical modeling apparatus 1 to which the present invention is applied uses the above-described liquid level regulation method, and the light beam emitted from the first light source 11 and the focus detection light source 31 is applied to the ultraviolet curable resin. On the other hand, it is guided from the transmission part 3a side as a liquid level regulating plate, and the drawing light beam is transmitted to the upper surface side which is the ultraviolet curable resin 2 side of the transmission part 3a, and the focus detection light beam is reflected. Since the reflective coating film 7 is formed, the liquid level regulating plate is more than the reflected light from the interface (upper surface) with the ultraviolet curable resin 2 of the liquid level regulating plate, which may be a problem when the liquid level regulating method is used. The problem that accurate focus detection cannot be performed due to large reflected light from the air-side surface (lower surface) that is the light incident side of the light is eliminated, that is, the interface with the ultraviolet curable resin 2, that is, a cured layer is formed accurately. surface Position by detecting, implementing detecting a correct focus state.

Furthermore, the stereolithography apparatus 1 to which the present invention is applied is such that the reflective coating film 7 is formed by a laminated film formed by alternately laminating layers made of MgF ₂ and layers made of ZrO _2. For example, for a focusing light beam with a wavelength of about 655 nm, a high reflectivity of about 95% is obtained to achieve good focus detection. For example, for a drawing light beam with a wavelength of about 375 nm, The UV curable resin 2 on the cured layer forming surface is exposed with a high transmittance while keeping the reflectance as low as about 0.5%, thereby improving the light utilization efficiency, increasing the modeling speed and saving power, and high definition. Realize 3D modeling.

  The optical modeling apparatus 1 includes a beam scanning optical system 10 that scans a light beam onto the ultraviolet curable resin 2 to form a cured layer, and detects a focus state on the cured layer forming surface of the ultraviolet curable resin 2. However, the optical modeling apparatus to which the present invention is applied is not limited to this, for example, it has a focus detection optical system, In addition to the above-described beam scanning optical system for performing high-definition optical shaping on a light beam, an SLM projection optical system having a spatial light modulator (SLM) to shorten the modeling time And a so-called collective exposure optical system for forming each cured layer by projecting the pattern of each layer onto an ultraviolet curable resin.

  Next, as shown in FIG. 14, an optical modeling apparatus 51 having a beam scanning optical system and a batch exposure optical system will be described. In addition, in the following description, about the part which is common in the optical modeling apparatus 1 mentioned above, while attaching | subjecting a common code | symbol, detailed description is abbreviate | omitted.

  The optical modeling apparatus 51 having the beam scanning optical system and the batch exposure optical system described below is a high-definition modeling by changing the wavelength used and the configuration of the lens system of the beam scanning optical system to reduce the spot diameter. On the other hand, there is a limit to the intensity of the light source, and basically drawing is performed by scanning one light beam, so a relatively large area is irradiated with the light beam to form a hardened layer with a large area. In order to require a very long time, it is not suitable for forming a hardened layer in a large area, and it is not possible to draw one light beam of a batch exposure optical system by beam scanning. Therefore, it is possible to use, for example, an array-shaped light source, and it is possible to shorten the exposure time because the light source can be strengthened, while depending on the number of pixels of the spatial light modulator, etc. In view of the feature that the degree of accuracy is limited and the edge portion of each cured layer cannot be formed cleanly, that is, unsuitable for high-definition modeling, as described later, By combining the advantages and supplementing each other's disadvantages, it is possible to form relatively large objects with high definition.

  Specifically, as shown in FIG. 1, the optical modeling apparatus 51 holds a resin storage tank 3 storing the ultraviolet curable resin 2 and a cured layer 2 a formed by being immersed in the resin storage tank 3 on the lower surface side. At the same time, a movable gantry 4 that is movable at least in the vertical direction Z, a beam scanning optical system 10 for irradiating light onto the ultraviolet curable resin 2, a collective exposure optical system 60 and a focus detection optical system 35 described later are provided. And an optical system 55.

  Then, the optical modeling apparatus 51 sequentially repeats the operation of irradiating light with the optical system 55 to form a hardened layer on the lower surface of the movable mount 4 and the operation of moving the movable mount 4 upward in the vertical direction Z. Perform 3D modeling. When the first hardened layer is formed, a region where a predetermined gap is formed between the lower surface of the movable frame 4 and the upper surface of the transmission part 3a becomes the hardened layer forming surface, and the above-described hardening is performed. After the layer is formed, a region where a predetermined gap is formed between the hardened layer formed on the lower surface of the movable mount 4 and the upper surface of the transmission part 3a becomes the hardened layer forming surface.

  As described above, the transmission part 3a of the resin storage tank 3 functions as a liquid level regulating plate, and the optical modeling apparatus 51 having the transmission part 3a as the liquid level regulating plate is an ultraviolet curable resin 2 on the cured layer forming surface. The accuracy of the hardened layer formed by regulating the vibration, swinging, and the like, and the finally formed three-dimensional object are improved, that is, high-definition three-dimensional object modeling is possible.

  Further, the optical modeling apparatus 51 changes the relative position of the moving gantry 4 and the optical system 55 in the horizontal plane by the moving means 56 described later, so that the hardened layer is fixed with the moving gantry 4 and the optical system 55 fixed. It is possible to form a hardened layer having a larger area than the region where the film can be formed, that is, it is possible to form a large shaped article.

  As shown in FIG. 14, the stereolithography apparatus 51 is used as a drawing light source (beam scanning light source) that emits a light beam for drawing light on the ultraviolet curable resin 2 for the beam scanning optical system 10. 1 light source 11 and scanning means 12 for scanning a light beam emitted from the first light source 11 on the ultraviolet curable resin 2, and for the collective exposure optical system 60, a constant on the ultraviolet curable resin 2. A second light source 61 as a collective exposure light source that emits light emitted for each region, and a spatial light modulation unit that collectively exposes a predetermined region on the ultraviolet curable resin 2 with a light beam emitted from the second light source ( An SLM (Spatial Light Modulator) 62, and for the focus detection optical system 35, the ultraviolet curable resin 2 is cured at a wavelength different from that of the light beam emitted from the first light source 11. A focus detection light source 31 that emits a light beam of a certain wavelength, and further includes a light beam scanned by the scanning unit 12, light spatially modulated by the spatial light modulation unit 62, and the focus detection light source 31. A beam splitter 43 is provided as optical path combining means for combining the emitted light beam and guiding it onto the ultraviolet curable resin 2.

  Similarly to the optical modeling apparatus 1 described above, the optical modeling apparatus 51 includes the collimator lens 13 and the anamorphic lens 14 in order to configure the beam scanning optical system 10 together with the first light source 11 and the scanning unit 12. A beam expander 15, a focus adjustment lens 16, and a shutter 17.

  In addition, the structure of the scanning means 12 used here is the same as that of the case of the optical modeling apparatus 1 mentioned above, and the function of each component provided in this scanning means 12 is the case of the optical modeling apparatus 1 mentioned above. Is the same as that of the second relay lens 24 and the objective lens 42 except that a beam splitter 43 is provided in place of the wavelength selective mirror 41, that is, the second relay lens 24 and the objective lens 42 are provided. Since it is the same except for guiding the light beam from the relay lens 24 to the objective lens 42 via the beam splitter 43, detailed description thereof is omitted here. Further, the beam splitter 43 reflects the light beam from the focus detection light source 31 of the focus detection optical system 35 and guides it to the objective lens 42 side, and reflects the reflected light reflected by the hardened layer forming surface to produce the PSD 32. It also has the function of leading to

  In the optical modeling apparatus 51, the objective lens 42 images the spatially modulated light from the batch exposure optical system 60 described later on the ultraviolet curable resin 2. Further, the size of the work area in the optical modeling apparatus 51 is also determined by the spatial light modulation means 62 of the collective exposure optical system 60 described later.

  Further, the optical modeling apparatus 51 is configured so that the object-side focal position of the objective lens 42 is arranged to coincide with the reflection / transmission surface 43a of the beam splitter 43, as in the case of the optical modeling apparatus 1 described above. It is not necessary to exactly match, and it is only necessary that the object side focal position is positioned in the vicinity of the reflection / transmission surface 43a to such an extent that the beam splitter 43 itself does not become too large. That is, since the light beam and light from the beam scanning optical system 10 and the batch exposure optical system 60 need to pass (transmit or reflect) all through the reflection / transmission surface 43a, the beam splitter 43 does not become too large. The object side focal position of the objective lens 42 may be positioned in the vicinity of the reflection / transmission surface 43a.

  Further, in the stereolithography apparatus 51, the first and second relay lenses 23 and 24 need to synthesize an optical path with a batch exposure optical system 60 to be described later. The first and second galvanometer mirrors 21 and 22 need to be disposed closer to the first light source 11 than the beam splitter 43 and the objective lens 42 needs to be disposed closer to the ultraviolet curable resin 2. It is possible to prevent the two galvanometer mirrors 21 and 22 and the beam splitter 43 from physically colliding with each other due to the rotation of the reflecting means of the galvanometer mirror, that is, separating the distance from the colliding range. Make it possible.

  Here, the beam splitter 43 is disposed in order to match the irradiation optical paths of the beam scanning optical system 10 and the collective exposure optical system 60 described later, and by combining the optical paths with such a beam splitter 43, Both optical systems irradiate the work area with a light beam and light from the vertical direction, and prevent the inclined surface from being formed on each hardened layer by irradiating from the oblique direction inclined from the vertical direction. This is to achieve high-definition modeling. Here, as described above, the focus detection optical system 35 can also irradiate a focus detection light beam from a predetermined position and direction to perform accurate focus detection.

  Further, the objective lens 42 needs to be arranged on the ultraviolet curable resin 2 side from the beam splitter 43 because the beam splitter 43 becomes large if the objective lens 42 is arranged in front of the beam splitter 43. In addition, by disposing the objective lens 42 closer to the ultraviolet curable resin 2 than the beam splitter 43, an error in the irradiation position of the scanned light beam due to an increase in the distance from the objective lens 42 to the ultraviolet curable resin 2 or the like. This is because it is possible to prevent the occurrence of this problem.

  The beam scanning optical system 10 of the optical shaping apparatus 51 makes the light beam emitted from the first light source 11 substantially parallel by the collimator lens 13, beam-shaped by the anamorphic lens 14, and beam diameter by the beam expander 15. , The focus state is adjusted by the focus adjustment lens 16, and the first and second galvanometers are passed through the front focal position of the objective lens 42 by the first and second relay lenses 23 and 24. The beam is deflected so as to be scanned in the X and Y directions by the mirrors 21 and 22, guided to the objective lens 42 side by the beam splitter 43, and scanned to a desired position on the ultraviolet curable resin 2 by the objective lens 42. At the same time, it is condensed to irradiate and draw a fine region to form a hardened layer.

  At this time, in many conventional beam scanning type optical modeling apparatuses, the galvanometer mirror in the X direction and the galvanometer mirror in the Y direction are arranged close to each other to perform two-dimensional scanning. Since the apparatus 51 needs to be combined with a collective exposure optical system 60 described later, the light beam deflected by the first galvanometer mirror 21 in the X direction by the first relay lens 23 is placed on the second galvanometer mirror 22. An image is formed, and a light beam deflected by the second galvanometer mirror 22 in the Y direction is imaged on the object side focal point of the objective lens 42 by the second relay lens 24.

  In other words, the objective lens 42 needs to be provided with a beam splitter 43 for combining with the batch exposure optical system 60 described later between the first and second galvanometer mirrors 21 and 22 and the work position. The first and second relay lenses 23 and 24 are provided between the beam splitter 43 and the workpiece position, and the distance between the first and second galvanometer mirrors 21 and 22 and the workpiece position is increased. Even in this case, the light beam can be imaged with high accuracy at a predetermined position on the first and second galvanometer mirrors 21 and 22 and the work area, and telecentric imaging can be performed. Here, the workpiece position refers to a workpiece region, that is, a position where the ultraviolet curable resin 2 is provided on the movable frame 4.

  As described above, the optical modeling apparatus 1 enables desired fine drawing on the ultraviolet curable resin 2 by the beam scanning optical system 10 including the scanning unit 12 and the like as described above, and thereby the desired precision can be obtained with high accuracy. A hardened layer having a shape can be obtained, thus realizing high-definition modeling. The beam scanning optical system 10 can perform a raster scan, a vector scan, or a raster / vector combined scan, as described above.

  Similarly to the optical modeling apparatus 1, the optical modeling apparatus 51 is irradiated and reflected on the cured layer forming surface of the ultraviolet curable resin 2 in order to constitute the focus detection optical system 35 together with the focus detection light source 31 described above. A PSD 32 is provided as reflected light detecting means for detecting the detected light beam. Further, the focus detection optical system 35 of the optical modeling apparatus 51 includes a reflection mirror 36 that reflects the light beam emitted from the focus detection light source 31 and guides it to the beam splitter 43.

  Note that the configurations of the focus detection light source 31 and the PSD 32 constituting the focus detection optical system 35 provided in the optical modeling apparatus 51 are the same as those of the optical modeling apparatus 1 described above, and the focus detection optical system 35 is described above. Since the focus detection optical system 30 of the optical modeling apparatus 1 is different from the focus detection optical system 30 only in the arrangement and the optical path of the light beam for focus detection, its functions and effects are the same as those of the focus detection optical system 30. Omitted.

  That is, in the focus detection optical system 35, the light beam emitted from the focus detection light source 31 is reflected by the reflection mirror 36 and reflected by the beam splitter 43, thereby being guided to the objective lens 42, via the objective lens 42. The light beam guided to the interface between the transmitting portion 3a as the liquid level regulating plate and the ultraviolet curable resin 2 and reflected by this interface is guided to the PSD 32 via the objective lens 42 and the beam splitter 43, and received and focused. A state is detected. Further, in the optical modeling apparatus 51, the transmission part 3a provided at the bottom of the resin storage tank 3 is also configured in the same manner as the optical modeling apparatus 1 described with reference to FIG. 7 to FIG. 3a functions as a liquid level regulating plate, and a reflective coating film 7 is provided on the transmitting portion 3a.

  The optical modeling apparatus 51 including such a focus detection optical system 35 includes a focus detection light source 31 that emits a light beam having a wavelength different from that of the drawing light beam and a wavelength that does not cure the ultraviolet curable resin 2; The reflective coating film 7 is formed on the surface of the transmissive part 3a functioning as a liquid level regulating plate on the ultraviolet curable resin side, and the position of the cured layer forming surface is accurately and accurately provided. It can be detected reliably.

  In the optical modeling apparatus 51, the focus adjustment by the focus adjustment lens 16 of the beam scan optical system 10 based on the focus detection signal obtained by the focus detection optical system 35 is the same as that of the optical modeling apparatus 1 described above. Therefore, detailed description is omitted.

  The optical modeling apparatus 51 accurately detects the position of the hardened layer forming surface by the focus detection optical system 35 and performs focus adjustment by the focus adjustment lens 16 of the beam scan optical system 10 based on the obtained detection signal. Thus, the light beam for drawing can be condensed on the cured layer forming surface of the ultraviolet curable resin 2 with an appropriate spot diameter, and high-precision optical modeling can be performed.

  Moreover, since the optical modeling apparatus 51 can detect an accurate focus state in real time by the focus detection optical system 35, it can be configured to change the spot diameter according to the shape of the hardened layer to be formed. To do. In other words, the optical modeling apparatus 1 performs fine modeling by drawing with a reduced spot diameter for a portion that requires fine exposure, such as a contour portion of a target modeling object, by the control unit 101 described later. Thus, it may be configured to perform high-speed modeling by increasing the spot diameter and drawing the portion such as the center portion of the target modeling object, thereby enabling high-speed and high-definition optical modeling. Make it possible.

  It should be noted that the focus detection by the PSD 32 as the reflected light detection means and the focus correction by the focus adjustment lens 16 in the stereolithography apparatus 51 may be always performed, and at least every time each cured layer is formed, that is, The moving gantry 4 may be configured to be performed each time the moving gantry 4 is moved in the vertical direction Z. Further, the moving gantry 4 is moved in the horizontal directions X and Y for every predetermined divided area in the step & repeat operation described later. And / or it may be configured to be performed each time when it is moved in the vertical direction Z.

  Further, the optical modeling apparatus 51 includes a polarizing plate 63 for making predetermined polarized light and light passing therethrough in order to constitute the batch exposure optical system 60 together with the second light source 61 and the spatial light modulation means 62 described above. The beam integrator 64 for uniforming the light, the reflecting means 65 for guiding the light from the beam integrator 64 to the spatial light modulation means 62, and the light spatially modulated by the spatial light modulation means 62 as the front focal point of the objective lens 42. And a condensing lens 66 for condensing light.

  Here, between the second light source 61 and the polarizing plate 63, the passage / shielding of the light applied to the ultraviolet curable resin 2 is controlled, that is, the on / off control of exposure by the batch exposure optical system 60 is performed. A shutter 67 is provided.

  The second light source 61 as a collective exposure light source used in the collective exposure optical system 60 emits light that is irradiated for each predetermined region in the surface of the cured layer forming surface of the ultraviolet curable resin 2. This is an array of high output blue LEDs (Light Emitting Diodes). Unlike the beam scanning light source, the collective exposure light source need not use a coherent laser light source. The light emitted from the LED array which is the second light source 61 is made uniform by the beam integrator 64.

  As the beam integrator 64, it is possible to use a general type such as a fly eye type in which a plurality of lens elements are arranged, or a light rod type as a configuration that totally reflects the inside of a columnar rod lens such as a square column. It is. The light that has passed through the beam integrator 64 uniformly irradiates a transmissive liquid crystal element 68 described later.

  As the spatial light modulation means 62 of the optical modeling apparatus 1, for example, a transmissive liquid crystal element 68 having two transparent substrates stacked, a liquid crystal layer made of liquid crystal sealed between the transparent substrates, and a transparent electrode is provided. Used. This transmissive liquid crystal element 68 spatially modulates the light passing therethrough by changing the polarization direction of the transmitted light by changing the arrangement of the liquid crystal molecules corresponding to the image to be projected for each pixel based on the drive signal. Desired projection light can be projected onto the ultraviolet curable resin 2. Here, the image to be projected means projection light that becomes light corresponding to the shape to be collectively exposed. Here, the description has been made assuming that the transmissive liquid crystal element is used as the spatial light modulator 62, but the present invention is not limited to this, and a plurality of minute reflecting mirrors whose inclination angles change according to the input signal are arranged. A digital mirror micro device (DMD), a reflective liquid crystal element (LCOS), or the like may be used. When a digital mirror micro device (DMD) is used, each micro mirror corresponds to one pixel described later.

  Here, as the number of pixels of the transmissive liquid crystal element 68, one having 1 million pixels of 1000 × 1000 in length and width is used, and the size corresponding to each pixel on the work area that has passed through the condenser lens 66 and the objective lens 42. By setting the thickness to about 10 μm × 10 μm, the collective exposure optical system 60 having the transmissive liquid crystal element 68 has an area of 1 cm × 1 cm for each fixed area (10 μm × 10 μm) corresponding to each pixel. It is possible to perform batch exposure of predetermined areas to be exposed at once. As described above, the above-described work area is a 1 cm × 1 cm area that can be collectively exposed by the transmissive liquid crystal element 68 as the spatial light modulator. In addition, by increasing the number of pixels, it is possible to increase the accuracy of batch exposure by reducing the constant region corresponding to the one pixel described above, and to change the configuration of the condenser lens 66 and the objective lens 42. It is also possible to change the size of the work area. Furthermore, the spatial light modulation means 62 may be configured to change the number of used pixels or change the projection size for each layer or for each divided area described later according to desired shape data to be formed. .

  Further, the stereolithography apparatus 1 is configured such that the transmissive liquid crystal element 68 is used as the spatial light modulator 62 and the above-described polarizing plate 63 is used to enter the transmissive liquid crystal element 68 with predetermined polarized light. However, you may comprise so that it may enter with predetermined polarized light by another method.

  The condensing lens 66 is provided between the spatial light modulator 62 and the beam splitter 43, and together with the objective lens 42, images the light modulated by the spatial light modulator 62 on the ultraviolet curable resin 2. Functions as a projection optical system. The condensing lens 66 is composed of a lens group that corrects distortion when the light spatially modulated by the spatial light modulation means 62 passes through the objective lens 42, and not only functions as the projection optical system described above. Distortion can be reduced to the maximum. In other words, the condensing lens 66 needs to synthesize the beam scanning optical system 10 and the batch exposure optical system 60 as will be described later, so that the light from the batch exposure optical system 60 is reflected by the fθ lens of the beam scanning optical system 10. It is possible to prevent distortion that occurs due to passing through the objective lens 42.

  As described above, the second light source 61, the spatial light modulation means 62 such as a transmissive liquid crystal element, the polarizing plate 63, the beam integrator 64, the reflection means 65, the condenser lens 66, and the objective lens 42. Constitutes a collective exposure optical system 60. The collective exposure optical system 60 of the stereolithography apparatus 1 converts the light beam emitted from the second light source 61 into a predetermined polarized light by the polarizing plate 63, and a beam integrator 64. And is spatially modulated by the transmissive liquid crystal element 68 serving as the spatial light modulation means 62 so as to obtain projection light for performing predetermined exposure, and is condensed by the condenser lens 66 at the front focal position of the objective lens 42. The objective lens 42 irradiates the ultraviolet curable resin 2 so as to perform desired exposure.

  At this time, in the batch exposure optical system 60, the light spatially modulated by the spatial light modulation means 62 is condensed on the beam splitter 43 by the condensing lens 66, that is, at the front focal position of the objective lens 42. It is combined with the scanned light beam via the beam scanning optical system 10, imaged on the ultraviolet curable resin 2 by the objective lens 42, and irradiated onto a predetermined area. At this time, the distortion is reduced to the maximum by the condenser lens 66.

  Further, since the spatial light modulation means 62 can increase the light intensity of the emitted light because an LED array can be used as the second light source 61, the spatial light modulation means 62 is spatially modulated, A hardened layer can be formed in a predetermined time corresponding to the light intensity in the range formed by the condenser lens 66 and the objective lens 42, thereby enabling high-speed modeling.

  As described above, the optical modeling apparatus 51 uses the collective exposure optical system 60 including the spatial light modulation unit 62 and the like as described above, and the ultraviolet rays in the region included in the desired shape for each layer for obtaining a desired modeled object. It is possible to perform rough drawing, that is, rough drawing, within a predetermined range consisting of a certain area corresponding to one pixel on the curable resin 2, thereby forming a hardened layer in a certain range all at once, that is, in a short time. Therefore, high-speed modeling is realized by such batch drawing.

  Further, the batch exposure optical system 60 of the stereolithography apparatus 51 is also configured so that the focus can be adjusted according to the focus detection result detected by the focus detection optical system 35 described above. The focus adjustment in will be described.

  The above-described spatial light modulator 62 is provided with a focus adjustment drive unit 69. Specifically, the focus adjustment drive unit 69 performs control to be described later based on a focus detection signal obtained by the PSD 32. Based on the focus correction signal generated by the unit 101, the transmissive liquid crystal element 68 as the spatial light modulator 62 is moved in the optical axis direction.

  As described above, the drive unit 69 and the transmissive liquid crystal element 68 serve as a focus adjustment unit that adjusts the focus state of light projected onto the ultraviolet curable resin 2 by the collective exposure optical system 60, that is, the projection size of this light. Function. That is, based on the focus correction signal from the control unit 101, the transmissive liquid crystal element 68 that has been moved to a predetermined position by the drive unit 69 adjusts the projection size of light projected onto the ultraviolet curable resin 2 by the objective lens 42. be able to.

  As described above, the optical modeling apparatus 51 accurately detects the position of the hardened layer forming surface by the focus detection optical system 35, and based on the obtained detection signal, the drive unit 69 and the spatial light of the batch exposure optical system 60. By performing focus adjustment, that is, adjustment of the projection size by the focus adjustment unit comprising the modulation unit 62, exposure light for batch exposure can be exposed on the cured layer forming surface of the ultraviolet curable resin 2 with an appropriate projection size. And high-precision optical modeling can be performed.

  The optical modeling apparatus 51 synthesizes the optical path of the light beam scanned by the scanning unit 12 of the beam scanning optical system 10 and the light spatially modulated by the spatial light modulation unit 62 of the batch exposure optical system 60 by the beam splitter 43, By irradiating the ultraviolet curable resin 2 on the movable mount 4 via the objective lens 42, high-speed and high-definition modeling is realized.

  That is, the optical modeling apparatus 51 configured as described above irradiates the light beam scanned by the scanning unit 12 and the light spatially modulated by the spatial light modulation unit 62, or irradiates one of them. Both are possible, and higher-speed modeling is possible.

  At this time, since the light beam and the light from the beam scanning optical system 10 and the batch exposure optical system 60 are combined by the beam splitter 43, the optical beam is perpendicular to the ultraviolet curable resin 2 when using either optical system. Since it can irradiate from a direction, a hardened layer and a molded article do not incline in the diagonal direction with respect to a horizontal direction, and enable high-definition modeling.

  Further, the optical modeling apparatus 51 uses the spatial light modulation means 62 for a portion that can be exposed in a large amount according to the shape of each layer of the target three-dimensional object by the collective exposure optical system 60 that realizes a high speed. Irradiates light modulated spatially by high-speed modeling, and for a portion requiring high-definition modeling, such as a boundary portion, irradiates a light beam scanned by the scanning unit 12 to achieve high-definition. Enables fine modeling.

For example, when the target two-dimensional shape f ₁ that is the shape of each layer of the target three-dimensional modeled object as shown in FIG. 15 is in the work area, the optical modeling apparatus 1 performs spatial modulation by the spatial light modulation means 62. A portion that is a portion that is inside the desired shape for each layer to obtain a shaped object of a desired shape by performing collective exposure (collective drawing) with the emitted light, and that is a combination of each of the predetermined regions corresponding to the one pixel described above By performing rough drawing (hereinafter also referred to as “collective drawing”) (hereinafter also referred to as “collective drawing region”), one or a plurality of portions a ₁₁ cured corresponding to each pixel are combined. A boundary portion a _{21 having} a desired shape for each layer is formed by a light beam formed by forming a large portion a ₁ (hereinafter, also referred to as “collective drawing portion”) of the cured layer of the photocurable resin and scanned by the scanning unit 12. Between the roughly drawn part and the boundary part The gap section a ₂₂ (hereinafter, together with the boundary portion and the gap portion is also referred to as "fine drawing area.") Of the fine portion a ₂ of the cured layer of the photocurable resin by performing fine drawing _{(hereinafter,} (Also referred to as a “fine drawing portion”).

When fine drawing is performed by the beam scanning optical system 10 including the scanning unit 12 and the like, as shown in FIG. 16, the fine part a _{2 of the} hardened layer is repeatedly performed by repeatedly performing vector scanning on the boundary part a ₂₁ and the gap part a _22. it may form, and as shown in FIG. 17, the boundary portion a ₂₁ performs the vector monitor, may form a fine portion a ₂ of the hardened layer by performing a gap section a ₂₂ by raster scanning .

  Thus, the optical modeling apparatus 51 can form a hardened layer in a shorter time than a target optical modeling apparatus of the beam scan type as shown in FIG. The hardened layer can be formed with higher accuracy than that formed by the conventional stereolithography apparatus. Further, as described above, the optical modeling apparatus 1 moves the movable gantry 4 to the lower side in the vertical direction Z, and then moves the work region so that the work region is located at the position for forming the hardened layer. By repeating the operation to change the formation layer, a three-dimensional model can be formed, and by forming a high-precision hardened layer as described above in a short time, a high-precision model can be modeled in a short time. It becomes.

  In addition, as shown in FIG. 1, the stereolithography apparatus 51 to which the present invention is applied is one of the movable gantry 4 and the optical system 55 including the scanning unit 12, the spatial light modulation unit 62, the beam splitter 43, and the like. A moving means 56 for moving one side in the X direction and the Y direction in a plane parallel to the liquid level of the ultraviolet curable resin 2 is provided. Here, the moving means 56 is a moving means for driving the moving gantry 4 in the biaxial directions X and Y substantially perpendicular to each other in a plane parallel to the liquid surface of the ultraviolet curable resin 2, but is not limited thereto. Instead, the relative position may be changed by moving at least one of the movable frame 4 and the optical system 55. In addition, here, the movable gantry 4 is configured to move in a plane parallel to the liquid level with respect to the resin storage tank 3 as well. May be configured to move simultaneously.

  The moving means 56 moves the moving gantry 4 in the X direction and / or the Y direction, for example, and changes the relative positions of the moving gantry 4 and the optical system 55 in the horizontal plane. On the cured layer laminated thereon, the region where the cured layer can be formed can be changed in a plane parallel to the liquid surface, and thus the work region can be changed.

  In this way, the optical modeling apparatus 51 is driven and controlled by the control unit 101 described later, so that the relative positional relationship between the optical system 55 and the movable gantry 4 is expressed by X and Y by the movable gantry 4 and the moving means 56. , Z direction can be changed. In this example, the relative position relationship in the X, Y, and Z directions can be changed. However, for example, the movable mount 4 can be changed in the direction around the Z axis. In addition, with this configuration, it is possible to form a modeled object at high speed and with high definition.

  The optical modeling apparatus 51 sequentially repeats an operation of changing the relative position of the moving gantry 4 and the optical system 55 by the moving unit 56 and an operation of forming a hardened layer by the light and the light beam of the optical system 55. (Hereinafter, also referred to as “step and repeat operation”), it is possible to perform modeling in a wider range, that is, it is possible to model a larger modeled object with high definition.

  Here, the step & repeat operation will be described in detail. In the following description, it is assumed that a modeled object having a size within a plane parallel to the liquid level of the ultraviolet curable resin 2 is, for example, 10 cm × 10 cm or less is created by the optical modeling apparatus 1. The so-called height direction perpendicular to the liquid level of the modeled object is determined by the movable range of the movable mount 4 in the Z direction.

For example, as shown in FIG. 18, the stereolithography apparatus 51 that enables the step-and-repeat operation uses the 10 cm × 10 cm area as the entire work area W _all indicating the maximum area where each layer of the modeled object can be formed. This is divided into respective work areas W _xy composed of individual divided areas of, for example, 1 cm × 1 cm, and light and light beams are irradiated from the optical system 55 for each of the work areas W _xy , and a hardened layer is formed on the movable frame 4. Each of the hardened layers of the desired model is formed by sequentially changing the relative positions of the moving gantry 4 and the optical system 55 by the moving means 56 described above.

Specifically, when the target two-dimensional shape as indicated by “ _fall” in FIG. 18 is in the entire work area W _all , first, as shown in FIGS. in one of the work area W ₃₂ when the optical system 55 is a state located in the position facing the area W _32, performs rough drawing by the spatial light modulated by the spatial light modulation means 62 of the collective exposure optical system 60 As a result, the batch drawing portion a ₃₂₁ which is the majority of the hardened layer in the work area is formed, and the fine drawing by the light beam scanned by the scanning means 12 of the beam scanning optical system 10 is performed. A fine drawing portion a ₃₂₂ which is a fine portion of the cured layer is formed. This makes it possible to form a cured layer of a predetermined shape f ₃₂ in one work area W _32.

Then, by changing the relative position of the moving gantry 4 and the optical system 55 by the moving means 56, the optical system 55 is positioned at a position facing the other work area _Wxy on the moving gantry 4. . Also in the work area W _xy, the hardened layer was formed in the same manner as the work area W ₃₂ described above, by repeating this step-and-repeat operation, it is possible to form one layer of each cured layer of build material. And as above-mentioned, after moving the movable mount frame 4 to a Z direction, performing the above-mentioned step & repeat operation | movement can be repeated sequentially, and a molded article can be formed by laminating | stacking each hardening layer.

  As described above, the stereolithography apparatus 51 that includes the moving unit 56 that changes the relative position between the movable gantry 4 and the optical system 55 and that performs the step-and-repeat operation can perform a high-definition and short-time operation in a relatively large area. Can be cured, thereby making it possible to form a relatively large three-dimensional model.

  In the above description, in a predetermined small area of about 1 cm × 1 cm, rough drawing is performed by the batch exposure optical system 60 on the order of about 10 μm, fine drawing is performed by the beam scanning optical system 10 on the order of about 1 μm, and step Although a relatively large model of about 10 cm × 10 cm is realized by performing the & repeat operation, it is possible to realize modeling of a larger model by moving the moving frame 4 and the like over a wider range by the moving means 56. At the same time, finer drawing can be realized by changing the number of pixels of the spatial light modulating means 62 of the batch exposure optical system 60 or changing the configuration to form a smaller beam spot by the beam scanning optical system 10.

  By the way, the optical modeling apparatus 51 to which the present invention is applied includes a control device 100 as in the optical modeling apparatus 1 described above. The control apparatus 100 includes a control unit 101 and an input as shown in FIG. A unit 102 and an operation unit 103 are provided.

  As shown in FIG. 20, the control unit 101 performs laser control on the first light source 11, controls light beam transmission and shielding on the shutter 17, and performs first and second galvanometer mirrors 21. , 22 to control the rotational drive of the reflecting means, the fine drawing of the beam scanning optical system 10 is controlled.

  In the stereolithography apparatus 51, the control unit 101 controls the light intensity and the like with respect to the second light source 61, controls light transmission and shielding with respect to the shutter 67, and controls the spatial light modulation unit 62. By performing the control, the batch drawing of the batch exposure optical system 60 is controlled.

  Further, the control unit 101 controls the moving means 56 to move the moving gantry 4 in the X and Y directions so that the work area is located at a predetermined position of the moving gantry 4 corresponding to the predetermined divided area. When the stacking of the divided areas at the predetermined position is completed, the movable gantry 4 is moved in the X and Y directions so that the work area is located at a predetermined position of the movable gantry 4 corresponding to the next predetermined divided area. Further, when the stacking of the hardened layers having a predetermined height is completed, the control unit 101 controls the moving gantry 4 to raise the moving gantry 4 in the vertical direction Z by a predetermined amount so that the position of the work area in the Z direction is increased. Change and change the formation layer.

  Further, the control unit 101 receives the focus detection signal detected by the PSD 32, generates a focus correction signal based on the focus detection signal, and outputs the focus correction signal to the focus adjustment driving unit 25, thereby causing the focus adjustment lens 16 to move. It is possible to control and correct the focus to adjust the focus state, thereby realizing further high-definition modeling.

  Furthermore, the control unit 101 receives the focus detection signal detected by the PSD 32, generates a focus correction signal based on the focus detection signal, and outputs the focus correction signal to the focus adjustment drive unit 69, thereby generating spatial light modulation means. 62 can be driven and controlled in the optical axis direction to perform focus correction and adjust the focus state. That is, the batch exposure optical system 60 can adjust the projection size of the exposure light on the cured layer forming surface. Achieving higher-definition modeling.

  The stereolithography apparatus 51 to which the present invention is applied is a first light source as a drawing light source that emits a light beam having a predetermined wavelength for forming a cured layer by drawing the ultraviolet curable resin 2 on the cured layer forming surface. 11, scanning means 12 for scanning the ultraviolet curable resin 2 with the light beam emitted from the first light source 11, and the ultraviolet curable resin 2 at a wavelength different from that of the light beam emitted from the first light source 11. A focus detection light source 31 that emits a light beam having a wavelength that does not cure, and irradiates the cured layer forming surface with the light beam emitted from the focus detection light source 31 and reflects the light beam reflected by the cured layer formation surface. By adjusting the focus state of the light beam scanned by the scanning means 12 with the light detected by the reflected light detection means such as PSD 32, the light beam for drawing is made of the ultraviolet curable resin 2. Layer appropriate spot diameter on the forming surface at can be condensed, it realizes to make a high-definition optical shaping to improve the molding accuracy. That is, the stereolithography apparatus 1 to which the present invention is applied accurately detects a focus using a light beam for focus detection, and uses a light curable resin with an appropriate spot diameter by a drawing light beam according to the detection result. High-definition 3D modeling is realized by performing this exposure. Moreover, the optical modeling apparatus 51 has the same effect as the effects of the optical modeling apparatus 1 described above.

  Furthermore, the stereolithography apparatus 51 to which the present invention is applied includes the first light source 11, the scanning unit 12, and the focus detection light source 31, and further emits light that is irradiated for each predetermined region of the ultraviolet curable resin 2. A second light source 61 as a collective exposure light source to be radiated; and spatial light modulation means 62 that spatially modulates the light emitted from the second light source 61 to collectively expose a predetermined region on the ultraviolet curable resin 2; By curing the ultraviolet curable resin 2 with the light beam scanned by the scanning means 12 and the light spatially modulated by the spatial light modulating means 62, each cured layer is formed, that is, each desired cured layer is formed. For the parts that can be exposed at the same time when forming, a hardened layer is formed in a short time using light that is spatially modulated by the spatial light modulation means 62, and fine precision around the boundary and the boundary is required. Part With respect to, by forming a hardened layer with high accuracy by the light beam scanned by the scanning means 12, each hardened layer of the modeled object can be formed at high speed and with high accuracy, and by stacking these layers, high definition is achieved. It is possible to form a simple three-dimensional model in a short time. Furthermore, the optical modeling apparatus 51 can improve the accuracy of the light beam scanned by the scanning unit 12 of the beam scanning optical system 10 by performing the above-described accurate focus detection, and can achieve a higher-definition three-dimensional modeled object. Can be formed in a short time.

  In addition to the first light source 11, the scanning unit 12, the second light source 61, and the spatial light modulation unit 62, the optical modeling apparatus 51 to which the present invention is applied includes any one of the optical system 55 and the movable mount 4. By moving one of them in a plane parallel to the liquid level, and moving means 56 for changing the relative position of the moving gantry 4 and the optical system 55, a light beam scanned by the scanning means 12 is provided. The operation of forming a divided shape obtained by dividing the desired two-dimensional shape in each work area by the light spatially modulated by the spatial light modulation means 62, and the relative of the moving gantry 4 and the optical system 55 by the moving means 56. By performing so-called step-and-repeat operation that sequentially repeats the operation of changing the position, each cured layer larger than the work area determined by the performance of the scanning means 12 and the spatial light modulation means 62 can be quickly and highly accurate. Can be formed by laminating them, it realizes to form a relatively large three-dimensional object with high definition and in a short time.

  Furthermore, the optical modeling apparatus 51 to which the present invention is applied irradiates the cured layer forming surface with the light beam emitted from the focus detection light source 31, and detects the reflected light from the cured layer forming surface such as PSD 32. By adjusting the focus state of the light spatially modulated by the spatial light modulation means 62 with the light detected by the means, the light for batch exposure is photocured with an appropriate projection size on the cured layer forming surface of the ultraviolet curable resin 2 By performing the exposure of the photosensitive resin, the accuracy can be increased also for the portion where the hardened layer is formed by the batch exposure optical system 60, and a higher-definition three-dimensional model can be formed in a shorter time.

  The above-mentioned stereolithography apparatuses 1 and 51 use a so-called liquid level regulating method, and the function as a liquid level regulating plate is exhibited in the transmission part 3a provided at the bottom of the resin reservoir 3 so as to store the resin. Form in which a hardened layer is formed between the movable frame 4 and the transmitting portion 3a at the bottom, that is, the lower surface of the movable frame 4 by making an exposure light beam or light incident from the bottom side of the tank 3 However, the optical modeling apparatus to which the present invention is applied is not limited to this. For example, as shown in FIG. In this case, a liquid level regulating plate is provided in the vicinity of the liquid level of the resin reservoir 3, and an exposure light beam and / or light is incident on the upper side of the liquid level regulating plate, whereby the upper surface of the movable mount 4 is placed. It is good also as a structure which forms a hardened layer.

  That is, the stereolithography apparatus 71 shown in FIG. 21A holds the resin storage tank 3 storing the ultraviolet curable resin 2 and the cured layer 2a formed by being immersed in the resin storage tank 3 on the upper surface side. At least the movable frame 4 that is movable in the vertical direction Z perpendicular to the liquid surface that is the surface of the ultraviolet curable resin 2, and the optical system 5 for irradiating the ultraviolet curable resin 2 with light or And an optical system 55. The optical system used in this stereolithography apparatus 71 may be any of the optical systems 5 and 55 described above, and the configuration and function of the optical system are the same as described above, and thus detailed description thereof is omitted.

  This stereolithography apparatus 71 is transparent above the moving gantry 4 and near the liquid surface of the resin reservoir 3 and transmits the curing light from the optical systems 5 and 55 and functions as a liquid level regulating plate. It has a plate 72 and forms a cured layer by irradiating light from the optical systems 5 and 55 to a cured layer forming surface which is a region for forming a cured layer of the ultraviolet curable resin 2 through the transparent plate 72. . In other words, a predetermined gap is formed between the upper surface of the movable gantry 4 or the hardened layer formed on the upper surface of the movable gantry 4 and the lower surface of the transparent plate 72, and exists in the predetermined gap. The ultraviolet curable resin 2 is exposed to light from the optical systems 5 and 55 to form a cured layer forming surface on which a cured layer is formed. In addition, the transparent plate 72 forms a gap as a hardened layer forming surface between the upper surface of the movable frame 4 or a cured layer formed on the upper surface of the movable frame 4, and the vibration and vibration of the ultraviolet curable resin 2 therebetween. It functions as a liquid level regulating plate that regulates not to cause movement or the like.

  Then, the stereolithography apparatus 71 performs a three-dimensional operation by sequentially repeating an operation of irradiating light with an optical system to form a hardened layer on the upper surface of the movable mount 4 and an operation of moving the movable mount 4 downward in the vertical direction Z. Perform modeling.

  Similarly to the optical modeling apparatuses 1 and 51 described above, the optical modeling apparatus 71 to which the present invention is applied includes the first light source 11, the scanning unit 12, and the focus detection light source 31 as a drawing light source, and focus detection. The light beam emitted from the light source 31 is irradiated onto the hardened layer forming surface, and the light beam scanned by the scanning means 12 is detected by the light detected by the reflected light detecting means such as PSD 32. By adjusting the focus state, the drawing light beam can be condensed on the cured layer forming surface of the ultraviolet curable resin 2 with an appropriate spot diameter, and the modeling accuracy is improved and high-precision optical modeling is performed. Realize that.

  Moreover, although the above-mentioned stereolithography apparatus 1,51,71 uses what is called a liquid level control method, the stereolithography apparatus to which this invention is applied is not restricted to this, For example, FIG. As shown in b), a so-called free liquid level method may be used.

  That is, the optical modeling apparatus 76 shown in FIG. 21B holds the resin storage tank 3 storing the ultraviolet curable resin 2 and the cured layer 2a formed by being immersed in the resin storage tank 3 on the upper surface side. At least the movable frame 4 that is movable in the vertical direction Z perpendicular to the liquid surface that is the surface of the ultraviolet curable resin 2, and the optical system 5 for irradiating the ultraviolet curable resin 2 with light or And an optical system 55. The optical system used in this stereolithography apparatus 71 may be any of the optical systems 5 and 55 described above, and the configuration and function of the optical system are the same as described above, and thus detailed description thereof is omitted.

  This stereolithography apparatus 76 moves the movable gantry 4 in the vertical direction Z in the resin storage tank 3, so that the hardened layer located on the uppermost side of the movable gantry 4 or the cured layer already laminated on the movable gantry 4. The upper surface is positioned below the liquid surface of the ultraviolet curable resin 2 by a distance corresponding to the thickness of the cured layer, so that the ultraviolet curable resin 2 on the movable gantry 4 or the cured layer already laminated thereon is provided. A cured layer is formed by irradiating light from the optical systems 5 and 55 from above. Here, the liquid surface of the ultraviolet curable resin becomes the cured layer forming surface. In this stereolithography apparatus 76, the light beam emitted from the focus detection light source 31 is reflected by the resin liquid surface, which is the hardened layer forming surface, and the focus state is detected by detecting this reflected light with the PSD 32. It will be.

  Then, the stereolithography apparatus 76 three-dimensionally repeats an operation of irradiating light with an optical system to form a hardened layer on the upper surface of the movable mount 4 and an operation of moving the movable mount 4 downward in the vertical direction Z. Perform modeling.

  The optical modeling apparatus 76 to which the present invention is applied includes the first light source 11, the scanning unit 12, and the focus detection light source 31 as a drawing light source, as in the optical modeling apparatuses 1 and 51 described above, and performs focus detection. The light beam emitted from the light source 31 is irradiated onto the hardened layer forming surface, and the light beam scanned by the scanning means 12 is detected by the light detected by the reflected light detecting means such as PSD 32. By adjusting the focus state, the drawing light beam can be condensed on the cured layer forming surface of the ultraviolet curable resin 2 with an appropriate spot diameter, and the modeling accuracy is improved and high-precision optical modeling is performed. Realize that. Note that the optical modeling apparatuses 71 and 76 may be configured to further include moving means such as the moving means 56 of the optical modeling apparatus 51 described above.

  Next, an optical modeling method using the optical modeling apparatus as described above will be described. In addition, below, the optical modeling method using the optical modeling apparatus 51 demonstrated using FIG. 14 is demonstrated, and the optical modeling method using the optical modeling apparatus 1 demonstrated using FIG. 2 is demonstrated below. Since it is the same as the case of the optical modeling apparatus 51 except using the batch exposure optical system 60 and the moving means 56, detailed description is abbreviate | omitted.

  In the stereolithography method to which the present invention is applied, a cured layer is sequentially formed by irradiating light onto the ultraviolet curable resin 2 as a liquid photocurable resin based on the three-dimensional shape data input by the input means. Thus, a shaped article having a desired shape is formed.

In this stereolithography method, as shown in FIG. 22, step S1 of inputting three-dimensional shape data by the input unit 102, and step of generating two-dimensional shape data for each layer based on the input three-dimensional shape data S2 and step S3 for generating divided region shape data for each of the plurality of divided regions obtained by dividing each layer in a plane parallel to the liquid surface based on the generated two-dimensional shape data, and each generated divided region shape Based on the data, first data for forming a predetermined region by batch exposure by the batch exposure optical system 60 and second data for forming a remaining region by fine drawing by the beam scan optical system 10 Based on the first data while performing the focus adjustment based on the focus detection information obtained by the focus detection optical system 35. As well as batch exposure by batch exposure optical system 60, having based on the second data, and a step S5 of sequentially forming a cured layer by forming the divided regions W _xy finely drawn by the beam scanning optical system 10 .

  In step S <b> 1, three-dimensional shape data such as CAD data of a desired three-dimensional object having a desired shape is input into the control unit 101 of the control device 100 by the input unit 102.

  In step S2, the input three-dimensional shape data is converted into three-dimensional shape data such as an STL format, and the three-dimensional shape data is sliced in the Z direction, which is the stacking direction. Two-dimensional shape data is generated. In addition, you may comprise so that the arrangement | positioning attitude | position and orientation of a three-dimensional molded item and the lamination direction can be selected by this operation part 103, or the thickness of a lamination direction can be selected.

In step S3, based on the generated two-dimensional shape data, which is divided into divided regions corresponding to each of the predetermined work area W _xy of 1 cm × 1 cm as described above, two-dimensional shape of each work area W _xy The divided region shape data which is the data f _xy is generated.

In step S4, based on the obtained divided area shape data for each work area W _xy , a predetermined area is formed by batch exposure, that is, a certain area on the ultraviolet curable resin 2 by the spatial light modulation means 62. First data for forming a batch drawing portion which is a predetermined region of the hardened layer by batch exposure for each time, and forming a remaining region by fine drawing by the beam scanning optical system 10, that is, scanning means By scanning the light beam on the curable resin in step 12, the second data for forming the fine drawing portion which is the remaining region of the cured layer is generated.

  In steps S3 and S4 described here, after the divided area shape data is generated from the two-dimensional shape data, the first data and the second data are generated based on the divided area shape data. However, the present invention is not limited to this. Based on the two-dimensional shape data, the first data for forming a batch drawing portion which is a predetermined area by batch exposure using the batch exposure optical system and the beam scan optical system The second data for forming the fine drawing portion for forming the remaining area by drawing is generated, and then the divided area shape data of the first and second data is respectively generated. May be.

In step S5, as shown in FIG. 23, in each work area _Wxy , the light beam emitted from the light source 31 for focus detection is irradiated to the hardened layer forming surface, and the light beam reflected by the hardened layer forming surface is detected. Then, based on the first data and the focus result, the spatial light modulation means 62 spatially modulates the light so that a predetermined area on the ultraviolet curable resin 2 is collectively exposed while adjusting the focus state (projection size), and Based on the second data and the focus detection result, step S5-1 of forming a divided portion of the cured layer by scanning the light beam on the ultraviolet curable resin 2 while adjusting the focus state by the scanning unit 12, by the moving means 56, by changing the relative position between the optical system 55 and the moving platform 4 and step S5-2 of changing the work area W _xy, the Step S5-3 for confirming that the lamination of each divided region in the layer is completed, and when the hardened layer of the same layer having a predetermined height is formed, the movable base 4 is moved upward in the Z direction to form the layer Step S5-4, and step S5-5 for confirming that all the hardened layers have been stacked.

  In step S5-1, a focus detection light beam is emitted from the focus detection light source 31, and the focus detection light beam reflected by the cured layer forming surface of the ultraviolet curable resin 2 is detected by the PSD 32 to detect a focus detection signal. The light beam is emitted from the first light source 11 for drawing on the ultraviolet curable resin 2, and the light beam emitted from the first light source 11 is focused on the basis of the focus detection signal by the scanning unit 12. The second light source 61 emits light to be irradiated for each predetermined region on the ultraviolet curable resin 2, and the light emitted from the second light source 61 is emitted from the spatial light modulator 62 by the focus detection signal. The projection size (focus state) is adjusted on the basis of the light intensity and spatial modulation is performed. By scanning the resin 2 and exposing a predetermined area on the ultraviolet curable resin 2 with the light spatially modulated by the spatial light modulation means 62, the ultraviolet curable resin 2 in each divided area is cured, A divided region of each hardened layer is formed.

In step S5-2, the moving platform 4 is moved in the X and / or Y direction work area W _xy is set to be a position corresponding to the divided area shape data by the moving means 56.

  In step S5-3, it is confirmed whether or not the lamination of all the divided regions in the same layer is completed. If the stacking of the divided areas has not been completed, the process returns to step S5-1, and steps S5-1 and S5-2 are repeated. When the lamination of all the divided areas in the same layer is completed, the process proceeds to step S5-4.

In step S5-4, the movable gantry 4 is moved to the upper side in the vertical direction Z and then moved so that the work area _Wxy is positioned at a position for forming the hardened layer, thereby changing the formation layer.

  In step S5-5, it is confirmed whether or not the lamination of all the hardened layers of the three-dimensional structure has been completed. When the lamination | stacking of all the hardened layers of a three-dimensional molded item is not completed, it returns to step S5-1 and repeats steps S5-1 to S5-4.

Thus, in step S5, as described in step S5-1~ step S5-3 described above, collective exposure optical based on the first data to each work area W each _xy in the same layer of a predetermined height Based on the two-dimensional shape data by performing batch exposure by the system 60 and finely drawing by the beam scan optical system 10 based on the second data to form a divided region of the hardened layer and sequentially changing the work region. When all the divided regions in the same layer are formed and one layer of the hardened layer is obtained, the three-dimensional structure is formed by changing the height in the vertical direction Z and sequentially repeating this.

  In the above-described optical modeling method, when the moving unit 56 is not provided in the optical modeling apparatus 1, or when the size of the three-dimensional model to be modeled is small enough to be included in the predetermined work area. Step S3 may not be provided. In this case, the “two-dimensional shape data” generated in Step S2 becomes “divided region shape data” after S4, and Steps S5-2 and S5-2 in Step S5 S5-3 is not performed.

  As described above, the stereolithography method to which the present invention is applied is a drawing light source that emits a light beam of a predetermined wavelength for forming a cured layer by drawing the ultraviolet curable resin 2 on the cured layer forming surface. From each of the first light source 11 and the focus detection light source 31 that emits a light beam having a wavelength different from that of the light beam emitted from the first light source 11 and not curing the ultraviolet curable resin 2. By irradiating the light beam emitted from the light source 31 for focus detection onto the cured layer forming surface of the ultraviolet curable resin 2 and detecting the light beam reflected by the cured layer forming surface, the first beam is emitted. By adjusting the focus state by the scanning unit 12 that scans the ultraviolet light curable resin 2 with the light beam emitted from the light source 11 and scanning the cured layer forming surface, the optical beam for drawing is drawn. Beam to can be condensed with the appropriate spot diameter on the hardened layer forming surface of the ultraviolet curable resin 2, it realizes to make a high-definition optical shaping to improve the molding accuracy. That is, the stereolithography method to which the present invention is applied accurately detects the focus using the light beam for focus detection, and uses the light beam for drawing according to the detection result to make the photocurable resin with an appropriate spot diameter. High-definition three-dimensional modeling is realized by performing exposure.

  Further, in the stereolithography method to which the present invention is applied, a light beam is emitted from the first light source 11 to draw on the ultraviolet curable resin 2, and the light beam emitted from the first light source 11 is emitted by the scanning unit 12. Scanning means 12 emits light emitted from the second light source 61 for each predetermined region on the ultraviolet curable resin 2, and the light emitted from the second light source 61 is spatially modulated by the spatial light modulation means 62, and the scanning means 12. By drawing light on the ultraviolet curable resin 2 with the light beam scanned by the above, and exposing a predetermined region on the ultraviolet curable resin 2 with the light spatially modulated by the spatial light modulation means 62, each cured layer of the modeled object By forming the desired cured layer, a portion that can be exposed in a lump is formed using a light that is spatially modulated by the spatial light modulator 62 in a short time, For the parts that require fine accuracy near the boundary and boundary portions, each cured layer of the model is formed at high speed and with high accuracy by forming the cured layer with high accuracy by the light beam scanned by the scanning means 12. It is possible to form a three-dimensional shaped object in a short time by stacking these.

  In addition, the stereolithography method to which the present invention is applied includes a collective exposure light source that emits collective exposure light for forming a cured layer by irradiating the ultraviolet curable resin 2 on the cured layer forming surface for each predetermined region. The light beam is emitted from each of the second light source 61 and the focus detection light source 31, and the light beam emitted from the focus detection light source 31 is emitted to the cured layer forming surface of the ultraviolet curable resin 2 to be cured. By detecting the light beam reflected by the layer forming surface, the light emitted from the second light source 61 is spatially modulated to the ultraviolet curable resin 2 and the focus state is adjusted by the spatial light modulation means 62 that performs batch exposure. By scanning the cured layer forming surface, the batch exposure light is obtained by exposing the photocurable resin to an appropriate projection size on the cured layer forming surface of the UV curable resin 2 with the light for batch exposure. Also it can improve the accuracy for parts hardened layer is formed by the system 60, to achieve the formation in a shorter time the higher resolution three-dimensional object.

  Further, the stereolithography method to which the present invention is applied has a desired shape by sequentially irradiating light on the ultraviolet curable resin 2 to form a cured layer based on the three-dimensional shape data input by the input unit 102. An optical modeling method for forming a modeled object, in which step S1 inputs three-dimensional shape data by the input unit 102, and step S2 generates two-dimensional shape data for each layer based on the input three-dimensional shape data. Based on the two-dimensional shape data, the first data for forming a predetermined region of the cured layer by collectively exposing the ultraviolet curable resin 2 on the ultraviolet curable resin 2 for each predetermined region based on the two-dimensional shape data, and the scanning unit 12 To generate the second data for forming the remaining region of the cured layer by scanning the light beam on the ultraviolet curable resin 2 and the focus detection optical system 35. While performing focus adjustment based on the obtained focus detection information, based on the first data, spatial light is spatially modulated by the spatial light modulation means 62 and a predetermined area on the ultraviolet curable resin 2 is collectively exposed, Based on the second data, the scanning means 12 scans a light beam onto the ultraviolet curable resin 2 to sequentially form a cured layer, thereby enabling each cured layer of the model to be formed at high speed and high accuracy. By sequentially laminating these, it is possible to form a high-definition three-dimensional model in a short time.

  Moreover, the stereolithography method to which the present invention is applied is based on the three-dimensional shape data input by the input unit 102, and the ultraviolet curable resin 2 is irradiated with light to sequentially form a cured layer, thereby forming the ultraviolet curable resin. In an optical modeling method for forming a modeled object having a desired shape on a movable gantry 4 that is immersed in 2 and moved in a direction orthogonal to at least the liquid surface of the photocurable resin, three-dimensional shape data is input by the input unit 102. Step S1 for inputting, Step S2 for generating two-dimensional shape data for each layer based on the inputted three-dimensional shape data, and a plane parallel to the liquid surface based on the two-dimensional shape data for each layer Step S3 for generating divided region shape data for each of the plurality of divided regions and a predetermined region on the ultraviolet curable resin 2 by the spatial light modulator 62 based on the divided region shape data. The first data for forming a predetermined region of the divided region of the hardened layer by performing the batch exposure to the first and the remaining region of the hardened layer divided region by scanning the light beam on the ultraviolet curable resin 2 by the scanning means 12 The spatial light modulating means 62 based on the first data while performing the focus adjustment based on the focus detection information obtained by the focus detection optical system 35 in step S4 for generating the second data for forming The light is spatially modulated by the above and a predetermined area on the ultraviolet curable resin 2 is collectively exposed, and each divided area is scanned by scanning the light beam on the ultraviolet curable resin 2 by the scanning means 12 based on the second data. The work area is formed by sequentially changing the positional relationship in the plane parallel to the liquid level of the spatial light modulation means 62 and the scanning means 12 and the movable frame 4. Step S5 for sequentially forming and laminating the cured layers obtained by the change, each divided region of each cured layer of the modeled object can be formed at high speed and with high accuracy, whereby the modeled object can be formed at high speed and at high speed. It can be formed with high accuracy, and by sequentially laminating these, it is possible to form a relatively large three-dimensional object in a high definition and in a short time.

It is sectional drawing which shows the outline of the optical modeling apparatus to which this invention is applied. It is a figure which shows the optical system of the optical modeling apparatus to which this invention is applied. It is a figure for demonstrating the function of the objective lens which comprises the stereolithography apparatus to which this invention is applied, and is a schematic diagram at the time of using an f (theta) lens as an objective lens. It is a figure for demonstrating the function of the 1st and 2nd galvanometer mirror and objective lens which comprise the stereolithography apparatus to which this invention is applied, and is a schematic diagram of a 1st galvanometer mirror and an objective lens. It is a figure for demonstrating the function of the 1st and 2nd relay lens which comprises the optical modeling apparatus to which this invention is applied, and is a schematic diagram which shows an example of a both-side telecentric imaging optical system. It is a figure explaining the beam scanning system in the beam scanning optical system etc. of the optical modeling apparatus to which this invention is applied, (a) is a top view which shows a raster scan, (b) is a plane which shows a vector scan. It is a figure and (c) is a top view which shows a raster vector combined use scan. It is a figure for demonstrating the structure of the permeation | transmission part of the bottom part of the resin storage tank which comprises an optical modeling apparatus, and is an expanded sectional view which shows that the reflective coating film was formed in the ultraviolet curable resin side. FIG. 8 is a diagram for explaining the example of the reflective coating film shown in FIG. 7 in more detail, and is an enlarged cross-sectional view showing the reflective coating film formed by a laminated structure. As an example of the reflective coating film, the reflected light with respect to the wavelength of the incident light beam is reflected by a reflective coating film consisting of 10 layers in which five layers of 125 nm of MgF ₂ and 90 nm of ZrO ₂ are alternately stacked. It is a figure which shows the change of an intensity | strength. It is a figure which shows the other example about the structure of the permeation | transmission part of the bottom part of the resin storage tank which comprises a stereolithography apparatus, and is an expansion of the example which formed the peeling coating film and the antireflection coating film in addition to the above-mentioned reflective coating film It is sectional drawing. It is a figure explaining the focus detection using the triangulation method by the focus detection optical system which comprises an optical modeling apparatus, (a) is a top view which shows the detection position of the return light of the state of a just focus, (b) These are top views which show the detection position of the return light at the time of reflecting in the back | inner side position with respect to the state of just focus. It is a figure explaining the focus adjustment lens which comprises a stereolithography apparatus, (a) is a top view of the state which radiate | emits the incident light beam as convergent light with a focus adjustment lens, (b) is incident FIG. 4C is a plan view of a state in which the focused light beam is emitted as parallel light by the focus adjustment lens, and FIG. 5C is a plan view of a state in which the incident light beam is emitted as divergent light by the focus adjustment lens. It is a figure for demonstrating the control apparatus which controls the optical system of the optical modeling apparatus to which this invention is applied, and data processing. It is a figure which shows the example provided with a beam scanning optical system and a package exposure optical system as another example of the optical system of the optical modeling apparatus to which this invention is applied. It is a figure for explaining batch drawing and fine drawing when forming each cured layer of a three-dimensional object to be targeted by an optical modeling apparatus to which the present invention is applied, and a target two-dimensional shape that is the shape of each layer; It is a top view which shows a batch drawing part and a fine drawing part. It is a figure for demonstrating collective drawing and fine drawing at the time of forming each hardening layer of the target three-dimensional molded item with the optical modeling apparatus to which this invention is applied, while performing collective drawing by collective exposure, and vector scanning It is a top view which shows performing fine drawing by the beam scan of a system. It is a figure for demonstrating collective drawing and fine drawing when forming each hardening layer of the target three-dimensional modeled object with the optical modeling device to which the present invention is applied. It is a top view which shows performing fine drawing by the beam scan of a raster combined system. It is a figure for demonstrating the step & repeat operation | movement by the stereolithography apparatus to which this invention is applied, and is a top view for demonstrating dividing | segmenting the whole workpiece | work area | region for every predetermined | prescribed work area | region. Is a plan view showing one of the work area W ₃₂ of each of the work areas divided to work entire area shown in FIG. 18. It is a figure for demonstrating the control apparatus which performs control of the optical system of a stereolithography apparatus shown in FIG. 14, and data processing. It is a figure which shows the other example of the optical system of the optical modeling apparatus to which this invention is applied, (a) uses the liquid level regulation method, and is the liquid of the photocurable resin stored by the resin storage tank It is a figure which shows the outline of the stereolithography apparatus of the example which provides the light for exposure from the upper side of a liquid level control board by providing a liquid level control board in the surface vicinity, (b) uses what is called a free liquid level method. It is a figure which shows the outline of the optical modeling apparatus of the example which was. It is a flowchart explaining the optical modeling method to which this invention is applied. It is a flowchart for demonstrating in more detail about step S5 which forms the hardened layer shown in FIG. It is sectional drawing which shows the outline of the optical modeling apparatus using the conventional free liquid level method. It is sectional drawing which shows the outline of the optical modeling apparatus using the conventional liquid level control method. It is a figure for demonstrating the problem in the case of performing focus detection with the optical modeling apparatus using the conventional liquid level control method.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Stereolithography apparatus, 2 Ultraviolet curable resin, 3 Resin storage tank, 3a Transmission part, 4 Moving mount, 5 Optical system, 10 Beam scan optical system, 11 1st light source, 12 Scan means, 13 Collimator lens, 14 Anamol Fick lens, 15 beam expander, 16 focus adjustment lens, 17 shutter, 21 first galvanometer mirror, 22 second galvanometer mirror, 23 first relay lens, 24 second relay lens, 30 focus detection optical system, 31 focus detection light source, 32 PSD, 41 wavelength selective mirror, 42 objective lens, 43 beam splitter, 55 optical system, 56 moving means, 60 batch exposure optical system, 61 second light source, 62 spatial light modulation means, 63 Polarizing plate, 64 beam interior Regulator, 65 reflecting means 66 a condenser lens, 67 a shutter

Claims (5)

In an optical modeling apparatus that forms a molded article of a desired shape by sequentially forming a cured layer by irradiating light to a liquid photocurable resin,
A drawing light source that emits a light beam having a predetermined wavelength for forming a cured layer by drawing the photocurable resin on the cured layer forming surface;
Scanning means for causing the light curable resin to scan the light beam emitted from the drawing light source;
A focus detection light source that emits a light beam having a wavelength different from that of the light beam emitted from the drawing light source and a wavelength that does not cure the photocurable resin;
Detecting means for detecting a light beam emitted from the focus detection light source and irradiated on the cured layer forming surface and reflected by the cured layer forming surface;
An optical modeling apparatus for adjusting a focus state of a light beam scanned by the scanning unit based on a detection result detected by the detection unit. Furthermore, it has a liquid level regulating plate that regulates the swing of the photocurable resin on the cured layer forming surface and transmits the light beam emitted from the drawing light source,
The light beam emitted from the light source for drawing and the light source for focus detection is guided from the liquid level regulating plate side with respect to the photocurable resin,
2. The light according to claim 1, wherein the liquid level regulating plate is formed with a reflective coating film that transmits the light beam emitted from the drawing light source and reflects the light beam emitted from the focus detection light source. Modeling equipment. The optical modeling apparatus according to claim 2, wherein the reflective coating film is a laminated film formed by alternately laminating layers made of MgF ₂ and layers made of ZrO ₂ . Furthermore, a light source for batch exposure that emits light irradiated for each predetermined region of the photocurable resin,
A spatial light modulation means for spatially modulating light emitted from the batch exposure light source to collectively expose a predetermined area on the photocurable resin;
The optical modeling apparatus according to claim 1, wherein each cured layer of the modeled object is formed by a light beam scanned by the scanning unit and light spatially modulated by the spatial light modulation unit. In the optical modeling method of forming a molded article of a desired shape by irradiating light to a liquid photocurable resin and sequentially forming a cured layer,
A drawing light source that emits a light beam of a predetermined wavelength for drawing the photocurable resin on the cured layer forming surface to form a cured layer is different from a light beam emitted from the drawing light source. A focus detection light source that emits a light beam having a wavelength and a wavelength that does not cure the photocurable resin,
A light beam emitted from the focus detection light source is irradiated onto the hardened layer forming surface, a light beam reflected by the hardened layer forming surface is detected by a detecting means, and based on a detection result detected by the detecting means. Light that adjusts the focus state of the light beam emitted from the drawing light source and scans the hardened layer forming surface by a scanning unit that scans the photocurable resin with the light beam emitted from the drawing light source. Modeling method.

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